JPH0517483Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an improvement of a differential limiting device used in vehicles and the like.

[Technical Background and Problems] Conventional differential limiting devices include a differential gear mechanism that uses a pair of side gears that mesh with a pinion gear in a differential case, and a differential gear mechanism that uses a pair of side gears that engage with a pinion gear in a differential case, and a Many of them are constructed from a multi-plate clutch mechanism that is equipped with a multi-plate clutch mechanism and acts as a differential limiting means. In order to improve the engagement characteristics, that is, the differential limiting characteristics, of the multi-disc clutch mechanism, there is a system in which a preload spring is disposed within the differential case so as to act on the clutch plates of the multi-disc clutch mechanism. For example, Utsukai Showa 59-17352
As disclosed in Japanese Patent Publication No. 51-35976, a disc spring interposed in the clutch plate part, or a pair of disc springs as disclosed in Japanese Utility Model Publication No. 56-34192, This is a coil spring installed in the center of the side gear facing each other. By preloading the multi-plate clutch mechanism with these preload springs, an initial torque is provided in the differential limiting characteristic.

However, all of these preload springs have drawbacks. In other words, in the former case, when the axial thrust generated by the cam mechanism near the center of the differential case increases, the pressure ring expands outward against the reaction force of the disc spring. On the other hand, the spring reaction force acts as a loss. Also, when the pressure ring moves in the axial direction by this cam mechanism, a gap is created between the side gear and the pressure ring, and the side gear can move freely in the axial direction, increasing the looseness of the engagement between the side gear and the pinion gear, causing backlash. There is a problem that it is easy to generate abnormal noise due to In the latter case, the spring applies a biasing force in the direction of disengaging each side gear from the pinion gear, so when the side gear moves due to the axial thrust at the time of differential, the collision between the side gear and the pinion gear increases, and as above, There is a problem in that it tends to generate abnormal noise. Furthermore, in the latter case, since the biasing force of the spring always acts in a direction to disengage the side gear and the pinion gear, there is a problem that it is difficult to adjust the backlash of each gear during assembly.

[Purpose of the invention] This invention was devised in view of the above-mentioned problems, and while improving the efficiency of the differential limiting characteristic, it also reduces the occurrence of rattling in the engagement between the pinion gear and the side gear, and improves the It is an object of the present invention to provide a differential limiting device that can easily adjust the backlash.

[Structure of the invention] In order to achieve the above object, this invention includes an annular pressure ring that engages with the differential case in the rotational direction and is movable in the direction of the rotational axis; A pinion shaft provided therein, a pair of side gears that mesh with a pinion gear that is rotatably supported by the pinion shaft, and a pair of side gears that are arranged between the preshear ring and the differential case, and are arranged between the preshear ring and the differential case. a multi-plate clutch-type limiting means that is fastened to limit differential movement between the side gear and the differential case; and a rotation input from the differential case that is provided between the inner end of the pressure ring and the pinion shaft. A cam means is interposed between the back surfaces of the side gear and the pressure ring to move the pressure ring in the axial direction and actuate the limiting means, and urges the side gear toward the pinion shaft and moves the pressure ring into the above-mentioned direction. The structure includes an elastic body in the form of a disc spring that biases the restricting means in the direction of activation.

[Embodiment of the invention] An embodiment of the invention will be described below based on FIG. 1.

A ring gear (not shown) is attached to the outer periphery of the differential case 1, and the differential case 1 is rotated by being driven by an input from an engine (not shown). A pinion shaft 3 is disposed near the center of the differential case 1, perpendicular to the rotational axis of the differential case 1. A pinion gear 5 is rotatably fitted into and supported by the pinion shaft 3. A pair of side gears 7a and 7b that mesh with the pinion gear 5 are disposed on both sides of the pinion gear 5.

The side gears 7a and 7b have output shafts 9a and 9, respectively.
b is inserted into each wheel, and transmits the driving force to each wheel (not shown), and due to the rotation of the engagement between the side gears 7a and 7b and the pinion gear 5, both output shafts 9
The differential rotation occurring between a and 9b is absorbed. Multi-plate clutch mechanisms 15a, 1 are constructed of pressure rings 11a, 11b and a plurality of clutch plates 13 between the boss outer periphery of side gears 7a, 7b and the inner periphery of differential case 1.
5b is interposed as a limiting means for limiting the differential rotation. Pressure rings 11a, 11b
The cam means 17 is configured such that one end (inner end) pinches the end of the pinion shaft 3 from both sides,
The outer surface of the other end is in contact with the clutch plate 13, and the lower half is an annular member with an L-shaped cross section. The plurality of clutch plates 13 are arranged in spline engagement with the inner peripheral surface of the differential case 1 and the outer peripheral surfaces of the bosses of the side gears 7a and 7b alternately, and are movable in the axial direction. , 11b and the pinion shaft 3 actuate the cam means 17 to rotate the pressure ring 1.
When 1a and 11b move in the axial direction, the multi-plate clutch mechanisms 15a and 15b are pressed, and the differential case 1 and the side gears 7a and 7b are engaged to limit the differential rotation between the output shafts 9a and 9b. It acts on Furthermore, side gear 7
The back surface of the teeth of a, 7b and the pressure ring 11a,
Disc springs 19a and 19b are interposed as elastic bodies in the space between the back surface of the spring 11b and the back surface of the spring 11b. Belleville spring 19
The spring reaction forces of a and 19b direct the side gears 7a and 7b toward the pinion gear 5, and the pressure ring 1
1a and 11b are multi-plate clutch mechanisms 15a and 15b.
It is configured so that it faces in the direction of fastening.

The differential device of this invention is constructed as described above and operates as follows.

The disc springs 19a, 19b interposed between the pressure rings 11a, 11b of the multi-plate clutch mechanisms 15a, 15b and the side gears 7a, 7b first act on the multi-plate clutch mechanism due to the action of the spring reaction force as described above. It acts as a preload spring that applies pressure extremely uniformly over the entire surface of the clutch plates 15a and 15b, and applies a predetermined fastening force to the multi-plate clutch mechanisms 15a and 15b from the beginning of the differential rotation of both side gears 7a and 7b. It has the function of improving the rise of the differential limiting characteristic and raising the level of this acting force as a whole. Due to this function, even when the vehicle suddenly starts, the clutch plate 13 quickly limits the differential movement, and it is possible to prevent the phenomenon of tail wobbling and the like.

The differential between the two output shafts when the vehicle travels around a curve or the like is absorbed by the rotation of the mesh between the side gears 7a, 7b and the pinion gear 5. Furthermore, if the differential between both output shafts (both wheels) becomes large during spin, such as when getting stuck in mud, the pressure ring 11a,
11b move axially outward through the cam means 17 by relative rotation with the pinion shaft 3, bringing the clutch plates 13 into contact with each other to perform a differential limiting action. At this time, since the pressing force of the pressure rings 11a, 11b by the cam means 17 is in the same direction as the biasing force of the disc springs 19a, 19b, the pressing force of the cam means can be reduced accordingly, and therefore the cam The strength of the pressing portion can also be reduced accordingly.

Figure 2 shows the performance curve and cam angle θ of the cam means for reference when the horizontal axis is the spin side wheel torque and the vertical axis is the lock side wheel torque, and the dotted line Z indicates no differential limiting device. conventional differential,
The polygonal line Y shows the differential with a conventional differential limiting device (Japanese Patent Publication No. 51-35976), and the straight line X shows the differential with this invented device, where the intersection point A is the maximum torque required. As can be seen from this figure, the straight line X of this invention is more advantageous than the conventional polygonal line Y, which resists the preload spring and limits the differential, as the torque on the locking side is increased. Therefore, in this invention, the cam angle θ as the pressing portion of the cam can be reduced, the amount of movement on the cam surface can be reduced, and wear can also be reduced.

Furthermore, since the pressing force of the disc springs 19a and 19b is acting in a direction that brings the tooth surfaces of the side gears 7a and 7b closer to the pinion gear 3 side from behind, respectively, the thrust generated by the torque transmission of these two gears is It acts to counteract the tendency of the side gears 7a, 7b to separate from the pinion gear 3 and eliminate bumps when the two gears mesh, thereby preventing noise and vibrations that occur when the bumps are excessively high, thereby preventing abnormal wear of these gears. These effects can be maintained even if the clutch plate 13 is worn to some extent. At the same time, the adjustment of the buckle is also made in accordance with the biasing force of the disc spring, which makes it that much easier.

[Effects of the invention] As is clear from the above, according to the configuration of this invention, the elastic body that applies preload to the limiting means is interposed between the side gear and the pressure ring, and is biased in the direction of separating them. By deciding to do so,
It acts as a sensitive and direct preload force, exhibiting an effective differential limiting function, and suppresses rattling of the side gear and pinion gear without being affected by the magnitude of the axial thrust on the limiting means or the wear of the clutch plate, reducing noise. This has the effect of being able to prevent vibration for a long period of time and also making it easy to adjust the backlash.

[Brief explanation of drawings]

FIG. 1 is a schematic longitudinal cross-sectional view of the differential limiting device according to this invention, and FIG. 2 is a performance diagram showing the torque relationship during spin and a reference diagram of the cam angle. Explanation of main drawing symbols, 1... differential case, 3... pinion shaft, 5... pinion gear, 7... side gear, 11... pressure ring, 15... multi-plate clutch mechanism (limiting means) , 17...cam means, 19... disc spring (elastic body).

Claims (1)

[Scope of utility model registration request] an annular pressure ring that engages with the differential case in the rotational direction and is movable in the direction of the rotational axis; a pinion shaft that is disposed on the differential case; and a pinion shaft that is rotatably supported by the pinion shaft. a pair of side gears that mesh with the pinion gears, and a multi-wheel drive gear that is disposed between the pressure ring and the differential case and is fastened by the axial movement of the pressure ring to limit the differential movement between the side gears and the differential case. a plate clutch type limiting means; and a cam provided between the inner end of the pressure ring and the pinion shaft to move the pressure ring in the axial direction by rotational input from the differential case and actuate the limiting means. and a disc spring-like elastic body interposed between the back surfaces of the side gear and the pressure ring, which urges the side gear toward the pinion shaft and urges the pressure ring in a direction that activates the limiting means. A differential limiting device characterized by being provided.