JP2000139069A - Linear motor drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain accurate driving by suppressing the influence of a magnetic field generated by the energization of an armature coil, in a linear motor driving device provided with a field magnet, the armature coil which faces and reciprocates along the field magnet, and a driving controller which controls the energization to the armature coil. SOLUTION: This linear motor drive is provided with a counter 44 capable of detecting the position of an armature coil AC in the prescribed direction, a memory 46 capable of storing the information of a magnetic field generated by a field magnet at respective positions in a prescribed direction, a magnetic pole detecting part 45 capable of reading magnetic field information from the memory 46 based on the position of the armature coil AC detected by the counter 44, and detecting the polarity of the field magnetic pole of the armature coil AC at a prescribed position, and an energization controller 47 which detects the timing of the energization based on the polarity of the pole detected by the magnetic pole detecting part 45 and energizes the armature coil AC.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless linear motor and a linear motor driving device including the driving device.

[0002]

2. Description of the Related Art FIG. 31 shows a schematic sectional view of an example of a brushless linear motor. Linear motor LMP shown in FIG.
Is provided with a guide shaft 91 extending linearly in a predetermined direction. The guide shaft 91 is made of a magnetic material.
A field magnet FM in which the magnetic poles are alternately arranged is formed.

A ring-shaped armature coil AC is fitted around the guide shaft 91. The armature coil AC includes three ring-shaped coils of a U-phase coil Lu, a V-phase coil Lv, and a W-phase coil Lw. The armature coil AC faces the field magnet FM. The armature coil AC can reciprocate along the guide shaft 91 while facing the field magnet FM.

[0004] A shaft type linear motor is constituted by a field magnet FM formed on a shaft-shaped guide shaft 91 and an armature coil AC facing the field magnet FM. This linear motor is a so-called moving coil type linear motor using a field magnet FM as a motor stator and an armature coil AC as a motor mover. By energizing the armature coil AC, the armature coil AC
1 can be driven.

When a pulse is applied to each of the armature coils, the following field magnet information is detected and
Pulse current is applied to each coil of the armature coil AC based on the detected field magnet information. As the field magnet information, for example, a positional relationship in the longitudinal direction of the guide shaft between each coil of the armature coil AC and the magnetic pole of the field magnet FM facing the coil is detected. The polarity of the magnetic pole of the field magnet facing each coil is also detected as field magnet information.

In the linear motor LMP shown in FIG.
Is P at the left end in the drawing of each of the coils Lu, Lv, and Lw.
₁, P_Two, P_ThreePole of field magnet FM at each position
Field magnet information by detecting the polarity of
ing. Therefore, P₁, P _Two, P_ThreeAt each position
Hall element h as each magnetic sensor₁, H_Two, H_ThreeBut
Are located. These Hall elements are armature coils A
C and moves with the armature coil AC.
You. In the linear motor LMP, the armature coil AC
P on₁, P_Two, P_ThreeOf the field magnet at each position
In synchronization with the pole switching position, the timing shown in FIG.
By energizing each coil with thrust
The child coil AC can be moved along the guide shaft 91.
it can.

However, when the coils of the armature coil AC are energized to move the armature coil AC along the guide shaft 91, the field magnets FM are formed in the hall elements h ₁ , h ₂ and h _3. In addition to the generated magnetic field, the magnetic field formed by each coil of the armature coil AC also acts, and the following problems occur. Due to the magnetic field formed by the armature coil AC, the magnetic field detected by the Hall element moving along the guide axis together with the armature coil AC is distorted as shown in FIG. The Hall element detects the magnetic pole switching at a position advanced in the driving direction of the armature coil from the actual magnetic pole switching position of the field magnet FM. Since the switching position of the magnetic pole detected by the Hall element is out of phase with the actual switching position of the magnetic pole of the field magnet FM, each coil is synchronized at the timing shown in FIG. When power is supplied to the switch, it is synchronized with the switching of the magnetic pole of the field magnet,
Each coil cannot be energized, and the thrust fluctuation increases.

A similar problem also occurs when linearly energizing each of the armature coils. When linearly energizing each coil, a magnetic field formed by a field magnet acting on each coil is detected, and a current corresponding to the magnitude and direction of the detected magnetic field is applied to each coil. Therefore, if the detected magnetic field of the Hall element is distorted with respect to the magnetic field formed by the field magnet under the influence of the magnetic field formed by each coil of the armature coil as described above, each coil has a field acting on the coil. A current corresponding to the magnetic field formed by the magnetic magnet cannot flow, and the fluctuation in thrust increases.

In order to suppress such a problem caused by a magnetic field formed by an armature coil, the following method has been proposed. For example, JP-A-4-335
No. 65 proposes the following linear brushless DC motor. In this linear motor, a position information magnet is arranged parallel to the field magnet, separately from the field magnet. The position information magnet is formed at the same pitch as the magnetization pitch of the field magnet. The position information magnet is arranged in accordance with the polarity of the magnetic pole of the field magnet whose magnetic poles face each other.
The field magnet forms a trapezoidal wave magnetic field, and the position information magnet forms a sine wave magnetic field.
A magnetic field formed by the position information magnet is detected by a magnetic pole detection sensor (magnetic sensor), and the armature coil is energized linearly. In this linear motor, when a current corresponding to a trapezoidal wave-shaped magnetic field formed by a field magnet is applied to an armature coil, the thrust fluctuation is large. However, since the position information magnet forming the sine wave magnetic field is provided separately from the field magnet, the magnetic pole detection sensor can be arranged at a position where the influence of the magnetic field formed by the armature coil is small. The magnetic pole detection sensor can detect the formation magnetic field of the position information magnet without being substantially affected by the formation magnetic field of the coil.

For example, for example, "Linear Servo Motor and System Design" (Mana Shiraki et al., Sogo Denshi Publishing Co., Chapter 8)
Has proposed a linear motor capable of energizing pulses without using a magnetic sensor such as a Hall element, and a drive control device therefor. The drive control device includes a memory such as a ROM in which data indicating energization information of each coil of the armature coil is stored at each position in the longitudinal direction of the stator. The energization information is data indicating whether or not the coil is energized, and if energized, is data indicating the energization direction. The energization information for one cycle of each coil is stored in the memory. The linear motor has a linear encoder. The drive control device detects the position of each coil in the longitudinal direction of the stator using a linear encoder, reads the energization information for each coil at that position from the memory, and applies the information to each coil based on the read energization information. Turn on electricity. This linear motor is intended to reduce the cost of the linear motor because the cost of the linear motor increases when a plurality of expensive magnetic sensors are provided for each of the armature coils. However, in this way, it is possible to apply a pulse current to each coil without being affected by the magnetic field formed by each coil of the armature coil, and it is possible to drive the linear motor with a small change in thrust.

[0011]

However, the technique taught by JP-A-4-33565 has the following problems. The field magnet is usually formed by magnetizing a field magnet base made of a magnetic material using a magnetizing device, but is formed due to an error of the magnetizing device at the time of this magnetizing. Variations occur in the width of each magnetic pole of the field magnet. Similarly, the width of each magnetic pole of the position information magnet varies. Since the field magnet and the position information magnet are formed separately, variations in the widths of these magnetic poles are usually different, and a portion where the opposite magnetic poles of the field magnet and the position information magnet have different polarities is formed. Therefore, if the magnetic field formed by the position information magnet in such a portion is detected by the magnetic sensor and a current corresponding to the magnitude and direction of the detected magnetic field is supplied to the armature coil, the direction to be driven is determined. In this case, an electromagnetic force in the opposite direction is generated, and the thrust fluctuation is increased.

A similar problem also occurs in a linear motor taught by "Linear Servo Motor and System Design" and its drive control device. In this linear motor, if the width of each magnetic pole of the field magnet varies, the following problem occurs. The energization information stored in the memory stores only one cycle of energization information on the assumption that the width of each magnetic pole is the same width. Therefore, when the width of each magnetic pole of the field magnet varies, when power is applied to each coil based on the energization information read from the memory, a magnetic pole having a polarity opposite to the expected polarity faces the coil. In some cases, an electromagnetic force is generated in a direction opposite to the direction in which the motor should be driven, and the thrust fluctuation increases.

Therefore, the present invention can reciprocate along the field magnet, facing the field magnet and the field magnet in which the magnetic poles of the N pole and the magnetic pole of the S pole are alternately arranged linearly in a predetermined direction. A linear motor drive device comprising an armature coil and a drive control device for controlling energization of the armature coil, wherein the linear motor drive device has one or more of the following advantages (A) to (D). The task is to provide. (A) A linear motor drive device capable of accurately detecting a field magnet forming magnetic field at a predetermined position on a mover by suppressing the influence of a magnetic field formed by energization of an armature coil. (B) A linear motor drive device capable of accurately driving a linear motor while suppressing the influence of a magnetic field formed by energization of the armature coil. (C) A linear motor drive device capable of accurately detecting a field magnet forming magnetic field at a predetermined position on a mover, even if the width of each magnetic pole of the field magnet varies. (D) A linear motor driving device capable of driving a linear motor with higher accuracy than before, even if the width of each magnetic pole of the field magnet varies.

[0014]

In order to solve the above-mentioned problems, the present invention provides the following first to third types of linear motor driving devices. Hereinafter, each type of linear motor driving device will be described in order. (1) First-Type Linear Motor Driving Device A first-type linear motor driving device includes a field magnet in which N-poles and S-poles are alternately arranged linearly in a predetermined direction; An armature coil that can reciprocate along the field magnet; a linear encoder scale extending in the predetermined direction; an encoder sensor that moves together with the armature coil and faces the linear encoder scale; A position detection device capable of detecting a position of the armature coil in the predetermined direction from detection information of a sensor, and a memory for storing magnetic field information formed by the field magnet at each position in the predetermined direction. The magnetic field information from the memory based on the position of the armature coil in the predetermined direction detected by the position detecting device. A magnetic field detecting device that can read information and detect magnetic field information of the field magnet at a predetermined position in the predetermined direction on the armature coil; and a predetermined magnetic field on the armature coil detected by the magnetic field detecting device. A linear motor drive device comprising: a drive control device that controls energization of the armature coil based on magnetic field information at a position.

The first type of linear motor drive device includes a field magnet, an armature coil, a linear encoder scale, an encoder sensor, a position detection device, a memory, a magnetic field detection device, and a drive control device. The field magnet has N magnetic poles and S magnetic poles alternately arranged in a predetermined direction. The field magnet extends in a predetermined direction.

The armature coil faces the field magnet. The armature coil can reciprocate in a predetermined direction along the field magnet. By energizing the armature coil,
The armature coil can be moved in a predetermined direction. A linear motor is composed of the field magnet and the armature coil. This linear motor is a moving coil type linear motor using a field magnet as a motor stator and an armature coil as a motor mover. The linear motor is, for example, a shaft type linear motor in which a field magnet formed on a guide shaft extending in a predetermined direction is used as a motor stator, and an armature coil externally fitted to the field magnet (guide shaft) is used as a motor mover. be able to. The linear motor may be a plain linear motor in which a field magnet in which plate-shaped N-pole magnetic poles and plate-shaped S-pole magnetic poles are alternately arranged is used as a motor stator, and an armature coil facing the field magnet is used as a motor mover. Good.

The linear encoder scale (linear encoder chart) extends in a predetermined direction. The encoder sensor faces the encoder scale. The encoder sensor is directly or indirectly supported by the armature coil and moves in a predetermined direction integrally with the armature coil.

A linear encoder is composed of a linear encoder scale and an encoder sensor. The linear encoder may be an optical type or a magnetic type. The position detection device can detect the absolute position of the armature coil in a predetermined direction from the detection information (detection signal) of the encoder scale. The position detection device includes, for example, an encoder counter that counts up and down the number of encoder pulses detected by the encoder sensor according to the moving direction of the armature coil, and a home sensor for detecting a home position (reference position) in a predetermined direction. Have. The encoder counter counts up when the armature coil is moving in any one of predetermined directions, and counts down when it is moving in the opposite direction. In this case, the absolute position of the armature coil in a predetermined direction can be detected by counting the number of encoder pulses from the home position.

The memory is for storing magnetic field information (field magnet information) formed by the field magnet at each position in a predetermined direction. This field magnet information
It is obtained by measuring in advance. The field magnet information is information including the variation information when the width of each magnetic pole of the field magnet varies. The field magnet information is information on the entire length of the field magnet or the entire length of the movable range of the armature coil.
That is, the field magnet information is not information of only one cycle of the N pole and the S pole adjacent to each other in the field magnet.

The memory may store, for example, information indicating the direction and magnitude of a magnetic field formed by the field magnet at each position in a predetermined direction. As described below, when the drive control device controls the energization of the armature coil,
When only the direction of the magnetic field formed by the field magnet at each position in the predetermined direction (polarity of the magnetic pole) is necessary, only information indicating the direction of the magnetic field at each position in the predetermined direction is stored in the memory. You may keep it. In any case, the memory stores magnetic field information of a magnetic field formed by the field magnet, which is a magnetic field in which the armature coil generates an electromagnetic force in a predetermined direction when the armature coil is energized. .

The drive control device controls the energization when energizing the armature coil and moving the armature coil in a predetermined direction (one direction in the predetermined direction).
The drive control device controls the energization based on the magnetic field (the direction and / or the magnitude of the magnetic field) formed by the field magnet at a predetermined position on the armature coil in a predetermined direction. Information on the magnetic field formed by the field magnet at a predetermined position on the armature coil (field magnet information) is detected by a magnetic field detection device.

The magnetic field detecting device reads out magnetic field information of the field magnet from the memory based on the position of the armature coil in the predetermined direction detected by the position detecting device, and reads the field magnet at a predetermined position on the armature coil. Detect information. The predetermined position is a position on the armature coil (on the mover), and the predetermined position moves in a predetermined direction as the armature coil moves. The magnetic field information of the field magnet at a predetermined position on the armature coil is information of a magnetic field formed by the field magnet with respect to a predetermined position on the armature coil, in other words, a predetermined position on the armature coil. Information on the magnetic field formed by the acting field magnet.

The drive control device controls energization of the armature coil based on field magnet information at a predetermined position on the armature coil detected by the magnetic field detection device. For example, in the case of applying a pulse current to the armature coil, the drive control device detects an energization timing (an energization start position and an energization stop position) based on the field magnet information detected by the magnetic field detection device, and at that timing, What is necessary is just to pass a pulse current to a child coil. When the pulse current is applied and the full-wave current is applied to the armature coil, the drive control device detects the energizing direction to the armature coil based on the field magnet information detected by the magnetic field detection device, and determines the direction. A pulse current may be applied to the first. When pulse energization is performed, when field magnet information at two or more predetermined positions on the armature coil in a predetermined direction is required to detect the energization timing,
What is necessary is just to make the magnetic field detecting device detect the field magnet information at each predetermined position. When the pulse current is applied, usually only the direction of the magnetic field (polarity of the magnetic pole) is required as the field magnet information at a predetermined position on the armature coil (the magnitude of the magnetic field is not required). Only the information indicating the direction of the magnetic field at each of the positions may be stored. Further, in this case, even if the switching position of the direction of the magnetic field in the predetermined direction (the switching position of the polarity of the magnetic pole) is stored in the memory, the direction of the magnetic field at each position in the predetermined direction is detected by the magnetic field detection device. be able to.

When, for example, linearly energizing the armature coil, the drive control device detects the direction of energization to the armature coil and the magnitude of the current to be energized based on the field magnet information detected by the magnetic field detection device. Then, the current having these directions and magnitudes may be supplied to the armature coil. In the first type of linear motor driving device, when the armature coil is energized and moves in a predetermined direction along the field magnet, the armature coil at a predetermined position on the armature coil is moved. The magnetic field acting on the magnetic field is detected by the magnetic field detection device from the magnetic field information stored in the memory based on the position of the armature coil in the predetermined direction detected using the linear encoder and the position detection device. It is possible to detect the magnetic field by suppressing the influence of the magnetic field formed by the sub-coil by energization. Therefore, the magnetic field acting on the armature coil at a predetermined position on the armature coil can be detected with high accuracy, and the drive control device can control the energization with high accuracy.

Even if the width of each magnetic pole of the field magnet varies, the field magnet information stored in the memory is the field magnet information including the variation information. Energization control can be performed well. (2) Second Type Linear Motor Driving Device The second type linear motor driving device includes a field magnet in which N magnetic poles and S magnetic poles are alternately arranged linearly in a predetermined direction; An armature coil that can reciprocate along the field magnet, and magnetic poles of N and S poles are alternately arranged in the predetermined direction, and a magnetic field formed by the field magnet in the predetermined direction. And a magnetic sensor that moves together with the armature coil to form a magnetic field proportional to the magnetic scale and faces the magnet scale, and energization control to the armature coil based on a magnetic field formed by the magnet scale detected by the magnetic sensor. And a drive control device for performing the following.

The second type of linear motor drive device includes a field magnet, an armature coil, a magnet scale, a magnetic sensor, and a drive control device. The field magnet and the armature coil are the same as those of the first type linear motor driving device. The magnet scale extends in a predetermined direction. Like the field magnet, the magnet scale has N magnetic poles and S magnetic poles alternately arranged in a predetermined direction. The magnet scale forms a magnetic field proportional to the magnetic field formed by the field magnet at each position in a predetermined direction. At each position in the predetermined direction, the magnetic field formed by the magnet scale and the magnetic field formed by the field magnet are proportional,
Each position where the magnitude of the magnetic field formed by the field magnet becomes 0, in other words, each switching position of the magnetic pole is the same position in the predetermined direction as each switching position of the magnetic pole of the magnetic field formed by the magnet scale. When the width of each magnetic pole of the field magnet varies, the width of each magnetic pole of the magnet scale also varies.

Such a magnet scale can be formed, for example, by the following method. When the field magnet is formed by magnetizing a field magnet substrate made of a magnetic material, for example, a magnet scale is formed by magnetizing a magnet scale substrate made of a magnetic material at the same time as the field magnet substrate. do it. At this time, the field magnet and the magnet scale may be formed by simultaneously magnetizing both the bases while the magnet scale bases are temporarily attached to the field magnet bases in a removable manner. For example, a sealing material is pasted on one surface of a magnet scale base, and the magnet scale base is pasted on the field magnet base with the sealing material and simultaneously magnetized, so that the field magnet and the magnet scale are magnetized. May be formed. With this configuration, when the magnet scale base on which the magnet scale is formed is arranged so as to extend in a predetermined direction, the magnet scale can be arranged using the sealing material, and the magnet scale can be easily arranged accordingly. Further, the magnet scale may be formed by making the magnet scale base made of a magnetic recording material close to or in contact with a field magnet formed in advance. Examples of the magnetic recording material include a magnetic recording tape for recording music.

The magnetic sensor faces the magnet scale. The magnetic sensor is directly or indirectly supported by the armature coil, and moves in a predetermined direction integrally with the armature coil. As the magnetic sensor, for example, a Hall element, M
R element can be mentioned. In the second type of linear motor drive device, the drive control device controls energization of the armature coil based on magnetic field information detected by the magnetic sensor. The drive control device of the second type linear motor drive device may perform pulsed or linear current supply to the armature coil, similarly to the drive control device of the first type linear motor drive device.

Since the magnetic sensor faces the magnet scale, the drive control device controls the energization based on the magnetic field formed by the magnet scale. As described above, the magnetic field formed by the magnet scale is proportional to the magnetic field formed by the field magnet at each position in a predetermined direction. The energization control can be performed.

Since the magnetic sensor faces the magnet scale, the magnetic sensor can be arranged at a position where the effect of the magnetic field formed by the energization of the armature coil on the magnetic sensor is suppressed. For example, a magnetic shield member may be arranged between the magnetic sensor and the armature coil. In this way, by suppressing the action of the magnetic field formed by the armature coil on the magnetic sensor, the magnetic sensor generates a magnetic field formed by the magnet scale, in other words, a magnetic field proportional to the magnetic field formed by the field magnet. Detection can be performed with high accuracy, and accordingly, the drive control device can perform energization control with high accuracy.

Further, even if the width of each magnetic pole of the field magnet varies, as described above, the width of each magnetic pole of the magnet scale also varies in the same manner as the width of each magnetic pole of the field magnet. The drive control device can perform the energization control with higher accuracy. (3) Third-Type Linear Motor Driving Device A third-type linear motor driving device includes a field magnet in which N-poles and S-poles are alternately arranged linearly in a predetermined direction; An armature coil that can reciprocate along the field magnet; a linear encoder scale extending in the predetermined direction; an encoder sensor that moves with the armature coil and faces the linear encoder scale; An encoder counter that counts up and down the number of encoder pulses detected by the sensor in accordance with the moving direction of the armature coil; and an encoder counter supported by the armature coil and at a predetermined position in the predetermined direction on the armature coil. A magnetic sensor for detecting a magnetic field formed by the field magnet acting on the armature coil; When the armature coil is energized and the armature coil is moved along the field magnet, a switching position of a magnetic pole of a magnetic field formed by the field magnet at a predetermined position on the armature coil and The error distance D _E between the magnetic field detected by the magnetic sensor and the switching position of the corresponding magnetic pole is corrected based on the encoder count number counted by the encoder counter, and is corrected at a predetermined position on the armature coil. A correction device for detecting a switching position of a magnetic pole of a magnetic field formed by the field magnet, and a switching position of a magnetic pole at a predetermined position on the armature coil detected by the correction device, based on the switching position of the armature coil. And a drive control device for controlling the energization of the linear motor.

The third type of linear motor driving device includes a field magnet, an armature coil, a linear encoder scale, an encoder sensor, an encoder counter, a magnetic sensor, a correction device, and a drive control device. The field magnet, the armature coil, the linear encoder scale, and the encoder sensor are the same as those of the first type linear motor driving device.

The encoder counter counts up and down the encoder pulse detected by the encoder sensor according to the moving direction of the armature coil. The encoder counter counts up when the armature coil is moving in any one of predetermined directions, and counts down when it is moving in the opposite direction. The magnetic sensor faces the field magnet in the third type of linear motor driving device. The magnetic sensor is directly or indirectly supported by the armature coil, and moves in a predetermined direction integrally with the armature coil. Examples of the magnetic sensor include a Hall element and an MR element.

The magnetic sensor moves integrally with the armature coil to detect a magnetic field formed by a field magnet acting on the armature coil at a predetermined position in a predetermined direction on the armature coil. The magnetic sensor does not necessarily need to be arranged at a predetermined position on the armature coil in a predetermined direction as described later. The magnetic sensor may be arranged at a position shifted from a predetermined position on the armature coil in a predetermined direction.

When the armature coil is energized and the armature coil is moved along the field magnet, the switching position of the magnetic pole of the magnetic field detected by the magnetic sensor is determined by the field at a predetermined position on the armature coil. The magnetic field formed by the magnet may deviate from the switching position of the corresponding magnetic pole. The error distance _DE is caused by a magnetic field formed by energization of the armature coil, a deviation between a predetermined position on the armature coil in a predetermined direction and an arrangement position of the magnetic sensor, and the like.

This error distance D _E is corrected by a correction device. The correction device corrects a deviation of the error distance D _E based on the encoder count number counted by the encoder counter, and detects a switching position of a magnetic pole formed by a field magnet at a predetermined position on the armature coil. . The correction device can correct the error distance _DE as follows, for example, and detect the switching position of the magnetic pole of the magnetic field formed by the field magnet at a predetermined position on the armature coil.

Here, the switching position of the magnetic pole of the magnetic field formed by the field magnet at a predetermined position on the armature coil is greater than the switching position of the corresponding magnetic pole of the magnetic field detected by the magnetic sensor. The error distance _DE is positive (positive value) when the position is advanced in the direction, and negative (negative value) when the position is delayed. When the error distance _DE is positive, in other words, when the corresponding magnetic pole of the magnetic field formed by the field magnet at a predetermined position on the armature coil switches after the magnetic sensor detects the switching of the magnetic pole, correction is performed. The device is configured such that the armature coil moves a distance D in the driving direction from the switching position of the magnetic pole detected by the magnetic sensor.
_{At the} advanced position, correction for switching the magnetic poles may be performed in the same manner as the switching of the magnetic poles detected by the magnetic sensor.
Switching the magnetic poles in the same manner refers to, for example, switching the magnetic poles from the N pole to the S pole when the magnetic sensor detects the switching of the magnetic poles from the N pole to the S pole. The fact that the armature coil has advanced the distance _{DE in the} driving direction can be detected by a change in the encoder count number counted by the encoder counter corresponding to the distance _DE . By performing the correction in this manner, even if the magnetic field formed by the armature coil acts on the magnetic sensor, the correction device determines the switching position of the magnetic pole formed by the field magnet at a predetermined position on the armature coil. It can be detected with high accuracy. When the error distance _DE is positive, the correcting device switches the magnetic pole of the magnetic field formed by the field magnet at a predetermined position on the armature coil even if the width of each magnetic pole of the field magnet varies. The position can be accurately detected.

Error distance D_EWhen is negative, paraphrase
Then, the field magnet at a predetermined position on the armature coil
After switching the magnetic pole of the magnetic field to be formed, the magnetic sensor
When detecting the switching of the corresponding magnetic pole,
The field magnet at the predetermined position on the armature coil is
The next magnetic pole switching position of the magnetic field to be formed can be detected
Thus, the correction may be made as follows. Error distance D_EIs negative
When the correction device is
The armature coil moves in the drive direction from the pole switching position.
Release (M_W− | D_E|) Magnetic sensor detects at advanced position
Compensation to switch the magnetic poles in the opposite direction
Just do it. Where M_WIs one pole of the field magnet
Width. Conversely, switching magnetic poles means, for example,
The sensor detects that the magnetic pole has switched from N pole to S pole
Means switching the magnetic pole from the S pole to the N pole.
The armature coil is moved a distance (M_W− | D_E｜)
That is, the encoder that the encoder counter counts
The count number is the distance (M _W− | D_ED) corresponding to |
Can be detected by the change in the encoder count.
Wear. By correcting in this way, an armature coil is formed.
Even if a magnetic field that acts on the magnetic sensor,
The magnetic field formed by the field magnet at a predetermined position on the child coil
It is possible to accurately detect the switching position of the magnetic pole of the field
Wear.

As described above, the error distance D_EIs the armature
The magnetic field formed by the current
Deviation between the position of the air sensor and the specified position on the armature coil
Caused by The correction device calculates the error distance D_EFor example
Next distance D_EAAnd distance D_ECSum of (D_EA+ D_EC)
The correction may be performed in the same manner as described above. Distance D_EAIs the prescribed one
Position on the armature coil and orientation of the magnetic sensor
Is the distance from the position of the arrangement. Distance D_EAIs a magnetic sensor
Position is smaller than the specified position on the armature coil.
Positive and slow when the position is advanced in the child coil drive direction.
If it is at the shifted position, it is negative. In other words, the distance D
_EAIndicates that the position of the magnetic sensor is
Is located downstream of the armature coil driving direction.
Sometimes positive and negative when upstream. Magnetic sensor
The distance D _EAPosition is 0, positive position, negative position
May be arranged at any position.

The distance D _EC is energized the armature coil, when moving along the armature coils to the field magnet, at the position where the magnetic sensor is placed, the magnetic poles of the magnetic field field magnet is formed Of the corresponding magnetic pole detected by the magnetic sensor. The distance _DEC is determined by the fact that the switching position of the magnetic pole formed by the field magnet at the position where the magnetic sensor is located is greater than the switching position of the corresponding magnetic pole of the magnetic field detected by the magnetic sensor in the driving direction of the armature coil. Positive when the position is advanced to, and negative when the position is delayed.

The error distance D _E = D _EA + D _EC > 0 (the distance D _E
When the value is positive), the correction device can accurately detect the switching position of the magnetic pole of the magnetic field formed by the field magnet at a predetermined position on the armature coil by performing the same correction as described above. Error distance D _E = D _EA + D _EC <0
Even when the distance D _E is negative, the correction device performs the same correction as described above to accurately determine the switching position of the magnetic pole formed by the field magnet at a predetermined position on the armature coil. Can be detected.

The error distance D _E = D _EA + D _EC may optionally also be zero. At this time, the correction device
At the position where the magnetic sensor detects the switching of the magnetic pole, the magnetic pole may be switched in the same manner as the switching of the magnetic pole detected by the magnetic sensor. In this case, the correction device does not need to perform the above correction. The distance D _EC, may vary depending on the magnitude of current supplied to the armature coils (energization amount). Therefore, the error distance D _E = D _EA + D
_EC may also change depending on the amount of current supplied to the armature coil. Correction apparatus, the value of the distance D _EC vary depending on the amount of current supplied to the armature coils may be corrected as described above.

The drive control device of the third type of linear motor drive device, based on the switching position of the magnetic pole detected by the correction device, performs the same operation as the drive control device of the first type of linear motor drive device. Energization control is performed. Typically, the drive control device detects the energization timing of the armature coil based on the switching position of the magnetic pole at a predetermined position on the armature coil detected by the correction device, and applies a pulse current to the armature coil. Just fine.

As described above, the correcting device can accurately determine the switching position of the magnetic pole formed by the field magnet at a predetermined position on the armature coil even if the magnetic field formed by the armature coil acts on the magnetic sensor. Since the detection can be performed well, the drive control device can control the energization of the armature coil with higher accuracy. Further, as described above, when the error distance _DE is positive, even if there is variation in the width of each magnetic pole of the field magnet, the correction device forms the field magnet at a predetermined position on the armature coil. It is possible to accurately detect the switching position of the magnetic pole of the generated magnetic field.
Therefore, when the error distance D _E is positive, the drive control device can control the energization of the armature coil with higher accuracy even if the width of each magnetic pole of the field magnet varies.

The magnetic sensor is arranged at a position where the error distance _DE becomes zero when a current having a predetermined current value is passed through the armature coil to move the armature coil along the field magnet. Is also good. The predetermined current value may be, for example, a maximum current value that flows through the armature coil. The predetermined current value may be, for example, a current value supplied to the armature coil when the armature coil is moved at a predetermined constant speed. If you place the magnetic sensor in such a position,
As described above, the correction device does not need to perform such correction.

Therefore, when the magnetic sensor is arranged at a position where the error distance D _E = 0, no correction device is required. Further, there is no need for an encoder counter used when the correction device performs correction. Furthermore, the linear encoder and encoder sensor used by the encoder counter are:
It is not necessary to detect the magnetic field formed by the field magnet at a predetermined position on the armature coil.

Accordingly, a field magnet in which N-poles and S-poles are alternately arranged linearly in a predetermined direction, and an electric machine which faces the field magnet and can reciprocate along the field magnet A magnetic sensor that moves with the armature coil and detects a magnetic field formed by the field magnet acting on the armature coil at a predetermined position in the predetermined direction on the armature coil; A drive control device that controls energization of the armature coil based on magnetic field information detected by the magnetic sensor,
The magnetic sensor is configured such that, when a current having a predetermined current value flows through the armature coil to move the armature coil along the field magnet, the magnetic field at a position where the magnetic sensor is disposed, It is disposed at a position shifted from the predetermined position on the armature coil in the predetermined direction by a distance between the switching position of the magnetic pole of the magnetic field formed by the magnetic magnet and the switching position of the corresponding magnetic pole detected by the magnetic sensor. In the linear motor driving device described above, the drive control device can accurately control energization in the following cases.

In this linear motor driving device, when the current supplied to the armature coil has a predetermined current value, the error distance _DE becomes zero, so that the magnetic field formed by the armature coil acts on the magnetic sensor. However, the magnetic sensor can accurately detect the switching position of the magnetic pole of the magnetic field formed by the field magnet at a predetermined position on the armature coil. Accordingly, the drive control device can control the energization with higher accuracy. When the distance _DEC is negative, for example, the magnetic sensor may be arranged at a position where | _DEC | = | _DEA | and the distance _DEA > 0. This linear motor drive includes a correction device, a linear encoder,
Since no encoder counter is required, the cost can be reduced accordingly. If the predetermined current value is a current that flows when the armature coil is moved at a predetermined constant speed, the linear motor drive device must drive accurately when moving the armature coil at a predetermined constant speed. Can be. For example, when this linear motor drive device is used for driving a carriage on which optical components are mounted in an optical image reading device such as an image scanner, the carriage is moved at a constant speed during image reading. In such a case, the carriage can be driven with less speed fluctuation than the conventional linear motor driving device.

[0049]

Embodiments of the present invention will be described below with reference to the drawings. (1) FIG. 1 shows a schematic side view of a linear motor LM1 according to the present invention. FIG. 2 is a schematic sectional view of the linear motor LM1 taken along line XX of FIG. FIG. 3 is a schematic block diagram of a drive control device 4A according to the present invention for controlling the drive of the linear motor LM1. The linear motor LM1 and the drive control device 4A provide a linear motor drive device according to the present invention.

The linear motor LM1 is a shaft type linear motor as described below, and is a moving coil type linear motor. The linear motor LM1 includes a guide shaft 1 that extends linearly in a predetermined direction. The guide shaft 1 has both ends supported by the apparatus frame FR. The guide shaft 1 is made of a magnetic material. The guide shaft 1 is made of Mn-Al in this example. The guide shaft 1 is magnetized as follows using the magnetizing device shown in FIGS. 4A and 4B, and the guide shaft 1 has N magnetic poles and S magnetic poles arranged alternately. A field magnet FM is formed.

FIG. 4A is a schematic perspective view of the magnetizing device, and FIG. 4B is a schematic sectional view of the magnetizing device. The magnetizing device has a cylindrical pipe 81 made of a nonmagnetic material. A coil 82 having a predetermined width is provided on the outer peripheral surface of the pipe 81.
1, 822, 823, 824, ... are wound.
Adjacent coils are wound around the pipe 81 in opposite directions. For example, coil 822 includes coils 821 and 823
Is wound around the pipe 81 in the opposite direction. The predetermined width of these coils in the pipe longitudinal direction is one magnetic pole width _Mw of the field magnet FM to be formed. In this example, M _w =
30 mm.

The guide shaft 1 (field magnet base) is disposed inside the hollow of the pipe 81 and magnetized. Each of the magnetizing coils 821, 822, 823, 824,.
When a high voltage is applied so that a current flows in a direction opposite to that of an adjacent coil, the field magnet F
M can be formed. The field magnet FM thus formed forms a salient pole-shaped magnetic field in the longitudinal direction of the guide shaft as shown in FIG. 5 in this example. Further, the width of each magnetic pole of the field magnet FM is approximately M _W (in this example, approximately 30 mm).

The guide shaft 1 on which the field magnet FM is formed constitutes a stator LMs of the linear motor LM1. A movable element LMm that reciprocates along the guide shaft 1 is fitted to the stator LMs. The mover LMm includes an armature coil AC, a yoke 31, and bearings 321 and 322.
have.

The armature coil AC has a ring shape fitted to the stator LMs, and faces the field magnet FM.
The yoke 31 has a cylindrical shape that fits over the stator LMs, and has an armature coil AC disposed therein. The armature coil AC is supported by the yoke 31. Yoke 31
Is made of a ferromagnetic material. The yoke 31 is made of iron in this example. The bearings 321 and 322 are respectively connected to the yoke 31.
Are disposed in the openings at both ends. Thus, the mover LMm can reciprocate along the stator LMs (guide shaft 1).

In this example, the armature coils AC are U, V and
And three coil groups with three coils of phase W and W
The first set of coil groups, the second set of coil groups, the third set
Are arranged in the stator longitudinal direction in this order.
The first group of coils is a coil L_U1, L_V1And L_W1From
In this order, they are arranged in the longitudinal direction of the stator. 2nd set
The coil group of_U2, L_V2And L_W2Consisting of
In the longitudinal direction of the stator. 3rd carp
Le group is L_U3, L_V3And L_W3And in this order the stator
They are arranged in the longitudinal direction. Both coils are used in this example.
Is M _W/ 3 width. These 9
The three coils all have center positions M _WShift by / 3
It is arranged.

The coils of the armature coil AC are connected as shown in FIG. 3 in this example. Each set of U-phase coil L
_U1, L _U2 and L _U3 are connected in parallel. Coil L
_U2 is wound relative to the stator LMs in the opposite direction to the coil L _U1 and L _U3. The V-phase coils L _V1 , L _V2 and L _V3 of each set are connected in parallel. The coil L _V2 is wound around the stator LMs in the opposite direction to the coils L _V1 and L _V3 . The W-phase coils L _W1 , L _W2, and L _W3 of each set are connected in parallel. Coil L _W2 is _equal to coils L _W1 and L _W3
And wound around the stator LMs in the opposite direction. The U-phase, V-phase and W-phase coils thus connected in parallel are star-connected.

A linear encoder chart (linear encoder scale) Ec is arranged parallel to the guide shaft 1. The encoder chart Ec is a magnetic encoder chart in this example, in which N magnetic poles and S magnetic poles are alternately arranged at a predetermined pitch in the longitudinal direction of the guide shaft. The encoder pitch Ep of the encoder chart Ec is 100 μm in this example.

On the mover LMm, two encoder sensors Esa and Esb are arranged. The encoder sensors Esa and Esb both face the encoder chart Ec and move integrally with the mover LMm.
The encoder sensors Esa and Esb are displaced by Ep / 4 in the longitudinal direction of the encoder chart Ec (the longitudinal direction of the guide shaft). Encoder sensors Esa and E
sb is an MR sensor in this example. The detection signals of the encoder sensors Esa and Esb are input to the drive control device 4A shown in FIG. Although not shown in FIGS. 1 and 2, the drive control device 4A is disposed on the mover LMm. The drive control device 4A will be described later.

On the mover LMm, a light shielding member HI is further provided.
Is arranged. When the mover LMm moves along the guide shaft 1, a home sensor Hs is disposed at a position where the light blocking member HI passes. Home sensor Hs
It is arranged near the left end in FIG. 1 in the longitudinal direction of the guide shaft. The home sensor Hs is supported at a fixed position by a support member (not shown). Home sensor Hs
In this example, the light-emitting element and the light-receiving element are so-called photo-interrupters arranged separately from each other. When the light blocking member HI is at a position facing the home sensor Hs, the home sensor H
Light emitted from the light emitting element of s toward the light receiving element is blocked by the light blocking member HI. Therefore, the home sensor H
s can detect that the light shielding member HI (movable element LMm) is at a position facing the home sensor Hs. Hereinafter, this position is called a home position. The mover LMm is reciprocated on the right side in FIG. 1 from the home position.
The detection signal of the home sensor Hs is input to the drive control device 4A shown in FIG.

The drive control device 4A for controlling the drive of the linear motor LM1 will be described with reference to FIG.
In this example, the linear motor LM is controlled by the drive control device 4A.
1 can be PLL driven. Drive control device 4
A includes a drive command unit 41, a PLL control unit 42, a compensation circuit unit 43, an encoder counter 44, a magnetic pole detection unit 45, a memory 46, a conduction control unit 47, and a three-phase full-wave conduction circuit 48.

The encoder signals detected by the encoder sensors Esa and Esb are input to a PLL controller 42 and an encoder counter 44. Note that the encoder signals detected by the encoder sensors Esa and Esb are both amplified by an amplifying / square-wave circuit (not shown) and converted to a square-wave signal (digital signal).
The signals are input to the LL control unit 42 and the encoder counter 44.

The encoder counter 44 can detect the moving direction (left or right in FIG. 1) of the mover LMm from the two encoder signals detected by the encoder sensors Esa and Esb. Encoder counter 4
Reference numeral 4 can count up / down the number of pulses of the encoder signal detected by the encoder sensor Esa. When the mover LMm is moving rightward in FIG. 1, the encoder counter 44 counts up the number of pulses of the encoder signal. Further, when the mover LMm is moving leftward in FIG. 1, the encoder counter 44 counts down the number of pulses of the encoder signal.

The encoder counter 44 also receives a detection signal from the home sensor Hs. The encoder counter 44 resets the encoder count value to “0” when the mover LMm is at the home position and the light blocking member HI is detected by the home sensor Hs. Therefore, the encoder count value after the reset indicates the position of the light shielding member HI on the mover LMm in the guide shaft longitudinal direction. That is, the position of the light shielding member HI on the mover LMm in the longitudinal direction of the guide shaft can be detected by the encoder counter 44 and the like.

Encoder count value V_eIs V_e= K
When (k is 0 or a natural number), the mover LMm
The light shielding member HI (strictly speaking, in this example, the light shielding member H
I at the left end in FIG. 1) is the home in the longitudinal direction of the guide shaft.
Distance k · Ep (Ep is an encoder) from a certain position of the sensor Hs.
1 in the right direction in FIG. Yes
The left end position of the light shielding member HI on the moving element LMm is set to the position P.₀Toss
You. In the following description, on the mover (armature coil)
Position P₀The encoder count value indicating_e(P ₀)When
I do.

The encoder count value counted by the encoder counter 44 is input to the magnetic pole detector 45.
The memory 46 stores field magnet information (field magnet data) of the field magnet FM. The memory 46 stores the field magnet information for the entire length of the field magnet FM, instead of the field magnet information for only one period of the field magnet FM. When the field magnet FM is formed by magnetizing the guide shaft 1 (field magnet base) using the magnetizing device shown in FIG. in other words, when each pole width of the field magnet FM is not in a predetermined width M _W is in the memory 46 field magnet information including the variation of the pole width has been stored. The field magnet information including the variation of the magnetic pole width is measured and stored in the memory 46 in advance. The field magnet information stored in the memory 46 can be measured, for example, as described later.

The memory 46 is a 16-bit memory in this example as shown in FIG. Data indicating the polarity of the magnetic pole of the field magnet FM at the position P ₀ on the mover LMm is stored in the memory 46 by associating the encoder count value with the memory address and the number of digits in the address as follows. Is stored. In this example, the north pole corresponds to data “1”, and the south pole corresponds to data “0”.

When the encoder count value V _e (P ₀ ) is 0 to
Data indicating the polarity of the field magnet FM magnetic pole at each position 15 is stored in order in the most significant bits from the least significant bit of the address 0000 _H. Data indicating the polarity of the magnetic pole of the field magnet FM at each position where the encoder count value V _e (P ₀ ) is 16 to 31 is an address 0001.
_H are stored in order from the least significant bit to the most significant bit. Data when the encoder count value V _e (P ₀ ) is 32 or more is stored in the same position.

Therefore, the encoder count value V
_The data that indicates the polarity of the magnetic pole of the field magnet FM at the position of V _e = K is represented by the address Int ((K−1) / 1).
6), stored at the [{Mod ((K−1) / 16)} + 1] bit. Incidentally, the function Int (x ₁ / x ₂₎
Is a function for obtaining a value rounded down operation result of x ₁ / x _2. The function Mod (x ₁ / x ₂ ) is expressed as x
Is a function for obtaining the remainder of the ₁ / x _2.

In addition to the encoder count value from the encoder counter 44, the drive command
From 1, a driving direction signal indicating the direction in which the mover LMm should be driven (left direction or right direction in FIG. 1) is input. Based on the encoder count value input from the encoder count 44, the magnetic pole detector 45 determines the field magnet at the next three positions on the mover LMm (on the armature coil AC) according to the driving direction of the mover LMm. Data indicating the polarity of the magnetic pole of the FM is read out from the memory 46 and is read out from the energization control unit 4.
7 is output. As the memory 46, for example, a DRAM with a short lead time can be used. When a DRAM is adopted as the memory 46, another RO than the memory 46 is used.
The field magnet information stored in a memory such as M or a storage device such as a hard disk may be transferred to the DRAM before driving the linear motor LM1.

The magnetic pole detection section 45 moves the mover LMm in FIG.
When driving to the right, the next P ₁, P_Two, P_ThreeThree
The data at one position is read from the memory 45. Position P₁
Is the coil L_U1The center position in the longitudinal direction of the guide shaft
1 in the left direction (the direction opposite to the driving direction) in FIG._W/ 6
Position on the mover (armature coil). Position P _Two
Is the coil L_V1The center position in the longitudinal direction of the guide shaft
1 in the left direction (the direction opposite to the driving direction) in FIG._W/ 6
Position on the mover (armature coil). Also rank
Place P_ThreeIs the coil L_W1Center of the guide shaft in the longitudinal direction
M from the position to the left in FIG. 1 (the direction opposite to the driving direction)_W
This is a position on the mover (armature coil) shifted by / 6.

The magnetic pole detection unit 45 moves the mover LMm in FIG.
When driving to the left, position P _Two, P_ThreeAnd next place
Place P_FourData from the memory 45 at the three positions
You. Position P_FourIs the coil L_W1In the longitudinal direction of the guide shaft
1 from the center position to the right (the direction opposite to the driving direction)
To M_W/ 6 position on the mover (armature coil)
You. Here, the aforementioned position P_TwoIs the coil L_U1Guide shaft
From the center position in the longitudinal direction to the right direction in FIG.
M)_W/ 6 position on the mover
You. The position P_ThreeIs the coil L_V1Guide shaft length
From the center position in the hand direction to the right direction in FIG.
In the opposite direction)_W/ 6 position on the mover
You.

The position P ₁ on the mover is the position P on the mover.
₀ (the left end in FIG. 1 of the light shielding member HI) is a distance D _{1 in the} right direction.
Since the position is distant, the encoder count value V _e (P ₁ ) indicating the position P ₁ is V _e (P ₁ ) = V, where the encoder count number corresponding to the distance D ₁ is _Ne (D ₁ ).
_e (P ₀ ) + N _e (D ₁ ). The magnetic pole detection unit 45 includes:
The data at the position where the encoder count value is V _e (P ₁ ) is read from the memory 45 as described above. The data, field magnet FM at the position P ₁ on the movable element LMm
Indicates the polarity of the magnetic pole. Similarly, the magnetic pole detection unit 45
Data indicating the polarity of the field magnet FM at the positions P ₂ , P ₃ and P ₄ on the mover can be read. The data at the three positions read according to the driving direction of the mover LMm is input to the energization control unit 47.

The energization control unit 47 further includes a drive command unit 4
The driving direction signal is also input from 1. The energization control unit 47
Based on the drive direction signal from the field magnet information and driving instruction unit 41 from the magnetic pole detection unit 45 controls the transistor Q ₁ to Q ₆ of the three-phase full-wave current supply circuit 48, the armature coils AC at the next timing Of the first set of coil groups L _U1 and L _V1
And L _W1 is pulsed.

For example, the mover LMm is driven rightward in FIG.
To operate, the energization control unit 47
L_U1, L_V1And L_W1Turn on electricity. FIG. 7 shows the mover LMm.
Out of the magnetic pole detection unit 45 when driving in the right direction in FIG.
Forced position P₁, P_Two, P _ThreeField magnet at each position
And a signal indicating the polarity of the magnetic pole of the
The phase relationship of the imaging and the direction of energization to each coil are shown.

The coil L _U1 has a “+” direction (N) from the position at which the magnetic pole at the position P ₁ switches from the S pole to the N pole to the position at which the magnetic pole at the position P ₂ switches from the N pole to the S pole. The direction in which the coil facing the pole generates electromagnetic force in the right direction in FIG. 1)
And the magnetic pole at the position P ₁ is shifted from the N pole to S
From the position after switching the poles, to a position where the magnetic poles are switched to the N pole from the S pole at position P _2, "-" current in the direction (the direction in which the coil that faces the S pole is generated an electromagnetic force in the right direction in FIG. 1) Flow. A current in the “+” direction flows through the coil L _V1 from the position at which the magnetic pole at the position P ₂ switches from the S pole to the N pole to the position at which the magnetic pole at the position P ₃ switches from the N pole to the S pole. , from the position where the magnetic pole is switched from the N pole to the S pole at position P _2, to a position where the magnetic pole at the position P ₃ switched to the N pole from the S-pole, - flow direction of the current "". Coil L
A current in the “+” direction is applied to _W1 from the position at which the magnetic pole at the position P ₃ switches from the S pole to the N pole to the position at which the magnetic pole at the position P ₁ switches from the S pole to the N pole. From the position where the magnetic pole at P ₃ switches from N pole to S pole,
A current in the “−” direction is applied to the position where the magnetic pole at the position P ₁ switches from the N pole to the S pole.

In the second coil group and the third coil group of the armature coil AC, since these coils are connected in parallel with the coils of the first coil group as described above, A pulse current flows at the same timing as each coil. When driving the mover LMm in the left direction in FIG. 1, the energization control unit 47 energizes each coil at the same timing as when driving the mover LMm in the right direction based on the magnetic poles at the positions P ₂ , P ₃ , and P _4. I do. FIG. 8 shows the polarities of the magnetic poles of the field magnet FM at the positions P ₂ , P ₃ , and P ₄ output from the magnetic pole detection unit 45 when the mover LMm is driven leftward in FIG. The phase relationship between the signal and the energization timing to each coil and the energization direction to each coil are shown.

By energizing at such a timing,
If the width of each magnetic pole of the field magnet FM is M _W (if no variation in the width of each magnetic pole of the field magnet FM),
In each coil of the armature coil AC, the center position of the coil in the guide shaft longitudinal direction (stator longitudinal direction) is shifted from a position advanced in the P _m / 6 drive direction from the drive direction upstream end of the magnetic pole facing the coil. , between positions to further proceed to 2P _m / 3 drive direction, the pulse current orientation of the coil generates an electromagnetic force in the driving direction is flowed. In order to energize each coil in this manner, the polarity of the magnetic pole at each of the three positions on the mover LMm is detected according to the driving direction as described above. Each coil of the armature coil AC has N
No power is supplied when facing both magnetic poles, the S pole and the S pole.
It is energized only when it faces only one of the poles or the south pole. Thereby, the thrust fluctuation can be suppressed.

The magnitude of the current supplied to each coil is controlled as follows. The drive command unit 41 can output a reference clock signal having a frequency according to the target speed of the mover LMm of the linear motor LMm. The drive command unit 41 receives a command from a host device (not shown), and
And outputs a reference clock signal having a frequency corresponding to the target speed. The reference clock signal is input to the PLL control unit 42.

An encoder signal indicating the actual moving speed of the mover LMm output from the encoder sensors Esa and Esb is input to the PLL controller 42. The PLL control section 42 outputs a signal corresponding to the phase difference between the reference clock signal and the encoder signal to the compensation circuit section 43. In the compensating circuit 43, the lead / lag compensation of the transmission system is performed, and the compensated signal corresponding to the phase difference between the reference clock signal and the moving speed signal is input to the energization control unit 47.

The power supply controller 47 supplies a current having a magnitude corresponding to the signal output from the compensation circuit 63 to each coil. The energization control unit 47 controls the magnitude of the energization current to each coil by performing PWM control on the switching of the transistors Q _{1 to} Q ₆ . The energization control unit 47 energizes each coil at the aforementioned timing. Thus, each coil has a reference clock signal corresponding to the target speed and the mover LMm.
Is applied so as to match the phase of the signal according to the actual moving speed. Thereby, the mover LMm can be driven at the target speed.

The linear motor LM1 and the drive control device 4A
The linear motor driving device of the present invention including the following has the following advantages. When driving the mover LMm in the right direction, the mover LM
Field magnet F at each position of P ₁ , P ₂ , and P ₃
The polarity of the magnetic pole of M is determined by encoder sensors ESa, ESb,
Encoder counter 44, magnetic pole detector 45, memory 46
In other words, the armature coil AC
Is detected without using a magnetic pole detection element such as a Hall element disposed near the armature, the magnetic pole can be detected almost without being affected by a magnetic field formed by energizing the armature coil AC. Therefore, the energization timing to each coil can be accurately detected, and the mover LMm
Can be accurately driven. In this example, between the encoder sensors ESa, ESb and the armature coil AC,
Since the yoke 31 made of a ferromagnetic material is arranged, the magnetic field formed by energizing the armature coil AC and the magnetic field formed by the field magnet FM are suppressed from acting on these encoder sensors. Therefore, the polarity of the magnetic pole can be accurately detected. Mover LM
The same applies when driving m in the left direction.

Further, when the field magnet FM is formed by magnetizing the guide shaft 1 (field magnet base) using the magnetizing device shown in FIG. 4, even if the width of each magnetic pole varies. The memory 46 stores the field magnet information including the variation of the magnetic pole width, and the memory 46 does not store the field magnet information for one period of the field magnet FM, Since the magnet information is stored, the energization timing to each coil can be detected with higher accuracy than before.

FIG. 9 shows that, when the magnetic field width of the field magnet fluctuates, the field magnet F
Based on the energization information for one cycle of M, the armature coil A
The timing of energizing each coil when energizing each coil of C is shown. FIG. 10 shows the timing of energizing each coil in the linear motor drive device of the present invention. 9 and 10, a hatched portion indicates that improper energization is performed. In the case of improper energization, the coil
When facing both poles of the pole, it means that the coil is energized. FIGS. 9 and 10 show the energization timing when the mover is driven rightward in FIG. 9 and 10, the magnetic poles at each position P _1, P ₂ and P ₃ indicates the relationship between the time. 9 and 1
At 0, the timing of energizing each coil indicates the relationship with the position in the longitudinal direction of the guide shaft.

In the linear motor driving device of the present invention, the energization timing to each coil is detected based on the field magnet information including the variation in the magnetic pole width of the field magnet FM. Can be reduced. As a result, thrust fluctuation can be suppressed. (2) Measurement of field magnet information (field magnet data) including variation information of the width of each magnetic pole of the field magnet FM stored in the memory 46 can be performed, for example, as follows.

Two adjacent coils L of the armature coil AC
_U1, L_V1In the “+” direction (the coil is
The coil generates a rightward thrust in Figure 1
Direction)), these coils will
11 (A) when it is located on the N pole and FIG.
As shown in FIG. 1 (B), any of
Even in the case, the coil L shown in FIG._U1Is N pole
Located on the coil L _V1Until these are on the S pole
The coil (movable element LMm) moves and stops at that position.
You. This stop position is determined by the coil L_U1And L_V1Each departure
The position where the raw thrust is balanced,
Is a position overlapping the boundary between the north pole and the south pole.

If currents of the same magnitude are applied to the coils L _U1 and L _V1 in the “−” direction (the direction in which the coils generate a leftward thrust in FIG. 1 when the coils are on the N pole), 1
The coil L _U1 shown in FIG. 1 (D) is located on the S pole and the coil L
These coils (movable element LM) are used until _V1 is located on the N pole.
m) moves and stops at that position. Therefore, if these properties are used, the switching position of the magnetic pole can be accurately detected without using a magnetic pole detecting element such as a Hall element.

The field magnet FM utilizing these properties
When measuring field magnet information for the entire length of
It can be done as follows. First, move the mover LMm to the home position.
Move to the option. This movement can be done manually, for example.
No. Thereby, the encoder of the encoder counter 44
Count value V _e(P₀) Is reset to “0”.
Encoder count value V_e(P₀) Is allowed as described above
Position P on the rotor LMm₀Of the guide shaft in the longitudinal direction
are doing.

In this example, when the mover LMm is located at the home position, the coils L _U1 and L _V1 are not
Since the coils are located on the N pole as shown in (A), if a current in the "+" direction is applied to these coils, these coils (movable element LMm) stop at the positions shown in FIG. 11C. This position is the position P ₂ on the movable element LMm is a position that is on the boundary of N and S poles. The encoder count value V _e (P ₀ ) at this stop position is defined as K ₁ . As described above, the memory 46 stores data indicating the polarity of the magnetic pole of the field magnet FM at the position P ₀ on the mover LMm. When the position P ₀ on the mover LMm is on the boundary between the N pole and the S pole, the encoder count value V _e (P ₀ ) becomes the count value K ₁ and the distance D between the position P ₀ and the position P ₂ . _The encoder count number _Ne (D ₂ ) corresponding to ₂ is added.
As a result, the encoder count value becomes 0 to ｛K ₁ + N
It can be seen that the polarity of the magnetic pole at each position of _e (D ₂ )｝ is the N pole. Therefore, the area for storing the polarity of the magnetic poles at each position of the encoder count value of the memory 46 is _{0~ {K 1 + N e (} D 2)}, the data (in this example showing the N pole,
"1") may be stored.

Next, after moving the mover LMm to the right by about one magnetic pole width M _W , if a current in the “−” direction is applied to the coils L _U1 and L _V1 , these move at the positions shown in FIG. The coil stops. The encoder count value V _e (P ₀ ) at this stop position is defined as K ₂ . Position P ₀ on mover LMm
N but encoder count V _e when is on the boundary of the S and N poles (P ₀₎ is the count value K _2
e (D ₂ ). Therefore, memory 4
6 encoder count value is ｛K ₁ + _Ne (D ₂ ) +
1} In the area for storing the polarity of the magnetic poles at each position _{~ {K 2 + N e (} D 2)}, the data (in this example showing the S pole,
"0") may be stored.

Hereinafter, similarly, field magnet information for the entire length of the field magnet FM can be measured.
In this way, if the field magnet information is detected, the field magnet information including the variation in the width of each magnetic pole of the field magnet FM can be accurately detected. (3) Since the drive control device 4A applies a pulse current to the armature coil AC of the linear motor LM1, the switching position of the magnetic pole of the field magnet FM in the longitudinal direction of the guide shaft and the N-pole to the S-pole at that position. If it is known whether the magnetic poles are switched at the position, or whether the magnetic poles are switched from the S pole to the N pole at that position, the linear motor LM1 can be driven. That is, the information indicating the magnitude of the magnetic field formed by the field magnet FM is not necessary when applying the pulse current. Therefore, even if the memory 46 stores, for example, field magnet information indicating the switching positions of the magnetic poles shown in the following FIGS. 12 and 13 instead of the field magnet information shown in FIG. LM1 can be pulsed.

The following information is stored in each memory area of the memory 46 shown in FIG. The address 0000 _H, when the mover LMm is located at the home position, the field magnet FM at the position P ₀ on the movable element LMm
The data indicating the polarity of the magnetic pole is stored. In this example, the north pole corresponds to the data “0001 _H ”, and the south pole corresponds to the data “0000 _H ”. Data at address 0000 _H of the memory 46 shown in FIG. 12, when the movable element LMm is located at the home position indicates that faces the N pole. Address 00
01 Each region after _H, when driving the movable element LMm from the home position to the right in FIG. 1, the position of the switching of the magnetic poles are sequentially stored. Each area of the address 0001 _H later, an encoder count value corresponding to the magnetic poles of the switching position is stored. That is, the address 0001 _H, when moving the movable element LMm from the home position to the right, the encoder count value indicating a magnetic pole is switched position from the N pole to the S pole is stored. The address 0002 _H, an encoder count value indicating a magnetic pole is switched located N pole from the S pole is stored.

The following information is stored in each memory area of the memory 46 shown in FIG. The address 0000 _H, when the mover LMm is located at the home position, the field magnet FM at the position P ₀ on the movable element LMm
The data indicating the polarity of the magnetic pole is stored. In this example, the north pole corresponds to the data “0001 _H ”, and the south pole corresponds to the data “0000 _H ”. The lower bits following the most significant bit of each area of the address 0001 _H later, similarly to the memory 46 of FIG. 12, the movable element L
When Mm is driven rightward in FIG. 1 from the home position, the encoder count value corresponding to the position at which the magnetic pole switches is stored in order. The most significant bit of each area of the address 0001 _H later, the mover LMm when driven from the home position to the right in FIG. 1, the N-pole or pole is switched to the S pole, or N pole from the S-pole Data indicating whether the magnetic pole is switched is stored. In this example, when the most significant bit is “1”, it indicates that the magnetic pole is switched from the N pole to the S pole. When the most significant bit is “0”, it indicates that the magnetic pole is switched from the S pole to the N pole. Therefore, for example, address 0001
_From the data of _H , when the mover LMm is being driven rightward in FIG. 1, the encoder count value is “012C”.
_When " _H " is reached, it can be seen that the magnetic pole switches from the N pole to the S pole. Further, when driving the mover LMm to the left in Figure 1, from the data of the address 0001 _H, when the encoder count value becomes "012C _H", the magnetic poles are switched from S pole to N pole I understand. (4) The method of flowing currents in the same direction to two adjacent coils of the armature coil AC can also be used when returning the mover LMm to the origin (when moving the mover LMm to the home position). .

Immediately after turning on the power of the linear motor driving device,
Is at which position of the mover LMm in the longitudinal direction of the guide shaft
Is the encoder count value of the encoder counter 44
I do not know from. Therefore, first, next to the armature coil AC
A current of the same direction is applied to two matching coils. For example,
Il L_U1And L_V1If a current in the “+” direction is passed through the
_U1Is located on the N pole and the coil L_V1Is located on the S pole
Stop at the position (magnetic pole switching position). Turn off this pole
Where is the switching position in the longitudinal direction of the guide shaft
I do not know. However, the switching position of adjacent magnetic poles is
Bo M_WBecause it is a distant position, for example, when returning to origin
Is read from the memory 46 from the magnetic pole detector 45.
Field magnet information instead of
Output information to the energization control unit 47,
To each coil of the slave coil AC at the same timing as described above.
When electrified, the mover LMm is driven to the left in FIG.
The point can be returned.

[0094] From the magnetic pole detection section 45, as the field magnet information at the position P ₂ on the movable element LMM, the coil L _U1 and L _V1 by passing a "+" direction of the current, at a position where the coils stops to output a polarity signal indicating the N-pole, it is sufficient to output by switching the polarity signal each time a subsequent mover LMm is M _W moves leftward. As the field magnet information at the position P ₃ on the movable piece LMM, by applying a current of the coil L _U1 and "+" direction L _V1, to output a polarity signal indicating the S pole at the position to which they coil stops, switching the polarity signal mover LMm indicates N pole When M _W / 3 moves to the left, it is sufficient to output by switching the polarity signal each time a subsequent mover LMm is M _W moves leftward. Mover LMm
As the field magnet information at the position P ₄ of the above, the coil L
Flowing a "+" direction of the current in _U1 and L _V1, the position where the coils stops to output the polarity signal indicating the S pole, polarity mover LMm indicates N pole Once 2M _W / 3 moves leftward switching the signal, it is sufficient to output by switching the polarity signal each time a subsequent mover LMm is M _W moves leftward.

[0095] Alternatively, by applying a current of "+" direction in the coil L _U1 and L _V1, the position where the coils stops, the boundary of the coil L _U1 and L _V1 is the rightmost field magnet FM N poles and S Assuming that the position overlaps the boundary between the magnetic poles of the poles, the origin return can be performed as follows. The coil L _U1 and L _V1 by passing a "+" direction of the current, at a position where the coils stops, the boundary of the magnetic poles of the right end of the N and S poles of the boundary of the coil L _U1 and L _V1 is field magnet FM The encoder count value corresponding to the position overlapping
Preset to. Then, in the same manner as described above, the magnetic pole detection unit 45 reads out field magnet information from the memory 46 based on the encoder count value from the encoder counter 44, and moves the mover LMm to the left based on the field magnet information. What is necessary is just to energize each coil.

In any case, when performing the home return in this way, the energization timing to each coil is detected based on accurate field magnet information.
Although the thrust fluctuation is slightly large, there is no problem because it is only when returning to the home position. (5) Instead of the drive control device 4A shown in FIG. 3, FIG.
If the drive control device 4B shown in FIG.
M1 can be driven linearly. Linear motor LM
1 and the drive control device 4B provide a linear motor drive device according to the present invention.

When linearly energizing each phase coil of the armature coil AC, each phase coil of the armature coil AC is connected as shown in FIG. U-phase coil L _U1 , L _U2
And L _U3 are connected in parallel. The coil L _U2 is wound around the stator LMs in the opposite direction to the coils L _U1 and L _U3 . The V-phase coils L _V1 , L _V2 and L _V3 are connected in parallel. Coil L _V2 is _equal to coils L _V1 and L _V3
And wound around the stator LMs in the opposite direction. In the W-phase coil, L _W1 , L _W2 and L _W3 are connected in parallel. The coil L _W2 is wound around the stator LMs in the opposite direction to the coils L _W1 and L _W3 .

The drive control device 4B operates such that a current proportional to the magnitude and direction of the magnetic field formed by the field magnet FM at the center position of each coil in the guide shaft longitudinal direction (stator longitudinal direction) flows through the coil. Then, energize each coil,
The mover LMm is driven. The drive control device 4B can also perform PLL control on the linear motor LM1 similarly to the drive control device 4A.

The drive control unit 4B includes a drive command unit 41, P
LL control section 42, compensation circuit section 43, encoder counter 44, magnetic pole detection section 45, memory 46, U phase, V phase and W
Phase coil energization control units 47U, 47V, 47W and U
Phase, V phase and W phase coil energizing circuits 48U, 48V, 48
W is provided. A drive command unit 41 of the drive control device 4B,
The PLL control unit 42, the compensation circuit unit 43, and the encoder counter 44 perform the same operations as those of the drive control device 4A.

The memory 46 stores field magnet information indicating the magnitude and direction of the magnetic field formed by the field magnet FM at each position in the longitudinal direction of the guide shaft.
The memory 46 stores field magnet information for the entire length of the field magnet FM. The field magnet information is measured in advance and stored in the memory 46. The field magnet information stored in the memory 46 is field magnet information including a variation in each magnetic pole width of the field magnet FM.

In this example, the memory 46 is an 8-bit memory as shown in FIG. The memory 46 stores the field magnet FM at the position P ₀ on the mover LMm by associating the encoder count value with the memory address as follows.
The data indicating the magnitude and the direction of the magnetic field formed by is stored. The field magnet data at the position of the encoder count value V _e (P ₀ ) = K is stored in the area of the address K. For example, encoder count value V
_e at the position of (P ₀₎ = _0, the field magnet data is stored in the address 0000 _H. The most significant bit of the field magnet data stored at each address indicates the direction of the magnetic field (polarity of the magnetic pole). In this example, the north pole corresponds to data "0", and the south pole corresponds to data "1".
It corresponds to. Data indicating the magnitude of the magnetic field is stored in the lower 7 bits.

In the drive control device 4A shown in FIG. 3, field magnet data indicating the magnitude and direction of such a magnetic field is stored in the memory 46, and the magnetic pole detection section 45 determines the predetermined position from the data. May be detected. The magnetic pole detection unit 45 includes the encoder counter 4
4, the data indicating the polarity of the magnetic pole of the field magnet FM at the next three positions on the mover LMm is read from the memory 46 based on the encoder count value input from the memory 4, and the data is read out from each of the phase energization controllers 47U, 47V, Output to 47W.

The magnetic pole detector 45 reads out the field magnet data from the memory 46 at the center position of the U-phase coil L _U1 , V-phase coil L _V1 , and W-phase coil L _{W1 in} the longitudinal direction of the guide shaft. The field magnet data at the center position of the U-phase coil L _U1 read by the magnetic pole detection unit 45 is converted into an analog signal by the D / A converter 49U, and then input to the U-phase coil conduction control unit 47U. .

The U-phase coil energization control unit 47U further receives a drive direction signal from the drive command unit 41 and receives a drive signal according to a phase difference between a reference clock signal corresponding to the target speed and an encoder signal indicating the actual moving speed. The signal which has been subjected to lead / lag compensation of the transmission system is input from the compensation circuit unit 43. The U-phase coil energization control unit 47U
Based on the signals input from the magnetic pole detection unit 45 via the D / A converter 49U, a current proportional to the magnitude of the magnetic field acting on the coil L _U1 via a current supply circuit 48U U-phase coil L _U1, L Energize _U2 and _LU3 . Energization control unit 47
U depends on the direction of the magnetic field acting on the coil L _U1 ,
The direction of the current that generates thrust in the direction indicated by the drive direction signal via the current supply circuit 48U energizing the U-phase coil L _U1, L _U2 and L _U3. The energization control unit 47U
A current corresponding to the signal input from the compensation circuit unit 43 is supplied to the U-phase coils L _U1 , L _U2, and L _U3 via the conduction circuit 48U.

Similarly, the V-phase coil energization control unit 47V and the energization circuit 48V energize the V-phase coils L _V1 , L _V2 and L _V3 . W-phase coil conduction control unit 47W, conduction circuit 48W
Energizes the W-phase coils L _W1 , L _W2 and L _W3 . As a result, the coils are energized so that the phases of the reference clock signal corresponding to the target speed and the signal corresponding to the actual moving speed of the mover LMm are matched. Thereby, the mover L
Mm can be driven at the target speed.

As described above, even when the linear motor LM1 is linearly driven by the drive control device 4B, there is an advantage similar to that when the linear motor LM1 is pulse-driven by the drive control device 4A. The magnetic field formed by the field magnet FM can be detected almost without being affected by the magnetic field formed by energizing the armature coil AC. Therefore, the linear motor LM1 can be driven with higher accuracy.

Further, even if the width of the magnetic pole of the field magnet FM varies, the torque ripple can be suppressed and the linear motor LM1 can be driven more accurately than before. (6) When data indicating the magnitude of the magnetic field of the field magnet is stored in the memory 46, the field magnet information at a position not stored in the memory 46 is stored in the memory 46.
Can be obtained by interpolation from the field magnet information at the positions before and after that stored in the. When performing such interpolation, the number of data stored in the memory 46 can be reduced. For example, the memory 46 may store field magnet information at each position where the encoder count value is 10 · J (J is an integer). That much memory 46
A small storage capacity can be used.

When a part of the magnitude of the magnetic field formed by the field magnet FM at each position in the longitudinal direction of the guide shaft is obtained by interpolation, the obtained magnetic field distribution in the longitudinal direction of the guide shaft becomes smooth. When detecting a magnetic field with a magnetic sensor such as a Hall element, the resulting magnetic field distribution in the longitudinal direction of the guide shaft may have small vibrations due to the effects of noise, etc. In the case of linear drive calculated by
Thus, the linear motor can be driven with high accuracy. The output signal of the D / A converter may be subjected to smoothing (filtering) to smooth the obtained magnetic field distribution.

At the time of pulse driving, as shown in FIG. 16, the output signal indicating the field magnet information read from the memory is filtered so that the switching position of the magnetic pole is emphasized, and the switching position of the magnetic pole is determined. May be. In this way, the switching position of the magnetic pole can be detected with high accuracy even when the resolution of the data indicating the magnitude of the magnetic field stored in the memory is low. (7) FIG. 17 shows a schematic side view of the linear motor LM3 according to the present invention.

The linear motor LM3 has a guide shaft 1 extending linearly in a predetermined direction. The guide shaft 1 is made of a magnetic material and is magnetized as described later. The guide shaft 1 is made of Mn-Al in this example. The guide shaft 1 is
N-poles and S-poles are magnetized so as to be alternately arranged in the longitudinal direction of the guide shaft, whereby a field magnet FM is formed on the guide shaft 1. The guide shaft 1 is magnetized such that one magnetic pole width of the field magnet FM is M _W.

The guide shaft 1 on which the field magnet FM is formed constitutes a stator LMs of the linear motor LM1. A movable element LMm that reciprocates along the guide shaft 1 is fitted to the stator LMs. The mover LMm includes an armature coil AC, a yoke 31, and bearings 321 and 322.
And can reciprocate along the stator LMs (guide shaft 1). The armature coil AC is composed of three coil groups each including three coils of the U, V, and W phases having the same structure and configuration as the above-described armature coil of the linear motor LM1.

The linear motor LM3 is a magnet scale MS arranged in parallel with the guide shaft 1 (stator LMs).
have. The magnet scale MS extends in the longitudinal direction of the guide shaft. In this example, the magnet scale MS is formed by magnetizing a plate-shaped magnet scale base MSb made of a magnetic material. The magnet scale base MSb has the same length as the guide shaft 1 (field magnet base). The scale base MSb is made of the same Mn-Al as the guide shaft 1 in this example. The magnet scale MS has N magnetic poles and S magnetic poles arranged alternately. Each N pole of the magnet scale MS faces each N pole of the field magnet. Each S pole of the magnet scale MS faces each S pole of the field magnet.

The magnet scale MS is formed by magnetizing the scale base MSb simultaneously with the guide shaft 1 (field magnet base) using the magnetizing device shown in FIG. is there. FIG. 18 (A) and (B)
As shown in (1), the guide shaft 1 (field magnet base) and the magnet scale base MSb are arranged inside the hollow of the pipe 81 and magnetized. The guide shaft 1 and the magnet scale base MSb are arranged inside the pipe 81 in parallel with, close to or in contact with each other. After arranging the guide shaft 1 and the magnet scale base MSb in the pipe 81 in this manner, the magnetizing coils 821, 822, 823, 824,.
By applying a high voltage so that a current flows in a direction opposite to that of the adjacent coil, a field magnet FM can be formed on the guide shaft 1. Also, the magnet scale M
S can be formed.

The magnetization of the magnet scale base MSb and the field magnet base (guide shaft 1) may be performed as follows. A sealing material is pasted on the magnet scale substrate MSb, and at the time of magnetization, the magnet scale substrate MSb is pasted (temporarily attached) to the field magnet substrate (guide shaft 1) using the sealing material. In this state, magnetization may be performed in the same manner as described above. After the magnetization is completed, the magnet scale base MSb and the guide shaft 1 on which the field magnet is formed are separated, and the scale base MSb on which the magnet scale MS is formed is separated from the guide base 1 using a sealing material to a predetermined position such as an apparatus frame. It may be attached to the position. As a result, the arrangement of the magnet scale MS becomes easier.

Since the magnet scale base MSb and the guide shaft 1 (field magnet base) were simultaneously magnetized using the same magnetizing device, the magnetic field (magnitude and magnitude) at each position in the longitudinal direction of the guide shaft formed by the magnet scale MS was determined. direction)
Is proportional to the magnetic field at each position in the longitudinal direction of the guide shaft formed by the field magnet FM as shown in FIG. Accordingly, the position where the magnitude of the magnetic field formed by the magnet scale MS is 0, in other words, the switching position of the magnetic pole of the magnetic field formed by the magnet scale MS is the same as the switching position of the magnetic pole of the magnetic field formed by the field magnet. At the same position in the longitudinal direction of the guide shaft. That is, the width of each magnetic pole of the magnet scale MS is the same as the width of the corresponding magnetic pole of the field magnet FM. Therefore, the field magnet F may be changed due to an error in the width of the magnetizing coil.
The width of each magnetic pole of M is not varied for a given width M _W, to the width of the magnetic poles of the magnet scale MS opposing the magnetic poles of the field magnet FM equal to the width of the magnetic poles of the field magnet FM Can be.

In the linear motor LM3, the mover L
Mm, the position P described in the linear motor LM1.
₁, P_Two, P_ThreeAt each position as a magnetic sensor
Element h₁, H_Two, H_ThreeIs arranged. Sand
And the Hall element h₁Is the coil L_U1Guide shaft longitudinal direction
From the center position in FIG. 17 to the left in FIG._W/ 6 shifted
Is located in the position. Hall element h_TwoIs the coil L_V1
17 from the center position in the longitudinal direction of the guide shaft to the left in FIG.
Toward M_W/ 6. Hall element
h_ThreeIs the coil L_W1Center position in the longitudinal direction of the guide shaft
From the position to the left in FIG._W/ 6
ing. These Hall elements h₁, H_Two, H _ThreeEach
And is arranged on the outer peripheral surface of the mover yoke 31.
We are facing a multi-scale MS.

The linear motor LM3 is also a linear motor LM.
As in the first embodiment, a linear encoder including an encoder chart Ec and encoder sensors ESa and ESb is provided. FIG. 20 is a schematic block diagram of a drive control device 4C according to the present invention that drives and controls the linear motor LM3. The linear motor drive device according to the present invention is provided by the linear motor LM3 and the drive control device 4C.

The drive control device 4C can pulse drive the linear motor LM3, similarly to the drive control device 4A shown in FIG. The drive control device 4C includes the drive control device 4C.
Encoder counter 44 A, is obtained by replacing the magnetic pole detection unit 45 and the memory 46 to the Hall element _{h 1, h 2, h 3} . For other parts, the drive control devices 4C and 4A
Are substantially the same.

The field magnet information at each position of P ₁ , P ₂ , and P ₃ on the mover LMm detected by the encoder counter 44, the magnetic pole detection unit 45, the memory 46, and the like in the drive control unit 4A is based on the drive control. In the device 4C, the Hall elements h ₁ , h ₂ , h arranged at these respective positions
Detected by _three . The magnetic field formed by the magnet scale MS facing the Hall elements h ₁ , h ₂ and h ₃ is proportional to the magnetic field formed by the field magnet FM as described above.
It is possible to detect ₁ to P ₃ of the polarity of the magnetic field poles field magnet FM forms at each position (direction of the magnetic field).

The field magnet information detected by the Hall elements h ₁ , h ₂ , h ₃ is input to the energization control unit 47. Also in the drive control device 4C, similarly to the drive control device 4A, the linear motor LM3 can be PLL-controlled to drive the mover LMm to move at the target speed. Mover LMm linear motors LM3, based on the field magnet information position on the mover P _1, P _2, Hall elements h ₁ which are disposed in P _3, h _2, h ₃ is detected, the above-described FIG. By energizing each coil at the same timing as the timing shown in FIG. 7, it is possible to drive in the right direction in FIG. When the mover LMm is driven to the left in FIG. 17, the coils are energized at the same timing as that shown in FIG. 8 based on the field magnet information detected by the Hall elements h ₁ , h ₂ , and h ₃ . May be. If reversing the polarity of the magnetic poles detected by the Hall elements h _1, the polarity of the magnetic pole at the position P ₄ on substantially the mover. Alternatively, the position P ₄ on the movable piece, by placing a Hall element h ₄ so as to face the magnetic scale MS, Hall element h _2,
Based on the magnetic poles detected by h ₃ and h ₄ , the coils may be energized at the same timing as that shown in FIG. 8 to drive the mover LMm to the left.

Between the Hall elements h ₁ , h ₂ , h ₃ for detecting field magnet information and the armature coil AC,
Since the yoke 31 made of a ferromagnetic material is provided, it is possible to suppress the effect of the magnetic field formed by energizing the armature coil AC on these Hall elements. In the linear motor LM3, the yoke 31 also functions as a magnetic shield member for preventing the magnetic field formed by the armature coil AC from acting on the Hall element. Therefore, it is possible to accurately detect the energization timing of each coil by these Hall elements, and to drive the linear motor LM3 with high accuracy. Further, since these Hall elements are arranged close to the magnet scale MS, these Hall elements can detect field magnet information more accurately.

The magnet scale MS controls the driving of the linear motor LM1 even if the magnetic pole widths of the field magnet FM vary, as described above, because the magnetic poles of the field magnet FM have the same variation. Similarly to the case where the drive control is performed by the device 4A, in the linear motor drive device including the linear motor LM3 and the drive control device 4C, the energization timing to each coil can be detected with higher accuracy than in the past, and the rate of improper energization is reduced as compared with the conventional case. be able to. The thrust fluctuation can be suppressed accordingly.

For the magnet scale base for forming the magnet scale, a magnetic recording material such as a magnetic tape for recording music, for example, may be used.
When a magnetic recording material is used as the magnet scale substrate, a magnet scale can be formed on the magnetic recording material only by bringing the magnetic recording material into contact with or near the guide shaft 1 on which the field magnet FM is formed.
Since the magnetic field of the field magnet FM is copied to the magnetic recording material, the magnetic field formed by the magnet scale formed on the magnetic recording material also changes at each position in the longitudinal direction of the guide shaft. Is proportional to When the magnetic recording material is used in this manner, it is not necessary to magnetize the magnet scale base simultaneously with the field magnet base using a magnetizing device, and the magnet scale can be formed more easily. (8) FIG. 21 shows a schematic side view of the linear motor LM4 according to the present invention. FIG. 22 is a schematic block diagram of a drive control device 4D according to the present invention for controlling the drive of the linear motor LM4.
Shown in The linear motor LM4 and the drive control device 4D provide a linear motor drive device according to the present invention.

The linear motor LM4 is substantially the same as the linear motor LM1 shown in FIG. 1 except that three Hall elements are arranged at the following positions. In the linear motor LM4 are Hall elements h ₁ to the position of the position P _1, P _2, P ₃ mentioned in the linear motor LM1 on the mover LMM, h _2, h ₃ are arranged.
That is, the Hall element h ₁ is, M _W / 6 from the central position to the left in FIG. 21 in the guide shaft longitudinal direction of the coil L _U1
It is located at a shifted position. Hall element h ₂ is a view from the center position in the guide shaft longitudinal direction of the coil L _V1 21
It is arranged at a position shifted by M _W / 6 in the middle left direction. Hall element h ₃ is disposed at a position shifted M _W / 6 from the central position in the guide shaft longitudinal direction of the coil L _W1 to the left in FIG. These Hall elements h ₁ , h ₂ , h ₃ are:
It is arranged on the outer peripheral surface of the armature coil AC, and faces the field magnet FM.

The drive control device 4D includes a linear motor LM4
Is pulsed. Drive control unit 4D is for the magnetic pole detection unit 45 and the memory 46 of the drive control device 4A shown in FIG. 3, replaced with Hall elements h _1, h _2, h ₃ and the magnetic pole correction unit 51. For other parts, the drive control device 4
D and 4A are substantially the same.

The field magnet information at each of the positions P ₁ , P ₂ , and P ₃ on the mover LMm detected by the encoder counter 44, the magnetic pole detection unit 45, the memory 46, and the like in the drive control unit 4A is based on the drive control. In the device 4D, the Hall elements h ₁ , h ₂ , h arranged at each of these positions
₃ , detected by the encoder counter 44 and the magnetic pole correction unit 51 as follows.

As described in the description of the prior art, when the armature coil AC is energized to move the mover LMm, the mover LMm is disposed at each of the positions P ₁ , P ₂ , and P ₃ on the mover LMm. The magnetic field of the field magnet FM detected by the Hall elements h ₁ , h ₂ and h ₃ is distorted by the magnetic field formed by the armature coil AC as shown in FIG. Due to the magnetic field formed by the armature coil AC, the Hall element cannot detect the accurate switching position of the magnetic pole of the magnetic field formed by the field magnet FM. Therefore, from the magnetic field signals detected by the Hall elements h ₁ , h ₂ , h ₃ , the energization timing of each coil cannot be correctly detected, and the detection signals of these Hall elements were directly input to the energization control unit 47. Then, the thrust ripple becomes large.

Therefore, in the drive control device 4D, the magnetic
The pole corrector 51 is a Hall element h₁, H _Two, H_ThreeDetection magnetic field
Are corrected using the encoders as follows.
The corrected signal is referred to as P on the mover LMm.₁, P_Two, P
_ThreeField indicating the magnetic field formed by the field magnet at each position
The information is input to the power supply controller 47 as magnetic magnet information.

As shown in FIG. 23, the switching position of the magnetic pole detected by the Hall element h ₁ is shifted from the actual switching position of the magnetic pole of the magnetic field formed by the field magnet FM at the position P ₁ on the mover. The child LMm is a distance D _{EC in the} driving direction.
Detected at advanced position. This is shown in FIG.
The same applies when driving in either the left or right direction during one.
Distance D _EC between the actual magnetic pole switching position of the field magnet FM, switching of the magnetic poles detected by the Hall element h ₁ position at the position P ₁ on the movable element is determined by such coil energization amount. If the coil current amount is constant, the distance D _EC of the switching position of the field magnet FM magnetic pole at the position P ₁ on the movable element, the switching position of the corresponding magnetic pole detected by the Hall element h ₁ is a constant Become.

Therefore, if the magnetic pole width of the field magnet FM is M _W , the position where the mover LMm has advanced (M _W -D _EC ) from the magnetic pole switching position detected by the Hall element h ₁ is the position above the mover. the switching position of the next pole of the magnetic field field magnet FM forms at the position P _1. Similarly,
Mover LMm from the magnetic pole switching position Hall element h ₂ is detected (M _W -D _EC) advanced position, switches the next pole of the magnetic field field magnet FM at the position P ₂ on the movable element is formed Position. Mover LMm from the magnetic pole switching position of Hall element h ₃ was detected (M _W -D _EC)
Advanced position, the switching position of the next pole of the magnetic field field magnet FM forms at the position P ₃ on the movable element.

[0131] In magnetic pole correction unit 51 utilizes the encoder count value input from the encoder counter 44, a magnetic pole switching position detected Hall elements h _1, armature LMm is a distance (M _W -D _EC) When the advanced corresponding number of encoder counts, switching the magnetic poles on switching the opposite pole of the Hall element h ₁ has detected. The switch the magnetic poles reversed, for example, when the Hall element h ₁ detects the switching of the pole to the S pole from N-pole refers to switching the magnetic poles from the S pole to the N pole. The signal obtained by correcting the detection signal of the Hall element h _{1 in} this manner is used as field magnet information at the position P ₁ on the mover as the energization control unit 4.
Enter 7 Similarly, the corrected signal detection signal of the Hall element h _2, as the field magnet information at the position P ₂ on the movable element, is input to the power supply controller 47. Hall element h
The corrected signal ₃ of the detection signal, as the field magnet information at the position P ₃ on the movable piece, and inputs to the power supply controller 47.

The energization control unit 47 detects the energization timing of each coil based on the field magnet information at each of the positions P ₁ , P ₂ , and P ₃ input from the magnetic pole correction unit 51, and Is energized as described above. By energizing each coil at the same timing as the timing shown in FIG. 7, the mover LMm can be driven rightward in FIG. When the mover LMm is driven to the left in FIG. 21, the positions P ₁ , P
Based on the field magnet information at each position of the _2, P _3, may be energized to each coil at the same timing as the timing shown in Figure 8 above. If reversing the polarity of the magnetic pole at the position P ₁ that is input from the magnetic pole correction unit 51, the polarity of the magnetic pole at the position P ₄ on substantially the mover. Alternatively, a Hall element h ₄ is further arranged at the position P ₄ on the mover, and the Hall element h ₄
Based on the polarity of the magnetic _{pole 2,} h _3, h ₄ is detected by performing the same way as described above for correcting the magnetic pole correction unit 51 detects a magnetic pole at each position of the position _{P 2, P 3, P 4} , FIG. The coils may be energized at the same timing as that shown in FIG. 8 to drive the mover LMm to the left.

By correcting the detection magnetic poles of the Hall elements in this manner, the electric power supply timing is detected without any correction based on the detection signal of each Hall element and the electric current is supplied to each coil. The influence of the magnetic field formed by the child coil AC can be suppressed, the energization timing can be detected accurately, and the mover LMm can be driven with less thrust variation.

As described above, the distance D _EC between the actual magnetic pole switching position of the magnetic field formed by the field magnet FM and the corresponding magnetic pole switching position detected by the Hall element.
Varies with the amount of coil current. The distance D _EC is increased substantially in proportion to the coil current amount. Therefore, if the magnetic pole correction unit 51 also changes the distance _DEC based on the coil energization amount, the energization timing of each coil can be detected with higher accuracy. Information indicating the coil energization amount is
For example, it can be obtained from the power supply control unit 47. A current sensor may be provided for the armature coil AC, and information indicating the amount of current may be directly obtained from the current sensor. (9) The linear motor LM4 shown in FIG. 21 can be pulse-driven as follows using the drive control device 4D shown in FIG.

On the mover LMm of the linear motor LM4
Is the position P₁, P_Two, P_Three, P _FourIt in each position
Each is a Hall element h₁, H_Two, H_Three, H_FourPlace
Good. When the mover LMm is driven, for example, rightward in FIG.
The position P₁, P_Two, P_ThreeEach position
Based on the magnetic pole of the magnetic field formed by the field magnet FM
The drive control device 4D is configured to control each coil of the armature coil AC.
Detects the timing of energization of the coil and applies a pulse to each coil
I do.

In the example described above, the positions P ₁ , P ₂ , P ₃
Are detected by correcting the detected magnetic poles of the Hall elements h ₁ , h ₂ , and h ₃ arranged at each position by the magnetic pole correction unit 51. In this example, the positions P ₁ , P ₂ , P
Polarity of the magnetic poles at each position of _3, each driving direction from the position (in this example, right direction) Hall element h ₂ arranged in a position advanced M _W / 3 in, h _3, h ₄ is detected Magnetic poles,
It is detected by the magnetic pole correction unit 51 correcting as follows.

The magnetic pole correction unit 51 corrects the detection magnetic pole of the Hall element h ₂ arranged at the position P ₂ as follows, so that the magnetic field generated by the field magnet FM at the position P ₁ on the mover is obtained. Is detected. The correction method will be described with reference to FIG. The position P ₁ to be detected the magnetic poles of the field magnet FM, the distance D _EA between position P ₂ where the Hall element h ₂ is disposed, so in this example is M _W / 3, is a Hall element h ₂ position if to accurately detect the magnetic field field magnet FM forms at P _2, by correcting the deviation of the placement distance difference D _EA amount corresponding phase, it is possible to detect the polarity of the magnetic pole at the position P ₁ .

However, when the armature coil AC is energized,
When driving the mover LMm rightward in FIG. 21, the magnetic poles of the switching position of the magnetic field field magnet is formed at the position P ₂ of the Hall element h ₂ are disposed, the magnetic field detected by the Hall element h ₂ switching position of the corresponding magnetic pole (in this example, right direction) distance D _EC only driving direction becomes a position advanced to.

Therefore, after all, the Hall element h
The error distance D _E between the switching position of the magnetic pole detected by ₂ and the switching position of the corresponding magnetic pole of the magnetic field formed by the field magnet FM at the position P ₁ on the mover is D _E = D
The _EA -D _EC. After Hall element h ₂ detects the switching of the magnetic poles, it switched corresponding magnetic pole at the position P _1. Therefore, the magnetic pole correction unit 51 sets the error distance D _E = D _EA after the Hall element h ₂ detects the switching of the magnetic pole.
-D _EC only position advanced to the movable element LMm driving direction, by performing a similar correction to switch the pole and switching of magnetic pole Hall element h ₂ has detected the formation of the field magnet FM at position P ₁ field Can be detected. When such to correct, even if there are variations in the width of each magnetic pole of the field magnet FM, you are possible to detect the polarity of the magnetic pole at exactly the position P _1.

If the detected magnetic poles of the Hall elements h ₃ and h ₄ are similarly corrected by the magnetic pole corrector 51, the polarities of the magnetic poles of the field magnet FM at the respective positions P ₂ and P ₃ are detected. be able to. When the mover LMm is driven to the left in FIG. 21, the detection magnetic poles of the Hall elements h ₁ , h ₂ and h ₃ arranged at the positions P ₁ , P ₂ and P ₃ are similarly corrected. The magnetic pole at each of the positions P ₂ , P ₃ , and P ₄ may be detected, the energization timing for each coil may be detected, and the current may be energized to each coil. (10) FIG. 25 shows a schematic side view of the linear motor LM5 according to the present invention.

The linear motor LM5 is substantially the same as the linear motor LM4, except that the positions of the three hall elements h ₁ , h ₂ and h ₃ of the linear motor LM 4 shown in FIG. 21 are changed. . The linear motor LM5 can also be pulse-driven by using the drive control device 4D shown in FIG. 22 described above and changing the correction by the magnetic pole correction unit 51 as follows. The linear motor drive device according to the present invention is provided by the linear motor LM5 and the drive control device 4D.

[0142] In the linear motor LM5 the Hall element h ₁ is arranged in a central position in the guide shaft longitudinal direction of the coil L _U1. Hall element h _2, a coil L _V1
Are arranged at the center position in the longitudinal direction of the guide shaft. Hall element h ₃ is disposed at the center position in the guide shaft longitudinal direction of the coil L _W1. These Hall elements face the field magnet FM.

The Hall element has directivity in the direction of the magnetic field that can be detected. The Hall element hardly detects a magnetic field in a direction orthogonal to the magnetic field in a direction detectable by the Hall element. Field magnet FM formed on guide shaft 1
Forms a radial magnetic field in a cross section perpendicular to the longitudinal direction of the guide shaft as shown in FIG. Each of the Hall elements is a magnetic field formed by the field magnet FM.
5 so that the magnetic field in the vertical direction can be detected. Each Hall element is arranged so as to be able to detect a magnetic field in a direction that generates an electromagnetic force in the longitudinal direction of the guide shaft when the armature coil is energized. Accordingly, the magnetic field in the left-right direction in FIG. 25 is hardly detected by each Hall element. Coil L
_Magnetic fields _U1 is formed by energization, in the position where the Hall element h ₁ is located, because it is the magnetic field in the horizontal direction of the orientation in FIG. 25, the Hall element h ₁ is the influence of the magnetic field coil L _U1 is formed by energization , The direction of the magnetic field formed by the field magnet FM can be detected.

[0144] detection magnetic field of the Hall element h ₁ is as shown in Figure 27, the aforementioned FIG. 23, not distorted as shown in FIG. 24. Also, switching position of the magnetic poles of the magnetic field detected by the Hall element h ₁ is the same as the corresponding pole of the switching position of the magnetic field field magnet FM forms at the position where the Hall element h ₁ is disposed. Therefore, the linear motor L
In M5, when driving the mover LMm rightward in FIG. 25, the switching position of the magnetic poles of the magnetic field field magnet FM at the position P ₁ on the movable element is formed, the Hall element h ₁ detects the magnetic field the error distance D _E of the switching position of the corresponding magnetic poles, the distance D _EA = M _W / 6 of the arrangement positions of P ₁ and Hall elements h _1. Further, after the Hall element h ₁ detects the switching of the magnetic poles, it switched corresponding magnetic poles of the magnetic field formed by the field magnet FM at position P _1.

Thus, the magnetic pole correction section 51 is
When the LMm is driven rightward in FIG.
Child h₁Has detected the switching of the magnetic pole, the error distance D
_E= D_EA= M_WThe mover LMm advances in the drive direction by / 6
In the position, the Hall element h₁Switching of magnetic pole detected by
If the correction for switching the magnetic poles is performed in the same manner as ₁
Can detect the forming magnetic field of the field magnet FM
Wear. The width of each magnetic pole of the field magnet FM varies.
Even exactly, position P₁The polarity of the magnetic pole at
Can be.

When the mover LMm is driven rightward in FIG. 25, if the detected magnetic poles of the Hall elements h ₂ and h ₃ are similarly corrected by the magnetic pole correction unit 51, the positions P ₂ and P ₃
, The polarity of the magnetic pole of the field magnet FM at each position can be accurately detected. Therefore, the linear motor LM
5 and the linear motor drive device including the drive control device 4D, the influence of the magnetic field formed by the armature coil AC can be suppressed, the energization timing can be accurately detected, and the mover LMm can be driven with less thrust fluctuation. it can.

Also, the width of each magnetic pole of the field magnet FM is
Even if there is fluctuation, the above-described linear motor LM1 is
As in the case of controlling the drive by the control device 4A,
Can be suppressed more than before. It is possible to suppress thrust fluctuation
The moving element LMm can be driven. Linear motor LM
When driving the mover LMm 5 in the left direction in FIG.
Is the Hall element h₁, H_Two, H_ThreeDetection magnetic field
To the position P_Two, P_Three, P _FourMagnetic poles at each position
To detect the energization timing of each coil, and
What is necessary is just to energize each coil by imaging. (11) FIG. 28 shows a linear motor LM6 according to the present invention.
FIG. 2 shows a schematic side view.

[0148] Linear motors LM6, instead of the three Hall elements h _1, h _2, h ₃ of the linear motor LM4 shown in FIG. 21, except in that a six Hall element to the next position, the linear motor It is substantially the same as LM4. The linear motor LM6 can be pulse-driven using the drive control device 4E shown in FIG. The linear motor LM6 and the drive control device 4E provide a linear motor drive device according to the present invention.

As described with reference to FIG.
Depending on the position where the Hall element is arranged, the magnetic field detected by the Hall element when energizing and driving the armature coil AC through the armature coil AC causes the field magnet FM to be formed by the magnetic field formed by the energization of the armature coil AC. To the applied magnetic field. The switching position of the magnetic pole detected by the Hall element by the magnetic field formed by the armature coil AC is:
From the corresponding magnetic poles of the switching position of the field magnet FM at the position where the Hall elements are arranged, the distance D _EC displaced position. From switching position of the magnetic poles of the field magnet FM at the position where the Hall elements are arranged at a position where the mover LMm advances distance D _EC, the Hall element detects the switching of the corresponding pole.

Then, in the linear motor LM6,
In case of detecting the energization timing to the coil of the armature coils AC, in order to correct the deviation of the distance D _EC content of magnetic pole switching position of the phase, from the position to be detected polarity of the magnetic poles of the mover, drive direction Hall elements at a distance D _EC advanced position (direction to drive the movable element LMM) is disposed.

When the mover LMm is driven in the right direction in FIG. 28, the energization timing to each coil of the armature coil AC is determined by the positions P ₁ , P ₂ , P on the mover in this example.
Detected based on the polarity of the magnetic pole at each position of ₃ . In order to detect the polarity of the magnetic pole at each of these positions, in the linear motor LM6, three Hall elements h _1R ,
h _2R and h _3R are arranged.

Hall element h_1RIs the position on the mover LMm
P₁To the right in FIG. 28 (moving the mover LMm to the right
Distance D in the driving direction when_ECIs located in a shifted position
ing. Hall element h_2RIs the position P on the mover LMm._Two
28 to the right in FIG. 28 _ECIs located in a shifted position
I have. Hall element h_3RIs the position P on the mover LMm._ThreeOr
28 to the right in FIG._ECIs located in a shifted position
You.

Further, the mover LMm is driven leftward in FIG.
When moving, move to each coil of the armature coil AC.
In this example, the energization timing of the position P on the mover is_TwoFrom
2M to the right_WOffset position, position P_Three2M to right_WShifted
Position, position P_Four2M to right _WAt each of the shifted positions
It is detected based on the polarity of the magnetic pole. Magnetic poles at each of these positions
In order to detect the polarity of
Are three Hall elements h at the next position_1L, H_2L, H_3LIs arranged
Is placed.

[0154] Hall element h _1L, the distance from the position shifted 2M _W to the right in FIG. 28 from the position P ₂ on the movable element LMM, further leftward (drive direction when driving the mover LMM leftward) It is arranged at a position shifted by _DEC . Hall element h _2L from a position shifted 2M _W to the right in FIG. 28 from the position P ₃ on the movable piece LMM, it is disposed further displaced a distance D _EC to the left position. Hall element h _3L is movable element LM
from the position P ₄ on the m from the position shifted 2M _W to the right in FIG. 28, are arranged further shifted distance D _EC to the left position.

Each of these six Hall elements is an electric
Are arranged on the outer peripheral surface of the child coil AC,
I am facing the magnet FM. Six holes like this
By arranging the element, for example, the mover LMm is moved rightward.
When driving, the Hall element h₁Magnetic pole detected by
The phase of the switching position of the mover is as shown in FIG.
Position P on LMm₁The magnetic pole of the field magnet FM
The phase is the same as the phase at the switching position. Hall element h
₁Is the position P on the mover LMm.₁Field magnet F at
The switching position of the magnetic pole of M can be detected. World
Even if the width of each magnetic pole of the magnetic magnet FM varies,
Hall element h ₁Switch position of magnetic pole detected by
Is at the position P on the mover LMm.₁Field magnets at
And the phase of the switching position of the magnetic pole of the FM.
The same applies to other Hall elements.

In the drive control device 4E, these six
The detection signal (output signal) of the Hall element of
Is directly input to the energization control unit 47 as a reset signal. In addition,
The detection signal of the Hall element is amplified and digitized,
It is input to the energization control unit 47. The energization control unit 47 is movable
When the child LMm is driven rightward in FIG.
Element h_1R, H_2R, H_3RArmature coil based on the detected magnetic poles
The timing of energizing each coil of AC
Energize the il. Hall element h_1R, H_2R, H_3RIs
The magnetic field formed by the armature coil AC as shown in FIG.
Acting on the movable element LMm,
P₁, P_Two, P_ThreeOf the field magnet FM at each position
The switching position of the pole can be detected. Therefore, the conventional
Like P ₁, P_Two, P_ThreeHall elements are placed at each position of
To detect the energization timing and energize each coil.
To accurately detect the energization timing of each coil.
The linear motor LM6
Can be driven. Also, the field magnet FM
Even if the width of each magnetic pole varies, the linear motor
As in the case of LM1, the rate of improper energization can be reduced,
Drives the linear motor LM6 with less thrust fluctuation
be able to.

The energization control unit 47 sets the mover LMm in FIG.
When driving in the middle left direction, the Hall elements h _1L , h _2L ,
Based on the detection magnetic poles of h _3L, and detects the energization timing for each coil of the armature coils AC, it energizes the coils.
When the mover LMm is driven in the left direction, the linear motor LM6 can be driven with less fluctuation in thrust as in the case of driving the mover LMm in the right direction.

As described above, the shift amount _EC of the switching position of the magnetic pole detected by the Hall element and the switching position of the corresponding magnetic pole of the field magnet FM at the position where the Hall element is arranged is determined by the armature coil AC It varies depending on the magnitude of the current flowing through. Therefore, the position to be detected the field magnet FM poles on the movable element, the distance D _EC of shifting the Hall element may be determined in the following manner. For example, when a linear motor drive device including the linear motor LM6 and the drive control device 4E is used to drive an article at a constant speed, the magnitude of the current flowing through the armature coil when driving the article at the constant speed is increased. Distance D corresponding to
_EC should be used. By doing so, when driving the article at a constant speed by the linear motor driving device, the mover LMm can be driven with a small thrust variation as described above, and the speed variation can be suppressed accordingly.

[0159]

According to the present invention, there is provided a field magnet in which N-poles and S-poles are alternately arranged linearly in a predetermined direction, and a reciprocating movement along the field magnet facing the field magnet. A linear motor drive device comprising a movable armature coil and a drive control device for controlling energization of the armature coil, wherein the linear motor drive device has one or more of the following advantages (A) to (D): Can be provided. (A) A linear motor drive device capable of accurately detecting a field magnet forming magnetic field at a predetermined position on a mover by suppressing the influence of a magnetic field formed by energization of an armature coil. (B) A linear motor drive device capable of accurately driving a linear motor while suppressing the influence of a magnetic field formed by energization of the armature coil. (C) A linear motor drive device capable of accurately detecting a field magnet forming magnetic field at a predetermined position on a mover, even if the width of each magnetic pole of the field magnet varies. (D) A linear motor driving device capable of driving a linear motor with higher accuracy than before, even if the width of each magnetic pole of the field magnet varies.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing a part of an example of a linear motor according to the present invention in cross section.

FIG. 2 is a schematic sectional view of the linear motor taken along line XX in FIG.

FIG. 3 is a schematic block diagram of an example of a drive control device according to the present invention for pulse-driving the linear motor of FIG. 1;

FIG. 4A is a schematic perspective view of a magnetizing device, and FIG. 4B is a schematic sectional view of the magnetizing device.

5 is a diagram showing a magnetic field distribution in a longitudinal direction of a guide shaft formed by a field magnet of the linear motor in FIG. 1;

6 is a diagram illustrating an example of field magnet information stored in each area of a memory included in the drive control device of FIG. 3;

7 shows the polarity of the magnetic pole of the field magnet at each position on the mover output from the magnetic pole detection unit of the drive control device of FIG. 3 when the linear motor of FIG. 1 is driven rightward in FIG. FIG. 4 is a diagram showing a phase relationship between a signal indicating the following and the energization timing to each coil, and the energization direction to each coil.

8 shows the polarity of the magnetic pole of the field magnet at each position on the mover output from the magnetic pole detection unit of the drive control device of FIG. 3 when the linear motor of FIG. 1 is driven leftward in FIG. FIG. 4 is a diagram showing a phase relationship between a signal indicating the following and the energization timing to each coil, and the energization direction to each coil.

FIG. 9 is a diagram showing the timing of energizing each coil when the width of each magnetic pole of the field magnet varies in the conventional linear motor driving device.

FIG. 10 is a diagram showing the timing of energizing each coil when the width of each magnetic pole of the field magnet varies in the linear motor drive device of the present invention.

11 (A) to 11 (D) are diagrams each showing a moving direction of a mover when currents of the same direction are applied to two adjacent coils.

12 is a diagram showing another example of the field magnet information stored in each area of the memory provided in the drive control device of FIG. 3;

13 is a diagram showing still another example of field magnet information stored in each area of a memory provided in the drive control device of FIG. 3;

FIG. 14 is a schematic block diagram of an example of a drive control device according to the present invention for linearly driving the linear motor of FIG. 1;

15 is a diagram illustrating an example of field magnet information stored in each area of a memory included in the drive control device of FIG. 14;

FIG. 16 is a diagram showing a signal before filtering and a signal after filtering when the field magnet signal is filtered.

FIG. 17 is a schematic side view showing a part of another example of the linear motor according to the present invention in cross section.

18 (A) is a schematic perspective view showing a state where the guide shaft and the magnet scale base of the linear motor shown in FIG. 17 are magnetized, and FIG. 18 (B) is a schematic sectional view showing such a state. is there.

19 is a diagram showing a magnetic field distribution in a longitudinal direction of a guide shaft formed by a field magnet and a magnet scale of the linear motor shown in FIG. 17;

20 is a schematic block diagram of an example of a drive control device according to the present invention for pulse driving the linear motor of FIG.

FIG. 21 is a schematic side view showing a part of still another example of the linear motor according to the present invention in cross section.

FIG. 22 is a schematic block diagram of an example of a drive control device according to the present invention for pulse driving the linear motor of FIG. 21.

In the linear motor shown in FIG. 23 FIG. 21, the field magnet forming the magnetic field at the position P ₁ on the movable element, the Hall element detects a magnetic field which is arranged at a position P _1, the phase relationship of the magnetic field magnetic pole correction section detects FIG.

24 is a diagram showing a field magnet forming magnetic field at a position P ₁ on the mover, a field magnet forming magnetic field at a position P ₂ on the mover, and a hole arranged at the position P ₂ in the linear motor shown in FIG. 21; FIG. 4 is a diagram illustrating a phase relationship between an element detection magnetic field and a magnetic field detected by a magnetic pole correction unit.

FIG. 25 is a schematic side view showing a part of still another example of the linear motor according to the present invention in cross section.

26 is a diagram showing a state of a magnetic field formed by a field magnet of the linear motor shown in FIG. 25 in a cross section perpendicular to the longitudinal direction of the guide shaft.

In the linear motor shown in FIG. 27 FIG. 25, the field magnet forming the magnetic field at the position where the field magnet forming a magnetic field, the Hall elements on the movable member is disposed at the position P ₁ on the movable element, the Hall element detects a magnetic field FIG. 4 is a diagram illustrating a phase relationship of a magnetic field detected by a magnetic pole correction unit.

FIG. 28 is a schematic side view showing a part of still another example of the linear motor according to the present invention in cross section.

FIG. 29 is a schematic block diagram of an example of a drive control device according to the present invention for pulse-driving the linear motor of FIG. 28;

In the linear motor shown in FIG. 30 FIG. 28, the field magnet forming the magnetic field at the position where the field magnet forming a magnetic field, the Hall elements on the movable member is disposed at the position P ₁ on the movable element, the Hall element detects a magnetic field FIG. 4 is a diagram showing a phase relationship of FIG.

FIG. 31 is a schematic side view of an example of a conventional linear motor.

FIG. 32 shows the phase relationship between the magnetic field formed by the field magnet at each position on the mover, the energization timing of each coil, and the timing when the linear motor shown in FIG. 31 is driven rightward in FIG. It is a figure which shows the energization direction of.

FIG. 33 is a diagram showing a field magnet forming magnetic field and a Hall element detection magnetic field when the mover is driven while energizing the armature coil of the linear motor shown in FIG. 31.

[Explanation of symbols]

LM1~LM6 linear motor LMs stator 1 guide shaft FM field magnet LMm mover AC armature coil 31 yoke 321 bearing Ec encoder chart Esa, Esb encoder sensor HI shielding member Hs home sensor h _1, h _2, h ₃ , H _1R , h _2R , h _3R , h _1L , h _2L , h
_3L Hall element 4A, 4B, 4C, 4D, 4E Drive control unit 41 Drive command unit 42 PLL control unit 43 Compensation circuit unit 44 Encoder counter 45 Magnetic pole detection unit 46 Memory 47 Energization control unit 48 Three-phase full-wave current supply circuit 51 Magnetic pole correction Department

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masazo Ishiyama 2-13-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka F-term in Osaka International Building Minolta Co., Ltd. 5H540 BA05 BB04 BB05 EE05 EE13 EE20 FA03 FA11 FA30 5H641 BB03 BB14 BB18 GG03 GG05 GG08 GG25 GG26 GG28 HH02

Claims (16)

[Claims] 1. A field magnet in which N-poles and S-poles are alternately linearly arranged in a predetermined direction, and an electric machine which faces the field magnet and can reciprocate along the field magnet. A slave coil, a linear encoder scale extending in the predetermined direction, an encoder sensor that moves together with the armature coil and faces the linear encoder scale, and a position of the armature coil in the predetermined direction from detection information of the encoder sensor. A position detecting device capable of detecting; a memory for storing magnetic field information formed by the field magnet at each position in the predetermined direction; and a predetermined direction of the armature coil detected by the position detecting device. Magnetic field information is read from the memory based on the position of the armature coil, and a predetermined position in the predetermined direction on the armature coil is read. A magnetic field detection device capable of detecting magnetic field information of the field magnet at a time, and energizing control to the armature coil based on magnetic field information at a predetermined position on the armature coil detected by the magnetic field detection device A linear motor drive device comprising a drive control device. 2. A field magnet in which N-poles and S-poles are alternately arranged linearly in a predetermined direction, and an electric machine which faces the field magnet and can reciprocate along the field magnet. A child coil, and N magnetic poles and S magnetic poles are alternately arranged in the predetermined direction,
A magnet scale that forms a magnetic field proportional to a magnetic field formed by the field magnet in the predetermined direction; a magnetic sensor that moves together with the armature coil and faces the magnet scale; and a magnetic scale that is detected by the magnetic sensor. A linear motor drive device comprising: a drive control device that controls energization of the armature coil based on a formed magnetic field. 3. The linear motor driving device according to claim 2, wherein a magnetic shield member is disposed between said magnetic sensor and said armature coil. 4. The field magnet is formed by magnetizing a field magnet base made of a magnetic material, and the magnet scale is magnetized on a magnet scale base made of a magnetic material simultaneously with the field magnet base. The linear motor drive device according to claim 2, wherein the linear motor drive device is formed by performing the following. 5. A state in which said magnet scale base is temporarily attached to said field magnet base in a removable manner.
The field magnet and the magnet scale are formed by simultaneously magnetizing the two substrates.
The linear motor drive as described. 6. The linear motor driving device according to claim 2, wherein the magnet scale is formed by bringing a magnet scale base made of a magnetic recording material close to or in contact with the field magnet. 7. A field magnet in which N-poles and S-poles are alternately arranged linearly in a predetermined direction, and an electric machine which faces the field magnet and can reciprocate along the field magnet. A slave coil, a linear encoder scale extending in the predetermined direction, an encoder sensor that moves together with the armature coil and faces the linear encoder scale, and a moving direction of the armature coil that determines the number of encoder pulses detected by the encoder sensor. An encoder counter that counts up and down according to the following: and a magnetic field formed by the field magnet that is supported by the armature coil and acts on the armature coil at a predetermined position in the predetermined direction on the armature coil. A magnetic sensor for energizing the armature coil, and causing the armature coil to Error between the magnetic pole switching position of the magnetic field formed by the field magnet at a predetermined position on the armature coil and the corresponding magnetic pole switching position of the magnetic field detected by the magnetic sensor when moving along the armature coil. Distance D
A correction device for correcting _E based on the encoder count number counted by the encoder counter, and detecting a switching position of a magnetic pole of a magnetic field formed by the field magnet at a predetermined position on the armature coil. A linear motor drive device comprising: a drive control device that controls energization of the armature coil based on a switching position of a magnetic pole at a predetermined position on the armature coil detected by the correction device. . 8. A switching position of a magnetic pole formed by the field magnet at a predetermined position on the armature coil when the error distance _DE is changed by a switching of a corresponding magnetic pole of a magnetic field detected by the magnetic sensor. than the position, positive when a position advanced in the driving direction of said armature coils, lag and negative when it is located, the width in the predetermined direction one pole of the field magnet as M _W, wherein When the error distance _DE is positive, the correction device detects the magnetic pole detected by the magnetic sensor at a position where the armature coil is advanced by the distance _{DE in the} driving direction from the switching position of the magnetic pole detected by the magnetic sensor. The switching of the magnetic pole is performed in the same manner as the switching of the magnetic field, and the switching position of the magnetic pole of the magnetic field formed by the field magnet at a predetermined position on the armature coil is detected. When the error distance D _E is negative, the switching position of the magnetic poles of the magnetic sensor detects the armature coil distance in the driving direction _{(M W - | D E |} ) advanced in position,
8. The switching of magnetic poles opposite to the switching of magnetic poles detected by the magnetic sensor is performed to detect a switching position of a magnetic pole formed by the field magnet at a predetermined position on the armature coil. Linear motor drive. 9. The drive control device detects a timing of energizing the armature coil based on a switching position of a magnetic pole at a predetermined position on the armature coil detected by the correction device. 9. A pulse current is applied to the coil.
The linear motor drive as described. 10. A distance between a predetermined position on the armature coil in the predetermined direction and an arrangement position of the magnetic sensor is defined as D _EA , and the distance D _EA is defined as an arrangement position of the magnetic sensor. When the position is advanced in the driving direction of the armature coil from a predetermined position on the coil, the position is positive, and when the position is delayed, the position is negative. When moving along the magnet, between the switching position of the magnetic pole of the magnetic field formed by the field magnet at the position where the magnetic sensor is disposed, and the switching position of the corresponding magnetic pole detected by the magnetic sensor The distance of D
And _EC, the distance D _EC, the said field magnet switches of the magnetic poles of the magnetic field forming position at the position where the magnetic sensor is disposed, than the corresponding switching position of the magnetic poles of the magnetic field which the magnetic sensor detects , as a negative when when the a position advanced in the driving direction of the armature coils positive, delayed position, wherein the correction device, the distance D _EA and the distance D the sum of _EC (D
8. The linear motor drive according to claim 7, wherein ( _EA + _DEC ) is the error distance _DE . 11. When the width of one magnetic pole of the field magnet in the predetermined direction is M _W , the correction device is configured such that, when the error distance _DE is positive, the switching position of the magnetic pole detected by the magnetic sensor is changed. At the position where the armature coil is advanced by the distance _{DE in the} driving direction, correction is performed to switch the magnetic pole in the same manner as switching of the magnetic pole detected by the magnetic sensor. The switching position of the magnetic pole of the magnetic field formed by the magnetic magnet is detected, and when the error distance _DE is negative, the armature coil is moved in the driving direction from the switching position of the magnetic pole detected by the magnetic sensor in the driving direction ( _MW). − | D _E |)
11. The switching of magnetic poles, which is opposite to the switching of magnetic poles detected by the magnetic sensor, is performed to detect a switching position of a magnetic pole formed by the field magnet at a predetermined position on the armature coil. Linear motor drive. 12. The correction device according to claim 1, wherein said error distance _DE is zero.
Wherein the magnetic pole is switched in the same manner as the switching of the magnetic pole detected by the magnetic sensor, and the switching position of the magnetic pole of the magnetic field formed by the field magnet at a predetermined position on the armature coil is detected. 10 or 11
The linear motor drive as described. Wherein said correction device includes a linear motor driving device according to any one of the distance D the value of _EC claims 10 vary depending on the power supply amount to the armature coils 12. 14. The drive control device detects an energization timing to the armature coil based on a switching position of a magnetic pole at a predetermined position on the armature coil detected by the correction device. 14. The linear motor driving device according to claim 10, wherein a pulse current is applied to the coil. 15. The magnetic sensor by supplying a current having a predetermined current value to the armature coils, when moving along the armature coil to said field magnet, and the error distance D _E 0 Claims 10 to 1 which are arranged at different positions
5. The linear motor driving device according to any one of 4. 16. A field magnet in which N-poles and S-poles are alternately linearly arranged in a predetermined direction, and an electric machine capable of facing the field magnet and reciprocating along the field magnet. A magnetic sensor that moves with the armature coil and detects a magnetic field formed by the field magnet acting on the armature coil at a predetermined position in the predetermined direction on the armature coil; A drive control device that controls energization of the armature coil based on magnetic field information detected by the magnetic sensor, wherein the magnetic sensor supplies a current of a predetermined current value to the armature coil, When the coil is moved along the field magnet, a switching position of a magnetic pole of a magnetic field formed by the field magnet at a position where the magnetic sensor is arranged; A linear motor driving device disposed at a position deviated in the predetermined direction from a predetermined position on the armature coil by a distance from a switching position of a corresponding magnetic pole detected by the motor.