JP2007314037A - Parking lock mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a parking lock mechanism capable of restraining the movement of a vehicle in the middle of parking by a compact structure. <P>SOLUTION: This parking lock mechanism 30 is provided with an interlock shaft 63 concentrically stored in a driving shaft 15 of a motor 12, to integrally rotate with the driving shaft 15 and free to move along a shaft center line 15b, a plurality of spline projected parts 63b formed at an outer peripheral part of the interlock shaft 63 and arranged in the circumferential direction, an interlock shaft engagement recessed part 64 formed at a planetary frame 24, recessed free to store a part of the interlock shaft 63 and on which a plurality of spline grooves 64a free to be engaged with the spline projected parts 63b are formed at an inner peripheral part and an actuator 34 to move the interlock shaft 63 to a second position P2 to make the spline projected parts 63b and the spline grooves 64a engaged with each other from a first position P1 to release the engagement of the spline projected parts 63b and the spline grooves 64a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a parking lock mechanism for an electric vehicle that includes a planetary gear type reduction mechanism and travels by a driving force of a motor.

Conventionally, an automobile is provided with a parking brake to prevent the vehicle from moving during parking. Further, in addition to the parking brake, the vehicle generally includes a parking lock mechanism that locks the drive shaft in order to more effectively prevent the vehicle from moving even when the vehicle is parked on a slope. It is. This mechanism is indispensable even in a vehicle that travels by driving a motor such as an electric vehicle. In a vehicle driven by a motor drive, the structure of this type of parking lock mechanism is similar to that provided in a conventional vehicle, that is, a gear provided on a drive shaft of a motor is engaged with the gear. Thus, a structure including a claw for locking the drive shaft of the motor is known. (For example, refer to Patent Document 1).
JP-A-2005-348467

  However, the parking lock mechanism disclosed in Patent Document 1 has a structure in which the drive shaft of the motor is locked by engaging the gear and the claw with each other. On the other hand, the parking lock mechanism needs to be strong enough to receive the force to move the vehicle even when the vehicle is parked on a slope.

  In other words, large gears and large claws are required. Therefore, the parking lock mechanism tends to be large. An increase in the parking lock mechanism is not preferable because a weight increase occurs.

  Accordingly, an object of the present invention is to provide a parking lock mechanism that can sufficiently prevent movement of a parked vehicle with a compact structure.

  The parking lock mechanism of the present invention is provided in an electric vehicle. The electric vehicle includes a wheel, a motor including a drive shaft, and a planetary gear type reduction mechanism. The planetary gear type reduction mechanism includes a sun gear that is assembled to the drive shaft and rotates integrally with the drive shaft, an internal gear that houses the sun gear, and the sun gear and the internal gear. A planetary gear that is interposed between the sun gear and the internal gear and revolves around the sun gear, and supports the planetary gear and rotates with the revolution of the planetary gear, A planetary frame that transmits the driving force of the motor to the wheel, and is interposed between the motor and the wheel. The parking lock mechanism is housed concentrically with the drive shaft inside the drive shaft, rotates integrally with the drive shaft, and is movable along the axis of the drive shaft with respect to the drive shaft. An interlock shaft, a plurality of protrusions formed on the outer periphery of the interlock shaft and arranged in the circumferential direction, provided on the planetary frame side and rotated integrally with the planetary frame, and one of the interlock shafts An interlock shaft engaging recess in which a plurality of grooves that can be engaged with the protrusion are formed on the inner peripheral portion, and the engagement between the protrusion and the groove is released. And an actuator that moves the interlock shaft from a first position to a second position where the protrusion engages with the groove.

  ADVANTAGE OF THE INVENTION According to this invention, the parking lock mechanism which can suppress the movement of the parked vehicle with a compact structure is obtained.

  A parking lock mechanism according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic view showing an automobile 10 provided with a parking lock mechanism 30. As shown in FIG. 1, the automobile 10 includes four wheels 11. The vehicle 10 is an electric vehicle, and each wheel 11 is driven by a motor 12.

  Therefore, the automobile 10 includes a planetary gear type reduction mechanism 20 as a reduction mechanism of the motor 12 and a parking lock mechanism 30 for each wheel 11. One motor 12, planetary gear speed reduction mechanism 20, and parking lock mechanism 30 are provided for each wheel 11.

  The arrangement and structure of the motor 12, the planetary gear speed reduction mechanism 20, and the parking lock mechanism 30 in each wheel 11 may be the same. Therefore, for example, the arrangement and structure of the motor 12, the planetary gear type reduction mechanism 20, and the parking lock mechanism 30 in the rear left wheel 11 will be described as a representative.

  FIG. 2 is a cross-sectional view showing in detail an enlarged range surrounded by F2 shown in FIG. FIG. 2 shows an enlarged view of the planetary gear type reduction mechanism 20 and the end 15a of the drive shaft 15 of the motor 12 for the wheel 11 arranged on the left side of the rear.

  As shown in FIG. 1, the planetary gear speed reduction mechanism 20 is interposed between the motor 12 and the wheel 11. The planetary gear type reduction mechanism 20 includes a sun gear 21, a plurality of planetary gears 22, an internal gear 23, and a planetary frame 24.

  As shown in FIG. 2, the sun gear 21 is assembled to the end 15 a of the drive shaft 15 of the motor 12. The end 15a is the end of the drive shaft 15 on the planetary gear speed reduction mechanism 20 side.

  FIG. 3 is a cross-sectional view of the planetary gear type speed reduction mechanism 20 shown along the line F3-F3 shown in FIG. As shown in FIG. 3, the internal gear 23 accommodates the sun gear 21 inside. A plurality of, for example, four planetary gears 22 are accommodated between the sun gear 21 and the internal gear 23. As shown in FIG. 2, the internal gear 23 is fixed to the housing 20 a (partially omitted in the drawing) of the planetary gear type reduction mechanism 20 by a plurality of pins 60. Furthermore, the housing 20a is fixed to the housing 12a of the motor 12, for example, by a plurality of bolts 61, for example. In FIG. 2, a part of the housing 12a of the motor 12 is indicated by a two-dot chain line. Thus, the internal gear 23 is fixed to the housing 20a by the pin 60, and the housing 20a is fixed to the housing 12a of the motor 12 by the bolt 61, so that the internal gear 23 is fixed and does not rotate.

  As shown in FIG. 2, the planetary frame 24 supports the rotation shaft 22 a of each planetary gear 22. As described above, since the internal gear 23 is fixed, each planetary gear 22 revolves around the sun gear 21 when the sun gear 21 rotates. As a result, the planetary frame 24 also rotates.

  A shaft 62 that supports a hub (not shown) that supports the wheel 11 is assembled to the tip 24 a of the planetary frame 24. Since the shaft 62 is integrally assembled with the planetary frame 24, the shaft 62 rotates integrally with the planetary frame 24. As a result, the planetary frame 24 transmits the driving force of the motor 12 to the wheel 11. The shaft 62 covers the end portion 15a of the drive shaft 15 in a direction along the axial center line 15b. The planetary frame 24 and the shaft 62 may be integrally formed with each other.

  The parking lock mechanism 30 includes a drive shaft 15 of the motor 12, an interlock shaft 63, an actuator 34 (shown in FIG. 1), and an interlock shaft engaging recess 64.

  The drive shaft 15 of the motor 12 will be described in detail. As shown in FIGS. 2 and 3, the drive shaft 15 is disposed concentrically with the drive shaft 15 and parallel to the axis 15 b of the drive shaft 15. An accommodating hole 15e is formed. A plurality of spline grooves 15f parallel to the axial center line 15b are formed in the circumferential direction on the inner peripheral portion of the accommodation hole 15e.

  The interlock shaft 63 is parallel to the axis 15b of the drive shaft 15 and is accommodated in the accommodation hole 15e. A spline protrusion 63 b that engages with the spline groove 15 f of the accommodation hole 15 e is formed on the outer peripheral portion of the interlock shaft 63. A plurality of spline protrusions 63 b are formed in the circumferential direction of the interlock shaft 63 in parallel with the axis 15 b of the drive shaft 15. That is, the interlock shaft 63 is a spline shaft. The spline protrusion 63b is an example of the protrusion referred to in the present invention.

  2 and 3 show a state in which the interlock shaft 63 is accommodated in the accommodation hole 15e. The interlock shaft 63 is slidable along the axial line 15b of the drive shaft 15 with respect to the accommodation hole 15e.

  As shown in FIG. 1, the actuator 34 is disposed, for example, on the opposite side of the planetary gear type reduction mechanism 20 with respect to the drive shaft 15. The actuator 34 can move the interlock shaft 63. The actuator 34 is connected to the ECU 40. The ECU 40 drives the actuator 34 according to the position of a shift lever (not shown), for example.

  As shown in FIG. 2, the interlock shaft engaging recess 64 is formed in a portion of the shaft 62 that faces the end portion 15 a of the drive shaft 15. That is, the interlock shaft engaging recess 64 is formed on the planetary frame 24 side. When the shaft 62 and the planetary frame 24 are integrated, the interlock shaft engaging recess 64 is formed in the planetary frame 24.

  The interlock shaft engaging recess 64 has a concave shape that opens toward the distal end portion 63 a of the interlock shaft 63 and can accommodate the distal end portion 63 a of the interlock shaft 63.

  A spline groove 64 a that engages with a spline protrusion 63 b formed at the distal end portion 63 a of the interlock shaft 63 is formed in the inner peripheral portion of the interlock shaft engaging recess 64. The spline grooves 64a are parallel to the axis 15b of the drive shaft 15 and are formed in the circumferential direction. The spline groove 64a is an example of the groove referred to in the present invention.

  In the present embodiment, the interlock shaft engaging recess member 65 in which the spline groove 64 a is formed is fixed to the recess 66 formed in the shaft 62, thereby forming the interlock shaft engaging recess 64. Yes.

  When the interlock shaft 63 moves along the axis 15 b of the drive shaft 15, the distal end portion 63 a of the interlock shaft 63 is accommodated in the interlock shaft engaging recess 64. And the spline protrusion 63b engages with the spline groove 64a. FIG. 4 shows a state in which the interlock shaft 63 is accommodated in the interlock shaft engaging recess 64.

  As shown in FIG. 2, when the interlock shaft 63 is in a position where the interlock shaft 63 is not housed in the interlock shaft engaging recess 64, the position is defined as a first position P1. As shown in FIG. 4, when the interlock shaft 63 is in a position where the interlock shaft 63 is accommodated in the interlock shaft engaging recess 64, the position is defined as a second position P <b> 2.

  Next, the operation of the parking lock mechanism 30 will be described.

  When the automobile 10 stops traveling and parks, the driver moves the position of the shift lever to the parking position. When the automobile 10 is traveling, that is, when the shift lever is not in the parking position, the interlock shaft 63 is in the first position P1 as shown in FIG.

  Receiving the information that the position of the shift lever has been moved to parking, the ECU 40 drives the actuator 34 so that the interlock shaft 63 moves from the first position P1 to the second position P2, as shown in FIG. When the actuator 34 is driven, the interlock shaft 63 moves from the first position P1 to the second position P2.

  When the interlock shaft 63 is moved from the first position P1 to the second position P2, the distal end portion 63a of the interlock shaft 63 is accommodated in the interlock shaft engaging recess 64, and the spline of the interlock shaft 63 is The protrusion 63 b engages with the spline groove 64 a in the interlock shaft engaging recess 64. In other words, the drive shaft 15 and the shaft 62 (on the planetary frame 24 side) are connected via the interlock shaft 63.

  However, the rotational speed of the drive shaft 15 is different from the rotational speed of the planetary frame 24. The rotational speed of the planetary frame 24 is decelerated by the planetary gear type reduction mechanism 20 more than the rotational speed of the drive shaft 15. As a result, when the planetary frame 24 and the drive shaft 15 are connected via the interlock shaft 63 as described above, the rotation of the drive shaft 15 is stopped due to the difference in rotational speed between them. That is, since the drive shaft 15 is locked, movement of the parked automobile 10 is suppressed.

  When the driver moves the position of the shift lever from the parking position to another position, the ECU 40 drives the actuator 34 to move the interlock shaft 63 from the second position P2 to the first position P1. As a result, the drive shaft 15 of the motor 12 is unlocked.

  The parking lock mechanism 30 configured as described above can have a compact structure. This point will be specifically described.

  As described above, in the parking lock mechanism 30, the spline protrusion 63 b formed on the interlock shaft 63 engages with the spline groove 64 a formed in the interlock shaft engaging recess 64. A plurality of spline protrusions 63 b are formed in the circumferential direction of the outer peripheral portion of the interlock shaft 63. A plurality of spline grooves 64 a are formed in the circumferential direction of the inner peripheral portion of the interlock shaft engaging recess 64.

  As a result, when the interlock shaft 63 engages with the interlock shaft engaging recess 64, it is possible to increase the number of portions that contact each other. Therefore, even if the interlock shaft 63 and the interlock shaft engaging recess 64 are formed small, the drive shaft 15 can be sufficiently locked. That is, the parking lock mechanism 30 can be formed compactly.

  Further, the spline protrusion 63b and the spline groove 64a are engaged with each other, and the interval between the spline protrusions 63b adjacent in the circumferential direction is reduced and the interval between the spline grooves 64a adjacent in the circumferential direction is reduced. Therefore, the backlash when the spline protrusion 63b engages with the spline groove 64a can be reduced. As a result, even when the drive shafts 15 of the left and right motors 12 are locked, the automobile 10 can be prevented from moving greatly due to the influence of backlash.

  Further, even when the teeth of the internal gear 23 are shaved or when the teeth of the planetary gear 22 are shaved, the automobile 10 can be moved. This point will be specifically described.

  As described above, when the teeth of the internal gear 23 are shaved or when the teeth of the planetary gear 22 are shaved, the planetary gear 22 cannot revolve around the sun gear 21. Is not transmitted to the wheel 11. However, if the drive shaft 15 and the planetary frame 24 side (the shaft 62 in the present embodiment) are connected via the interlock shaft 63 by setting the interlock shaft 63 to the second position P2, the driving force of the motor 12 will be described. Is transmitted directly to the planetary frame 24. As a result, the rotational torque of the motor 12 is transmitted to the wheel 11, so that the automobile 10 can be moved.

Schematic which shows a motor vehicle provided with the parking lock mechanism which concerns on one Embodiment of this invention. Sectional drawing which expands and shows the range of F2 shown by FIG. 1 in detail. Sectional drawing of the planetary gear type reduction mechanism shown along the F3-F3 line | wire shown by FIG. Sectional drawing which shows the state which has the interlock shaft shown by FIG. 2 in a 2nd position.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Automobile (electric vehicle), 11 ... Wheel, 12 ... Motor, 21 ... Sun gear, 22 ... Planetary gear, 23a ... Internal gear, 24 ... Planetary frame, 30 ... Parking lock mechanism, 34 ... Actuator, 63 ... Inter Lock shaft, 63b ... spline protrusion (projection), 64 ... interlock shaft engaging recess, 64a ... spline groove (groove), P1 ... first position, P2 ... second position.

Claims (1)

Wheels,
A motor with a drive shaft;
A sun gear that is assembled to the drive shaft and rotates integrally with the drive shaft, an internal gear that accommodates the sun gear inside, and interposed between the sun gear and the internal gear and the A planetary gear that meshes with both the sun gear and the internal gear and revolves around the sun gear, and supports the planetary gear and rotates with the revolution of the planetary gear, and the driving force of the motor on the wheel A planetary frame that transmits the planetary gear, and a planetary gear speed reduction mechanism that is interposed between the motor and the wheel,
A parking lock mechanism provided in an electric vehicle comprising:
An interlock shaft that is housed concentrically with the drive shaft inside the drive shaft and rotates integrally with the drive shaft, and is movable along the axis of the drive shaft with respect to the drive shaft;
A plurality of protrusions formed on the outer periphery of the interlock shaft and arranged in the circumferential direction;
A plurality of grooves that are provided on the planetary frame side and that rotate integrally with the planetary frame and that can accommodate a part of the interlock shaft, and that can be engaged with the protrusions on the inner periphery. Interlock shaft engaging recess to be
An actuator that moves the interlock shaft from a first position where the engagement between the protrusion and the groove is released to a second position where the protrusion engages with the groove. A parking lock mechanism.

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