JP3742309B2 - Limited slip differential gear - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a limited slip differential gear, and in particular, a differential limiting function and a differential locking state in which the differential function is locked and the driving force from the engine is transmitted to the drive wheels can be selected with a simple operation. This relates to the slip differential gear.
[0002]
[Prior art]
An example of a limited slip differential gear (hereinafter abbreviated as LSD) is disclosed in Japanese Patent Laid-Open No. 62-062040. As shown in FIG. 5 and FIG. 6, when the rotational driving force in the forward direction is transmitted from the engine side, the LSD starts to work with differential restriction, but the rotational driving force is transmitted from the driving wheel side. In this case, the differential case 1 is of a type that does not have a differential restriction, and is opposed to each other in the case 1 so as to be movable in the axial direction of the axles 10 and 11 of the drive wheels and the differential case 1 that rotates by the driving force from the engine A pair of pressure rings 2 and 3, a pinion shaft (formed in a cross shape) 4 that is sandwiched between the pair of pressure rings 2 and 3 and rotates integrally with the case 1, and the shaft 4 The pinion gear 5 rotatably attached to the tip of the pinion and the pinion gear 5 are arranged so as to sandwich the pinion gear 5 from both sides, and mesh with the pinion gear 5 to drive the axle. A pair of side gears 6, 7 for transmission, and provided between the case 1 and the side gears 6, 7, and are pressure-bonded by the outward movement of the pressure rings 2, 3 in the axle direction. And the multi-plate friction clutches 8 and 9 for limiting the differential between them, and the pressure rings 2 and 3 are respectively moved outwardly of the axles to widen the gap between them. In order to crimp each, the shaft cross-section of the pinion shaft 4 is formed in a substantially D shape, and the pressure rings 2 and 3 are formed with cam surfaces that engage with the shaft portion of the pinion shaft 4. A cam component mechanism is provided in which the notches 2a and 3a are formed symmetrically (both notches are formed into a substantially triangular shape). The multi-plate friction clutch includes a plurality of clutch plates (inner claws) that are movably fitted in an axially engaged groove that is formed in a shaft portion of the side gear and extends in the axial direction, and an inner periphery of the case 1. A plurality of clutch plates (outer claws) that engage with axially formed grooves formed on the surface are alternately arranged.
[0003]
When the rotational driving force in the forward direction is transmitted to the LSD by the cam component force mechanism, the pair of pressure rings 2 and 3 are pushed and spread by the pinion shaft 4 that rotates integrally with the case 1 so that the differential restriction is effective. When a rotational driving force is transmitted from the driving wheel side when the engine brake is operated during forward traveling, the pair of pressure rings 2 and 3 are not spread and differential restriction is not effective. The normal differential function will operate. Of course, if the cam surface of the cam component force mechanism is formed in a diamond shape instead of the above-mentioned triangular shape, differential limitation is also exerted during forward / reverse travel.
[0004]
A ring gear 12 is fixed to the case 1, and a pinion gear 13 that transmits engine rotation is engaged with the ring gear 12. The case 1 including the ring gear 12 and the pinion gear 13 is housed in an outer case (not shown).
[0005]
[Problems to be solved by the invention]
As described above, the differential gear is usually mounted between the drive wheels so as to absorb the difference in rotation between the left and right tires when the vehicle is turning and to enable smooth turning.
[0006]
The differential gear enables smooth turning, but the tire grip is low, low μ road surfaces (rainy roads, snowy roads, unpaved roads, etc.), bad roads where one wheel is completely lifted off the road surface, etc. When driving, the driving force escapes to the tire side where the resistance to the road surface is low, driving loss occurs, and safe and stable driving cannot be performed. In some cases, it may become impossible to run.
[0007]
Therefore, in order to reliably transmit the driving force to the road surface, the above-described LSD is provided to improve the running performance on low μ road surfaces and bad roads.
[0008]
Such LSD is suitable for running on paved roads, unpaved roads, snowy roads and the like in motor sports such as rally.
[0009]
However, on rough roads such as paved roads, unpaved roads, snowy roads, etc., it is not necessary to speed up, but in the mountains, rivers, muddy roads, etc. Even a vehicle equipped with LSD may not be able to run.
[0010]
Therefore, the invention according to the present application enables traveling with the LSD function exhibited, can also travel on rough roads, and can easily obtain traveling performance and handling stability according to the situation on any road surface. It is intended to provide a limited slip differential gear.
[0011]
[Means for Solving the Problems]
A limited slip differential gear that realizes the object of the present invention includes a differential case that is rotated by a driving force from an engine, a differential carrier that is rotatably disposed inside the case, and a drive wheel that rotates integrally with the case. A pair of pressure rings accommodated in the case so as to be movable in the axle direction of each other, and a pinion gear rotatably attached to a cross-shaped pinion shaft sandwiched between the pair of pressure rings, The pinion gear is disposed so as to sandwich the pinion gear from both sides, and is provided between a pair of side gears that mesh with the pinion gear and transmit driving force to the axle of the driving wheel, and between the side wall surface of the case and the side gear, By moving the pressure ring outward in the axial direction, A multi-plate clutch that is crimped to limit the differential between the two side gears, and a cam component force mechanism that is formed on the pressure ring and the pinion shaft, and moves the pair of pressure rings outward in the axle direction away from each other; A switching mechanism that enables the side gear to be switched between a coupled state and a non-coupled state with respect to the case , an operation mechanism that operates the switching mechanism from the outside of the differential carrier, and an inner peripheral portion of the differential carrier. A limit slip differential gear having a lock nut with an outer side recessed in a recess, which rotatably supports the differential case via a bearing with respect to the differential carrier, wherein the switching mechanism is provided in the differential case. Engage with the bearing for the wheel shaft so that it can move in the axial direction and cannot rotate around the shaft, and is connected to the side gear in a non-rotatable manner by moving inward in the axial direction and with the side gear by moving outward in the axial direction. A sleeve that is rotatably mounted on the axle to be uncoupled, and a lock nut that engages with the lock nut so as to be axially movable and non-rotatable around the shaft. And a cam cylinder having a cam groove formed on the outer peripheral surface thereof that allows the sleeve to rotate and is rotatably mounted on the cam cylinder and engages with the cam groove of the cam cylinder And an operating cylinder whose inner end portion enters the outer recess of the lock nut, and the operating mechanism is rotated in the forward and reverse directions by the operating mechanism .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
1, 2, 3 and 4 show an embodiment of the present invention.
[0013]
In the present embodiment, the conventional LSD shown in FIG. 5 is improved to enable switching between an operation limiting operation state in which the LSD functions and a differential lock state in which the differential function itself is locked.
[0014]
In the present embodiment, a differential lock state is created by fixing one side gear 6 and the case 1 out of the pair of side gears 6 and 7. That is, the driving force of the engine (not shown) is transmitted to the case 1 via the pinion gear 13 and the ring gear 12, and since the case 1 and the side gear 6 are in a directly connected state, the axle 10 fixed to the side gear 6 is also in the case. 1 and a direct connection state.
Further, since both the side gear 6 and the pinion shaft 4 are fixed to the case 1, the side gear 6 and the pinion shaft 4 rotate integrally, and the other side gear 7 also rotates integrally. Will not operate, and the tires attached to the left and right axles 10 and 11 will rotate with the driving force from the case 1 regardless of the road surface condition.
[0015]
FIG. 1 is a partially cutaway cross-sectional view of an LSD including a switching mechanism that enables switching between an operation limiting operation state in which the LSD functions and a differential lock state in which the differential function itself is locked. 2 is a sectional view showing a differential limiting operation state, and FIG. 3 is a cross-sectional view showing a differential lock state.
[0016]
1, 2, and 3, the differential case 1 is rotatably mounted in a differential carrier 20 that is an outer case, and a bearing portion 1 a of the differential case 1 that pivotally supports one axle 10 has an outer periphery thereof. The portion is pivotally supported by a differential carrier 20 via a differential taper bearing 21 so as to be rotatable.
[0017]
In the present embodiment, a case spline 1b extending in the axial direction is formed in the circumferential direction on the inner peripheral surface of the bearing hole of one bearing portion 1a of the case 1.
[0018]
Further, in one side gear 6, the shaft hole to which the axle 10 is fixed has a stepped shape, the axle 10 is fixed to the small-diameter hole 6b, and the inner periphery of the outer large-diameter hole 6c is the same as the spline 1b. Side gear splines 6a are formed.
[0019]
On one bearing 1a, a sleeve spline 22a formed on the outer periphery engages with the case spline 1b and can move in the axial direction, and a sleeve 22 that rotates integrally with the case 1 is mounted around the shaft. One axle 10 is rotatably mounted in the sleeve 22.
[0020]
Therefore, in the state of FIG. 2 (shown as A in FIG. 1) in which the sleeve 22 is held in one bearing portion 1a and the tip portion does not mesh with the side gear spline 6a, the side gear 10 and the case 1 are not coupled. Therefore, the limited slip differential function, which is the characteristic of this differential gear, operates.
[0021]
Further, the sleeve 22 is moved from the state shown in FIG. 2 toward the one side gear 6, and the sleeve spline 22a of the sleeve 22 is engaged with the side gear spline 6a of the side gear 6 and splined (see FIG. 3). In B), the case 1 and one side gear 6 are integrally coupled via the sleeve 22. In the state where the side gear 6 and the case 1 are integrally coupled, as described above, the differential lock state is established.
[0022]
In order to switch the sleeve 22 in the axial direction to switch between the limited slip differential function state shown in FIG. 2 and the differential lock state shown in FIG. 3, in this embodiment, as shown in FIG. A cam cylinder 23 having a cam groove 23a formed on the outer peripheral surface at one end is attached so as not to move in the axial direction and to the center of the shaft so as not to rotate (a spline 23b formed axially on the outer peripheral surface of the cam cylinder 23 It is made non-rotatable by engaging with a spline 29b of a lock nut 29 described later). In the present embodiment, one end of the cam cylinder 23 is abutted against a stepped portion formed on the outer periphery of the sleeve 22, and the movement of the cam cylinder 23 in the axial direction is restricted by a washer 27 attached to the other end side. .
[0023]
An operating cylinder 28 is rotatably mounted on the outer periphery of the cam cylinder 23, and a cam pin 26 that engages with a cam groove 23 a of the cam cylinder 23 is attached to the operating cylinder 28.
[0024]
Therefore, when the operating cylinder 28 is rotated, the cam pin 26 traces the cam groove 23a. However, since the cam cylinder 23 is non-rotatably attached to the lock nut 29 by the spline 29b, the cam cylinder 23 is connected to the sleeve. 22 and move linearly in the axial direction with respect to the case 1. At this time, when the operation cylinder 28 is rotated counterclockwise, the cam cylinder 23 moves in the direction of the side gear 6, and conversely, when the operation cylinder 28 is rotated counterclockwise, the cam cylinder 23 moves outward in the axial direction.
[0025]
Further, in the present embodiment, the lock nut 29 that presses the tapered bearing 21 against the case 1 is formed in a shape in which the outer side is recessed in the recess, as shown in FIG. The lock nut 29 is provided on the outer periphery of the actuating cylinder 28 so as to cover a part of the actuating cylinder 28, and as shown in FIG. 4, the lock nut 29 is provided on the inner peripheral surface of the lock nut. By inserting a part of the operating cylinder 28 between the retaining ring 29a and a part of the nut, a unit in which the lock nut 29 is integrated with the cam mechanism described above is formed. The lock nut 29 is screwed into the differential carrier 20 so that the unitized cam mechanism can be attached to one end of the case 1.
[0026]
On the other hand, an operation lever 24 is provided in the driver's seat, and cables 25a and 25b are attached to the operation lever 24, respectively. The cable 25a and the cable 25b penetrate the differential carrier 20 in an oiltight state, and the distal end of the cable 25a and the distal end of the cable 25b are respectively connected to the outer periphery of the working cylinder 28 on the engaging shaft 30 attached to the working cylinder 28. It is hung on and attached from different directions.
[0027]
Therefore, when the operation lever 24 is rotated to the operating state position of the limited slip differential function indicated by the solid line, one cable 25a is pulled up to rotate the operating cylinder 28 clockwise, and the cam cylinder 23 is axially moved as described above. The sleeve 22 moves outward and the spline connection with the side gear 6 is released.
[0028]
Further, when the operation lever 24 is rotated to the differential lock position shown in FIG. 1 indicated by a dotted line, the other cable 25b is pulled up to rotate the operation cylinder 28 counterclockwise, and the cam cylinder 23 is located on the side gear 6 side as described above. The sleeve 22 is splined to the side gear 6.
[0029]
In the present embodiment, the cam mechanism is used as an example of a mechanism for coupling the side gear and the case 1, but the present invention is not limited to this.
[0030]
According to the present embodiment, by locking the differential function, which is indispensable for ensuring the stable driving performance of the automobile, the driving force from the engine is transmitted to the driving wheels without loss, and one wheel is completely It is possible to drive the left and right drive wheels even in the worst road condition where stable driving force cannot be transmitted, such as slip condition, lift condition, etc., and the limited slip differential function is possible if escape from this bad road condition By operating the operation lever 24 so as to operate the vehicle, high running performance can be obtained even on a normal rough road.
[0032]
Also, the LSD component force mechanism is not limited to that shown in FIG. 5, but may be of a type in which the LSD operates both forward and backward.
[0033]
Furthermore, an elastic member such as a spring may be disposed on the opposing surfaces of the outer peripheral portions of the pair of pressure rings so that the LSD handing degree can be adjusted.
[0034]
【The invention's effect】
According to the present invention, since the limited slip differential function has a function to lock the differential function by an arbitrary operation, both functions can be switched while driving a vehicle equipped with the limited slip differential gear. It was. As a result, it is possible to easily obtain the running performance and handling stability that suits the situation on any road surface.
[Brief description of the drawings]
FIG. 1 is a partially cutaway cross-sectional view of a limited slip differential gear showing an embodiment of the present invention.
FIG. 2 is a diagram showing an LSD function operation state which is the state of the part in FIG. 1A.
3 is a diagram showing a differential lock state that is a state of a B portion in FIG. 1. FIG. 4 is a diagram showing a cam mechanism for coupling the side gear and the case in FIG.
FIG. 5 is a cross-sectional view of a conventional limited slip differential gear.
6 is a cross-sectional view including a side gear of the limited slip differential gear of FIG. 5;
[Explanation of symbols]
1 Differential case 2, 3 Pressure ring 4 Pinion shaft 5 Pinion gear 6, 7 Side gear 8, 9 Multi-plate friction clutch 10, 11 Axle 12 Ring gear 13 Pinion gear 20 Differential carrier 22 Sleeve 23 Cam cylinder 24 Operation lever 25a, 25b Cable 26 engaging pin 27 washer 28 actuating cylinder 29 lock nut 30 engaging shaft

Claims (1)

A differential case that is rotated by a driving force from the engine, a differential carrier that is rotatably disposed inside the case, and a case that rotates integrally with the case and that is movable in the axle direction of the drive wheels. A pair of pressure rings, a pinion gear rotatably attached to a cross-shaped pinion shaft sandwiched between the pair of pressure rings, and a pinion gear arranged to sandwich the pinion gear from both sides, respectively. A pair of side gears that mesh with the pinion gear and transmit driving force to the axle of the drive wheel, and are provided between the side wall surface of the case and the side gear, and are crimped by the outward movement of the pressure ring in the axle direction. A multi-plate clutch for limiting differential between the two side gears, Formed in Tsu shirring and said pinion shaft, and the cam component force mechanism for moving the axle outwardly away from each other said pair of pressure rings, can be switched to the side gear to the coupling state and a non-binding state with respect to said casing A switching mechanism, an operating mechanism for operating the switching mechanism from the outside of the differential carrier, and an inner peripheral portion of the differential carrier that are screwed together to support the differential case rotatably with respect to the differential carrier via a bearing. In a limit slip differential gear having a lock nut whose outside is recessed in a recess,
The switching mechanism engages with the axle bearing portion provided in the differential case so as to be axially movable and non-rotatable around the shaft, and is non-rotatably coupled to the side gear by moving inward in the axial direction. And a sleeve externally mounted on the axle that is uncoupled from the side gear by moving outward in the axial direction;
An outer peripheral surface that engages with the lock nut so as to be axially movable and non-rotatable around the shaft, is externally attached to the sleeve, moves integrally with the sleeve in the axial direction, and allows the sleeve to rotate. A cam cylinder in which a cam groove is formed;
An operating cylinder that is externally rotatably mounted on the cam cylinder, includes a cam pin that engages with a cam groove of the cam cylinder, and has an inner end portion that enters into an outer recess of the lock nut, and the operation mechanism A limited slip differential gear characterized in that the operating cylinder is rotated in the forward and reverse directions by the above .

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