JPH0648199A - Differential gear - Google Patents

Abstract

PURPOSE:To obtain substantially sufficient differential limiting force even with the malfunction of a pressing means for a differential limiting friction clutch. CONSTITUTION:A differential gear 7 is provided with differential gear mechanism 33 for generating thrust by the mesh of differential gears 37, 41, a differential limiting friction clutch 69, and pressing means 87 for pressing the friction clutch 69 so as to adjust differential limiting force. The differential gear 7 is also formed in such a way that the friction clutch 69 is locked by receiving thrust.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle differential device.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 63-195449 discloses a differential device 201 as shown in FIG.
This is a differential device arranged on the axle, and is configured to engage the multi-plate clutch 203 with the electromagnet 205 to limit the differential of the differential mechanism 207. When the multi-plate clutch 203 is engaged. A cam 209 that receives the differential torque of the differential mechanism 207 and presses the multi-plate clutch 203.
Is equipped with.

[0003]

FIG. 6 is a torque distribution characteristic diagram of the differential device 201.
Reference numerals 1 and 213 are shaft torques respectively sent to the left wheel and the right wheel when the right wheel and the left wheel idle. The 45 ° graph 215 is a theoretical characteristic when the multi-plate clutch 203 is released. According to this characteristic, when one wheel idles, the wheel torque of the other wheel also becomes zero, but in reality the difference is Due to the friction of the moving mechanism 207, the characteristics shown in the graphs 217 and 219 are obtained. Thus, the differential device 201
Then, for example, when the electromagnet 205 is out of order, the multi-plate clutch 2
03 does not operate and the multi-plate clutch 203 is not engaged, the cam 209 does not operate either, so that a differential limiting force is hardly obtained as shown in graphs 217 and 219.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a differential device capable of obtaining a substantially sufficient differential limiting force even if the pressing means of the differential limiting friction clutch should malfunction.

[0005]

A differential gear mechanism that produces a thrust force by meshing of differential gears, a friction clutch for limiting a differential, and a pressing unit that presses the friction clutch to adjust the differential limiting force. And the friction clutch is configured to be fastened by receiving the thrust force.

[0006]

The friction clutch is strongly engaged by the thrust force generated by the meshing of the differential gear in addition to the pressure by the pressing means, and a large differential limiting force is obtained. Further, even if the pressing means fails, a sufficient differential limiting force is always obtained by the meshing thrust force, and the maneuverability is maintained. Further, both torque-sensitive type differential limiting characteristics due to the mesh thrust force and arbitrary differential limiting characteristics due to the pressing means can be obtained, and it is possible to cope with a wide range of changes in running conditions.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described with reference to FIGS. 1, 2 and 4. FIG. 1 shows this embodiment, and FIG. 4 shows a power system of a vehicle using this embodiment. Left and right direction is this vehicle and Fig. 1
The left and right directions.

As shown in FIG. 4, this power system includes an engine 1, a transmission 3, a propeller shaft 5, a rear differential 7 (a differential device of the embodiment arranged on the rear wheel side), rear axles 9, 11 and left and right rear. It is composed of wheels 13, 15 and left and right front wheels 17, 19. The differential case 21 of the rear differential 7 is rotatably arranged in the differential carrier 23, and a ring gear 27 fixed to the differential case 21 with a bolt 25 meshes with a drive pinion gear 31 integral with the drive pinion shaft 29, and the drive pinion shaft 29. Is connected to the propeller shaft 5 side. Thus, the differential case 21 is rotationally driven by the driving force from the engine 1.

As shown in FIG. 1, a bevel gear type differential mechanism 33 is arranged inside the differential case 21. This differential mechanism 33 includes a pinion gear 37 (differential gear) rotatably supported on a pinion shaft 35, and a pinion gear 3
7, and left and right side gears 39 and 41 meshing with 7. The left side gear 39 is spline-connected to the left rear axle 9, and the right side gear 41 (differential gear) is spline-connected to the right rear axle 11. Both ends of the pinion shaft 35 are supported by the spherical washer 43, and the spherical washer 43 is spline-connected to the inner circumference of the differential case 21. A washer 48 is arranged between the side gear 39 and the differential case 21.

The driving force of the engine 1 input to the differential case 21 is distributed from the spherical washer 43, the pinion shaft 35, and the pinion gear 37 to the left and right rear wheels 13 and 15 via the site gears 39 and 41. When a difference in driving resistance occurs between the rear wheels, the driving force of the engine 1 is differentially distributed to the left and right sides due to the rotation and revolution of the pinion gear 37.

Between the side gears 39, 41 and the differential case 21, multi-plate type main clutches 51, 53 are arranged, respectively. A pressing member 52 is arranged on the left side of the right main clutch 53. The pressing member 52 has a leg portion between the spherical washers 43 and can press the left main clutch. Further, a ball cam 55 is arranged on the right side of the right main clutch 53. The ball cam 55 includes the left and right cam rings 57 and 59 and the ball 6.
1, the left cam ring 57 is splined to the differential case 21 so as to be movable in the axial direction, and the ball cam 55 is provided between the right cam ring 59 and the differential case 21.
A bearing 63 for receiving the thrust reaction force of is arranged. An outer friction plate 65 engages with the cam ring 59, and an inner friction plate 67 engages with the right side gear 41 to form a multi-plate pilot clutch 69.

Pilot clutch 69 and differential case 21
A pressure receiving ring 71 is disposed between and.

A ring-shaped pressing member 73 is arranged between the right side gear 41 and the pilot clutch 69. A plurality of legs 75 are formed on the pressing member 73,
These legs 75 penetrate one of the left inner friction plates 67 and can press the other right friction plates 65, 67. The left side portion corresponding to the friction plate through which the leg 75 penetrates is the first group 77 of the pilot clutch 69, and the other right side portion is the second group 79. The right side gear 41 is meshed with the pinion gear 37 to generate a thrust force in the right direction, and this thrust force presses and fastens the second group 79 of the pilot clutch 69 via the pressing member 73.
When the pilot clutch 69 of the second group 79 is engaged, the differential torque between the differential case 21 and the side gear 41 is applied to the ball cam 55, the cam thrust force engages the right main clutch 53, and the left side via the pressing member 52. The main clutch 51 of is engaged. Each clutch 79,
The differential force of the differential mechanism 33 is limited by the connecting force of 51 and 53.

FIG. 2 is a torque distribution characteristic diagram showing the axial torque sent to the other wheel when one of the rear wheels 13, 15 idles. Graph 81 shows the torque distribution characteristic when there is no differential limiting function. is there. The meshing thrust force of the side gear 41 becomes stronger as the transmission torque increases, so that the graphs 83, 8
Within the range of 5, torque distribution characteristics sensitive to the transmission torque can be obtained.

On the right side of the differential case 21, a ring-shaped electromagnet 87 (pressing means) is arranged. The electromagnet 87 is mounted on the right boss portion 9 of the differential case 21 by the bearings 89, 89.
It is supported by No. 1 and is prevented from rotating on the side of the differential carrier 23. Also, the electromagnet 87 and the right side wall 9 of the differential case 21
A ring-shaped armature 95 is arranged between the armatures 3 and 3. The plurality of legs 97 provided on the armature 95 are provided with openings 99, 1 provided on the right side wall 93 and the outer friction plate 65.
01, and its tip is bent radially inward to form a pressing portion 103 of the pilot clutch 69. The electromagnet 87 attracts the armature 95 and presses the pilot clutch 69 (the first group 77 and the second group 79) with the pressing portion 103 to engage them to adjust the engagement force.

A pilot clutch 69 is provided by an electromagnet 87.
When is fastened, the main clutches 51 and 53 are fastened by the cam thrust force of the ball cam 55 as described above,
The differential of the differential mechanism 33 is limited. The differential limiting force by the electromagnet 87 is added to the graphs 83 and 85 to become a large differential limiting force, and torque distribution characteristics as shown in the graphs 105 and 107 are obtained. Graph 8 by adjusting the magnetic force of the electromagnet 87
The torque distribution characteristic can be arbitrarily controlled between the graph 3 and the graph 105 and between the graph 85 and the graph 107.

The rear differential 7 is thus constructed.

When traveling on a good road, the differential limiting force is generated due to the characteristics of the graphs 83 and 85 according to the transmitted torque, and the straight running stability of the vehicle can be improved without operating the electromagnet 87.

Even if one of the rear wheels 13 and 15 runs idle on a rough road or off-road, the driving force is sent to the other wheel by the large differential limiting force of the rear differential 7, and the running performance is kept high. Even when the idling becomes large in this way, by operating the electromagnet 87, a large differential limiting force is generated due to the characteristics of the graphs 105 and 107, and the running performance can be greatly improved. When the engagement force of the pilot clutch 69 is sufficiently large, the differential of the differential mechanism 33 is locked, and the straight running stability of the vehicle is improved. Further, if the magnetic force of the electromagnet 87 is weakened or the energization is stopped and the pilot clutch 69 is slid appropriately, the differential is allowed and smooth and stable turning can be performed.

As described above, the rear differential 7 has both torque-sensitive type torque distribution characteristics and arbitrarily controllable torque distribution characteristics, and even if the electromagnet 87 is out of order, the meshing thrust force substantially limits the differential force. Power is gained and maneuverability is maintained. Further, the coil current of the electromagnet 87 can be reduced or stopped according to the road surface condition, the steering condition, etc., so that the burden and power consumption of the electromagnet 87 can be reduced.

Next, a second embodiment will be described with reference to FIGS. The first embodiment is configured to engage a part of the pilot clutch 69 by the mesh thrust force of the gear, whereas the second embodiment is configured to engage the entire pilot clutch by the mesh thrust force. It is configured in. In this embodiment, the rear differential 10 of the vehicle shown in FIG.
9, the members having the same functions as those in FIG. 1 are designated by the same reference numerals in FIG. 3, and description thereof will be omitted. The left and right directions are the left and right directions in FIG.

Inside the differential case 21, a bevel gear type differential mechanism 33, main clutches 51, 53, a ball cam 55 and the like are arranged.

A multi-plate pilot clutch 1 is provided between the cam ring 59 of the ball cam 55 and the right side gear 41.
11 are arranged. A ring-shaped pressing member 113 is provided between the pilot clutch 111 and the right side gear 41.
Are arranged. The pressing member 113 receives the meshing thrust force of the right side gear 41 and receives the pilot clutch 1
11 is pressed and fastened. An electromagnet 87 that attracts the armature 95 and engages the pilot clutch 111 is arranged outside the differential case 21.

Since the differential limiting force due to the meshing thrust force is applied to the entire pilot clutch 111, the broken line graph 11 having a larger gradient than the graphs 83 and 85 of the first embodiment.
5, 117 torque distribution characteristics are obtained, and the electromagnet 8
When the differential limiting force by 7 is added, the broken line graphs 119, 1
A torque distribution characteristic such as 21 is obtained.

Thus, in the rear differential 109, the electromagnet 87
Is not used or the electromagnet 87 is in a bad condition,
A larger differential limiting force than that of the rear differential 7 can be obtained, so that the maneuverability is kept high and the burden on the electromagnet 87 and the power consumption can be greatly reduced. In the present invention, the friction clutch may be engaged by the mesh thrust force of the planetary gear type differential mechanism composed of a helical gear. The pressing means of the friction clutch is not limited to the electromagnet, but may be a hydraulic actuator, for example. Also, especially the second
When the entire friction clutch is pressed by the meshing thrust force as in the embodiment, the friction clutch may be directly pressed by the gear without interposing the pressing member.

[0026]

The differential device of the present invention uses a differential gear mechanism that can obtain the mesh thrust force of the differential gear, and the differential limiting clutch is engaged by this mesh thrust force in addition to the pressing means. With this configuration, it is possible to obtain both a differential limiting characteristic that can be arbitrarily controlled and a torque sensitive differential limiting characteristic. Further, even if the pressing means is out of order, a sufficient differential limiting force can be obtained to maintain operability and reduce the load on the pressing means.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment.

FIG. 2 is a torque distribution characteristic diagram of each embodiment.

FIG. 3 is a sectional view of a second embodiment.

FIG. 4 is a skeleton mechanism diagram showing a power system of a vehicle using each embodiment.

FIG. 5 is a cross-sectional view of a conventional example.

FIG. 6 is a torque distribution characteristic diagram of a conventional example.

[Explanation of symbols]

 7,109 Rear differential (differential device) 33 Differential gear mechanism 37 Pinion gear (differential gear) 39,41 Side gear (differential gear) 69,111 Pilot clutch (friction clutch) 87 Electromagnet (pressing means)

Claims (1)

[Claims] 1. A differential gear mechanism for generating a thrust force by meshing of differential gears, a differential limiting friction clutch, and pressing means for pressing the friction clutch to adjust the differential limiting force. A differential device comprising a friction clutch configured to be engaged by receiving the thrust force.