Shift device

Abstract

This shift device is provided with: a shift switching member including a plurality of valley sections; a positioning member for achieving a shift position in a state of being fitted into any from among the plurality of valley sections of the shift switching member; a motor which includes a rotor and a stator, and which drives the shift switching member; a rotor rotation angle sensor; and an output shaft rotation angle sensor which detects the rotation angle of the shift switching member. When the positioning member is moved so as to pass through the plurality of valley sections, the rotation angles of the motor corresponding to valley bottoms of the plurality of valley sections are acquired, on the basis of values output by the rotor rotation angle sensor and the output shaft rotation angle sensor as well as design values in which values output by the output shaft rotation angle sensor and shift positions are associated with each other, by detecting a valley bottom of the valley section at the end of the plurality of valley sections to reverse the movement of the positioning member.

Description

[Technical Field]

[0001] The present invention relates to a shift device mounted on a vehicle. [Background technology]

[0002] BACKGROUND ART Shift devices mounted on vehicles are known in the art. Such a shift device is disclosed, for example, in Japanese Patent Application Laid-Open No. 2005-69406.

[0003] The aforementioned Japanese Patent Application Laid-Open Publication No. 2005-69406 discloses a shift range switching device (shift switching device) equipped with an actuator including a motor that operates based on a control signal corresponding to a shift operation by a vehicle occupant, and a shift switching mechanism that switches shift positions by being driven by the actuator. The shift switching mechanism includes a detent plate (shift switching member) and a detent spring (positioning member) with a roller (pin) at its tip. The detent plate is a plate that includes multiple valleys corresponding to the shift positions. The detent spring establishes a shift position when the roller at its tip is fitted into one of the multiple valleys of the detent plate. Furthermore, the detent plate is fixed to the output shaft of the actuator, and therefore rotates integrally with the output shaft of the actuator. Furthermore, the detent plate (shift switching member) is mechanically connected to a transmission mechanism that performs the shift switching operation.

[0004] In the above-mentioned Japanese Patent Application Laid-Open Publication No. 2005-69406, an actuator rotates based on a control signal from a control unit in response to an occupant's operation of an operating unit, and the rotation of the actuator is transmitted to an output shaft. Then, as the detent plate rotates together with the output shaft, a roller at the tip of a detent spring located in one valley of the detent plate moves to another valley, thereby changing the shift position. Furthermore, one of the valleys at the end of the detent plate has a wall portion with an inclination angle that prevents the roller at the tip of the detent spring from climbing over it.

[0005] Furthermore, in the shift range switching device described in JP 2005-69406 A, in order to improve the positioning accuracy of the roller at the tip of the detent spring relative to the detent plate, the position of the bottom of the valley portion into which the roller at the tip of the detent spring fits is acquired (learned) in advance. As a result of this learning, drive control of the detent plate is performed to prevent the roller at the tip of the detent spring from strongly hitting a wall portion when the vehicle is actually driven.

[0006] The learning performed by the shift range switching device (shift switching device) described in the above-mentioned JP 2005-69406 A includes a step of deliberately bringing the roller at the tip of the detent spring (positioning member) into contact (collides) with a wall portion, and then pressing the roller at the tip of the detent spring against the wall portion, thereby deflecting the main body of the detent spring with the roller at its tip, thereby obtaining the position of the wall portion. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-69406 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the shift range switching device described in the above-mentioned JP 2005-69406 A, during learning, the roller (pin) at the tip of the detent spring (positioning member) must come into contact (collide) with a wall portion, and the roller must be pressed against the wall portion to deflect the main body of the detent spring with the roller at its tip.This places a load on the transmission mechanism that is mechanically connected to the detent plate (shift switching member), which poses a problem of reduced durability of the transmission mechanism.

[0009] 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 can prevent a decrease in the durability of a transmission mechanism part that is mechanically connected to a shift switching member, and that can prevent a decrease in the positioning accuracy of the shift position. [Means for solving the problem]

[0010] In order to achieve the above object, a shift device in a first aspect of the present invention is mounted on a vehicle and includes: a shift switching member including a plurality of valleys provided to correspond to shift positions; a positioning member for establishing a shift position when the positioning member is fitted into one of the plurality of valleys of the shift switching member; a motor including a rotor and a stator for driving the shift switching member; a rotor rotation angle sensor for detecting a rotation angle of the rotor; an output shaft rotation angle sensor for detecting a rotation angle of the shift switching member; and a storage unit in which a design value obtained in advance that associates an output value of the output shaft rotation angle sensor with a shift position is stored, wherein when the positioning member is moved to pass through the plurality of valleys, , out A current shift position is acquired at least when the motor starts to be driven based on an output value of the force shaft rotation angle sensor and a design value stored in a storage unit, and Based on the output values ​​of the rotor rotation angle sensor and the output shaft rotation angle sensor and the design values ​​stored in the storage unit, Detect the bottom of the end valley among multiple valleys It is configured to , At the bottom of the detected edge valley Reverse the movement of the positioning member At the same time, based on the output values ​​of the rotor rotation angle sensor and the output shaft rotation angle sensor and the design value, when the same bottom of the valley as the bottom of the valley detected at the start of driving of the motor is detected again in the same rotation direction as when the motor started to be driven, driving of the motor is stopped. By doing so, the rotation angles of the motor corresponding to the bottoms of the plurality of valleys are obtained.

[0011] In the shift device according to a first aspect of the present invention, as described above, when the positioning member is moved to pass through the plurality of valleys, the bottom of an end valley among the plurality of valleys is detected based on output values ​​of the rotor rotation angle sensor and the output shaft rotation angle sensor and a design value correlating the output value of the output shaft rotation angle sensor with the shift position, and the movement of the positioning member is reversed to acquire (learn) the rotation angle of the motor corresponding to the bottom of the plurality of valleys. This allows the bottom of an end valley (a valley having a wall portion) among the plurality of valleys to be detected and the movement of the positioning member to be reversed based on the output values ​​of the rotor rotation angle sensor and the output shaft rotation angle sensor and a design value correlating the output value of the output shaft rotation angle sensor with the shift position. Therefore, when the bottom of the end valley (a valley having a wall portion) is detected, the movement direction of the positioning member can be changed so that the positioning member is further separated from the wall portion. As a result, learning can be performed without the positioning member colliding with the wall portion of the end valley. Therefore, it is possible to prevent a decrease in the durability of the transmission mechanism that is mechanically connected to the shift switching member, and it is also possible to prevent a decrease in the positioning accuracy of the shift position.

[0012] The shift device according to the first aspect preferably further comprises a speed reduction mechanism having a predetermined amount of backlash that prevents a driving force from being transmitted from the motor to the shift switching member, and rotating the shift switching member while reducing the rotational speed transmitted from the motor side; and a rotor rotation angle sensor. While the output value is fluctuating, the effect of backlash Output value of output shaft rotation angle sensor The state where the value of the valley is approximately constant is detected as the bottom of the valley. Bottom of the valley at the end Whether or not the rotation angle is within the specified range is determined based on the design value and the output value of the output shaft rotation angle sensor. configured and detected Tani The bottom of the valley When it is determined that the bottom of the valley at the end By reversing the movement of the positioning member, the rotation angles of the motor corresponding to the bottoms of the plurality of valleys are obtained.

[0013] With this configuration, the positioning member can be held at the bottom of the valley portion of the shift switching member without moving the shift switching member in response to the drive of the motor by an amount corresponding to a predetermined amount of backlash (play) intentionally provided in the speed reduction mechanism. Therefore, it is possible to learn the position of the bottom of the valley portion into which the positioning member fits without applying an excessive load (external force) to the motor or the positioning member.

[0014] In the shift device according to the first aspect, the positioning member is preferably configured to reciprocate once between both end portions of the plurality of valley portions to obtain the rotational angle of the motor corresponding to the bottoms of the plurality of valley portions.

[0015] With this configuration, the positioning member can be moved back and forth between both ends of the multiple valley sections to obtain (learn) the rotational angles of the motor corresponding to the bottoms of the multiple valley sections, thereby shortening the tact time required to obtain the rotational angles of the motor corresponding to the bottoms of the multiple valley sections.

[0016] In this case, preferably, when the positioning member is moved to pass through the plurality of valleys, if, after the motor starts to drive, the output values ​​of the rotor rotation angle sensor and the output shaft rotation angle sensor and the design value are used, and the same valley bottom as the valley bottom detected when the motor started to drive is detected again in the same rotation direction as when the motor started to drive, it is determined that the motor rotation angle corresponding to the valley bottoms of the plurality of valleys has been obtained, and the motor drive is stopped.

[0017] With this configuration, if, after the motor starts to drive, the bottom of the same valley section is detected again in the same rotation direction as when the motor started to drive and in the same direction as when the motor started to drive, the motor can be stopped, thereby making it possible to reliably detect that the positioning member has made one round trip between both ends of the multiple valley sections.

[0018] In the shift device according to the first aspect, the plurality of valleys preferably include a parking position, a reverse position, a neutral position, and a drive position as shift positions, in this order from one end to the other end, and are configured to obtain motor rotation angles corresponding to the parking position, the reverse position, the neutral position, and the drive position while the positioning member is moved sequentially through the parking position, the reverse position, the neutral position, and the drive position.

[0019] With this configuration, the movement of the positioning member can be reversed at the parking position and drive position located at the ends, thereby obtaining (learning) the motor rotation angles corresponding to the parking position, reverse position, neutral position, and drive position.

[0020] In this case, it is preferable that the shift switching member is configured to detect positions other than the four shift positions of the parking position, reverse position, neutral position, and drive position as being in an indeterminate shift position where the design value is not associated with the output value of the output shaft rotation angle sensor.

[0021] With this configuration, it is possible to detect not only whether the positioning member is in the parking position, reverse position, neutral position, or drive position, but also whether the positioning member is in a position that does not correspond to any of the four shift positions of the parking position, reverse position, neutral position, or drive position (an indeterminate shift position).As a result, the position of the positioning member can be detected more precisely, and the rotation angle of the motor corresponding to the shift position can be acquired (learned) with higher accuracy.

[0022] a rotor rotation angle sensor that detects a rotation angle of the shift switching member; and a storage unit that stores a design value that correlates an output value of the output shaft rotation angle sensor with a shift position. The shift device according to a second aspect of the present invention is a shift device mounted on a vehicle, the shift device including: a shift switching member including a plurality of valleys that are provided to correspond to shift positions; a positioning member that establishes the shift position when the positioning member is fitted into one of the plurality of valleys of the shift switching member; a motor that drives the shift switching member and includes a rotor and a stator; a rotor rotation angle sensor that detects a rotation angle of the rotor; an output shaft rotation angle sensor that detects a rotation angle of the shift switching member; and a storage unit that stores a design value that correlates an output value of the output shaft rotation angle sensor with a shift position. When the positioning member is moved to pass through the plurality of valleys, the shift device acquires a current shift position at least when starting to drive the motor based on the output value of the output shaft rotation angle sensor and the design value stored in the storage unit, and moves the positioning member back and forth between the inside of the valleys at both ends of the plurality of valleys based on the output values ​​of the rotor rotation angle sensor and the output shaft rotation angle sensor and the design value stored in the storage unit. Ruko By this, the rotation angles of the motor corresponding to the bottoms of the plurality of valleys are obtained.

[0023] In a shift device according to a second aspect of the present invention, as described above, when the positioning member is moved through the plurality of valleys, the positioning member is reciprocated between both ends of the plurality of valleys to acquire the rotational angles of the motor corresponding to the bottoms of the plurality of valleys based on output values ​​of the rotor rotation angle sensor and the output shaft rotation angle sensor and a design value correlating the output value of the output shaft rotation angle sensor with the shift position. This allows the positioning member to be reciprocated between both ends of the plurality of valleys to acquire the rotational angles of the motor corresponding to the bottoms of the plurality of valleys based on the output values ​​of the rotor rotation angle sensor and the output shaft rotation angle sensor and a design value correlating the output value of the output shaft rotation angle sensor with the shift position during learning. As a result, learning can be performed without causing the positioning member to collide with a wall provided at the end. This prevents a decrease in durability of the transmission mechanism mechanically connected to the shift switching member and a decrease in the positioning accuracy of the shift position. Furthermore, since it is not necessary to detect the bottoms of the valleys at both ends, the tact time can be shortened.

[0024] In the present application, the shift device according to the above aspect may also have the following configuration.

[0025] (Additional note 1) That is, in the shift device according to the above aspect, a wall portion is provided in the valley portion of the end portion to prevent the positioning member from moving beyond the valley portion of the end portion, and is configured to reverse the movement of the positioning member so that the positioning member does not collide with the wall portion.

[0026] With this configuration, the movement of the positioning member can be reversed so that the positioning member does not collide with the wall portion, thereby more reliably preventing the positioning member from colliding with the wall portion.

[0027] (Additional note 2) In the shift device according to the aforementioned aspect, the design values ​​include an angle map indicating a relationship between the shift position and the rotation angle of the shift switching member corresponding to the output value of the output shaft rotation angle sensor.

[0028] With this configuration, the rotational angles of the motor corresponding to the bottoms of multiple valleys can be easily obtained (learned) based on an angle map showing the relationship between the shift position and the rotational angle of the shift switching member corresponding to the output value of the output shaft rotational angle sensor. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 2 is a block diagram showing a control configuration of a shift device according to an embodiment. [Figure 2] 1 is a perspective view showing a schematic overall configuration of a shift device according to an embodiment; [Figure 3] 3A and 3B are diagrams illustrating a structure of a detent plate that constitutes a shift device according to an embodiment. [Figure 4] FIG. 2 is a cross-sectional view showing an actuator unit that constitutes the shift device according to the embodiment. [Figure 5] 10 is a diagram showing the internal structure of a reduction mechanism in an actuator unit that constitutes a shift device according to an embodiment, with a gear housing removed from a main body. FIG. [Figure 6] 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 embodiment. FIG. [Figure 7] 4 is a diagram showing an engaged state of an intermediate gear (a driving force non-transmitting state) in an actuator unit that constitutes the shift device according to the embodiment. FIG. [Figure 8] 5 is a diagram showing the relationship between the output value (output voltage) of the output shaft rotation 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 embodiment. FIG. [Figure 9] FIG. 2 is a diagram illustrating the relationship between a rotating shaft and an output shaft of a motor. [Figure 10]FIG. 4 is a diagram illustrating a relationship between a first estimated value, a second estimated value, and a center of backlash in the shift device according to the embodiment. [Figure 11] FIG. 10 is a diagram for explaining design values ​​(angle map). [Figure 12] 10 is a flowchart illustrating a control process executed by the shift device to avoid collision of a detent spring with a wall portion. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, an embodiment will be described with reference to the drawings.

[0031] (Overall configuration of the shift device) First, the configuration of a shift device 100 according to this embodiment will be described with reference to Figures 1 to 12. In this specification, the terms "rotation angle of the motor" and "rotation angle of the rotor" have the same meaning.

[0032] As shown in FIG. 1, shift device 100 is mounted on a vehicle 110 such as an automobile. In vehicle 110, when a driver performs a shift operation via an operating unit 111 such as a shift lever, electrical shift control is performed on transmission mechanism 120. That is, the position of the shift lever is input to shift device 100 via a shift sensor 112 provided in operating unit 111. Then, based on a control signal transmitted from a dedicated ECU 50 provided in shift device 100, transmission mechanism 120 is switched to one of the shift positions P (parking), R (reverse), N (neutral), and D (drive), corresponding to the shift operation by the driver. This type of shift control is called shift-by-wire (SBW).

[0033] The shift device 100 includes an actuator unit 60 and a shift switching mechanism 70 driven by the actuator unit 60.

[0034] The shift switching mechanism 70 is mechanically connected to a manual spool valve (not shown) of a hydraulic valve body in the hydraulic control circuit 130 in the transmission mechanism 120 and to the parking mechanism 140. The shift switching mechanism 70 is configured so that the shift positions (P position, R position, N position, and D position) of the transmission mechanism 120 are mechanically switched by driving the shift switching mechanism 70.

[0035] The actuator unit 60 includes a motor 10, a speed reduction mechanism 20, a rotor rotation angle sensor 30 that detects the rotation angle of a rotor 11 of the motor 10, an output shaft rotation angle sensor 40 that detects the rotation angle of a detent plate 71 (output shaft 25), and an ECU 50. As shown in FIG. 2, the ECU 50 is a board component having electronic components mounted on a board 51. The output shaft rotation angle sensor 40 is configured, for example, with a Hall element. The rotation position (output angle) of the output shaft 25 is detected as a continuous voltage value by the output shaft rotation angle sensor 40.

[0036] The actuator unit 60 also includes a box-shaped main body 61 that houses the above-mentioned components of the actuator unit 60 and is fixed to the case of the speed change mechanism 120. The actuator unit 60 also includes an output shaft 25 that is connected to the output side of the speed reduction mechanism 20. The actuator unit 60 also includes a non-volatile memory 90 provided inside the main body 61 (see FIG. 1) (the memory 90 is not shown in FIG. 4).

[0037] (Detailed configuration of the shift switching mechanism) 2, the shift switching mechanism 70 includes a detent plate 71 (an example of a "shift switching member" in the claims) and a detent spring 72 (an example of a "positioning member" in the claims). The detent spring 72 is configured to hold the detent plate 71 at rotational angle positions corresponding to the P position, R position, N position, and D position, respectively.

[0038] 3, the detent plate 71 has a plurality of (four) valleys 80 (valleys 81-84) provided to correspond to the shift positions (P position, R position, N position, and D position). In detail, the plurality of (four) valleys 81-84 (valleys 80) include the parking position, reverse position, neutral position, and drive position as shift positions in the order of parking position, reverse position, neutral position, and drive position from one end 81b to the other end 84b of the plurality of (four) valleys 81-84.

[0039] The shift device 100 is configured to acquire (learn) the rotation angles of the motor 10 corresponding to the parking position, reverse position, neutral position, and drive position while the detent spring 72 is moved in order to pass through the parking position, reverse position, neutral position, and drive position. Details of the learning will be described later.

[0040] Note that the shift device 100 is configured to detect that, when the detent plate 71 is in any position other than the four shift positions of the parking position, reverse position, neutral position, and drive position, the detent plate 71 is in an indeterminate shift position where a design value DE, which will be described later, is not associated with the output value of the output shaft rotation angle sensor 40. In short, the indeterminate shift positions (the other positions of the detent plate 71 described above) are the three positions of the position between the parking position and the reverse position (peak portion 85), the position between the reverse position and the neutral position (peak portion 85), and the position between the neutral position and the drive position (peak portion 85).

[0041] The valleys 81 to 84 form a cam surface 71a on the detent plate 71, which has a continuous undulating shape. Adjacent valleys 80 (for example, valleys 81 and 82, or valleys 82 and 83) are separated by a peak 85 having a single peak T. The detent spring 72 has a base end 72a (see FIG. 2) fixed to a casing 121 (see FIG. 2) of the transmission mechanism 120, and a roller portion (pin) 73 attached to a free end 72b (see FIG. 2). The roller portion 73 of the detent spring 72 constantly presses against the cam surface 71a (at either the valleys 81 to 84 or the peak 85). The detent spring 72 establishes a shift position when fitted into one of the valleys 81 to 84.

[0042] 3, among the multiple valleys 80 included in detent plate 71, valley 81 located at one end 81b and valley 84 located at the other end 84b are provided with walls 81a and 84a, respectively, to prevent detent spring 72 from moving beyond valley 81 and valley 84. Specifically, wall 81a is provided in valley 81 located at the end of detent plate 71 in the direction of arrow A. Wall 84a is also provided in valley 84 located at the end of detent plate 71 in the direction of arrow B. Note that shift device 100 is configured to reverse the movement of detent spring 72 (drive of motor 10) at valley bottom V of the P position and valley bottom V of the D position so that detent spring 72 does not collide with walls 81a and 84a.

[0043] 2, the detent plate 71 is fixed to the lower end (Z2 side) of the output shaft 25, and rotates integrally with the output shaft 25 around the rotation axis C1. As a result, the roller portion 73 of the detent spring 72 slides along the cam surface 71a as the detent plate 71 rotates (swings) forward or backward in the direction of arrow A or the direction of arrow B, and the roller portion 73 is fitted into one of the valley portions 81 to 84 by the biasing force F of the detent spring 72. The detent spring 72 is configured so that the roller portion 73 selectively fits into one of the valley portions 81 to 84 of the detent plate 71, thereby holding the detent plate 71 at a rotation angle position corresponding to the P position, R position, N position, or D position, respectively. As a result, the P position, R position, N position, or D position is individually established.

[0044] The detent plate 71 also has an arm 87 and an arm 88. The park rod 75 is connected to the arm 87, and the manual valve rod 76 (see FIG. 3) is connected to the arm 88. When the detent plate 71 is rotated to a rotation angle position corresponding to the R position, the manual spool valve at the tip of the manual valve rod 76 is moved to a position corresponding to the R position in the hydraulic valve body, thereby forming a hydraulic circuit for the R position in the hydraulic control circuit unit 130 (see FIG. 1). For the other shift positions, as with the R position, the manual valve rod 76 (manual spool valve) is moved to a position corresponding to one of the shift positions as the detent plate 71 is rotated, thereby forming a hydraulic circuit corresponding to each shift position in the hydraulic control circuit unit 130.

[0045] (Detailed configuration of the parking mechanism) As shown in FIG. 2, the parking mechanism 140 includes a parking gear 141 connected to a crankshaft (not shown) of the engine 150 and a lock pole 142 that engages with the parking gear 141. The lock pole 142 moves between a locked position and an unlocked position as the park rod 75 moves. When the detent plate 71 is rotated to a rotation angle position corresponding to the P position, the lock pole 142 is rotated to the locked position about the rotation axis C2, and the protrusion 142a engages with the tooth bottom portion 141a of the parking gear 141. This restricts free rotation of the parking gear 141 and restricts rotation of the crankshaft. When the detent plate 71 is rotated to a rotation angle position corresponding to a shift position other than the P position (R, N, or D position), the lock pole 142 is rotated to the unlocked position, and the engagement between the lock pole 142 and the parking gear 141 is released.

[0046] (Detailed configuration of the actuator unit) Next, the detailed configuration of the actuator unit 60 will be described.

[0047] <Configuration of the actuator unit's "main body"> 4, the main body 61 is composed of a motor housing 62, a motor cover 63, and a gear housing 64. The motor housing 62 and motor cover 63, which are made of heat-resistant resin, are assembled together with their respective recesses 62a and 63a facing each other, thereby accommodating the motor 10 and ECU 50 in a motor chamber 65. The resin gear housing 64 is assembled to the motor housing 62 from the opposite side (Z2 side) so that its recesses 64a face each other, thereby accommodating the reduction mechanism 20 in a gear chamber 66.

[0048] A socket 62c having a terminal 52 is formed on an outer surface 62b on one side of the motor housing 62. The terminal 52 is electrically connected to the ECU 50 via a wiring 53. Power is supplied to the actuator unit 60 via a wiring cable (not shown) connected to the socket 62c. Intercommunication between the ECU 50 and an ECU 151 (see FIG. 1) that controls the engine 150 is also performed via the wiring cable. The ECU 50 is also electrically connected to the motor 10 (see FIG. 1), the rotor rotation angle sensor 30 (see FIG. 1), and the output shaft rotation angle sensor 40 (see FIG. 1).

[0049] <Structure of the actuator unit's "motor"> 4, the motor 10 is configured to include a rotor 11 rotatably supported relative to a motor housing 62, and a stator 12 disposed opposite the rotor 11 with a magnetic gap therebetween. The motor 10 is also configured to drive a detent plate 71.

[0050] The motor 10 is a surface permanent magnet (SPM) three-phase motor in which permanent magnets are incorporated into the surface of the rotor 11. Specifically, the rotor 11 has a shaft pinion 11a, a rotor core 11b, and a gear portion 11c.

[0051] The rotor 11 has permanent north-pole magnets and south-pole magnets attached alternately at equal angular intervals (45°) around the rotation axis C1 on the surface of the rotor core 11b. Therefore, the motor 10 has eight poles.

[0052] The shaft pinion 11a has an upper end (Z1 side) rotatably supported by a bearing member 1 arranged in the rotary shaft support portion 63b of the motor cover 63, and a lower end (Z2 side) rotatably supported by a bearing member 2 of the output bearing portion 26, which is rotatably supported by a bearing member 3 press-fitted into the output shaft support portion 64b. The bearing member 2 is arranged along the inner periphery of a recess in the upper end (Z1 side) of the output bearing portion 26. As a result, the shaft pinion 11a of the rotor 11 and the output shaft 25 rotate around the same rotation axis C1.

[0053] The gear portion 11c is formed integrally with the shaft pinion 11a in an outer peripheral region extending from the center to the lower end (Z2 side) of the shaft pinion 11a. The gear portion 11c has a helical gear groove.

[0054] As shown in FIG. 4, the stator 12 has a stator core 13 fixed in the motor chamber 65 of the motor housing 62, and excitation coils (not shown) of multiple phases (U phase, V phase, and W phase) that generate magnetic force when current is applied.

[0055] As shown in FIG. 4, the stator core 13 integrally includes a substantially cylindrical main body 13a and a plurality of (four) teeth 13b projecting from the inner wall surface of the main body 13a toward the shaft center, the main body 13a being coaxial with the shaft pinion 11a of the rotor 11. A pair of the teeth 13b, located on opposite radial sides of the shaft center, each have a through hole formed parallel to the shaft pinion 11a. Rod-shaped support shafts 67a and 67b, which are inserted into through holes in the motor housing 62, extend through the through holes. The rear ends (upper ends in FIG. 4) of the support shafts 67a and 67b are fitted into the recesses 63c of the motor cover 63, and the front ends (lower ends in FIG. 4) of the support shafts 67a and 67b are fitted into the recesses 64c of the gear housing 64. This fixes the stator 12 within the motor chamber 65. The support shaft 67a, the support shaft 67b and the shaft pinion 11a are arranged so that their axes are parallel to each other along the Z direction.

[0056] <Configuration of the "reduction mechanism" of the actuator unit> The speed reduction mechanism 20 is configured to rotate the detent plate 71 while reducing the rotational speed transmitted from the motor 10. Specifically, as shown in Figures 4 and 5, the speed reduction mechanism 20 includes a gear portion 11c of the rotor 11, an intermediate gear 21 having a gear portion 21a meshing with the gear portion 11c, an intermediate gear 22 that is arranged on the lower surface side (Z2 side) of the same axis as the intermediate gear 21 and engages with the intermediate gear 21, and a final gear 23 having a gear portion 23a meshing with the gear portion 22a of the intermediate gear 22. The driving force of the motor 10 is transmitted in this order through the gear portion 11c, the intermediate gear 21, the intermediate gear 22, and the final gear 23, and is finally transmitted to the output shaft 25 via the output bearing 26.

[0057] The intermediate gear 21 is provided on the side of the motor 10 that drives the detent plate 71. The intermediate gear 22 is provided on the side of the detent plate 71 and rotates as the intermediate gear 21 rotates. The shaft pinion 11a has a lower end supported by a bearing member 2, so that the gear portion 11c crosses the gear chamber 66 in the vertical direction (Z direction). The intermediate gear 21 is rotatably supported by a bearing member 4 with respect to a support shaft 67a inserted into a through hole in the motor housing 62. The intermediate gear 22 is rotatably supported by a substantially cylindrical bearing member 5 fitted into the support shaft 67a. The intermediate gears 21 and 22 are coaxially stacked.

[0058] As shown in FIGS. 6 and 7, the intermediate gear 21 has a plurality of (six) elongated holes 21e with their major axes extending along the circumferential direction between the rotation center and the outer periphery (gear portion 21a). The elongated holes 21e are arranged at 60° intervals from one another in the circumferential direction. The intermediate gear 22 has an elliptical main body portion 22b on which the gear portion 22a is provided, and has a plurality of (two) cylindrical engaging protrusions 22e protruding upward from the upper surface (Z1 side) of the main body portion 22b opposite the gear portion 22a. The engaging protrusions 22e are arranged on the periphery of both sides in the major axis direction of the main body portion 22b. When the intermediate gear 22 is arranged adjacent to the intermediate gear 21 from below to above (Z1 side), each of the engaging protrusions 22e arranged at 180° intervals from one another is configured to be inserted into (engaged with) the two elongated holes 21e of the corresponding intermediate gear 21.

[0059] The engaging protrusion 22e is fitted into the elongated hole 21e of the intermediate gear 21 with a backlash S of a predetermined size (circumferential length). That is, as shown in Fig. 7, the intermediate gear 21 and the intermediate gear 22 are configured to be allowed to rotate freely relative to each other by the amount of backlash S (predetermined angular width) in the circumferential direction that occurs between the engaged engaging protrusion 22e and the elongated hole 21e. In short, the backlash S is a predetermined amount of gap between the engaging protrusion 22e and the elongated hole 21e that prevents the driving force from being transmitted from the motor 10 to the detent plate 71.

[0060] Therefore, the intermediate gears 21 and 22 do not always rotate integrally, but the rotation transmitted to the intermediate gear 21 is transmitted to the intermediate gear 22 while allowing the intermediate gear 21 to rotate freely relative to the intermediate gear 22 in one direction (the direction of arrow A) or the other direction (the direction of arrow B) within a predetermined angular range. Note that Fig. 6 shows a state in which the driving force can be transmitted from the intermediate gear 21 to the intermediate gear 22, and Fig. 7 shows a state in which the driving force cannot be transmitted from the intermediate gear 21 to the intermediate gear 22.

[0061] In this embodiment, shift device 100 is configured to detect a state in which driving force is not transmitted from motor 10 to detent plate 71 due to backlash S, based on output values ​​of rotor rotation angle sensor 30 and output shaft rotation angle sensor 40, and design value DE (see FIGS. 1 and 11), thereby detecting valley bottoms V of valleys 81, 84 of end portions 81b, 84b. Shift device 100 is configured to acquire (learn) the rotation angles of motor 10 corresponding to the valley bottoms V of the plurality of valleys 81-84 by reversing the movement of detent plate 71. Details of this learning will be described later. The shift device may be configured to acquire the motor rotation angles corresponding to the bottoms of the plurality of valleys by reciprocating the detent spring between the two ends of the plurality of valleys, that is, by reversing the rotation direction of the detent plate at a position just before the two ends of the plurality of valleys (inside the two ends of the plurality of valleys), rather than detecting the bottoms of the valleys at both ends of the plurality of valleys based on the output values ​​of the rotor rotation angle sensor and the output shaft rotation angle sensor and the design value. In this case, the tact time can be shortened because it is not necessary to detect the bottoms of the valleys at both ends.

[0062] In other words, when the detent plate 71 rotating in the direction of arrow B moves to the bottom V of the valley 81 at the end 81b where the wall 81a is provided (when the detent spring 72 gets stuck in the valley 81), the shift device 100 reverses the rotation of the detent plate 71 (the rotation of the motor 10) to prevent the detent spring 72 from colliding with the wall 81a. Also, when the detent plate 71 rotating in the direction of arrow A moves to the bottom V of the valley 84 at the end 84b where the wall 84a is provided (when the detent spring 72 gets stuck in the valley 84), the shift device 100 reverses the rotation of the detent plate 71 (the rotation of the motor 10) to prevent the detent spring 72 from colliding with the wall 84a. The flow of the control process for preventing the detent spring 72 from colliding with the walls 81a, 84a will be described later.

[0063] As shown in FIG. 11 , the design value DE is an angle map showing the relationship between the shift positions (P position, R position, N position, and D position) and the rotational angle of the detent plate 71 corresponding to the output value of the output shaft rotation angle sensor 40. In other words, the shift device 100 can determine which shift position the detent plate 71 is in while rotating it using the design value DE. At each shift position, the output value of the output shaft rotation angle sensor 40 is maintained substantially constant. Therefore, the range of output values ​​(voltage value range) of the output shaft rotation angle sensor 40 corresponding to each shift position is significantly smaller than the range of output values ​​(voltage value range) of the output shaft rotation angle sensor 40 corresponding to the indefinite shift position. The design value DE is stored in the memory 50 a (see FIG. 1 ) included in the ECU 50 of the actuator unit 60. The design value may also be stored in another memory, such as a non-volatile memory of the actuator unit.

[0064] As shown in FIG. 5, the gear portion 22a of the intermediate gear 22 meshes with the gear portion 23a of the fan-shaped final gear 23, which is assembled so as to rotate integrally with the output bearing portion 26, while sharing the same rotation axis C1 as the output bearing portion 26. The gear portion 23a is formed as an internal gear on the inside along the outer periphery of a substantially arc-shaped insertion hole 23b provided in the final gear 23. The gear portion 23a is formed of a gear with a larger diameter than the gear portion 22a. The final gear 23 has a fitting hole 23c whose rotation center is located at the pivot point of the fan shape, to which the output bearing portion 26 is fixed. The reduction mechanism 20 is configured so that the rotation of the shaft pinion 11a is reduced on the output shaft 25 side by the intermediate gear 21, the intermediate gear 22, and the final gear 23.

[0065] The speed reduction mechanism 20 is configured to have a reduction ratio of 1:50. That is, the output shaft 25 is configured to rotate once when the rotor 11 rotates 50 times (the motor 10 has 24 x 50 = 1200 current-carrying steps). Therefore, in the motor 10, the rotor 11 rotates 15° in one current-carrying step, and the output shaft 25 rotates 0.3° (= 15 / 50).

[0066] Furthermore, a plurality of axially extending longitudinal grooves (serrations) 26a are formed on the inner periphery of the recess at the lower end (Z2 side) of the output bearing portion 26. Furthermore, a plurality of axially extending longitudinal grooves (serrations) 25a are formed on the outer periphery of the upper end (Z1 side) of the output shaft 25 (see FIG. 4). This allows the longitudinal grooves 25a of the output shaft 25 to be fitted and connected to the longitudinal grooves 26a of the output bearing portion 26 so as to be able to transmit torque at an appropriate rotational angle position. Therefore, the output shaft 25, to which the detent plate 71 is fixed at the lower end (Z2 side), is assembled to the actuator unit 60 at an appropriate rotational angle position.

[0067] (Relationship between the output value of the output shaft rotation angle sensor and the output value of the rotor rotation angle sensor) Next, the relationship between the movement of the shift position and the output value of the output shaft rotation angle sensor 40 and the output value of the rotor rotation angle sensor 30 will be described.

[0068] As shown in Fig. 8, assuming that the initial position of the shift position is the P position, as the number of rotations of the motor 10 increases (0, 1, 2, ..., 7), the detent plate 71 connected to the output shaft 25 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 72 fits into the valley portion 80 in the order of valley portions 81 to 84. The output value of the output shaft rotation angle sensor 40 increases as the number of rotations of the motor 10 increases.

[0069] For example, assume that the roller portion 73 is currently fitted into the valley portion 81 (position P) (section 1). When the motor 10 (see FIG. 1) is driven, the detent plate 71 is rotated in the direction of arrow A via the speed reduction mechanism 20 (see FIG. 1). A predetermined amount of backlash S (see FIG. 7) is provided between the intermediate gear 21 and the intermediate gear 22. Therefore, when the roller portion 73 is completely fitted into the valley bottom V of the valley portion 81 (see section 1 in FIG. 9), the intermediate gear 21 rotates as the rotor 11 rotates, but the engaging protrusion 22e is engaged within the elongated hole 21e by the backlash S in a manner that prevents transmission of driving force, so the intermediate gear 22 does not rotate. As a result, in section 1, the rotation angle (rad) of the rotor 11 detected by the rotor rotation angle sensor 30 (see FIG. 1) increases linearly, while the voltage level corresponding to the rotation angle of the output shaft 25 detected by the output shaft rotation angle sensor 40 (see FIG. 1) remains constant.

[0070] Then, in section 2, one end of the elongated hole 21e of the intermediate gear 21 engages with the engaging protrusion 22e of the intermediate gear 22 so as to be able to transmit driving force (see section 2 in FIGS. 6 and 9). Therefore, the driving force of the motor 10 is transmitted to the output shaft 25 (see FIG. 2) via the gear portion 11c, the intermediate gear 21, the intermediate gear 22, and the final gear 23 (see FIG. 4). As a result, as the detent plate 71 rotates in the direction of arrow A, the roller portion 73 moves up the slope on the side of the valley portion 82 (R position) of the valley portion 81 (P position) toward the peak portion 85. The motor 10 rotates approximately one revolution at the P position (section 1). Then, in section 2, the rotation angle (rad) of the rotor 11 detected by the rotor rotation angle sensor 30 (see FIG. 1) increases linearly. Furthermore, the voltage level corresponding to the rotation angle of the output shaft 25 detected by the output shaft rotation angle sensor 40 (see FIG. 1) increases at a constant rate. In addition, the engagement state of the intermediate gears 21 and 22 in this state corresponds to the state shown in FIG.

[0071] Then, in section 3, after the roller portions 73 climb over the peak portion 85 at the boundary between the valley portion 81 (position P) and the valley portion 82 (position R), the detent plate 71 naturally rotates in the direction of arrow A ahead of the motor 10 (intermediate gear 21). That is, the detent plate 71 is constantly biased toward the valley portion 82 by the roller portions 73, and this biasing force F (see FIG. 3) causes the detent plate 71 to rotate in the direction of arrow A ahead of the motor 10 within the range of the backlash S of the elongated hole 21e. The roller portions 73 then drop toward the valley bottom V of the valley portion 82 (see section 3 in FIG. 9). At this time, the rotation angle of the rotor 11 increases, while the voltage level corresponding to the rotation angle of the output shaft 25 rapidly increases as the roller portions 73 drop (suck) toward the valley bottom V.

[0072] The operation of moving the shift position from the R position to the N position and from the N position to the D position is the same as the operation of moving from the P position to the R position described above.

[0073] Then, the rotation direction of the motor 10 is reversed. As a result, the shift position moves to the N position via the D position (section 4), section 5, and section 6. The operation in the D position (section 4) is the same as the operation in the above-mentioned section 1. That is, the rotation angle (rad) of the rotor 11 detected by the rotor rotation angle sensor 30 (see FIG. 1) decreases linearly, while the voltage level corresponding to the rotation angle of the output shaft 25 detected by the output shaft rotation angle sensor 40 (see FIG. 1) is constant. The operation in the above-mentioned section 5 is the same as the operation in the above-mentioned section 2. That is, in the section 5, the rotation angle of the rotor 11 decreases linearly, and the voltage level corresponding to the rotation angle of the output shaft 25 decreases at a constant rate. The operation in the above-mentioned section 6 is the same as the operation in the above-mentioned section 3. That is, the rotation angle of the rotor 11 decreases, while the voltage level corresponding to the rotation angle of the output shaft 25 decreases rapidly as the roller portion 73 falls (sucks) into the valley bottom V.

[0074] Here, in order to improve the positioning accuracy of the detent spring 72 with respect to the detent plate 71 (the valley bottom V of the valley portion 80), it is necessary to accurately grasp the rotation angle of the motor 10 (the rotor 11) when the detent spring 72 is positioned at the valley bottom V of the valley portion 80. Therefore, the shift device 100 is configured to acquire (learn) the rotation angle of the motor 10 (the rotor 11) that corresponds to the valley bottom V of the plurality of valley portions 81 to 84 (the valley portion 80). Such learning of the shift device 100 is performed, for example, before shipping from a factory.

[0075] (Shift device learning operation) Next, the acquisition (learning) of the rotation angle of the motor 10 (rotor 11) corresponding to the bottom V (center of backlash S) of the valley portion 80 at each of a plurality of shift positions (P position, R position, N position, and D position) will be described. Note that the acquisition of the rotation angle of the motor 10 corresponding to the bottom V is performed by, for example, the ECU 50.

[0076] 10 , first, the detent spring 72 (roller portion 73) is moved so as to successively pass through the plurality of valley portions 80. Then, the shift device 100 is configured to obtain the rotation angle of the motor 10 corresponding to the valley bottom V of the plurality of valley portions 81-84 by causing the detent spring 72 to reciprocate once between both end portions 81 b, 84 b of the plurality of valley portions 81-84.

[0077] As a specific example, the shift device 100 starts moving the detent spring 72 (detent plate 71) (driving the motor 10) from the N position toward the P position. When the detent spring 72 reaches the P position, the shift device 100 reverses the movement of the detent spring 72 (detent plate 71) (driving the motor 10) from the P position toward the D position. When the detent spring 72 reaches the D position, the shift device 100 reverses the movement of the detent spring 72 (detent plate 71) (driving the motor 10) from the D position toward the P position. When the detent spring 72 reaches the N position again, the shift device 100 stops the movement of the detent spring 72 (detent plate 71) (driving the motor 10).

[0078] Here, in order to stop the driving of the motor 10, the shift device 100 is configured to, when moving the detent spring 72 so that it passes through the multiple valleys 81 to 84, determine based on the output values ​​of the rotor rotation angle sensor 30 and the output shaft rotation angle sensor 40 and the design value DE that, after the motor 10 starts to drive, the rotation direction (direction of arrow B) is the same as when the motor 10 started to drive, and if the valley bottom V (N position) of the valley 83 that is the same as the valley bottom V (N position) of the valley 83 detected when the motor 10 started to drive is detected again, that the rotation angle of the motor 10 corresponding to the valley bottom V of the multiple (four) valleys 81 to 84 has been acquired, and stop the driving of the motor 10.

[0079] The shift device 100 detects the width of backlash S included in the speed reduction mechanism 20 based on the output value of the output shaft rotation angle sensor 40 and the output value of the rotor rotation angle sensor 30 while the detent spring 72 is being moved. The output value of the output shaft rotation angle sensor 40 is a voltage (V). The output value of the rotor rotation angle sensor 30 is a rotation angle (rad). The detected output values ​​of the output shaft rotation angle sensor 40 and the rotor rotation angle sensor 30 are represented by thick lines in FIG. 10.

[0080] The shift device 100 is configured to continuously move the detent spring 72 between the P position and the D position. "Continuously" means that the detent spring 72 moves between the P position and the D position (between one end 81b and the other end 84b) without reversing direction along the way. By continuously moving, the detent spring 72 makes one reciprocating movement through the multiple valleys 80 of the detent plate 71.

[0081] The output values ​​of the output shaft rotation angle sensor 40 and the rotor rotation angle sensor 30 detected when the detent spring 72 rotates in the direction of arrow A (when it moves in the direction from position P to position D) are represented by the thick line on straight line L1 in Figure 10.

[0082] In addition, the output values ​​of the output shaft rotation angle sensor 40 and the rotor rotation angle sensor 30 detected when the detent spring 72 rotates in the direction of arrow B (when it moves in the direction from position D to position P) are represented by the thick line on line L2 in Figure 10.

[0083] In this embodiment, the width of the backlash S included in the reduction mechanism 20 is detected based on the output value of the output shaft rotation angle sensor 40 and the output value of the rotor rotation angle sensor 30 during the movement section in which the detent spring 72 moves from the bottom V of the valley portion 80 of the detent plate 71 to the top T of the peak portion 85. Note that the width of the backlash S refers to the width W between the engaging protrusion 22e and the elongated hole 21e in a state in which the backlash S is eliminated (a state in which driving force can be transmitted from the intermediate gear 21 to the intermediate gear 22), as shown in FIG.

[0084] 9, the section of movement (sections 2 and 5) in which the detent spring 72 moves from the bottom V of the valley portion 80 of the detent plate 71 to the peak T of the peak portion 85 is a section in which the backlash S between the intermediate gear 21 and the intermediate gear 22 is eliminated (see FIG. 6), and in which the intermediate gear 22 rotates in conjunction with the rotation of the intermediate gear 21. The section of movement in which the detent spring 72 moves from the bottom V to the peak T includes section 2 in which the detent plate 71 rotates in the direction of arrow A, and section 5 in which the detent plate 71 rotates in the direction of arrow B.

[0085] In addition, in this embodiment, as shown in FIG. 10, the width of the backlash S is detected based on the output value of the output shaft rotation angle sensor 40 and the output value of the rotor rotation angle sensor 30 in the movement section when the motor 10 is rotated in the direction of arrow A (an example of the first direction in the claims) and when it is rotated in the direction of arrow B (an example of the second direction in the claims) opposite to the direction of arrow A.

[0086] Specifically, as described above, the width of backlash S is detected based on the output value of output shaft rotation angle sensor 40 and the output value of rotor rotation angle sensor 30 in section 2, where backlash S is eliminated when motor 10 is rotated in the direction of arrow A, and section 5, where backlash S is eliminated when motor 10 is rotated in the direction of arrow B. Section 2 includes section 2 when detent spring 72 moves from the P position to the R position, section 2 when detent spring 72 moves from the R position to the N position, and section 2 when detent spring 72 moves from the N position to the D position. Section 5 includes section 5 when detent spring 72 moves from the D position to the N position, section 5 when detent spring 72 moves from the N position to the R position, and section 5 when detent spring 72 moves from the R position to the P position.

[0087] <Calculation of the first estimated value (line L1)> The calculation of the first estimated value (straight line L1) will be described. In this embodiment, the first estimated value (straight line L1) of the rotor rotation angle sensor 30 relative to the output value of the output shaft rotation angle sensor 40 is calculated from the output values ​​of the output shaft rotation angle sensor 40 and the rotor rotation angle sensor 30 in multiple movement sections when the motor 10 is rotated in the direction of arrow A.

[0088] Specifically, the first estimated value is calculated from the output value of the output shaft rotation angle sensor 40 and the output value of the rotor rotation angle sensor 30 in three sections 2 (section 2 when the detent spring 72 moves from the P position to the R position, section 2 when the detent spring 72 moves from the R position to the N position, and section 2 when the detent spring 72 moves from the N position to the D position) when the motor 10 is rotated in the direction of arrow A. The three sections 2 are sections when the motor 10 attempts to climb over the peak 85 toward the apex T (see FIG. 3).

[0089] Specifically, in this embodiment, the first estimated value is calculated by linearly approximating the output value of the rotor rotation angle sensor 30 relative to the output value of the output shaft rotation angle sensor 40 in multiple movement sections (three sections 2, the thick lines on the line L1 in FIG. 10 ) when the motor 10 is rotated in the direction of arrow A. That is, with the output value (voltage) of the output shaft rotation angle sensor 40 represented on the horizontal axis and the output value (rotation angle) of the rotor rotation angle sensor 30 represented on the vertical axis, the relationship between the voltage (V) and the rotation angle (rad) in the three sections 2 is linearly approximated. In this way, a line L1 is obtained as the first estimated value. That is, the slope (hereinafter referred to as a1) and intercept (hereinafter referred to as b1) of the line L1 are calculated. Note that in practice, the vertical axis represents the integrated value of the rotation angle of the motor 10 (i.e., 2π × the number of rotations of the motor 10 + the rotation angle).

[0090] <Calculation of the second estimated value (line L2)> The calculation of the second estimated value (straight line L2) will be described. In this embodiment, the second estimated value (straight line L2) of the rotor rotation angle sensor 30 relative to the output value of the output shaft rotation angle sensor 40 is calculated from the output values ​​of the output shaft rotation angle sensor 40 and the rotor rotation angle sensor 30 in multiple movement sections when the motor 10 is rotated in the direction of arrow B.

[0091] Specifically, the second estimated value is calculated from the output value of the output shaft rotation angle sensor 40 and the output value of the rotor rotation angle sensor 30 in three sections 5 (section 5 when the detent spring 72 moves from the D position to the N position, section 5 when the detent spring 72 moves from the N position to the R position, and section 5 when the detent spring 72 moves from the R position to the P position) when the motor 10 is rotated in the direction of arrow B. The three sections 5 are sections when the motor 10 attempts to climb over the peak 85 toward the apex T (see FIG. 3).

[0092] More specifically, in this embodiment, the second estimated value is calculated by linearly approximating the output value of the rotor rotation angle sensor 30 relative to the output value of the output shaft rotation angle sensor 40 in multiple movement sections (three sections 5) when the motor 10 is rotated in the direction of arrow B. That is, with the horizontal axis representing the output value (voltage) of the output shaft rotation angle sensor 40 and the vertical axis representing the output value (rotation angle) of the rotor rotation angle sensor 30, the relationship between the voltage (V) and the rotation angle (rad) in the three sections 5 is linearly approximated. In this way, a straight line L2 is obtained as the second estimated value. That is, the slope (hereinafter referred to as a2) and intercept (hereinafter referred to as b2) of the straight line L2 are calculated.

[0093] (The difference between the first and second estimated values ​​is detected as the width W of the backlash.) The difference between the first estimated value and the second estimated value is detected as the width of the backlash S, and the central value of the width of the backlash S is set as the center of the backlash S. The width of the backlash S is a predetermined width of the backlash S (see FIG. 6) that is provided in advance between the intermediate gear 21 and the intermediate gear 22. Specifically, the width W between the first estimated value (straight line L1) calculated by linear approximation and the second estimated value (straight line L2) calculated by linear approximation is detected as the width of the backlash S. In other words, because a predetermined width of the backlash S is provided in advance between the intermediate gear 21 and the intermediate gear 22, a difference occurs in the rotation angle (vertical axis) of the motor 10 even if the output value (horizontal axis) of the output shaft rotation angle sensor 40 is the same. This difference can be regarded as the width of the backlash S.

[0094] <Acquisition of motor rotation angles corresponding to the bottoms of multiple valleys> In this embodiment, the rotation angle of the rotor 11 corresponding to the center of the backlash S is calculated based on the width of the detected backlash S. Specifically, the center state between the state in which the backlash S is eliminated when the motor 10 is rotated in the direction of arrow A and the state in which the backlash S is eliminated when the motor 10 is rotated in the direction of arrow B (i.e., the center of the width of the backlash S) can be regarded as the center of the backlash S.

[0095] That is, a straight line L3 as the center of the backlash S, which passes through the middle between the straight line L1 as the first estimated value and the straight line L2 as the second estimated value, is acquired as the rotation angle of the rotor 11 corresponding to the center of the backlash S. That is, the slope (hereinafter referred to as a3) and intercept (hereinafter referred to as b3) of the straight line L3 are calculated. In addition, the straight line L3 represents the relationship between the output value of the output shaft rotation angle sensor 40 and the output value of the rotor rotation angle sensor 30 (the rotation angle of the rotor 11) corresponding to the center of the backlash S.

[0096] In this embodiment, the rotation angle of the motor 10 corresponding to the center of the backlash S is obtained based on the association between the rotation angle of the rotor 11 corresponding to the calculated center of the backlash S and the output value of the output shaft rotation angle sensor 40 corresponding to the bottom V of the valley portion 80.

[0097] Specifically, output values ​​of the output shaft rotation angle sensor 40 are acquired in a plurality of sections 1 (sections 1 corresponding to the P position, R position, N position, and D position) when the motor 10 is rotated in the direction of arrow A. Note that the output value of the output shaft rotation angle sensor 40 is a constant value in each of the plurality of sections 1. Specifically, the output values ​​of the output shaft rotation angle sensor 40 corresponding to the P position, R position, N position, and D position are E1, E2, E3, and E4, respectively.

[0098] Furthermore, output values ​​of the output shaft rotation angle sensor 40 are acquired in a plurality of sections 4 (sections 4 corresponding to the D position, N position, R position, and P position) when the motor 10 is rotated in the direction of arrow B. Note that the output value of the output shaft rotation angle sensor 40 is a constant value in each of the plurality of sections 4. Specifically, the output values ​​of the output shaft rotation angle sensor 40 corresponding to the D position, N position, R position, and P position are E4, E3, E2, and E1, respectively. In other words, the output value of the output shaft rotation angle sensor 40 in section 1 and the output value of the output shaft rotation angle sensor 40 in section 4 at the same shift position are substantially the same.

[0099] Then, the rotation angle of motor 10 corresponding to section 1 (or section 4) on straight line L3 is obtained. Specifically, rotation angles θ1, θ2, θ3, and θ4 of motor 10 corresponding to output values ​​E1, E2, E3, and E4 of output shaft rotation angle sensor 40, respectively, are obtained. As a result, rotation angles θ1, θ2, θ3, and θ4 of motor 10 corresponding to the bottom V (center of backlash S) of each of the P position, R position, N position, and D position are obtained.

[0100] Therefore, as described above, the vertical axis of Figure 10 represents the integrated value of the rotation angle of motor 10 (= 2π x number of rotations of motor 10 + rotation angle), so the number of rotations of motor 10 and the rotation angle at that number of rotations corresponding to each valley bottom V (center of backlash S) of the P position, R position, N position, and D position (multiple valley portions 81 to 84) are obtained.

[0101] The learning results are then stored in nonvolatile storage unit 90 (see FIG. 1). Specifically, a linearly approximated first estimated value (straight line L1), a linearly approximated second estimated value (straight line L2), and a center of backlash S (straight line L3), which is the median value between the linearly approximated first estimated value and the linearly approximated second estimated value, are stored in nonvolatile storage unit 90. In addition, the center of backlash S and the output values ​​of output shaft rotation angle sensor 40 and rotor rotation angle sensor 30, which correspond to bottoms V of multiple valleys 81-84, are stored in nonvolatile storage unit 90.

[0102] (Control process to prevent the detent spring from colliding with the wall) 12, a control process performed by the shift device 100 to avoid collision of the detent spring 72 with the walls 81a, 84a will be described. This control process is executed, for example, by the ECU 50 of the shift device 100. Note that, as an example, the movement (rotation) of the detent plate 71 is assumed to start from the bottom V of the valley portion 83 at the N position.

[0103] First, in step S1, the rotation direction of the motor 10 is set to the direction of arrow B, and driving of the motor 10 is started. That is, in step S1, the rotation direction of the motor 10 is set to the direction of arrow B so that the detent plate 71 (detent spring 72) moves from the N position to the P position, and driving of the motor 10 (movement of the detent plate 71) is started. Then, the process proceeds to step S2.

[0104] Next, in step S2, the current shift position is determined from the design value DE (see FIG. 11) and the output value of the output shaft rotation angle sensor 40. That is, in step S2, it is determined whether the detent plate 71 is in the P position, R position, N position, D position, or an indeterminate shift position. Then, the process proceeds to step S3.

[0105] 11, when the detent plate 71 is in the P position, this specifically means that the output value of the output shaft rotation angle sensor 40 is in the range of A1 to A2 (A1 or more and A2 or less) [V]. The range of A1 to A2 [V] is a range with a small margin around E1 [V] (see FIG. 8) as the center voltage.

[0106] 11, when the detent plate 71 is in the R position, the N position, or the D position, the output value of the output shaft rotation angle sensor 40 is in the ranges of B1 to B2 (B1 or more and B2 or less) [V], C1 to C2 (C1 or more and C2 or less) [V], and D1 to D2 (D1 or more and D2 or less) [V], respectively. The range of B1 to B2 [V] is a range with a center voltage of E2 [V] (see FIG. 8) and a slight margin around E2 [V]. The range of C1 to C2 [V] is a range with a center voltage of E3 [V] (see FIG. 8) and a slight margin around E3 [V]. The range of D1 to D2 [V] is a range with a center voltage of E4 [V] (see FIG. 8) and a slight margin around E4 [V].

[0107] Next, in step S3, it is determined whether or not the detent plate 71 is located at the valley bottom V based on the output value of the output shaft rotation angle sensor 40 and the output value of the rotor rotation angle sensor 30. That is, in step S3, it is determined whether or not the detent plate 71 is located at the valley bottom V of any of the plurality of valleys 81 to 84, regardless of the shift position (P position, R position, N position, D position, or indefinite shift position). In short, in step S3, while the motor 10 is driving and the output value of the rotor rotation angle sensor 30 is fluctuating, it is determined whether or not the output value of the output shaft rotation angle sensor 40 is in a substantially constant state due to the influence of the backlash S. Then, the process proceeds to step S4.

[0108] Next, in step S4, it is determined whether or not it was determined in step S2 that the detent plate 71 is in position P and whether or not it was determined in step S3 that the detent plate 71 is located at bottom V. That is, in step S4, it is determined whether or not the detent spring 72 will collide with wall portion 81a if the movement of detent plate 71 (driving of motor 10) in the direction of arrow B continues. Then, in step S4, if it is determined in step S2 that the detent plate 71 is in position P and it is determined in step S3 that the detent plate 71 is located at bottom V, the process proceeds to step S5; otherwise, the process proceeds to step S6.

[0109] Next, in step S5, the rotation direction of motor 10 is reversed from the direction of arrow B to the direction of arrow A. That is, in step S5, the rotation direction of motor 10 is set to the direction of arrow A so that detent plate 71 moves from position P to position D (so that detent spring 72 moves further away from wall portion 81a to avoid collision with wall portion 81a), and motor 10 is driven (detent plate 71 moves). Then, the process proceeds to step S8.

[0110] Furthermore, in step S6, it is determined whether or not it was determined in step S2 that the detent plate 71 is in position D and whether or not it was determined in step S3 that the detent plate 71 is located at the valley bottom V. That is, in step S6, it is determined whether or not a situation exists in which the detent spring 72 will collide with the wall portion 84a if the movement of the detent plate 71 (driving of the motor 10) in the direction of arrow A continues. Then, in step S6, if it is determined in step S2 that the detent plate 71 is in position D and it is determined in step S3 that the detent plate 71 is located at the valley bottom V, the process proceeds to step S7; otherwise, the process proceeds to step S8.

[0111] Next, in step S7, the rotation direction of the motor 10 is reversed from the direction of arrow A to the direction of arrow B. That is, in step S7, the rotation direction of the motor 10 is set to the direction of arrow B so that the detent plate 71 moves from position D to position P (so that the detent plate 71 moves further away from wall portion 84a to avoid collision of the detent spring 72 with wall portion 84a), and the motor 10 is driven (the detent plate 71 moves). Then, the process proceeds to step S8.

[0112] Next, in step S8, it is determined whether the learning operation is complete. That is, in step S8, it is determined whether the detent plate 71 has made one reciprocating movement between the P position and the D position. More specifically, in step S8, it is determined based on the output values ​​of the rotor rotation angle sensor 30 and the output shaft rotation angle sensor 40 and the design value DE whether, after the motor 10 starts to drive, a bottom V (N position) of the valley 83 (N position) that is the same as the bottom V of the valley 83 (N position) that was initially detected when the motor 10 started to drive has been detected again in the same rotation direction (the direction of arrow B) as when the motor 10 started to drive. Then, if it is determined in step S8 that the learning operation is complete, the process proceeds to step S9. If not, the process returns to step S2.

[0113] Next, in step S9, the driving of the motor 10 (movement of the detent plate 71) is stopped. This completes the learning for acquiring the rotation angle of the motor 10 corresponding to the valley bottoms V of the plurality of valleys 81-84.

[0114] (Effects of the embodiment) In this embodiment, the following effects can be obtained.

[0115] In this embodiment, as described above, when the detent spring 72 is moved to pass through the multiple valleys 81, 82, 83, and 84, the valley bottoms V of the valleys 81 and 84 at the ends 81b and 84b of the multiple valleys 81, 82, 83, and 84 are detected based on the output values ​​of the rotor rotation angle sensor 30 and the output shaft rotation angle sensor 40 and the design value DE that associates the output value of the output shaft rotation angle sensor 40 with the shift position, and the movement of the detent spring 72 is reversed, thereby obtaining (learning) the rotation angle of the motor 10 corresponding to the valley bottoms V of the multiple valleys 81, 82, 83, and 84. As a result, during learning, the valley bottoms V of the valleys 81, 84 (valleys 81, 84 where wall portions 81a, 84a are provided) at the end portions 81b, 84b of the plurality of valleys 81, 82, 83, 84 are detected based on the output values ​​of the rotor rotation angle sensor 30 and the output shaft rotation angle sensor 40 and the design value DE that associates the output value of the output shaft rotation angle sensor 40 with the shift position, and the movement of the detent spring 72 can be reversed. Therefore, when the valley bottoms V of the valleys 81, 84 (valleys 81, 84 where wall portions 81a, 84a are provided) at the end portions 81b, 84b are detected, the movement direction of the detent spring 72 can be changed so that the detent spring 72 is further separated from the wall portions 81a, 84a. As a result, learning can be performed without the detent spring 72 colliding with the wall portions 81a, 84a provided at the valleys 81, 82, 83, 84 of the end portions 81b, 84b. Therefore, it is possible to prevent a decrease in the durability of the transmission mechanism 120 that is mechanically connected to the detent plate 71, and it is also possible to prevent a decrease in the positioning accuracy of the shift position.

[0116] In this embodiment, as described above, there is a predetermined amount of backlash S whereby driving force is not transmitted from the motor 10 to the detent plate 71, and the detent plate 71 is rotated while the rotational speed transmitted from the motor 10 is reduced.The detent plate 71 is further provided with a reduction mechanism 20, and is configured to detect that driving force is not transmitted from the motor 10 to the detent plate 71 due to the backlash S based on the output values ​​of the rotor rotation angle sensor 30 and the output shaft rotation angle sensor 40 and the design value DE, thereby detecting the bottom V of the valleys 81, 82, 83, and 84 of the end portions 81b and 84b, and reversing the movement of the detent spring 72 to obtain the rotation angle of the motor 10 corresponding to the bottom V of the multiple valleys 81, 82, 83, and 84. This allows the detent spring 72 to be held at the valley bottom V of the valley portions 81, 82, 83, and 84 of the detent plate 71 without moving the detent plate 71 in response to the drive of the motor 10 by an amount corresponding to a predetermined amount of backlash S (play) intentionally provided in the speed reduction mechanism 20. Therefore, it is possible to learn the valley bottom V positions of the valley portions 81, 82, 83, and 84 into which the positioning portion fits without applying an excessive load (external force) to the motor 10 side or the detent spring 72 side.

[0117] As described above, in this embodiment, the rotation angles of the motor 10 corresponding to the valley bottoms V of the plurality of valleys 81, 82, 83, and 84 are acquired by moving the detent spring 72 back and forth once between the end portions 81 b and 84 b on both sides of the plurality of valleys 81, 82, 83, and 84. This makes it possible to acquire (learn) the rotation angles of the motor 10 corresponding to the valley bottoms V of the plurality of valleys 81, 82, 83, and 84 simply by moving the detent spring 72 back and forth once between the end portions 81 b and 84 b on both sides of the plurality of valleys 81, 82, 83, and 84. Therefore, the tact time required to acquire the rotation angles of the motor 10 corresponding to the valley bottoms V of the plurality of valleys 81, 82, 83, and 84 can be shortened.

[0118] In this embodiment, as described above, when the detent spring 72 is moved to pass through the multiple valleys 81, 82, 83, and 84, based on the output values ​​of the rotor rotation angle sensor 30 and the output shaft rotation angle sensor 40 and the design value DE, if, after the motor 10 starts to drive, the same bottom V of the valley 80 as the bottom V of the valley 80 detected when the motor 10 started to drive is detected again in the same rotation direction as when the motor 10 started to drive, it is determined that the rotation angle of the motor 10 corresponding to the bottom V of the multiple valleys 81, 82, 83, and 84 has been obtained, and the drive of the motor 10 is stopped. This allows the driving of the motor 10 to be stopped if, after the motor 10 starts to drive, the same rotational direction as when the motor 10 started to drive and the same valley bottom V of the valley portion 80 as the valley bottom V of the valley portion 80 detected when the motor 10 started to drive is detected again, so that it can be reliably detected that the detent spring 72 has made one reciprocating movement between the end portions 81b, 84b on both sides of the multiple valley portions 81, 82, 83, 84.

[0119] In this embodiment, as described above, the multiple valleys 81, 82, 83, 84 include the parking position, reverse position, neutral position, and drive position as shift positions in this order from one end 81b to the other end 84b, and are configured to acquire the rotation angles of the motor 10 corresponding to the parking position, reverse position, neutral position, and drive position while the detent spring 72 is moved sequentially through the parking position, reverse position, neutral position, and drive position. This makes it possible to acquire (learn) the rotation angles of the motor 10 corresponding to the parking position, reverse position, neutral position, and drive position by reversing the movement of the detent spring 72 at the parking position and drive position located at the ends 81b, 84b.

[0120] As described above, in this embodiment, the detent plate 71 is configured to detect positions other than the four shift positions of the parking position, reverse position, neutral position, and drive position as an indeterminate shift position where the design value DE is not associated with the output value of the output shaft rotation angle sensor 40. This makes it possible to detect not only that the detent spring 72 is located in any of the parking position, reverse position, neutral position, and drive position, but also that the detent spring 72 is located in a position (indeterminate shift position) that does not correspond to any of the four shift positions of the parking position, reverse position, neutral position, and drive position. As a result, the position of the detent spring 72 can be detected more precisely, and the rotation angle of the motor 10 corresponding to the shift position can be acquired (learned) with greater accuracy.

[0121] In this embodiment, as described above, the valleys 81, 84 of the ends 81b, 84b are provided with the walls 81a, 84a that prevent the detent spring 72 from moving beyond the valleys 81, 84 of the ends 81b, 84b, and are configured to reverse the movement of the detent spring 72 so that the detent spring 72 does not collide with the walls 81a, 84a. This makes it possible to reverse the movement of the detent spring 72 so that the detent spring 72 does not collide with the walls 81a, 84a, thereby more reliably preventing the detent spring 72 from colliding with the walls 81a, 84a.

[0122] In this embodiment, as described above, the design value DE includes an angle map indicating the relationship between the shift position and the rotation angle of the detent plate 71 corresponding to the output value of the output shaft rotation angle sensor 40. This makes it possible to easily acquire (learn) the rotation angle of the motor 10 corresponding to the valley bottom V of the multiple valleys 81, 82, 83, and 84 based on the angle map indicating the relationship between the shift position and the rotation angle of the detent plate 71 corresponding to the output value of the output shaft rotation angle sensor 40.

[0123] (Variation) The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not by the description of the above embodiments, and includes all modifications (variations) within the meaning and scope of the claims.

[0124] For example, in the above embodiment, an example was shown in which the shift device has four shift positions, but the present invention is not limited to this. In the present invention, the shift device may have two, three, five or more shift positions.

[0125] In the above embodiment, the first and second estimated values ​​are calculated based on linear approximation, but the present invention is not limited to this. For example, the first and second estimated values ​​may be calculated by a method other than linear approximation (such as polynomial approximation).

[0126] In the above embodiment, an example was shown in which a predetermined amount of backlash S is provided in advance between the intermediate gear 21 and the intermediate gear 22 shown in Fig. 4, but the present invention is not limited to this. The present invention can be applied even when the predetermined amount of backlash S is not provided between the intermediate gear 21 and the intermediate gear 22 (when only unintended backlash occurs due to an assembly error or the like).

[0127] In addition, although the above embodiment shows an example in which the shift device is applied to a shift device for an automobile, 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.

[0128] In the above embodiment, the learning is completed by causing the detent spring to reciprocate once between both ends of the plurality of valleys, but the present invention is not limited to this. In the present invention, the learning may be completed after causing the detent spring to reciprocate multiple times between both ends of the plurality of valleys.

[0129] In the above embodiment, an example was shown in which a lever-type operating unit for switching shifts is provided on the vehicle, but the present invention is not limited to this. In the present invention, a button-type operating unit for switching shifts or the like may be provided on the vehicle. [Explanation of symbols]

[0130] 10 Motor 11 rotor 12 Stator 20 Reduction mechanism section 30 Rotor rotation angle sensor 40 Output shaft rotation angle sensor 71 Detent plate (shift switching member) 72 Detent spring (positioning member) 80, 81, 82, 83, 84 Valley 81b, 84b (of the multiple valleys) 100 Shifting Device 110 vehicles DE design value S backlash V valley bottom

Claims

1. A shift device mounted on a vehicle, a shift switching member including a plurality of valleys provided to correspond to the shift positions; a positioning member for establishing the shift position when fitted into any one of the plurality of recesses of the shift switching member; a motor including a rotor and a stator that drives the shift switching member; a rotor rotation angle sensor for detecting a rotation angle of the rotor; an output shaft rotation angle sensor that detects a rotation angle of the shift switching member; a storage unit that stores a design value obtained in advance, which associates the output value of the output shaft rotation angle sensor with the shift position, When the positioning member is moved to pass through the plurality of valleys, the current shift position is acquired at least when driving of the motor is started based on the output value of the output shaft rotation angle sensor and the design value stored in the storage unit, and the bottom of the valley at the end of the plurality of valleys is detected based on the output values ​​of the rotor rotation angle sensor and the output shaft rotation angle sensor and the design value stored in the storage unit, a shift device configured to reverse the movement of the positioning member at the bottom of the detected valley portion of the end portion, and, based on the output values ​​of the rotor rotation angle sensor and the output shaft rotation angle sensor and the design value, stop driving the motor when, after starting to drive the motor, a bottom of the same valley portion as the bottom of the valley portion detected at the start of driving the motor is detected again in the same rotation direction as when the motor started to drive.

2. a speed reduction mechanism that has a predetermined amount of backlash that prevents a driving force from being transmitted from the motor to the shift switching member and that rotates the shift switching member while reducing the rotational speed transmitted from the motor side; a state in which the output value of the output shaft rotation angle sensor is substantially constant due to the influence of the backlash while the output value of the rotor rotation angle sensor is fluctuating is detected as the bottom of the valley, and whether or not the detected bottom of the valley is the bottom of the valley at the end is determined based on the design value and the output value of the output shaft rotation angle sensor, 2. The shift device according to claim 1, wherein the shift device is configured to acquire a rotation angle of the motor corresponding to the bottoms of the plurality of valleys by reversing the movement of the positioning member when it is determined that the bottoms of the detected valleys are the bottoms of the valleys of the end portions.

3. 3. The shift device according to claim 1, wherein the positioning member is reciprocated once between the ends on both sides of the plurality of valley portions to obtain a rotation angle of the motor corresponding to the bottoms of the plurality of valley portions.

4. 4. The shift device according to claim 3, wherein when the positioning member is moved to pass through the plurality of valley portions, if, after starting to drive the motor, a valley bottom that is the same as the valley bottom detected at the start of driving of the motor is detected again in the same rotation direction as when the motor was started based on output values ​​of the rotor rotation angle sensor and the output shaft rotation angle sensor and the design value, it is determined that the rotation angle of the motor corresponding to the valley bottoms of the plurality of valley portions has been acquired, and driving of the motor is stopped.

5. the plurality of valleys include a parking position, a reverse position, a neutral position, and a drive position as the shift positions in the order of the parking position, the reverse position, the neutral position, and the drive position from one end to the other end, 5. The shift device according to claim 1, wherein the shift device is configured to acquire rotation angles of the motor corresponding to the parking position, the reverse position, the neutral position, and the drive position while the positioning member is moved in sequence so as to pass through the parking position, the reverse position, the neutral position, and the drive position.

6. 6. The shift device according to claim 5, wherein, in positions of the shift switching member other than the four shift positions of the parking position, the reverse position, the neutral position, and the drive position, the shift device is configured to detect that the shift switching member is in an indeterminate shift position where the design value is not associated with the output value of the output shaft rotation angle sensor.

7. A shift device mounted on a vehicle, a shift switching member including a plurality of valleys provided to correspond to the shift positions; a positioning member for establishing the shift position when fitted into any one of the plurality of recesses of the shift switching member; a motor including a rotor and a stator that drives the shift switching member; a rotor rotation angle sensor for detecting a rotation angle of the rotor; an output shaft rotation angle sensor that detects a rotation angle of the shift switching member; a storage unit that stores a design value obtained in advance, which associates the output value of the output shaft rotation angle sensor with the shift position, a shift device configured to acquire the current shift position at least when starting to drive the motor based on the output value of the output shaft rotation angle sensor and the design value stored in the memory unit when moving the positioning member to pass through the plurality of valleys, and to acquire the rotation angles of the motor corresponding to the bottoms of the plurality of valleys by moving the positioning member back and forth between the insides of the valleys at both ends of the plurality of valleys based on the output values ​​of the rotor rotation angle sensor and the output shaft rotation angle sensor and the design value stored in the memory unit.

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