JPH04321849A - Differential gear - Google Patents

Abstract

PURPOSE:To increase the speed of operational response and to provide a center differential function with a differential limiting device by connecting a frictional main clutch for interrupting the input torque to a differential mechanism by a cam differential-operating through a frictional pilot clutch. CONSTITUTION:When an armature 101 is attracted to an electromagnet 105, a pilot clutch 99 is pressed between the armature and the right wall 93 and connected so that a cam ring 87 is connected to a differential case 31. Accordingly, torque works on a cam 91 between the differential case 31 and a differential mechanism 51 to generate right and left cam thrust forces. The respective pinion carriers 65, 67 are moved to the left by the left thrust force, so that a main clutch 75 is pressed between the carrier 65 and the differential case 31 and connected. Accordingly, the differential case 31 and the differential mechanism 51 are connected to each other, so that the right and left rear wheels are rotated by the clutch force from an engine to put a vehicle in the 4WD state. At this time, the rotation of the carrier 67 is limited by the connecting force of the pilot clutch 99.

Description

[Detailed description of the invention]

0001

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

0002

2. Description of the Related Art A "differential device" is described in Japanese Patent Publication No. 2-31259. This is a differential device equipped with a mechanism for intermittent input torque. This device is used on the front or rear wheels of a part-time four-wheel drive (4WD) vehicle to be disconnected, and the disconnection mechanism disconnects the differential device from the engine side to put the vehicle into a two-wheel drive (2WD) state.

0003

[Problems to be Solved by the Invention] In the above-mentioned device, the differential device is housed in a rotating case that is rotationally driven by the engine, and a dog clutch made of splines is disposed between the differential case and this rotating case to provide intermittent and intermittent operation. It constitutes a mechanism.

However, with dog clutches, the spline teeth are difficult to come out due to the application of torque during 4WD driving, and switching to 2WD may not be smooth. Furthermore, unless the phases of the spline teeth are matched, switching to 4WD cannot be performed smoothly. Furthermore, the dog clutch only has the function of switching between 2WD and 4WD, and cannot adjust the torque distribution ratio between the front wheels and the rear wheels and the differential limiting force between the front and rear wheels.

[0005] Accordingly, the present invention provides smooth intermittent input regardless of whether it is rotating or stationary, and also enables part-time 4
The purpose of the present invention is to provide an axle differential device capable of adjusting the torque distribution ratio and differential limiting force between the front and rear wheels of a WD vehicle.

[0006]

[Means for Solving the Problems] The differential device of the present invention is a friction-type differential device that connects a differential case rotationally driven by an engine, a differential mechanism disposed on an axle, and an input member of the differential mechanism and the differential case. A main clutch, a friction-type pilot clutch that is externally operated, and a cam that receives torque and engages the main clutch by cam force when the pilot clutch is engaged.

[0007]

[Operation] When the pilot clutch is engaged, torque is applied to the cam and the main clutch is engaged. The differential mechanism is connected to the differential case and rotationally driven by these fastening forces. Since each clutch is a friction clutch, it is possible to adjust the engagement force of the pilot clutch and change the engagement force of the main clutch via the cam. When the pilot clutch is released, the main clutch is also released. In this way, it is possible to intermittent the input and adjust the input torque, and in a part-time 4WD vehicle, it is possible to switch between 4WD and 2WD, and adjust the torque distribution ratio between the front and rear wheels and the differential limiting force between the front and rear wheels. If the pilot clutch is disposed between the differential mechanism and the differential case via a cam, a differential limiting force for the differential mechanism can be obtained.

[0008] Since each clutch has no meshing portion, input can be smoothly connected and connected with a quick response regardless of whether the clutch is rotating or stationary.

[0009]

[Embodiment] A first embodiment will be explained with reference to FIGS. 1 to 3.

FIG. 1 shows the differential device of this embodiment, and FIG. 3 shows the power system of a part-time 4WD vehicle using this device. Below, the left and right directions are for this vehicle and Figure 1.
, and the left and right directions in FIG. 2, and the upper part of FIGS. 1 and 2 corresponds to the front of this vehicle (the upper part of FIG. 3). It should be noted that members without reference numerals are not shown.

First, the configuration of this power system will be explained with reference to FIG.

This power system includes an engine 1, a transmission 3, a front differential 5 (a differential device for the front wheels), front axles 7 and 9, left and right front wheels 11 and 13, a transfer 15, a propeller shaft 17, and a rear differential 19 (a differential for the rear wheels). The vehicle is comprised of a differential device (disposed on the side), rear axles 21 and 23, left and right rear wheels 25 and 27, and the like.

The driving force of the engine 1 is input to the front differential 5 via the transmission 3 and is dividedly output to the left and right front wheels, and is also transmitted from the differential case 29 of the front differential 5 via the transfer 15 to rotate the propeller shaft 17.

Next, the rear differential 19 will be explained.

A differential case 31 of the rear differential 19 is supported within a differential carrier 33 via bearings 35, 35. The ring gear 37 is attached to the differential case 31 with bolts 39
This gear 37 meshes with a drive pinion gear 41. This gear 41 is integrally formed at the rear end of the drive pinion shaft 43. The shaft 43 is supported by the differential carrier 33 by a front bearing and a rear bearing 45, and is connected to the propeller shaft 17 at the front end.

In this way, the differential case 31 is rotationally driven by the driving force from the engine 1.

Inside the differential case 31 are left and right hubs 47.
, 49 are arranged coaxially. The left hub 47 is splined to the left rear axle 21 and the right hub 49 is splined to the right rear axle 23.

Further, a planetary gear type differential mechanism 51 is arranged inside the differential case 31. Differential mechanism 5
1 is an internal gear 53 (input member), an outer pinion gear 55, and an inner pinion gear 5 that mesh in this order.
7. It is equipped with a sun gear 59.

The internal gear 53 is rotatably supported on the inner periphery of the differential case 31. A sun gear 59 is formed on the left hub 47. The outer and inner pinion gears 55, 57 are rotatably supported on respective pinion shafts 61, 63.

Each pinion shaft 61, 63 is supported at both ends by left and right pinion carriers 65, 67. These carriers 65, 67 are welded together, and the right carrier 67 is formed integrally with the right hub 49. A washer 69 is arranged between each pinion gear 55, 57 and carrier 65, 67.

In this way, the differential mechanism 51 is constructed, and the rotation of the internal gear 53 is controlled by the pinion gears 55, 5.
7 into a sun gear 59 (hub 47) and pinion carriers 65, 67 (hub 49).
9 to the left and right rear wheels 25, 27, respectively, and when a difference in drive resistance occurs between the rear wheels, the pinion gear 5
Due to the rotation and revolution of 5 and 57, differential distribution is made between the left and right sides.

A clutch drum 71 is integrally formed at the left end of the internal gear 53, and a multi-plate main clutch 75 is disposed between the drum 71 and the cylindrical portion 73 of the differential case 31. A washer 79 is arranged between the clutch 75 and the left side wall 77 of the differential case 31.

The differential case 31 is provided with openings 81 and 83, and the oil sealed in the differential carrier 33 flows in and out through these openings 81 and 83 to lubricate the interior of the differential case 31. Note that the claw 85 of the washer 79 is folded into the opening 81 of the left side wall 77.

A cam ring 87 is arranged on the right side of the pinion carrier 67. As shown in FIG. 2, a cam 91 is formed between the pinion carrier 67 and the cam ring 87 via a ball 89. A needle bearing 95 and a washer 97 are arranged from the left between the cam ring 87 and the right side wall 93 of the differential case 31.

A multi-disc pilot clutch 99 is disposed between the cam ring 87 and the differential case 31 to connect them. Armature 1 is on the left side of clutch 99.
01 is arranged and splined to the cam ring 87 at its inner periphery. A retaining ring 103 is attached to the inner circumference of the differential case 31 to prevent contact between the cam ring 87 and the pinion carrier 67.

On the right side of the right side wall 93 is a ring-shaped electromagnet 1.
05 is placed. Electromagnet 105 is bearing 10
It is supported by the right boss portion 109 of the differential case 31 via the pins 7 and 107, and is fixed to the differential carrier 33 via the support member 111. An electromagnet 105 is installed on the right side wall 93.
A non-magnetic ring 113 is embedded in order to prevent short-circuiting of the magnetic force.

When the armature 101 is attracted by the electromagnet 105, the pilot clutch 99 is pressed against the right side wall 93 and is engaged, and the cam ring 87 is connected to the differential case 31 via the clutch 99. Therefore, differential case 3
Torque acts on the cam 91 between 1 and the differential mechanism 51,
As shown in FIG. 2, the left and right cam thrust forces 115, 11
7 occurs. The left thrust force 115 causes the pinion carriers 65, 67 to move to the left, and the main clutch 75 is pressed between the carrier 65 and the differential case 31 (washer 79) to be engaged. Note that the right thrust force 117 is applied to the differential case 31 via a bearing 95 and a washer 97.
, which is offset by the left thrust force 115.

In this way, the differential case 31 and the differential mechanism 51
is connected by a pilot clutch 99 and a main clutch 75, and the left and right rear wheels 25, 27 are rotationally driven by the driving force from the engine 1 via the differential mechanism 51, and the vehicle
It becomes WD state.

The pilot clutch 9 is operated by the electromagnet 105.
9 is strongly tightened so that a large torque is applied to the cam 91,
When the main clutch 75 is locked by the thrust force 115, the torque distribution ratio between the front and rear wheels becomes a constant value (for example, 1:1) according to the gear ratio of each power transmission system. Due to the boosting function of the cam 91, the clutch 75 can obtain a sufficiently large torque capacity even though it is small.

When the attraction force of the electromagnet 105 is weakened, the thrust force 115 becomes smaller due to the slippage of the clutch 99, the engagement force of the clutch 75 becomes smaller, and the torque distributed to the rear wheels becomes smaller. These distributed torques become smaller as the engagement force of the clutch 99 is weakened, and become maximum when the engagement force of the clutch 99 is strengthened and the clutch 75 is locked. When the clutch 99 is released, the clutch 75 is also released, the rear wheels are separated, and the vehicle enters the front wheel drive 2WD state.

[0031] The pilot clutch 99 also has a cam 91
Since it is disposed between the pinion carrier 67 and the differential case 31 via the
7 is restricted, and the differential of the differential mechanism 51 is restricted. This differential limiting force increases as the engagement force of the clutch 99 becomes stronger (as described above, in this case, the engagement force of the clutch 75 also increases).

[0032] In this way, the rear differential 19 causes the vehicle to operate at 4W.
It is possible to switch between D and 2WD, and to continuously adjust the torque distributed to the rear wheels between the maximum and minimum (in 2WD). In addition to such a center differential function, the rear differential 19 also has a differential limiting function between the rear wheels 25 and 27. Further, unlike the conventional example, the rear differential 19 does not need to be made into a double case, so the structure is simpler, smaller, and lighter.

The above-mentioned torque distribution and differential limiting force adjustment by the electromagnet 105 are automatically operated by a controller according to road surface conditions, vehicle steering conditions, and the like.

[0034] In this way, the rear differential 19 is constructed.

In the vehicle shown in FIG. 3, when the front wheels 11 and 13 idle while running in 2WD, the rear differential 19 is connected, and the rear wheels 25 and 27 are driven to enter the 4WD state, thereby maintaining all-terrain performance. During 4WD driving, if one of the front and rear wheels spins, the driving force of the other wheel maintains the vehicle's ability to travel across the country. Further, when one of the rear wheels 25, 27 is idling, the differential limiting function between the rear wheels by the rear differential 19 sends driving force to the other rear wheel, thereby maintaining running performance.

When the engagement force of each clutch of the rear differential 19 is strengthened, the straight-line stability of the vehicle is improved by limiting the differential between the front and rear wheels and between the rear wheels. When this clutch engagement force is weakened, differential movement between the front and rear wheels and between the rear wheels is allowed, allowing smooth turning and preventing tight corner braking.

As mentioned above, unlike the conventional example, the operation of the rear differential 19 is smooth and the operation response is quick regardless of whether it is rotating or stationary, so the vehicle can adjust the required torque distribution ratio and differential at the required timing. Limiting force is obtained, improving maneuverability and safety.

Furthermore, since the rear differential 19 is small and lightweight and has a center differential function, it is possible to easily configure a vehicle with a center differential function without using a special center differential, reducing the weight of the vehicle. can.

Next, the second embodiment will be explained with reference to FIG. In FIG. 4, members having the same functions as those in the first embodiment are given the same numbers. Hereinafter, the left and right directions are the left and right directions in FIG. 4, and will be described with reference to members common to the first embodiment.

A multi-plate main clutch 119 is disposed between the differential case 31 (cylindrical portion 73) and the internal gear 53 (clutch drum 71). clutch 1
Internal gear 53 and sun gear 121 are on the right side of 19.
A multi-plate clutch 123 is arranged between the two. These clutches 119 and 123 are the pilot clutch 9
When 9 is fastened, the gust force 115 of the cam 91 causes the fastening.

The clutch 123 strengthens the differential limiting force of the differential mechanism 51 in addition to the pilot clutch 99. By changing the torque capacity ratio of each clutch 119, 123, it is possible to change the ratio between the torque distributed to the rear wheels 25, 27 (differential limiting force between the front and rear wheels) and the differential limiting force between the rear wheels. .

[0042]

Effects of the Invention The differential device of the present invention is configured such that the friction type main clutch, which intermittents the input torque to the differential mechanism, is engaged by the cam that is differentially operated via the friction type pilot clutch. It operates smoothly and has a quick operational response regardless of whether it is at rest or when it is stationary, and although it is an axle differential, it also has a center differential function with a differential limiting device. Therefore, the power system of the vehicle can be configured simply, the weight of the vehicle can be reduced, and the operability can be improved.

[Brief explanation of drawings]

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

FIG. 2 is a sectional view taken along line AA in FIG. 1;

FIG. 3 is a skeleton mechanism diagram showing a power system of a vehicle using the device of FIG. 1;

FIG. 4 is a sectional view showing essential parts of a second embodiment.

[Explanation of symbols]

1 Engine 31 Differential case 53 Internal gear 75,119 Main clutch 91 Cam 99 Pilot clutch

Claims (1)

[Claims] Claim 1: A differential case rotationally driven by an engine, a differential mechanism disposed on an axle, a friction type main clutch connecting an input member of the differential mechanism and the differential case, and an externally operated friction type main clutch. pilot clutch and
A differential device comprising: a cam that receives torque when a pilot clutch is engaged and engages a main clutch using cam force.