Parking device for vehicle

Abstract

To provide a parking device for a vehicle which can suppress an increase in number of part items resulting from a rotation angle sensor for an output shaft.SOLUTION: A parking device 100 for a vehicle comprises a control part 8 for acquiring a gear rotation angle regulate position Φ1 on the basis of a rise in current value of a motor 5 which is generated by stop of the rotation of a driven gear 62 by a stopper 66 in a parking lock state. The control part 8 is constituted to perform control for acquiring a motor parking lock rotation angle position θ2 of the motor 5 on the basis of the acquired gear rotation angle regulate position Φ1 and a first relative rotation angle ΔΦ1, and acquiring a motor parking lock release rotation angle position θ3 of the motor 5 on the basis of the motor parking lock rotation angle position θ2 and a second relative rotation angle ΔΦ2.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a parking device for a vehicle. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a parking device for a vehicle is known (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a shift device (vehicle parking device) equipped with a motor. This shift device includes a driving force transmission mechanism (transmission mechanism), a detent spring, a detent plate, a parking mechanism (parking rod), a motor rotation angle sensor, an output shaft rotation angle sensor, and a control board (control unit).

[0004] The driving force transmission mechanism of the above-mentioned Patent Document 1 is configured to transmit driving force from a motor to a detent plate. The driving force transmission mechanism includes a gear portion (driven gear) and an output shaft. The gear portion is configured to rotate in accordance with the rotation of the motor. The output shaft is connected to the detent plate.

[0005] The detent plate in the above-mentioned Patent Document 1 includes a plurality of valleys corresponding to the parking position and non-parking positions including the reverse position, neutral position, and drive position as shift positions. The detent plate is configured to rotate between the parking position and the non-parking position by the driving force transmitted from the output shaft.

[0006] The parking mechanism in Patent Document 1 is connected to a detent plate. The parking mechanism is configured to drive the detent plate to a parking lock position where the rotation of the wheels is locked when the detent plate rotates to the parking position.

[0007] The control board in the above-mentioned Patent Document 1 performs control to acquire an output shaft parking lock rotational angle position of the output shaft corresponding to the parking lock position of the parking mechanism and an output shaft parking lock release rotational angle position of the output shaft corresponding to the parking lock release position of the parking mechanism, based on the motor rotational angle position acquired from the motor rotational angle sensor and the output shaft rotational angle position acquired from the output shaft rotational angle sensor.The control board controls the rotational angle position of the output shaft to each of the output shaft parking lock rotational angle position and the output shaft parking lock release rotational angle position, based on the acquired output shaft parking lock rotational angle position and output shaft parking lock release rotational angle position. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2021-196017 A Summary of the Invention [Problem to be solved by the invention]

[0009] However, in the shift device of Patent Document 1, the output shaft parking lock rotation angle position and the output shaft parking lock release rotation angle position cannot be obtained without information on both the motor rotation angle position obtained from the motor rotation angle sensor and the output shaft rotation angle position obtained from the output shaft rotation angle sensor. Therefore, in the shift device of Patent Document 1, it is desired to obtain each of the output shaft parking lock rotation angle position and the output shaft parking lock release rotation angle position without using the output shaft rotation angle sensor, thereby suppressing an increase in the number of parts of the device (parking device) caused by the output shaft rotation angle sensor.

[0010] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a parking device for a vehicle that is capable of suppressing an increase in the number of parts caused by an output shaft rotation angle sensor. [Means for solving the problem]

[0011] In order to achieve the above object, a vehicle parking device in one aspect of the present invention includes a motor that generates a driving force for switching between a parking lock state and a parking lock release state of the vehicle, a driven gear that rotates with the rotation of the motor, and a stopper that stops rotation of the driven gear at a gear rotation angle restriction position in the parking lock state, the drive mechanism being connected to the motor and configured to increase a reduction ratio from the gear rotation angle restriction position toward a gear parking lock rotation angle position of the driven gear, a parking rod that is connected to the transmission mechanism and reciprocates between the parking lock position in the parking lock state and the parking lock release position in the parking lock release state, and and a gear parking lock rotation angle position of the driven gear, and a control unit that acquires a gear rotation angle restriction position based on an increase in the motor current value that occurs when the rotation of the driven gear is stopped by the stopper in a parking lock state, and the control unit is configured to perform control to acquire a motor parking lock rotation angle position of the motor based on the acquired gear rotation angle restriction position and the first relative rotation angle, and to acquire a motor parking lock rotation angle position of the motor based on the motor parking lock rotation angle position and the second relative rotation angle.

[0012] In one aspect of the present invention, a vehicle parking device includes a storage unit that stores the first relative rotation angle and the second relative rotation angle, as described above. The vehicle parking device includes a control unit that performs control to acquire a motor parking lock rotation angle position of the motor based on the acquired gear rotation angle restriction position and the first relative rotation angle, and to acquire a motor parking lock release rotation angle position of the motor based on the motor parking lock rotation angle position and the second relative rotation angle. As a result, the gear rotation angle restriction position is acquired based on an increase in the current value of the motor, and the first relative rotation angle is stored in the storage unit, so that the motor parking lock rotation angle position can be acquired without using an output shaft rotation angle sensor. Also, the motor parking lock release rotation angle position is acquired based on the acquired motor parking lock rotation angle position and the first relative rotation angle stored in the storage unit, so that the motor parking lock release rotation angle position can be acquired without using an output shaft rotation angle sensor. As a result, the output shaft parking lock rotation angle position and the output shaft parking lock release rotation angle position can be acquired without using an output shaft rotation angle sensor, so that an increase in the number of parts due to the output shaft rotation angle sensor can be suppressed. Also, if the first relative rotation angle and the second relative rotation angle are stored in the storage unit, the output shaft parking lock rotation angle position and the output shaft parking lock release rotation angle position can be acquired, so that even if the output shaft parking lock rotation angle position and the output shaft parking lock release rotation angle position are erased when the vehicle power is turned off, the output shaft parking lock rotation angle position and the output shaft parking lock release rotation angle position can be acquired when the vehicle power is turned on. As a result, a dedicated backup power supply and a dedicated circuit for the backup power supply for storing the output shaft parking lock rotation angle position and the output shaft parking lock release rotation angle position after the vehicle power is turned off are not required, so that an increase in the number of parts can be suppressed.

[0013] In the vehicle parking device according to the above-mentioned aspect, the transmission mechanism preferably includes a reduction mechanism having a driven gear and configured so that the degree of increase in the reduction ratio from the gear rotation angle restriction position to the gear parking lock rotation angle position is greater than the degree of change in the reduction ratio in the intermediate portion between the gear parking lock rotation angle position and the gear parking lock release rotation angle position.

[0014] With this configuration, the degree of increase in the reduction ratio from the gear rotation angle restriction position to the gear parking lock rotation angle position can be increased, thereby reducing the drive amount of the output end of the reduction mechanism due to the rotation of the motor from the gear rotation angle restriction position to the gear parking lock rotation angle position. This reduces the drive amount of the output end of the reduction mechanism caused by the rotation of the driven gear until it is stopped by the stopper at the acquisition of the gear rotation angle restriction position, making it possible to prevent the parking rod from moving unintentionally from the parking position.

[0015] In this case, preferably, the transmission mechanism further includes an output shaft for outputting the torque of the motor to the parking rod, and the difference between the motor rotational angle restriction position of the motor corresponding to the gear rotational angle restriction position and the motor parking lock rotational angle position is greater than the difference between the output shaft rotational angle restriction position of the output shaft corresponding to the gear rotational angle restriction position and the output shaft parking lock rotational angle position of the output shaft corresponding to the gear parking lock rotational angle position due to an increase in the reduction ratio by the reduction mechanism.

[0016] Here, if the difference between the motor rotation angle restriction position and the motor parking lock rotation angle position is reduced in accordance with the difference between the output shaft rotation angle restriction position and the output shaft parking lock rotation angle position, it is possible that the motor rotation angle restriction position and the motor parking lock rotation angle position may be erroneously detected due to a detection error of the sensor. Therefore, by utilizing an increase in the reduction ratio by the reduction mechanism to increase the difference between the motor rotation angle restriction position and the motor parking lock rotation angle position compared to the difference between the output shaft rotation angle restriction position and the output shaft parking lock rotation angle position, it is possible to suppress erroneous detection of the motor rotation angle restriction position and the motor parking lock rotation angle position due to a detection error of the sensor. In addition, by making the difference between the output shaft rotation angle restriction position and the output shaft parking lock rotation angle position relatively small, the amount of rotation of the output shaft caused by the rotation of the motor can be reduced, so that it is possible to prevent the parking rod from moving unintentionally from the parking position.

[0017] In the vehicle parking device according to the above aspect, the control unit is preferably configured to perform control to obtain the motor parking lock release rotational angle position based on rotating the driven gear by the second relative rotation angle from the motor parking lock rotational angle position when switching from the parking lock state to the parking lock release state.

[0018] With this configuration, since a process of rotating the driven gear to the gear parking lock release rotation angle position is necessary when switching from the parking lock state to the parking lock release state, the motor parking lock release rotation angle position can be obtained by utilizing this process. As a result, unlike a case where a dedicated process for obtaining the motor parking lock release rotation angle position is provided to rotate the driven gear, the process of obtaining the motor parking lock release rotation angle position can be performed efficiently.

[0019] In the vehicle parking device according to the above aspect, the following configuration is also possible.

[0020] (Additional note 1) In a vehicle parking device equipped with a transmission mechanism including the above-mentioned output shaft, the difference between the motor parking lock release rotational angle position and the motor parking lock rotational angle position of the motor is greater than or equal to the difference between the motor rotational angle restriction position and the motor parking lock rotational angle position.

[0021] Here, even if the difference between the motor parking lock release rotational angle position and the motor parking lock rotational angle position is made small, it is possible that the motor parking lock release rotational angle position and the motor parking lock rotational angle position will be erroneously detected due to a detection error of the sensor. Therefore, by making the difference between the motor parking lock release rotational angle position and the motor parking lock rotational angle position of the motor larger compared to the difference between the output shaft rotational angle restriction position and the output shaft parking lock rotational angle position, it is possible to suppress erroneous detection of the motor parking lock release rotational angle position and the motor parking lock rotational angle position due to a detection error of the sensor.

[0022] (Additional note 2) In the vehicle parking device according to the above aspect, the control unit is configured to, when the driven gear is rotated in accordance with the gear rotation angle restriction position in a parking lock state, if the motor current value does not increase, rotate the driven gear again toward the gear rotation angle restriction position and determine whether or not the initial position is the parking lock release position based on the motor current value when the driven gear is rotated again.

[0023] With this configuration, if the motor current value does not increase when the motor is rotated again and it is determined that the initial position is the parking lock release position, the driven gear can be rotated further by the first relative rotation angle toward the gear rotation angle restriction position, thereby preventing the transmission mechanism and motor from being subjected to excessive load due to the driven gear rotating more than necessary and coming into strong contact with the stopper.

[0024] (Additional note 3) In the parking device in which the control unit performs control to obtain the motor parking lock release rotation angle position based on rotating the driven gear by the second relative rotation angle, the control unit is configured to, when switching from a parking lock state to a parking lock release state, control to first align the motor rotation angle with the motor parking lock rotation angle position, and then store the motor rotation angle position in the memory unit as the motor parking lock release rotation angle position based on rotating the driven gear by the second relative rotation angle.

[0025] With this configuration, the motor parking lock release rotation angle position can be obtained after aligning with the motor parking lock rotation angle position, so that the motor parking lock release rotation angle position to be stored in the memory unit can be obtained with high accuracy.

[0026] (Additional note 4) In this case, the transmission mechanism further includes an output shaft for outputting the torque of the motor to the parking rod, and the control unit is configured to control the output shaft to align with the output shaft parking lock rotation angle position based on rotating the driven gear by the second relative rotation angle after aligning it with the stored motor parking lock release rotation angle position when switching from the parking lock release state to the parking lock state.

[0027] With this configuration, by aligning the output shaft with the output shaft parking lock rotation angle position, the parking rod can be moved to the parking position in the parking lock state, so that the vehicle can be stopped with its movement reliably stopped.

[0028] (Additional note 5) In a parking device equipped with a transmission mechanism including the above-mentioned reduction mechanism, the driven gear is configured to rotate about a central axis of rotation by a driving force from a motor, and the reduction mechanism has a link member connected to the driven gear and having a driving side end that rotates with the rotation of the driven gear and an output side end that is the other end that rotates with the rotation of the driving side end, and the central axis of rotation of the driven gear, the driving side end of the link member, and the output side end of the link member are aligned in a straight line when viewed from one side in the direction in which the central axis of rotation of the driven gear extends, in both the parking lock state and the parking lock release state.

[0029] Here, the link member, whose drive side end and output side end are aligned in a straight line with respect to the rotation center axis of the driven gear, is in a state of a consideration point where torque is not transmitted, so that the reduction ratio of the reduction mechanism is increased so as not to transmit torque due to the consideration point in both the parking lock state and the parking lock release state. This makes it possible to easily realize a structure of the reduction mechanism that greatly increases the reduction ratio from the gear rotation angle restriction position to the gear parking lock rotation angle position using the link member. Effect of the Invention

[0030] According to the present invention, as described above, it is possible to suppress an increase in the number of parts caused by the output shaft rotation angle sensor. [Brief description of the drawings]

[0031] [Figure 1] 1 is a front view showing a parking lock release state of a parking device for a vehicle according to an embodiment of the present invention; [Diagram 2] 1 is a front view showing a parking lock state of a parking device for a vehicle according to an embodiment of the present invention; [Diagram 3] 5 is a graph showing a change in the reduction ratio of a transmission mechanism when a driven gear of the vehicle parking device of the embodiment rotates. [Figure 4]4 is a graph showing the relationship between the rotational angle position of a driven gear, the rotational angle position of a motor, and the rotational angle position of an output shaft of the vehicle parking device of the embodiment. [Diagram 5] 1 is a front view showing a state in which a driven gear is rotated toward a gear rotation angle restriction position in a parking lock state of the vehicle parking device of the embodiment. FIG. [Figure 6] 1 is a front view showing a state in which a driven gear is rotated toward a gear parking lock rotation angle position in a parking lock state of the vehicle parking device of the embodiment. FIG. [Figure 7] FIG. 13 shows a graph showing the change in the reduction ratio of the transmission mechanism when the driven gear of the comparative example vehicle parking device rotates, and a graph showing the relationship between the rotational angle position of the driven gear of the comparative example vehicle parking device and each of the rotational angle positions of the motor and the output shaft. [Figure 8] 1 is a diagram showing a first initial position in a graph showing the relationship between the rotational angular position of a driven gear, the rotational angular position of a motor, and the rotational angular position of an output shaft of the vehicle parking device according to the embodiment. FIG. [Figure 9] 13 is a diagram showing a second initial position in a graph showing the relationship between the rotational angular position of the driven gear, the rotational angular position of the motor, and the rotational angular position of the output shaft of the vehicle parking device of the embodiment. FIG. [Figure 10] 10 is a front view showing a state in which the driven gear is rotated by a second relative rotation angle when switching from a parking lock state to a parking lock release state in the vehicle parking device of the embodiment. FIG. [Figure 11] 10 is a front view showing a state in which the driven gear is rotated by a second relative rotation angle when switching from a parking lock release state to a parking lock state in the vehicle parking device of the embodiment. FIG. [Figure 12] 4 is a flowchart showing a method for acquiring a rotation angle position of a motor parking lock of the vehicle parking device according to the embodiment. [Figure 13]4 is a flowchart showing a method for acquiring a motor parking lock release rotation angle position of the vehicle parking device according to the embodiment. [Figure 14] 4 is a flowchart showing a parking lock state switching method of the vehicle parking device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0033] The configuration of a vehicle parking device 100 according to this embodiment will be described with reference to FIGS. 1 to 14.

[0034] As shown in Fig. 1, a vehicle parking device 100 is mounted on a vehicle. In the vehicle, when a driver performs a shift switching operation via a parking switch, an electrical shift switching control is performed.

[0035] That is, when the driver operates the parking switch, a signal for switching the shift position is input to the vehicle parking device 100 via a sensor provided in the parking switch. Based on the signal input from the parking switch, the vehicle parking device 100 is switched to a parking lock position P2 (see FIG. 2) corresponding to the driver's switching operation, or to a parking lock release position P1. This allows the vehicle parking device 100 to switch between locking and unlocking the rotation of the wheels.

[0036] The above-described shift switching control is called "shift-by-wire." A vehicle in which such a shift switching control is performed is, for example, an electric vehicle that is equipped with only a motor as a power source.

[0037] The vehicle parking device 100 has a structure capable of switching between locking and unlocking the rotation of the wheels. The vehicle parking device 100 includes a parking gear 1, a parking pole 2, a parking rod 3, a guide unit 4, a motor 5, a transmission mechanism 6, a motor rotation angle sensor 7, a control unit 8, and a case 9.

[0038] The direction in which the rotation center axis Cm of the motor 5 extends is the Z direction, one side of the Z direction is the Z1 direction, and the other side of the Z direction is the Z2 direction. The direction in which the motor 5 and the parking gear 1 are lined up is the X direction, the motor 5 side of the X direction is the X1 direction, and the parking gear 1 side of the X direction is the X2 direction. The direction in which the parking gear 1 and the parking pole 2 are lined up is the Y direction, the park pole 2 side of the Y direction is the Y1 direction, and the parking gear 1 side of the Y direction is the Y2 direction. The X direction and the Y direction are perpendicular to each other. The Z direction is perpendicular to the X direction and the Y direction.

[0039] The parking gear 1 is fixed to the wheel. The parking gear 1 rotates integrally with the wheel. The parking gear 1 is configured so that the teeth 1a of the parking gear 1 can be engaged with the locking claws 2a of the parking pole 2.

[0040] The park pole 2 rotates towards the parking gear 1 and is guided to a position (locked position) where the locking claw 2a meshes with the teeth 1a of the parking gear 1. The park pole 2 stops the rotation of the parking gear 1 by guiding the locking claw 2a to the locked position. In this way, the parking pole 2 is put into a parking lock state (see FIG. 2) by guiding the locking claw 2a of the park pole 2 to the locked position.

[0041] The parking pole 2 also rotates in a direction away from the teeth 1a of the parking gear 1 and is guided to a position (unlocked position) where the engagement between the locking claw 2a and the teeth 1a of the parking gear 1 is released. The locking claw 2a of the parking pole 2 is guided to the unlocked position, thereby enabling the rotation of the parking gear 1. In this way, the parking pole 2 is guided to the unlocked position, resulting in a parking lock released state (see FIG. 1).

[0042] The parking rod 3 is configured to move along both the X1 direction and the X2 direction. The parking rod 3 is configured to move to a parking lock release position P1 in the parking lock release state by moving in the X1 direction. The parking rod 3 is configured to move to a parking lock position P2 in the parking lock state by moving in the X2 direction. That is, the parking rod 3 is configured to reciprocate between the parking lock position P2 and the parking lock release position P1. The parking rod 3 is connected to the transmission mechanism 6, and thus moves linearly by the driving force transmitted from the motor 5 via the transmission mechanism 6.

[0043] The parking rod 3 includes a rod portion 31, a cam portion 32, a retraction spring 33, and a support portion .

[0044] The rod portion 31 is a bar-shaped member extending along the X direction.

[0045] The cam portion 32 is fixed to the tip of the rod portion 31. The cam portion 32 is configured to reciprocate in a direction approaching (X2 direction) and a direction away (X1 direction) from the park pole 2 together with the reciprocating movement of the parking rod 3. Here, as the cam portion 32 moves in a direction approaching the park pole 2, the cam surface of the cam portion 32 rotates the park pole 2 so that the locking claw 2a reaches the locked position. As the cam portion 32 moves in a direction away from the park pole 2, the cam surface of the cam portion 32 rotates the park pole 2 so that the locking claw 2a reaches the unlocked position.

[0046] The retraction spring 33 is, for example, a coil spring. One end of the retraction spring 33 on the X2 direction side abuts against the X1 direction side of the cam portion 32 on the rod portion 31. The other end of the retraction spring 33 on the X1 direction side abuts against the X2 direction side of the support portion 34 on the rod portion 31, and is supported by the support portion 34. As a result, the retraction spring 33 is configured to press the cam portion 32 against the guide portion 4. The guide portion 4 is configured to guide the cam portion 32 moving in the X2 direction toward the Y2 direction side (toward the park pole 2). The guide portion 4 faces the park pole 2 in the Y direction.

[0047] The motor 5 is configured to generate a driving force for switching the vehicle between a parking lock state and a parking lock release state. The motor 5 is a three-phase motor of a surface permanent magnet type (SPM (Surface Permanent Magnet Motor)) incorporating a permanent magnet. The motor 5 is housed inside the case 9 in a fixed position.

[0048] Specifically, the motor 5 includes a stator 51, a rotor 52, and a motor shaft 53. The stator 51 has a stator core and a multi-phase (U-phase, V-phase, and W-phase) excitation coil that generates a magnetic force when energized. The rotor 52 is rotated about a rotation center axis Cm extending in the Z direction. The motor shaft 53 is connected to the rotor 52. The motor shaft 53 is rotated together with the rotor 52 about the rotation center axis Cm extending in the Z direction.

[0049] (Transmission mechanism) 1, the transmission mechanism 6 is configured to transmit the driving force of the motor 5 to the parking rod 3. The input side of the transmission mechanism 6 is connected to the motor 5. The output side of the transmission mechanism 6 is connected to the parking rod 3.

[0050] Specifically, the transmission mechanism 6 includes a drive gear 61 , a driven gear 62 , a rotating shaft 63 , a link member 64 , a connecting member 65 , and a stopper 66 .

[0051] The driving gear 61 is configured to rotate about a central axis of rotation Cm extending in the Z direction integrally with the motor shaft 53 by the driving force from the motor 5. The driving gear 61 is in mesh with a driven gear 62.

[0052] The driven gear 62 is configured to rotate around the rotation center axis Cg by the driving force from the motor 5. The driven gear 62 is a sector gear (fan-shaped gear) having multiple external teeth on a part of its outer periphery attached to the rotating shaft 63. The multiple external teeth of the driven gear 62 mesh with the external teeth of the driving gear 61. The number of teeth of the driven gear 62 is greater than the number of teeth of the driving gear 61. As a result, the rotation speed of the driving gear 61 is reduced in the driven gear 62.

[0053] The rotating shaft 63 is disposed on a rotation center axis Cg of the driven gear 62. The rotating shaft 63 extends in the Z direction. The driven gear 62 is attached to the rotating shaft 63 so as to be rotatable integrally therewith.

[0054] The link member 64 connects the driven gear 62 and the connecting member 65. The link member 64 is capable of transmitting torque from the driven gear 62 to the connecting member 65, and is also capable of transmitting torque from the connecting member 65 to the driven gear 62.

[0055] The link member 64 has a link main body portion 64a, a driving side pin 64b, an output side pin 64c, and a recess portion 64d.

[0056] The link main body 64a is a plate-like member that is J-shaped when viewed from the Z1 direction side.

[0057] The driving side pin 64b connects the driving side (input side) of the link main body 64a to the driven gear 62. The driving side pin 64b is connected to the driving side end E1 of the link main body 64a. The output side pin 64c connects the output side of the link main body 64a to the connecting member 65. The output side pin 64c is connected to the output side end E2 of the link main body 64a. The relief portion 64d is curved to avoid interference with the rotating shaft 63.

[0058] The connecting member 65 connects the link member 64 and the parking rod 3. The connecting member 65 has a first link 65a, a second link 65b, an output shaft 65c, and a rod side pin 65d.

[0059] The first link 65a is a plate-like member that connects the link member 64 and the second link 65b. One end of the first link 65a on the Y2 direction side is connected to the link member 64 by the output side pin 64c. The other end of the first link 65a on the Y1 direction side is connected to the second link 65b by the output shaft 65c. The second link 65b is a plate-like member that connects the first link 65a and the parking rod 3. One end of the second link 65b on the Y1 direction side is connected to the parking rod 3 by the rod side pin 65d. The output shaft 65c is configured to output the torque transmitted from the motor 5 via the drive gear 61, the driven gear 62, and the link member 64 to the second link 65b connected to the parking rod 3. The output shaft 65c is a spline shaft extending along the Z direction for rotating the first link 65a and the second link 65b by the torque from the motor 5. The output shaft 65c rotates about a rotation center axis Cr that extends along the Z direction.

[0060] <Stopper> The stopper 66 is configured to stop further rotation of the driven gear 62 when the parking lock is released. The stopper 66 is also configured to stop further rotation of the driven gear 62 when the parking lock is released. Specifically, the stopper 66 has an engagement pin 66a and a slit 66b. The engagement pin 66a extends from the case 9 in the Z1 direction. The engagement pin 66a is slidably inserted into the slit 66b. The slit 66b is formed penetrating the driven gear 62 in the Z2 direction. The slit 66b is formed in an arc shape along the circumferential direction around the rotation center axis Cg of the driven gear 62.

[0061] Here, in the parking lock state, the inner surface of the end portion on the X1 direction side (one side) of the arc-shaped slit 66b arranged on the Y1 direction side engages with the engagement pin 66a. In the parking lock released state, the inner surface of the end portion on the X1 direction side (the other side) of the arc-shaped slit 66b arranged on the Y2 direction side engages with the engagement pin 66a. As a result, the stopper 66 restricts further rotation of the driven gear 62 in both the parking lock state and the parking lock released state.

[0062] <Considerations for transmission mechanism> The vehicle parking device 100 is configured so that the link member 64 is in a thinking point state in both the parking lock state and the parking lock release state. Here, the link member 64 being in a thinking point state refers to the link member 64 being in a state in which no torque for moving the link member 64 is generated (the link member 64 does not move).

[0063] Specifically, the rotation center axis Cg of the driven gear 62, the drive side end E1 of the link member 64, and the output side end E2 of the link member 64 are aligned in a straight line when viewed from the Z1 direction side (one side in the direction in which the rotation center axis Cg of the driven gear 62 extends) in both the parking lock state and the parking lock release state.

[0064] 1, in the parking lock release state, the rotation center axis Cg of the driven gear 62, the drive side end E1 of the link member 64 arranged on the output side end E2 side with respect to the rotation center axis Cg of the driven gear 62, and the output side end E2 of the link member 64 are aligned in a straight line when viewed from the Z1 direction. Specifically, the rotation center axis Cg of the rotation shaft 63 of the driven gear 62 is positioned on a straight line connecting the center point of the drive side pin 64b of the link member 64 and the center point of the drive side pin 64b of the link member 64, so that the link member 64 becomes the first pivot point.

[0065] 2, in the parking lock state, the rotation center axis Cg of the driven gear 62, the drive side end E1 of the link member 64 arranged on the opposite side of the rotation center axis Cg of the driven gear 62 from the output side end E2, and the output side end E2 of the link member 64 are aligned in a straight line when viewed from the Z1 direction. Specifically, the rotation center axis Cg of the rotation shaft 63 of the driven gear 62 is arranged on a straight line connecting the center point of the drive side pin 64b of the link member 64 and the center point of the drive side pin 64b of the link member 64, so that the link member 64 becomes the second pivot point.

[0066] <Reduction ratio> The transmission mechanism 6 functions as a reduction mechanism that increases the torque of the motor 5 and transmits it to the parking rod 3 via the output shaft 65c. That is, the reduction ratio of the transmission mechanism 6 changes as shown in Fig. 3. In Fig. 3, the reduction ratio of the transmission mechanism 6 is shown corresponding to the change in the rotation angle of the driven gear 62.

[0067] The reduction ratio of the transmission mechanism 6 increases from the gear rotation angle restriction position Φ1 toward the gear parking lock rotation angle position Φ2 of the driven gear 62. Specifically, the increase rate Up1 of the reduction ratio from the gear rotation angle restriction position Φ1 to the gear parking lock rotation angle position Φ2 is greater than the increase rate Mup1 of the reduction ratio of the intermediate portion Mid between the gear parking lock rotation angle position Φ2 and the gear parking lock release rotation angle position Φ3 of the driven gear 62. The intermediate portion Mid is, for example, a rotation angle range including a central rotation angle that is in the middle between the gear parking lock rotation angle position Φ2 and the gear parking lock release rotation angle position Φ3. The increase rate Up1 is an example of the "degree of increase of the reduction ratio" in the claims. The increase rate Mup1 is also an example of the "degree of change in the intermediate portion" in the claims.

[0068] Here, the gear rotation angle restriction position Φ1 is a rotation angle position of the driven gear 62 where the rotation of the driven gear 62 is restricted by the stopper 66 in the parking lock state. The gear parking lock rotation angle position Φ2 is a rotation angle position of the driven gear 62 when the parking rod 3 moves to the parking lock position P2. The gear parking lock release rotation angle position Φ3 is a rotation angle position of the driven gear 62 when the parking rod 3 moves to the parking lock release position P1.

[0069] Moreover, the reduction gear ratio of the transmission mechanism 6 increases from the gear parking lock release rotational angle position Φ3 of the driven gear 62 toward the first gear consideration point rotational angle position Φ4. Specifically, the increase rate Up2 of the reduction gear ratio from the gear parking lock release rotational angle position Φ3 to the first gear consideration point rotational angle position Φ4 is greater than the increase rate Mup2 of the reduction gear ratio in the intermediate portion Mid between the gear parking lock rotational angle position Φ2 and the gear parking lock release rotational angle position Φ3. The increase rate Mup2 is an example of the "degree of change in the intermediate portion" in the claims.

[0070] Here, the first gear consideration point rotation angle position Φ4 is the rotation angle position of the driven gear 62 at the first consideration point in the parking lock release state. The second gear consideration point rotation angle position Φ5 is the rotation angle position of the driven gear 62 at the second consideration point in the parking lock state. Also, the gear rotation angle restriction position Φ6 is the rotation angle position of the driven gear 62 at which the rotation of the driven gear 62 is restricted by the stopper 66 in the parking lock release state.

[0071] In addition, the reduction ratio of the transmission mechanism 6 decreases from the maximum reduction ratio toward the minimum reduction ratio and increases from the minimum reduction ratio to the maximum reduction ratio between the first gear consideration point rotational angle position Φ4 and the second gear consideration point rotational angle position Φ5.

[0072] (Motor rotation angle sensor) 2, the motor rotation angle sensor 7 is a sensor that detects the rotation angle position of the motor shaft 53 of the motor 5. The motor rotation angle sensor 7 is disposed at a position facing the motor shaft 53 in the Z1 direction. The motor rotation angle sensor 7 is formed of, for example, a resolver.

[0073] The motor rotation angle sensor 7 improves the resolution for detecting the rotation angle position of the motor 5 by applying the resolution for 360-degree rotation of the motor 5 to rotation of the motor 5 up to a predetermined rotation angle (for example, 90 degrees). Furthermore, the motor rotation angle sensor 7 is configured to reset the rotation angle position of the motor 5 to an initial value when the rotation angle position of the motor 5 exceeds the predetermined rotation angle. For this reason, the motor rotation angle sensor 7 is configured to detect the rotation angle position of the motor 5 in a range equal to or greater than 0 degrees and equal to or less than the predetermined rotation angle.

[0074] (Control unit) The control unit 8 includes a CPU (Central Processing Unit) and a storage unit 81 including a non-volatile storage unit and a volatile storage unit. The control unit 8 is an ECU (Electronic Control Unit). The storage unit 81 stores a rotation angle position control program for acquiring and controlling the rotation angle position of the output shaft 65c.

[0075] As shown in Fig. 4, the non-volatile storage unit stores a first relative rotation angle ΔΦ1, a second relative rotation angle ΔΦ2, and a third relative rotation angle ΔΦ3. The first relative rotation angle ΔΦ1 is an angle indicating the difference between a gear rotation angle restriction position Φ1 and a gear parking lock rotation angle position Φ2, both measured in advance (ΔΦ1 = Φ2 - Φ1). The second relative rotation angle ΔΦ2 is an angle indicating the difference between a gear parking lock rotation angle position Φ2 and a gear parking lock release rotation angle position Φ3, both measured in advance (ΔΦ2 = Φ3 - Φ2). The third relative rotation angle ΔΦ3 is an angle obtained by further subtracting the first relative rotation angle ΔΦ1 from the difference between the gear parking lock rotation angle position Φ2 and the gear parking lock release rotation angle position Φ3, both measured in advance (ΔΦ3 = Φ3 - Φ2 - ΔΦ1). Each of the first relative rotation angle ΔΦ1, the second relative rotation angle ΔΦ2, and the third relative rotation angle ΔΦ3 is a design value of the vehicle parking device 100 at the time of shipment from the factory.

[0076] (Rotation angle position control program) The rotation angle position control program will be described in detail below with reference to FIGS.

[0077] The control unit 8 of this embodiment performs control to obtain the motor rotation angle restriction position θ1, the motor parking lock rotation angle position θ2, and the motor parking lock release rotation angle position θ3 based on the gear rotation angle restriction position Φ1, the first relative rotation angle ΔΦ1, the second relative rotation angle ΔΦ2, and the third relative rotation angle ΔΦ3.

[0078] The motor rotation angle restriction position θ1, the motor parking lock rotation angle position θ2, and the motor parking lock release rotation angle position θ3 are each acquired by the control unit 8 based on a detection signal acquired from the motor rotation angle sensor 7.

[0079] Here, as shown in Fig. 4, the rotational angle position of the motor 5 and the rotational angle position of the output shaft 65c correspond to each other via the rotational angle position of the driven gear 62. In Fig. 4, this mutual correspondence is shown by a horizontal axis showing the rotational angle position of the driven gear 62, one vertical axis showing the rotational angle position of the motor 5, and the other vertical axis showing the rotational angle position of the output shaft 65c.

[0080] Therefore, the above-mentioned gear rotation angle restriction position Φ1, gear parking lock rotation angle position Φ2, and gear parking lock release rotation angle position Φ3 correspond to the motor rotation angle restriction position θ1, motor parking lock rotation angle position θ2, and motor parking lock release rotation angle position θ3, respectively.

[0081] In addition, the gear rotation angle restriction position Φ1, the gear parking lock rotation angle position Φ2, and the gear parking lock release rotation angle position Φ3 correspond to the output shaft rotation angle restriction position Ψ1, the output shaft parking lock rotation angle position Ψ2, and the output shaft parking lock release rotation angle position Ψ3, respectively.

[0082] As a result, the motor rotation angle restriction position θ1 and the output shaft rotation angle restriction position Ψ1 correspond to each other via the gear rotation angle restriction position Φ1. The motor parking lock rotation angle position θ2 and the output shaft parking lock rotation angle position Ψ2 correspond to each other via the gear parking lock rotation angle position Φ2. The motor parking lock release rotation angle position θ3 and the output shaft parking lock release rotation angle position Ψ3 correspond to each other via the gear parking lock release rotation angle position Φ3.

[0083] Therefore, by obtaining the motor rotational angle restriction position θ1, the motor parking lock rotational angle position θ2, and the motor parking lock release rotational angle position θ3, the output shaft rotational angle restriction position Ψ1, the output shaft parking lock rotational angle position Ψ2, and the output shaft parking lock release rotational angle position Ψ3 are each obtained.

[0084] The motor parking lock rotational angle position θ2 and the motor parking lock release rotational angle position θ3 are stored in the volatile storage unit 81. The motor rotational angle restriction position θ1, the gear rotational angle restriction position Φ1, the gear parking lock rotational angle position Φ2, the gear parking lock release rotational angle position Φ3, the output shaft rotational angle restriction position Ψ1, the output shaft parking lock rotational angle position Ψ2, and the output shaft parking lock release rotational angle position Ψ3 are not stored in the storage unit 81.

[0085] For this reason, the control unit 8 performs rotation angle position control of the output shaft 65c to each of the output shaft parking lock rotation angle position Ψ2 and the output shaft parking lock release rotation angle position Ψ3, based on the motor parking lock rotation angle position θ2 and the motor parking lock release rotation angle position θ3 stored in the volatile memory unit and the first relative rotation angle ΔΦ1 and the second relative rotation angle ΔΦ2 stored in the non-volatile memory unit.

[0086] In addition, since the motor parking lock rotation angle position θ2 and the motor parking lock release rotation angle position θ3 are stored in the volatile storage unit, they are erased when the power supply of the vehicle is turned off. As a result, the motor parking lock rotation angle position θ2 and the motor parking lock release rotation angle position θ3 are acquired and stored in the volatile storage unit every time the power supply of the vehicle is turned on. However, the vehicle parking device 100 is not provided with a backup power supply and a backup power supply circuit for storing each of the motor parking lock rotation angle position θ2 and the motor parking lock release rotation angle position θ3. In addition, the rotation angle position control program does not incorporate a process for reacquiring (restoring) each of the motor parking lock rotation angle position θ2 and the motor parking lock release rotation angle position θ3, which is performed when the connection to the backup power supply is lost.

[0087] Next, we will explain in order the acquisition of the motor parking lock rotational angle position θ2 when the power is turned on, the acquisition of the motor parking lock release rotational angle position θ3 when switching from the parking lock state to the parking lock release state, and the control when switching from the parking lock release state to the parking lock state.

[0088] (Getting the motor parking lock rotation angle position) 5, when the vehicle power supply is turned on, the control unit 8 performs control to rotate the driven gear 62 in the Rlk direction by the first relative rotation angle ΔΦ1 in order to confirm the initial rotational angle position of the output shaft 65c. By rotating the driven gear 62 in the Rlk direction, the control unit 8 performs control to determine whether the current value of the motor 5 has increased.

[0089] That is, in the parking lock state, the control unit 8 performs control to determine whether or not the initial position of the rotational angle position of the output shaft 65c when the vehicle power is ON is the output shaft parking lock rotational angle position Ψ2, based on an increase in the current value of the motor 5 caused by the rotation of the driven gear 62 being stopped by the stopper 66. Also, in the parking lock state, the control unit 8 performs control to obtain the gear rotation angle restriction position Φ1, based on an increase in the current value of the motor 5 caused by the rotation of the driven gear 62 being stopped by the stopper 66.

[0090] When the vehicle power supply is ON, if the rotation angle position of the output shaft 65c is the output shaft parking lock rotation angle position Ψ2, the rotation of the driven gear 62 is stopped by the stopper 66 by rotating the driven gear 62 by the first relative rotation angle Φ1 in the Rlk direction (see FIG. 4), and the current value of the motor 5 increases. As a result, the control unit 8 determines that the initial position of the rotation angle position of the output shaft 65c when the vehicle power supply is ON is the output shaft parking lock rotation angle position Ψ2. In addition, the control unit 8 determines that the rotation angle position of the driven gear 62 corresponding to the rotation angle position of the motor 5 (motor rotation angle restriction position θ1) detected by the motor rotation angle sensor 7 when the current value increases is the gear rotation angle restriction position Φ1. As a result, the gear rotation angle restriction position Φ1 is acquired.

[0091] As shown in FIG. 6, the control unit 8 performs control to acquire the motor parking lock rotation angle position θ2 of the motor 5 based on the acquired gear rotation angle restriction position Φ1 and the first relative rotation angle ΔΦ1. Specifically, after acquiring the gear rotation angle restriction position Φ1 in the parking lock state, the control unit 8 performs control to rotate the driven gear 62 in the Ruk direction by the first relative rotation angle ΔΦ1. Based on the rotation of the driven gear 62 in the Ruk direction by the first relative rotation angle ΔΦ1, the control unit 8 determines that the rotation angle position of the motor 5 detected by the motor rotation angle sensor 7 is the motor parking lock rotation angle position θ2. As a result, the motor parking lock rotation angle position θ2 is acquired. The acquired motor parking lock rotation angle position θ2 is stored in the volatile storage unit.

[0092] In this way, in the parking lock state, the control unit 8 aligns the rotational angle position of the driven gear 62 with the gear rotational angle restriction position Φ1, and then controls the rotational angle position of the motor 5 to be stored in the memory unit 81 as the motor parking lock rotational angle position θ2 based on rotating the driven gear 62 by the first relative rotation angle ΔΦ1.

[0093] <Difference between gear rotation angle restriction position and gear parking lock rotation angle position> Here, the positions of the connecting member 65 (for example, the second link 65b) in each of FIG. 5 and FIG. 6 are compared. In FIG. 5, the output shaft 65c rotates in the Ro1 direction in accordance with the rotation of the driven gear 62 in the Rlk direction due to the rotation of the motor 5. In FIG. 6, the output shaft 65c rotates in the Ro2 direction in accordance with the rotation of the driven gear 62 in the Ruk direction due to the rotation of the motor 5. However, since the reduction ratio of the transmission mechanism 6 is significantly increased from the gear rotation angle restriction position Φ1 toward the gear parking lock rotation angle position Φ2 (see FIG. 3), the output shaft 65c hardly rotates (for example, less than 1 degree) due to the rotation of the motor 5. Therefore, the difference between the gear rotation angle restriction position Φ1 and the gear parking lock rotation angle position Φ2 is quite small.

[0094] In this way, even if the motor 5 rotates in the parking lock state, the output shaft 65c hardly rotates, so the parking rod 3 does not move and the parking lock state is not unintentionally switched to the parking lock release state.

[0095] Comparison with Comparative Examples 7, when the reduction ratio of the transmission mechanism is constant, the difference between the gear rotation angle restriction position Φ1 and the gear parking lock rotation angle position Φ2 becomes larger than that in the present embodiment. In such a case, when the motor 5 is rotated in the parking lock state, the parking rod 3 also moves with the rotation of the output shaft 65c, and there is a risk that the parking lock state will be unintentionally switched to the parking lock release state.

[0096] In this way, in the vehicle parking device 100 of this embodiment, the increase in the reduction ratio due to the second point of the link member 64 of the transmission mechanism 6 is utilized to reduce the rotation of the output shaft 65c when obtaining the motor parking lock rotational angle position θ2.

[0097] <Difference in motor rotation angle position> Furthermore, as shown in FIG. 4, due to an increase in the reduction ratio by the transmission mechanism 6, the difference between the motor rotational angle restriction position θ1 of the motor 5 corresponding to the gear rotational angle restriction position Φ1 and the motor parking lock rotational angle position θ2 is greater than the difference between the output shaft rotational angle restriction position Ψ1 of the output shaft 65c corresponding to the gear rotational angle restriction position Φ1 and the output shaft parking lock rotational angle position Ψ2 of the output shaft 65c corresponding to the gear parking lock rotational angle position Φ2.

[0098] This is to prevent erroneous detection of the motor rotational angle restriction position θ1 and the motor parking lock rotational angle position θ2 due to a detection error of the motor rotational angle sensor 7 when the difference between the gear rotational angle restriction position Φ1 and the gear parking lock rotational angle position Φ2 is considerably small, as described above, if the difference between the motor rotational angle restriction position θ1 and the motor parking lock rotational angle position θ2 is reduced accordingly.

[0099] Furthermore, the difference between the motor parking lock release rotational angle position θ3 and the motor parking lock rotational angle position θ2 of the motor 5 is equal to or greater than the difference between the motor rotational angle restriction position θ1 and the motor parking lock rotational angle position θ2 (|θ3-θ2|≧|θ1-θ2|). This is to prevent the motor rotational angle restriction position θ1, the motor parking lock rotational angle position θ2, and the motor parking lock release rotational angle position θ3 from being erroneously detected as one another even if the motor rotational angle sensor 7 has a detection range for the rotational angle position of the motor 5 limited to a range equal to or less than a predetermined rotation angle.

[0100] <When the output shaft parking lock rotation angle position is not the initial position> In the above description, when the vehicle power supply is turned ON, the initial position of the rotational angle position of the output shaft 65c is the output shaft parking lock rotational angle position Ψ2. However, as shown in FIG. 8 and FIG. 9, there are also cases where the initial positions Pi1 and Pi2 of the rotational angle position of the output shaft 65c are not the output shaft parking lock rotational angle position Ψ2.

[0101] Specifically, as shown in Fig. 8, it is possible that the initial position Pi1 of the rotational angle position of the output shaft 65c is between the output shaft parking lock rotational angle position Ψ2 and the output shaft parking lock release rotational angle position Ψ3. Also, as shown in Fig. 9, it is possible that the initial position Pi2 of the rotational angle position of the output shaft 65c is the output shaft parking lock release rotational angle position Ψ3.

[0102] To deal with these cases, if the current value of the motor 5 does not increase when the driven gear 62 is rotated in accordance with the gear rotation angle restriction position Φ1 in the parking lock state, the control unit 8 rotates the driven gear 62 again toward the gear rotation angle restriction position Φ1 and determines whether the initial position is the output shaft parking lock release rotation angle position Ψ3 based on the current value of the motor 5 when the driven gear 62 is rotated again.

[0103] In other words, when the vehicle power is turned ON, if the initial rotational angle position of the output shaft 65c is either the initial position Pi1 or the initial position Pi2, even if the driven gear 62 is rotated in the Rlk direction by the first relative rotation angle Φ1, the rotation of the driven gear 62 is not stopped by the stopper 66, and the current value of the motor 5 does not increase.

[0104] In the case of the initial position Pi1 shown in FIG. 8, the control unit 8 performs control to rotate the driven gear 62 again in the Rlk direction by the third relative rotation angle ΔΦ3. When the drive gear 62 is rotated again, the control unit 8 performs control to determine that the initial position of the rotation angle position of the output shaft 65c is between the output shaft parking lock rotation angle position Ψ2 and the output shaft parking lock release rotation angle position Ψ3 (for example, the initial position Pi1 in FIG. 8) based on the increase in the current value of the motor 5. In addition, the control unit 8 determines that the rotation angle position of the driven gear 62 corresponding to the rotation angle position of the motor 5 detected by the motor rotation angle sensor 7 when the current value increases (motor rotation angle restriction position θ1) is the gear rotation angle restriction position Φ1, and performs control to stop the rotation of the driven gear 62. As a result, the gear rotation angle restriction position Φ1 is acquired. The subsequent control up to the storage unit 81 storing the motor parking lock rotation angle position θ2 is the same as that described above, and therefore a description thereof will be omitted.

[0105] 9, the control unit 8 performs control to rotate the driven gear 62 again in the Rlk direction by the third relative rotation angle ΔΦ3. When the driven gear 62 is rotated again, the control unit 8 performs control to determine that the initial position of the rotational angle position of the output shaft 65c is the output shaft parking lock release rotational angle position Ψ3 (for example, the initial position Pi2 in FIG. 9) based on the fact that the current value of the motor 5 does not increase.

[0106] Then, after determining the initial position, the control unit 8 performs control to rotate the driven gear 62 by the first relative rotation angle Φ1 in the Rlk direction. In this case, since the rotation angle position of the driven gear 62 is the gear parking lock rotation angle position Φ2, the rotation of the driven gear 62 is stopped by the stopper 66, and the current value of the motor 5 increases. The control unit 8 determines that the rotation angle position of the driven gear 62 corresponding to the rotation angle position of the motor 5 (motor rotation angle restriction position θ1) detected by the motor rotation angle sensor 7 when the current value increases is the gear rotation angle restriction position Φ1, and performs control to stop the rotation of the driven gear 62. As a result, the gear rotation angle restriction position Φ1 is acquired. The subsequent control up to the storage unit 81 storing the motor parking lock rotation angle position θ2 is the same as that described above, and therefore a description thereof will be omitted.

[0107] (Get motor parking lock release rotation angle position) As shown in FIG. 10, the control unit 8 performs control to acquire the motor parking lock release rotational angle position θ3 of the motor 5 based on the acquired motor parking lock rotational angle position θ2 and the second relative rotation angle ΔΦ2.

[0108] That is, when switching from the parking lock state (see FIG. 6) to the parking lock release state, the control unit 8 performs control to acquire the motor parking lock release rotational angle position θ3 of the motor 5 based on rotating the driven gear 62 by the second relative rotation angle ΔΦ2 (see FIG. 9) from the motor parking lock rotational angle position θ2. That is, when switching from the parking lock state to the parking lock release state, the control unit 8 performs control to store the rotational angle position of the motor 5 as the motor parking lock release rotational angle position θ3 in the storage unit 81 based on rotating the driven gear 62 by the second relative rotation angle ΔΦ2 after matching the rotational angle of the motor 5 to the motor parking lock rotational angle position θ2.

[0109] Here, switching from the parking lock state to the parking lock release state means that, based on an operation signal by the driver to switch to the parking lock release state, the parking rod 3 moves in the X1 direction to the parking lock release position P1 in the parking lock release state.

[0110] Specifically, after storing the motor parking lock rotation angle position θ2, and based on receiving an operation signal from the driver to switch to the parking lock release state, the control unit 8 performs control to determine whether or not the current rotation angle position of the motor 5 deviates from the stored motor parking lock rotation angle position θ2. This is performed because if there is a long time between the driver's operation of turning on the vehicle's power and the operation of switching to the parking lock release state, the rotation angle position of the motor 5 may deviate from the motor parking lock rotation angle position θ2 within the same position due to vibrations during idling of the vehicle, etc.

[0111] If the current rotational angle position of the motor 5 does not deviate from the stored motor parking lock rotational angle position θ2, the control unit 8 controls the rotational angle position of the motor 5 detected by the motor rotational angle sensor 7 after rotating the driven gear 62 by the second relative rotation angle ΔΦ2 to be stored in the volatile memory unit as the motor parking lock release rotational angle position θ3.

[0112] Furthermore, when the current rotational angle position of the motor 5 deviates from the stored motor parking lock rotational angle position θ2, the control unit 8 adjusts the rotational angle position of the motor 5 to the motor parking lock rotational angle position θ2, and then controls the driven gear 62 to rotate by the second relative rotation angle ΔΦ2.Then, the control unit 8 controls the rotational angle position of the motor 5 detected by the motor rotational angle sensor 7 after the driven gear 62 has been rotated by the second relative rotation angle ΔΦ2 to be stored in the volatile storage unit as the motor parking lock release rotational angle position θ3.

[0113] (Control for switching to parking lock state) As shown in FIG. 11, the control unit 8 performs control to align the output shaft 65c with the output shaft parking lock rotational angle position Ψ2 by returning it to the motor parking lock rotational angle position θ2 based on the acquired motor parking lock release rotational angle position θ3 and the second relative rotation angle ΔΦ2 (see FIG. 9).

[0114] That is, when switching from the parking lock release state (see FIG. 10) to the parking lock state, the control unit 8 performs control to return the rotational angle position of the motor 5 to the motor parking lock rotational angle position θ2 based on the rotation of the driven gear 62 from the motor parking lock release rotational angle position θ3 by the second relative rotation angle ΔΦ2 (see FIG. 9). That is, when switching from the parking lock release state to the parking lock state, the control unit 8 performs control to align the output shaft 65c with the output shaft parking lock rotational angle position Ψ2 by returning the rotational angle position of the motor 5 to the motor parking lock rotational angle position θ2 based on the rotation of the driven gear 62 by the second relative rotation angle ΔΦ2 after aligning the rotational angle of the motor 5 with the motor parking lock release rotational angle position θ3.

[0115] Here, switching from the parking lock release state to the parking lock state means that the parking rod 3 moves in the X2 direction based on an operation signal by the driver to switch to the parking lock state, thereby moving to the parking lock position P2 in the parking lock state.

[0116] Specifically, after storing the motor parking lock release rotational angle position θ3 and based on acquiring an operation signal from the driver to switch to the parking lock state, the control unit 8 performs control to determine whether the current rotational angle position of the motor 5 deviates from the stored motor parking lock release rotational angle position θ3.

[0117] When the current rotation angle position of the motor 5 is not deviated from the stored motor parking lock release rotation angle position θ3, the control unit 8 controls the driven gear 62 to rotate by the second relative rotation angle ΔΦ2. When the current rotation angle position of the motor 5 is deviated from the stored motor parking lock release rotation angle position θ3, the control unit 8 controls the driven gear 62 to rotate by the second relative rotation angle ΔΦ2 after aligning the current rotation angle position of the motor 5 with the motor parking lock release rotation angle position θ3.

[0118] Then, the control unit 8 performs control to determine whether or not the current rotation angle position of the motor 5 deviates from the stored motor parking lock rotation angle position θ2 after rotating the driven gear 62 by the second relative rotation angle ΔΦ2. If the current rotation angle position of the motor 5 does not deviate from the stored motor parking lock rotation angle position θ2, the control unit 8 performs control to terminate the operation of the device. Furthermore, if the current rotation angle position of the motor 5 deviates from the stored motor parking lock rotation angle position θ2 after rotating the driven gear 62 by the second relative rotation angle ΔΦ2, the control unit 8 performs control to align the current rotation angle position of the motor 5 with the motor parking lock rotation angle position θ2 and then terminate the operation of the device.

[0119] After the operation of the device has been completed, the driver turns off the vehicle power, and both the motor parking lock rotational angle position θ2 and the motor parking lock release rotational angle position θ3 stored in the volatile memory unit are erased.

[0120] (Rotation angle position control method) A rotation angle position control method performed by the control unit 8 will be described with reference to Fig. 12 to Fig. 14. This rotation angle position control method includes a motor parking lock rotation angle position acquisition method shown in Fig. 12, a motor parking lock release rotation angle position acquisition method shown in Fig. 13, and a parking lock state switching method shown in Fig. 14. In the rotation angle position control method, the motor parking lock rotation angle position acquisition method is performed after the motor parking lock rotation angle position acquisition method, and then the parking lock state switching method is performed. Below, the motor parking lock rotation angle position acquisition method, the motor parking lock release rotation angle position acquisition method, and the parking lock state switching method will be described in that order.

[0121] <Method for acquiring motor parking lock rotation angle position> 12, in step S101, the driven gear 62 is rotated in the Rlk direction by a first relative rotation angle ΔΦ1 in order to confirm the initial rotation angle position of the output shaft 65c (see FIG. 5). In step S102, it is determined whether the current value of the motor 5 has increased. If the current value of the motor 5 has increased, the process proceeds to step S103, and if the current value of the motor 5 has not increased, the process proceeds to step S106.

[0122] In step S103, it is determined that the initial rotational angle position of the output shaft 65c is the output shaft parking lock rotational angle position Ψ2, and that the current rotational angle position of the driven gear 62 is the gear rotational angle restriction position Φ1. In step S104, the driven gear 62 is rotated in the Ruk direction by the first relative rotation angle ΔΦ1 (see FIG. 6). In step S105, the current rotational angle of the motor 5 detected by the motor rotational angle sensor 7 is stored as the motor parking lock rotational angle position θ2, and then the motor parking lock rotational angle position acquisition method ends.

[0123] In step S106, it is determined that the initial position of the rotation angle position of the output shaft 65c is not the output shaft parking lock rotation angle position Ψ2. In step S107, the driven gear 62 is rotated in the Rlk direction by the third relative rotation angle ΔΦ3. In step S108, it is determined whether the current value of the motor 5 has increased. If the current value of the motor 5 has increased, the process proceeds to step S109, where it is determined that the initial position of the rotation angle position of the output shaft 65c is between the output shaft parking lock rotation angle position Ψ2 and the output shaft parking lock release rotation angle position Ψ3, and then the process returns to step S103. If the current value of the motor 5 has not increased, the process proceeds to step S110, where it is determined that the initial position of the rotation angle position of the output shaft 65c is the output shaft parking lock release rotation angle position Ψ3, and then the process returns to step S102.

[0124] <How to obtain the motor parking lock release rotation angle position> 13, in step S201, acquisition of an operation signal for releasing the parking lock by the driver is determined. In step S202, after acquisition of the operation signal, it is determined whether the current rotation angle position of the motor 5 is deviated from the motor parking lock rotation angle position θ2. If the current rotation angle position of the motor 5 is deviated, the process proceeds to step S203, where the current rotation angle position of the motor 5 is aligned with the motor parking lock rotation angle position θ2, and then the process returns to step S202.

[0125] If the current rotation angle position of the motor 5 has not shifted, the process proceeds to step S204. In step S204, the driven gear 62 is rotated in the Ruk direction by the second relative rotation angle ΔΦ2 (see FIG. 10). In step S205, the current rotation angle of the motor 5 detected by the motor rotation angle sensor 7 is stored as the motor parking lock release rotation angle position θ3, and then the motor parking lock release rotation angle position acquisition method ends.

[0126] <How to switch the parking lock state> As shown in Fig. 14, in step S301, acquisition of an operation signal for entering a parking lock state by the driver is determined. In step S302, after acquisition of the operation signal, it is determined whether the current rotation angle position of the motor 5 is deviated from the motor parking lock release rotation angle position θ3. If the current rotation angle position of the motor 5 is deviated, the process proceeds to step S303, where the current rotation angle position of the motor 5 is aligned with the motor parking lock release rotation angle position θ3, and then the process returns to step S302.

[0127] If the current rotation angle position of the motor 5 has not shifted, the process proceeds to step S304. In step S304, the driven gear 62 is rotated in the Rlk direction by the second relative rotation angle ΔΦ2 (see FIG. 11). In step S305, it is determined whether the current rotation angle position of the motor 5 has shifted with respect to the motor parking lock rotation angle position θ2. If the current rotation angle position of the motor 5 has not shifted, the parking lock state switching method ends. If the current rotation angle position of the motor 5 has shifted, the process proceeds to step S306, where the current rotation angle position of the motor 5 is adjusted to the motor parking lock rotation angle position θ2, and then the process returns to step S305.

[0128] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0129] In this embodiment, as described above, the vehicle parking device 100 includes a storage unit 81 that stores the first relative rotation angle ΔΦ1 and the second relative rotation angle ΔΦ2. The vehicle parking device 100 includes a control unit 8 that performs control to acquire the motor parking lock rotation angle position θ2 of the motor 5 based on the acquired gear rotation angle restriction position Φ1 and the first relative rotation angle ΔΦ1, and acquire the motor parking lock release rotation angle position θ3 of the motor 5 based on the motor parking lock rotation angle position θ2 and the second relative rotation angle ΔΦ2. As a result, the gear rotation angle restriction position Φ1 is acquired based on an increase in the current value of the motor 5, and the first relative rotation angle ΔΦ1 is stored in the storage unit 81, so that the motor parking lock rotation angle position θ2 can be acquired without using an output shaft rotation angle sensor. Furthermore, since the motor parking lock release rotational angle position θ3 is acquired based on the acquired motor parking lock rotational angle position θ2 and the first relative rotation angle ΔΦ1 stored in the memory unit 81, the motor parking lock release rotational angle position θ3 can be acquired without using an output shaft rotational angle sensor. As a result, the output shaft parking lock rotational angle position Ψ2 and the output shaft parking lock release rotational angle position Ψ3 can each be acquired without using an output shaft rotational angle sensor, so that an increase in the number of parts due to the output shaft rotational angle sensor can be suppressed. Furthermore, if the first relative rotation angle ΔΦ1 and the second relative rotation angle ΔΦ2 are stored in the storage unit 81, the output shaft parking lock rotation angle position Ψ2 and the output shaft parking lock release rotation angle position Ψ3 can each be acquired, so even if the output shaft parking lock rotation angle position Ψ2 and the output shaft parking lock release rotation angle position Ψ3 are erased when the vehicle power is turned off, the output shaft parking lock rotation angle position Ψ2 and the output shaft parking lock release rotation angle position Ψ3 can each be acquired when the vehicle power is turned on. As a result, there is no need for a dedicated backup power supply and a dedicated circuit for the backup power supply for storing the output shaft parking lock rotation angle position Ψ2 and the output shaft parking lock release rotation angle position Ψ3 after the vehicle power is turned off, so an increase in the number of parts can be suppressed.

[0130] In addition, in this embodiment, as described above, the transmission mechanism 6 includes a reduction mechanism having the driven gear 62 and configured such that the increase rate Up1 (degree of increase) of the reduction ratio from the gear rotation angle restriction position Φ1 to the gear parking lock rotation angle position Φ2 is greater than the increase rate Mup1 (degree of change) of the reduction ratio in the intermediate portion Mid between the gear parking lock rotation angle position Φ2 and the gear parking lock release rotation angle position Φ3. This increases the increase rate Up1 (degree of increase) of the reduction ratio from the gear rotation angle restriction position Φ1 to the gear parking lock rotation angle position Φ2, thereby reducing the drive amount of the output side end of the reduction mechanism due to the rotation of the motor 5 from the gear rotation angle restriction position Φ1 to the gear parking lock rotation angle position Φ2. As a result, the drive amount of the output side end of the reduction mechanism caused by the rotation of the driven gear 62 until it is stopped by the stopper 66 at the acquisition of the gear rotation angle restriction position Φ1 can be reduced, so that the parking rod 3 can be prevented from unintentionally moving from the parking lock position P2.

[0131] In this embodiment, as described above, the transmission mechanism 6 includes the output shaft 65c for outputting the torque of the motor 5 to the parking rod 3. Due to an increase in the reduction ratio by the reduction mechanism, the difference between the motor rotation angle restriction position θ1 of the motor 5 corresponding to the gear rotation angle restriction position Φ1 and the motor parking lock rotation angle position θ2 is larger than the difference between the output shaft rotation angle restriction position Ψ1 of the output shaft 65c corresponding to the gear rotation angle restriction position Φ1 and the output shaft parking lock rotation angle position Ψ2 of the output shaft 65c corresponding to the gear parking lock rotation angle position Φ2. Here, if the difference between the motor rotation angle restriction position θ1 and the motor parking lock rotation angle position θ2 is reduced in accordance with the difference between the output shaft rotation angle restriction position Ψ1 and the output shaft parking lock rotation angle position Ψ2, it is considered that the motor rotation angle restriction position θ1 and the motor parking lock rotation angle position θ2 will be erroneously detected as a result of a detection error of the sensor. Therefore, by making the difference between the motor rotation angle restriction position θ1 and the motor parking lock rotation angle position θ2 larger than the difference between the output shaft rotation angle restriction position Ψ1 and the output shaft parking lock rotation angle position Ψ2 by utilizing the increase in the reduction ratio by the reduction mechanism, it is possible to suppress erroneous detection of the motor rotation angle restriction position θ1 and the motor parking lock rotation angle position θ2 caused by the detection error of the sensor. Also, by making the difference between the output shaft rotation angle restriction position Ψ1 and the output shaft parking lock rotation angle position Ψ2 relatively small, the amount of rotation of the output shaft 65c caused by the rotation of the motor 5 can be reduced, so that it is possible to prevent the parking rod 3 from moving unintentionally from the parking lock position P2.

[0132] In addition, in this embodiment, as described above, when switching from the parking lock state to the parking lock release state, the control unit 8 performs control to acquire the motor parking lock release rotational angle position θ3 based on the rotation of the driven gear 62 by the second relative rotation angle ΔΦ2 from the motor parking lock rotational angle position θ2. As a result, since a process of rotating the driven gear 62 to the gear parking lock release rotational angle position Φ3 is necessary when switching from the parking lock state to the parking lock release state, the motor parking lock release rotational angle position θ3 can be acquired by utilizing this process. As a result, unlike a case where a dedicated process for acquiring the motor parking lock release rotational angle position θ3 is provided to rotate the driven gear 62, the process of acquiring the motor parking lock release rotational angle position θ3 can be efficiently performed.

[0133] In addition, in this embodiment, as described above, since the output shaft rotation angle sensor is not provided, there is no need for a structure for precisely arranging the output shaft rotation angle sensor with respect to the output shaft 65c. This makes it possible to prevent the structure of the vehicle parking device 100 from becoming complicated.

[0134] [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.

[0135] For example, in the above embodiment, the vehicle is an electric vehicle, but the present invention is not limited to this. In the present invention, the vehicle may be a hybrid vehicle equipped with an engine and a motor.

[0136] In the above embodiment, the vehicle parking device 100 includes the parking gear 1, the parking pole 2, the parking rod 3, the guide unit 4, the motor 5, the transmission mechanism 6, the motor rotation angle sensor 7, the control unit 8, and the case 9, but the present invention is not limited to this. In the present invention, the vehicle parking device may include a parking gear, a parking pole, a parking rod, a motor, a case, a transmission mechanism, a detent spring, and a detent plate. The detent plate may have grooves formed therein that correspond to the parking position and the non-parking position.

[0137] Also, the detent plate may have grooves corresponding to the parking position, reverse position, neutral position, and drive position. In this case, the memory unit stores a first relative rotation angle, a second relative rotation angle, a third relative rotation angle, a fourth relative rotation angle, and a fifth relative rotation angle. The first relative rotation angle is an angle indicating the difference between the gear rotation angle restriction position and the gear parking rotation angle position. The second relative rotation angle is an angle indicating the difference between the gear parking rotation angle position and the gear drive rotation angle position. The third relative rotation angle is an angle indicating the difference between the gear parking rotation angle position and the gear reverse rotation angle position. The fourth relative rotation angle is an angle indicating the difference between the gear reverse rotation angle position and the gear neutral rotation angle position. The fifth relative rotation angle is an angle indicating the difference between the gear neutral rotation angle position and the gear drive rotation angle position.

[0138] In the above embodiment, the reduction gear ratio of the transmission mechanism 6 increases from the gear rotation angle restriction position Φ1 toward the gear parking lock rotation angle position Φ2 of the driven gear 62, and increases from the gear parking lock release rotation angle position Φ3 of the driven gear 62 toward the first gear consideration point rotation angle position Φ4, but the present invention is not limited to this. In the present invention, it is sufficient that the reduction gear ratio of the transmission mechanism increases at least from the gear rotation angle restriction position toward the gear parking lock rotation angle position of the driven gear.

[0139] In the above embodiment, the transmission mechanism 6 includes the link member 64 and the connecting member 65, but the present invention is not limited to this. In the present invention, the transmission mechanism may have a structure other than a link mechanism as long as it increases the reduction ratio from the gear rotation angle restriction position toward the gear parking lock rotation angle position of the driven gear.

[0140] In the above embodiment, the stopper 66 has the engagement pin 66a and the slit 66b, but the present invention is not limited to this. In the present invention, the stopper may have a structure having a pin that abuts against the side surface of the driven gear, or may have a structure having an engagement between a convex portion and a concave portion, and the structure is not limited.

[0141] In the above embodiment, for convenience of explanation, the control process of the control unit 8 is explained using a flow-driven flowchart in which the process is performed in order according to the process flow, but the present invention is not limited to this. In the present invention, the control process of the control unit may be performed by an event-driven process in which the process is performed on an event-by-event basis. In this case, the control process may be performed completely event-driven, or may be performed in a combination of event-driven and flow-driven. [Explanation of symbols]

[0142] 3 Parking rod, 5 Motor, 6 Transmission mechanism, 8 Control unit, 62 Driven gear, 65c Output shaft, 66 Stopper, 81 Memory unit, 100 Vehicle parking device, Mid Intermediate portion, Mup1 Rise rate (degree of change), Mup2 Rise rate (degree of change), P1 Parking lock release position, P2 Parking lock position, Up1 Rise rate (degree of rise), ΔΦ1 First relative rotation angle, ΔΦ2 Second relative rotation angle, Φ1 Gear rotation angle restriction position, Φ2 Gear parking lock rotation angle position, Φ3 Gear parking lock release rotation angle position, Ψ1 Output shaft rotation angle restriction position, Ψ2 Output shaft parking lock rotation angle position, θ1 Motor rotation angle restriction position, θ2 Motor parking lock rotation angle position, θ3 Motor parking lock release rotation angle position

Claims

1. a motor that generates a driving force for switching the vehicle between a parking lock state and a parking lock release state; a transmission mechanism including a driven gear that rotates with the rotation of the motor and a stopper that stops the rotation of the driven gear at a gear rotation angle restriction position in the parking lock state, the transmission mechanism being connected to the motor and configured to increase a reduction ratio from the gear rotation angle restriction position toward a gear parking lock rotation angle position of the driven gear; a parking rod connected to the transmission mechanism and reciprocating between a parking lock position in the parking lock state and a parking lock release position in the parking lock release state; a storage unit that stores a first relative rotation angle between the gear rotation angle restriction position and the gear parking lock rotation angle position, and a second relative rotation angle between the gear parking lock rotation angle position and a gear parking lock release rotation angle position of the driven gear; a control unit that acquires the gear rotation angle restriction position based on an increase in a current value of the motor that occurs when the rotation of the driven gear is stopped by the stopper in the parking lock state, The control unit is configured to perform control to obtain a motor parking lock rotation angle position of the motor based on the acquired gear rotation angle restriction position and the first relative rotation angle, and to obtain a motor parking lock release rotation angle position of the motor based on the motor parking lock rotation angle position and the second relative rotation angle.

2. 2. The parking device for a vehicle as described in claim 1, wherein the transmission mechanism includes a reduction mechanism having the driven gear and configured such that a degree of increase in the reduction ratio from the gear rotation angle restriction position to the gear parking lock rotation angle position is greater than a degree of change in the reduction ratio in an intermediate portion between the gear parking lock rotation angle position and the gear parking lock release rotation angle position.

3. the transmission mechanism further includes an output shaft for outputting the torque of the motor to the parking rod, 3. The vehicle parking device according to claim 2, wherein a difference between the motor rotational angle restriction position of the motor corresponding to the gear rotational angle restriction position and the motor parking lock rotational angle position is greater than a difference between the output shaft rotational angle restriction position of the output shaft corresponding to the gear rotational angle restriction position and the output shaft parking lock rotational angle position of the output shaft corresponding to the gear parking lock rotational angle position due to an increase in the reduction ratio by the reduction mechanism.

4. 2. The parking device for a vehicle according to claim 1, wherein the control unit is configured to perform control to acquire the motor parking lock release rotational angle position based on rotating the driven gear by the second relative rotation angle from the motor parking lock rotational angle position when switching from the parking lock state to the parking lock release state.

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