JPH1113854A - Limited slip differential gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a limited slip differential gear surely switching adhesion to a multi-disk friction clutch mechanism to a half-clutch condition and prevent a handle from being taken, at access on/off time of curving, turning, etc., during running at a high speed. SOLUTION: A lock part provided to protrude respectively in a first/second cam surface 52, 54 of a V-shaped groove to be formed by a first/second lock surface and a notched part hollowly provided in a part corresponding to a lock part of a pinion shaft to be formed by a first/second notched surface 40A, 40B are provided. When the lock part and the notched part are engaged, a void X is formed between the first lock surface and the first notched surface 42A, the notched part formed in the pinion shaft and a protrusion part of a pressure ring 46 are placed in a lock condition, any more press opening of the pressure ring 46 is impeded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a limited slip differential gear applied to a vehicle.

[0002]

2. Description of the Related Art Conventionally, a vehicle is provided with a limited slip differential gear so that when one wheel enters a mud or the like, the vehicle can easily escape therefrom. However, in the limited slip differential gear described above, the cam action surface formed on the pressure ring with which the cam contact surface of the pinion shaft abuts is formed linearly.

[0003] The cam contact surface of the pinion shaft pushes the pressure ring to the maximum in the axle direction via the cam action surface. As a result, the pressure ring presses the multi-plate friction clutch mechanism, and The torque from the gear case is transmitted to the side gear as much as possible. For this reason, since the torque from the differential gear case is strongly transmitted to the side gears, there is a problem that the driver can take off the steering wheel when the accelerator is off such as a curve or turning during high-speed running.

[0004]

Therefore, the present inventor has proposed:
It is noted that a so-called half-clutch state with respect to the multi-plate friction clutch mechanism can be obtained by regulating the amount of movement of the pressure ring toward the multi-plate friction clutch mechanism.
Then, the intense research was conducted in the direction of providing the lock portion for restricting the movement on the cam action surface where the pressure ring and the pinion shaft abut. The applicant has filed Japanese Utility Model Application No. 6-3398 (registration number 3001939).

Accordingly, the applicant has further studied and found that, by making an angle at a contact portion of the lock portion which is parallel to the axle axis, a reaction acts on the movement of the pressure ring in the axle direction at the time of contact. As a result, a limited slip differential gear having a lock portion with improved positioning accuracy has been completed. The present invention provides a limited slip differential gear in which, when an accelerator is turned on / off such as a curve or a turn during high-speed running, the pressure on the multi-plate friction clutch mechanism is reliably switched to a half-clutch state and the handle cannot be removed. Is what you do.

[0006]

That is, the present invention provides:
(1) A differential gear case that is rotated by the driving force from the engine, a pair of pressure rings provided in the case and movably in the axle direction, and an equilateral shape formed opposite to the pair of pressure rings. A V-shaped groove comprising a first cam surface and a second cam surface having an angle, a pinion shaft held between pressure rings corresponding to the V-shaped groove, and a pinion gear rotatably provided on the pinion shaft A pair of side gears that mesh so as to sandwich the pinion gear from both sides and transmit driving force to the axles on both sides; and a pair of side gears that are provided between the differential gear case and the side gears. A multi-plate clutch mechanism that limits the side gear differential by being crimped by the A ted slip differential gear, comprising: a lock portion projecting from a first cam surface and a second cam surface of the V-shaped groove, the lock portion comprising a first lock surface and a second lock surface; and the lock of the pinion shaft. A notch formed in a portion corresponding to the portion, the cutout including a first cutout surface and a second cutout surface, and between the first lock surface and the first notch surface when the lock portion and the cutout portion are engaged. The limited slip differential gear is formed so that a gap is formed in the gear.

The present invention provides (2) a differential gear case which is rotated by a driving force from an engine, a pair of pressure rings provided in the case and movably in the axle direction, and a pair of pressure rings. Are formed to face each other and are equilateral
A V-shaped groove including a cam surface and a second cam surface, a pinion shaft held between pressure rings corresponding to the V-shaped groove, a pinion gear rotatably provided on the pinion shaft, and the pinion gear A pair of side gears that mesh so as to sandwich them from both sides and transmit driving force to the axles on both sides, and are provided between the differential gear case and the side gears, and the pair of pressure rings are moved outward in the axial direction. A limited slip differential gear having a multi-plate clutch mechanism that limits the differential of the side gears by being crimped, wherein the first slip surface is formed on the first cam surface or the second cam surface of the V-shaped groove.
A lock portion including a lock surface and a second lock surface, a notch portion provided in a portion of the pinion shaft corresponding to the lock portion and including a first notch surface and a second notch surface, the lock portion and the notch The limited slip differential gear is characterized in that a gap is formed between the first lock surface and the first notch surface when the portion is engaged.

Further, according to the present invention, (3) the lock portion and the notch portion are formed in substantially the same triangular shape, and the lock portion has a second lock surface parallel to a surface orthogonal to the axle axis. A first lock surface that intersects with the second lock surface such that a vertex angle is formed at an acute angle, wherein the notch portion includes a second notch surface orthogonal to the axle axis, and the second notch surface. And a first notch surface which intersects so that an inner angle is formed at an acute angle with respect to the pressure ring. When the lock portion and the notch portion are engaged with each other, the second notch surface is slidably contacted with the second lock surface, Is
When the first cam surface or the second cam surface is in contact with the corresponding contact surface of the pinion shaft, the first cam surface or the second cam surface can be moved toward the multi-plate clutch mechanism only in the remaining range of the gap. ) Or (2).

[0009]

By adopting the limited slip differential gear as described above, when the accelerator is turned off during a curve or a turn during high-speed running, a driving force is input from the wheel side via a pinion shaft due to road surface resistance. With this input, the first cam contact surface of the pinion shaft comes into contact with the first cam surface of the V-shaped groove of the pressure ring, and the pressure ring is pushed and opened. Since the formed notch and the projection of the pressure ring are locked, further pushing and opening of the pressure ring is prevented.

Further, a driving force is input from the wheel side via a pinion shaft during forward running or reverse running. By this input, the first cam contact surface or the second cam contact surface of the pinion shaft contacts the first cam surface or the second cam surface of the V-shaped groove of the pressure ring, and the pressure ring is pushed open. When the pressure ring moves relative to the gap, a lock portion formed on the first cam surface or the second cam surface of the V-shaped groove and a cutout portion formed in a portion corresponding to the lock portion of the pinion shaft are formed. Because of the locked state, the pressure ring is prevented from being pushed further.

Further, when the lock portion and the notch portion formed in substantially the same triangle are locked, the lock portion and the notch portion formed at an acute angle are engaged with each other, so that the positioning accuracy at the time of locking is improved. Can be done. Further, since the amount of movement of the pressure ring is limited to be movable only in the range of the remaining gap, the degree of pressure contact of the pressure ring with the multi-plate clutch mechanism can be switched to the half-clutch state.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments and the drawings. 1 to 3 show an embodiment of a limited slip differential gear (hereinafter, referred to as “LSD”) according to the present invention.

First, the LSD 10 will be described. As shown in FIG. 3, a differential gear case 16 in which a ring gear 14 meshing with the drive pinion 12 is fixed.
Indicates that the driving force of the engine (not shown) is the drive pinion 1
2 to be rotated by being transmitted to the motor.
The axle 1 is accommodated in the differential gear case 16.
A pair of side gears 20, 20 connected to 8, 18 are provided. Between the side gears 20, 20, pinion gears 22,
22 mesh with each other.

A multi-plate friction clutch mechanism 64 is provided between the differential gear case 16 and the side gear 20.
The multi-plate friction clutch mechanism 64 is pressed by the axially outward movement of the pair of pressure rings 46 to limit the differential of the side gear 20.

The pinion gear 22 has a pinion shaft end 26 protruding from four sides of a cross-shaped pinion shaft 24.
, Each of which is pivotally supported. As shown in FIG. 1, a first cam contact surface 30 and a second cam contact surface 32 are formed on the left and right of the tip end portion 28 of the pinion shaft end 26, respectively, and have a substantially rhombic shape in plan view. . The first cam contact surface 30 has a first notch 40 formed therein, and the other second
A second notch 42 is formed in the cam contact surface 32.

The first notch 40 has a first notch surface 40.
A and a second notch surface 40B are formed, and the other second notch 4
2 has a first cutout surface 42A and a second cutout surface 42B. Further, the first notch 40 and the second notch 4
2 and second notch surface 40B and second notch surface 4
2B is formed in parallel with a plane orthogonal to the axes of the axles 18 and 18 (the angle θ1 with respect to the slope of the second cam contact surface 32 shown in FIG. 4). Also, the other first cutout surface 4
0A and the second notch surface 42A have their bottoms inclined toward the axles 18 and 18 with respect to the axes of the axles 18 and 18, respectively, and have an inner angle with one of the second notch surfaces 40B and the second notch surface 42B. Are formed at an acute angle θ2 (see FIG. 4A).

As shown in FIG. 1, a distal end portion 28 of the pinion shaft end 26 has a pressure ring 46, which is movable in the longitudinal direction of the axles 18, 18 (see FIG. 3).
46 to hold it. The pressure rings 46, 46 are set to rotate in the direction of arrow A when traveling forward, and in the direction of arrow B when traveling backward.

As shown in FIG. 2, V-shaped grooves 50 are formed opposite to each other at portions of the pressure rings 46, 46 corresponding to the distal end portions 28 of the pinion shaft ends 26. These V-shaped grooves 50 are formed by a first cam surface 52 and a second cam surface 54 which are equilateral and equiangular.
That is, the inclination angle α of the first cam surface 52 and the inclination angle α of the second cam surface 54 are the same, and the length of the first cam surface 52 and the length of the second cam surface 54 are the same.

Also, as shown in FIG.
Is opposed to the first cam contact surface 30 of the tip 28 of the pinion shaft end 26, and the second cam surface 54 is opposed to the second cam contact surface 32 of the tip 28 of the pinion shaft end 26. . As shown in FIG. 2, a first lock projection 56 is formed on the first cam surface 52, and a second lock projection 58 is formed on the second cam surface 54. The first lock projection 56 has a first lock surface 56A and a second lock surface 56A.
B are formed, and the second lock projection 58 is provided with the first
A lock surface 58A and a second lock surface 58B are formed respectively.

Further, one of the second lock surface 56B and the second lock surface 58B constituting the first lock protrusion 56 and the second lock protrusion 58 is parallel to a surface orthogonal to the axis of the axles 18, 18, respectively. Is formed. The other first lock surface 56A and first lock surface 58A are connected to the axles 18 and 18 respectively.
The front end is inclined toward the axles 18 and 18 with respect to a plane parallel to the axis of. The inner angle between the second lock surface 56B and the second lock surface 58B is an acute angle θ2.
[See FIG. 4A].

The second cutout surfaces 40B and 42B of the first and second cutouts 40 and 42 and the second lock surface 56 of the first and second lock projections 56 and 58 shown in FIGS.
B, 58B are slidably contacted on a plane orthogonal to the axles 18, 18. Accordingly, as shown in FIG. 1, the first lock projection 56 is engaged with the first notch 40 and the second lock projection 58 is engaged with the second notch 42. It is supposed to be.

As shown in FIG. 1, the pinion shaft end 2
6 The first notch surface 40A of the first notch portion 40 formed at the distal end portion 28 and the first lock surface 56A of the first lock protrusion 56
Between the first notch surface 42A of the second notch portion 42 and the second
A gap X is formed between the lock projection 58 and the first lock surface 58A.

As shown in FIG. 3, in the differential gear case 16, the pressure rings 46,
Between the gear 46 and the inner wall of the differential gear case 16, a friction disk 60 and a differential gear case 1 that operate integrally with the side gears 20, 20 are provided.
A multi-plate friction clutch mechanism 64 including a friction plate 62 that operates integrally with the clutch 6 is provided.

Next, the operation of the LSD will be described. First, when the engine is rotated, the drive pinion 12,
The differential gear case 16 rotates via the ring gear 14. Thus, the pair of pressure rings 46, 46 also rotate at the same speed as the differential gear case 16.

As shown in FIG. 1, the relationship between the pressure rings 46, 46 and the pinion shaft 24 is as follows.
Since the distal end portion 28 of the pinion shaft end 26 is engaged with the V-shaped groove 50 of the pressure ring 46, the rotation of the pressure ring 46 also rotates the pinion shaft 24. Therefore, when the resistances of the left and right wheels are equal, the resistances applied to the left and right side gears 20 are equal, so that the pinion gear 22 revolves around the axle 18 together with the differential gear case 16 without rotating, and the input from the drive pinion 12 is received. The ring gear 14, the pressure ring 46, the pinion shaft 24, the pinion gear 22, the side gear 20, and the axle 18 are transmitted evenly in this order.

Also, for example, when the accelerator is turned off during a curve or a turn while traveling forward at high speed, when a driving force is input from the wheel side through the tip portion 28 of the pinion shaft end 26 due to road surface resistance, the pinion shaft end 26 Tip 2 of
8 relatively moves in the direction of arrow B, and the pressure ring 46
The first cam contact surface 30 of the first cam surface 52 of the V-shaped groove 50 of FIG.
And the pressure ring 46 is pushed open in the direction of arrow C by the cam component P.

However, a predetermined gap X is formed between the first notch surface 40A and the first lock surface 56A, and the pressure ring 46 has the first cam surface 52 or the second cam surface 54 formed by the pinion shaft. In the state of contact with the first cam contact surface 30 or the second cam contact surface 32 corresponding to the corresponding contact surface 24, the relative movement in the P direction toward the multi-plate clutch mechanism 64 only within the range of the residual gap X1. I do. When the pressure ring 46 moves by a predetermined amount, the first notch 40
Notch surface 40A and first lock surface 5 of first lock protrusion 56
6A come into contact with each other, and the first cutout surface 40A and the first lock surface 56A are locked, so that the further movement of the pressure ring 46 beyond the arrow C is prevented.

Therefore, the pressure ring 46 includes the friction disk 60 and the friction plate 62.
Is weak, the multi-plate friction clutch mechanism 64 is in a so-called half-clutch state, and a strong driving force is applied to the axle 18.
, There is no danger that the handle will be removed.

Next, when the vehicle is traveling in reverse, the pressure ring 46 rotates in the direction of arrow B, so that the second cam contact surface 32 contacts the second cam surface 54 of the V-shaped groove 50 of the pressure ring 46. In contact therewith, the pressure ring 46 is pushed open in the direction of arrow C by the cam component P. Then, when the pressure ring 46 relatively moves by the remaining gap X1, the first notch surface 42A of the second notch portion 42 and the first lock surface 58A of the second lock protrusion portion 58 abut, and the first notch surface 4A
2A and the first lock surface 58A are locked. Therefore, the movement of the pressure ring 46 in the direction of the arrow C is prevented as in the case of the forward running.

More specifically, in the initial state of the pinion shaft end 26 and the pressure ring 46 shown in FIG. 4A, when the pressure ring 46 rotates in the direction of arrow B, as shown in FIG. So that the second cam surface 54 and the second cam contact surface 32 contact each other.
In this state, the interval of the gap X is reduced to X1, and the rotation is continued in the direction of arrow B, so that the pressure ring 46 moves in the direction C within the range of the remaining gap X1 due to the cam component P.

By the movement by the component force P, as shown in FIG. 4 (C), the first notch surface 42A inclined with respect to the axis of the axles 18, 18 (the inner angle θ2 of the bottom of the second notch portion 42) is formed. The first lock surfaces 58A come into contact with each other. Note that 0 ° <θ
2 <90 °, θ1 + θ2> 90 °. Due to this contact, a component force Q acts on the first notch surface 42A and the first lock surface 58A in a direction opposite to the cam component force P, and at the same time, the second cam surface 52 and the second cam contact surface 32 abut. In the contact state, the movement of the pressure ring 46 in the direction of the axle 18 can be reliably prevented.
Positioning accuracy can be improved.

Therefore, the pressure ring 46 includes a friction disk 60 and a friction plate 62.
, The multi-plate friction clutch mechanism 64 is in a so-called half-clutch state, and a strong driving force is not transmitted to the axle 18, so that there is no danger that the steering wheel will be removed. As described above, the aforementioned limited slip differential gear (LSD) has the first and second V-shaped grooves.
Two sets of first and second lock projections 56 and 58 are respectively provided on the cam surfaces 52 and 54 so as to project therefrom. The first and second lock projections 56 and 58 are formed in a substantially rhombic shape in plan view. The basic configuration is such that first and second cutouts 40 and 42 formed on the left and right of the distal end portion 28 of the pinion shaft end 26 are disposed correspondingly.

Although illustration is omitted for the LSD having such a configuration, as can be seen from FIGS.
2. The first lock projection 56 and the first notch 40 may be arranged so as to correspond to only the first cam contact surface 30, respectively, or the second cam surface 54 and the second cam contact surface 32 may be provided. Only the second lock projection 58 and the second notch 42 may be provided so as to correspond to each other.

That is, in the former case, the multi-plate clutch mechanism 64 can be brought into the half-clutch state only during forward traveling, and in the latter case, the multi-plate clutch mechanism 64 is brought into the half-clutch state only during reverse traveling. Can be done. The operation for locking the outward movement of the pressure ring 46 in the axial direction of the axle 18 is the same as that of the above-described embodiment in both the former case and the latter case, and thus the detailed description is omitted.

In the above embodiments, the V-shaped groove 50
The first and second lock projections 56 and 58 project from the first and second cam surfaces 52 and 54, respectively, and the first and second cam contact surfaces 30 and 32 of the pinion shaft end 26 are correspondingly provided. First,
Although the example in which the second notches 40 and 42 are recessed has been described, the concave-convex relationship between the V-shaped groove 50 and the lock projection formed on the pinion shaft end 26 and the notch is reversed. It is of course possible to do so.

The main components of the V-shaped groove 50 are a first and a second notch formed in the first and second cam surfaces 52 and 54, and a portion corresponding to the notch. First and second
A lock portion comprising a lock surface, wherein a gap is formed between the first lock surface and the first notch surface when the lock portion and the notch engage. Specifically, the enlarged view shown in FIG. 4A shows the relationship between the second lock surface 58 on the right side of the V-shaped groove 50 (see FIG. 1) and the second notch surface 42 in the embodiment. However, the configuration of the present embodiment is
This is a configuration in which the concavo-convex relationship in this figure is shifted to the upper left of FIG.

That is, the first cam contact surface 30 of the pinion shaft 26 shown in FIG. 4A is in contact with the first cam contact surface 52 of the V-shaped groove 50 and the second cam contact surface 52 of the V-shaped groove 50. The cam surface 54 corresponds to the first cutout surface 30 of the pinion shaft 26. Accordingly, the first and second cam contact surfaces 30, 32 of the pinion shaft 26 are provided with four lock projections, and
Correspondingly, four notches are recessed in the cam surface of the V-shaped groove 50.

When the lock portion and the cutout portion are engaged, a gap is formed between the first lock surface and the first cutout surface. As a modified example of this configuration,
Similarly to the above-described embodiment, a pair of left and right notches may be provided only on the first cam surface 52, and a pair of left and right protrusions may be provided only on the first cam contact surface 30, or only the second cam surface 54 may be provided with right and left. The pair of notches may be provided with a pair of left and right protrusions only on the second cam contact surface 32.

The present invention has been described above.
It is needless to say that the present invention is not limited to the embodiment, and other modifications can be made without departing from the essence or scope. For example, in the embodiment, the shapes of the first and second lock projections having substantially the same similarity to the triangles of the first and second cutouts at the end of the pinion shaft are not necessarily formed in a triangle. Is also good.

[0040]

The limited slip differential gear according to the present invention ensures that the pressure ring is pressed against the multi-plate friction clutch mechanism in a half-clutch state when the accelerator is off during a curve or a turn during high-speed running. This has an excellent effect that the torque from the differential gear case can be reduced to prevent the handle from being taken off.

Further, the pressure of the pressure ring against the multi-plate friction clutch mechanism can be surely brought into the half-clutch state only when the vehicle is traveling forward or backward, thereby reducing the torque from the differential gear case and reducing the handle. Has the excellent effect of preventing the removal of Further, when the lock portion and the notch formed in substantially the same triangular shape are locked, the lock portion and the notch formed at an acute angle with each other are securely engaged with each other so that the positioning accuracy of the pressure ring at the time of locking is improved. Therefore, the pressure contact with the multi-plate friction clutch mechanism can be reliably switched to the half-clutch state.

[Brief description of the drawings]

FIG. 1 is a partially enlarged plan view of a limited slip differential gear according to an embodiment of the present invention.

FIG. 2 is a partially enlarged plan view of a pressure ring applied to a limited slip differential gear according to one embodiment of the present invention.

FIG. 3 is a sectional view of a limited slip differential gear.

FIGS. 4A to 4C are explanatory views showing a state in which a second lock projection is engaged with the second notch and locked.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Limited slip differential gear 12 ... Drive pinion 14 ... Ring gear 16 ... Differential gear case 18 ... Axle 20 ... Side gear 22 ... Pinion gear 24 ... Pinion shaft 26 ... Pinion shaft end 28 ... Tip 30 ... First cam contact surface 32 ... second cam contact surface 40 ... first notch 40A ... first notch 40B ... second notch 42 ... second notch 42A ... first notch 42B ... second notch 46 ... pressure ring 50 ... V L-shaped groove 52 first cam surface 54 second cam surface 56 first lock protrusion 56A first lock surface 56B second lock surface 58 second lock protrusion 58A first lock surface 58B first 2 lock surface 64: multi-plate friction clutch mechanism X, X1: air gap

Claims (3)

[Claims] 1. A differential gear case which is rotated by a driving force from an engine, a pair of pressure rings provided in the case so as to be movable in an axle direction, and equilateral sides formed opposite the pair of pressure rings. A V-shaped groove including a first cam surface and a second cam surface having the same angle, a pinion shaft sandwiched between pressure rings corresponding to the V-shaped groove, and a rotatably provided pinion shaft. A pinion gear, a pair of side gears that mesh so as to sandwich the pinion gear from both sides and transmit driving force to the axles on both sides, and are provided between the differential gear case and the side gear; And a multi-plate clutch mechanism that limits the differential of the side gear by being crimped by A limited slip differential gear, comprising: a lock portion projecting from a first cam surface and a second cam surface of the V-shaped groove, the lock portion including a first lock surface and a second lock surface; A notch formed in the portion corresponding to the lock portion and having a first notch surface and a second notch surface, the first lock surface and the first notch when the lock portion and the notch portion are engaged A limited slip differential gear characterized in that a gap is formed between the gear and the surface. 2. A differential gear case which is rotated by a driving force from an engine, a pair of pressure rings provided in the case and movably in an axle direction, and equilateral sides formed opposite to the pair of pressure rings. A V-shaped groove including a first cam surface and a second cam surface having the same angle, a pinion shaft sandwiched between pressure rings corresponding to the V-shaped groove, and a rotatably provided pinion shaft. A pinion gear, a pair of side gears that mesh so as to sandwich the pinion gear from both sides and transmit driving force to the axles on both sides, and are provided between the differential gear case and the side gear; And a multi-plate clutch mechanism that limits the differential of the side gear by being crimped by A limited slip differential gear, the lock portion comprising a first lock surface and a second lock surface formed on a first cam surface or a second cam surface of the V-shaped groove; A notch formed in a portion corresponding to the lock portion and having a first notch surface and a second notch surface, wherein the first lock surface and the first notch are engaged when the lock portion and the notch portion are engaged with each other. A limited slip differential gear characterized in that a gap is formed between the gear and the surface. 3. The lock portion and the cutout portion are formed in substantially the same triangular shape. The lock portion has a second lock surface parallel to a surface orthogonal to the axle axis, and a top with respect to the second lock surface. A first lock surface intersecting so that an angle is formed at an acute angle, wherein the notch portion has a second notch surface orthogonal to the axle axis and an inner angle formed at an acute angle with respect to the second notch surface; The first notch surface intersects as described above, and when the lock portion and the notch portion are engaged, the second notch surface slides on the second lock surface,
The pressure ring is configured such that when the first cam surface or the second cam surface is in contact with the corresponding contact surface of the pinion shaft, the pressure ring can move toward the multi-plate clutch mechanism only within the remaining range of the gap. 2. The method according to claim 1, wherein
Or the limited slip differential gear according to 2.