JP2001003245A - Linear motor controller for driving knitting members in knitting machines - Google Patents

Abstract

(57) Abstract: To prevent accumulation of detection errors of relative positions y of magnetic poles of stators M1 and M2 of a linear motor M. A knitting control unit is combined with a drive control circuit, a drive circuit, and a pole position detector. For example, when the stop switch SW2 is operated,
The knitting control unit 10 retreats the knitting member W to the retreat limit via the drive control circuit 21 and the drive circuit 22, and outputs a clear signal S5. The drive circuit 22 resets the pole position detector 22a according to the clear signal S5. Outputs the signal S7,
The relative position y of the magnetic poles of the stator M1 and the mover M2 detected by the pole position detector 22a via the sensor A is correctly corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor controller for driving a knitting member in a knitting machine capable of preventing knitting of a defective knitted fabric and stably knitting a high-quality knitted fabric.

[0002]

2. Description of the Related Art There is known a flat knitting machine in which knitting members such as a plurality of yarn feeders and knitting needles on front and rear beds are individually position-controlled by a linear motor.

[0003] Each linear motor is combined with a drive control circuit and a drive circuit, and is position-controlled in accordance with a target position signal from a common knitting control unit. Further, the drive circuit includes a pole position detector that detects the relative positions of the magnetic poles of the stator and the mover of the linear motor based on a detection signal from a sensor that detects an amount of movement of the mover of the linear motor. When the power is turned on, a reset signal is output to the pole position detector to reset the pole position detector. Therefore, the drive circuit selects a predetermined coil of the linear motor according to the relative position of the magnetic poles of the stator and the mover detected via the pole position detector, outputs a drive current, and controls the drive of the linear motor correctly. be able to.

[0004]

According to the prior art, when the pulse-like detection signal from the sensor is lost during the operation of the flat knitting machine, the polar position detector detects the relative position of the magnetic poles of the stator and the mover. Position cannot be detected correctly,
If detection errors accumulate, the linear motor vibrates little by little when the knitting member should be kept stationary, or the linear motor does not operate smoothly, making it difficult to accurately control the position of the knitting member. There has been a problem that defective portions such as falling and vertical streaks are generated on the knitted fabric.

SUMMARY OF THE INVENTION In view of the above-mentioned problems in the prior art, an object of the present invention is to reset the pole position detector in accordance with a clear signal from the knitting control unit so that errors in detection of relative positions of magnetic poles are excessively accumulated. It is an object of the present invention to provide a linear motor control device for driving a knitting member in a knitting machine capable of stably knitting a high quality knitted fabric by always accurately controlling the position of a knitting member.

[0006]

According to the present invention, there is provided a drive control circuit for detecting a positional deviation of a knitting member driven by a linear motor, and detecting a movement amount of a movable element of the linear motor. And a predetermined coil of a linear motor based on a drive signal from a drive control circuit and a pole position signal from the pole position detector. And a driving circuit that outputs a driving current to the pole position detector. The gist of the invention is to reset the polar position detector in accordance with a clear signal from the knitting control unit on condition that the mover is at a predetermined position.

[0007] The pole position detector can be reset by a reset signal from a drive circuit.

Further, the drive circuit may output a reset signal after confirming that the movable element is at the backward limit, and further confirm that the movable element at the backward limit is being driven backward. A reset signal may be output.

However, the drive circuit can output the reset signal after confirming that the clear signal from the composition control unit has continued for a predetermined duration.

[0010]

According to the structure of the present invention, each time the clear signal is generated from the knitting control unit, the pole position detector is reset on condition that the mover is at the predetermined position. In other words, regardless of the length of operation time of the knitting machine, the pole position detector minimizes the accumulation of detection errors due to the lack of a detection signal from the sensor to accurately determine the relative positions of the magnetic poles of the stator and the mover of the linear motor. The drive control circuit and the drive circuit can correctly control the position of the knitting member via the linear motor. In the knitting control unit, the clear signal is output when the power of the knitting machine is turned on, when knitting of one or two or more knitted fabrics is completed, or when the knitting machine is turned off via a stop switch. It occurs after the knitting member is driven to a predetermined position such as a retreat limit or a forward limit, for example, when the machine is manually stopped.

However, in the present invention, the "predetermined position"
The term “removal limit” and “advance limit” refers to any set position within the moving stroke of the mover where the position of the mover can be accurately detected.

On the other hand, the drive control circuit compares the target position output from the knitting control unit as a target position signal with the current position of the mover of the linear motor based on knitting data from the outside. The deviation is detected and a drive signal is output. However, the target position at this time is to drive the knitting member according to a predetermined speed pattern.
It changes to the final target position with time.

A reset signal for resetting the pole position detector is output from the drive circuit, and by setting appropriate conditions in the drive circuit, the noise resistance as a whole can be easily improved.

[0014] For example, the drive circuit can confirm that the clear signal from the knitting control unit is not an erroneous signal due to noise by confirming that the movable element is at the retreat limit. There is no output. When the drive signal from the drive control circuit indicates the duty ratio of the drive current of the linear motor, the drive circuit, for example, detects that the duty ratio is 0% and confirms that the movable element is at the retreat limit. Can be.

The drive circuit outputs a reset signal when the movable element is pressed against the rear stopper by confirming that the movable element at the retreat limit is driven rearward, and outputs a reset signal. Can be reset, and malfunctions due to noise can be more effectively prevented, and the relative position of the magnetic poles thereafter can be reduced by strictly holding the position of the mover when the pole position detector is reset to the retreat limit. Detection can be performed more accurately.

The drive circuit confirms that the clear signal from the knitting control unit has continued for a predetermined duration, thereby making the conditions for outputting the reset signal more strict and enhancing the noise resistance as a whole. can do.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

A linear motor control device for driving a knitting member in a knitting machine includes a drive control circuit 21 and a drive circuit 22 cascaded (FIG. 1). It is combined with the control unit 10. However, FIG. 1 shows a set of drive control circuits 21,
Only the drive circuit 22, the linear motor M, and the knitting member W are illustrated, and each knitting member W is an arbitrary yarn feeder, a knitting needle, and the like of a flat knitting machine driven by the linear motor M. In addition,
The knitting machine may be of a type other than a flat knitting machine.

The linear motor M has a stator M1 in which N-pole and S-pole permanent magnets are alternately arranged in the moving direction of the knitting member W.
And a mover M2 having a plurality of coils M2a, M2a. Stator M of linear motor M
On the 1 side, a sensor A for detecting the amount of movement of the mover M2 is provided via a scale M2b attached to the mover M2. A knitting member W is connected to the mover M2, and a stopper SP for limiting the retreat limit of the mover M2 and the knitting member W is provided behind the mover M2. The sensor A outputs a pulse-like detection signal Sa for each scale pitch of the scale M2b.

The knitting control unit 10 is provided with a start switch SW1 and a stop switch SW2, and receives knitting data D1 from a data unit (not shown).
The output of the knitting control unit 10 is individually input to the drive control circuit 21 as a target position signal S3 and a control signal S4, and is input to the drive circuit 22 as a clear signal S5.

The drive control circuit 21 includes a current position detector 2
1a is attached. The detection signal Sa from the sensor A is input to the current position detector 21a, and the output of the current position detector 21a is input to the drive control circuit 21 as the current position signal Sx. The output of the drive control circuit 21 is input to the drive circuit 22 as a drive signal S6. The output of the drive circuit 22 is the mover M of the linear motor M.
2 coils M2a, M2a
Is output as the reset signal S7 from the pole position detector 2
2a. The detection signal Sa from the sensor A is branched and input to the pole position detector 22a, and the output of the pole position detector 22a is input to the drive circuit 22 as a pole position signal Sy.

When the power of the flat knitting machine is turned on, knitting data D1 from a data unit (not shown) is input to the knitting control unit 10. When the start switch SW1 is operated, the knitting control unit 10 can output the target position signal S3 to the drive control circuit 21 based on the knitting data D1. The target position signal S3 indicates a target position xo of the knitting member W that changes with time for each knitting member W based on the knitting data D1.
Further, the current position detector 21a outputs the current position x of the knitting member W as the current position signal Sx based on the detection signal Sa from the sensor A. However, the current position x is measured forward from the knitting origin (not shown) set in front of the stopper SP in the moving direction of the knitting member W.

The drive control circuit 21 includes the knitting control unit 1
0, and the current position x from the current position detector 21a is compared with the position deviation Δx = x of the knitted member W.
−x o, and based on the position deviation Δx, the position deviation Δx
Drive current Id of the linear motor M necessary to eliminate the
Is output to the drive circuit 22 as a drive signal S6. When the drive current Id is a PWM-modulated rectangular wave current, the command value d indicates the duty ratio of the drive current Id, and the moving direction of the mover M2 and the knitting member W is indicated by a sign.

On the other hand, the pole position detector 22a has a counter function, counts the pulse-like detection signal Sa from the sensor A in the forward and reverse directions according to the moving direction of the movable element M2, The relative position y of the magnetic pole of the mover M2 can be detected and output as a pole position signal Sy. Therefore, the drive circuit 22 selects a predetermined coil M2a of the linear motor M based on the drive signal S6 from the drive control circuit 21 and the pole position signal Sy from the pole position detector 22a, and selects an appropriate coil M2a for the selected coil M2a. By outputting a drive current Id of appropriate direction and magnitude, the knitting member W can be driven via the linear motor M to follow a temporal change of the target position xo to knit a predetermined knitted fabric. it can.

The knitting control unit 10 operates according to the program flow chart of FIG. 2 when the power of the flat knitting machine is turned on or when knitting of a predetermined amount of the knitted fabric specified by the knitting data D1 is completed. However, in the latter case, the program of FIG. 2 operates periodically according to the knitting amount of the knitted fabric.

The program first outputs, as a target position signal S3, a target position xo having a retreat limit as a final target position for each knitting member W (program step (1) in FIG. 2, hereinafter simply (1)). Like this). Therefore, the drive control circuit 21 outputs a drive signal S6 in the retreat direction of the command value d = b to the drive circuit 22, and retreats the mover M2 of the linear motor M to abut on the rear stopper SP (FIG. 4). At time t = to to t1, hereinafter simply (t = to to t1)
))). However, FIG. 4 shows that the mover M2 and the knitting member W are at the knitting origin at time t <to. Subsequently, the program is executed by the mover M
After the elapsed time required for 2 to retreat to the retreat limit (2),
The control signal S4 is output to the drive control circuit 21 (3), and the command value d =
It is set to 0 (t = t1). However, the program step (2) includes the current position signal S from the current position detector 21a.
Based on x, it may be detected that the mover M2 has retreated to the retreat limit.

Next, the program executes a predetermined standby time T1.
= T2 -t1 and outputs the clear signal S5 ((4), (5)), and re-outputs the control signal S4 after the next standby time T2a = t2a -t2 ((6), (7)) . Therefore, the drive control circuit 21 responds to the control signal S4 by
A command signal d = a is output in the reverse drive signal S6 (t ≧
t2a) The movable element M2 at the retreat limit via the drive circuit 22
Can be pressed against the stopper SP. In order to press the mover M2 against the stopper SP with an appropriate force, it is generally preferable to set 0 <a <b.

Thereafter, the program calculates the elapsed time T2b = t
After the elapse of 3-t2a (8), the clear signal S5 is extinguished (9). That is, the clear signal S5 is continuously output for the duration T2 = t3-t2. Subsequently, the program waits for the elapsed time T3 = t4-t3 (10), outputs the target position xo having the knitting origin of the knitting member W as the final target position as the target position signal S3, and ends (11). ). Thus, the drive control circuit 21 outputs a drive signal S6 in the forward direction with the command value d = -b, and advances the knitting member W from the retreat limit to the knitting origin via the drive circuit 22 (t = t4 to t5). ), And can be made to stand by (t> t5).

On the other hand, the drive circuit 22 operates according to the program flowchart of FIG. 3 in response to the clear signal S5 from the knitting control unit 10 (t = t2).

That is, the program includes the clear signal S5
When the operation is started by the rising edge of the linear motor M, the command value d = 0 of the drive signal S6 is confirmed (program step (1) in FIG. 3, hereinafter simply referred to as (1)). It can be recognized that M2 is in the retreat limit. When the command value d is not 0 (1), the program determines that the mover M2 is not at the retreat limit and ends the program.

Subsequently, the program monitors whether or not the clear signal S5 from the knitting control unit 10 is normally continued within a predetermined duration T2 ((2),
(3)) When the clear signal S5 disappears within the duration T2, the process ends. In the program, the clear signal S5 continues for the duration T2 ((2), (3)),
After that, when it disappears regularly (4), the monitoring time T3a = t3a
It is confirmed that the command value d = a of the drive signal S6 over -t3 <T3 ((5), (6)), and the reset signal S7
Is output to the pole position detector 22a, and the process ends (7). Therefore, the pole position detector 22a is configured such that the mover M2 is connected to the stopper SP.
Is reset, the count value of the detection signal Sa from the sensor A is reset. Thereafter, the relative positions y of the magnetic poles of the stator M1 and the mover M2 are accurately detected and output as a pole position signal Sy. be able to.

The same applies when the stop switch SW2 is operated during knitting of a knitted fabric or when the flat knitting machine automatically stops for some reason. However, the knitting control unit 10 at this time sets the target position x indicated by each target position signal S3.
is temporarily held when the stop switch SW2 is operated and the flat knitting machine is automatically stopped, the target position signal S3, the control signal S4, and the clear signal S5 are output in accordance with the above-described procedure, and the drive circuit 22 clears. The reset signal S7 is output according to the signal S5, and the pole position detector 22a is output.
Reset. Then, after that, the start switch SW1
Is operated, the knitting control unit 10 releases the hold of each target position signal S3 to restart the temporal change of the target position xo based on the knitting data D1, and the drive control circuit 2
1. Via the drive circuit 22, the position control of the knitting member W by the linear motor M can be started to restart knitting.

That is, the drive circuit 22 outputs the clear signal S
5, when the command value d = 0 of the drive signal S6 from the drive control circuit 21, it is confirmed that the mover M2 is at the retreat limit, and then the clear signal S5 is set to the duration T2.
Further, since the command value d = a of the drive signal S6 after the clear signal S5 disappears, the movable element M2 at the retreat limit is driven backward and the stopper SP
After confirming that the signal is pressed, the reset signal S7 is output. Therefore, after the generation of the clear signal S5, the drive circuit 22 outputs the reset signal S7 only when a predetermined condition is satisfied, so that even if the clear signal S5 is erroneously generated due to noise, the drive circuit 22 outputs the reset signal S7. There is no risk of resetting carelessly.

However, the drive circuit 22 outputs the clear signal S5
At the time of input, it is confirmed that the command value d = 0 of the drive signal S6 from the drive control circuit 21 and immediately the reset signal S7
May be output. Further, the drive circuit 22 confirms that the command value d of the drive signal S6 is 0 when the clear signal S5 is inputted, and thereafter, the command value d = a of the drive signal S6 when the clear signal S5 disappears. After confirming this, the reset signal S7 may be output. Further, the reset signal S7 may be output when the clear signal S5 continues for the duration T2, and when the clear signal S5 is input, it is confirmed that the command value d = 0 of the drive signal S6.
Thereafter, the reset signal S7 may be output when the clear signal S5 continues for the duration T2.

Incidentally, the reset signal S7 is supplied to the drive circuit 22.
Alternatively, the knitting control unit 10 may directly output to the polar position detector 22a. At this time, the knitting control unit 10 may control the drive control circuit 21 and the drive circuit 22 according to the time chart of FIG. 4 and output the reset signal S7 without outputting the clear signal S5.

In the above description, the retreat limit of the mover M2 and the knitting member W by the stopper SP is limited as long as the relative positions y of the magnetic poles of the stator M1 and the mover M2 can be mechanically correctly defined. May be set to any setting position. However, the fact that the mover M2 is at a set position other than the retreat limit and the forward limit is detected by a dedicated sensor other than the sensor A, and the knitting control unit 10 executes the program steps (1) and (2) in FIG. , Mover M
2 may be driven toward the set position to detect that the mover M2 has reached the set position.

[0037]

As described above, according to the present invention, by resetting the polar position detector according to the clear signal from the knitting control unit, the polar position detector can
Even if the pulse-like detection signal from the sensor that detects the moving amount of the linear motor mover is missing, the stator,
Since the detection error of the relative position of the magnetic poles of the mover can be prevented from being excessively accumulated and its influence can be minimized, the position of the knitting member can always be controlled correctly and smoothly via the linear motor to achieve high quality. There is an excellent effect that the knitted fabric can be stably knitted.

[Brief description of the drawings]

FIG. 1 is a block diagram of the overall configuration

FIG. 2 is a program flowchart (1).

FIG. 3 is a program flowchart (2).

FIG. 4 is an operation explanatory diagram.

[Explanation of symbols]

 W ... knitting member M ... linear motor M1 ... stator M2 ... mover M2a ... coil A ... sensor y ... relative position Δx ... position deviation T2 ... duration Id ... drive current S5 ... clear signal S6 ... drive signal S7 ... reset signal Sy ... Polar position signal 10 ... Knitting control unit 21 ... Drive control circuit 22 ... Drive circuit 22a ... Polar position detector

Continued on the front page (72) Atsushi Takashima, 5-18-18 Nomachi, Kanazawa-shi, Ishikawa Prefecture Inside Tsudakoma Kogyo Co., Ltd. (72) Tatsuya Tani 5-18-18, Nomachi, Kanazawa-shi, Ishikawa Tsudakoma Industrial Co., Ltd. In-house (72) Inventor Yutaka Matsuyama 8-2 Hinikocho E, Tsurugai-cho, Ishikawa-gun, Ishikawa F-term (reference) 4L054 DA04 NA02 NA03 NA04

Claims (5)

[Claims] 1. A drive control circuit for detecting a positional deviation of a knitting member driven by a linear motor, and a relative position of a stator and a magnetic pole of the mover are detected via a sensor for detecting a moving amount of a mover of the linear motor. And a drive circuit that outputs a drive current to a predetermined coil of the linear motor based on a drive signal from the drive control circuit and a pole position signal from the pole position detector, According to the clear signal from the knitting control unit, the pole position detector
A linear motor control device for driving a knitting member in a knitting machine, wherein the reset is performed on condition that the mover is at a predetermined position. 2. The linear motor control device for driving a knitting member in a knitting machine according to claim 1, wherein the pole position detector is reset by a reset signal from the drive circuit. 3. The linear motor control device for driving a knitting member in a knitting machine according to claim 2, wherein the drive circuit outputs a reset signal after confirming that the movable element is at the retreat limit. 4. The knitting machine according to claim 2, wherein the drive circuit outputs a reset signal after confirming that the movable member at the retreat limit is driven backward. Linear motor control device. 5. The drive circuit according to claim 2, wherein the drive circuit outputs a reset signal after confirming that the clear signal from the composition control unit has continued for a predetermined duration.
A linear motor control device for driving a knitting member in the knitting machine according to any one of claims 4 to 5.