JP2013108613A - Clutch, and four-wheel drive vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clutch capable of reducing size, weight and cost by providing, with a simple structure, a mechanism transmitting rotary torque from an input rotary member to an output rotary member without transmitting the rotary torque in a direction opposite thereto, and a four-wheel drive vehicle using the same.SOLUTION: In this clutch 3 including an input rotary member 31, an output rotary member 33 relatively rotatable coaxially with the input rotary member 31, and an intermediate rotary member 32 interposed between the input rotary member and the output rotary member, and transmitting torque to the output rotary member 33 from the input rotary member 31 without transmitting the torque from the output rotary member 33 to the input rotary member 31, relative rotation of the intermediate rotary member 32 with the input rotary member 31 is limited in a predetermined range, and the intermediate rotary member 32 is axially moved by the relative rotation with the input rotary member 31 and frictionally contacts the output rotary member 33.

Description

  The present invention relates to a clutch and a four-wheel drive vehicle, and in particular, a clutch that transmits rotational torque from an input rotary member to an output rotary member and does not transmit rotational torque in the opposite direction, and a four-wheel drive vehicle using the clutch. About.

  Conventionally, a clutch is provided on the drive source side and the wheel side of the propeller shaft that transmits the driving force in the longitudinal direction of the vehicle, and in the two-wheel drive that transmits the driving force only to the front wheels, both clutches are not in torque transmission state. Thus, there is known a four-wheel drive vehicle capable of improving the fuel consumption by stopping the rotation of the propeller shaft and reducing the power loss (see Patent Document 1).

  The four-wheel drive vehicle described in Patent Document 1 is provided with a multi-plate clutch between an engine and a propeller shaft arranged on the front side of the vehicle, and a hub clutch device between a rear wheel axle and a wheel hub. The hub clutch device is configured so that the rear wheel axle and the wheel hub can be remotely connected and disconnected. The hub clutch device includes a sprag type one-way clutch. The one-way clutch includes an inner ring coupled to a wheel hub, an outer ring that can be coupled to a rear axle, and a plurality of sprags disposed between the inner ring and the outer ring, and the rotation of the outer ring causes the rotation of the inner ring. When it exceeds, the sprag tilts and transmits torque, and when the rotation of the inner ring exceeds the rotation of the outer ring, it is configured to be in a free running state where torque transmission is not performed between the inner ring and the outer ring. Yes.

  A slider capable of coupling the outer wheel and the rear wheel axle is disposed between the outer wheel and the rear wheel axle. The slider moves in the axial direction by switching the flow path of the pressure fluid by remote operation. When the slider moves to one side in the axial direction, the outer ring and the rear wheel axle are coupled, and when moved to the other side in the axial direction, the outer ring And the rear wheel axle are separated. In a state where the outer wheel and the rear wheel axle are separated from each other, torque transmission between the rear wheel axle and the wheel hub is not performed regardless of the magnitude relationship between the rotation of the inner wheel and the rotation of the outer wheel.

JP-A-9-169223

  A wheel hub described in Patent Literature 1 includes a plurality of sprags, a pair of retainers that retain the plurality of sprags, and a one-way clutch that includes a spring disposed between the pair of retainers, and a slider And a mechanism for moving the slider, the number of parts is large and the structure is complicated. For this reason, there has been a structural restriction on size reduction, weight reduction, and cost reduction.

  Therefore, the present invention realizes a mechanism that transmits rotational torque from the input rotating member to the output rotating member and does not transmit the rotating torque in the opposite direction, with a simple configuration, thereby achieving a reduction in size and weight and cost. It is an object of the present invention to provide a clutch that can be used, and a four-wheel drive vehicle using the clutch.

  In order to achieve the above object, the present invention provides a clutch and a four-wheel drive vehicle according to [1] to [7].

[1] An input rotation member, an output rotation member that can be relatively rotated coaxially with the input rotation member, and an intermediate rotation member interposed between the input rotation member and the output rotation member, and the input rotation A clutch that transmits torque from a member to the output rotating member and does not transmit torque from the output rotating member to the input rotating member, wherein the intermediate rotating member has a predetermined relative rotation with the input rotating member. A clutch which is limited to a range and moves in the axial direction by relative rotation with the input rotation member and frictionally contacts the output rotation member.

[2] A housing that is a non-rotating member that accommodates the intermediate rotating member, and is interposed between the housing and the intermediate rotating member, and biases the intermediate rotating member in the axial direction toward the input rotating member. The clutch according to [1], further including an urging member.

[3] The intermediate rotating member includes a cam portion that generates an axial thrust force by relative rotation with the input rotating member, and a disk-shaped flange portion formed on the outer peripheral side of the cam portion. The clutch according to [2], wherein the housing has an annular recess that accommodates at least a part of the flange portion, and the biasing member is accommodated in the annular recess of the housing.

[4] A driving source that generates a driving force for driving the front wheels and the rear wheels of the vehicle, and a driving force that is constantly transmitted to a main driving wheel that is one of the front wheels and the rear wheels, and the other of the front wheels and the rear wheels. A driving force transmission system that transmits the driving force to the auxiliary driving wheel according to a vehicle running state, the driving force transmission system comprising: a first differential gear device on the main driving wheel side; and a propeller shaft. A first clutch that transmits a driving force to the propeller shaft, a second clutch that transmits a driving force transmitted through the propeller shaft to the auxiliary driving wheel side, and a first clutch on the auxiliary driving wheel side. The first clutch is a multi-plate clutch capable of adjusting a driving force transmitted to the propeller shaft, and the second clutch is an input rotation on the propeller shaft side. Member and said input rotation member An output rotation member on the side of the auxiliary drive wheel that can be relatively rotated on the same axis, and an intermediate rotation member interposed between the input rotation member and the output rotation member, from the input rotation member to the output rotation member Is a clutch that transmits rotational torque and does not transmit torque from the output rotating member to the input rotating member. The intermediate rotating member is limited in relative rotation with the input rotating member to a predetermined range, and A four-wheel drive vehicle that moves in an axial direction by relative rotation with a rotating member and frictionally contacts the output rotating member.

[5] In the propeller shaft and the first and second differential gear devices, the rotation member on the drive source side of the first clutch is more than the rotation member on the propeller shaft side of the first clutch. The four-wheel drive vehicle according to [4], wherein the four-wheel drive vehicle is connected by a gear mechanism in which a gear ratio is set so as to rotate quickly.

[6] In the above [4] or [5], the second clutch is provided between the second differential gear device and a left rear wheel and a right rear wheel as the auxiliary driving wheels, respectively. The described four-wheel drive vehicle.

[7] The four-wheel drive vehicle according to [4] or [5], wherein the second clutch is provided between the propeller shaft and the second differential gear device.

  According to the present invention, a mechanism that transmits rotational torque from an input rotational member to an output rotational member and does not transmit rotational torque in the opposite direction is realized with a simple configuration, thereby achieving a reduction in size, weight, and cost. It becomes possible.

It is the schematic which shows the structural example of the four-wheel drive vehicle which concerns on embodiment of this invention. (A) is sectional drawing which shows the structural example of the clutch which concerns on embodiment of this invention. (B) is sectional drawing which cut | disconnected the cam part of the input rotation member and the intermediate | middle rotation member along the circumferential direction. (A) is sectional drawing which shows the structural example of the clutch in a torque transmission state. (B) is sectional drawing which cut | disconnected the cam part of the input rotation member in the torque transmission state, and the intermediate rotation member along the circumferential direction. It is the schematic which shows the structural example of the four-wheel drive vehicle which concerns on the modification of this invention.

[Embodiment]
FIG. 1 is a schematic diagram showing a configuration example of a four-wheel drive vehicle according to an embodiment of the present invention. As shown in FIG. 1, the four-wheel drive vehicle 100 includes an engine 101 as a drive source, a torque converter 102 connected to the output shaft of the engine 101, and the driving force of the engine 101 transmitted by the torque converter 102. A transmission 103 that changes speed, a pair of left and right front wheels 104 (left front wheel 104L and right front wheel 104R) and a pair of left and right rear wheels that can switch the driving force of the engine 101 that is changed by the transmission 103 between a two-wheel drive state and a four-wheel drive state. A driving force transmission system 109 that transmits to the wheels 105 (the left rear wheel 105L and the right rear wheel 105R) is provided.

  In the present embodiment, the front wheels 104 are used as main driving wheels to which the driving force of the engine 101 is constantly transmitted, and the rear wheels 105 are used as auxiliary driving wheels to which the driving force of the engine 101 is transmitted according to the vehicle running state. Each function. Here, the vehicle running state includes, for example, the difference between the rotational speed of the front wheel 104 and the rotational speed of the rear wheel 105, the amount of depression of the accelerator pedal (accelerator opening) by the driver's operation, the steering angle, and the like. .

(Configuration of driving force transmission system 109)
The driving force transmission system 109 transmits the driving force of the engine 101 to the first differential gear device 11 on the front wheel 104 side, the second differential gear device 12 on the rear wheel 105 side, and the first differential gear device 11. And the second differential gear device 12, which transmits the driving force of the engine 101 in the front-rear direction of the four-wheel drive vehicle 100, and the first differential gear device 11 and the propeller shaft 13. And a driving force transmission device 2 provided between the two.

  The driving force transmission system 109 further includes a pair of drive shafts 11L and 11R provided between the first differential gear device 11, the left front wheel 104L and the right front wheel 104R, and the second differential gear device 12. Drive shafts 12L, 12R respectively connected to the pair of side gears 123, a pair of clutches 3 provided between the drive shaft 12L and the left rear wheel 105L, and between the drive shaft 12R and the right rear wheel 105R. And have.

  The first differential gear device 11 is a differential device that transmits driving force to the left front wheel 104L and the right front wheel 104R while allowing the differential between the left front wheel 104L and the right front wheel 104R. A fixed pinion shaft 111, a pair of pinion gears 112 pivotally supported on the pinion shaft 111, a pair of side gears 113 meshed with the pair of pinion gears 112 with the gear shaft orthogonal thereto, and a ring gear fixed to the outer peripheral surface of the differential case 110 114.

  Drive shafts 11L and 11R are coupled to the pair of side gears 113, respectively. Further, the driving force of the engine 101 shifted by the transmission 103 is transmitted to the ring gear 114 by the speed reduction mechanism 106.

  The driving force transmission device 2 includes an inner rotating member 21 that is connected to the differential case 110 so as not to rotate relative to the differential case 110, a bottomed cylindrical outer rotating member 22 that houses the inner rotating member 21, and an outer peripheral surface and an outer surface of the inner rotating member 21. And a main clutch 23 including a plurality of friction plates disposed between the rotating member 22 and the main clutch 23. Details of the configuration of the driving force transmission device 2 will be described later.

  A gear 221 is fixed to one end of the outer rotating member 22 (the end opposite to the electromagnetic coil 24) so as not to be relatively rotatable. The gear 221 meshes with a gear 131 fixed to one end of the propeller shaft 13 on the front wheel 104 side. The gear 221 and the gear 131 are both bevel gears, and mesh with each other with their gear axes orthogonal to each other. The gear 221 and the gear 131 constitute a gear mechanism 107.

  The second differential gear device 12 is a differential device that transmits a driving force to the left rear wheel 105L and the right rear wheel 105R while allowing a differential between the left rear wheel 105L and the right rear wheel 105R. A pair of pinion shafts 121 fixed to the differential case 120, a pair of pinion gears 122 pivotally supported by the pinion shaft 121, a pair of side gears 123 that mesh with the pair of pinion gears 122 at right angles, and an outer peripheral surface of the differential case 120. And a fixed ring gear 124.

  The ring gear 124 meshes with a gear 132 fixed to one end on the rear wheel 105 side of the propeller shaft 13. The ring gear 124 and the gear 132 are both bevel gears, and mesh with each other with their gear axes orthogonal to each other. The ring gear 124 and the gear 132 constitute the gear mechanism 108.

  In the present embodiment, the gear ratio of the gear mechanism 107 including the gear 221 and the gear 131 (the number of teeth of the gear 221 / the number of teeth of the gear 131) is equal to the gear of the gear mechanism 108 including the ring gear 124 and the gear 132. It is set smaller than the ratio (number of teeth of ring gear 124 / number of teeth of gear 132). That is, the gear ratio of the gear mechanism 107 and the gear mechanism 108 is such that the gear 221 rotates faster than the ring gear 124 when the propeller shaft 13 is rotated with the front wheel 104 and the rear wheel 105 being freely rotatable. Is set. Such setting of the gear ratio can be realized, for example, by making the pitch circle diameter of the gear 131 and the gear 132 common and making the pitch circle diameter of the gear 221 smaller than the pitch circle diameter of the ring gear 124.

(Configuration of the driving force transmission device 2)
The main clutch 23 of the driving force transmission device 2 includes a plurality of inner clutch plates 23a that are spline-fitted to the inner rotating member 21 and a plurality of outer members that are spline-fitted to the outer rotating member 22 to be relatively non-rotatable. The clutch plates 23b are alternately arranged. Between the inner rotating member 21 and the outer rotating member 22, lubricating oil (not shown) that lubricates frictional sliding between the inner clutch plate 23a and the outer clutch plate 23b and suppresses wear is interposed. The main clutch 23 is an example of a multi-plate clutch according to the present invention.

  Further, between the inner rotating member 21 and the outer rotating member 22, an annular electromagnetic coil 24 for generating a pressing force for pressing the main clutch 23 in the axial direction, and a pilot pressed by the electromagnetic force of the electromagnetic coil 24. A cam mechanism 26 that converts the rotational force transmitted through the clutch 25 and the pilot clutch 25 into an axial thrust force that presses the main clutch 23 is disposed.

  The cam mechanism 26 includes a pilot cam 261, a main cam 262, and a plurality of cam balls 263. The main cam 262 is spline-fitted to the inner rotating member 21 so as not to rotate relative to the inner rotating member 21 and to be movable in the axial direction. The plurality of cam balls 263 roll the plurality of cam grooves formed on the opposing surfaces of the pilot cam 261 and the main cam 262, respectively, so that the main cam 262 is pilot-camera according to the relative rotation between the pilot cam 261 and the main cam 262. Thrust force is generated by separating from 261 in the axial direction.

  An excitation current is supplied to the electromagnetic coil 24 from a control device (not shown) according to the vehicle running state. When an excitation current is supplied to the electromagnetic coil 24, the pilot clutch 25 is pressed by the electromagnetic force, and the relative rotation between the pilot cam 261 and the outer rotating member 22 is suppressed, whereby the pilot cam 261 and the main cam 262 are relatively moved. The main cam 262 presses the inner clutch plate 23a and the outer clutch plate 23b of the main clutch 23 in the axial direction to make frictional contact. Since the relative rotation angle between the pilot cam 261 and the main cam 262 changes according to the transmission torque of the pilot clutch 25, that is, the exciting current supplied to the electromagnetic coil 24, between the inner rotating member 21 and the outer rotating member 22. The transmitted driving force can be adjusted by increasing or decreasing the excitation current supplied to the electromagnetic coil 24.

(Configuration of clutch 3)
FIG. 2A is a cross-sectional view illustrating a configuration example of the clutch 3. The clutch 3 includes a housing 30 that is a non-rotating member fixed to the vehicle body, an input rotating member 31, an output rotating member 33 that is coaxially rotatable with the input rotating member 31, and an input rotating member 31 and an output rotating member. An intermediate rotating member 32 interposed between the member 33, a plurality of rolling elements 34 interposed between the input rotating member 31 and the intermediate rotating member 32, and a first interposed between the housing 30 and the intermediate rotating member 32. 1 and second disc springs 351, 352.

  The input rotation member 31 is connected to the drive shaft 12L (or the drive shaft 12R) so as not to be relatively rotatable. The output rotation member 33 is connected to a hub unit (not shown) of the left rear wheel 105L (or right rear wheel 105R), and transmits driving force to the left rear wheel 105L (or right rear wheel 105R).

  The housing 30 includes a first housing member 301 and a second housing member 302, and the first housing member 301 and the second housing member 302 are fixed to each other by bolts 303, for example. An annular recess 30 a is formed on the inner surface of the housing 30 between the first housing member 301 and the second housing member 302. The annular recess 30 a is formed as an annular groove having an opening inside the housing 30. First and second disc springs 351 and 352 are accommodated in the annular recess 30a.

  Further, the housing 30 has an accommodation space 30b for accommodating one end portions of the input rotation member 31 and the output rotation member 33 and the intermediate rotation member 32, and an insertion hole 30c through which the shaft portion 331 of the output rotation member 33 is inserted is first. Insertion holes 30 d through which the shaft portion 311 of the input rotation member 31 is inserted are formed in the first housing member 301, respectively, in the second housing member 302. A needle bearing 361 is provided between the wall 301a of the first housing member 301 in which the insertion hole 30c is formed and the output rotating member 33, and the wall 302a of the second housing member 302 in which the insertion hole 30d is formed. Needle bearings 362 are disposed between the input rotation member 31 and the input rotation member 31, respectively.

  The input rotation member 31 includes a cylindrical shaft portion 311 and a cam portion 312 that is formed to protrude to the outer peripheral side of the shaft portion 311 and rotates integrally with the shaft portion 311. The shaft portion 311 and the cam portion 312 are coupled by welding, for example. A spline fitting portion 311a into which one end portion of the drive shaft 12L (or drive shaft 12R) is fitted is formed on the inner surface of the shaft portion 311. The cam portion 312 has an annular plate shape, and a needle bearing 362 abuts on one surface of the second housing member 302 facing the wall portion 302a, thereby restricting the axial movement of the input rotating member 31. A plurality of (for example, six) cam grooves 312a are formed on the surface of the cam portion 312 opposite to the surface that contacts the needle bearing 362.

  The intermediate rotation member 32 is formed with a through hole 32a through which the shaft portion 311 of the input rotation member 31 is inserted at the center. The intermediate rotation member 32 has a cam portion 321 formed on the outer periphery of the through hole 32a, and a disk-shaped flange portion 322 formed on the outer peripheral side of the cam portion 321 and rotating integrally with the cam portion 321. ing. In the cam portion 321, a plurality of cam grooves 321 a equal in number to the cam grooves 312 a are formed in the axial direction so as to face the plurality of cam grooves 312 a formed in the cam portion 312 of the input rotation member 31.

  The outer peripheral end of the flange portion 322 is accommodated in the annular recess 30 a of the housing 30. The flange portion 322 is urged (pressed) in the axial direction toward the cam portion 312 of the input rotation member 31 by a first disc spring 351 disposed between the flange portion 322 and the first housing member 301. The flange portion 322 is urged in the axial direction toward the output rotation member 33 by a second disc spring 352 disposed between the flange portion 322 and the second housing member 302. The intermediate rotating member 32 receives a resistance force when rotating with respect to the housing 30 due to the contact between the flange portion 322 and the first disc spring 351 and the second disc spring 352.

  In the present embodiment, the axial thickness of the cam portion 321 of the intermediate rotating member 32 is formed to be thicker than the axial thickness of the flange portion 322. However, the thickness of the cam part 321 and the thickness of the flange part 322 may be the same.

  The output rotating member 33 includes a shaft-shaped shaft portion 331, a disc portion 332 that is provided at one end of the shaft portion 331 and has a larger diameter than the shaft portion 331, and an end portion on the outer peripheral side of the disc portion 332. And a cylindrical protruding portion 333 formed so as to protrude in the axial direction from the intermediate rotating member 32 to the intermediate rotating member 32. The needle bearing 361 is in contact with one surface of the disk portion 332 (the surface facing the wall portion 301a of the first housing member 301), and the axial movement of the output rotation member 33 is restricted. The protruding portion 333 is formed on the surface opposite to the surface facing the wall portion 301a of the disc portion 332. An axial end surface 333 a at the tip of the protruding portion 333 faces the flange portion 322. The region facing the axial end surface 333a of the flange portion 322 is formed as a contact surface 322a that frictionally contacts the axial end surface 333a in a torque transmission state of the clutch 3 described later.

  FIG. 2B is a cross-sectional view of the cam portion 312 of the input rotation member 31 and the cam portion 321 of the intermediate rotation member 32 cut along the circumferential direction. The cam groove 312a formed in the cam portion 312 extends along the circumferential direction, is deepest at the center portion, and is formed so as to gradually become shallower as it approaches the end portion. Similarly, the cam groove 321a formed in the cam portion 321 is formed so as to extend along the circumferential direction, deepest at the center portion thereof, and gradually become shallower as approaching the end portion. A rolling element 34 is interposed between the cam groove 312a and the cam groove 321a. In the present embodiment, the rolling elements 34 are formed as spherical cam balls.

(Operation of clutch 3)
Next, the operation of the clutch 3 will be described.

  FIG. 3A is a cross-sectional view in a torque transmission state in which the clutch 3 transmits rotational torque from the input rotation member 31 to the output rotation member 33. FIG. 3B is a cross-sectional view of the cam portion 312 of the input rotation member 31 and the cam portion 321 of the intermediate rotation member 32 in the state shown in FIG.

  When the driving force is transmitted to the second differential gear device 12 via the driving force transmission device 2 and the propeller shaft 13, and the input rotation member 31 of the clutch 3 receives the driving force from the drive shaft 12L (or the drive shaft 12R). When the flange portion 322 of the intermediate rotating member 32 receives the rotational resistance force from the first disc spring 351 and the second disc spring 352, relative rotation occurs between the input rotating member 31 and the intermediate rotating member 32. . As shown in FIG. 3B, the relative rotation is limited to an angular range in which the rolling element 34 rolls on the cam groove 312a and the cam groove 321a.

  When the rolling element 34 rolls along the cam groove 312a and the cam groove 321a due to the relative rotation between the input rotating member 31 and the intermediate rotating member 32, the rolling element 34 moves to a shallow portion of the cam groove 312a and the cam groove 321a. The intermediate rotation member 32 is separated from the input rotation member 31 in the axial direction. Due to the axial movement of the intermediate rotating member 32, the contact surface 322 a of the flange portion 322 is brought into frictional contact with the axial end surface 333 a of the protruding portion 333 of the output rotating member 33. Torque is transmitted from the intermediate rotating member 32 to the output rotating member 33 by frictional contact between the contact surface 322a and the axial end surface 333a. Further, when the contact surface 322a and the axial end surface 333a come into contact with each other, the intermediate rotating member 32 is no longer separated from the input rotating member 31, so that the rolling of the rolling element 34 within the cam groove 312a and the cam groove 321a is stopped. .

  Thus, torque (driving force distributed to the drive shaft 12L by the second differential gear device 12) is transmitted to the left rear wheel 105L by the clutch 3 connected to the drive shaft 12L, and is connected to the drive shaft 12R. Torque (the driving force distributed to the drive shaft 12R by the second differential gear unit 12) is transmitted to the right rear wheel 105R by the clutch 3.

  On the other hand, when transmission of the driving force by the driving force transmission device 2 is interrupted while the four-wheel drive vehicle 100 is traveling, torque is not input from the drive shaft 12L (or the drive shaft 12R) to the input rotation member 31 of the clutch 3. Therefore, the force for relatively rotating the input rotating member 31 and the intermediate rotating member 32 is weakened, and the intermediate rotating member 32 is pushed back by the first disc spring 351. Then, the frictional contact between the contact surface 322a of the intermediate rotation member 32 and the axial end surface 333a of the output rotation member 33 is released, and torque transmission via the clutch 3 is not performed.

  Even in this state, the rear wheel 105 (the left rear wheel 105L and the right rear wheel 105R) rotates as the four-wheel drive vehicle 100 travels, and the output rotating member 33 rotates as the rear wheel 105 rotates. Since the member 33 and the intermediate rotation member 32 are separated from each other, torque is not transmitted from the output rotation member 33 to the intermediate rotation member 32 and the input rotation member 31.

  Thus, the propeller shaft 13, the second differential gear device 12, and the drive shafts 12L and 12R are connected to the torque transmission upstream side (engine engine) in the driving force transmission system 109 even when the four-wheel drive vehicle 100 is traveling. Since no torque is transmitted from the torque transmission downstream side (the rear wheel 105 side), the rotation is stopped. Thereby, for example, the rotational resistance due to the stirring of the differential oil by the ring gear 124 does not occur, so the fuel efficiency of the four-wheel drive vehicle 100 is improved.

  In the present embodiment, as described above, the gear ratio of the gear mechanism 107 including the gear 221 and the gear 131 is set smaller than the gear ratio of the gear mechanism 108 including the ring gear 124 and the gear 132. Therefore, the output rotating member 33 does not rotate faster than the input rotating member 31 during traveling in the four-wheel drive state in which the driving force transmission device 2 transmits the driving force, and the left rear wheel 105L and the right rear wheel 105R do not rotate. The state where the driving force is transmitted is maintained.

  Here, when the four-wheel drive vehicle 100 travels straight, the front wheel 104 and the rear wheel 105 rotate at the same speed, so the differential case 110 of the first differential gear device 11 and the differential case 120 of the second differential gear device 12. And the differential rotation between the gear 221 and the differential case 110 due to the difference between the gear ratio of the gear mechanism 107 and the gear ratio of the gear mechanism 108 is a slip between the inner clutch plate 23a and the outer clutch plate 23b. Absorbed. That is, the gear ratio between the gear mechanism 107 and the gear mechanism 108 is set so that the inner rotating member 21 rotates faster than the outer rotating member 22 when the four-wheel drive vehicle 100 travels straight. Thus, driving force is transmitted to the front wheels 104 and the rear wheels 105 during traveling in the four-wheel drive state.

(Effect of embodiment)
According to the clutch 3 and the four-wheel drive vehicle 100 according to the embodiment described above, the following effects can be obtained.

(1) Since the clutch 3 is configured to switch between the torque transmission state and the torque transmission cutoff state by moving the intermediate rotation member 32, whose relative rotation with the input rotation member 31 is restricted, in the axial direction, For example, compared with a sprag type one-way clutch, the structure can be simplified and the number of parts can be reduced. As a result, the size and weight can be reduced, and further, the number of assembling steps can be reduced and the cost can be reduced.

(2) In the clutch 3, when no torque is transmitted from the output rotation member 33 to the input rotation member 31, and only the output rotation member 33 rotates, the output rotation member 33 is not the intermediate rotation member 32 or the like. Therefore, the drag torque can be reduced. Thereby, the fuel consumption of the four-wheel drive vehicle 100 can be further improved.

(3) Since the intermediate rotating member 32 receives a biasing force from the first disc spring 351 toward the cam portion 312 of the input rotating member 31, the intermediate rotating member 32 and the output in the state where no torque is input to the input rotating member 31. The rotating member 33 can be reliably separated from the rotating member 33 and the rolling element 34 can be stably held at the position shown in FIG. Thereby, abnormal noise caused by a collision between members due to vibration or the like of the four-wheel drive vehicle 100 in the torque transmission cut-off state can be suppressed, and when the torque is input to the input rotating member 31, the rolling element 34 smoothly cams. The grooves 312a and 321a can roll to shift to a torque transmission state.

(4) The intermediate rotating member 32 has a part of the flange portion 322 accommodated in the annular recess 30a of the housing 30, and receives a biasing force from the first and second disc springs 351 and 352 accommodated in the annular recess 30a. Thus, the structure for holding the first and second disc springs 351 and 352 and the structure for biasing the intermediate rotating member 32 by the first and second disc springs 351 and 352 are simply realized. it can. Further, when the clutch 3 is assembled, the needle bearing 361, the output rotating member 33, the first disc spring 351, the intermediate rotating member 32, the second disc spring 352, the rolling element 34, and the input rotation are placed in the first housing member 301. Since the member 31 and the needle bearing 362 may be sequentially accommodated to fix the second housing member 302, the assembly can be easily performed.

(5) Since the four-wheel drive state and the two-wheel drive state of the four-wheel drive vehicle 100 can be switched only by the control of the driving force transmission device 2, the switching between the four-wheel drive state and the two-wheel drive state is promptly performed. Can do. Further, since the driving force transmission device 2 can adjust the driving force transmitted to the propeller shaft 13, the driving force transmitted to the propeller shaft 13 gradually increases from the two-wheel driving state in which the rotation of the propeller shaft 13 is stopped. If controlled to do so, the impact at the time of transition from the two-wheel drive state to the four-wheel drive state can be mitigated.

(6) The gear ratio between the gear mechanism 107 and the gear mechanism 108 is set so that the inner rotating member 21 rotates faster than the outer rotating member 22 when the four-wheel drive vehicle 100 travels straight ahead. When traveling in this state, the driving force is always transmitted to the rear wheel 105 via the clutch 3. That is, for example, if the gear ratio of the gear mechanism 107 and the gear mechanism 108 is set so that the inner rotating member 21 and the outer rotating member 22 rotate at the same speed, the output is caused by some factor when the four-wheel drive vehicle 100 travels straight ahead. Although torque transmission by the clutch 3 is not performed when the rotation member 33 exceeds the rotation speed of the input rotation member 31, according to the present embodiment, such a phenomenon can be avoided.

(7) Since the clutch 3 is provided between the second differential gear device 12 and the left rear wheel 105L and the right rear wheel 105R, not only the propeller shaft 13 but also when traveling in a two-wheel drive state. The rotation of the differential case 120 and the ring gear 124 of the second differential gear device 12 can be stopped. Thereby, the rotational resistance due to the stirring of the differential oil by the ring gear 124 can be reduced, and the fuel efficiency of the four-wheel drive vehicle 100 can be improved.

[Other embodiments]
Although the clutch and the four-wheel drive vehicle of the present invention have been described based on the above embodiment, the present invention is not limited to this embodiment, and can be implemented in various modes without departing from the scope of the present invention. Is possible.

  For example, in the above embodiment, the case where the two clutches 3 are respectively provided between the second differential gear device 12 and the left rear wheel 105L and the right rear wheel 105R has been described. As shown in FIG. 4, one clutch 3 may be provided between the propeller shaft 13 and the second differential gear device 12. In this case, the propeller shaft 13 is connected to the input rotating member 31, and the drive shaft having a gear 132 provided at one end is connected to the output rotating member 33. Even in this configuration, the effects (1) to (6) described in the above embodiment can be obtained. Further, the number of clutches 3 can be reduced.

  Moreover, although the said embodiment demonstrated the case where the clutch 3 was applied to the four-wheel drive vehicle 100, the use of the clutch 3 is not restricted to this, It applies to vehicles of another structure, and transport machines other than a vehicle. It is also possible. Further, the clutch 3 can be used for products other than transport machines such as machine tools.

  In the above embodiment, the case where the disc spring is applied as the biasing member that biases the intermediate rotating member 32 has been described. However, the present invention is not limited to this, and an elastic body such as a coil spring, a wave washer, or rubber is biased. You may apply as a member. Further, the second disc spring 352 may be omitted, and the clutch 3 may be configured so that the flange portion 322 of the intermediate rotation member 32 is brought into contact with the second housing member 302 by the biasing force of the first disc spring 351. .

  Moreover, although the said embodiment demonstrated the case where the mechanism which moves the intermediate | middle rotation member 32 to an axial direction by relative rotation with the input rotation member 31 was embodied by rolling of the rolling element 34 in cam surface 312a, 321a. However, the present invention is not limited to this. For example, the cam portion 312 and the cam portion 321 may be embodied by sliding between inclined surfaces (inclined surfaces with respect to the circumferential direction).

2 ... Driving force transmission device, 3 ... Clutch, 11 ... Differential gear device, 11L, 11R ... Drive shaft, 12 ... Differential gear device, 12L, 12R ... Drive shaft, 13 ... Propeller shaft, 21 ... Inner rotating member, 22 ... Outer rotating member, 23 ... Main clutch, 23a ... Inner clutch plate, 23b ... Outer clutch plate, 24 ... Electromagnetic coil, 25 ... Pilot clutch, 26 ... Cam mechanism, 30 ... Housing, 30a ... Annular recess, 30b ... Housed Space, 30c, 30d ... insertion hole, 31 ... input rotation member, 32 ... intermediate rotation member, 32a ... through hole, 33 ... output rotation member, 34 ... rolling element, 100 ... four-wheel drive vehicle, 101 ... engine, 102 ... Torque converter, 103 ... transmission, 104 ... front wheel, 104L ... left front wheel, 104R ... right front wheel, 10 ... rear wheel, 105L ... left rear wheel, 105R ... right rear wheel, 106 ... deceleration mechanism, 107, 108 ... gear mechanism, 109 ... driving force transmission system, 110 ... differential case, 111 ... pinion shaft, 112 ... pinion gear, 113 ... Side gear, 114 ... ring gear, 120 ... differential case, 121 ... pinion shaft, 122 ... pinion gear, 123 ... side gear, 124 ... ring gear, 131, 132 ... gear, 221 ... gear, 261 ... pilot cam, 262 ... main cam, 263 ... cam ball, 301 ... 1st housing member, 301a ... Wall part, 302 ... 2nd housing member, 302a ... Wall part, 303 ... Bolt, 311 ... Shaft part, 311a ... Spline fitting part, 312, 321 ... Cam part, 312a, 321a ... Cam groove, 322 ... Flange, 322a ... Contact surface, 3 1 ... shaft portion, 332 ... disc part, 333 ... protrusions, 333a ... axial end face, 351 ... first disc spring, 352 ... second disc spring, 361, 362 ... needle bearing

Claims (7)

An input rotating member, an output rotating member that is relatively rotatable coaxially with the input rotating member, and an intermediate rotating member that is interposed between the input rotating member and the output rotating member. A clutch that transmits torque to the output rotating member and does not transmit torque from the output rotating member to the input rotating member;
The intermediate rotation member has a relative rotation with the input rotation member limited to a predetermined range, and moves in the axial direction by the relative rotation with the input rotation member to make frictional contact with the output rotation member. A housing that is a non-rotating member that houses the intermediate rotating member;
A biasing member interposed between the housing and the intermediate rotation member, and biasing the intermediate rotation member in the axial direction toward the input rotation member;
The clutch according to claim 1. The intermediate rotating member has a cam portion that generates axial thrust force by relative rotation with the input rotating member, and a disk-shaped flange portion formed on the outer peripheral side of the cam portion,
The housing has an annular recess that houses at least a portion of the flange portion;
The biasing member is accommodated in the annular recess of the housing.
The clutch according to claim 2. A driving source for generating a driving force for driving the front and rear wheels of the vehicle;
Driving force transmission that constantly transmits a driving force to a main driving wheel that is one of the front wheel and the rear wheel, and transmits the driving force to an auxiliary driving wheel that is the other of the front wheel and the rear wheel according to a vehicle running state. With the system,
The driving force transmission system is transmitted via the first differential gear device on the main driving wheel side, a propeller shaft, a first clutch that transmits driving force to the propeller shaft, and the propeller shaft. A second clutch for transmitting a driving force to the auxiliary drive wheel side; and a second differential gear device on the auxiliary drive wheel side;
The first clutch is a multi-plate clutch capable of adjusting a driving force transmitted to the propeller shaft,
The second clutch includes an input rotation member on the propeller shaft side, an output rotation member on the auxiliary drive wheel that can be relatively rotated coaxially with the input rotation member, the input rotation member, and the output rotation member. An intermediate rotating member interposed between the input rotating member and the output rotating member, and a torque that does not transmit torque from the output rotating member to the input rotating member.
The intermediate rotating member is limited to a predetermined range in relative rotation with the input rotating member, and moves in the axial direction by relative rotation with the input rotating member to make frictional contact with the output rotating member. In the propeller shaft and the first and second differential gear devices, the rotation member on the drive source side of the first clutch rotates faster than the rotation member on the propeller shaft side of the first clutch. Are connected by a gear mechanism in which the gear ratio is set,
The four-wheel drive vehicle according to claim 4. The second clutch is provided between the second differential gear device and a left rear wheel and a right rear wheel as the auxiliary driving wheels, respectively.
The four-wheel drive vehicle according to claim 4 or 5. The second clutch is provided between the propeller shaft and the second differential gear device.
The four-wheel drive vehicle according to claim 4 or 5.

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