Shift device

Abstract

To provide a shift device suppressing a failure due to deformation of rotation regulating means or deterioration in a reference position detection accuracy due to elastic deformation of the rotation regulating means.SOLUTION: (a) An actuator 120 includes: a motor 22; a deceleration mechanism 28 decelerating rotation input from the motor 22 and outputting the rotation from an actuator output shaft 36; and rotation regulating means 26 provided to a power transmission path PT between the motor 22 and the actuator output shaft 36. (b) The rotation regulating means 26 regulates rotation in the power transmission path PT. In such a way, the rotation regulating means 26 is provided to the power transmission path PT on the side of the motor 22 rather than on the side of the actuator output shaft 36. Failure due to deformation of the rotation regulating means 26 and / or deterioration in accuracy in detecting a shift range reference position due to elastic deformation of the rotation regulating means 26 are / is suppressed when compared with a case where the rotation regulating means 26 is provided after the actuator output shaft 36.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a shift device having an actuator and a speed reduction mechanism that reduces the rotation input from the motor and outputs it from an output shaft, and the shift range is switched by the actuator.

Background Art

[0002] There is known a shift device having an actuator and a speed reduction mechanism that reduces the rotation input from the motor and outputs it from an output shaft, and the shift range is switched by the actuator. For example, the one described in Patent Document 1 is such a device. In the shift device described in Patent Document 1, the shift range is switched by the rotation that is finally decelerated by the speed reduction mechanism and has an increased torque.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the shift device described in Patent Document 1, when learning (identifying) the reference position (= rotational position) of the shift range, a large load is applied to the rotation restricting means that restricts the rotation that is finally decelerated and has an increased torque. Therefore, there is a risk that a failure may occur due to deformation of the rotation restricting means caused by repeated application of the load, or that the detection accuracy of the reference position may decrease due to elastic deformation of the rotation restricting means.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a shift device capable of suppressing a failure due to deformation of the rotation restricting means and a decrease in the detection accuracy of the reference position due to elastic deformation of the rotation restricting means.

Means for Solving the Problem

[0006] The gist of the present invention is a shift device in which a shift range is switched by an actuator, the actuator including a motor, a first reduction mechanism that decelerates the rotation input from the motor and outputs it from an output shaft, and rotation restricting means for restricting the rotation of a rotating member provided in a power transmission path between the motor and the output shaft.

Effect of the Invention

[0007] According to the shift device of the present invention, the actuator includes a motor, a first reduction mechanism that decelerates the rotation input from the motor and outputs it from an output shaft, and rotation restricting means for restricting the rotation of a rotating member provided in a power transmission path between the motor and the output shaft. Thus, the rotation restricting means is provided in the power transmission path on the motor side rather than on the output shaft side of the first reduction mechanism. Therefore, when learning the reference position of the shift range, the load applied to the rotation restricting means is alleviated as compared with the case where the rotation restricting means is provided after the output shaft of the first reduction mechanism. Accordingly, failures due to deformation of the rotation restricting means and deterioration of the detection accuracy of the reference position due to elastic deformation of the rotation restricting means are suppressed.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying out the Invention

[0009] Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings. In each embodiment, the drawings are appropriately simplified or deformed, and the dimensional ratios, shapes, etc. of each part are not necessarily drawn accurately.

Example

[0010] Fig. 1 is a schematic configuration diagram of a shift device 10 according to Embodiment 1 of the present invention.

[0011] The shift device 10 is a device mounted on a vehicle and switches the shift range of the vehicle. The shift range of the shift device 10 is switched by an actuator 20. The shift range represents the power transmission state from a power source for traveling (for example, an engine or a traveling motor) in the vehicle to a pair of drive wheels. For example, the shift device 10 switches the shift range from one of the P range and the non-P range to the other. The P range is a shift range in which the vehicle is in a neutral state and a pair of drive wheels are mechanically fixed so as not to rotate, that is, a parking range. The non-P range is other shift ranges other than the P range, for example, an R range (= reverse traveling range) that enables the vehicle to travel backward, an N range (neutral range) in which the power transmission from the power source for traveling to a pair of drive wheels is blocked, a D range (= forward traveling range) that enables the vehicle to travel forward, and the like.

[0012] The shift device 10 is a shift-by-wire system. The actuator 20 includes a motor 22, a speed reduction mechanism 28 that reduces and outputs the rotation input from the motor 22, and a rotation restricting means 26 provided in a power transmission path PT between the motor 22 and the speed reduction mechanism 28. The motor 22 is, for example, a well-known stepping motor. The rotation of the motor 22 is output from the actuator output shaft 36 through the motor output shaft 30, which is the output shaft of the motor 22, and the speed reduction mechanism 28 in order from the motor 22 side. The actuator output shaft 36 is the output shaft of the actuator 20. When the actuator output shaft 36 rotates, the operating state of the parking lock device 40 is switched. When the operating state of the parking lock device 40 is switched, the shift range is switched. The speed reduction mechanism 28 corresponds to the "first speed reduction mechanism" in the present invention.

[0013] The electronic control unit 90 is configured to include a so-called microcomputer including, for example, a CPU, a RAM, a ROM, an input / output interface, etc. The CPU performs signal processing according to a program stored in the ROM in advance while using the temporary storage function of the RAM. By controlling the rotation of the motor 22 by the electronic control unit 90, the shift range is switched.

[0014] The electronic control unit 90 receives, for example, a motor rotation angle θmt [deg] representing the rotation position of the motor output shaft 30 based on a detection value by a rotation angle sensor 80. A motor control signal Smt for controlling the rotation of the motor 22 is output from the electronic control unit 90 to the motor 22.

[0015] FIG. 2 is an explanatory diagram of the parking lock device 40 shown in FIG. 1.

[0016] The parking lock device 40 includes a manual shaft 42, a plate 44, a parking gear 46, a parking lock pole 48, a parking rod 52, a spring 54, and a tapered member 56. The actuator output shaft 36 is non-rotatably connected to the manual shaft 42. The rotation center line of the manual shaft 42 is the axis C1. The rotation of the actuator output shaft 36 is transmitted to the tapered member 56 sequentially via the manual shaft 42, the plate 44, and the parking rod 52.

[0017] The parking gear 46 is a gear connected to a pair of drive wheels. The parking lock pole 48 can be moved closer to and away from the parking gear 46 by being rotated around a single axis. The parking lock pole 48 has a claw portion 50 that meshes with the parking gear 46 when moved closer to the parking gear 46. When the claw portion 50 is meshed with the parking gear 46, the pair of drive wheels are fixed non-rotatably. One end of the parking rod 52 supports the tapered member 56 through which the tapered member 56 that engages with the parking lock pole 48 is inserted. The other end of the parking rod 52 is connected to the lower end of the plate 44. The tapered member 56 is moved to the small-diameter side or the large-diameter side of the tapered member 56 as the parking rod 52 is moved by the rotation of the plate 44. The spring 54 biases the tapered member 56 to its small-diameter side.

[0018] Figure 2 shows the parking lock device 40 in an operating state, i.e., the shift range is in the P range. In this state, the claw portion 50 of the parking lock pole 48 meshes with the parking gear 46, thereby preventing the rotation of a pair of drive wheels connected to the parking gear 46. In this state, when the manual shaft 42 is rotated in the direction of arrow A and one end of the parking rod 52 is moved in the direction of arrow B, the parking lock pole 48 is moved in the direction of arrow C by the movement of the tapered member 56 provided at the tip of one end of the parking rod 52. When the parking lock pole 48 is moved in the direction of arrow C, the claw portion 50 is moved to a position where it does not mesh with the parking gear 46, and the lock of a pair of drive wheels connected to the parking gear 46 is released. The state where the lock of a pair of drive wheels connected to the parking gear 46 is released is a state where the parking lock device 40 is in a non-operating state, i.e., the shift range is in a non-P range.

[0019] In a state where the parking lock device 40 is in a non-operating state, i.e., the shift range is in a non-P range, the claw portion 50 of the parking lock pole 48 is in a position where it does not mesh with the parking gear 46. In this state, when the manual shaft 42 is rotated in the direction opposite to arrow A and one end of the parking rod 52 is moved in the direction opposite to arrow B, the parking lock pole 48 is moved in the direction opposite to arrow C by the movement of the tapered member 56. When the parking lock pole 48 is moved in the direction opposite to arrow C, the claw portion 50 is moved to a position where it meshes with the parking gear 46, and a pair of drive wheels connected to the parking gear 46 are locked, i.e., the shift range is in the P range.

[0020] In this way, when the parking lock device 40 is switched to the operating state, the shift range is switched to the P range, and when the parking lock device 40 is switched to the non-operating state, the shift range is switched to the non-P range. The parking lock device 40 is a range switching device for switching the shift range.

[0021] FIG. 3 is an explanatory view of a swing slider crank mechanism 60 that forms part of the actuator 20 shown in FIG. 1.

[0022] The swing slider crank mechanism 60 has a well-known configuration including a short lever 62 and a long lever 66. FIG. 3(a) shows a state where the longitudinal direction of the short lever 62 and the longitudinal direction of the long lever 66 are the same. FIG. 3(b) shows a state where the short lever 62 rotates counterclockwise to the maximum extent (dashed-dotted line) and a state where the short lever 62 rotates clockwise to the maximum extent (two-dot chain line).

[0023] One end of the short lever 62 is fixedly connected to the motor output shaft 30. The rotation center line of the motor output shaft 30 and the short lever 62 is the axis C2. A pin 64 is provided at the other end of the short lever 62. The pin 64 rotates along a circle C2f centered on the axis C2. One end of the long lever 66 is fixedly connected to the actuator output shaft 36. The rotation center line of the actuator output shaft 36 and the long lever 66 is the axis C1. A long hole 68 extending in the longitudinal direction of the long lever 66 is provided at the other end of the long lever 66. The pin 64 provided on the short lever 62 is slidable within the long hole 68. The long hole 68 is configured such that the pin 64 is slidable only within a rotation range Rc2, for example, within a 180° range of the short lever 62. Thereby, the short lever 62 is rotatable only within the rotation range Rc2 of the circle C2f centered on the axis C2, and the long lever 66 is rotatable only within a rotation range Rc1 (<Rc2) of the circle C1f centered on the axis C1. The short lever 62 and the long lever 66 correspond to the "rotating members" in the present invention. The pin 64 and the long hole 68 are rotation restricting means 26, which correspond to the "rotation restricting means" in the present invention. The torque transmitted in the short lever 62 and the long lever 66 is lower than the output torque of the actuator output shaft 36.

[0024] In the swing slider crank mechanism 60, the rotation of the motor output shaft 30 is decelerated and output to the actuator output shaft 36. Further, the rotation of the long lever 66 provided in the power transmission path PT between the motor output shaft 30 and the actuator output shaft 36 is restricted by the contact of the pin 64 provided on the short lever 62 with the long hole wall portion 68w. The long hole wall portion 68w is the wall portion on the actuator output shaft 36 side in the longitudinal direction of the long lever 66 in the long hole 68. The "rotation restricting means" and the "first speed reduction mechanism" in the present invention are constituted by the swing slider crank mechanism 60.

[0025] FIG. 4 is an explanatory diagram of an example of the reference position P1 of the P range and the reference position P2 of the non-P range of the shift range in the shift device 10. In FIG. 4, the longitudinal direction of the long lever 66 centered on the axis C1 is schematically shown. At this time, the actuator output shaft 36 can rotate within a predetermined rotation range Rc1 centered on the axis C1. One side of the predetermined rotation range Rc1 is the rotation position where the short lever 62 rotates counterclockwise to the maximum and the rotation is restricted by the pin 64 and the long hole 68, that is, the rotation position Pedg1 where the rotation is restricted on the P range side. The other side of the predetermined rotation range Rc1 is the rotation position where the short lever 62 rotates clockwise to the maximum and the rotation is restricted by the pin 64 and the long hole 68, that is, the rotation position Pedg2 where the rotation is restricted on the non-P range side.

[0026] For example, the reference position P1 of the P range is set at a position rotated by a predetermined angle φ from the rotation position Pedg1 toward the center side of the predetermined rotation range Rc1. For example, the reference position P2 of the non-P range is set at a position rotated by a predetermined angle φ from the rotation position Pedg2 toward the center side of the predetermined rotation range Rc1. The predetermined angle φ is an angle determined in advance experimentally or by design. As shown in FIG. 4, the angle range of the P range and the angle range of the non-P range are each a predetermined angle range including the reference position P1 of the P range and the reference position P2 of the non-P range.

[0027] For example, the electronic control unit 90 learns the rotation positions Pedg1 and Pedg2 in advance by rotating the motor output shaft 30 and the actuator output shaft 36 until the rotation is restricted by the rotation restricting means 26. The electronic control unit 90 learns in advance the reference position P1 of the P range and the reference position P2 of the non-P range based on the rotation positions Pedg1 and Pedg2. During the learning, a load is applied to the rotation restricting means 26. The electronic control unit 90 controls the motor rotation angle θmt based on the learned reference position P1 of the P range and the reference position P2 of the non-P range. Specifically, when switching the shift range to the P range, the motor rotation angle θmt is controlled so that the longitudinal direction of the long lever 66 is within the angular range of the P range. When switching the shift range to the non-P range, the motor rotation angle θmt is controlled so that the longitudinal direction of the long lever 66 is within the angular range of the non-P range. If the reduction ratio in the actuator 20 is the reduction ratio γ (= θmt / θout), the motor rotation angle θmt is represented by the product of the reduction ratio γ and the rotation angle θout of the actuator output shaft 36.

[0028] According to the present embodiment, the actuator 20 includes a motor 22, a speed reduction mechanism 28 that reduces the rotation input from the motor 22 and outputs it from the actuator output shaft 36, and rotation restricting means 26 (= pin 64 and long hole 68) that restricts the rotation of the short lever 62 and the long lever 66 provided in the power transmission path PT between the motor 22 and the actuator output shaft 36. In this way, the rotation restricting means 26 is provided in the power transmission path PT on the motor 22 side rather than the actuator output shaft 36 which is also the output shaft of the speed reduction mechanism 28. Therefore, when learning the reference position P1 of the P range or the reference position P2 of the non-P range which are the reference positions of the shift range, compared with the case where the rotation restricting means is provided after the actuator output shaft 36, the load applied to the rotation restricting means 26 is alleviated. Therefore, failures due to deformation of the rotation restricting means 26 and deterioration of the detection accuracy of the reference position due to elastic deformation of the rotation restricting means 26 are suppressed.

[0029] According to this embodiment, the rotation restricting means 26 and the speed reduction mechanism 28 are constituted by a rocking slider crank mechanism 60. Thus, by constituting the rotation restricting means 26 and the speed reduction mechanism 28 by the rocking slider crank mechanism 60, the load applied to the rotation restricting means 26 when learning the reference position of the shift range is alleviated. Thereby, failures due to deformation of the rocking slider crank mechanism 60 which is the rotation restricting means 26 and a decrease in detection accuracy of the reference position due to elastic deformation are suppressed.

Embodiment

[0030] FIG. 5 is a schematic configuration diagram of a shift device 110 according to Embodiment 2 of the present invention.

[0031] The shift device 110 is substantially the same as the shift device 10 in the aforementioned Embodiment 1, except that an actuator 120 is provided instead of the actuator 20. Therefore, the description will focus on the parts different from Embodiment 1, and the same reference numerals will be given to the substantially common parts and the description will be omitted as appropriate.

[0032] The actuator 120 includes a motor 22, a speed reduction mechanism 124 that decelerates and outputs the rotation input from the motor 22, a speed reduction mechanism 128 that decelerates the rotation input from the speed reduction mechanism 124 and outputs it from the actuator output shaft 36, and a rotation restricting means 126 provided between the speed reduction mechanism 124 and the speed reduction mechanism 128 in the power transmission path PT between the motor 22 and the actuator output shaft 36. The rotation of the motor 22 is output from the actuator output shaft 36 through the motor output shaft 30, the speed reduction mechanism 124, and the speed reduction mechanism 128 in order from the motor 22 side. The speed reduction mechanism 128 and the speed reduction mechanism 124 respectively correspond to the "first speed reduction mechanism" and the "second speed reduction mechanism" in the present invention.

[0033] The speed reduction mechanism 128 is a well-known speed reduction gear device in which, for example, a small-diameter gear and a large-diameter gear are engaged.

[0034] FIG. 6 is an explanatory diagram of a worm gear 160 that constitutes a part of the actuator 120 shown in FIG. 5.

[0035] The worm gear 160 has a well-known configuration including a worm 162 and a worm wheel 164 meshing with the worm 162. The worm 162 is formed, for example, on the motor output shaft 30. The rotation center lines of the motor output shaft 30 and the worm 162 are the axis C2. The rotation center line of the worm wheel 164 is the axis C3. When viewed in the direction of the axis C3, the worm wheel 164 is fan-shaped centered on the axis C3. On the peripheral surface of the worm wheel 164 that is arc-shaped when viewed in the direction of the axis C3, meshing teeth that mesh with the worm 162 are provided. The worm wheel 164 is fixedly connected to the input shaft of the speed reduction mechanism 128. The worm gear 160 decelerates the rotation of the motor output shaft 30 and outputs it to the speed reduction mechanism 128, functioning as the speed reduction mechanism 124.

[0036] On the rotation orbit of the worm wheel 164, a pair of wall portions 166 are provided. The rotation of the worm wheel 164 is restricted by the pair of wall portions 166. Fig. 6(a) shows a state where the worm wheel 164 rotates counterclockwise to the maximum extent until it contacts one of the pair of wall portions 166 and its rotation is restricted, and Fig. 6(b) shows a state where the worm wheel 164 rotates clockwise to the maximum extent until it contacts the other of the pair of wall portions 166 and its rotation is restricted. The worm wheel 164 corresponds to the "rotating member" in the present invention. The wall portion 166 is the rotation restricting means 126 and corresponds to the "rotation restricting means" in the present invention. The torque transmitted in the worm wheel 164 is lower than the output torque of the actuator output shaft 36.

[0037] According to this embodiment, (a) the actuator 120 includes a motor 22, a speed reduction mechanism 128 that reduces the rotation input from the motor 22 and outputs it from the actuator output shaft 36, and a rotation restricting means 126 (= wall portion 166) that restricts the rotation of a worm wheel 164 provided in the power transmission path PT between the motor 22 and the actuator output shaft 36. (b) The actuator 120 further includes a speed reduction mechanism 124 different from the speed reduction mechanism 128 between the motor 22 and the speed reduction mechanism 128 in the power transmission path PT. The same effects as those of the aforementioned Example 1 exhibited along with the configuration of (a) are achieved. Further, by having the speed reduction mechanism 124 described in (b), since the rotation is reduced by the speed reduction mechanism 124 and then the rotation is restricted by the rotation restricting means 126, the reference position of the shift range can be set with high accuracy.

[0038] According to this embodiment, (a) the speed reduction mechanism 124 includes a worm 162 connected to the motor 22 and a fan-shaped worm wheel 164 that meshes with the worm 162 and is connected to the speed reduction mechanism 124. (b) A wall portion 166 provided on the rotation orbit of the worm wheel 164 is the rotation restricting means 126 that restricts rotation. In this way, the worm 162 and the fan-shaped worm wheel 164 connected to the speed reduction mechanism 128 are provided, and the wall portion 166 is provided on the rotation orbit of the worm wheel 164. Thereby, the rotation of the worm 162 is reduced and transmitted to the worm wheel 164, and the rotation of the worm wheel 164 is restricted by the wall portion 166, so that the reference position of the shift range can be set with high accuracy.

[0039] Note that the above are the embodiments of the present invention, and the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art without departing from the gist thereof.

[0040] In the aforementioned Example 1, the rotation range Rc2 was 180 [deg], but the present invention is not limited to this aspect.

[0041] In the aforementioned Example 1, the "rotation restricting means" and the "first speed reduction mechanism" in the present invention were configured by the oscillating slider crank mechanism 60. In the aforementioned Example 2, (a) the "second speed reduction mechanism" was composed of a worm 162 connected to the motor 22 and a sector-shaped worm wheel 164 that meshed with the worm 162 and was connected to the speed reduction mechanism 128, and (b) the "rotation restricting means" was composed of a wall portion 166 provided on the rotation orbit of the worm wheel 164. However, the "first speed reduction mechanism", "second speed reduction mechanism", and "rotation restricting means" in the present invention are not limited to such aspects.

Explanation of Signs

[0042] 10, 110: Shift device, 20, 120: Actuator, 22: Motor, 26, 126: Rotation restricting means, 28: Speed reduction mechanism (first speed reduction mechanism), 36: Actuator output shaft (output shaft), 60: Oscillating slider crank mechanism, 62: Short lever (rotating member), 64: Pin (rotation restricting means), 66: Long lever (rotating member), 68: Long hole (rotation restricting means), 124: Speed reduction mechanism (second speed reduction mechanism), 162: Worm, 164: Worm wheel (rotating member), 166: Wall portion (rotation restricting means), PT: Power transmission path

Claims

1. A shift device in which a shift range is switched by an actuator, wherein the actuator includes a motor, a first reduction mechanism that reduces the rotation input from the motor and outputs it from an output shaft, and rotation restricting means for restricting the rotation of a rotating member provided in a power transmission path between the motor and the output shaft. A shift device characterized by the above.

2. The actuator further includes a second reduction mechanism different from the first reduction mechanism between the motor and the rotation restricting means in the power transmission path. The shift device according to claim 1, characterized by the above.

3. The rotation restricting means and the first reduction mechanism are constituted by a swing slider crank mechanism. The shift device according to claim 1 or 2, characterized by the above.

4. The second reduction mechanism includes a worm connected to the motor and a fan-shaped worm wheel that meshes with the worm and is connected to the first reduction mechanism. The rotation restricting means is a wall portion provided on a rotation orbit of the worm wheel. The shift device according to claim 2, characterized by the above.

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