JPH0651595U - Differential device - Google Patents

Abstract

(57) [Summary] [Purpose] The response is good and the running stability can be improved. A differential case 21 that receives a rotation input, and a differential mechanism that is provided in the differential case 21 and that transmits the rotation input of the differential case 21 to a pair of output rotary members and that allows a differential rotation between the output rotary members. 42, a pilot clutch 57 that exerts a limiting force on the differential rotation by engaging the engaging means, and the pilot clutch 57.
Cam 6 that generates an engaging force according to the differential rotation, a main clutch 43 that is engaged by the engaging force of the cam 65 to limit the differential rotation, and the cam 6
The elastic member 81 for absorbing the gap 5 is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a differential device used for a power system of a vehicle.

[0002]

[Prior art]

 Japanese Utility Model Laid-Open No. 4-63855 discloses a differential device having a differential limiting mechanism.

As shown in FIG. 6, this differential limiting mechanism limits the differential rotation of the differential mechanism 107 by engaging the main clutch 105 with the thrust force of the cam 103 that receives the differential torque via the pilot clutch 101. Is configured to. The differential mechanism 107 is a planetary gear type arranged in the differential case 109, and its pinion carrier 111 serves as a pressing member of the main clutch 105 by the cam thrust force.

The pilot clutch 101 is engaged when the armature 115 is attracted by the electromagnet 113, and when the engaging force (slip) of the pilot clutch 101 is adjusted by the electromagnet 113, the engaging force of the main clutch 105 changes and the differential mechanism 107. The differential limiting force of can be controlled.

[0005]

[Problems to be solved by the device]

 However, in the conventional differential device as described above, since the cam 103 has a play corresponding to the assembling clearance, in the low current region or the region where the differential rotation is small, as shown in FIG. For example, in the case of a left turn, the inertial force F of the armature 115 may act in a direction that causes the rattling S of the cam 103, which may or may not generate a differential torque, resulting in unstable characteristics. On the other hand, in the case of a right turn, the inertial force F of the armature 115 acts on the cam 103 in a direction to suppress the play of the assembling clearance, and a stable differential limiting characteristic is obtained.

Therefore, in slalom traveling, since the steering angle is extremely small, the turning force in the opposite direction is entered before the thrust force of the cam 103 is applied, that is, before the torque is generated, and there is a limit to improvement of traveling stability. was there.

Therefore, the present invention aims to provide a differential device capable of further improving running stability.

[0008]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention provides a differential case that receives a rotation input, and a differential case that is provided in the differential case and that transmits the rotation input of the differential case to a pair of output rotary members and that performs differential rotation between the output rotary members. A differential mechanism that allows, a pilot clutch that exerts a limiting force on the differential rotation by engaging the engaging means, and a cam that produces an engaging force according to the differential rotation by the limiting force of the pilot clutch, A main clutch that is fastened by the fastening force of the cam to limit the differential rotation, and an elastic member that absorbs a gap between the cams are provided.

[0009]

[Action]

 The engagement force of the main clutch changes according to the engagement force (slip) of the pilot clutch, limiting the differential of the differential mechanism. If the engaging force of each clutch is large enough, the differential is locked, and if the engaging force is moderately loosened, the differential is allowed.

In the differential limiting control performed in this manner, the initial torque is applied to the main clutch by the spring force of the elastic member, and the rattling of the cam is eliminated, so that even when the engaging force of the pilot clutch is small. The cam works quickly, the response is improved, and the running stability is improved during slalom running with a small steering angle.

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a differential device according to an embodiment of the present invention, and FIG. 2 shows a power system of a vehicle using this device. Hereinafter, the left-right direction of FIG. 1 is the left-right direction of this vehicle, and the front of this vehicle corresponds to the upper side of FIG.

As shown in FIG. 2, this vehicle has an engine 1, a transmission 3, left and right front wheels 5, 7, a propeller shaft 9, a rear differential 11 (a differential device in FIG. 1), rear axles 13, 15, and left and right rear wheels. It is composed of wheels 17 and 19.

The differential case 21 of the rear differential 11 is rotatably arranged in the differential carrier 23. A ring gear 25 is fixed to the differential case 21, and the ring gear 25 meshes with a drive pinion gear 29 that is integral with a drive pinion shaft 27 connected to the propeller shaft 9. Thus, the differential case 21 is rotationally driven by the driving force from the engine 1.

As shown in FIG. 1, a left boss 31 and a right boss 33 are coaxially and relatively rotatably arranged inside the differential case 21, and the left and right bosses 31 and 33 have a pair of left and right side gears. 35 and 37 are incorporated.

The left boss 31 is spline-connected to the left rear axle 13, and the right boss 33 is spline-connected to the right rear axle 15.

Inside the differential case 21, a pinion gear 39 which is constantly meshed with the both side gears 35 and 37 is arranged, and the pinion gear 39 is rotatably supported by a pinion shaft 41. The end of the pinion shaft 41 is fixed to the differential case 21.

Therefore, when the differential case 21 is rotationally driven, the rotation of the differential case 21 is transmitted to the left and right side gears 35 and 37 via the pinion shaft 41 and the pinion gear 39, and the bosses 31 and 33 and the rear axles 13 and 15 are transmitted. Are transmitted to the left and right rear wheels 17 and 19 respectively.

The differential case 21, the side gears 35, 37, and the pinion gear 39 constitute a differential mechanism 42 as a whole.

A main clutch (friction clutch) 43 is arranged between the differential case 21 and the right side gear 37 as a differential limiting means for limiting the differential between the two. A shim 45 for adjusting the thickness is arranged between the differential case 21 and the main clutch 43. The main clutch 43 comprises a plurality of outer and inner friction plates 43a and 43b arranged alternately. The outer friction plate 43a is spline-coupled to the inner peripheral surface of the differential case 21 in the axial movement direction, and the inner friction plate 43a. 43b is splined to the outer peripheral surface of the boss portion of the side gear 37 so as to be movable in the axial direction.

A pressure ring (pressing member) 47 is arranged on the right side of the main clutch 43. The pressure ring 47 is spline-coupled to the outer peripheral surface of the right boss 33 so as to be movable in the axial direction, presses the friction plates 43a and 43b to bring them into contact with each other, and fastens the main clutch 43.

A cam ring 55 is arranged on the right side of the pressure ring 47, and a cam 65 is formed between the cam ring 55 and the pressure ring 47 via a ball 63. A needle bearing 67 and a washer 69 are arranged between the cam ring 55 and the differential case 21.

A preload plate 49 having a shape as shown in FIGS. 3 and 4 is arranged between the main clutch 43 and the pressure ring 47. As shown in FIGS. 3 and 4, the preload plate 49 has a plurality of (four in the figure) pressing plate portions 49b for pressing the friction plates of the main clutch 43 on the outer periphery of the annular plate body 49a. It is mounted in a concave portion 51 formed in the side gear 37 so as to be movable in the axial direction through a connecting portion 49c between the pressure plate portion 49b and the pressing plate portion 49b.

The preload plate 49 constantly presses the main clutch 43 by a spring 53, which is an elastic member provided between the preload plate 49 and the pressure ring 47, to give an appropriate initial torque. It is input to the differential case 21 via the ball cam 65, the cam ring 55, the needle bearing 67 and the washer 69. As a result, the backlash of the cam 65 is absorbed. The preload plate 49 and the spring 53 constitute a preload member.

A pilot clutch (friction clutch) 57 that connects the cam ring 55 and the differential case 21 is arranged between the cam ring 55 and the differential case 21.

The pilot clutch 57 includes a plurality of outer and inner friction plates 57 a and 57 b arranged alternately. The outer friction plate 57 a is spline-coupled to the inner peripheral surface of the differential case 21 so as to be movable in the axial direction, and the inner friction plate 57 a. The friction plate 57b is spline-coupled to the outer peripheral surface of the cam ring 55 so as to be axially movable. An armature 59 is arranged on the left side of the pilot clutch 57 and is positioned by a retaining ring 61 provided on the differential case 21.

A ring-shaped electromagnet 73 is arranged on the right side of the right side wall 71 of the differential case 21. The electromagnet 73 is rotatably supported by the boss 76 of the differential case 21 via a bearing 75, and is fixed to the differential carrier 23 by a support member (not shown). The electromagnet 73 constitutes a fastening means for the pilot clutch 57.

A non-magnetic ring 77 is embedded in the right side wall 71 of the differential case 21 to prevent the magnetic lines of force of the electromagnet 73 from being short-circuited and lead to the armature 59. When the exciting current is supplied to the electromagnet 73 and the armature 59 is attracted, the pilot clutch 57 is engaged and the cam ring 55 is connected to the differential case 21 via the pilot clutch 57.

When the cam ring 55 is connected to the differential case 21 by the pilot clutch 57, the differential limiting of the differential mechanism 42 is performed according to the fastening force (slip) of the pilot clutch 57.

Further, when the pilot clutch 57 is engaged, the differential torque of the differential mechanism 42 acts on the cam 65, and left and right thrust forces are generated. The main clutch 43 is pressed and engaged with the differential case 21 via the pressure ring 47 and the preload plate 49 by the thrust force in the left direction. In this way, the engagement force of the main clutch 43 is added to the engagement force of the pilot clutch 57, and the differential limiting force of the differential mechanism 42 is strengthened. The left and right thrust forces are input to the differential case 21 and are offset by each other.

When the slip of the pilot clutch 57 is adjusted by the electromagnet 73, the fastening force of the main clutch 43 changes, and the differential limiting force of the differential mechanism 42 can be controlled. If the fastening force of each clutch 57, 43 is sufficiently large, the differential is locked, and if the fastening force is loosened appropriately, the differential is allowed. When the pilot clutch 57 is released, the main clutch 43 is also released and the differential becomes free.

The operation of the pilot clutch 57 by the electromagnet 73 can be manually operated from the driver's seat, or can be automatically operated according to the road surface condition, the steering condition of the vehicle, and the like.

Thus, the rear differential 11 is constructed.

Next, the function of the rear differential 11 will be described according to the performance of the vehicle shown in FIG.

When the pilot clutch 57 is opened, the rear differential 11 freely allows the differential between the left and right rear wheels. This allows the vehicle to make smooth turns and prevent the tight corner braking phenomenon. When the pilot clutch 57 is engaged, the rear differential 11 limits the differential between the left and right rear wheels according to the engagement force.

Therefore, even if one of the rear wheels 17, 19 slips on a bad road or the like, the driving force is transmitted to the other rear wheel by the torque transmission due to the differential limitation, so that the vehicle does not fall into the stuck state. You can escape from the rough road.

In the differential limiting control performed as described above, according to this embodiment, the initial force is applied to the main clutch by the spring force of the spring 53, and the inertia force of the armature 59 causes the cam 65 to rattle. Even if the cam 65 is moved in the direction of expanding, the backlash is not formed on the cam 65, and the cam 65 can immediately act. Therefore, the response is improved even when the engagement force of the pilot clutch is small, and the traveling stability can be improved during slalom traveling with a small steering angle.

Since the preload plate 49 and the spring 53 are arranged in the space on the inner peripheral side of the main clutch 43 arranged on the outer peripheral side in the differential case 21 in order to obtain a large differential limiting force, the rotary shaft of the differential case 21 is arranged. It is not necessary to lengthen it in the direction, and the initial torque is applied by the spring force to eliminate the backlash of the cam 65 at the same time and in series.

FIG. 5 shows another embodiment of the present invention. This embodiment is a modification of the above embodiment, and is arranged as a rear differential 79 in the vehicle shown in FIG. 5, the same components as those in FIG. 1 are designated by the same reference numerals, and the differences will be described below.

A disc spring 81 is arranged as an elastic member between the shim 45 on the left side of the main clutch 43 and the differential case 21, and the pressure ring (pressing member) 47 on the right side of the main clutch 43 is a friction plate. Is engaged with.

The disc spring 81 constantly presses the main clutch 43 to give an appropriate initial torque, and the pressing force is applied to the differential case 21 via the pressure ring 47, the ball cam 65, the cam ring 55, the needle bearing 67 and the washer 69. Is entered. As a result, the backlash of the cam 65 is absorbed.

This embodiment also has the same functions and effects as the differential device of the embodiment of FIG. 1, and the function of the rear differential 79 in the vehicle is also the same as that of the rear differential 11 shown in FIG.

[0043]

[Effect of device]

 As is clear from the above description, according to the configuration of the present invention, the spring force of the elastic member applies the initial torque to the main clutch, and the backlash of the cam is eliminated, so that the cam can always be quickly operated. Response is improved and running stability can be improved.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a differential device according to an embodiment of the present invention.

FIG. 2 is a skeleton mechanism diagram showing a power system of a vehicle using the device of each embodiment.

3 is a plan view showing the preload member of FIG. 1. FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a schematic cross-sectional view showing a differential device according to another embodiment of the present invention.

FIG. 6 is a schematic transverse sectional view of a differential device according to a conventional example.

FIG. 7 is an operation explanatory view.

[Explanation of symbols]

 21 differential case 35, 37 side gear 39 pinion gear 42 differential mechanism 43 main clutch 57 pilot clutch 65 cam 73 electromagnet (fastening means) 81 disc spring (elastic member)

Claims (1)

[Scope of utility model registration request] 1. A differential case that receives a rotational input, and a differential mechanism that is provided in the differential case and that transmits the rotational input of the differential case to a pair of output rotary members and that allows differential rotation between the output rotary members. , A pilot clutch that exerts a limiting force on the differential rotation by engaging the engaging means, a cam that produces an engaging force according to the differential rotation by the limiting force of the pilot clutch, and an engagement force by the cam. A differential device, comprising: a main clutch that limits the differential rotation; and an elastic member that absorbs a gap between the cams.