JP2014066525A - Angle detector for body of rotation - Google Patents

Abstract

An object of the present invention is to provide an angle detection device for a rotating body that can increase the area of a coil and has an excellent S / N ratio.
An angle detection device for a rotating body includes a rotor and a stator disposed opposite to the rotor via a gap. The stator 20 includes one unit output coil group including four output coils and one unit primary coil group including four primary coils, and the rotor 30 includes two unit secondary coil groups. Each of the four secondary coils included in one unit secondary coil group has the same winding direction and an electrical angle of 360 ° among the four secondary coils included in another unit secondary coil group. Is connected to the secondary coil at the phase difference position. While the rotor 30 is rotating, one of the two connected secondary coils faces the primary coil included in the unit primary coil group, and the other faces the output coil included in the unit output coil group.
[Selection] Figure 1

Description

  The present invention relates to an angle detection device for a rotating body.

  There is a resolver as an angle detection device for a rotating body such as a motor. A resolver is a type of sensor that detects the angle of a rotating body based on a change in induced electromotive force generated by electromagnetic induction, and is characterized by a simple structure and high environmental resistance.

  In Patent Document 1, a rotating side core that is made to face a fixed side core via a gap, a primary transformer provided on the fixed side core, and a secondary transformer provided on the rotary side core; There is disclosed a rotary transformer type resolver comprising a signal generating unit comprising an excitation winding provided on a rotation side core and a detection winding provided on a fixed side core. This resolver applies an alternating current to a primary side winding provided near the axis of the fixed side core and applies an induced electromotive force to a secondary side winding provided on the rotation side core. At this time, the induced electromotive force appearing in the secondary winding is constant regardless of the rotation angle of the rotating core. An alternating current is passed through a plurality of excitation windings provided outside the secondary winding using the induced electromotive force appearing in the secondary winding as drive power. A plurality of detection windings are provided outside the primary winding of the fixed core. The opposing area of the excitation winding and the detection winding changes according to the rotation angle of the rotation side core, an induced electromotive force is generated in the detection winding, and a sinusoidal signal is output. The detection winding outputs two types of signals whose phases are shifted by 90 degrees, and calculates the rotation angle based on these signals.

  Patent Document 2 discloses a sheet coil resolver that includes two stators and one rotor, and the stator is disposed so as to sandwich the rotor. On the surface of one stator of the resolver, a fixed side sheet coil is provided on the entire surface as a primary side pattern. A secondary pattern is provided on the entire surface of the rotor so as to face the primary pattern, and a resolver excitation phase pattern is provided on the other surface. The other stator surface is provided with a resolver detection phase pattern opposite to the resolver excitation phase pattern. An alternating current is applied to the primary pattern, and an induced electromotive force is applied to the secondary pattern. At this time, the induced electromotive force appearing in the secondary pattern is constant regardless of the rotation angle. An alternating current is passed through the resolver excitation phase pattern using the induced electromotive force appearing in the secondary pattern as drive power. The opposing area of the resolver excitation phase pattern and the resolver detection phase pattern changes according to the rotation angle of the rotor, an induced electromotive force is generated in the resolver detection phase pattern, and a sinusoidal signal is output. The resolver detection phase pattern outputs two types of signals whose phases are shifted by 90 degrees, and calculates the rotation angle based on these signals.

Japanese Patent Laid-Open No. 8-136211 JP-A-11-325964

  In the rotary transformer type resolver disclosed in Patent Document 1, a primary side winding is formed in the center of the fixed side core and a secondary side winding is formed in the center of the rotation side core. The coil area of the detected winding and the excitation winding is reduced. Therefore, the induced electromotive force generated in the excitation winding cannot be increased, and as a result, the output of the detection winding cannot be increased. Therefore, there is a problem that the S / N ratio is small and it is easily affected by external noise.

  In the sheet coil type resolver disclosed in Patent Document 2, since the secondary side pattern and the resolver excitation phase pattern are provided on the front and back of the rotor, the resolver excitation phase pattern forms a coil using the entire surface of the rotor. And a large induced electromotive force can be generated. However, since two stators and one rotor are stacked with gaps in the axial direction, there is a problem that the size of the entire resolver increases.

  In view of the above problems, an object of the present invention is to provide an angle detection device for a rotating body that can increase the area of a coil and has an excellent S / N ratio.

  In order to solve the above-described problems, a characteristic configuration of an angle detection device for a rotating body according to the present invention includes a shaft, a rotor arranged coaxially with the shaft, and rotating integrally with the shaft, and the rotor. A stator disposed opposite to the coaxial core via a gap, and the stator is further adjacently arranged in the circumferential direction to two output coils adjacently arranged in the circumferential direction and connected in series with the winding direction being reversed. One or more unit output coil groups including two output coils connected in series with the same winding direction, and four primary coils arranged adjacent to each other in the circumferential direction and connected in reverse to each other in the winding direction. The unit secondary coil group includes the same number of unit primary coil groups as the unit output coil group, and the rotor includes four secondary coils that are arranged adjacent to each other in the circumferential direction and whose winding directions are opposite to each other and insulated. The sum of the unit output coil group and the unit primary coil group The secondary coils of one unit secondary coil group have the same number, and the winding direction is the same among the secondary coils of another unit secondary coil group and has an electrical angle of 360 ° phase difference. It is connected to the secondary coil arranged at an integral multiple, and when the current flows to each of the secondary coils of one unit secondary coil group, the current flows to each of the secondary coils. The direction of the current and the direction of the current flowing through each of the secondary coils connected to each other are continuous in units of two adjacent to the same direction and the opposite direction, and always connected during rotation of the rotor. One of the secondary coils is opposite to the primary coil, and the other is opposite to the output coil.

  With such a characteristic configuration, in both the power transmission from the unit primary coil group to the unit secondary coil group and the power transmission from the unit secondary coil group to the unit output coil group, the coil facing area is reduced. Since the output voltage changes accordingly, a larger amount of voltage change can be obtained with respect to the rotation of the rotor, and the S / N ratio can be improved. Further, it is possible to convert rotation angle information into an output voltage by all the coils arranged in the rotor, and the rotation angle can be detected efficiently. Furthermore, since the two output coils of the unit output coil group are connected in series with the winding direction being reversed, a push-pull structure can be formed, and the influence of noise due to an external magnetic field can be suppressed.

  In the angle detection device for a rotating body according to the present invention, the gap between the stator and the rotor has an axial direction, and all the output coils and all the primary coils are insulating layers. It is preferable that each of the output coil and the primary coil is wound so that coils of all layers are connected in series and current flows in the same direction.

  Since the coil sheet is usually formed by patterning a copper foil or a copper thin film layer, it is difficult to increase the number of coil turns. However, with such a configuration, it is possible to increase the output voltage by increasing the number of turns of the coil, and it is possible to obtain a coil sheet having a good S / N ratio against external noise.

It is a longitudinal cross-sectional view showing the structure of the angle detection apparatus of the rotary body which concerns on 1st Embodiment. It is explanatory drawing showing the winding state of the coil mounted in the stator. It is explanatory drawing showing the winding state of the coil mounted in the rotor. It is a schematic diagram for demonstrating normal connection. It is a schematic diagram for demonstrating reverse connection. It is a table | surface showing the positive / negative relationship of the applied voltage and output voltage for every combination of the winding direction of a primary coil and an output coil, and the connection method of a secondary coil. It is a table | surface showing the 1st output voltage and the 2nd output voltage for every rotation angle of 45 degrees. It is a graph showing the change of the 1st output voltage when changing a rotation angle from 0 degrees-180 degrees. It is a graph showing the change of the 2nd output voltage when changing a rotation angle from 0 degrees-180 degrees. It is a schematic diagram showing the stationary-side coil sheet | seat of the angle detection apparatus which concerns on 2nd Embodiment. It is a schematic diagram showing the rotation side coil sheet | seat of the angle detection apparatus which concerns on 2nd Embodiment. It is a schematic diagram showing the stationary-side coil sheet | seat of the angle detection apparatus which concerns on 3rd Embodiment. It is a schematic diagram showing the rotation side coil sheet | seat of the angle detection apparatus which concerns on 3rd Embodiment.

1. 1st Embodiment [The structure of the whole angle detection apparatus of a rotary body]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view showing the structure of a rotating body angle detection device (hereinafter referred to as an angle detection device) 10 according to this embodiment. The angle detection device 10 includes a stator 20, a rotor 30, a shaft 40, a case 50, a cover 60, and bearings 70a and 70b.

  As shown in FIG. 1, the angle detection device 10 includes a disk-shaped stator 20 and a rotor 30 having the same outer diameter, facing each other with a gap, and a metal in a coaxial core opening that is opened in the center. A shaft 40 made of metal is inserted. The stator 20 and the shaft 40 are not in contact with each other. The rotor 30 is fixed to the shaft 40 by a method such as press fitting or bonding, and rotates together with the shaft 40. Bearings 70 a and 70 b are press-fitted outside the stator 20 and the rotor 30 of the shaft 40. The bearing 70 a is fitted into a recess formed at the center of the metal case 50, and the bearing 70 b is fitted into a recess formed at the center of the metal cover 60. The stator 20 is fixed to the case 50. The case 50 and the cover 60 are joined by bonding, welding, or other methods.

  The stator 20 has a fixed side coil sheet 22 disposed on a back yoke 21. The back yoke 21 has a disk shape made of a magnetic material such as ferrite, and an opening is formed in the center with a coaxial core. The stationary coil sheet 22 includes a surface coil sheet 22a facing the rotor 30, a back coil sheet 22b facing the back yoke 21, and an insulating layer 22c between the surface coil sheet 22a and the back coil sheet 22b. . The two surfaces of the front coil sheet 22a and the back coil sheet 22b that are not opposed to the insulating layer 22c are both covered with an insulating film (not shown).

  The rotor 30 has a rotating side coil sheet 32 disposed on a back yoke 31. The back yoke 31 has a disk shape made of a magnetic material such as ferrite, and an opening is formed in the center with a coaxial core. The rotation side coil sheet 32 includes a surface coil sheet 32a facing the stator 20, a back sheet 32b facing the back yoke 31, and an insulating layer 32c between the surface coil sheet 32a and the back sheet 32b. The two surfaces of the front coil sheet 32a and the back sheet 32b that are not opposed to the insulating layer 32c are both covered with an insulating film (not shown).

  Input terminals 23e and 23f and output terminals 25c, 25d, 26c and 26d connected to the coil ends of the stator 20 are attached from the upper surface of the case 50. The input terminals 23e and 23f are connected to an AC power source 80.

[Structure of stator]
FIG. 2 is an explanatory diagram showing the winding state of the coil of the fixed-side coil sheet 22 when viewed from the direction A in FIG. In FIG. 2, the upper coil sheet is the front coil sheet 22a and the lower coil sheet is the back coil sheet 22b. As shown in FIG. 2, eight coils are formed at equal intervals in the circumferential direction on both the front coil sheet 22a and the back coil sheet 22b. Since each of the eight coils of the front coil sheet 22a is connected to each of the eight coils of the back coil sheet 22b by through holes, the fixed coil sheet 22 has eight coils. Can be considered.

  As shown in FIG. 2, the stationary coil sheet 22 includes a unit primary coil group 23 and a unit output coil group 24. The unit primary coil group 23 includes four primary coils 23a, 23b, 23c, and 23d adjacent to each other among the eight coils. The unit output coil group 24 includes a first output coil group 25 and a second output coil group 26. The first output coil group 25 includes output coils 25a and 25b, and the second output coil group 26 includes an output coil 26a. , 26b. Hereinafter, when these eight coils are described by distinguishing between the coil formed on the front surface coil sheet 22a and the coil formed on the back surface coil sheet 22b, the coil of the front surface coil sheet 22a is referred to as a front side coil, The coil of the back surface coil sheet 22b is referred to as the back surface side.

  The output coils 25a and 25b are connected in series. The front-side output coil 25a has a left spiral pattern from the outside toward the inside, and is connected to the inner end of the back-side output coil 25a by a through hole T1 at the inner end. The back side output coil 25a has a left spiral pattern from the inside toward the outside, and is connected to the outside end of the surface side output coil 25b by a through hole T2 at the outside end.

  The front-side output coil 25b has a right spiral pattern from the outside to the inside, and is connected to the inside end of the back-side output coil 25b by a through hole T3 at the inside end. The back side output coil 25b has a right spiral pattern from the inside toward the outside. Thus, the winding direction of the output coil 25a and the output coil 25b is opposite when viewed from the A direction, and the direction of current flow is always opposite. The outer end of the output coil 25a on the front surface side and the outer end of the output coil 25b on the rear surface side are connected to output terminals 25c and 25d for taking out the output to the outside of the angle detection device 10, respectively. Hereinafter, the voltage between the output terminals 25c and 25d is referred to as a first output voltage.

  Also in the second output coil group 26, the output coils 26a and 26b are connected in series. The front side output coil 26a has a right spiral pattern from the outside to the inside, and is connected to the inner end of the output coil 26a on the back side by a through hole T4 at the inner end. The output coil 26a on the back side has a right spiral pattern from the inside toward the outside, and is connected to the outside end of the output coil 26b on the front side by a through hole T5 at the outside end.

  The output coil 26b on the front surface side has a right spiral pattern from the outside to the inside, and is connected to the inner end of the output coil 26b on the back surface side through a through hole T6 at the inner end. The back side output coil 26b has a right spiral pattern from the inside toward the outside. Thus, the winding direction of the output coil 26a and the output coil 26b is the same as seen from the A direction, and the current flowing direction is always the same. The outer end of the output coil 26a on the front surface side and the outer end of the output coil 26b on the rear surface side are connected to output terminals 26c and 26d for taking out the output to the outside of the angle detection device 10, respectively. Hereinafter, the voltage between the output terminals 26c and 26d is referred to as a second output voltage.

  In the unit primary coil group 23, the primary coils 23a, 23b, 23c, and 23d are connected in series. As shown in FIG. 2, the primary coil 23a on the front side has a left spiral pattern from the outside to the inside, and is connected to the inner end of the primary coil 23a on the back side by a through hole T7 at the inner end. The primary coil 23a on the back side has a left spiral pattern from the inside toward the outside, and is connected to the outside end of the surface side primary coil 23b by a through hole T8 at the outside end.

  The front-side primary coil 23b has a right spiral pattern from the outside to the inside, and is connected to the inside end of the back-side primary coil 23b by a through hole T9 at the inside end. The primary coil 23b on the back side has a right spiral pattern from the inside toward the outside, and is connected to the outside end of the surface side primary coil 23c through the through hole T10 at the outside end.

  The front-side primary coil 23c has a left spiral pattern from the outside to the inside, and is connected to the inside end of the back-side primary coil 23c by a through hole T11 at the inside end. The primary coil 23c on the back side is a left spiral pattern from the inside to the outside, and is connected to the outer peripheral end of the primary coil 23d on the front side by a through hole T12 at the outside end.

  The front-side primary coil 23d has a right spiral pattern from the outside to the inside, and is connected to the inside end of the back-side primary coil 23d by a through hole T13 at the inside end. The primary coil 23d on the back surface side has a right spiral pattern from the inside toward the outside. Thus, the winding directions of the primary coils 23a, 23b, 23c, and 23d are alternately reversed when viewed from the A direction, and the direction of current flow is always alternately reversed. The outer end of the primary coil 23a on the front surface side and the outer end of the primary coil 23d on the back surface side are respectively connected to input terminals 23e and 23f that are connected to the AC power supply 80 outside the angle detection device 10.

  In the present embodiment, the number of turns of the output coils 25a, 25b, 26a, and 26b and the primary coils 23a, 23b, 23c, and 23d is the same. However, the present invention is not limited to this. The number of turns of the output coils 25a, 25b, 26a, 26b and the primary coils 23a, 23b, 23c, 23d may be different. However, the number of turns of each of the output coils 25a, 25b, 26a, and 26b is preferably the same. Similarly, the number of turns of the primary coils 23a, 23b, 23c, and 23d should be the same.

  In the present embodiment, the primary coils 23a, 23b, 23c, and 23d are connected in series, but the present invention is not limited to this. The primary coils 23a, 23b, 23c, and 23d may be connected in parallel as long as a current in the same direction as that in the series connection flows. Further, series connection and parallel connection may be mixed. Since the energization current per primary coil can be increased by using the parallel connection, a large induced electromotive force can be generated in the secondary coil described later.

[Rotor structure]
FIG. 3 is an explanatory diagram showing the winding state of the coil of the rotating side coil sheet 32 when viewed from the direction A of FIG. In FIG. 3, the upper coil sheet is the front coil sheet 32a and the lower coil sheet is the back sheet 32b. As shown in FIG. 3, eight coils are formed on the surface coil sheet 32a at equal intervals in the circumferential direction. Each of the eight coils of the front coil sheet 32a is connected to the wiring pattern of the back sheet 32b through a through hole.

  As shown in FIG. 3, the rotating side coil sheet 32 includes two unit secondary coil groups 33. Each unit secondary coil group 33 includes four adjacent secondary coils 33a, 33b, 33c, and 33d. The secondary coils 33a, 33b, 33c, and 33d are insulated from each other, and the winding directions are opposite to each other. That is, the secondary coils 33a and 33c are left spiral patterns from the outside to the inside, and the secondary coils 33b and 33d are right spiral patterns from the outside to the inside. The coils with the same reference numerals are arranged at a position shifted by 180 ° in mechanical angle. This corresponds to a phase difference of 360 ° in electrical angle, and the reason will be described later.

  Hereinafter, when the two unit secondary coil groups 33 are described separately, they are referred to as unit secondary coil groups 33-1 and 33-2. Furthermore, when the secondary coils 33a, 33b, 33c, and 33d are described separately by identifying which of the unit secondary coil groups 33-1 and 33-2 is a coil, the unit secondary coil group 33- One secondary coil 33a, 33b, 33c, 33d is called secondary coil 33a-1, 33b-1, 33c-1, 33d-1, and secondary coil 33a, 33b of unit secondary coil group 33-2. 33c and 33d are referred to as secondary coils 33a-2, 33b-2, 33c-2, and 33d-2.

  In the present embodiment, secondary coils having the same reference numerals are connected. That is, the secondary coil 33a-1 and the secondary coil 33a-2 are connected. Similarly, the secondary coil 33b-1 and the secondary coil 33b-2, the secondary coil 33c-1 and the secondary coil 33c-2, and the secondary coil 33d-1 and the secondary coil 33d-2 are connected to each other. .

  Specifically, as shown in FIG. 3, the inner end of the secondary coil 33a-1 is connected to the inner end of the secondary coil 33a-2 via the through hole T14, the wiring H1, and the through hole T15. The outer end of the coil 33a-2 is connected to the outer end of the secondary coil 33a-1 through the through hole T16, the wiring H2, and the through hole T17. Similarly, the inner end of the secondary coil 33b-1 is connected to the inner end of the secondary coil 33b-2 via the through hole T18, the wiring H3, and the through hole T19, and the outer end of the secondary coil 33b-2 is a through hole. It is connected to the outer end of the secondary coil 33b-1 through the hole T20, the wiring H4, and the through hole T21. With this connection, the direction of the magnetic flux generated when the induced electromotive force is generated in one of the secondary coils 33a-1 and 33b-1, and the other secondary coil 33a-2 due to the current flowing by the induced electromotive force. , 33b-2, the direction of magnetic flux generated in the opposite direction. Hereinafter, such connection is referred to as reverse connection.

  On the other hand, the inner end of the secondary coil 33c-1 is connected to the outer end of the secondary coil 33c-2 via the through hole T22, the wiring H5, and the through hole T23, and the inner end of the secondary coil 33c-2 is a through hole. It is connected to the outer end of the secondary coil 33c-1 via T24, wiring H6, and through hole T25. Similarly, the inner end of the secondary coil 33d-1 is connected to the outer end of the secondary coil 33d-2 via the through hole T26, the wiring H7, and the through hole T27, and the inner end of the secondary coil 33d-2 is a through hole. It is connected to the outer end of the secondary coil 33d-1 through the hole T28, the wiring H8, and the through hole T29. When connected in this manner, the direction of the magnetic flux generated when the induced electromotive force is generated in one of the secondary coils 33c-1 and 33d-1, and the other secondary coil 33c-2 due to the current flowing by the induced electromotive force. , 33d-2 and the magnetic flux generated in the same direction. Hereinafter, such a connection is referred to as a positive connection.

  FIG. 4A shows a schematic diagram for visually explaining the positive connection. FIG. 4B is a schematic diagram for visually explaining the reverse connection. Hereinafter, an outline of the angle detection will be described, and the forward connection and the reverse connection will be described through this. Detailed explanation of angle detection will be described later. As shown in FIG. 4A, when an AC current is passed through the unit primary coil group 23 by the AC power supply 80, a magnetic flux φ1 is generated, and the direction of the magnetic flux φ1 at a certain moment is downward in FIG. 4A. At this time, an upward magnetic flux φ2 is generated in the secondary coil (the secondary coil constituting the unit secondary coil group 33-1 in FIG. 4A) facing the unit primary coil group 23, which is a direction that prevents the change of the magnetic flux φ1. Inductive electromotive force is generated. Using this induced electromotive force as drive power, a current flows through a secondary coil (in FIG. 4A, a secondary coil constituting the unit secondary coil group 33-2) facing the unit output coil group 24, thereby causing an upward magnetic flux. φ3 is generated. Due to the magnetic flux φ3, a downward magnetic flux φ4, which is a direction preventing the change of the magnetic flux φ3, is generated in the unit output coil group 24, and an induced electromotive force is generated. This induced electromotive force is taken out as an output voltage. In FIG. 4A, two secondary coils are connected so that the magnetic flux φ2 and the magnetic flux φ3 are in the same direction. Such a connection is a positive connection. On the other hand, in FIG. 4B, contrary to FIG. 4A, two secondary coils are connected so that the directions of the magnetic flux φ2 and the magnetic flux φ3 are reversed. Such a connection is a reverse connection.

[Operation of Angle Detection Device for Rotating Body and Angle Detection Method]
Next, the operation of the angle detection device 10 and the angle detection method will be described. The target shaft whose rotation angle is desired to be detected is connected to the shaft 40 so that the motor shaft and the shaft 40 rotate synchronously. An AC power source 80 is connected to the input terminals 23e and 23f, and an AC current is passed through the primary coils 23a, 23b, 23c, and 23d. When the shaft 40 is rotated by the rotation of the motor, the coils of the rotor 30 are also rotated, and the coils of the stator 20 facing the respective coils of the rotor 30 are changed with the rotation.

  When an alternating current is applied to the primary coils 23a, 23b, 23c, and 23d, the secondary coil of the rotor 30 that faces the primary coils 23a, 23b, 23c, and 23d, for example, the secondary coils 33a-1, 33b-1, and 33c. An induced electromotive force is generated in each of −1 and 33d−1. Then, the induced electromotive force is used as driving power for the secondary coils 33a-2, 33b-2, 33c-2, 33d-2 connected to the secondary coils 33a-1, 33b-1, 33c-1, 33d-1. Alternating current flows through each of them. Due to this alternating current, an induced electromotive force is generated in the output coils 25a, 25b, 26a, and 26b of the unit output coil group 24 facing the secondary coils 33a-2, 33b-2, 33c-2, and 33d-2. This induced electromotive force is taken out from the output terminals 25c, 25d, 26c, and 26d as an output voltage.

  In the above description, the secondary coils facing the primary coils 23a, 23b, 23c, and 23d have been described as secondary coils 33a-1, 33b-1, 33c-1, and 33d-1, but the rotor 30 rotates. Therefore, as a matter of course, the secondary coils facing the primary coils 23a, 23b, 23c, and 23d change. For example, when the surface coil sheet 32a of FIG. 3 rotates counterclockwise, when it rotates 45 °, the primary coils 23a, 23b, 23c, 23d face the secondary coils 33b-1, 33c-1, 33d. −1, 33a-2. Further, when rotated 45 °, the secondary coils 33c-1, 33d-1, 33a-2, 33b-2 face the primary coils 23a, 23b, 23c, 23d.

  Thus, as the rotor 30 rotates, the secondary coils that oppose the primary coils 23a, 23b, 23c, and 23d and the opposing areas of the respective secondary coils (the areas where the respective primary coils and secondary coils overlap) ) Will change. In response to this change, the waveform of the first output voltage output from the output terminals 25c and 25d has a cosine wave shape, and the waveform of the second output voltage output from the output terminals 26c and 26d has a sine wave shape. That is, the first output voltage and the second output voltage have waveforms having the same amplitude and a phase shift of 90 °. Based on these two output voltages, the rotation angle of the shaft 40, that is, the rotation angle of the connected motor can be calculated.

  In the angle detection device 10 of the present embodiment, both power transmission from the unit primary coil group 23 to the unit secondary coil group 33 and power transmission from the unit secondary coil group 33 to the unit output coil group 24 are performed. Thus, since the output voltage changes according to the coil facing area, a larger amount of voltage change can be obtained with respect to the rotation of the rotor 30, and the S / N ratio can be improved. In addition, the rotation angle information can be converted into an output voltage by all the coils arranged in the rotor 30, and the rotation angle can be detected efficiently. Furthermore, since the output coil 25a and the output coil 26a are connected in the reverse winding direction, a push-pull structure can be formed, and the influence of noise due to an external magnetic field can be suppressed.

  This will be described in more detail below. Here, the rotation angle of the rotor 30 when the rotor 30 and the stator 20 are opposed to each other in the coil arrangement as shown in FIGS. 2 and 3 will be described as 0 °. When a positive voltage is applied to the primary coils 23a, 23b, 23c, and 23d, it is assumed that a magnetic flux φ1 upward in the drawing is generated in the primary coils 23a and 23c. At this time, since the winding directions of the primary coils 23b and 23d are opposite, a magnetic flux φ1 downward in the drawing is generated. As a result, a magnetic flux φ2 opposite to the magnetic flux φ1 is generated in the secondary coils 33a-1, 33b-1, 33c-1, and 33d-1 facing the primary coils 23a, 23b, 23c, and 23d. That is, a downward magnetic flux φ2 is generated in the secondary coils 33a-1 and 33c-1, and an upward magnetic flux φ2 is generated in the secondary coils 33b-1 and 33d-1. An induced electromotive force is generated with the generation of the magnetic flux φ2.

  Using the induced electromotive force of the secondary coils 33a-1, 33b-1, 33c-1, 33d-1 as drive power, current flows through the secondary coils 33a-2, 33b-2, 33c-2, 33d-2, Magnetic flux φ3 is generated. Since the secondary coil 33a-2 is reversely connected to the secondary coil 33a-1, an upward magnetic flux φ3 is generated in the secondary coil 33a-2. Similarly, a downward magnetic flux is generated in the secondary coil 33b-2. On the other hand, since the secondary coil 33c-2 is positively connected to the secondary coil 33c-1, a downward magnetic flux φ3 is generated in the secondary coil 33c-2. Similarly, an upward magnetic flux is generated in the secondary coil 33d-2.

  The magnetic flux φ3 generated in the secondary coils 33a-2, 33b-2, 33c-2, and 33d-2 generates a magnetic flux φ4 in the direction opposite to the direction of the magnetic flux φ3 in the output coils 25a, 25b, 26a, and 26b. That is, a downward magnetic flux φ4 is generated in the output coils 26a and 25b, and an upward magnetic flux φ4 is generated in the output coils 26b and 25a. An induced electromotive force is generated with the generation of the magnetic flux φ4.

  The sign of the output voltage due to the induced electromotive force of each of the output coils 25a, 25b, 26a, and 26b is determined by the direction of the magnetic flux φ4 and the winding direction of the coil. For the output coil 25a, the magnetic flux φ4 is upward, and the winding direction is a left spiral pattern from the outside to the inside as described above. This is the same as the state of the primary coils 23a and 23c. Since the voltage applied to the primary coils 23a and 23c is positive, it is assumed that a positive output voltage is generated in the output coil 25a. For the output coil 25b, the magnetic flux φ4 is downward and the winding direction is a right spiral pattern. This is opposite to the direction of the magnetic flux φ4 and the winding direction as compared with the output coil 25a. Accordingly, a current in the same direction as the output coil 25a flows through the output coil 25b, and a positive output voltage is generated. For the output coil 26a, the magnetic flux φ4 is downward and the winding direction is a right spiral pattern. This is opposite to the direction of the magnetic flux φ4 and the winding direction as compared with the output coil 25a. Therefore, a current in the same direction as the output coil 25a flows through the output coil 26a, and a positive output voltage is generated. For the output coil 26b, the magnetic flux φ4 is upward, and the winding direction is a right spiral pattern. Compared with the output coil 25a, the direction of the magnetic flux φ4 is the same and the winding direction is reversed. Therefore, a current in the direction opposite to that of the output coil 25a flows through the output coil 26b, and a negative output voltage is generated. FIG. 5 shows a table representing the positive / negative relationship between the applied voltage and the output voltage for each combination of the winding direction of the primary coil and the output coil and the connection method between the secondary coils (positive connection and reverse connection).

  Hereinafter, in order to quantify the output voltage, the positive output voltage is +1 and the negative output voltage is −1 for convenience. According to this, since the output coil 25a and the output coil 25b are connected in series, and a positive output voltage is generated in both, the first output voltage is +2. The output coil 26a and the output coil 26b are also connected in series. Since a positive output voltage is generated in the output coil 26a and a negative output voltage is generated in the output coil 26b, the voltage is canceled and the second output voltage is 0. Become. The above is the voltage when the rotation angle is 0 °, but when the rotor 30 rotates, if the rotation angle is every 45 °, the first output voltage and the second output voltage can be obtained in the same manner as described above. it can. FIG. 6 shows a table representing the first output voltage and the second output voltage for each rotation angle of 45 ° when the rotation-side coil sheet 32 is rotated counterclockwise from the state of FIG.

  When the rotation angle is 0 °, the primary coils 23a, 23b, 23c, and 23d and the secondary coils 33a-1, 33b-1, 33c-1, and 33d-1 are completely overlapped. The absolute value of the induced electromotive force generated in each of 25b, 26a, and 26b is maximized. Thereafter, as the rotor 30 rotates and the overlap between the primary coils 23a, 23b, 23c, and 23d and the secondary coils 33a, 33b, 33c, and 33d decreases, the induced electromotive force decreases, and the rotation angle 22.5 The absolute value of the induced electromotive force is minimized at °. Thereafter, the induced electromotive force increases, and the absolute value of the induced electromotive force is maximized again at a rotation angle of 45 °. Thereafter, the absolute value of the induced electromotive force repeats minimum and maximum every 22.5 °. FIG. 7 is a graph showing the change in the first output voltage when the table of FIG. 6 is visualized and the rotation angle is continuously changed from 0 ° to 180 °. FIG. 8 is a graph showing the change of the second output voltage when the table of FIG. 6 is visualized and the rotation angle is continuously changed from 0 ° to 180 °. The broken line in FIGS. 7 and 8 is the actual output voltage and the frequency is the applied AC frequency. The first output voltage and the second output voltage are peak values of the actual output voltage.

  As shown in FIGS. 7 and 8, the graph of the first output voltage is a cosine wave, the graph of the second output voltage is a sine wave, and the phase is shifted by 90 °. Based on these two output voltages, the rotation angle of the shaft 40, that is, the rotation angle of the connected motor can be calculated.

  As shown in FIGS. 7 and 8, the phase of both the first output voltage and the second output voltage is changed by 360 ° while the rotation angle is changed by 180 °. That is, a mechanical angle of 180 ° corresponds to an electrical angle of 360 °, and each of the two connected secondary coils is arranged so as to be shifted by an electrical angle of 360 °.

  In the present embodiment, the fixed-side coil sheet 22 and the rotating-side coil sheet 32 are formed as two-layer sheet coils with the insulating layers 22c and 32c interposed therebetween, but are not limited to two layers. Three or more layers may be used, or a single layer may be used. Moreover, in the rotation side coil sheet 32, although the coil was not formed in the back surface sheet 32b, although a wiring becomes somewhat complicated, you may form a coil. However, the number of turns of the coil of the back surface sheet 32b is smaller than the number of turns of the coil of the surface coil sheet 32a. Furthermore, instead of the sheet coil, the coil may be constituted by a coated enameled wire or the like.

  In the present embodiment, the gap between the stator 20 and the rotor 30 is provided along the axial direction (axial gap), but the present embodiment also applies to the angle detection device 10 having a gap (radial gap) in the radial direction. The configuration can be applied.

2. Second Embodiment Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. In the description of the following embodiment, the same reference numerals are given to the same components as those in the first embodiment, and the description of the same components will be omitted. The present embodiment is different from the first embodiment in that the number of coils formed on the stationary coil sheet 22 and the rotating coil sheet 32 is 16, and the other structures are the same. That is, the unit primary coil group 23, the unit output coil group 24, and the unit secondary coil group 33 are all arranged in a mechanical angle range of 90 °. FIG. 9 is a schematic diagram showing the fixed side coil sheet 22 of the angle detection device 10 according to the present embodiment. Similarly, the schematic diagram showing the rotation side coil sheet 32 is shown in FIG.

  As shown in FIG. 9, in the present embodiment, two unit primary coil groups 23 (the number of primary coils) are provided where one unit primary coil group 23 (the number of primary coils is 4) is arranged in the first embodiment. 8) are arranged adjacent to each other, and two unit output coil groups 24 (the total number of output coils is 8) are arranged where one unit output coil group 24 (the number of output coils is 4) is arranged. Adjacent to each other. In the present embodiment, the eight primary coils 23a, 23b, 23c, 23d, 23a, 23b, 23c, and 23d included in the two unit primary coil groups 23 are all connected in series. The winding direction is alternately reversed as in the first embodiment. The four output coils 25a, 25b, 25a, 25b of the first output coil group 25 included in the two unit output coil groups 24 are all connected in series, and the winding direction is reversed as in the first embodiment. Yes. The four output coils 26a, 26b, 26a, 26b of the second output coil group 26 are also connected in series, and the winding direction is the same as in the first embodiment.

  As shown in FIG. 10, in the first embodiment, one unit secondary coil group 33-1 (the number of secondary coils is 4) is arranged, but two unit secondary coil groups 33-1 (secondary coils) are arranged. A total of 8) coils are arranged adjacent to each other, and two unit secondary coil groups 33-2 are provided where one unit secondary coil group 33-2 (number of secondary coils is 4) is arranged. (The total number of secondary coils is 8) are arranged adjacent to each other. The four secondary coils 33a-1, 33b-1, 33c-1, and 33d-1 of the unit secondary coil group 33-1 are arranged at a position shifted by 180 ° in mechanical angle as in the first embodiment. The four secondary coils 33a-2, 33b-2, 33c-2, and 33d-2 of the secondary coil group 33-2 are respectively connected. The arrangement and winding direction of the secondary coils 33a, 33b, 33c, and 33d in the unit secondary coil group 33 and the connection method between the secondary coils (normal connection and reverse connection) are the same as those in the first embodiment. That is, in the present embodiment, eight closed circuits (circuits shown in FIGS. 4A and 4B) formed by connecting two secondary coils are formed.

  In this embodiment, when the rotation-side coil sheet 32 is rotated by 90 °, the phase of the output voltage changes as much as the rotation-side coil sheet 32 of the first embodiment is rotated by 180 °. That is, in the present embodiment, the mechanical angle of 90 ° corresponds to the electrical angle of 360 °, and each of the two connected secondary coils is arranged with a mechanical angle shifted by 180 °. ° Deviation.

  Even when the rotor 30 is rotated with the stationary coil sheet 22 shown in FIG. 9 and the rotating coil sheet 32 shown in FIG. 10 facing each other, the rotation angle of the shaft 40 is detected in the same manner as in the first embodiment. be able to.

3. Third Embodiment As shown in FIG. 11, in this embodiment, two unit primary coil groups 23 and two unit output coil groups 24 are arranged on the fixed-side coil sheet 22 as in the second embodiment. However, it differs from the second embodiment in that the unit primary coil group 23 and the unit output coil group 24 are alternately arranged every 90 °. That is, the two unit primary coil groups 23 are point-symmetric with respect to the center, and the two unit output coil groups 24 are also point-symmetric with respect to the center. In the present embodiment, the eight primary coils 23a, 23b, 23c, 23d, 23a, 23b, 23c, and 23d included in the two unit primary coil groups 23 are all connected in series. The winding direction is alternately reversed as in the first embodiment. The four output coils 25a, 25b, 25a, 25b of the first output coil group 25 included in the two unit output coil groups 24 are all connected in series, and the winding direction is reversed as in the first embodiment. Yes. The four output coils 26a, 26b, 26a, 26b of the second output coil group 26 are also connected in series, and the winding direction is the same as in the first embodiment.

  As shown in FIG. 12, two unit secondary coil groups 33-1 and two unit secondary coil groups 33-2 are arranged in the rotation side coil sheet 32 as in the second embodiment. The point from which unit secondary coil group 33-1 and unit secondary coil group 33-2 are alternately arranged for every 90 degrees differs from a 2nd embodiment. The four secondary coils 33a-1, 33b-1, 33c-1, 33d-1 of one unit secondary coil group 33-1 are four secondary coils of one adjacent unit secondary coil group 33-2. 33a-2, 33b-2, 33c-2, and 33d-2, respectively. That is, each of the two connected secondary coils is shifted by 90 ° in mechanical angle. The arrangement and winding direction of the secondary coils 33a, 33b, 33c, and 33d in the unit secondary coil group 33 and the connection method between the secondary coils (normal connection and reverse connection) are the same as those in the first embodiment. That is, in the present embodiment, eight closed circuits (circuits shown in FIGS. 4A and 4B) formed by connecting two secondary coils are formed.

  Also in this embodiment, when the rotation side coil sheet 32 is rotated by 90 °, the phase of the output voltage changes as much as the rotation side coil sheet 32 of the first embodiment is rotated by 180 °. That is, in the present embodiment, the mechanical angle of 90 ° corresponds to the electrical angle of 360 °, and each of the two connected secondary coils is arranged with a mechanical angle of 90 ° shifted. ° Deviation.

  Even when the rotor 30 is rotated with the stationary coil sheet 22 shown in FIG. 11 and the rotating coil sheet 32 shown in FIG. 12 facing each other, the rotation angle of the shaft 40 is detected in the same manner as in the first embodiment. be able to.

  In the second and third embodiments, the total number of coils formed on the stationary coil sheet 22 and the rotating coil sheet 32 is 16, but the present invention is not limited to this. If the total number of coils is a multiple of 8, it may be more than 16.

  The present invention can be used in an angle detection device for a rotating body.

DESCRIPTION OF SYMBOLS 10 Rotating body angle detection apparatus 20 Stator 22c Insulating layer 23 Unit primary coil group 23a, 23b, 23c, 23d Primary coil 24 Unit output coil group 25a, 25b Output coil 26a, 26b Output coil 30 Rotor 33 Unit secondary coil Group 33a, 33b, 33c, 33d Secondary coil 40 axis

Claims (2)

The axis,
A rotor disposed coaxially with the shaft and rotating integrally with the shaft;
Comprising the rotor and a stator disposed opposite to the coaxial core via a gap,
The stator includes two output coils arranged adjacent to each other in the circumferential direction and connected in series with opposite winding directions, and two output coils arranged further adjacent to each other in the circumferential direction and connected in series with the same winding direction. The same number of unit output coil groups as the number of unit output coil groups, including one or more unit output coil groups including four primary coils arranged adjacent to each other in the circumferential direction and connected in opposite winding directions,
The rotor includes a unit secondary coil group including four secondary coils arranged adjacent to each other in the circumferential direction and wound in opposite directions and insulated from the unit output coil group and the unit primary coil group. With the same number,
Each of the secondary coils of one unit secondary coil group has the same winding direction among the secondary coils of another unit secondary coil group and has an electrical angle that is an integral multiple of a 360 ° phase difference. Connected to the secondary coil arranged in position,
When a current flows through each of the secondary coils of one unit secondary coil group due to the connection, the direction of the current flowing through each of the secondary coils and the current flowing through each of the connected secondary coils The direction of the is the same direction and the opposite direction is continuous in two adjacent units,
During the rotation of the rotor, an angle detection device for a rotating body, one of the connected secondary coils facing the primary coil and the other facing the output coil.   The gap between the stator and the rotor has an axial direction, and all the output coils and all the primary coils are formed in multiple layers with an insulating layer interposed therebetween, and the output coil 2. The angle detection device for a rotating body according to claim 1, wherein each of the primary coils is wound so that coils of all layers are connected in series and current flows in the same direction.

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