Shifting device

Abstract

To provide a shift device that can smoothly perform driving control of a motor even if an abnormality is detected at the time of shift switching.SOLUTION: A shift device 100 comprises: a shift switching member 21; a motor 11; a first drive system 17 including a first inverter 173 for outputting a voltage for driving the motor 11; a second drive system 18 provided separately from the first drive system 17, and including a second inverter 183 for outputting a voltage for driving the motor 11; and a positioning member 22. The shift device is constituted so as to switch a shift position by driving the motor 11 with the voltages outputted from both the first drive system 17 and the second drive system 18.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a shifting device, and more particularly to a shifting device including a shifting transition member including a plurality of valleys. [Background technology]

[0002] 2. Description of the Related Art A shift device including a shift switching member that includes a plurality of valleys is known in the art (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a shift range switching device including a shift switching member including a plurality of valleys. The shift range switching device includes a motor, a detent plate, a detent spring, a first switching element, a first system, a second switching element, a second system, and a control unit. The detent plate is a shift switching means that is driven by the motor to switch the shift ranges (P position, N position, R position, and D position). The detent spring is configured to fix the shift range of the detent plate.

[0004] The control unit of the above-mentioned Patent Document 1 is configured to perform control to switch the energization state to the coils U1, V1, and W1 of the first system by switching on and off the first switching element. The control unit is configured to perform control to switch the energization state to the coils U2, V2, and W2 of the second system by switching on and off the second switching element. In this way, in the shift range switching device, the motor can be driven only by controlling the energization of the coils U1, V1, and W1 of the first system or only by controlling the energization of the coils U2, V2, and W2 of the second system. The control unit is configured to perform control to drive the motor while feeding only the coils U1, V1, and W1 of the first system and stopping the feeding of the coils U2, V2, and W2 of the second system during normal operation.

[0005] Here, in the shift range switching device of the above-mentioned Patent Document 1, even if an abnormality occurs in the first system during shift switching, the drive control of the motor can be continued using the second system. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2009-8153 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the shift range switching device of the above Patent Document 1, although it is not specified in Patent Document 1, it is considered that the control unit needs to take measures (fail-safe) such as stopping the motor based on the detection of an abnormality in the first system during shift switching, and then transfer drive control of the motor to the second system. In this case, the control unit will perform drive control of the motor intermittently due to the transfer of drive control after the above-mentioned measures are taken. For this reason, it is considered that the shift range switching device of the above Patent Document 1 has a problem in that it is difficult to smoothly perform drive control of the motor when an abnormality is detected during shift switching.

[0008] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a shift device that is capable of smoothly controlling the drive of a motor even when an abnormality is detected during shift switching. [Means for solving the problem]

[0009] In order to achieve the above object, a shift device in one aspect of the present invention includes a shift switching member including a plurality of valleys corresponding to a shift position, a rotor and a stator, a motor for driving the shift switching member, a first drive system including a first inverter that outputs a voltage for driving the motor, a second drive system provided separately from the first drive system and including a second inverter that outputs a voltage for driving the motor, and a positioning member for establishing a shift position when the positioning member is fitted into any of the plurality of valleys of the shift switching member, and is configured to switch the shift position by driving the motor with voltages output from both the first drive system and the second drive system. When the positioning member reaches the bottom of each of the plurality of valleys, one of the first and second drive systems does not brake the motor, and the other drive system drives the motor to move the positioning member toward the bottom of the valley, and then, after a predetermined time has elapsed, the one drive system brakes the motor to stop the positioning member. .

[0010] In the shift device according to one aspect of the present invention, as described above, the shift position is changed by driving the motor with the voltage output from both the first drive system and the second drive system. In this way, if a failure is detected in either the first drive system or the second drive system during shift switching, a procedure (fail-safe) can be performed to stop the drive of the motor by the failed drive system while the drive of the motor by the normal drive system continues, so that the drive of the motor can be continued. As a result, when a failure is detected in either the first drive system or the second drive system during shift switching, the drive control of the motor is not performed intermittently, so that the drive control of the motor can be performed smoothly even if an abnormality is detected during shift switching. In addition, by driving the motor using both the first drive system and the second drive system, the power required to output the maximum torque of the motor can be distributed to each of the first drive system and the second drive system, so that the size of each of the first drive system and the second drive system can be suppressed compared to the case where the maximum torque of the motor is output using only one of the first drive system and the second drive system. In addition, the positioning member can be stopped near the bottom position of each of the multiple valleys that has been learned in advance in one drive system, while ensuring the drive time of the motor only by the other drive system, in which the determination that the positioning member has reached each of the multiple valleys is delayed. This makes it possible to suppress drive interference between the first drive system and the second drive system, and enables accurate shift switching.

[0011] In the shift device according to the above aspect, preferably, a first reach range within which it is determined that the first drive system has reached the bottom of each of the plurality of valleys, and a second reach range within which it is determined that the second drive system has reached the bottom of each of the plurality of valleys, based on a shift position acquired in advance; The positioning member is provided at each of the plurality of valleys. The bottom of the valley When reaching Based on the determination that the positioning member has reached one of the first reach range and the second reach range and has not reached the other, the drive system corresponding to one of the first reach range and the second reach range isMotor braking process The drive system corresponding to the other of the first and second reachable ranges drives a motor to move the positioning member toward the bottom of the valley, and the drive system corresponding to the first of the first and second reachable ranges is configured to brake the motor based on the lapse of a predetermined time after it is determined that the positioning member has reached one of the first reachable range and the second reachable range but has not reached the other of the first and second reachable ranges. .

[0012] With this configuration, it is possible to prevent one of the preceding drive systems from braking the motor before the other drive system, which has a delayed determination that the positioning member has reached each of the multiple valleys, determines that it has reached each of the multiple valleys, so that driving of the motor by the other drive system is not hindered.

[0013] In this case, it is preferable that the first inverter of the first drive system, which is the preceding drive system that is determined to have first reached each of the multiple valleys, is turned off, or the second inverter of the second drive system, which is the preceding drive system that is determined to have first reached each of the multiple valleys, is turned off so that no braking process is performed on the motor when the positioning member reaches each of the multiple valleys.

[0014] With this configuration, since power is not supplied to the motor from the preceding drive system that first determined that the positioning member has reached each of the valleys, the motor can be driven only by the other drive system that is delayed in determining that the positioning member has reached each of the valleys, and as a result, the motor can be driven as intended by the other delayed drive system.

[0015] In the above-mentioned shift device in which one of the preceding systems does not brake the motor, the preceding drive system which has first determined that the positioning member has reached each of the multiple valleys is preferably configured not to brake for a predetermined period of time when it reaches each of the multiple valleys.

[0016] By configuring in this manner, a predetermined amount of time can be secured during which the motor can be driven as intended by the other drive system, which is delayed in determining that the positioning member has reached each of the multiple valleys, so that the other drive system, which is delayed, can also reliably reach each of the multiple valleys.

[0017] In the above-mentioned shift device that does not brake for a predetermined time, preferably, the preceding drive system that has determined that the positioning member has reached each of the multiple valleys first is configured to brake the motor based on the passage of a predetermined time.

[0018] With this configuration, the positioning member can be stopped near the bottom position of each of the multiple valleys that have been learned in advance in one drive system, while ensuring the drive time of the motor only by the other drive system, in which the determination that the positioning member has reached each of the multiple valleys is delayed.This makes it possible to suppress drive interference between the first drive system and the second drive system and to perform shift switching accurately.

[0019] In the above-mentioned shift device in which one of the preceding systems does not brake the motor, preferably the one of the preceding systems which has first determined that the positioning member has reached each of the multiple valleys is configured not to perform braking processing of the motor when each of the multiple valleys is reached, based on the difference between the previously acquired shift position and the current position of the positioning member being within the position reach judgment range and the rotational speed of the motor being within the speed reach judgment range.

[0020] With this configuration, the positioning member can enter the position reach judgment range while the motor is decelerated sufficiently to prevent the positioning member from passing over the shift position, thereby preventing the positioning member from passing over the shift position due to failure to perform braking processing on the motor.

[0021] In the shift device according to the above aspect, the following configuration is also possible.

[0022] (Additional note 1) In other words, the first drive system, which is one of the preceding drive systems, is configured to brake the motor by turning on the switching element on the lower arm side of the first inverter of the first drive system based on the lapse of a predetermined time, or the second drive system, which is one of the preceding drive systems that has first determined that the positioning member has reached each of the multiple valleys, is configured to brake the motor by turning on the switching element on the lower arm side of the second inverter based on the lapse of a predetermined time.

[0023] With this configuration, the motor in the preceding drive system that is determined to have first reached each of the multiple valleys can be braked by a short brake, thereby allowing the motor to be stopped quickly.

[0024] (Additional note 2) In the shift device according to the above aspect, the shift device further includes a driving force transmission mechanism including an output shaft connected to the shift switching member and transmitting driving force from the motor to the shift switching member, a first motor rotation angle sensor and a second motor rotation angle sensor that measure the rotation angle of the motor, and a first output shaft sensor and a second output shaft sensor that measure the rotation angle of the output shaft, and is configured such that when switching the shift position, the motor is driven by the first drive system based on the measurement values ​​of the first motor rotation angle sensor and the output shaft sensor, and the motor is driven by the second drive system based on the measurement values ​​of the second motor rotation angle sensor and the second output shaft sensor.

[0025] With this configuration, the first drive system and the second drive system can each independently control the driving of the motor, so that even if an abnormality occurs in one of the first drive system and the second drive system, the driving control of the motor can be continued using the other drive system. [Brief description of the drawings]

[0026] [Figure 1] 1 is a perspective view showing a schematic overall configuration of a shift device according to an embodiment of the present invention; [Diagram 2]4A and 4B are diagrams illustrating a structure of a detent plate that constitutes the shift device according to the present embodiment. [Diagram 3] 2 is a cross-sectional view showing an actuator unit constituting the shift device according to the present embodiment. FIG. [Figure 4] 1 is a diagram showing the internal structure of a reduction mechanism in an actuator unit constituting a shift device according to the present embodiment with a gear housing removed from a main body. FIG. [Diagram 5] 4 is a diagram showing an engaged state (driving force transmittable state) of an intermediate gear in an actuator unit constituting the shift device according to the present embodiment. FIG. [Figure 6] 4 is a diagram showing an intermediate gear in an engaged state (driving force non-transmitting state) in the actuator unit constituting the shift device according to the present embodiment. FIG. [Figure 7] FIG. 2 is a block diagram showing a first drive system and a second drive system according to the present embodiment. [Figure 8] 4 is a diagram showing the relationship between the output value (output shaft angle) of the output shaft angle sensor, the output value (motor rotation angle) of the rotor rotation angle sensor, and the number of rotations of the motor in the shift device according to the present embodiment. FIG. [Figure 9] 13 is a diagram illustrating a state in which a roller portion of the shift device according to the present embodiment moves from an R position toward an N position. FIG. [Figure 10] 13 is a diagram illustrating a state in which a roller portion of the shift device according to the present embodiment moves from an N position toward an R position. FIG. [Figure 11] 5 is a diagram showing an example of a current supply pattern when a motor is driven by a first drive system and a second drive system of the shift device according to the present embodiment. FIG. [Figure 12] 10A and 10B are diagrams illustrating a state in which a detent spring moves at the bottom of each of a plurality of valleys in the shift device according to the present embodiment. [Figure 13] FIG. 4 is a diagram illustrating a state in which a first drive system of the shift device according to the present embodiment is in a free mode. [Figure 14]5A to 5C are diagrams illustrating a state in which a motor is braked by a first drive system and a second drive system of the shift device according to the present embodiment. [Figure 15] 5 is a flowchart showing a shift switching process by a first drive system in the shift device according to the present embodiment. [Figure 16] 5 is a flowchart showing a shift switching process by a second drive system in the shift device according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0028] The configuration of the shift device 100 will be described with reference to Figures 1 to 14. In this specification, the terms "rotation angle of the motor" and "rotation angle of the rotor" have the same meaning.

[0029] The shift device 100 is mounted on a vehicle such as an automobile. As shown in FIG. 1, when an occupant (driver) of the vehicle performs a shift switching operation via an operation unit such as a shift lever (or a shift switch), an electrical shift switching control is performed on the transmission mechanism. That is, the position of the shift lever is input to the shift device 100 via a shift sensor provided in the operation unit. Then, based on a control signal transmitted from a dedicated first MCU (Micro Controller Unit) 171 (see FIG. 7) and a second MCU 181 (see FIG. 7) provided in the shift device 100 and described later, the transmission mechanism is switched to one of the shift positions P (parking), R (reverse), N (neutral), and D (drive) corresponding to the shift operation of the occupant. Such a shift switching control is called shift-by-wire (SBW).

[0030] The shift device 100 includes an actuator unit 1 and a shift switching mechanism 2 driven by the actuator unit 1. The shift switching mechanism 2 is mechanically connected to a manual spool valve (not shown) of a hydraulic valve body in a hydraulic control circuit (not shown) in the transmission mechanism and to a parking mechanism. The shift switching mechanism 2 is configured to mechanically switch the shift state (P position, R position, N position, and D position) of the transmission by driving the shift switching mechanism 2.

[0031] The actuator unit 1 includes a motor 11, a driving force transmission mechanism 12, a first output shaft sensor 13 (see Figure 7), a second output shaft sensor 14 (see Figure 7), a first motor rotation angle sensor 15 (see Figure 7), a second motor rotation angle sensor 16 (see Figure 7), a first drive system 17 (see Figure 7), and a second drive system 18 (see Figure 7).

[0032] 1, the shift switching mechanism 2 includes a detent plate 21 (an example of a "shift switching member" in the claims) and a detent spring 22 (an example of a "positioning member" in the claims). The detent spring 22 is configured to hold the detent plate 21 at rotation angle positions corresponding to the P position, the R position, the N position, and the D position.

[0033] 2, the detent plate 21 has a plurality (four) of valleys 21a, 21b, 21c and 21d (plurality of valleys) provided to correspond to the shift positions (P position, R position, N position and D position). The valleys 21a, 21b, 21c and 21d form a cam surface Ca having a continuous undulating shape on the detent plate 21. Adjacent valleys (for example, valleys 21a and 21b, valleys 21b and 21c, etc.) are separated by a peak M having one apex T. The detent spring 22 has a base end fixed to a casing of the speed change mechanism, and a roller portion 22a attached to the free end side. The roller portion 22a of the detent spring 22 constantly presses against the cam surface Ca (any position of the valley portion 21a, the valley portion 21b, the valley portion 21c, the valley portion 21d, or the peak portion M). The detent spring 22 establishes a shift position in a state where it is fitted into any of the plurality of valley portions 21a, the valley portion 21b, the valley portion 21c, and the valley portion 21d.

[0034] Moreover, a wall portion 121a is provided in valley portion 21a located at the end portion of detent plate 21 to prevent detent spring 22 from moving beyond valley portion 21a. A wall portion 121d is provided in valley portion 21d located at the end portion of detent plate 21 in the direction of arrow A. A wall portion 121d is provided in valley portion 21a located at the end portion of detent plate 21 in the direction of arrow B.

[0035] 1, the detent plate 21 is fixed to a lower end (Z2 side) of an output shaft 12b (see FIG. 3) described later, and the detent plate 21 rotates integrally with the output shaft 12b around a rotation axis C1. As a result, the roller portion 22a of the detent spring 22 slides along the cam surface Ca in accordance with forward and reverse rotation (swing) of the detent plate 21 in the direction of the arrow A or the direction of the arrow B, so that the roller portion 22a fits into any one of the valley portions 21a, 21b, 21c, and 21d due to the biasing force of the detent spring 22. The detent spring 22 is configured such that the roller portion 22a selectively fits into any one of the valley portions 21a, 21b, 21c, and 21d of the detent plate 21, so that the detent plate 21 is held at a rotation angle position corresponding to the P position, the R position, the N position, or the D position, respectively. This results in the P position, the R position, the N position or the D position being established individually.

[0036] Next, the detailed configuration of the actuator unit 1 will be described.

[0037] 3, the motor 11 is configured with a rotor 111 rotatably supported relative to a motor housing, and a stator 112 disposed to face the periphery of the rotor 111 with a magnetic gap therebetween. The motor 11 is also configured to drive a detent plate 21.

[0038] The motor 11 is a three-phase motor of a surface permanent magnet type (SPM) in which permanent magnets are incorporated on the surface of the rotor 111. Specifically, the rotor 111 has a shaft pinion 111a and a rotor core 111b.

[0039] The shaft pinion 111a and the output shaft 12b of the rotor 111 rotate around the same rotation axis C1. In addition, the shaft pinion 111a is integrally formed with a gear portion 121 having a helical gear groove in an outer circumferential region extending from the center to the lower end (Z2 side).

[0040] Stator 112 has a stator core 112a fixed in a motor chamber of a motor housing, and excitation coils (not shown) of multiple phases (U-phase, V-phase, and W-phase) that generate magnetic force when energized.

[0041] 3 and 4, the driving force transmission mechanism 12 is configured to transmit the driving force of the motor 11 to a detent plate 21 (see FIG. 1). The driving force transmission mechanism 12 includes a reduction mechanism 12a and an output shaft 12b.

[0042] The speed reducing mechanism 12a is configured to rotate the detent plate 21 while reducing the rotation speed transmitted from the motor 11 side.

[0043] Specifically, the reduction mechanism 12a includes a gear portion 121 of the rotor 111, an intermediate gear 122 having a gear portion 122a meshing with the gear portion 121, an intermediate gear 123 arranged on the lower side (Z2 side) on the same axis as the intermediate gear 122 and engaging with the intermediate gear 122, and a final gear 124 having a gear portion 124a meshing with the gear portion 123a of the intermediate gear 123.

[0044] 5 and 6, the intermediate gear 122 has a plurality (six) of elongated holes 122b whose major diameters extend along the circumferential direction between the rotation center and the outer periphery (gear portion 122a). The plurality of elongated holes 122b are arranged at 60 degree intervals from each other in the circumferential direction. The intermediate gear 123 has an elliptical main body portion 123b on which the gear portion 123a is provided, and has a plurality (two) of cylindrical engagement protrusions 123c protruding upward from the upper surface (Z1 side) of the main body portion 123b opposite to the gear portion 123a. The engagement protrusions 123c are arranged on the periphery of both sides in the major diameter direction of the main body portion 123b. With the intermediate gear 123 positioned adjacent to the intermediate gear 122 from below toward above (Z1 side), each of the engaging protrusions 123c arranged at 180° intervals from each other is configured to be inserted (engaged) into the two long holes 122b of the corresponding intermediate gear 122.

[0045] The engaging protrusion 123c is fitted into the long hole 122b of the intermediate gear 122 with a backlash Ba of a predetermined size (length in the circumferential direction). That is, the intermediate gears 122 and 123 are configured to be allowed to rotate freely relative to each other by an amount corresponding to the backlash Ba in the circumferential direction (a predetermined angular width) generated between the engaging protrusion 123c and the long hole 122b that are fitted together. Note that FIG. 5 shows a state in which the driving force can be transmitted from the intermediate gear 122 to the intermediate gear 123, and FIG. 6 shows a state in which the driving force cannot be transmitted from the intermediate gear 122 to the intermediate gear 123.

[0046] The output shaft 12b is configured to output the driving force of the motor 11 to the detent plate 21. The output shaft 12b is connected to the output side of the speed reduction mechanism 12a. The output shaft 12b is connected to the input side of the detent plate 21. As a result, the output shaft 12b and the detent plate 21 operate integrally.

[0047] As shown in FIG. 7, the first output shaft sensor 13 is configured to detect the rotation angle of the output shaft 12b. For example, the first output shaft sensor 13 is configured with a Hall element. The rotation position (output angle) of the output shaft 12b is detected as a continuous output shaft angle. The second output shaft sensor 14 is configured to detect the rotation angle of the output shaft 12b. For example, the second output shaft sensor 14 is configured with a Hall element. The rotation position (output angle) of the output shaft 12b is detected as a continuous output shaft angle.

[0048] The first motor rotation angle sensor 15 is configured to detect the rotation angle of the rotor 111 of the motor 11. For example, the first motor rotation angle sensor 15 is configured from an MR sensor (Magneto Resistive Sensor). The second motor rotation angle sensor 16 is configured to detect the rotation angle of the rotor 111 of the motor 11. For example, the second motor rotation angle sensor 16 is configured from an MR sensor.

[0049] The first drive system 17 is configured to control the drive of the motor 11 based on the measurement values ​​of the first output shaft sensor 13 and the first motor rotation angle sensor 15. The first drive system 17 is configured to control the motor 11 independently of the second drive system 18. Specifically, the first drive system 17 has a first MCU 171 (an example of a “first control unit” in the claims), a storage unit (not shown), a first driver 172, and a first inverter 173.

[0050] The first MCU 171 and the first output shaft sensor 13 are electrically connected. The first MCU 171 and the first motor rotation angle sensor 15 are electrically connected. The first MCU 171 and the first driver 172 are electrically connected. The first driver 172 and the first inverter 173 are electrically connected.

[0051] The first MCU 171 is configured to control a voltage for driving the motor 11. The storage unit is a storage device having memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory). The first driver 172 is configured to transmit a signal for controlling the first inverter 173. The first inverter 173 has a plurality (six) of driving FETs (Field Effect Transistors) 174 that are switched ON / OFF by a signal from the first driver 172. The first inverter 173 outputs a sinusoidal three-phase AC voltage (U phase, V phase, and W phase) by switching ON / OFF of the plurality of driving FETs 174. In this manner, the first inverter 173 is configured to output a voltage for driving the motor 11. The first inverter 173 has an upper arm 173a having a plurality (three) of driving FETs 174 and a lower arm 173b having a plurality (three) of driving FETs 174.

[0052] The second drive system 18 is configured to control the driving of the motor 11 based on the measurement values ​​of the second output shaft sensor 14 and the second motor rotation angle sensor 16. The second drive system 18 is configured to control the motor 11 independently of the first drive system 17. Specifically, the second drive system 18 has a second MCU 181 (an example of a "second control unit" in the claims), a storage unit (not shown), a second driver 182, and a second inverter 183.

[0053] The second MCU 181 and the second output shaft sensor 14 are electrically connected. The second MCU 181 and the second motor rotation angle sensor 16 are electrically connected. The second MCU 181 and the second driver 182 are electrically connected. The second driver 182 and the second inverter 183 are electrically connected.

[0054] The second MCU 181 is configured to control a voltage for driving the motor 11. The storage unit is a storage device having memories such as ROM and RAM. The second driver 182 is configured to transmit a signal for controlling the second inverter 183. The second inverter 183 has a plurality of (six) driving FETs 184 whose ON / OFF is switched by a signal from the second driver 182. In the second inverter 183, a sinusoidal three-phase AC voltage (U phase, V phase, and W phase) is output by switching ON / OFF of the plurality of driving FETs 184. In this manner, the second inverter 183 is configured to output a voltage for driving the motor 11. The second inverter 183 has an upper arm 183a having a plurality of (three) driving FETs 184 and a lower arm 183b having a plurality of (three) driving FETs 184.

[0055] Next, a description will be given of the relationship between the movement of the shift position and the output value of the second output shaft sensor 14 and the output value of the second motor rotation angle sensor 16. Note that the relationship between the output value of the first output shaft sensor 13 and the output value of the first motor rotation angle sensor 15 is similar to the relationship between the output value of the second output shaft sensor 14 and the output value of the second motor rotation angle sensor 16.

[0056] 8, as the number of rotations of the motor 11 increases (0, 1, 2, ..., 7), the detent plate 21 connected to the output shaft 12b rotates so that the shift position changes in the order of P position, R position, N position, and D position. At this time, the detent spring 22 fits into the valley portion 21a, valley portion 21b, valley portion 21c, and valley portion 21d in that order. The output value of the second output shaft sensor 14 increases as the number of rotations of the motor 11 increases.

[0057] For example, as shown in Figures 9 and 10, assume that the roller portion 22a is currently fitted into the valley portion 21b (position R) (section 1). The motor 11 (see Figure 3) is driven to rotate the detent plate 21 in the direction of arrow A via the speed reduction mechanism 12a (see Figure 3). A predetermined amount of backlash Ba (see Figure 6) is provided between the intermediate gears 122 and 123. Therefore, when the roller portion 22a is completely fitted into the valley bottom V of the valley portion 21b, the intermediate gear 122 rotates with the rotation of the rotor 111, but the intermediate gear 123 does not rotate because the engaging protrusion 123c is engaged inside the long hole 122b by utilizing the backlash Ba so as not to transmit driving force. As a result, in section 1, the rotation angle (rad) of the motor 11 detected by the second motor rotation angle sensor 16 (see Figure 8) increases linearly, while the rotation angle (output shaft angle (rad)) of the output shaft 12b detected by the second output shaft sensor 14 (see Figure 8) remains constant.

[0058] Thereafter, in section 2, one end of the long hole 122b of the intermediate gear 122 is engaged with the engaging protrusion 123c of the intermediate gear 123 so as to be capable of transmitting the driving force, and thus the driving force of the motor 11 is transmitted to the output shaft 12b (see FIG. 1) via the gear portion 121, the intermediate gear 122, the intermediate gear 123, and the final gear 124 (see FIG. 3). Then, as the detent plate 21 rotates in the direction of the arrow A, the roller portion 22a moves so as to climb the slope on the side of the valley portion 21c (N position) of the valley portion 21b (R position) toward the peak portion M. Note that, in section 2, the rotation angle (rad) of the motor 11 detected by the second motor rotation angle sensor 16 (see FIG. 8) increases linearly. Also, the rotation angle (rad) of the output shaft 12b detected by the second output shaft sensor 14 (see FIG. 8) increases at a constant rate.

[0059] Then, in section 3, after the roller portion 22a climbs over the peak portion M at the boundary between the valley portion 21b (position R) and the valley portion 21c (position N), the detent plate 21 rotates prior to the motor 11 (intermediate gear 122). That is, the detent plate 21 is always biased toward the valley portion 21b by the roller portion 22a, and this biasing force causes the detent plate 21 to rotate prior to the motor 11 within the range of the size of the backlash Ba of the long hole 122b. Then, the roller portion 22a drops toward the valley bottom V of the valley portion 21b (see section 3 in FIG. 8). At this time, the rotation angle of the motor 11 increases, while the rotation angle (rad) of the output shaft 12b increases rapidly as the roller portion 22a drops (sucks) into the valley bottom V.

[0060] The operation of moving the shift position from the P position to the R position and the operation of moving from the N position to the D position are the same as the operation of moving from the R position to the N position described above.

[0061] 8 and 10, the rotation direction of the motor 11 is reversed, so that the shift position moves through the N position (section 4), section 5, and section 6 to the R position.

[0062] The operation in the N position (section 4) is the same as that in the above-mentioned section 1. That is, the rotation angle (rad) of the motor 11 detected by the second motor rotation angle sensor 16 decreases linearly, while the rotation angle (rad) of the output shaft 12b detected by the second output shaft sensor 14 is constant.

[0063] Moreover, the operation in section 5 is similar to the operation in the above-mentioned section 2. That is, in section 5, the rotation angle of the motor 11 decreases linearly, and the rotation angle (rad) of the output shaft 12b decreases at a constant rate.

[0064] The operation in section 6 is similar to that in section 3. That is, while the rotation angle of the motor 11 decreases, the rotation angle (rad) of the output shaft 12b decreases rapidly as the roller portion 22a falls (sucks) into the valley bottom V.

[0065] In the shift device 100, for example, at the time of shipment from the factory, the rotation angle of the motor 11 (rotor 111) corresponding to the valley bottom V is acquired (learned) for each shift device 100. That is, the rotation angle of the motor 11 (rotor 111) corresponding to the valley bottom V (center of backlash Ba) at each of a plurality of shift positions (P position, R position, N position, and D position) is acquired (learned). In detail, the backlash width W included in the reduction mechanism unit 12a is detected at the valley portion 21a, the valley portion 21b, the valley portion 21c, and the valley portion 21d corresponding to the plurality of shift positions (P position, R position, N position, and D position). Then, the center of the detected width W of the backlash Ba is learned as the valley bottom V (shift position). The acquisition of the rotation angle of the motor 11 corresponding to the valley bottom V is performed by the first MCU 171 and the second MCU 181.

[0066] As a result, in the shift device 100, the first MCU 171 and the second MCU 181 switch the shift position based on the rotation angle of the motor 11 corresponding to the valley bottom V acquired by each of the first MCU 171 and the second MCU 181. That is, in the shift device 100, control is performed to move the detent spring 22 to the position of the valley bottom V corresponding to each of the P position, R position, N position, and D position selected by the shift operation of the occupant.

[0067] (Drive control by both systems) Here, the shift device 100 of this embodiment is configured to switch the shift position by driving the motor 11 with voltages output from both the first drive system 17 and the second drive system 18. That is, each of the first MCU 171 and the second MCU 181 is configured to independently (asynchronously) control the movement of the detent spring 22 to a valley V position corresponding to each of the P position, R position, N position, and D position selected by the shift operation of the occupant.

[0068] Specifically, the shift device 100 is configured such that, when changing the shift position, the motor 11 is driven by the first drive system 17 based on the measurement values ​​of the first motor rotation angle sensor 15 and the first output shaft sensor 13, and the motor 11 is driven by the second drive system 18 based on the measurement values ​​of the second motor rotation angle sensor 16 and the second output shaft sensor 14.

[0069] Here, when the motor 11 is driven by both the first drive system 17 and the second drive system 18, the ON / OFF switching of each of the multiple (six) drive FETs 174 of the first drive system 17 changes the conduction pattern of the drive current output to the motor 11. Also, when the motor 11 is driven by both the first drive system 17 and the second drive system 18, the ON / OFF switching of each of the multiple (six) drive FETs 184 of the second drive system 18 changes the conduction pattern of the drive current output to the motor 11.

[0070] 11 shows an example of a conduction pattern of the drive current output to the motor 11. In the first drive system 17, the U-phase drive FET 174 of the upper arm 173a is ON, the V-phase drive FET 174 of the upper arm 173a is OFF, and the W-phase drive FET 174 of the upper arm 173a is OFF. In the first drive system 17, the U-phase drive FET 174 of the lower arm 173b is OFF, the V-phase drive FET 174 of the lower arm 173b is ON, and the W-phase drive FET 174 of the lower arm 173b is ON.

[0071] In the second drive system 18, the U-phase drive FET 184 of the upper arm 183a is ON, the V-phase drive FET 184 of the upper arm 183a is OFF, and the W-phase drive FET 184 of the upper arm 183a is OFF. In the second drive system 18, the U-phase drive FET 184 of the lower arm 183b is OFF, the V-phase drive FET 184 of the lower arm 183b is ON, and the W-phase drive FET 184 of the lower arm 183b is ON.

[0072] As a result, in the first drive system 17, a drive current flows from the U phase of the upper arm 173a through the excitation coil of the motor 11 to each of the V phase and W phase of the lower arm 173b, and in the second drive system 18, a drive current flows from the U phase of the upper arm 183a through the excitation coil of the motor 11 to each of the V phase and W phase of the lower arm 183b, thereby driving the motor 11.

[0073] Here, when the motor 11 is driven by both the first drive system 17 and the second drive system 18 during shift switching, the first drive system 17 and the second drive system 18 each drive the motor 11 independently, which raises concerns about drive interference between the systems. The drive interference will be described with reference to Fig. 12, which shows an example of a state in which the shift position is switched from the P position to the R position.

[0074] 12, in the shift device 100, a valley bottom learning position P1 (an example of a "pre-acquired shift position" in the claims) of the valley bottom V of valley portions 21a, 21b, 21c, and 21d corresponding to the P position, R position, N position, and D position, respectively, is learned (acquired) in advance by the first MCU 171 of the first drive system 17. Also, the first MCU 171 has preset a first reach range R1 (an example of a "position reach determination range" in the claims) within which it is determined that the detent spring 22 has reached the valley bottom learning position P1. The first reachable range R1 is set based on design values ​​such as the valley bottom learning position P1 of each valley bottom V of valley portion 21a, valley portion 21b, valley portion 21c and valley portion 21d which have been learned in advance, the error variation between the actual valley bottom position Pr of the actual valley bottom V and the valley bottom learning position P1 learned in the first drive system 17, and the allowable error for the motor 11 to stop.

[0075] Similarly, in the shift device 100, a valley bottom learning position P2 (an example of a "pre-acquired shift position" in the claims) of the valley bottom V of valley portion 21a, valley portion 21b, valley portion 21c, and valley portion 21d corresponding to the P position, R position, N position, and D position, respectively, is learned (acquired) in advance by the second MCU 181 of the second drive system 18 separately from the first drive system 17. Also, the second MCU 181 has previously set a second reach range R2 (an example of a "position reach determination range" in the claims) for determining that the detent spring 22 has reached the valley bottom learning position P2 of each of the learned valley bottom V of valley portion 21a, valley portion 21b, valley portion 21c, and valley portion 21d. The second reachable range R2 is set based on design values ​​such as the valley bottom learning positions P2 of each of the valley bottoms V of valley portions 21a, 21b, 21c and 21d which have been learned in advance, the error variation between the actual valley bottom position Pr of the actual valley bottom V and the valley bottom learning position P2 learned in the second drive system 18, and the allowable error for the motor 11 to stop.

[0076] There is variation in the valley bottom learning position P1 learned in the first drive system 17 and the valley bottom learning position P2 learned in the second drive system 18. For this reason, for example, as shown in Fig. 12, there are cases where the valley bottom learning position P1 at the R position in the first drive system 17 is closer to the P position than the actual valley bottom position Pr, and the valley bottom learning position P2 at the R position in the second drive system 18 is closer to the N position than the actual valley bottom position Pr.

[0077] In this case, because the detent spring 22 enters the first reach range R1, the first MCU 171 determines that the shift position has been switched to the R position before the second MCU 181 does. On the other hand, because the detent spring 22 does not enter the second reach range R2, the second MCU 181 does not determine that the shift position has been switched to the R position. Here, if the first MCU 171 performs control to brake the motor 11 based on the fact that the detent spring 22 has entered the first reach range R1, the second MCU 181 performs control to drive the motor 11 in order to bring the detent spring 22 into the second reach range R2, and therefore the drive of the second drive system 18 is hindered due to the first drive system 17. This is drive interference between the systems.

[0078] Therefore, the shift device 100 is configured so that when the detent spring 22 reaches each of the valleys 21a, 21b, 21c, and 21d, the preceding system of the first drive system 17 and the second drive system 18 that has determined that the detent spring 22 has reached each of the valleys 21a, 21b, 21c, and 21d first does not perform braking processing for the motor 11. In the example shown in Fig. 12, the first MCU 171 of the preceding first drive system 17 that has determined that the detent spring 22 has reached the valley 21b first is configured to perform control so that the motor 11 can be freely driven without braking, based on the fact that the detent spring 22 has entered the first reach range R1.

[0079] That is, the shift device 100 is configured not to perform braking processing of the motor 11 when the motor reaches each of the valleys 21a, 21b, 21c, and 21d by turning off the first inverter 173 of the first drive system 17 as one of the preceding drive systems, or by turning off the second inverter 183 of the second drive system 18 as one of the preceding drive systems. In the example shown in Fig. 12 and Fig. 13, the first MCU 171 of the preceding first drive system 17 that has previously determined that the detent spring 22 has reached the valley 21b is configured to perform control so that the motor 11 can be freely driven without braking by turning off all of the first inverters 173 based on the fact that the detent spring 22 has entered the first reach range R1.

[0080] Specifically, when the preceding system is the first drive system 17, the first MCU 171 is configured to control the motor 11 not to brake when it reaches each of the valleys 21a, 21b, 21c, and 21d, based on the fact that the difference between the valley-bottom learning position P1 and the current position of the detent spring 22 is within the first reach range R1 and the rotational speed of the motor 11 is within the speed reach determination range. When the preceding system is the second drive system 18, the second MCU 181 is configured to control the motor 11 not to brake when it reaches each of the valleys 21a, 21b, 21c, and 21d, based on the fact that the difference between the valley-bottom learning position P2 and the current position of the detent spring 22 is within the second reach range R2 and the rotational speed of the motor 11 is within the speed reach determination range.

[0081] Here, the condition that the difference from the current position of the detent spring 22 is within the first reach range R1 and the condition that the difference from the current position of the detent spring 22 is within the second reach range R2 are conditions for checking the position of the detent spring 22. Also, the rotational speed of the motor 11 being within the speed reach determination range is an upper limit for checking whether the rotational speed is sufficiently decelerated when reaching the bottom V of each of the valleys 21a, 21b, 21c, and 21d.

[0082] Specifically, the preceding drive system is configured not to brake for a predetermined time when it reaches the bottom V of each of the valleys 21a, 21b, 21c, and 21d. The predetermined time means a time during which the detent spring 22, which has entered the first reach range R1, can enter the second reach range R2 when the preceding drive system is the first drive system 17. The predetermined time means a time during which the detent spring 22, which has entered the second reach range R2, can enter the first reach range R1 when the preceding drive system is the second drive system 18. The predetermined time is calculated by the first MCU 171 based on the rotation speed of the motor 11 immediately before it reaches the first reach range R1, or calculated by the second MCU 181 based on the rotation speed of the motor 11 immediately before it reaches the second reach range R2.

[0083] Also, the preceding drive system is configured to brake the motor 11 based on the lapse of a predetermined time. That is, when the preceding drive system is the first drive system 17, the first MCU 171 is configured to perform control to turn on the drive FET 174 (switching element) on the lower arm 173b side of the first inverter 173 of the first drive system 17 and to turn off the drive FET 174 (switching element) on the upper arm 173a side of the first inverter 173 of the first drive system 17 based on the lapse of a predetermined time. When the preceding drive system is the second drive system 18, the second MCU 181 is configured to perform control to turn on the drive FET 184 (switching element) on the lower arm 183b side of the second inverter 183 of the second drive system 18 and to turn off the drive FET 184 (switching element) on the upper arm 183a side of the second inverter 183 of the second drive system 18 based on the lapse of a predetermined time. As a result, the drive of the motor 11 is braked (short brake).

[0084] Furthermore, after a predetermined time has elapsed, the position of the detent spring 22 is within the first reach range R1 and within the second reach range R2, so that the motor 11 is braked by both the first drive system 17 and the second drive system 18, as shown in Figure 14.

[0085] (Shift switching process) The shift switching process when the first drive system 17 reaches any one of the valleys 21a, 21b, 21c, and 21d first will be described below with reference to Fig. 15. In the shift switching process, the driving of the motor 11 by the first drive system 17 and the driving of the motor 11 by the second drive system 18 are performed in parallel.

[0086] In step S1, the first MCU 171 determines whether the detent spring 22 has entered the first reach range R1. If the detent spring 22 has entered the first reach range R1, the process proceeds to step S2, and if the detent spring 22 has not entered the first reach range R1, the process returns to step S1. In step S2, the first MCU 171 determines whether the rotation speed of the motor 11 is within the speed reach determination range. If the rotation speed of the motor 11 is within the speed reach determination range, the process proceeds to step S3, and if the rotation speed of the motor 11 is not within the speed reach determination range, the process returns to step S1.

[0087] In step S3, the first MCU 171 executes the free mode as the drive control mode of the motor 11. That is, the first MCU 171 performs control such that the second drive system 18 can freely drive the motor 11 without braking the motor 11 by turning off all the drive FETs 184 of the first inverter 173. In step S4, the first MCU 171 determines whether or not a predetermined time has elapsed. If the predetermined time has elapsed, the process proceeds to step S5, and if the predetermined time has not elapsed, the process returns to step S3. In step S5, the first MCU 171 brakes the motor 11 and then repeats step S1.

[0088] In addition, the shift switching process when the second drive system 18 reaches any one of the valleys 21a, 21b, 21c, and 21d first will be described below with reference to Fig. 16. In the shift switching process, the driving of the motor 11 by the first drive system 17 and the driving of the motor 11 by the second drive system 18 are performed in parallel.

[0089] In step S21, the second MCU 181 determines whether the detent spring 22 has entered the second reach range R2. If the detent spring 22 has entered the second reach range R2, the process proceeds to step S22, and if the detent spring 22 has not entered the second reach range R2, the process returns to step S21. In step S22, the second MCU 181 determines whether the rotational speed of the motor 11 is within the speed reach determination range. If the rotational speed of the motor 11 is within the speed reach determination range, the process proceeds to step S23, and if the rotational speed of the motor 11 is not within the speed reach determination range, the process returns to step S21.

[0090] In step S23, the second MCU 181 executes the free mode as the drive control mode of the motor 11. That is, the second MCU 181 performs control such that the first drive system 17 can freely drive the motor 11 without braking the motor 11 by turning off all the drive FETs 184 of the second inverter 183. In step S24, the second MCU 181 determines whether or not a predetermined time has elapsed. If the predetermined time has elapsed, the process proceeds to step S25, and if the predetermined time has not elapsed, the process returns to step S23. In step S25, the second MCU 181 brakes the motor 11 and then repeats step S21.

[0091] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0092] In this embodiment, as described above, the shift position is changed by driving the motor 11 with the voltages output from both the first drive system 17 and the second drive system 18. As a result, if a failure is detected in either the first drive system 17 or the second drive system 18 during shift switching, a procedure (fail-safe) can be performed to stop the drive of the motor 11 by the failed drive system while the drive of the motor 11 by the normal drive system continues, so that the drive of the motor 11 can be continued. As a result, since the drive control of the motor 11 is not performed intermittently when a failure is detected in either the first drive system 17 or the second drive system 18 during shift switching, the drive control of the motor 11 can be performed smoothly even if an abnormality is detected during shift switching. Furthermore, by driving the motor 11 using both the first drive system 17 and the second drive system 18, the power required to output the maximum torque of the motor 11 can be distributed to each of the first drive system 17 and the second drive system 18, so that the size of each of the first drive system 17 and the second drive system 18 can be prevented from increasing compared to the case where the maximum torque of the motor 11 is output using only one of the first drive system 17 and the second drive system 18.

[0093] Furthermore, in this embodiment, as described above, when the detent spring 22 reaches each of the valleys 21a, 21b, 21c, and 21d, the preceding system of the first drive system 17 and the second drive system 18 that has determined that the detent spring 22 has reached each of the valleys 21a, 21b, 21c, and 21d first is configured not to perform braking processing for the motor 11. This makes it possible to prevent the preceding drive system from braking the motor 11 before the other drive system that has been delayed in determining that the detent spring 22 has reached each of the valleys 21a, 21b, 21c, and 21d has determined that the detent spring 22 has reached each of the valleys 21a, 21b, 21c, and 21d, so that driving of the motor 11 by the other drive system is not hindered.

[0094] In addition, in this embodiment, as described above, the first inverter 173 of the first drive system 17, which is the preceding drive system that is determined to have first reached each of valleys 21a, 21b, 21c and 21d, is turned off, or the second inverter 183 of the second drive system 18, which is the preceding drive system that is determined to have first reached each of valleys 21a, 21b, 21c and 21d, is turned off, so that braking processing of the motor 11 is not performed when the detent spring 22 reaches each of valleys 21a, 21b, 21c and 21d. As a result, power is not supplied to the motor 11 from the preceding drive system that has determined that the detent spring 22 has reached each of the valleys 21a, 21b, 21c, and 21d first, so that the motor 11 can be driven only by the other drive system that has been delayed in determining that the detent spring 22 has reached each of the valleys 21a, 21b, 21c, and 21d. As a result, the motor 11 can be driven as intended by the other delayed drive system.

[0095] In the present embodiment, as described above, the preceding drive system that has been determined to have the detent spring 22 reach each of the valleys 21a, 21b, 21c, and 21d first is configured not to brake for a predetermined time when the detent spring 22 reaches each of the valleys 21a, 21b, 21c, and 21d. This ensures a predetermined time during which the motor 11 can be driven as intended by the other drive system that has been delayed in determining that the detent spring 22 has reached each of the valleys 21a, 21b, 21c, and 21d, and therefore the delayed drive system can also reliably reach each of the valleys 21a, 21b, 21c, and 21d.

[0096] In this embodiment, as described above, the preceding drive system is configured to brake the motor 11 based on the lapse of a predetermined time. This allows the detent spring 22 to be stopped near the valley bottom learning position P1 (valley bottom learning position P2) of each of the valleys 21a, 21b, 21c, and 21d learned in advance in one drive system while ensuring the drive time of the motor 11 only by the other drive system in which it is delayed in determining that the detent spring 22 has reached each of the valleys 21a, 21b, 21c, and 21d, so that drive interference between the first drive system 17 and the second drive system 18 can be suppressed and shift switching can be performed accurately.

[0097] In the present embodiment, as described above, the preceding system that has determined that the detent spring 22 has reached each of the valleys 21a, 21b, 21c, and 21d first is configured not to perform the braking process of the motor 11 when the detent spring 22 reaches each of the valleys 21a, 21b, 21c, and 21d, based on the fact that the difference between the previously acquired shift position and the current position of the detent spring 22 is within the first reach range R1 (second reach range R2) and the rotation speed of the motor 11 is within the speed reach determination range. This allows the detent spring 22 to enter the first reach range R1 (second reach range R2) in a state in which the motor 11 is sufficiently decelerated so that the detent spring 22 does not pass over the shift position, so that it is possible to prevent the detent spring 22 from passing over the shift position due to the lack of the braking process of the motor 11.

[0098] [Variations] The above-described embodiments disclosed herein should be considered as illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the description of the above-described embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0099] For example, in the above embodiment, an example was shown in which the leading one of the first drive system 17 and the second drive system 18 is configured not to brake the motor 11 when it reaches each of the valleys 21a, 21b, 21c, and 21d, but the present invention is not limited to this. In the present invention, the leading one of the first drive system and the second drive system may brake the motor when it reaches each of the multiple valleys.

[0100] In the above embodiment, the width W of the backlash Ba is the width W of the backlash Ba of the reduction mechanism 12a, but the present invention is not limited to this. In the present invention, the backlash width may include a backlash width other than that of the reduction mechanism in the driving force transmission mechanism.

[0101] In the above embodiment, the shift device 100 of the present invention is applied to a shift device for an automobile, but the present invention is not limited to this. In the present invention, the shift device may be applied to a shift device for a vehicle other than an automobile, such as a train.

[0102] In the above embodiment, an example has been described in which the first inverter 173 outputs a sinusoidal three-phase AC voltage (U phase, V phase, and W phase) by switching ON / OFF of the multiple drive FETs 174, but the present invention is not limited to this. In the present invention, the first inverter may output a pulse wave three-phase AC voltage (U phase, V phase, and W phase) by switching ON / OFF of the multiple drive FETs.

[0103] In the above embodiment, an example has been described in which the second inverter 183 outputs a sine wave three-phase AC voltage (U phase, V phase, and W phase) by switching ON / OFF of the multiple drive FETs 184, but the present invention is not limited to this. In the present invention, the second inverter may output a pulse wave three-phase AC voltage (U phase, V phase, and W phase) by switching ON / OFF of the multiple drive FETs.

[0104] In the above embodiment, for convenience of explanation, the control processing of the first MCU 171 (first control unit) and the second MCU 181 (second control unit) is explained using a flow-driven flowchart in which the processing is performed in order according to the processing flow, but the present invention is not limited to this. In the present invention, the control processing of the first control unit and the second control unit may be performed by event-driven processing in which processing is performed on an event-by-event basis. In this case, the control processing may be performed completely event-driven, or may be performed in a combination of event-driven and flow-driven. [Explanation of symbols]

[0105] 11 Motor 17 First drive system 18 Second drive system 21 Detent plate (shift switching member) 21a, 21b, 21c, 21d Tanibe 22 Detent spring (positioning member) 100 Shifting device 111 Rotor 112 Stator 173 First inverter 183 Second inverter

Claims

1. a shift switching member including a plurality of valleys corresponding to a shift position; a motor including a rotor and a stator for driving the shift switching member; a first drive system including a first inverter that outputs a voltage for driving the motor; a second drive system provided separately from the first drive system and including a second inverter that outputs a voltage for driving the motor; a positioning member for establishing the shift position in a state where the positioning member is fitted into any one of the plurality of valley portions of the shift switching member, The motor is driven by voltages output from both the first drive system and the second drive system to switch the shift position, a shift device configured such that when the positioning member reaches the bottom of each of the plurality of valley portions, one of the first drive system and the second drive system does not brake the motor, and the other drive system drives the motor to move the positioning member toward the valley bottom, and then, after a predetermined time has elapsed, the one drive system brakes the motor to stop the positioning member.

2. A first reach range within which it is determined that the first drive system has reached the bottom of each of the plurality of valley portions based on the shift position previously acquired, and a second reach range within which it is determined that the second drive system has reached the bottom of each of the plurality of valley portions, are set; when the positioning member reaches the bottom of each of the plurality of valleys, based on a determination that the positioning member has reached one of the first reach range and the second reach range and has not reached the other, a drive system corresponding to one of the first reach range and the second reach range does not brake the motor, and a drive system corresponding to the other of the first reach range and the second reach range drives the motor to move the positioning member toward the bottom of the valley, 2. The shift device of claim 1, wherein the drive system corresponding to the one of the first reach range and the second reach range is configured to brake the motor based on the lapse of the predetermined time after it is determined that the positioning member has reached one of the first reach range and the second reach range but has not reached the other of the first reach range and the second reach range.

3. 3. The shift device of claim 2, wherein the shift device is configured not to perform braking of the motor when the positioning member reaches each of the plurality of valleys by turning off the first inverter of the first drive system as the preceding drive system determined to have reached each of the plurality of valleys first, or by turning off the second inverter of the second drive system as the preceding drive system determined to have reached each of the plurality of valleys first.

4. 4. The shift device according to claim 2, wherein the preceding drive system, which has been determined to have reached each of the plurality of valleys first, is configured not to brake for a predetermined time when the positioning member reaches each of the plurality of valleys.

5. The shift device according to any one of claims 2 to 4, wherein the preceding system that has determined that the positioning member has reached each of the plurality of valleys first is configured not to brake the motor when the positioning member reaches each of the plurality of valleys, based on the fact that a difference between the shift position acquired in advance and a current position of the positioning member is within a position reach determination range and that a rotational speed of the motor is within a speed reach determination range.

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