JP2018127067A - Driving force distribution device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving force distribution device for a vehicle for suitably reducing an abnormal sound generated from a cut-off/contact device.SOLUTION: A return angle Φ around a second rotation axis C2 of a first cam member 78 when the first cam member 78 moves backward is made larger than a looseness angle Ψ up to an output shaft 62 from rear wheels 16L and 16R, so that even if a rotation speed of the output shaft 62 is reduced when a synchronizer 90 becomes nonoperation by moving the first cam member 78 backward, looseness up to the output shaft 62 from the rear wheels 16L and 16R is stopped earlier than when an outer peripheral cut-off/contact tooth 66a of a cut-off/contact sleeve 66 meshes with an inner peripheral cut-off/contact tooth 54a of a ring gear 54. Thus, a rotation speed of the output shaft 62 is recovered and in a state where difference between the rotation speed of the ring gear 54 and the rotation speed of the output shaft 62 is comparatively small, the outer peripheral cut-of/contact tooth 66a of the cut-off/contact sleeve 66 is meshed with the inner peripheral cut-off/contact tooth 54a of the ring gear 54.SELECTED DRAWING: Figure 2

Description

  In the vehicle driving force distribution device, the present invention is generated from the first connecting / disconnecting teeth of the connecting / disconnecting sleeve and the second connecting / disconnecting teeth of the ring gear when the connecting / disconnecting sleeve is moved from the non-engaging position to the engaging position. The present invention relates to a technique for suitably reducing sound.

  A connecting / disconnecting device for connecting / disconnecting a power transmission path between the ring gear and the input shaft by moving the connecting / disconnecting sleeve between the meshing position and the non-meshing position by one reciprocating movement of the pair of cam members, and the pair of cams A vehicle driving force distribution device including a synchronization device that synchronizes the rotation of the ring gear and the rotation of the input shaft when the connection / disconnection sleeve is moved beyond the non-engagement position by one forward movement of a member. Are known. For example, the vehicle driving force distribution device described in Patent Document 1 is that.

Japanese Unexamined Patent Publication No. 2016-155502

  By the way, in the vehicle driving force distribution device of Patent Document 1, a pair of electronic control couplings are provided instead of the differential device provided in the vehicle driving force distribution device, for example, the vehicle driving force distribution device. Is arranged on the rear wheel side, that is, the reciprocating movement of one of the pair of cam members moves the connection sleeve between the meshing position and the non-meshing position so that the ring gear and the output shaft A connecting / disconnecting device for connecting / disconnecting a power transmission path between the ring gear and a rotation of the output shaft when the connecting / disconnecting sleeve is moved beyond the non-engagement position by the forward movement of one of the pair of cam members. And a pair of electronically controlled couplings that transmit torque output from the output shaft to each of the pair of drive wheels Vehicular drive force distribution device comprising a it can be considered. In this case, there is a problem that a relatively large noise may be generated from the connection / disconnection device. In the vehicle driving force distribution device as described above, when the pair of electronic control couplings are provided, the connection sleeve in the connection / disconnection device is not engaged by the backlash from the drive wheel to the output shaft. It has been found that a relatively large noise is generated from the first connecting / disconnecting tooth of the connecting / disconnecting sleeve and the second connecting / disconnecting tooth of the ring gear when moved to the meshing position. In the connection / disconnection device, when the connection / disconnection sleeve is moved from the non-engagement position to the engagement position by one reciprocating movement of the pair of cam members, the connection / disconnection is performed by one forward movement of the pair of cam members. When the sleeve is moved beyond the non-engagement position, the rotation speed of the output shaft is raised to the rotation speed of the ring gear by the synchronizer, but the second connection / disconnection tooth of the connection / disconnection sleeve is moved to the first position of the ring gear. When one of the pair of cam members is moved backward in order to mesh with one connecting / disconnecting tooth, the synchronizer is deactivated, and therefore the backlash is transmitted by the driving force transmitted from the pair of driving wheels to the output shaft. The rotation speed of the output shaft is reduced until it is clogged. Thereby, for example, the second connecting / disconnecting tooth of the connecting / disconnecting sleeve is connected to the ring gear while the rotational speed of the output shaft decreases and the difference between the rotating speed of the output shaft and the rotating speed of the ring gear is relatively large. It has been found that a relatively large noise is generated from the first connecting / disconnecting tooth of the connecting / disconnecting sleeve and the second connecting / disconnecting tooth of the ring gear when engaged with the first connecting / disconnecting tooth.

  The present invention has been made in the background of the above circumstances, and an object of the present invention is to provide a vehicle driving force distribution device that can suitably reduce abnormal noise generated from a connection / disconnection device.

  The gist of the first invention is that (a) a ring gear, an output shaft, a pair of electronically controlled couplings that transmit torque output from the output shaft to each of a pair of drive wheels, the ring gear, A connection / disconnection device that connects / disconnects a power transmission path to / from the output shaft; and a synchronization device that synchronizes the rotation of the ring gear and the rotation of the output shaft. The driving force transmitted to the ring gear is transmitted to the pair of electrons. A vehicle driving force distribution device that distributes to each of the pair of drive wheels via a control coupling, wherein (b) the connection / disconnection device engages with a first connection / disconnection tooth formed on the ring gear. Two disengagement teeth, provided on the output shaft so as not to rotate relative to the output shaft and movable in the direction of the rotation axis, A connection sleeve that is moved between a meshing position that meshes with the first connection and disconnection tooth and a non-meshing position where the second connection and disconnection tooth does not mesh with the first connection and disconnection tooth; and (c) the connection and disconnection sleeve A return spring that is biased from the non-meshing position toward the meshing position, (d) an actuator, and (e) provided so as to be relatively rotatable with respect to the output shaft, and resisting the biasing force of the return spring. A piston for moving the connecting / disconnecting sleeve to the non-engagement position; (f) a pair of cam members that are relatively rotated about the rotation axis by the operation of the actuator; and a pair of cam members that are opposed to each other. When the pair of cam members are rotated relative to each other, one of the pair of cam members faces the piston. A ball cam to be moved; and (g) a plurality of stages of engaging teeth, provided on the output shaft so as not to be relatively rotatable and immovable in the direction of the rotation axis, A holder for positioning the connecting / disconnecting sleeve at the meshing position and the non-meshing position by latching a piston, and (h) moving the piston by reciprocal movement of one of the pair of cam members, The connection / disconnection sleeve is moved between the non-engagement position and the engagement position by changing the position at which the piston is latched by (i), and (i) the synchronization device is configured such that the connection / disconnection sleeve is not in engagement. When moved beyond the position, a synchronous operation is performed to synchronize the rotation of the ring gear and the rotation of the output shaft. (J) The return angle of the one cam member around the rotation axis when one of the pair of cam members moves backward is larger than the backlash angle from the drive wheel to the output shaft. There is.

  According to the first aspect of the present invention, (b) the connection / disconnection device has a second connection / disconnection tooth that can mesh with the first connection / disconnection tooth formed on the ring gear, and the output shaft cannot rotate relative to the output shaft. The second connecting / disconnecting tooth is movable between a meshing position where the second connecting / disconnecting tooth meshes with the first connecting / disconnecting tooth and a non-engaging position where the second connecting / disconnecting tooth does not mesh with the first connecting / disconnecting tooth. A connecting / disconnecting sleeve, (c) a return spring that urges the connecting / disconnecting sleeve from the non-engagement position toward the engagement position, (d) an actuator, and (e) relative rotation with respect to the output shaft. And a piston that moves the connection sleeve to the non-engagement position against the urging force of the return spring, and (f) the actuator is actuated to relatively rotate around the rotation axis. A pair of cam members, and spherical rolling elements sandwiched between groove-shaped cam surfaces formed on opposite surfaces of the pair of cam members, respectively, and when the pair of cam members are relatively rotated, A ball cam in which one of the pair of cam members is moved toward the piston; and (g) a plurality of engaging teeth, provided on the output shaft so as not to be relatively rotatable and immovable in the direction of the rotation axis, And (h) one of the pair of cam members, the holder positioning the connection / disconnection sleeve at the meshing position and the non-meshing position by latching the piston with any one of the plurality of stages of latching teeth. The reciprocating movement of the piston moves the piston, and the holder stops the piston by changing the position where the piston is latched. (I) When the connecting / disconnecting sleeve is moved beyond the non-engagement position, the synchronizing device synchronizes the rotation of the ring gear and the rotation of the output shaft. (J) When one of the pair of cam members moves backward, the return angle of the one cam member around the rotation axis is a backlash angle from the drive wheel to the output shaft. Has been bigger than. For this reason, even if one of the pair of cam members moves backward to deactivate the synchronizing device and the rotational speed of the output shaft decreases, the second connecting / disconnecting teeth of the connecting / disconnecting sleeve are not connected to the first ring gear. Since the backlash from the drive wheel to the output shaft is filled earlier than the engagement with the connection / disconnection tooth, the output is faster than the second connection / disconnection tooth of the connection / disconnection sleeve engages with the first connection / disconnection tooth of the ring gear. When the rotational speed of the shaft is restored and the difference between the rotational speed of the ring gear and the rotational speed of the output shaft is relatively small, the second connecting / disconnecting tooth of the connecting / disconnecting sleeve is Bite. Accordingly, it is possible to suitably suppress abnormal noise generated from the first connecting / disconnecting teeth of the connecting / disconnecting sleeve and the second connecting / disconnecting teeth of the ring gear.

1 is a skeleton diagram schematically illustrating a configuration of a four-wheel drive vehicle to which the present invention is preferably applied. It is sectional drawing explaining the structure of the driving force distribution apparatus for rear wheels provided in the four-wheel drive vehicle of FIG. FIG. 3 is a schematic diagram for explaining the operating principle of a moving mechanism provided in the rear wheel driving force distribution device of FIG. 2. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 2, illustrating a second cam member of a ball cam provided in the rear wheel driving force distribution device in FIG. 2. FIG. 5 is a cross-sectional view taken along the line VV in FIG. 4 and illustrates a ball cam provided in the rear wheel driving force distribution device in FIG. 2. While the four-wheel drive vehicle shown in FIG. 1 is traveling straight ahead, both the first clutch and the second clutch are engaged to release the disconnected state from the disconnected state where both the first clutch and the second clutch are released. FIG. 6 is a diagram showing the rotational speed of the front wheels, the rotational speed of the rear wheels, the rotational speed of the ring gear, and the rotational speed of the output shaft until the time until

  In an embodiment of the present invention, (a) a pair of cams with respect to the other of the pair of cam members when the pair of cam members are relatively rotated on cam surfaces formed on the pair of cam members, respectively. In a first rotation direction around one of the rotation axes of the member, a first inclined surface that is inclined so that the depth of the groove becomes deeper toward the first rotation direction, and toward the first rotation direction. A second inclined surface that is inclined so that the depth of the groove becomes shallower is formed adjacently, and (b) an angle of the first inclined surface of the pair of cam members with respect to the opposing surfaces is It is the same as the angle of the second inclined surface of the pair of cam members with respect to the opposing surfaces, (c) the return angle is Φ, the angle of the first inclined surface of the pair of cam members with respect to the opposing surfaces is θ, Formed on each of the pair of cam members The radius of a circle passing through the center of the plurality of groove-shaped cam surfaces is R, the return amount of the connecting sleeve when the one of the pair of cam members is moved back is A, the circumference When the rate is π, the return angle Φ is expressed by the equation Φ = (A / tan θ) × (180 / (π × R)). For this reason, even if one of the pair of cam members moves backward to deactivate the synchronizing device and the rotational speed of the output shaft decreases, the second connecting / disconnecting teeth of the connecting / disconnecting sleeve are not connected to the first ring gear. The backlash from the drive wheel to the output shaft is filled sooner than it engages with the connecting / disconnecting teeth.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a skeleton diagram schematically illustrating a configuration of a four-wheel drive vehicle 10 to which the present invention is preferably applied. In FIG. 1, a four-wheel drive vehicle 10 corresponds to a first power transmission path for transmitting power of an engine 12 to left and right front wheels 14L and 14R corresponding to main drive wheels, and power of the engine 12 to sub drive wheels. An FF-based four-wheel drive device having a second power transmission path for transmitting left and right rear wheels (a pair of drive wheels) 16L and 16R is provided. In the two-wheel drive state of the four-wheel drive vehicle 10, the driving force transmitted from the engine 12 via the automatic transmission 18 is transmitted to the left and right front wheels 14L via the front wheel driving force distribution device 20 and the left and right axles 22L and 22R. , 14R. In this two-wheel drive state, at least the first clutch 24 provided in the transfer 26 is released, and the propeller shaft 28, the rear wheel driving force distribution device (vehicle driving force distribution device) 30, and the rear wheels 16L, 16R. No driving force is transmitted to However, in the four-wheel drive state, in addition to the above-described two-wheel drive state, the first clutch 24 and the second clutch (connecting / disconnecting device) 32 are engaged together, and the propeller shaft 28 and the rear wheel drive force distribution. The driving force from the engine 12 is transmitted to the device 30 and the rear wheels 16L and 16R.

  As shown in FIG. 1, the front wheel driving force distribution device 20 is provided so as to be rotatable about the first rotation axis C1, and is engaged with the output gear 18a of the automatic transmission 18 and a differential case fixed to the ring gear 20r. 20c and a differential gear mechanism 20d accommodated in the differential case 20c, and the drive transmitted to the ring gear 20r while allowing differential rotation of the left and right axles 22L, 22R connected to the front wheels 14L, 14R. The force is transmitted to the left and right axles 22L and 22R. The differential case 20c is formed with an inner peripheral meshing tooth 20a that fits with a first outer peripheral spline tooth 34a formed at the end of the cylindrical input shaft 34 provided on the transfer 26 on the differential case 20c side. .

  As shown in FIG. 1, the transfer 26 includes a cylindrical ring gear 38 that meshes with a driven pinion 36 connected to the front wheels 14 </ b> L and 14 </ b> R side ends of the propeller shaft 28 to drive the propeller shaft 28, and the engine 12. A cylindrical input shaft 34 to which a part of the driving force transmitted to the front wheels 14L and 14R is input via the differential case 20c, and the input shaft 34 and the ring gear 38 in the power transmission path from the differential case 20c to the propeller shaft 28. A first clutch 24 that connects and disconnects the power transmission path between the engine 12 and the engine 12 when the first clutch 24 is engaged and the power transmission path between the input shaft 34 and the ring gear 38 is connected. Part of the driving force transmitted to the front wheels 14L, 14R of the left and right rear wheels 16L, 16R via the propeller shaft 28 It is adapted to be output.

  As shown in FIG. 1, the first clutch 24 is disposed on the input shaft 34 so as to be movable in the direction of the first rotation axis C <b> 1 with respect to the input shaft 34 and not relatively rotatable with respect to the input shaft 34. A connection / disconnection sleeve 40 having outer peripheral connection / disconnection teeth 40a, a coil-shaped first return spring 42 for urging the connection / disconnection sleeve 40 from the first non-engagement position to the first engagement position, and the connection / disconnection sleeve 40 Is moved in the direction of the first rotation axis C1 to move the connection sleeve 40 between the first meshing position and the first non-meshing position, and an actuator 46 that drives the movement mechanism 44. Is provided. The first engagement position is a position where the connection / disconnection sleeve 40 is moved in the direction of the first rotation axis C <b> 1 by the moving mechanism 44 and the outer peripheral connection / disconnection tooth 40 a of the connection / disconnection sleeve 40 is engaged with the inner peripheral connection / disconnection tooth 38 a of the ring gear 38. In the first meshing position, the ring gear 38 and the input shaft 34 cannot be rotated relative to each other. Further, the first non-engagement position is such that the connection sleeve 40 is moved in the direction of the first rotation axis C1 by the moving mechanism 44 and the outer peripheral connection / disconnection tooth 40a of the connection / disconnection sleeve 40 is engaged with the inner peripheral connection / disconnection tooth 38a of the ring gear 38. In the first non-meshing position, the ring gear 38 and the input shaft 34 can be rotated relative to each other. The moving mechanism 44 includes a synchronization device that synchronizes the rotational speed of the input shaft 34, that is, the connection sleeve 40 and the rotation speed of the ring gear 38 when the connection sleeve 40 moves from the non-engagement position to the engagement position. 48 is arranged.

  As shown in FIGS. 1 and 2, the rear wheel driving force distribution device 30 is connected to the propeller shaft 28 on the side of the rear wheels 16L, 16R on the power transmission path from the propeller shaft 28 to the left and right rear wheels 16L, 16R. A ring gear 54 that meshes with a drive pinion 52 coupled to the part via a coupling 50, and a first bearing on the case member 56 of the rear wheel driving force distribution device 30 that is rotatable about a second rotation axis (rotation axis) C2. 58 and a cylindrical output shaft 62 supported via the second bearing 60, and a pair of torques transmitted from the output shaft 62 to the rear wheels 16L and 16R to the left and right rear wheels 16L and 16R, respectively. Left electronic control coupling (electronic control coupling) 64L and right electronic control coupling (electronic control coupling) 64R (see FIG. 1) When, and a second clutch 32 which disconnects the power transmission path between the ring gear 54 and the output shaft 62. The left electronic control coupling 64L and the right electronic control coupling 64R are wet multi-plate clutch type electronic control couplings that respectively control the transmission torque between the output shaft 62 and the left and right rear wheels 16L, 16R. . Further, the rear wheel driving force distribution device 30 is configured so that the driving force transmitted from the engine 12 to the ring gear 54 via the propeller shaft 28 in the four wheel driving state of the four wheel driving vehicle 10 is a pair of left electronic control couplings 64L. And distributed to the rear wheels (drive wheels) 16L and 16R via the right electronic control coupling 64R.

  As shown in FIG. 2, the second clutch 32 has an outer peripheral connecting / disconnecting tooth (second connecting / disconnecting tooth) 66 a that can mesh with an inner peripheral connecting / disconnecting tooth (first connecting / disconnecting tooth) 54 a formed on the ring gear 54. A second meshing position (meshing position) where the outer peripheral connection / disconnection tooth 66a meshes with the inner peripheral connection / disconnection tooth 54a and the outer peripheral connection / disconnection. The connection sleeve 66 that is moved in the direction of the second rotation axis C2 between the second non-engagement position (non-engagement position) in which the teeth 66a do not mesh with the inner peripheral connection / disconnection tooth 54a, and the connection sleeve 66 is the second connection position. By moving the coil-shaped first return spring (return spring) 68 urging from the non-engagement position toward the second mesh position and the connection sleeve 66 in the second rotational axis C2 direction, the connection sleeve 66 is moved. The second meshing position and the A moving mechanism 70 for moving to and from the second non-engagement position, an actuator 72 for driving the moving mechanism 70 is provided. The first return spring 68 is interposed between the annular member 74 provided adjacent to the second bearing 60 and the connection / disconnection sleeve 66 in a preloaded state, and is connected / disconnected by the first return spring 68. The sleeve 66 is biased toward the first bearing 58 in the direction of the second rotation axis C2.

  As shown in FIG. 2, the moving mechanism 70 is provided so as to be rotatable relative to the output shaft 62, and the connection sleeve 66 is moved to the second non-engagement position against the urging force of the first return spring 68. A piston 76 to be moved, a pair of annular first cam members (cam members) 78 and a second cam member (cam members) 80 that are relatively rotated around the second rotation axis C2 by the operation of the actuator 72, and a pair of first cam members. The first cam member 78 and the second cam member 80 each have a spherical rolling element 82 sandwiched between groove-like cam surfaces 78b and 80b formed on opposing surfaces 78a and 80a facing each other. When the cam member 78 and the second cam member 80 are relatively rotated around the second rotation axis C <b> 2, one first cam of the pair of the first cam member 78 and the second cam member 80. A ball cam 84 in which the material 78 is moved toward the piston 76, a second return spring 86 that biases the first cam member 78 toward the second cam member 80, and a plurality of stages (two stages in this embodiment). The first latching tooth (see FIG. 3) 88a and the second latching tooth (see FIG. 3) 88b are provided on the output shaft 62 so as not to rotate relative to the output shaft 62 and to move in the direction of the second rotation axis C2. There is provided a holder 88 for positioning the connection sleeve 66 at the second meshing position and the second non-meshing position by latching the piston 76 with the latching teeth 88a or the second latching teeth 88b. The moving mechanism 70 includes a rotation speed (rotation) of the ring gear 54 and a rotation speed (rotation) of the output shaft 62 when the connection / disconnection sleeve 66 moves from the second non-engagement position to the second engagement position. Is provided.

  As shown in FIG. 2, the ball cam 84 includes, for example, a pair of annular first cam members 78 and a first cam member 78 that are interposed between the piston 76 and the first bearing 58 so as to overlap in the direction of the second rotation axis C2. The two cam members 80, and the first cam member 78 and the second cam member 80, which are formed at three locations in the circumferential direction (see FIG. 4), have depths D (see FIG. 5) that change in the circumferential direction. And three spherical rolling elements 82 sandwiched between opposing groove-shaped cam surfaces 78b and 80b. The first cam member 78 and the second cam member 80 are rotated relative to each other around the second rotation axis C2. As a result, the first cam member 78 and the second cam member 80 are separated in the direction of the second rotation axis C2. Although not shown on the inner peripheral surface of the first cam member 78, the inner peripheral meshing teeth meshing with the outer peripheral spline teeth formed on the output shaft 62 so as not to be relatively rotatable and movable in the direction of the second rotational axis C2. Is formed. Accordingly, when the output shaft 62 rotates around the second rotation axis C2, for example, the first cam member 78 also rotates around the second rotation axis C2, and when the actuator 72 is not operated, for example, the second cam member is rotated. 80 rotates integrally with the first cam member 78 via the spherical rolling element 82.

  In the electromagnetic coil, the ball cam 84, and the movable piece 92, which are the actuator 72 configured as described above, for example, the actuator 72 operates when the output shaft 62 rotates around the second rotation axis C2 while the vehicle is traveling. When the movable piece 92 is attracted to the electromagnetic coil by the electromagnetic coil, the rotational braking torque is transmitted to the second cam member 80 by the movable piece 92 being attracted to the electromagnetic coil which is a non-rotating member. . Therefore, when the actuator 72 is actuated from the non-actuated state, the first cam member 78 and the second cam member 80 are relatively rotated by the rotational braking torque, and the first cam member 78 is interposed via the spherical rolling element 82. The second sleeve 60 moves toward the piston 76 against the urging force of the first return spring 68 and the second return spring 86 in the direction of the second rotation axis C2, and the connection sleeve 66 is located on the second bearing 60 side via the piston 76 and the like. Moved to. Further, when the actuator 72 is deactivated from the activated state, the connection / disconnection sleeve 66 is moved to the first bearing 58 side by the urging force of the first return spring 68, and the first urging force of the second return spring 86 is used. The cam member 78 moves in a direction approaching the second cam member 80. The movable piece 92 and the second cam member 80 are connected so as not to be relatively rotatable.

  FIG. 3 is a schematic diagram for explaining the operating principle of the moving mechanism 70, and shows a state where the annular piston 76, the pressing portion 78c of the annular first cam member 78, and the annular holder 88 are developed. As shown in FIG. 3, the annular piston 76 is formed with a protrusion 76 a protruding from the holder 88 side. Further, the annular holder 88 is periodically formed with two stages of first latching teeth 88a and second latching teeth 88b connected in the circumferential direction for latching the protrusion 76a of the piston 76. Reference numeral 88 denotes a position fixed to the output shaft 62. Further, the pressing portion 78c of the annular first cam member 78 has the same shape as the first latching teeth 88a and the second latching teeth 88b formed on the holder 88, but has a shape shifted by a predetermined phase in the circumferential direction. The first receiving teeth 78d and the second receiving teeth 78e in two stages are periodically formed so as to extend in the circumferential direction and receive the protrusion 76a of the piston 76. The pressing portion 78c of the annular first cam member 78 is provided so as not to rotate relative to the holder 88 and to be movable in the direction of the second rotation axis C2, and is urged by the urging force of the first return spring 68 and the second return spring 86. In contrast, the piston 76 is moved by one stroke of the ball cam 84. Stoppers 78f and 88c that stop the protrusion 76a of the piston 76 from slipping are provided on the inclined surfaces of the second receiving teeth 78e of the pressing portion 78c of the first cam member 78 and the second engaging teeth 88b of the holder 88, respectively. Is provided.

  FIGS. 3A and 3E show a state in which the protrusion 76a of the piston 76 is latched by the first latching tooth 88a of the holder 88 and the connection / disconnection sleeve 66 is in the second meshing position. As shown in FIGS. 3A and 3E, in the state where the projection 76a projecting from the piston 76 is located at the position latched by the first latching tooth 88a of the holder 88, the first The pressing portion 78c of the cam member 78 is positioned at the base position. FIG. 3B shows that the piston 76 is attached to the first return spring 68 and the second return spring 86 for the moving stroke ST by energizing the electromagnet as the actuator 72, that is, by driving the ball cam 84 according to the operating state of the actuator 72. It shows a state where it is moved from its base position against the power. In this process, the piston 76 is moved by the pressing portion 78c of the first cam member 78 to be separated from the holder 88, and the piston 76 is inclined by the slope 78g of the first receiving tooth 78d of the pressing portion 78c of the first cam member 78. Slip down. In addition, the dashed-dotted line shown by (b) of FIG. 3 shows the base position of the press part 78c of the 1st cam member 78 of (a) of FIG. 3 in order to demonstrate moving stroke ST. FIG. 3C shows the biasing force of the second return spring 86 when the pressing portion 78c of the first cam member 78 is not energized to the electromagnet which is the actuator 72, that is, the ball cam 84 is not driven by the non-operating state of the actuator 72. Accordingly, the state is shown in which it is returned by the moving stroke ST and positioned at the base position. In this process, the protrusion 76a of the piston 76 is latched by the second latching tooth 88b of the holder 88, and the connection / disconnection sleeve 66 is held in the second non-engagement position. In FIG. 3D, the first return spring 68 and the second return spring 86 are moved by the moving stroke ST by the driving of the ball cam 84 when the pressing portion 78c of the first cam member 78 is energized to the electromagnet as the actuator 72 again. It shows a state in which it is moved from its base position against the urging force. In this process, the piston 76 is further moved to the first return spring 68 side and the connecting / disconnecting sleeve 66 is moved to the second bearing 60 side beyond the second non-engagement position. And the connecting sleeve 66, that is, the output shaft 62, are rotationally synchronized. Next, as shown in FIG. 3E, the pressing portion 78 c of the first cam member 78 moves according to the urging force of the second return spring 86 by the non-drive of the ball cam 84 due to the non-energization of the electromagnet as the actuator 72. When returned by the stroke ST and positioned at the base position, the protrusion 76a of the piston 76 is latched by the first latching tooth 88a of the holder 88, and the connection sleeve 66 is positioned at the second meshing position.

  Thereby, in the moving mechanism 70, the piston 76 is moved in the circumferential direction by the reciprocating movement of the first cam member 78 by the ball cam 84, and the piston is moved by the first and second engaging teeth 88a and 88b formed on the holder 88. By changing the position where the projection 76a of 76 is hooked, the connection / disconnection sleeve 66 can be moved between the second non-meshing position and the second meshing position. That is, when the piston 76 is reciprocated once by the first cam member 78, the protrusion 76a of the piston 76 is hooked on the second hooking tooth 88b of the holder 88, and the connection sleeve 66 is moved to the second non-meshing position. Is located. When the piston 76 is reciprocated twice by the first cam member 78, that is, when the piston 76 is reciprocated once by the first cam member 78 in a state where the connection sleeve 66 is in the second non-engagement position, The projection 76a of the 76 is disengaged from the second latching tooth 88b of the holder 88, and the projection 76a of the piston 76 is latched by the first latching tooth 88a of the holder 88 by the urging force of the first return spring 68. The sleeve 66 is positioned at the second meshing position.

  As shown in FIG. 2, the synchronizer 90 includes an annular member 94 interposed between the connection sleeve 66 and the piston 76, and an outer periphery of the annular member 94 that is formed on the outer periphery of the second rotation axis C2. Between the slightly conical outer peripheral friction surface 94a and the inner peripheral contact surface 54b formed on the inner periphery of the end of the ring gear 54 on the piston 76 side and slightly inclined with respect to the second rotation axis C2. A pair of annular first friction engagement members 96 and a second friction engagement member 98 are provided. The annular member 94 is provided such that it cannot rotate relative to the output shaft 62 and is movable in the direction of the second rotation axis C2. Further, since a part of the annular member 94 is sandwiched between the connection sleeve 66 and the piston 76 by the urging force of the first return spring 68, the annular member 94 is rotated by the second rotation of the connection sleeve 66 and the piston 76. It moves in the direction of the second rotation axis C2 in conjunction with the movement in the direction of the axis C2. The first friction engagement member 96 is in sliding contact with a second conical inner peripheral friction surface 98a formed on the inner peripheral surface of the second friction engagement member 98 and slightly inclined with respect to the second rotational axis C2. A possible first conical outer peripheral friction surface 96a and a first conical inner peripheral friction surface 96b that can slide in contact with the conical outer peripheral friction surface 94a of the annular member 94 are formed. The second friction engagement member 98 includes a second conical outer peripheral contact surface 98b that can contact the aforementioned second conical inner peripheral friction surface 98a and the conical inner peripheral contact surface 54b of the ring gear 54. And are formed.

  Therefore, when the connection sleeve 66 is in the second non-engagement position and the piston 76 is reciprocated once by the first cam member 78, the first cam member 78 moves forward and the connection sleeve 66 is moved to the first engagement position. 2 When moved beyond the non-engagement position, the second conical outer peripheral contact surface 98b of the second friction engagement member 98 contacts the conical inner peripheral contact surface 54b of the ring gear 54, and the cone of the annular member 94 Since the outer peripheral friction surface 94a presses the conical inner peripheral contact surface 54b of the ring gear 54 via the first friction engagement member 96 and the second friction engagement member 98, the annular member 94 is provided in a relatively non-rotatable manner. In addition, a synchronizing operation is performed in which the rotational speed of the output shaft 62 and the rotational speed of the ring gear 54 are synchronized. When the first cam member 78 moves backward, the second conical outer peripheral contact surface 98b of the second friction engagement member 98 is separated from the conical inner peripheral contact surface 54b of the ring gear 54, so that the synchronous operation is stopped. Be made.

  2, 4, and 5 show that the first cam member 78 is reciprocated once by the actuator 72 being activated and deactivated in the second disengagement position of the connection / disconnection sleeve 66. It is a figure which shows a state when 1 cam member 78 moves forward. As shown in FIGS. 4 and 5, the cam surfaces 78 b and 80 b formed on the first cam member 78 and the second cam member 80, respectively, have a first cam member 78 and a second cam member when the actuator 72 is operated. The first cam member 78 and the second cam in the rotational direction F1 in the rotational direction relative to the second cam member 80, that is, in the rotational direction F1 around the second rotational axis C2 of the first cam member 80 relative to the second cam member 80. The first inclined surfaces 78h and 80c are inclined so that the depth D (see FIG. 5) of the groove of the member 80 becomes deeper, and the grooves of the first cam member 78 and the second cam member 80 toward the rotation direction F1. The second inclined surfaces 78i and 80d are formed adjacent to each other so that the depth D becomes shallower. In the first cam member 78, the angle θ of the first inclined surface 78h with respect to the opposing surface 78a is the same as the angle θ of the second inclined surface 78i with respect to the opposing surface 78a. In the second cam member 80, the angle θ of the first inclined surface 80c with respect to the opposing surface 80a is the same as the angle θ of the second inclined surface 80d with respect to the opposing surface 80a, and the first cam member 78 is opposed to the opposing surface 78a. The angle θ of the first inclined surface 78h is the same as the angle θ of the first inclined surface 80c with respect to the facing surface 80a of the second cam member 80.

  In the four-wheel drive vehicle 10 configured as described above, for example, in a four-wheel drive state in which the first clutch 24 and the second clutch 32 are both engaged, the two-wheel drive travel mode is set by an electronic control unit (not shown). When selected, the connecting / disconnecting sleeve 40 is moved from the first meshing position to the first non-meshing position by the actuator 46, the first clutch 24 is released, and the driving force distribution device 30 for the rear wheels is actuated by the actuator 72. The connecting / disconnecting sleeve 66 is moved from the second meshing position to the second non-meshing position, the second clutch 32 is released, and the driving force is transmitted from the engine 12 only to the front wheels 14L and 14R which are the main driving wheels. It will be in a wheel drive state. Further, the two-wheel drive state in which both the first clutch 24 and the second clutch 32 are released, that is, the power transmission path between the engine 12 and the propeller shaft 28 and the power transmission path between the rear wheel 16 and the propeller shaft 28. When the four-wheel drive travel mode is selected by an electronic control device (not shown) in the disconnected state, the connection sleeve 40 is moved from the first non-engagement position to the first engagement position by the actuator 46. The first clutch 24 is engaged, and after the first clutch 24 is engaged, the connection / disconnection sleeve 66 is moved from the second non-engagement position to the second engagement position by the actuator 72 and the second clutch 32 is engaged. Then, the disconnected state is released.

  In the four-wheel drive vehicle 10, the engagement / disengagement sleeve 66 is moved from the second non-engagement position to the second engagement position by the reciprocating movement of the first cam member 78 in the second clutch 32 after the first clutch 24 is engaged. When the connection sleeve 66 is moved beyond the second non-engagement position by the forward movement of the first cam member 78, the rotational speed of the output shaft 62 is reduced by the synchronization operation of the synchronization device 90. When the first cam member 78 is moved back to engage the outer peripheral connection / disconnection tooth 66a of the connection / disconnection sleeve 66 with the inner peripheral connection / disconnection tooth 54a of the ring gear 54, the synchronizer 90 is turned off. Since the operation is activated, the play from the rear wheels 16L, 16R to the output shaft 62 is clogged, and the output shaft is shuffled by the left and right rear wheels 16L, 16R. Until 62 is driven, the rotational speed of the output shaft 62 is reduced. In the rear wheel driving force distribution device 30, the outer peripheral connection / disconnection tooth 66 a of the connection / disconnection sleeve 66 does not mesh with the inner peripheral connection / disconnection tooth 54 a of the ring gear 54 in a state where the rotational speed of the output shaft 62 is reduced. That is, the backlash from the rear wheels 16L, 16R to the output shaft 62 before the outer peripheral connection / disconnection tooth 66a of the connection / disconnection sleeve 66 meshes with the inner peripheral connection / disconnection tooth 54a of the ring gear 54 after the first cam member 78 is moved backward. So that the rotational speed of the output shaft 62 is restored and the return angle Φ around the second rotational axis C2 of the first cam member 78 relative to the second cam member 80 when the first cam member 78 moves backward (see FIG. 4) (°) is larger than the backlash angle ψ (°) from the rear wheels 16L, 16R to the output shaft 62 (Φ> ψ).

  In the rear wheel driving force distribution device 30, the first cam member 78 is moved when the first cam member 78 is reciprocated and the connection sleeve 66 moves from the second non-engagement position to the second engagement position. The energizing time of the actuator 72 is not shown by an electronic control device (not shown) so that the return angle Φ of the first cam member 78 around the second rotation axis C2 with respect to the second cam member 80 when the actuator moves backward is larger than the backlash angle ψ. Be controlled. Further, the backlash angle Ψ (°) is, for example, from the state in which the torque in the predetermined direction around the second rotation axis C2 is applied to the output shaft 62 in a state where the rotation of the rear wheels 16L and 16R is stopped. The angle measured in advance through experiments or the like in which the output shaft 62 is rotated about the second rotation axis C2 by applying a torque in the direction opposite to the predetermined direction around the second rotation axis C2. However, when measuring the backlash angle ψ (°), the left electronic control coupling 64L and the right electronic control coupling 64R are each in a fully engaged state.

Further, the return angle Φ of the first cam member is set to the first inclined surface of the first cam member 78 and the second cam member 80 with respect to the opposing surfaces 78a and 80a in the ball cam 84, as shown in FIGS. The angle of 78h, 80d is θ (see FIG. 5), and the radius of the circle C passing through the center Ck of the three groove-like cam surfaces 78b, 80b formed in the first cam member 78 and the second cam member 80, respectively. R (see FIG. 4), A (refer to FIG. 2 and FIG. 5) the return amount of the connection sleeve 66 in the direction of the second rotation axis C2 when the first cam member 78 moves backward, and the circumference ratio is π. The return angle Φ is expressed by the following equation (1).
Φ = (A / tan θ) × (180 / (π × R)) (1)

The gravity center Gb of the spherical rolling element 82 shown in FIGS. 4 and 5 is such that the actuator 72 is not operated and the biasing force of the second return spring 86 causes the first inclined surface 78h of the first cam member 78 and the first 2 shows the position of the spherical rolling element 82 when the spherical rolling element 82 is sandwiched between the inclined plane 78i and the first inclined plane 80c and the second inclined plane 80d of the second cam member 80. Also, the center of gravity Gs of the spherical rolling element 82 shown in FIGS. 4 and 5 indicates the position of the spherical rolling element 82 when the actuator 72 is operated and the first cam member 78 moves forward. 4 and FIG. 5, the moving amount B of the spherical rolling element 82 is tangential to the circle C when the first cam member 78 is moved forward by the operation of the actuator 72 as shown in FIG. The amount of movement of the center of gravity of the spherical rolling element 82 in the direction of Lc is shown. However, the center Ck of the cam surface 80b is a contact point of the circle C. In the present embodiment, since the return angle Φ is a relatively small angle, the movement amount B is expressed by the following equation (2).
B = 2πR × (Φ / 360) (2)

  FIG. 6 shows a state in which the first clutch 24 and the second clutch 32 are both engaged from the disconnected state in which the first clutch 24 and the second clutch 32 are both released while the four-wheel drive vehicle 10 is traveling. Until the disconnected state is released, the rotational speed Nwf (rpm) of the front wheels 14L and 14R, the rotational speed Nwr (rpm) of the rear wheels 16L and 16R, the rotational speed Nr (rpm) of the ring gear 54, and the output shaft 62 It is a figure which shows rotational speed No (rpm) of. The rotational speed Nwf of the front wheels 14L, 14R is the average rotational speed of the left and right front wheels 14L, 14R. In FIG. 6, the rotational speed Nwf of the front wheels 14L, 14R is constant. The rotational speed Nwr of the rear wheels 16L and 16R is the average rotational speed of the left and right rear wheels 16L and 16R. In FIG. 6, the rotational speed Nwr of the rear wheels 16L and 16R is constant. However, in the disconnected state, the rotational speed Nwf of the front wheels 14L, 14R is slightly faster than the rotational speed Nwr of the rear wheels 16L, 16R. Further, when the rear wheels 16L and 16R are driven to rotate, the rotational speed No of the output shaft 62 becomes the rotational speed of the rear wheels 16L and 16R due to the drag torque in the pair of left electronic control coupling 64L and right electronic control coupling 64R. It rises to Nwf.

  As shown in FIG. 6, the rotational speed of the ring gear 38 increases and the rotational speed of the propeller shaft 28 increases from the first time point t1 when the synchronization operation is performed by the synchronization device 48, and the input shaft 34 of the input shaft 34 increases at the second time point t2. The rotational speed and the rotational speed of the ring gear 38 are synchronized. When the rotational speed of the ring gear 38 increases, the rotational speed Nr of the ring gear 54 increases via the propeller shaft 28. Next, at the third time point t3 when the connection / disconnection sleeve 40 is switched to the first meshing position, the first clutch 24 is engaged, and the power from the engine 12 is transmitted through the first clutch 24, the propeller shaft 28, and the like to the ring gear 54. Is transmitted to.

  Next, the first cam member 78 moves backward, and the second conical outer peripheral contact surface 98b of the second friction engagement member 98 is separated from the conical inner peripheral contact surface 54b of the ring gear 54 in the synchronization device 90. At time t4, the rotational speed No of the output shaft 62 decreases until the fifth time t5 when the backlash from the rear wheels 16L, 16R to the output shaft 62 is clogged by the driving force transmitted from the rear wheels 16L, 16R to the output shaft 62. After the fifth time point t5, backlash from the rear wheels 16L, 16R to the output shaft 62 is clogged, and the rotational speed No of the output shaft 62 is recovered. Next, at the sixth time point t6 when the connection / disconnection sleeve 66 is switched to the second engagement position, the second clutch 32 is engaged, and the power from the engine 12 is transmitted to the rear wheels 16L, 16R. In the present embodiment, after the backlash from the rear wheels 16L, 16R to the output shaft 62 is clogged and the rotational speed No of the output shaft 62 is recovered, the connection / disconnection sleeve 66 is switched to the second engagement position. That is, the energization time of the actuator 72 is controlled by an electronic control device (not shown) so that the return angle Φ is larger than the backlash angle Ψ (°) (Φ> Ψ). However, for example, if the return angle Φ is controlled to be smaller than the backlash angle Ψ (°), during the period between the fourth time point t4 and the fifth time point t5, that is, when the rotational speed No of the output shaft 62 is decreasing. When the connection / disconnection sleeve 66 is switched to the second engagement position, a relatively large noise is generated from the outer peripheral connection / disconnection tooth 66a of the connection / disconnection sleeve 66 and the inner peripheral connection / disconnection tooth 54a of the ring gear 54.

  As described above, according to the rear wheel driving force distribution device 30 of the present embodiment, the second clutch 32 has the outer peripheral connecting / disconnecting teeth 66 a that can mesh with the inner peripheral connecting / disconnecting teeth 54 a formed on the ring gear 54. And a second meshing position in which the outer peripheral connection / disconnection tooth 66a of the connection / disconnection sleeve 66 is engaged with the inner peripheral connection / disconnection tooth 54a of the ring gear 54. The connection / disconnection sleeve 66 is moved between a second disengagement position where the outer peripheral connection / disconnection tooth 66a of the connection / disconnection sleeve 66 does not mesh with the inner peripheral connection / disconnection tooth 54a of the ring gear 54, and the connection / disconnection sleeve 66 is moved to the second non-engagement position. The first return spring 68 urged from the meshing position toward the second meshing position, the actuator 72, and the output shaft 62 are provided so as to be rotatable relative to the first return spring. A piston 76 that moves the connection / disconnection sleeve 66 to the second non-engagement position against the urging force of the ring 68, and a pair of first cam members 78 that are relatively rotated about the second rotation axis C2 by the operation of the actuator 72. A spherical rolling element 82 sandwiched between groove-shaped cam surfaces 78b and 80b formed on the opposing surfaces 78a and 80a of the pair of first cam member 78 and the pair of first cam member 78 and second cam member 80, respectively. And when the pair of first cam member 78 and second cam member 80 are rotated relative to each other, the first cam member 78 is moved toward the piston 76, the first latching teeth 88a and the second It has a latching tooth 88b, and is provided on the output shaft 62 so as not to rotate relative to the output shaft 62 and to move in the direction of the second rotation axis C2, so that the first latching tooth 88a or the second latching tooth 88b A holder 88 for positioning the connecting / disconnecting sleeve 66 at the second meshing position and the second non-meshing position by latching the stone 76, and the piston 76 is moved by the reciprocating movement of the first cam member 78. The connection / disconnection sleeve 66 is moved between the second non-engagement position and the second engagement position by changing the position at which the piston 76 is latched by 88. When moved beyond the second non-engagement position, a synchronous operation is performed to synchronize the rotational speed of the ring gear 54 and the rotational speed of the output shaft 62, and when the first cam member 78 moves backward. The return angle Φ around the second rotation axis C2 of the first cam member 78 is the backlash angle from the rear wheels 16L, 16R to the output shaft 62. It is greater than. For this reason, even if the first cam member 78 moves backward and the synchronizing device 90 is inactivated and the rotation speed of the output shaft 62 decreases, the outer peripheral connecting / disconnecting teeth 66a of the connecting / disconnecting sleeve 66 are connected to the inner peripheral connection / disconnection of the ring gear 54. Since the backlash from the rear wheels 16L, 16R to the output shaft 62 is packed faster than engaging with the teeth 54a, the outer peripheral connecting / disconnecting teeth 66a of the connecting / disconnecting sleeve 66 is faster than engaging the inner peripheral connecting / disconnecting teeth 54a of the ring gear 54. When the rotational speed of the output shaft 62 is recovered and the difference between the rotational speed of the ring gear 54 and the rotational speed of the output shaft 62 is relatively small, the outer peripheral connecting / disconnecting teeth 66a of the connecting / disconnecting sleeve 66 are connected to the inner peripheral disconnection of the ring gear 54. It meshes with the tooth contact 54a. Thereby, abnormal noise generated from the outer peripheral connection / disconnection tooth 66a of the connection / disconnection sleeve 66 and the inner peripheral connection / disconnection tooth 54a of the ring gear 54 can be suitably suppressed.

  Further, according to the rear wheel driving force distribution device 30 of the present embodiment, the first cam member 78 and the second cam surface 78b are formed on the first cam member 78 and the second cam member 80, respectively. In the rotation direction F1 around the second rotation axis C2 of the first cam member 78 with respect to the second cam member 80 when the cam member 80 is relatively rotated, the depth D of the groove increases toward the rotation direction F1. The first inclined surfaces 78h and 80c that are inclined so as to be adjacent to the second inclined surfaces 78i and 80d that are inclined so that the depth D of the groove becomes shallower toward the rotation direction F1. The angle θ of the first inclined surfaces 78h and 80c of the first cam member 78 and the second cam member 80 with respect to the opposing surfaces 78a and 80a is the same as that of the first cam member 78 and the second cam member 80 with respect to the opposing surfaces 78a and 80a. 2 The angle θ is the same as the angle θ of the slopes 78i, 80d, the return angle is Φ, the angles of the first inclined surfaces 78h, 80c of the first cam member 78 and the second cam member 80 with respect to the opposing surfaces 78a, 80a are θ, the first. The radius of the circle C passing through the center Ck of the three groove-shaped cam surfaces 78b and 80b formed in each of the cam member 78 and the second cam member 80 is R, and the connection and disconnection when the first cam member 78 moves backward. When the return amount of the sleeve 66 in the second rotation axis C2 direction is A and the circumferential ratio is π, the return angle Φ is expressed by the formula Φ = (A / tan θ) × (180 / (π × R)). . For this reason, even if the first cam member 78 moves backward and the synchronizing device 90 is inactivated and the rotation speed of the output shaft 62 decreases, the outer peripheral connecting / disconnecting teeth 66a of the connecting / disconnecting sleeve 66 are connected to the inner peripheral connection / disconnection of the ring gear 54. The backlash from the rear wheels 16L, 16R to the output shaft 62 is filled faster than the teeth 54a are engaged.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, in the above-described embodiment, the holder 88 is formed with the two first engaging teeth 88a and the second engaging teeth 88b. However, even if three or more engaging teeth are formed, for example. good.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

16L, 16R: Rear wheels (drive wheels)
30: Rear wheel driving force distribution device (vehicle driving force distribution device)
32: Second clutch (connecting / disconnecting device)
54: Ring gear 54a: Inner peripheral connection / disconnection tooth (first connection / disconnection tooth)
62: Output shaft 64L: Left electronic control coupling (electronic control coupling)
64R: Right electronic control coupling (electronic control coupling)
66: Connection / disconnection sleeve 66a: Peripheral connection / disconnection tooth (second connection / disconnection tooth)
68: First return spring (return spring)
72: Actuator 76: Piston 78: First cam member (cam member)
78a: opposing surface 78b: cam surface 80: second cam member (cam member)
80a: Opposing surface 80b: Cam surface 82: Spherical rolling element 84: Ball cam 88: Holder 88a: First latching tooth (latching tooth)
88b: Second hook teeth (hook teeth)
90: Synchronizer C2: Second rotation axis (rotation axis)
Φ: Return angle Ψ: Backlash angle

Claims (1)

A ring gear, an output shaft, a pair of electronically controlled couplings that transmit torque output from the output shaft to each of a pair of drive wheels, and a connection that connects and disconnects a power transmission path between the ring gear and the output shaft. And a synchronizing device that synchronizes the rotation of the ring gear and the rotation of the output shaft, and the driving force transmitted to the ring gear is transmitted to the pair of driving wheels via the pair of electronically controlled couplings, respectively. A vehicle driving force distribution device that distributes,
The connecting / disconnecting device is:
A second connecting / disconnecting tooth capable of meshing with a first connecting / disconnecting tooth formed on the ring gear; provided on the output shaft so as not to be relatively rotatable and movable in a direction of a rotation axis; A connection sleeve that is moved between an engagement position that meshes with the first connection / disconnection tooth and a non-engagement position at which the second connection / disconnection tooth does not mesh with the first connection / disconnection tooth;
A return spring that urges the connection / disconnection sleeve from the non-engagement position toward the engagement position;
An actuator,
A piston that is provided so as to be relatively rotatable with respect to the output shaft, and that moves the connection sleeve to the non-engagement position against the biasing force of the return spring;
A pair of cam members that are relatively rotated around the rotation axis by the operation of the actuator, and a spherical rolling element sandwiched between groove-shaped cam surfaces formed on opposite surfaces of the pair of cam members, A ball cam in which one of the pair of cam members is moved toward the piston when the pair of cam members are relatively rotated;
A plurality of stages of latching teeth, provided on the output shaft so as not to rotate relative to the output shaft and immovable in the direction of the rotation axis; A holder for positioning a sleeve in the meshing position and the non-meshing position,
The piston is moved by one reciprocating movement of the pair of cam members, and the connection sleeve is moved between the non-engagement position and the engagement position by changing the position where the piston is latched by the holder. And
The synchronization device is configured such that when the connection / disconnection sleeve is moved beyond the non-engagement position, a synchronization operation is performed to synchronize the rotation of the ring gear and the rotation of the output shaft,
A return angle of the one cam member around the rotation axis when one of the pair of cam members moves backward is larger than a backlash angle from the drive wheel to the output shaft. Vehicle driving force distribution device.

Images