JPH0451696B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a differential limiting device disposed, for example, between rear wheel axles of an automobile.

(b) Technical background and problems Conventionally, limited slip differential gears (hereinafter abbreviated as LSD) as shown in Fig. 5 have been used.
is known, and its configuration includes a ring gear 101 that meshes with a drive pinion (not shown).
differential case 103 fixed with
A side gear 11 provided inside the case 103 and connected to axles 113, 113 connected to wheels.
1,111, a pinion gear 109 that meshes with the side gears 111, 111, a pinion shaft 107 provided with the same gear 109, and the same shaft 10.
pressure rings 102, 102 disposed on both sides of the differential case 103 and fitted to the differential case 103 so as to be slidable in the axial direction;
2,102 and the differential case 10
3 and a clutch disk 115 that operates integrally with the side gear 111, and a clutch plate 117 that operates integrally with the differential case 103. Ta.

Therefore, the action of the conventionally structured LSD will be explained.
Regarding torque transmission during driving, when the differential case 103 is rotated by the drive pinion via the ring gear 101, the pressure rings 102, 102 which are fixed in the rotational direction
rotates at the same speed as the differential case 103. Since the rings 102, 102 and the pinion shaft 107 are made to match, the pinion shaft 107 rotates as the pressure rings 102, 102 rotate, and during this rotation, the pinion shaft 107 rotates. Tushiya ring 10
2 and 102 are pushed open left and right by the cam action of the pinion shaft 107, and the clutch disk 115 and the clutch plate 117 are pressed and connected. In other words, when traveling straight, the left and right wheel resistances are equal, so the left and right side gears 111,
111 becomes equal, and the movement of pinion gear 109 is controlled by differential case 103.
revolves around the axle at the same speed as the side gear 11.
There is no relative speed between the drive pinion and the ring gear 10.
1 → Differential case 103 → Pressure ring 102, 102 → Pinion shaft 1
07 → pinion gear 109 → side gear 111,
Torque is evenly transmitted in the order of 111→axle. Also, when there is a rotation difference between the left and right wheels, the torque is divided equally between the left and right wheels as when driving straight, but the torque transmitted to the high-speed wheel is equal to the road resistance of the same wheel. Since only torque is applied to the axle, the torque transmission state is obtained by subtracting the clutch capacity. In other words, the torque appearing on the high-speed wheel side is not affected by the clutch resistance, but since this clutch resistance has a braking effect, it is transmitted to the side gear 111 on the low-speed wheel side via the differential case 103. is,
The torque transmitted to the low-speed wheels is added by clutch resistance.

However, in such a conventional differential limiting device, the differential is limited by the frictional force of the multi-disc clutch 119, so if the multi-disc clutch 119 slips, abnormal noise may be generated. There is a problem in that this abnormal noise gives a sense of discomfort and anxiety to the driver.

(c) Purpose of the Invention The present invention was devised in view of the above-mentioned problems, and an object of the present invention is to provide a differential limiting device that generates less abnormal noise.

(d) Structure of the Invention In order to achieve the above object, the present invention includes a pinion gear rotatably supported via a pinion shaft in a differential case that is interlocked with the drive side and rotationally driven; In a differential device having a pair of side gears meshing with the pinion gear, a pair of cams each having a cam surface are provided on the pair of side gears to rotate in conjunction with each other, and a pair of left and right plungers communicate with the cam surface via an orifice. A sleeve having a fitting hole is provided, and a pair of plungers whose tips are engaged with the cam surface are slidably fitted into the plunger fitting hole of the sleeve, and a fluid is stored inside. The cam surface is formed to cause the pair of plungers to reciprocate synchronously in the same direction during differential rotation of the side gears.

(e) Embodiment Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 is a cross-sectional view of a differential limiting device according to the present invention, in which a ring gear (not shown) that is interlocked with a drive pinion (not shown) on the drive side is fixed to a differential case 1, so that the ring gear and the differential case 1 rotate together.

On the other hand, a pair of pinion gears 5 are rotatably attached to the pinion shaft 3. A side gear 7 serving as a pair of output gears meshing with the pinion gear 5 is rotatably disposed within the differential case 1. The side gear 7 is operatively connected to an axle 9 that is connected to a wheel (not shown) through spline fitting.

An annular cam 11 is supported by the side gear 7 so as to be movable in the axial direction and engageable in the rotational direction, and the cam 11 rotates together with the side gear 7. On the front side of this cam 11, there is a second
As shown in the figure, a cam surface 11a is formed. The cam 11 is fixed to the side gear 7 with the phases of the opposing cam surfaces 11a appropriately shifted, so that the spacing between the opposing cam surfaces 11a is always constant when the side gear 7 is differentially operated. Further, a thrust ring 13 is provided in the differential case 1 as a thrust bearing for the pinion gear 5 and the side gear 7.

A sleeve 15 is disposed between the cams 11. The sleeve 15 has an orifice 17 formed in its center, and a pair of left and right plunger fitting holes 19 communicating through the orifice 17. Although not shown, a plurality of plunger fitting holes 19 are provided in the circumferential direction. However, it can also be made single in the circumferential direction. Each plunger fitting hole 19 has a plunger 21
are fitted airtightly and slidably through an oil seal 23. This plunger 21 is
As shown in FIG. 3, it has an oil storage hole 25. The tip of the plunger 21 is
is engaged with the cam surface 11a of the cam 11,
It is configured to slide as the cam 11 rotates.

A fluid 27 such as silicone oil is stored in the plunger fitting hole 19 .

Next, the effect will be explained.

In substantially the same manner as in the conventional example, the differential case 1 is rotated by the rotation of a ring gear (not shown) connected to the drive side. When the differential case 1 rotates, the pinion shaft 3, pinion gear 5, side gear 7, cam 11, sleeve 15, etc. inside the differential case 1 also rotate integrally, so they are interlocked and connected to the side gear 7. The axle 9 and wheels (not shown) connected to the axle 9 also rotate.

If the wheel on one axle 9 side slips due to falling into muddy ground, etc., the axle 9 on the side that slipped will
The side gear 7 connected to the differential case 1 begins to rotate relative to the differential case 1, and the pinion gear 5 also rotates relative to the pinion shaft 3. This rotation of the side gear 7 causes the cam 11 to rotate together. Due to the rotation of this cam 11, the cam 1
A pair of plungers 21 that are in contact with one cam surface 11a slide in synchronization with respect to the sleeve 15 in the same direction. When the relative speed difference between the side gears 7 exceeds a certain value, as shown in FIG. 4, the resistance generated when the internal fluid 27 passes through the orifice 17 due to the sliding movement of the plunger 21 increases. Thus, the plunger 21 applies braking to the side gear 7 via the cam 11 to limit the differential movement.

In this way, by differentially limiting the wheel (not shown) on the slipping side, driving force can be transmitted to the wheel (not shown) on the other side, making it easier to escape from a rough road.

(F) Effects of the Invention As is clear from the above explanation, according to the configuration of the present invention, the differential is limited by using fluid resistance, and unlike the conventional method, the differential is limited by frictional force. Therefore, there is little chance of abnormal noises caused by the sliding of the friction plates.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a sectional view of a differential limiting device according to the invention, FIG. 2 is an enlarged perspective view of the cam of FIG. 1, and FIG. 3 is an enlarged perspective view of the cam of FIG. An enlarged sectional view of the main part of Figure 1, Figure 4 is a diagram showing the relationship between orifice resistance and differential rotation speed,
FIG. 5 is a sectional view of a conventional differential limiting device. Explanation of symbols representing main parts of the drawings: 1...Differential case, 3...Pinion shaft, 5...Pinion gear, 7...Side gear, 11...
Cam, 11a...Cam surface, 15...Sleeve, 17...
Orifice, 19...Plunger fitting hole, 21...Plunger, 27...Fluid (silicone oil).

Claims (1)

[Claims] 1. In a differential device that includes a pinion gear that is rotatably supported via a pinion shaft in a differential case that is connected to the drive side and is rotationally driven, and a pair of side gears that mesh with the pinion gear. A pair of cams having cam surfaces are provided on the pair of side gears so as to rotate in conjunction with each other, and a sleeve is provided between the cams in which a pair of left and right plunger fitting holes are formed and communicated through an orifice. A pair of plungers whose tips are in contact with the cam surface are slidably fitted into the plunger fitting hole, and a fluid is stored inside, so that the cam surface is connected to the pair of plungers during differential rotation of the side gears. A differential limiting device characterized in that a plunger is formed to reciprocate in synchronization in the same direction.