JP5640908B2 - Rotation angle detector and actuator using the same - Google Patents

Description

  The present invention relates to a rotation angle detection device that detects a rotation angle of a rotating body and an actuator using the rotation angle detection device.

  For example, a rotary encoder is used to detect the rotation angle of the rotating body. There are two types of rotary encoders: an absolute method and an incremental method. A rotation angle detection device including an absolute rotary encoder can detect an absolute rotation position of a rotating body. A rotation angle detection device including an incremental rotary encoder can detect a rotation angle relative to a rotation start position of a rotating body.

  Examples of the rotary encoder include an optical type and a magnetic type. The optical rotary encoder applies light to, for example, a slit disk that rotates together with the rotating body, and generates a pulse signal synchronized with the rotation of the rotating body based on the light that has passed through the slit disk. A magnetic rotary encoder causes a magnetic sensor to face, for example, a magnetic disk that rotates together with a rotating body, and generates a pulse signal synchronized with the rotation of the rotating body based on the strength of a magnetic field read by the magnetic sensor.

  Patent Document 1 describes a rotation angle detection device including a magnetic rotary encoder. The rotary encoder of Patent Document 1 has two Hall ICs. One Hall IC is arranged so as to be shifted in the circumferential direction with respect to the other Hall IC. As a result, the pulse signal output from one Hall IC is out of phase with the pulse signal output from the other Hall IC. The rotation angle detection device detects the rotation angle of the rotating body by counting the edges of the pulse signals output from one and the other Hall ICs.

JP 2009-112151 A

  In recent years, rotation angle detection devices have been required to reduce the number of parts in order to reduce the size or reduce the number of assembly steps. In the case of a magnetic rotary encoder as in Patent Document 1, it is conceivable to reduce the number of Hall ICs by 1 while maintaining the resolution by doubling the number of magnetizations of the magnetic disk. However, it is difficult to increase the number of magnetizations without changing the size of the magnetic disk. Even if the number of magnetizations of the magnetic disk can be increased, the magnetic flux density required for outputting the pulse signal cannot be obtained.

In the case of an optical rotary encoder, it is conceivable to reduce the number of light receiving elements such as phototransistors by one while maintaining the resolution by doubling the number of slits in the slit disk. However, it is difficult to increase the number of slits without changing the size of the slit disk.
The present invention has been made in view of the above-described problems, and an object thereof is to provide a rotation angle detection device with a small number of parts and an actuator using the rotation angle detection device.

  In the first aspect of the present invention, the rotation angle detection device includes a transmission unit, a reception unit, and a control unit. The transmitter is rotatable with the rotating body and generates a magnetic field or light. The receiver receives a magnetic field or light generated by the transmitter and outputs a pulse signal synchronized with the rotation of the rotating body. The control unit generates one or a plurality of virtual pulse signals out of phase with respect to the pulse signal, and counts the number of edges of the pulse signal and the virtual pulse signal. The control unit detects the rotation angle of the rotating body based on the number of edges of the pulse signal and the virtual pulse signal.

The “pulse signal edge” refers to a portion of the pulse signal where the output changes. The “rising edge of the pulse signal” refers to a portion where the output of the pulse signal changes from a low level to a high level. The “falling edge of the pulse signal” refers to a portion where the output of the pulse signal changes from a high level to a low level.
A control part counts the continuous 1st rising edge, falling edge, and 2nd rising edge among pulse signals. The control unit calculates an on-time from the time point of the first rising edge of the pulse signal to the time point of the falling edge, and a time obtained by multiplying the on-time from the time point of the falling edge of the pulse signal by a predetermined time ratio. When elapses, the falling edge of the virtual pulse signal is counted. The control unit calculates an off time from the counting time of the falling edge of the pulse signal to the counting time of the second rising edge, and multiplies the off time from the counting time of the second rising edge of the pulse signal by a predetermined time ratio. When the time has elapsed, the rising edges of the virtual pulse signal are counted.

  With this configuration, the rotation angle can be detected for a single receiver using a plurality of pulse signals synchronized with the rotation of the rotating body. For this reason, when the number of receiving units such as Hall ICs which are two in the past is reduced by one, a resolution equal to or higher than that in the conventional case can be obtained. That is, it is possible to reduce the number of receiving units while maintaining the resolution. As a result, a rotation angle detection device with a small number of parts can be obtained.

In the invention described in 請 Motomeko 2, the predetermined time ratio is 0.5.

According to a third aspect of the present invention, the rotation angle detection device includes a magnetic rotary encoder that includes a transmission unit composed of a multipolar magnet and a reception unit composed of a magnetic sensor. The transmitter is configured so that the N poles and the S poles are alternately arranged in the circumferential direction, and the circumferential interval between the N poles that are continuous in the circumferential direction and the circumferential interval between the S poles that are continuous in the circumferential direction are equal. Configured. According to this, when it is difficult to increase the number of magnetic poles without changing the size of the multipolar magnet, the rotation angle detection device can be configured in a small space.

In the invention according to claim 4 , the magnetic poles of the multipolar magnet constituting the transmitter are arranged at equal intervals in the circumferential direction. According to this, the rotation angle of the rotating body can be detected at equal intervals.
In the invention according to claim 5 , the rotation angle detection device is applied to an actuator. The actuator includes a motor including a stator and a rotor, and a rotary encoder configured by the rotation angle detection device according to claims 1 to 5 and detecting a rotation angle of the rotor of the motor. According to this, the rotation angle detection device can be configured in a small space when there is a restriction on the space for mounting the actuator.

It is a perspective view which shows the structure of the shift-by-wire system provided with the rotation angle detection apparatus by 1st Embodiment of this invention. It is a longitudinal cross-sectional view of the actuator of FIG. FIG. 3 is a view of a ring gear, a planetary gear, and a drive gear of the actuator of FIG. 2 as viewed from the direction of an arrow Y in FIG. 2. FIG. 3 is a view of a rear housing of the actuator of FIG. 2, a stator of a motor, and a rotary encoder as viewed from the direction of an arrow Y in FIG. 2. FIG. 3 is a perspective view schematically showing a drive shaft, a ring gear, and a planetary gear of the actuator of FIG. 2. It is a figure which shows the magnet of the rotary encoder of FIG. 2, Comprising: (a) Front view of magnet, (b) VIb-VIb sectional view taken on the line. It is a time chart figure which shows the pulse signal and virtual pulse signal which the rotation angle detection apparatus by 1st Embodiment of this invention processes. It is a flowchart figure which shows the control action of the rotation angle detection apparatus by 1st Embodiment of this invention. It is a time chart figure which shows the pulse signal and virtual pulse signal which the rotation angle detection apparatus by 2nd Embodiment of this invention processes. It is a time chart figure which shows the pulse signal and virtual pulse signal which the rotation angle detection apparatus by 3rd Embodiment of this invention processes. It is a figure which shows the magnet of the rotation angle detection apparatus by 4th Embodiment of this invention, Comprising: (a) Front view of magnet, (b) It is XIb-XIb sectional view taken on the line. It is a time chart figure which shows the pulse signal and virtual pulse signal which the rotation angle detection apparatus by 4th Embodiment of this invention processes.

Hereinafter, rotation angle detection devices according to a plurality of embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 shows a shift-by-wire system to which the rotation angle detection device according to the first embodiment of the present invention is applied. The shift-by-wire system 7 operates the actuator 1 according to the operation position of the select lever operated by the driver to switch the shift range of the vehicle automatic transmission (not shown). The shift-by-wire system 7 is a by-wire system in which the select lever and the shift actuator 1 are electrically connected via a wire (electric wire).

  The planetary gear type transmission employed in the vehicle automatic transmission according to the first embodiment uses a hydraulic clutch to engage each rotary element of a plurality of planetary gear devices provided between input and output members with other members. The gear position and shift range are switched by control. A manual control valve 70 serving as a range switching valve is provided in a hydraulic control device that supplies hydraulic oil having a predetermined pressure to the hydraulic clutch. The manual valve 70 includes a valve member 701 that is accommodated in the valve body 700 so as to be movable in the axial direction, and the valve member 701 moves in the axial direction to switch an oil passage in the hydraulic control device to change the transmission. Change the shift range. In the shift range of the transmission, a D range for forward travel, an R range for reverse travel, a P range for parking, and an N range for power cutoff are set.

The shift-by-wire system 7 includes a shift actuator 1, a control rod 72, a detent mechanism 73, a parking lock mechanism 74, and an electronic control unit 71 (hereinafter referred to as “ECU”).
As shown in FIGS. 2 to 4, the shift actuator 1 includes a motor 2, a cycloid reduction part 3, a parallel shaft gear reduction part 4, and an output shaft 5 in an outer member 6. The outer member 6 includes a front housing 60, a middle housing 61 and a rear housing 62.

The motor 2 is composed of a switched reluctance motor (SR motor) and includes a rotor 20 and a stator 21.
The rotor 20 includes a drive shaft 200 and a rotor core 201. The drive shaft 200 is rotatably supported by the rear housing 62 and the front housing 60. Between the one end portion 200a and the other end portion 200b of the drive shaft 200, there is a large diameter portion 200c and an eccentric portion 200d having an eccentric shaft φ3 that is eccentric with respect to the first shaft φ1 of the one end portion 200a and the other end portion 200b. Is provided. The rotor core 201 is fixed to the outer wall of the large diameter portion 200c of the drive shaft 200. The rotor core 201 forms a plurality of salient poles (not shown) that protrude outward in the radial direction every 45 degrees in the circumferential direction.

  The stator 21 is fixed to the inner wall of the rear housing 62 in the radially outward direction of the rotor 20. The stator 21 includes a stator core 210 and a coil 211. The stator core 210 forms a plurality of stator teeth (not shown) that protrude in the radially inward direction every 30 degrees in the circumferential direction. Coil 211 includes a U-phase coil, a V-phase coil, and a W-phase coil that are wound around each stator tooth.

  A wiring member 622 from the motor 2 and a rotary encoder 75 described later is embedded in the rear housing 62. The wiring member 622 extends to the connector 623 formed by the rear housing 62. The motor 2 and the rotary encoder 75 are electrically connected to the ECU 71 by connecting a connector (not shown) that accommodates wiring from the ECU 71 to the connector 623.

The cycloid reduction unit 3 is a kind of planetary gear reducer, and includes a ring gear 30 and a planetary gear 31.
The ring gear 30 is an annular internal gear arranged coaxially with the first shaft φ1. The ring gear 30 is fixed to the inner wall of the middle housing 61 in the radially outward direction of the eccentric part 200 d of the drive shaft 200.
The planetary gear 31 is an external gear that is arranged coaxially with the eccentric shaft φ <b> 3 and meshes with the ring gear 30. The planetary gear 31 is supported by a bearing 82 fitted to the outer wall of the eccentric portion 200d of the drive shaft 200 so as to be capable of rotating about the eccentric shaft φ3 and revolving around the first shaft φ1. The planetary gear 31 forms a plurality of torque transmission protrusions 310 protruding toward the drive gear 40 at equal intervals in the circumferential direction on a concentric circle of the eccentric shaft φ3. The torque transmission protrusion 310 functions as a rotation transmission means for transmitting the rotation component of the planetary gear 31 to the drive gear 40 together with a torque transmission hole 402 described later.

The parallel shaft gear reduction unit 4 includes a drive gear 40 and a driven gear 41.
The drive gear 40 is an external gear arranged coaxially with the first shaft φ1. The drive gear 40 is rotatably supported by a bearing 83 that fits into the front housing 60. The drive gear 40 has a plurality of torque transmission holes 402 into which the torque transmission protrusions 310 of the planetary gear 31 are loosely fitted. The torque transmission holes 402 are through holes formed at equal intervals in the circumferential direction on the concentric circle of the first shaft φ1, and constitute rotation transmission means together with the torque transmission holes 402. The drive gear 40 is coupled to the planetary gear 31 so that torque can be transmitted by engaging the torque transmission protrusion 310 and the torque transmission hole 402.
The driven gear 41 is a fan-shaped external gear arranged coaxially with a second shaft φ2 parallel to the first shaft φ1.

  The output shaft 5 is rotatably supported around the second axis φ2 by a bearing 84 fitted to the front housing 60. A driven gear 41 is fixed to the outer wall of the output shaft 5. The control rod 72 is fitted into the fitting hole 510 of the output shaft 5. By this fitting, the output shaft 5 and the control rod 72 are connected so as to transmit torque.

  In the shift actuator 1 configured as described above, when the ECU 71 switches the energization to the coil 211 of the motor 2 in the order of the U-phase coil, the V-phase coil, and the W-phase coil, the rotor 20 rotates in one direction. When the ECU 71 switches the energization of the coil 211 of the motor 2 in the order of the W-phase coil, the V-phase coil, and the U-phase coil, the rotor 20 rotates in the other direction. Each time energization of the U-phase coil, V-phase coil, and W-phase coil is completed, the rotor 20 rotates 45 degrees.

  When the motor 2 operates and the drive shaft 200 rotates about the first axis φ1, the planetary gear 31 of the cycloid reduction unit 3 revolves around the first axis φ1 as shown by the arrow b in FIG. As shown by c, it rotates around the eccentric shaft φ3. Each time the drive shaft 200 makes one rotation around the first axis φ1, the planetary gear 31 rotates by a predetermined angle corresponding to the difference in the number of teeth between the planetary gear 31 and the ring gear 30 in the direction opposite to the revolution direction of the planetary gear 31. The rotation speed of the planetary gear 31 is greatly reduced as compared with the rotation speed of the drive shaft 200 around the first axis φ1. The cycloid reduction unit 3 decelerates the rotation input from the motor 2 and outputs it to the drive gear 40.

When the rotation component of the planetary gear 31 is input to the drive gear 40 via the torque transmission protrusion 310 and the torque transmission hole 402, the parallel shaft gear reduction unit 4 decelerates the rotation of the drive gear 40 from the driven gear 41. Output to the output shaft 5. The output shaft 5 outputs the rotation input from the driven gear 41 to the control rod 72.
The shift actuator 1 rotates the control rod 72 to the rotation position corresponding to the shift range selected by the select lever.

The shift actuator 1 incorporates a rotary encoder 75 that constitutes a rotation angle detection device together with the ECU 71.
The rotary encoder 75 includes a magnet 750, a Hall IC 751, and an encoder board 752. As shown in FIG. 6, the magnet 750 serving as the “transmitter, magnetic member” is a multipolar magnet in which N poles and S poles are alternately magnetized in the circumferential direction. In the magnet 750, the magnetic poles are arranged at equal intervals in the circumferential direction. In the first embodiment, the number of magnetizations of the N pole and the S pole of the magnet 750 is 24, for example. That is, one cycle is 15 °. The magnet 750 is fixed to the rotor 20 as a “rotating body”.

The Hall IC 751 and the encoder board 752 correspond to a “reception unit”. These Hall IC 751 and encoder board 752 are fixed to the inner bottom wall of the rear housing 62. The Hall IC 751 as a “magnetic sensor” has a Hall element. This Hall element can detect the direction and magnitude of the magnetic field generated by the magnet 750.
The encoder board 752 includes a substrate on which the Hall IC 751 is mounted. The encoder board 752 generates a pulse signal synchronized with the rotation of the rotor 20 based on the pulsed electric signal output from the Hall IC 751. The encoder board 752 outputs the pulse signal to the ECU 71 as a “control unit”. In the first embodiment, 24 pulse signals are output during one rotation of the rotor 20.

  A detent plate 730 of a detent mechanism 73 is fixed to the control rod 72. The rotation output from the shift actuator 1 is transmitted to the detent plate 730 via the control rod 72.

The detent mechanism 73 includes a detent plate 730 and a detent spring 733.
The detent plate 730 is a plate-like member that protrudes radially outward from the control rod 72 and has a plurality of engaging grooves 731 on the protruding tip surface. The detent plate 730 forms an engagement protrusion 732 that protrudes in a direction parallel to the axial direction of the control rod 72. The engagement protrusion 732 can engage with the valve member 701 of the manual valve 70 in the axial direction.

  The detent spring 733 is a cantilevered spring plate whose base end is fixed to the valve body 700 of the manual valve 70. A roller 734 is provided at the tip of the detent spring 733 that is divided into two branches. The rotational positions of the detent plate 730 and the control rod 72 are fixed when the roller 734 of the detent spring 733 engages with any one of the plurality of engagement grooves 731 of the detent plate 730. The detent mechanism 73 functions as a detent means for the control rod 72.

The parking lock mechanism 74 includes a park rod 740, a cam member 741, a parking lock pole 742, and a parking gear 743.
A proximal end portion of the park rod 740 is connected to the detent plate 730. The tip of the park rod 740 reciprocates in a direction substantially parallel to the axial direction of the parking gear 743 as the detent plate 730 rotates. The cam member 741 reciprocates together with the tip of the park rod 740. The parking lock pole 742 is provided with a meshing protrusion 742 a that can approach and separate from the parking gear 743. When the cam member 741 is inserted between the distal end portion of the parking lock pole 742 and the pedestal 744, the meshing protrusion 742 a moves toward the parking gear 743 and meshes with the parking gear 743. Due to this meshing, the parking gear 743 fixes the output shaft of the stepped transmission so that it cannot rotate.

  The ECU 71 is composed of a microcomputer having a CPU, a ROM, a RAM, and the like (not shown). The ECU 71 is electrically connected to a lever position sensor, a rotary encoder 75 and an inhibitor switch 76 (not shown). The lever position sensor outputs an electric signal corresponding to the operation position of the select lever to the ECU 71. The rotary encoder 75 outputs a pulse signal synchronized with the rotation of the rotor 20 of the motor 2 of the shift actuator 1 to the ECU 71. The inhibitor switch 76 outputs an electrical signal corresponding to the absolute rotational position of the control rod 72 to the ECU 71. The inhibitor switch 76 is composed of, for example, a potentiometer.

  The ECU 71 controls the shift actuator 1 in accordance with a predetermined control program recorded in the ROM based on each input signal. Specifically, the ECU 71 calculates a target rotation angle of the control rod 72 for switching to the designated shift range corresponding to the operation position of the select lever prior to operating the shift actuator 1. Then, the ECU 71 rotates the shift actuator 1 until the target rotation angle of the control rod 72 is obtained. In the first embodiment, the ECU 71 grasps the rotational position of the control rod 72 based on the electrical signal supplied from the inhibitor switch 76. Further, the ECU 71 grasps the rotation directions of the motor 2 and the control rod 72 based on the electrical signal supplied from the inhibitor switch 76.

  The shift-by-wire system 7 configured as described above outputs an operation command signal for the shift actuator 1 from the ECU 71 when the instruction shift range instructed by the select lever is changed. When the shift actuator 1 is operated according to the operation command signal, the control rod 72 and the detent plate 730 are rotated. When the valve member 701 engaged with the detent plate 730 is moved in the axial direction by the rotation, the manual valve 70 is operated to switch the shift range and the cam member 741 is moved in the axial direction. When the command shift range is the P range, the cam member 741 pushes up the parking lock pawl 742 so that the meshing protrusion 742a of the parking lock pawl 742 and the parking gear 743 are engaged, and the output shaft of the stepped transmission cannot be rotated. Fix it.

Next, the function of the ECU 71 for detecting the rotation angle will be described in detail.
The ECU 71 generates virtual pulse signals that are out of phase with respect to the pulse signals output from the rotary encoder 75, and counts the number of edges of these pulse signals and virtual pulse signals. Then, the rotation angle of the rotor 20 that is proportional to the counted number of edges is detected. The detection will be specifically described below.

FIG. 7 shows a pulse signal PS1 supplied to the ECU 71. In FIG. 7, the virtual pulse signal PS2 generated by the ECU 71 is indicated by a two-dot chain line.
The ECU 71 counts rising edges E1 and E3 and falling edges E2 and E4 of the pulse signal PS1. The ECU 71 calculates an ON time T1 from the counting time t1 of the rising edge E1 to the counting time t2 of the falling edge E2. The ECU 71 calculates an off time T2 from the count time t2 of the falling edge E2 to the count time t4 of the rising edge E3. The ECU 71 calculates an ON time T3 from the count time t4 of the rising edge E3 to the count time t6 of the falling edge E4.

  The ECU 71 counts the falling edge E5 of the virtual pulse signal PS2 when the half time {(T1) / 2} of the on-time T1 has elapsed from the counting time t2 of the falling edge E2. The ECU 71 counts the rising edge E6 of the virtual pulse signal PS2 when the half time {(T2) / 2} of the off time T2 has elapsed since the counting time t4 of the rising edge E3. The ECU 71 counts the falling edge E7 of the virtual pulse signal PS2 when the half time {(T3) / 2} of the on-time T3 has elapsed since the counting time t6 of the falling edge E4.

  The ECU 71 determines the pulse signals PS1 and PS2 based on the pulse signal PS1 detected by the Hall IC 751 and the virtual pulse signal PS2 generated from the on time T1, the off time T2, and the on time T3 between the edges of the pulse signal PS1. By counting the edges E1 to E7, the rotation angle of the rotor 20 is detected every 3.75 degrees, that is, every quarter period of 15 °.

  Next, the operation of the ECU 71 will be described with reference to FIG. FIG. 8 shows a processing flow related to the control operation of the ECU 71 for detecting the rotation angle. The series of processing shown in FIG. 8 is repeatedly executed until the control rod 72 rotates by the target rotation angle after the operation command signal for the shift actuator 1 is output from the ECU 71, for example. Whether or not the control rod 72 has rotated the target rotation angle is detected by, for example, the inhibitor switch 76.

  In step S1 of FIG. 8, the ECU 71 determines whether or not the count condition of the rising edge E1 of the pulse signal PS1 is satisfied. The ECU 71 determines that the count condition of the rising edge E1 is satisfied when the pulse signal PS1 indicates 1. If the count condition for the rising edge E1 is satisfied (step S1: YES), the process proceeds to step S2. On the other hand, when the counting condition of the rising edge E1 is not satisfied (step S1: NO), the ECU 71 determines that the motor 2 is not rotating and exits this routine.

In step S2, the ECU 71 counts the rising edge E1 of the pulse signal PS1.
In step S3, the ECU 71 determines whether or not the count condition of the falling edge E2 of the pulse signal PS1 is satisfied. The ECU 71 determines that the count condition of the falling edge E2 is satisfied when the pulse signal PS1 indicates 0. If the count condition for the falling edge E2 is satisfied (step S3: YES), the process proceeds to step S4. On the other hand, when the count condition of the falling edge E2 is not satisfied (step S3: NO), the ECU 71 exits this routine.

In step S4, the ECU 71 counts the falling edge E2 of the pulse signal PS1.
In step S5, the ECU 71 calculates an ON time T1 from the time point of the rising edge E1 to the time point of the falling edge E2.
In step S6, the ECU 71 counts the falling edge E5 of the virtual pulse signal PS2 when a time {(T1) / 2} that is half of the on-time T1 has elapsed from the time of counting of the falling edge E2.

  In step S7, the ECU 71 determines whether or not the count condition of the rising edge E3 of the pulse signal PS1 is satisfied. The ECU 71 determines that the count condition of the rising edge E3 is satisfied when the pulse signal PS1 indicates 1. If the count condition for the rising edge E3 is satisfied (step S7: YES), the process proceeds to step S7. On the other hand, when the count condition for the rising edge E3 is not satisfied (step S7: NO), the ECU 71 exits this routine.

In step S8, the ECU 71 counts the rising edge E3 of the pulse signal PS1.
In step S9, the ECU 71 calculates an off time T2 from the counting time of the falling edge E2 to the counting time of the rising edge E3.
In step S10, the ECU 71 counts the rising edge E6 of the virtual pulse signal PS2 when a time {(T2) / 2} that is half of the OFF time T2 has elapsed since the counting of the rising edge E3.

  In step S11, the ECU 71 determines whether the count condition for the falling edge E4 of the pulse signal PS1 is satisfied. The ECU 71 determines that the count condition of the falling edge E4 is satisfied when the pulse signal PS1 indicates 0. If the count condition for the falling edge E4 is satisfied (step S11: YES), the process proceeds to step S12. On the other hand, when the count condition of the falling edge E4 is not satisfied (step S11: NO), the ECU 71 exits this routine.

In step S12, the ECU 71 counts the rising edge E4 of the pulse signal PS1.
In step S13, the ECU 71 calculates an ON time T3 from the time point of the rising edge E3 to the time point of the falling edge E4.
In step S14, the ECU 71 counts the falling edge E7 of the virtual pulse signal PS2 when the half time {(T3) / 2} of the on-time T3 has elapsed since the counting of the falling edge E4, and exits this routine. .

As described above, in the first embodiment, the ECU 71 detects the pulse signal PS1 detected by the Hall IC 751 and the virtual pulse signal generated from the on time T1, the off time T2, and the on time T3 between the edges of the pulse signal PS1. The rotation angle of the rotor 20 is detected every 3.75 degrees by counting the edges E1 to E7 of the pulse signals PS1 and PS2 based on PS2.
In this configuration, the rotation angle can be detected for one Hall IC 751 using the two pulse signals PS1 and the virtual pulse signal PS2 synchronized with the rotation of the rotor 20. For this reason, when the number of Hall ICs, which has been two in the past, is reduced to one, a resolution equal to or higher than that in the past can be obtained. That is, it is possible to reduce the number of Hall ICs while maintaining the resolution. As a result, a rotation angle detection device with a small number of parts can be obtained.

In the first embodiment, the magnetic poles of the magnet 750 are arranged at equal intervals in the circumferential direction. According to this, the rotation angle of the rotating body can be detected at equal intervals.
In the first embodiment, the rotation angle detection device includes a magnetic rotary encoder 75 including a magnet 750, a Hall IC 751, and an encoder board 752. According to this, when it is difficult to increase the number of magnetic poles without changing the size of the magnet 750, the rotary encoder 75 can be configured in a small space.

  In the first embodiment, the rotation angle detection device is applied to the shift actuator 1 of the vehicle transmission and detects the rotation angle of the rotor 20 of the motor 2. According to this, the shift actuator 1 can be configured in a small space when there is a restriction on the vehicle mounting space.

(Second Embodiment)
As shown in FIG. 9, in the second embodiment, the ECU detects the virtual pulse signal PS3 when the off time T2 has elapsed from the count time t13 of the falling edge E5 of the virtual pulse signal PS3 while the motor rotates at a constant speed. The rising edge E8 is counted. Further, the ECU counts the falling edge E9 of the virtual pulse signal PS3 when the on-time T3 has elapsed from the counting time t15 of the rising edge E8 of the virtual pulse signal PS3. Thereby, the rotation angle of the rotor of the motor can be detected every 3.75 degrees, that is, every quarter period of 15 °. Furthermore, the control load can be reduced compared to the first embodiment.

(Third embodiment)
As shown in FIG. 10, in the third embodiment, the ECU generates two virtual pulse signals PS4 and PS5 that are out of phase with respect to the pulse signal PS1 output from the rotary encoder 75. The virtual pulse signal PS4 is out of phase with the pulse signal PS1 by 1/6 period. The virtual pulse signal PS5 is 2/6 cycles out of phase with the pulse signal PS1.

  The ECU counts the falling edge E10 of the virtual pulse signal PS4 when the time {(T1) / 3} of 1/3 of the on-time T1 has elapsed from the counting time t22 of the falling edge E2 of the pulse signal PS1. The ECU counts the rising edge E11 of the virtual pulse signal PS4 when the time {(T2) / 3} of 1/3 of the off time T2 has elapsed from the counting time t25 of the rising edge E3 of the pulse signal PS1. The ECU counts the falling edge E12 of the virtual pulse signal PS4 when a time {(T3) / 3} of 1/3 of the on-time T3 has elapsed from the counting time t28 of the falling edge E4 of the pulse signal PS1.

  The ECU counts the falling edge E13 of the virtual pulse signal PS5 when a time {2 (T1) / 3} of 2/3 of the on-time T1 has elapsed from the counting time t22 of the falling edge E2 of the pulse signal PS1. The ECU counts the rising edge E14 of the virtual pulse signal PS5 when a time {2 (T2) / 3} of 2/3 of the off time T2 has elapsed from the counting time t25 of the rising edge E3 of the pulse signal PS1. The ECU counts the falling edge E15 of the virtual pulse signal PS5 when a time {2 (T3) / 3} of 2/3 of the on-time T3 has elapsed from the counting time t28 of the falling edge E4 of the pulse signal PS1.

  The ECU determines each pulse signal PS1 based on the pulse signal PS1 detected by the Hall IC 751 and the virtual pulse signals PS4 and PS5 generated from the on time T1, the off time T2, and the on time T3 between the edges of the pulse signal PS1. By counting the edges E1 to E4 and E10 to E15 of PS4 and PS5, the rotation angle of the rotor of the motor can be detected every 2.5 degrees, that is, every 1/6 period of 15 °.

(Fourth embodiment)
FIG. 11 is a diagram showing a magnet 753 of the rotation angle detection device according to the fourth embodiment of the present invention. As shown in FIG. 11, the magnet 753 has N poles and S poles alternately arranged in the circumferential direction, and the circumferential interval between the N poles that are continuous in the circumferential direction and the S poles that are continuous in the circumferential direction. It is composed of multipolar magnets arranged so that circumferential intervals are equal. The magnet 753 is formed such that the S pole has a longer circumferential length than the N pole. In this embodiment, the circumferential length of the S pole is twice the circumferential length of the N pole.

  As shown in FIG. 12, in the fourth embodiment, when the motor rotates at a constant speed, the ON times T1 and T3 are halved compared to the OFF time T2. The ECU counts the falling edge E20 of the virtual pulse signal PS7 when the on-time T1 has elapsed from the counting time t32 of the falling edge E17 of the pulse signal PS6. The ECU counts the rising edge E21 of the virtual pulse signal PS7 when ¼ time {(T2) / 4} of the off time T2 has elapsed from the time t34 of the rising edge E18 of the pulse signal PS6. The ECU counts the falling edge E22 of the virtual pulse signal PS4 when the on-time T3 has elapsed from the counting time t36 of the falling edge E19 of the pulse signal PS6. Thereby, the rotation angle of the rotor of the motor can be detected every 2.5 degrees at the minimum.

(Other embodiments)
In another embodiment of the present invention, the ECU may generate three or more virtual pulse signals. As a result, the rotation angle can be detected more finely.
In another embodiment of the present invention, the magnet may be formed such that the N pole has a longer circumferential length than the S pole.
In another embodiment of the present invention, the number of magnetized magnets may not be 24.

In another embodiment of the present invention, for example, a magnetic sensor using a magnetoresistive element may be used instead of the Hall IC.
In another embodiment of the present invention, an optical rotary encoder may be used.
In another embodiment of the present invention, the rotation angle detection device may be used for a drive unit of, for example, another valve device of a vehicle, or may be used for a drive unit of another device such as an industrial robot or a machine tool. May be used.
In another embodiment of the present invention, a motor other than the SR motor may be employed.

  As mentioned above, this invention is not limited to the above-mentioned embodiment, In the range which does not deviate from the meaning, it can implement with a various form.

20 ... Rotor (rotating body)
71 ... ECU (control unit)
751 ... Magnet (transmitter)
752 ... Hall IC (receiver)
753 ... Encoder board (receiver)
E1, E3, E6, E8, E11, E14, E16, E18, E21 ... Rising edge (first rising edge, second rising edge)
E2, E4, E5, E7, E9, E10, E12, E13, E15, E17, E19, E20, E22 ... Falling edge PS1, PS6 ... Pulse signal PS2, PS3, PS4, PS5, PS7,.・ Virtual pulse signal

Claims (5)

A transmitter that can rotate with the rotating body and generates a magnetic field or light; and
A receiving unit that receives a magnetic field or light generated by the transmitting unit and outputs a pulse signal synchronized with the rotation of the rotating body;
Control for generating one or a plurality of virtual pulse signals out of phase with respect to the pulse signal, counting the number of edges of the pulse signal and the virtual pulse signal, and detecting a rotation angle of the rotating body proportional to the number of edges And
Equipped with a,
The controller is
Counting the first rising edge, falling edge and second rising edge of the pulse signal,
Calculating an on-time from the counting time of the first rising edge to the counting time of the falling edge;
Counting the falling edge of the virtual pulse signal when the time obtained by multiplying the on-time by a predetermined time ratio has elapsed from the counting time of the falling edge,
Calculating an off time from the falling edge counting time to the second rising edge counting time;
Rotation angle detecting apparatus according to claim count to Rukoto the rising edge of the virtual pulse signal when the time obtained by multiplying a predetermined time ratio to the off-time from the count time of the second rising edge has passed. The rotation angle detection device according to claim 1 , wherein the predetermined time ratio is 0.5. In the transmitter, the N poles and the S poles are alternately arranged in the circumferential direction, and the circumferential intervals between the N poles that are continuous in the circumferential direction and the circumferential intervals between the S poles that are continuous in the circumferential direction are equal. Composed of multipole magnets arranged as
The receiving unit, the rotation angle detecting apparatus according to claim 1 or 2, characterized in that they are composed of a magnetic sensor. The rotation angle detection device according to claim 3 , wherein the magnetic poles of the multipolar magnet constituting the transmission unit are arranged at equal intervals in the circumferential direction. A motor composed of a stator and a rotor;
Is constituted by a rotation angle detecting device according to claim 1-4, and a rotary encoder for detecting the rotation angle of the rotor of the motor,
An actuator comprising:

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