JP6798234B2 - Differential - Google Patents

Description

The present invention relates to a differential device.

Conventionally, it is mounted on a four-wheel drive vehicle having a main drive wheel and an auxiliary drive wheel, and the drive force of the drive source is distributed to the left and right auxiliary drive wheels by allowing a differential, and the drive force to these auxiliary drive wheels is distributed. A differential device capable of blocking the transmission of the above is known (see, for example, Patent Document 1).

The differential device described in Patent Document 1 includes an outer case, an inner case arranged in the outer case, a differential mechanism housed in the inner case, and axially movable in the outer case. It includes a clutch member and an actuator that moves the clutch member in the axial direction. The actuator is located outside the outer case. The clutch member can be switched between a connected state in which the outer case and the inner case are connected so as not to rotate relative to each other and a non-connected state in which the inner case can rotate relative to the outer case by moving in the axial direction. In this connected state, the driving force input to the outer case is distributed from the differential mechanism to the left and right auxiliary drive wheels, and the vehicle is in a four-wheel drive state. Further, in the non-connected state, the transmission of the driving force to the auxiliary driving wheels is cut off, and the driving force is transmitted only to the main driving wheels, resulting in a two-wheel drive state.

Further, in the differential device described in Patent Document 1, a plurality of meshing teeth are formed on the facing surfaces of the outer case and the clutch member. Further, the clutch member and the inner case are connected to each other so that they can move relative to each other and cannot rotate relative to each other by meshing with each other a plurality of protrusions formed so as to project from their facing surfaces in the axial direction. Further, between the clutch member and the inner case, a shift spring made of a coil spring is arranged on the outside of the plurality of protrusions. This shift spring urges the clutch member in the meshing direction with the outer case. Then, when the actuator is not operating, the clutch member meshes with the outer case due to the urging force of the shift spring, and the driving force is transmitted from the outer case to the inner case via the clutch member. Further, the actuator presses the clutch member via the pressure plate by its operation, and disengages the clutch member from the outer case.

The differential device configured in this way does not need to operate the actuator when traveling in a four-wheel drive state, and even when traveling on a low μ road such as a snowy road for a long time, the heat generation and power consumption of the actuator are generated. It is possible to suppress consumption.

Japanese Unexamined Patent Publication No. 10-78110 (see paragraphs [0041] to [0066], FIGS. 1 to 3).

In the differential device described in Patent Document 1, since the shift spring is arranged in a slight gap between the plurality of protrusions of the inner case and the clutch member and the inner peripheral surface of the outer case, the shift spring having a large spring constant Is difficult to use. Therefore, the magnitude of the driving force transmitted from the outer case to the clutch member may be restricted. Further, if a large space for accommodating the shift spring is to be secured, the diameter of the outer case will be increased, and the size of the device will be increased and the weight will be increased.

Therefore, the present invention provides a differential device that does not need to operate the actuator when traveling in a four-wheel drive state and can sufficiently secure the pressing force of the urging member that urges the clutch member. The purpose is to provide.

For the purpose of solving the above problems, the present invention includes a differential mechanism that allows and distributes a driving force input to an input member to a pair of output members, and a differential case that accommodates the differential mechanism. , The clutch member housed in the differential case together with the differential mechanism, the relative rotation with the input member is restricted, and the clutch member is arranged so as to be relatively rotatable with respect to the differential case, and the clutch member is used as the rotation axis of the differential case. An urging member made of an elastic body that urges one side in the parallel axial direction, and an actuator that generates a pressing force that moves the clutch member to the other side in the axial direction against the urging force of the urging member. The differential case has a first meshing portion having a plurality of meshing teeth on one side wall of both side walls sandwiching the clutch member in the axial direction, and the clutch member is the one side wall thereof. thereby it has a second engaging portion having a plurality of meshing teeth on the end of the side engaging portion to be engaged with the engaged portion of the input member is formed so as to extend in the axial direction, and the input The urging member is movable relative to the member and the differential case in the axial direction, and the urging member is arranged in a state of being compressed in the axial direction between the other side wall of the both side walls and the clutch member. When the actuator does not generate the pressing force, the first meshing portion and the second meshing portion are meshed by the urging force of the urging member, and the differential case and the input member are engaged with each other via the clutch member. Provided is a differential device which is connected so as not to be able to rotate relative to each other and is disengaged between the first meshing portion and the second meshing portion by the pressing force generated by the operation of the actuator.

According to the differential device according to the present invention, it is not necessary to operate the actuator when traveling in the four-wheel drive state, and it is possible to secure the pressing force of the urging member that urges the clutch member.

It is sectional drawing which shows the structural example of the differential device which concerns on embodiment of this invention. It is an exploded perspective view of the differential device. It is a top view which looked at the 2nd case member of a differential device from the 1st case member side. It is a perspective view which shows the clutch member of a differential device, (a) is the perspective view seen from the 1st meshing part side, (b) is the perspective view seen from the leg part side. It is sectional drawing which shows the operation of the differential device by enlarging a part of the differential device, and shows the non-operating state of an actuator. It is sectional drawing which shows the operation of the differential device by enlarging a part of the differential device, and shows the operating state of an actuator. It is sectional drawing which shows the part of the differential device which concerns on one modification of this invention enlarged.

[Embodiment]
Embodiments of the present invention will be described with reference to FIGS. 1 to 6. It should be noted that the embodiments described below are shown as suitable specific examples for carrying out the present invention, and there are some parts that specifically exemplify various technically preferable technical matters. , The technical scope of the present invention is not limited to this specific aspect.

FIG. 1 is a cross-sectional view showing a configuration example of a differential device according to the first embodiment of the present invention. FIG. 2 is an exploded perspective view of the differential device. FIG. 3 is a plan view of the second case member of the differential device as viewed from the first case member side. FIG. 4 is a perspective view showing a clutch member of the differential device. FIG. 5 is a cross-sectional view showing the operation of the differential device by enlarging a part of the differential device, and shows a non-operating state of the actuator. FIG. 6 is a cross-sectional view showing the operation of the differential device by enlarging a part of the differential device, and shows the operating states of the actuators.

(Differential device configuration)
In the differential device 1 according to the present embodiment, the driving force of a driving source such as an engine is transmitted to a pair of left and right main driving wheels (for example, front wheels) at which the driving force of the driving source is always transmitted according to a traveling state. It is mounted on a four-wheel drive vehicle equipped with a pair of left and right auxiliary drive wheels (for example, rear wheels), and is used as a differential device that distributes driving force to the left and right wheels of the auxiliary drive wheels. Further, the differential device 1 can intermittently transmit the driving force to the auxiliary driving wheels. When the driving force is transmitted only to the main drive wheels, the vehicle is in a two-wheel drive state, and when the driving force is transmitted to the main drive wheels and the auxiliary drive wheels, the vehicle is in a four-wheel drive state. The differential device 1 distributes the input driving force to the left and right drive shafts on the auxiliary drive wheel side in the four-wheel drive state.

The differential device 1 includes a differential case 2 rotatably supported by a differential carrier 9 as a housing member fixed to a vehicle body via a pair of bearings 91 and 92, a differential mechanism 3 housed in the differential case 2, and a differential mechanism 3. A clutch mechanism 4 for intermittently transmitting a driving force between the differential case 2 and the differential mechanism 3 is provided. Lubricating oil (diff oil) that lubricates the differential mechanism 3 is introduced inside the diff case 2.

The differential case 2 is formed by connecting a first case member 21 and a second case member 22 that are parallel to each other in the rotation axis O direction. The first case member 21 is formed by forging, for example, and has a disk shape that covers the opening of the second case member 22. The flange portion 212 that is abutted with the flange portion 223 of the second case member 22 is integrally formed. Have. Further, the first case member 21 is formed with a shaft insertion hole 21a into which a drive shaft connected to one of the pair of side gears 32 so as not to rotate relative to the side gear 32 is inserted.

The second case member 22 has a bottomed cylindrical shape that accommodates the differential mechanism 3 and the clutch member 5, and the cylindrical cylindrical portion 221 and the end portion of the cylindrical portion 221 on the first case member 21 side are The side wall 222 extending inward from one end on the opposite side and the flange 223 protruding outward from the other end of the cylindrical portion 221 are integrally provided. In the differential case 2, the clutch member 5 is axially sandwiched between the side wall 222 of the second case member 22 as one side wall of both ends and the side wall 211 of the first case member 21 as the other side wall. To accommodate.

A plurality (four) through holes 222a are formed in the side wall 222 at intervals of about 90 degrees in the circumferential direction of the differential case 2. Further, a shaft insertion hole 222b is formed in the center of the side wall 222 into which a drive shaft connected to one of the side gears 32 of the pair of side gears 32 so as not to rotate relative to the side gear 32 is inserted. The plurality of through holes 222a and the shaft insertion hole 222b penetrate the side wall 222 in a direction parallel to the rotation axis O. Further, the differential case 2 has a first meshing portion 224 having a plurality of meshing teeth 220 on the inner surface of the side wall 222 (the surface facing the first case member 21). The plurality of meshing teeth 220 are provided at a part of the inner surface of the side wall 222 in the radial direction at equal intervals over the entire circumference. Further, the plurality of meshing teeth 220 of the first meshing portion 224 are side face splines formed radially on the surface of the side wall 222 of the second case member 22 facing the clutch member 5.

A driving force is input to the differential case 2 from a ring gear 23 (see FIG. 1) fixed to the flange portions 212 and 223 of the first and second case members 21 and 22. In the present embodiment, the plurality of bolt insertion holes 212a formed in the flange portion 212 of the first case member 21 and the plurality of bolt insertion holes 223a formed in the flange portion 223 of the second case member 22, respectively. The ring gear 23 is fixed so as to rotate integrally with the differential case 2 by the plurality of fastening bolts 24 inserted. In the fastening bolt 24, the head portion 241 abuts on the flange portion 212 of the first case member 21, and the shaft portion 242 on which the male screw is formed inserts the bolt insertion holes 212a and 223a into the screw hole 23a of the ring gear 23. It fits.

The first case member 21 and the second case member 22 are connected by a plurality of connecting bolts 25 (see FIG. 2). In the present embodiment, the first case member 21 and the second case member 22 are connected by four connecting bolts 25 before the ring gear 23 is fastened. In FIG. 2, three of these coupling bolts 25 are illustrated. The coupling bolt 25 is screwed into the screw hole 212b formed in the first case member 21 by inserting the bolt insertion hole 223b formed in the flange portion 223 of the second case member 22.

The differential mechanism 3 can distribute the driving force of the driving source input to the input member to the pair of output members while allowing differential. In the present embodiment, the differential mechanism 3 has a pair of pinion shafts 30, four pinion gears 31, and a pair of side gears 32 as rotating elements. The pair of pinion shafts 30 is an aspect of an input member, and the pair of side gears 32 is an aspect of a pair of output members. Of the four pinion gears 31, two pinion gears 31 are pivotally supported by one pinion shaft 30, and the other two pinion gears 31 are pivotally supported by the other pinion shaft 30. The pinion gear 31 and the side gear 32 are made of bevel gears, and the gear axes are orthogonal to each other and mesh with each other.

The left and right drive shafts are connected to the pair of side gears 32 so as not to rotate relative to each other. Ring plate-shaped washers 34 are arranged between the pair of side gears 32 and the first case member 21 and the second case member 22, respectively. Although a plurality of gear teeth are formed on the pinion gear 31 and the side gear 32, the illustration of these gear teeth is omitted in FIG.

Each pinion shaft 30 has a pair of engaged portions 301 that engage with the clutch member 5 of the clutch mechanism 4, which will be described later, a pair of pinion gear support portions 302 that are inserted into the pinion gear 31, and a pair of pinion gear support portions 302. It integrally has a connecting portion 303 to be connected, and is formed in a shaft shape as a whole. The pair of engaged portions 301 are provided at both ends of the pinion shaft 30, and the connecting portions 303 are provided at the central portion in the axial direction of the pinion shaft 30. The pair of pinion gear support portions 302 are provided between each of the pair of engaged portions 301 and the connecting portion 303, and pivotally support the pinion gear 31.

The pair of pinion shafts 30 are meshed with each other at the central portion in the axial direction thereof. Specifically, the connecting portion 303 of the other pinion shaft 30 is fitted into the recess 300 formed between the pair of pinion gear support portions 302 of the one pinion shaft 30, and the pair of pinion gears of the other pinion shaft 30. The connecting portion 303 of one pinion shaft 30 is fitted in the recess 300 formed between the supporting portions 302. The pair of pinion shafts 30 are orthogonal to each other when viewed along the rotation axis O of the differential case 2.

The clutch mechanism 4 serves as an urging member that urges the clutch member 5 and the clutch member 5 that can move in the central axis direction along the rotation axis O of the differential case 2 to one side in the axial direction parallel to the rotation axis O of the differential case 2. The wave washer 8 and the clutch member 5 are arranged between the clutch member 5 and the actuator 6 and the actuator 6 that generates a pressing force to push and move the clutch member 5 to the other side in the axial direction against the urging force of the wave washer 8. It is configured to have a clutch 7. The clutch member 5 is housed in the differential case 2 together with the differential mechanism 3, and is arranged between the differential mechanism 3 and the cylindrical portion 221 of the second case member 22. The actuator 6 is arranged outside the differential case 2, more specifically, outside the side wall 222 of the second case member 22. The transmission member 7 transmits the pressing force of the actuator 6 to the clutch member 5.

The clutch member 5 can move relative to the differential mechanism 3 in the direction of the central axis along the rotation axis O of the differential case 2, the relative rotation with the pinion shaft 30 is restricted, and the clutch member 5 rotates relative to the differential case 2. Arranged as possible.

The clutch member 5 is formed by forging a steel material, and has a cylindrical shape whose central axis coincides with the rotation axis O of the differential case 2, as shown in FIGS. 2 and 4. Specifically, the clutch member 5 has a plurality of cylindrical main body portions 52 and base end portions that are continuously formed on the main body portion 52 and extend axially toward the side wall 211 of the first case member 21. It has (4) legs 53 integrally. Further, the clutch member 5 has a plurality of meshing teeth 510 provided over the entire circumference on the end portion of the second case member 22 on the side wall 222 side, more specifically, on the axial end surface 52a of the main body portion 52. It has a second meshing portion 51 to have. Between each of the plurality of leg portions 53, an engaging portion 530 extending from the second meshing portion 51 side to the first case member 21 side and in which the pinion shaft 30 engages in the circumferential direction is provided. There is. Further, the plurality of meshing teeth 510 of the second meshing portion 51 are side face splines formed radially on the end surface 52a on the side wall 211 side of the first case member 21 in the main body portion 52 of the clutch member 5.

The second meshing portion 51 meshes with the first meshing portion 224 provided on the second case member 22 in the circumferential direction. The through hole 222a is formed so as to be located on the outer peripheral side of the first meshing portion 224. In the example shown in FIG. 3, the through hole 222a is formed so as to open to a part of the outer diameter side of the meshing tooth 220 in the radial direction of the second case member 22, but the clutch member 5 is the first. The entire meshing tooth 510 of the meshing portion 51 of 2 meshes with the meshing tooth 220 on the inner diameter side of the through hole 222a. However, a plurality of meshing teeth 220 may be formed only inside the through hole 222a.

The engaging portion 530 is formed as a groove that penetrates between the inner and outer peripheral surfaces of the clutch member 5 and extends in the central axis direction of the clutch member 5. Further, the leg portion 53 of the clutch member 5 has an annular receiving surface 53b that receives the urging force of the wave washer 8 as an urging member described later on the axial end surface of the tip portion 531 on the opposite side of the second meshing portion 51. have.

Engagement portions 301 provided at both ends of the pinion shaft 30 engage with the engagement portion 530. The clutch member 5 can move relative to the differential case 2 while maintaining an engaged state in which the engaged portion 301 of the pinion shaft 30 engages with the engaging portion 530 provided between the plurality of leg portions 53. Moreover, it cannot rotate relative to the pinion shaft 30 in the axial direction parallel to the rotation axis O of the differential case 2. The plurality of pinion gears 31 rotate (revolve) together with the clutch member 5 around the rotation axis O of the differential case 2.

A washer 33 is arranged between the back surface 31a of the plurality of pinion gears 31 and the inner peripheral surface 53a of the leg portion 53 of the clutch member 5. The washer 33 has a partially spherical inner surface 33a facing the back surface 31a of the pinion gear 31, and a flat outer surface 33b facing the inner peripheral surface 53a of the leg portion 53 of the clutch member 5. When the pinion gear 31 rotates (rotates) around the pinion shaft 30, the back surface 31a of the pinion gear 31 slides on the inner surface 33a of the washer 33. When the clutch member 5 moves in the central axis direction with respect to the pinion shaft 30, the inner peripheral surface 53a of the leg portion 53 of the clutch member 5 slides on the outer surface 33b of the washer 33.

The transmission member 7 has an annular portion 71 that abuts on the side wall 222 of the second case member 22, and a plurality of shaft portions 72 extending from the annular portion 71 in parallel with the rotation axis O of the differential case 2. ing. The plurality of shaft portions 72 are inserted into the through holes 222a and slide with the axial end surface 52a on the side of the main body portion 52 of the clutch member 5 where the second meshing portion 51 is provided. In the present embodiment, the transmission member 7 is provided with four shaft portions 72, and these shaft portions 72 are arranged evenly in the circumferential direction of the annular portion 71, in other words, at intervals of about 90 degrees. Further, the transmission member 7 is formed by pressing a steel plate, and the tip end portion of the shaft portion 72 (the end portion on the side opposite to the base end portion on the annular portion 71 side) is bent inward. Each of the shaft portions 72 of the transmission member 7 is inserted through a plurality of through holes 222a.

The actuator 6 includes an annular electromagnet 61 having a coil winding 611 and a mold resin portion 612 that molds the coil winding 611, and a yoke 62 that serves as a magnetic path for the magnetic flux of the electromagnet 61 generated by energizing the coil winding 611. The armcha 63 that slides into the mold resin portion 612 and is guided in the direction of the rotation axis O of the differential case 2 and presses the transmission member 7, and the yoke 62 moves in the axial direction with respect to the second case member 22 of the differential case 2. It has a regulating member 65 to regulate. The mold resin portion 612 has a rectangular cross section along the rotation axis O. The armature 63 moves the clutch member 5 in the direction in which the second meshing portion 51 meshes with the first meshing portion 224 of the differential case 2 by the magnetic force generated by energizing the coil winding 611. In the clutch member 5, the second meshing portion 51 is meshed with the first meshing portion 224 by the pressing force of the actuator 6 transmitted via the transmission member 7.

Excitation current is supplied to the coil winding 611 from the control device (not shown) via the electric wire (not shown) led out from the boss portion 612c provided in the mold resin portion 612. The actuator 6 operates by supplying an exciting current to the coil winding 611. Since the actuator 6 is arranged outside the differential case 2, it is easy to supply a current to the coil winding 611.

The yoke 62 is made of a soft magnetic metal such as low carbon steel, and as shown in FIGS. 5 and 6, the yoke 62 has a cylindrical portion 621 that covers the inner peripheral surface 612b of the mold resin portion 612 from the inside and a cylindrical portion 621 in the axial direction. It integrally has a flange portion 622 that projects outward from one end portion and covers the axial end surface 612c of the mold resin portion 612. The inner diameter of the cylindrical portion 621 is formed to be slightly larger than the outer diameter of the differential case 2 of the portion of the cylindrical portion 621 facing the inner peripheral surface 621a.

A stopper ring 64 is fixed to the end of the cylindrical portion 621 of the yoke 62 opposite to the flange portion 622. The stopper ring 64 is made of a non-magnetic metal such as austenitic stainless steel, and has an annular portion 641 connected to the yoke 62, a pair of protrusions 642 protruding axially from the annular portion 641 at two locations in the circumferential direction, and protrusions. It integrally has a folded-back portion 643 that is folded back at an acute angle from the tip portion of the portion 642. In the stopper ring 64, a pair of protrusions 642 are locked to the recess 90 of the differential carrier 9 to prevent rotation.

The annular portion 641 is axially opposed to the axial end surface 612d of the mold resin portion 612 (the end surface opposite to the axial end surface 612c facing the flange portion 622 of the yoke 62). The annular portion 641 has an engaging protrusion 641a protruding in the radial direction at the end on the inner diameter side thereof, and the engaging protrusion 641a engages with an engaging recess 642a formed in the cylindrical portion 621 of the yoke 62. It fits. In the stopper ring 64, the engaging protrusion 641a engages with the engaging recess 642a to prevent the yoke 62 from rotating with respect to the differential carrier 9.

The armature 63 is made of a soft magnetic metal such as low carbon steel, and has an annular outer ring portion 631 arranged on the outer periphery of the electromagnet 61, a side plate portion 632 that faces the electromagnet 61 in the axial direction, and a shaft of the outer ring portion 631. It integrally has a flange portion 633 formed so as to project outward from the end portion on the differential case 2 side in the direction. The outer ring portion 631 has a cylindrical shape that covers the electromagnet 61 from the outer peripheral side. The side plate portion 632 projects inward from one end of the outer ring portion 631 in the axial direction and faces the regulation member 65 in the axial direction. The flange portion 633 comes into contact with the annular portion 71 of the transmission member 7.

In the armature 63, the inner peripheral surface 631a of the outer ring portion 631 is in contact with the outer peripheral surface 612a of the mold resin portion 612 and is supported by the electromagnet 61. When the armature 63 moves in the axial direction, the inner peripheral surface 631a of the outer ring portion 631 slides on the outer peripheral surface 612a of the mold resin portion 612.

As shown in FIG. 2, an engaging hole 632a that engages with the protrusion 642 of the stopper ring 64, an insertion hole 632b through which the boss portion 612c of the electromagnet 61 is inserted, and lubricating oil flow through the side plate portion 632 of the armature 63. A plurality of oil holes 632c (9 in the example shown in FIG. 2) are formed. Further, the surface 71a of the annular portion 71 of the transmission member 7 opposite to the differential case 2 is in contact with the surface 633a of the flange portion 633 on the differential case 2 side. The armature 63 is prevented from coming off from the stopper ring 64 by the folded-back portion 643 of the stopper ring 64, and the protrusion 642 is engaged with the engagement hole 632a to prevent the armature 63 from rotating with respect to the differential carrier 9. The protrusion 642 of the stopper ring 64 is locked to the differential carrier 9 through the engaging hole 632a.

The regulating member 65 is an annular member made of a soft magnetic metal such as low carbon steel, and is arranged between the stopper ring 64 and the annular portion 632 of the armature 63. Further, the end portion of the regulating member 65 on the inner diameter side is fixed to the end portion of the cylindrical portion 621 of the yoke 62 by welding, for example, and restricts the axial movement of the stopper ring 64 with respect to the cylindrical portion 621 of the yoke 62. There is.

A wave washer 8 as an annular urging member made of an elastic body is arranged between the tip portion 531 of the plurality of leg portions 53 and the side wall 211 of the first case member 21. The wave washer 8 is fitted onto the annular protrusion 213 provided at the end of the first case member 21 on the second case member 22 side, and is in contact with the receiving surface 53b at the tip of the leg portion 53 of the clutch member 5. There is. The wave washer 8 is arranged between the side wall 211 of the first case member 21 and the clutch member 5 in a state of being compressed in the axial direction. The clutch member 5 is urged on the side wall 222 side of the second case member 22 by the urging force (restoring force) of the wave washer 8.

In the present embodiment, the urging member is a wave washer 8, but the urging member is not limited to this, and the urging member may be formed by a coil spring or rubber. Further, in the present embodiment, the wave washer 8 is an annular shape arranged between the differential mechanism 3 and the first case member 21, but the present invention is not limited to this, and the receiving surface of the leg portion 53 of the clutch member 5 is not limited to this. The urging members may be arranged at a plurality of locations facing the 53b.

(Operation of differential device)
In the differential device 1, the second meshing portion 51 and the first meshing portion 224 mesh with each other in the circumferential direction due to the operation and non-operation of the actuator 6, and the clutch member 5 and the differential case 2 are connected so as not to rotate relative to each other. The engaged state is switched between the non-connected state in which the clutch member 5 and the differential case 2 can rotate relative to each other.

When the exciting current is not supplied to the coil winding 611 of the electromagnet 61, that is, when the actuator 6 is not operating without generating a pressing force, the clutch member 5 is moved by the urging force of the wave washer 8 to the second case member 22. The second meshing portion 51 and the first meshing portion 224 are urged toward the side wall 222 side to mesh with each other, and the differential case 2 and the clutch member 5 are connected so as not to rotate relative to each other. As a result, the differential case 2 and the pinion shaft 30 are connected so as not to rotate relative to each other. In other words, the differential case 2 and the pinion shaft 30 are connected via the clutch member 5 so as not to rotate relative to each other. Further, in the armature 63, when the electromagnet 61 is not energized, the plate portion 632 comes into contact with the folded portion 643 of the stopper ring 64 by the urging force of the wave washer 8 transmitted via the clutch member 5 and the transmission member 7. Returned to position.

When the actuator 6 is inactive, the second meshing portion 51 and the first meshing portion 224 mesh with each other, and the driving force input from the ring gear 23 to the first case member 21 of the differential case 2 is the clutch member 5. It is transmitted to the drive shaft via the pair of pinion shafts 30 of the differential mechanism 3, the four pinion gears 31, and the pair of side gears 32, and the vehicle is in a four-wheel drive state.

When an exciting current is supplied to the coil winding 611 of the electromagnet 61, the side plate portion 632 of the armature 63 moves to the flange portion 622 side (see FIG. 5) of the yoke 62 by the magnetic force of the electromagnet 61. As a result, the transmission member 7 presses the clutch member 5 toward the first case member 21, and the engagement between the second meshing portion 51 and the first meshing portion 224 is released. Specifically, the transmission member 7 receives the pressing force of the actuator 6 from the surface 71a of the annular portion 71 opposite to the differential case 2 via the flange portion 633 of the armature 63, and the pressing force causes the clutch member 5 to move. Press against the case member 21 side of 1. In other words, the pressing force generated by the operation of the actuator 6 releases the meshing between the first meshing portion 224 and the second meshing portion 51.

When the meshing between the second meshing portion 51 and the first meshing portion 224 is released, the differential case 2 and the clutch member 5 can rotate relative to each other, so that the driving force can be transmitted from the differential case 2 to the differential mechanism 3. It is cut off. As a result, the driving force input from the ring gear 23 to the differential case 2 is not transmitted to the drive shaft, and the vehicle is in a two-wheel drive state.

The axial position of the armature 63 is detected by the position sensor 93 fixed to the differential carrier 9, and the detection signal is transmitted to the control device. The position sensor 93 has a rod 931 that abuts on the side plate portion 632 of the armature 63. The control device can recognize the position of the armature 63 by the detection signal of the position sensor 93, and can determine whether or not the second meshing portion 51 and the first meshing portion 224 are meshed with each other.

When the actuator 6 is moved from the non-operating state to the operating state, the control device supplies an exciting current having a large current value capable of rapidly moving the clutch member 5 to the electromagnet 61, and then supplies a second meshing portion 51. When it is determined that the meshing with the first meshing portion 224 is disengaged, the current value of the exciting current is changed to the state in which the meshing between the second meshing portion 51 and the first meshing portion 224 is disengaged. The current value is reduced to a relatively small value that can be maintained. As a result, power consumption can be reduced.

(Modification example)
FIG. 7 is an enlarged cross-sectional view showing a part of the differential device according to the modified example. In the above-described embodiment, the through hole 222a is formed on the outer peripheral side of the first meshing portion 224, the tip portion of the shaft portion 72 of the transmission member 7 is bent inward, and the ring portion 71 is the armature 63. It is configured to abut with the flange portion 633 formed so as to project outward from the outer ring portion 631, but as shown in FIG. 7, the through hole 222a of the first meshing portion 224 having a plurality of meshing teeth 220. It can also be configured so that it is formed on the inner peripheral side, the tip end portion of the shaft portion 72 is bent inward, and the annular portion 71 abuts on the inner peripheral side of the side plate portion 632 of the armature 63. In this case, the armature 63 does not have to be provided with the flange portion 633.

(Actions and effects of embodiments)
According to the first embodiment and its modification described above, the first meshing portion 51 of the clutch member 5 and the second meshing portion 224 of the differential case 2 are meshed by the urging force of the wave washer 8 to form a vehicle. It becomes a four-wheel drive state. Therefore, it is not necessary to energize the electromagnet 61 when traveling in the four-wheel drive state. Further, by arranging the wave washer 8 between the side wall 211 of the first case member 21 and the clutch member 5, it is possible to sufficiently secure a storage space for the wave washer 8. Therefore, as the urging member, even when the drive source generates the maximum output, the meshing state of the first meshing portion 51 of the clutch member 5 and the second meshing portion 224 of the differential case 2 is sufficiently maintained. It is possible to use a clutch having a large spring constant.

(Additional note)
Although the present invention has been described above based on the first embodiment and its modifications, the present invention is not limited to these embodiments and is appropriately modified without departing from the spirit of the present invention. It is possible to carry out.

1 ... Differential device 2 ... Diff case 211,222 ... Side wall 220 ... Meshing teeth 224 ... First meshing portion 3 ... Differential mechanism 5 ... Clutch member 51 ... Second meshing portion 510 ... Meshing teeth 52 ... Main body portion 52a ... End face 53 ... Leg 531 ... Tip 6 ... Actuator 8 ... Wave washer (biasing member)

Claims (4)

A differential mechanism that allows and distributes the driving force input to the input members to a pair of output members,
A differential case that houses the differential mechanism and
A clutch member housed in the differential case together with the differential mechanism, the relative rotation with the input member is restricted, and the clutch member is arranged so as to be relatively rotatable with respect to the differential case.
An urging member made of an elastic body that urges the clutch member on one side in the axial direction parallel to the rotation axis of the differential case.
The clutch member is provided with an actuator that generates a pressing force that moves the clutch member to the other side in the axial direction against the urging force of the urging member.
The differential case has a first meshing portion having a plurality of meshing teeth on one side wall of both side walls that sandwich the clutch member in the axial direction.
The clutch member includes a second engagement portion as well as have the engaging portion to be engaged with the engaged portion of the input member is the axial direction having a plurality of meshing teeth on the end of the said one side wall It is formed so as to extend in the axial direction, and can move relative to the input member and the differential case.
The urging member is arranged in an axially compressed state between the other side wall of the both side walls and the clutch member.
When the actuator does not generate the pressing force, the first meshing portion and the second meshing portion are meshed by the urging force of the urging member, and the differential case and the input member communicate with each other via the clutch member. Connected so that they cannot rotate relative to each other
The pressing force generated by the operation of the actuator releases the meshing between the first meshing portion and the second meshing portion.
Differential device. The clutch member has a plurality of legs extending in the axial direction toward the other side wall, and a groove extending axially between the plurality of legs is formed as the engaging portion. ,
The clutch member can move in the axial direction with respect to the differential case while maintaining an engaged state in which the input member engages between the plurality of legs.
The differential device according to claim 1. In the clutch member, the base end portions of the plurality of legs are continuously and integrally formed on a cylindrical main body portion in which the second meshing portion is provided over the entire circumference.
The urging member is arranged between the tip portions of the plurality of legs and the other side wall.
The differential device according to claim 2. The plurality of meshing teeth of the first meshing portion are side face splines formed radially on the surface of one side wall facing the clutch member.
The plurality of meshing teeth of the second meshing portion are side face splines formed radially on the end surface on the one side wall side of the main body portion of the clutch member.
The differential device according to claim 3.

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