JP2002323113A - Limited slip differential gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a limited slip differential gear, capable of reconciling straightly advancing traveling stability during straight advancing and suppression of an under steering tendency during turning, securing a traveling property during advancing and stack escapability at reversing. SOLUTION: Large cam component force to push and open a pressure ring is obtained by pressing a cam surface of a first cam groove, by pressing force by acceleration during advancing traveling and becomes a large differential limited amount during straight advancing by accelerator-on state to enhance straightly advancing stability. A second cam groove 32 obtaining small cam component force is set to be abutted on the side for inputting driving force from the wheel side by road surface resistance via a pinion shaft 16 at the time of accelerator-off during advancing traveling, and thereby the pinion shaft 16 obtains small cam component force by an operation of an accelerator-off to suppress the under steering tendency.

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, one wheel of a drive wheel slips on a road surface having a low coefficient of friction, such as a muddy ground, a sandy ground, a frozen road, or the like, and cannot be escaped. When you leave the road surface and touch the ground again, something like swinging ass happens. In order to compensate for such a drawback of a normal differential gear that causes a decrease in running performance, a limited slip differential gear (hereinafter, referred to as LSD) is used.

[0003] Such an LSD is formed at an end of a prism-shaped shaft adapted to fit an equilateral equiangular V-shaped groove mainly cut out in a pressure ring and a facing opening of the V-shaped groove. It is configured as a cam component mechanism using a pinion shaft.

[0004]

A conventional LSD of this kind
Has a structure in which a cam shape is formed at an end of a pinion shaft having a shape conforming to the V-shaped groove and an equilateral equiangular groove formed in the pressure ring. There are several problems arising from the inability to vary the cam component to the plate friction clutch mechanism. That is, if the cam angle is set such that a large cam component force can be obtained with respect to the drive input with emphasis on straight running stability, the differential limiting amount becomes too large when turning in the engine brake state due to the accelerator off. The point where the so-called understeer tendency tends to occur, that is, the vehicle tends to move straight ahead.

On the other hand, if the cam angle is set so that a small cam component force can be obtained with respect to the drive input so as to suppress the understeering tendency at the time of turning, the differential limiting amount will be reduced during straight running or when exiting a rough road. The point that it is small, and the straight running stability and the ability to escape on bad roads deteriorate.

When a compromise cam angle is set in consideration of the straight running stability and the suppression of understeer, mainly when the vehicle is traveling forward, when the vehicle escapes from a mud or the like by using forward and backward movement together, Insufficient differential limit and poor stack escape.

Further, when the cam angle is set so as to obtain a large cam component force with emphasis on the escape from the stack, a strong understeer occurs at the time of accelerating turning, resulting in inferior running performance in a passenger car.

Based on such technical background, the applicants have conducted intensive studies and as a result, it has been found that the relative operation of the LSD differs between when the accelerator is on and when the accelerator is off even when the vehicle is moving forward and when moving backward or when moving forward. The present invention has been completed by noting that the drive input directions are different.

According to the present invention, it is possible to achieve both the stability of straight running during straight running and the suppression of the tendency of understeering during turning, to secure the running performance during forward running and to improve the stack escape property due to reverse running. A limited slip differential gear is provided.

[0010]

That is, the present invention provides:
(1) A differential gear case which is rotated by a driving force from an engine, a pair of pressure rings provided in the case and provided to be movable in the axle direction, and formed on surfaces of the pair of pressure rings opposed to each other. First and second cam grooves, and the first and second cam grooves
A pinion shaft sandwiched between the cam grooves and orthogonal to the axle, at least a pair of pinion gears rotatably supported by the pinion shaft supported by the case, and meshed with the pinion gear housed in the case so as to sandwich the pinion gear from both sides; , A pair of side gears for transmitting driving force to both axles, and a multi-plate friction clutch mechanism for limiting the operation of the case and each side gear, a limited slip differential gear, wherein the first cam groove is
The second cam groove includes a bottom surface parallel to the rotation direction of the pressure ring, a first cam surface perpendicular to the bottom surface, and a second cam surface inclined with respect to the bottom surface. Is composed of a bottom surface parallel to the rotation direction of the pressure ring and a pair of first and second cam surfaces perpendicular to the bottom surface, and has a U-shaped groove corresponding to the first cam groove of the pinion shaft. On one side,
The other is formed of a plane parallel to the bottom surface of the first cam groove, and first and second inclined contact surfaces formed on both sides of the plane, and corresponds to the second cam groove of the pinion shaft. On the side surface, the limited slip differential gear includes a plane parallel to the bottom surface of the second cam groove and first and second arc contact surfaces formed on both sides of the plane.

(2) A differential gear case which is rotated by the driving force from the engine, a pair of pressure rings provided in the case and provided to be movable in the axle direction, and the pair of pressure rings face each other. First and second cam grooves formed on the surface;
A pinion shaft interposed between the first and second cam grooves and orthogonal to the axle; at least a pair of pinion gears rotatably supported by the pinion shaft supported by the case; and the pinion gear housed in the case. A limited slip differential gear comprising: a pair of side gears that mesh with each other so as to be sandwiched from both sides and transmit a driving force to the axles on both sides; and a multi-plate friction clutch mechanism that limits the operation of the case and each side gear. The first cam groove is recessed in the opposing surface of the one pressure ring, and the second cam surface is inclined with respect to the first cam surface and the bottom surface perpendicular to the bottom surface parallel to the rotation direction of the pressure ring and the bottom surface.
The second cam groove includes a bottom surface parallel to the rotation direction of the pressure ring, and a pair of first and second cam surfaces perpendicular to the bottom surface. The pinion shaft is formed of a U-shaped groove having a gentle upward slope toward the two cam surfaces, and one side surface of the pinion shaft corresponding to the first cam groove is parallel to the bottom surface of the first cam groove. And the first and second inclined contact surfaces formed on both sides of the flat surface, and the other side surface corresponding to the second cam groove of the pinion shaft has a second cam groove. The present invention is a limited slip differential gear comprising a gentle inclined surface parallel to the gentle upward inclined bottom surface and first and second arc contact surfaces formed on both sides of the inclined surface.

(3) A differential gear case which is rotated by a driving force from an engine, a pair of pressure rings provided in the case and provided to be movable in the axle direction, and one of the pair of pressure rings is provided. A first cam groove formed on a flat end surface facing the flat end surface; a pinion shaft interposed between the one flat end surface and the first cam groove and orthogonal to an axle; and supported by the case. At least a pair of pinion gears rotatably supported by a pinion shaft, a pair of side gears housed in the case and meshing so as to sandwich the pinion gear from both sides and transmitting driving force to axles on both sides; and the case and each side gear Limited slip differential gear provided with a multi-plate friction clutch mechanism for restricting the operation of the clutch There, the first cam groove, one of the pressure is recessed in the facing surface of the ring, the first perpendicular to the direction of rotation and parallel to the bottom surface and the bottom surface of the pressure ring
A cam surface and a second cam surface inclined with respect to the bottom surface. Both ends of the pinion shaft are provided on one side surface corresponding to the first cam groove, in parallel with the bottom surface of the first cam groove. A plane and first and second planes formed on both sides of the plane.
A limited slip differential gear characterized in that an inclined contact surface is formed.

[0013]

By employing the limited slip differential gear as described above, the vehicle is accelerated during forward running and the driving force is input from the engine via the pressure ring. With this input, when the pressure ring rotates in a predetermined direction, a large cam component force is obtained which presses the cam surface of the first cam groove formed on one of the pressure rings with a pressing force to push the pressure ring open. . Therefore, when the vehicle is running straight due to the accelerator-on, the amount of differential limitation is large, so that the straight running stability is improved. Further, when the accelerator is turned off during forward running, the second cam groove is set to abut on the side where the driving force is input from the wheel side via the pinion shaft due to road surface resistance. Therefore, when the pinion shaft is rotated in a predetermined direction by the accelerator-off operation, a small cam component force is obtained. Therefore, during a turn in which the accelerator-off operation is performed, the operation limit amount is small, and the tendency to understeer is suppressed.

Further, by adopting the limited slip differential gear as described above, a driving force is input to the pressure ring from a predetermined direction during forward movement, and a relatively small cam component is applied. And running performance is ensured. When the vehicle travels backward, a driving force is input to the pressure ring from a predetermined direction, resulting in a large component force. Therefore, the use of the backward movement at the time of exiting the stack improves the escape property of the stack.

Further, by employing the limited slip differential gear as described above, the vehicle is accelerated during forward running, and the driving force is input from the engine via the pressure ring. By this input, when the pressure ring rotates in a predetermined direction, a relatively large cam component force for pushing the cam surface of the first cam groove formed in the pressure ring to push open the pressure ring is obtained. Therefore, when the vehicle is running straight due to the accelerator-on, the amount of differential limitation is large, so that the straight running stability is improved.
Further, when the accelerator is turned off during forward running, the driving force is input from the wheel side via the pinion shaft due to road surface resistance, so that the cam component becomes a relatively small cam component,
When the pinion shaft is rotated in a predetermined direction by the accelerator-off operation, the turning amount when the accelerator-off operation is performed becomes a very small operation restriction amount, and the understeer tendency is suppressed.

[0016]

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

First, the LSD 1 will be described. As shown in FIG. 1, a differential gear case 2 in which a ring gear LG meshing with a drive pinion DP is fixed.
Is rotated by transmitting the driving force of an engine (not shown) to the drive pinion.

A pair of side gears 10 connected to axles 8a and 8b are provided in the differential gear case 2.
a and 10b are provided. These side gears 10
a, 10b, these side gears 10a, 10b
b, the plurality of pinion gears 12 mesh with each other.

Between the differential gear case 2 and the side gears 10a and 10b, a known multi-plate friction clutch mechanism 2 in which friction plates composed of friction disks and friction plates are alternately superposed and combined.
0 and 20 are interposed. These multi-plate friction clutch mechanisms 20, 20 include a pair of pressure rings 18a, 1
8b is crimped by moving outward from the center side in the axial direction to limit the differential between the side gears 10a and 10b. The pinion gears 12 are rotatably supported by pinion shaft ends 16a and 16b projecting from four sides of a cross-shaped pinion shaft 16, respectively.

These pinion shaft ends 16a, 16b
Are held by pressure rings 18a, 18b movable in the longitudinal direction of the axles 8a, 8b. The pressure rings 18a, 18b move in the direction of arrow B when the vehicle travels forward, and travel backward. When it does, it is set to rotate in the direction of arrow A (see FIG. 2).

Next, as shown in FIG. 2, first inclined contact surfaces 2 are provided on the left and right side surfaces of the pinion shaft ends 16a, 16b.
An equilateral equiangular (in the figure, an isosceles triangular shape) triangular cam 24 composed of 4a and a second inclined contact surface 24b, and a first arc contact surface 26a and a second arc contact surface constituted by arcs of the same radius. An arc cam 26 composed of 26b is formed. Flat surfaces 25 and 27 parallel to each other are formed on the top or arc cam 26 of the triangular cam 24.

On the other hand, the pinion shaft ends 16a, 16b
A first cam groove 28 formed in a boat shape corresponding to the triangular cam 24 and a second cam groove 30 formed in a U-shape corresponding to the circular cam 26 are formed on the opposing surfaces of the pressure rings 18a and 18b sandwiching the. Are arranged respectively.

The first cam groove 28 is provided at the end 1 of the pinion shaft.
A cam surface 28a formed on the same inclined surface as the inclined surface of the second inclined contact surface 24b of 6a, 16b;
And a cam surface 28b perpendicular to a bottom surface 28c parallel to the rotation direction of 8a, 18b. Further, the second cam groove 30 is formed on the bottom surface 3 parallel to the bottom surface 28 c of the first cam groove 28.
0c, vertical cam surfaces 30a, 30b formed on both sides.
Are formed.

The triangular cams 24 and the circular cams 26 at the pinion shaft ends 16a and 16b are loosely fitted in the corresponding first cam grooves 28 and the second cam grooves 30, respectively. 25, 27 are bottom surfaces 28c and 3
0c is slidably contacted (in the drawing, a gap is provided for convenience to explain the state of contact between the surfaces).

Next, the operation of the first embodiment of the LSD will be described. As shown in FIG. 1, when the engine is driven to rotate, the ring gear L is driven by the drive pinion DP.
When the differential gear case 2 is rotated via the G, the pair of pressure rings 18a and 18b fixed in the rotation direction are also changed.
It rotates at the same speed as.

Then, the two pressure rings 18a, 1
Similarly, the pinion shaft 16 sandwiched between the first cam groove 28 and the second cam groove 30 formed on the opposing surface of the axle 8a rotates together with the differential gear case 2 while rotating. , 8
revolves around b). As described above, the driving force (torque) is transmitted from the drive pinion DP via the ring gear LG to the differential gear case 2, the pressure rings 18a and 18b, the pinion shaft 16, the pinion gear 12, the side gears 10a and 10b, and the axles 8a and 8b.
Are transmitted in this order.

That is, when the vehicle is traveling straight, the resistances of the left and right wheels are equal, so that the resistances applied to the left and right side gears 10a and 10b are equal, and there is no relative speed between the differential gear case 2 and the side gears 10a and 10b.

When there is a rotation difference between the left and right wheels, the torque is equally divided between the left and right wheels as in the case of going straight, but the torque transmitted to the high-speed wheels corresponds to the road surface resistance of the wheels. Since only a minute 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 this clutch resistance acts on the side gear 10a or 1
0b via the differential gear case 2 and the torque transmitted to the low-speed wheels is added by the clutch resistance. As described above, when there is a difference in rotation between the left and right wheels, the torque transmission indicates that a large amount of torque is distributed to the slower rotating wheel.

Next, the action of the component force in the cam mechanism will be described. When the driving force is applied to accelerate the vehicle forward, as shown in FIG.
8b rotates in the direction of the arrow. Therefore, the pressure ring 1 is attached to the second inclined contact surface 24b of the triangular cam 24 formed on one side surface of the pinion shaft ends 16a, 16b.
A cam surface 28a formed as an inclined surface of the first cam groove 28 formed on the opposing surface 8b abuts. At the same time,
A predetermined portion of the first arc contact surface 26a of the arc cam 26 formed on the other side surface of the pinion shaft ends 16a, 16b is formed on the opposite surface of the pressure ring 18a.
It comes into contact with the corner P1 of the cam groove 30. It is apparent that the magnitude of the component force F2 varies depending on the contact portion of the first arc contact surface 26a of the arc cam 26 that contacts the corner P1 of the second cam groove 30.

Due to the cam's component action due to this contact, the pressure rings 18a, 18b cause the component forces F1, F, respectively.
Receiving 2, the pusher is opened in the direction of arrow C, and the multiple disc friction clutch mechanisms 20, 22 are pushed back.

That is, on the side where the driving force is input from the engine via the pressure rings 18a and 18b during acceleration while traveling forward, the second inclined contact surfaces of the pinion shaft ends 16a and 16b as shown in FIG. 24b is set as an inclined surface of the cam angle at which a large cam component force F1 is obtained. Therefore, the pressure rings 18a, 1
8b rotates in the direction B, the pressure ring 18
A cam component force F1 is obtained which presses the cam surface 28a of the first cam groove 28 formed at b with the pressing force R to open the pressure rings 18a and 18b. by this,
When the vehicle is running straight with the accelerator on, a large differential limiting amount is provided, so that the straight running stability is improved.

As shown in FIG. 2, an arc cam 26 formed on one side of the pinion shaft ends 16a, 16b and a second cam groove 30 formed on the pressure ring 18a.
When the accelerator is turned off during forward running, the driving force is input from the wheel side via the pinion shaft 16 due to the road surface resistance, and at a predetermined position of the first arc contact surface 26a, The corner P1 of the second cam groove 30 is set to abut. Therefore, when the pinion shaft 16 rotates in the direction of the arrow B due to the accelerator-off operation, a small cam component force F2 is obtained.

Therefore, when the vehicle is turned to perform the accelerator-off operation, the operation limit amount is small, and the tendency of understeer is suppressed.

As described above, in the first embodiment, it is possible to achieve both running stability during straight running and suppression of understeer tendency during turning without preparing a combination of a plurality of cams or changing the cams. Becomes possible.

Next, as shown in FIG. 3, during reverse traveling, the pressure rings 18a, 18b rotate in the direction of arrow A. Therefore, the pinion shaft ends 16a, 16
b of the first inclined contact surface 24a is
And the corner P2 of the second cam groove 30 abuts on a predetermined position of the second arc contact surface 26b, thereby receiving the component forces F3 and F4, respectively, and pushing and opening in the direction of arrow C. As a result, the multiple disc friction clutch mechanisms 20, 22 are pushed back.

That is, on the side where the driving force is input from the engine via the pressure rings 18a and 18b while being accelerated during the reverse running, the second inclined contact surfaces 24a of the pinion shaft ends 16a and 16b as shown in FIG. However, it is set as an inclined surface of a cam angle at which a large cam component force F3 is obtained. Therefore, the pressure rings 18a, 18
When b rotates in the direction A, the pressure ring 18
a, the cam surface 28b of the first cam groove 28 formed in the 18b
Of the pressure ring 1 by pressing the corner P3 of the
A cam component force F3 that tries to push open 8b is obtained. As a result, when the vehicle is traveling backward by the accelerator-on, the amount of differential limitation is large, so that the straight traveling stability is improved.

As shown in FIG. 3, an arc cam 26 formed on one side of the pinion shaft ends 16a, 16b and a second cam groove 30 formed on the pressure ring 18a.
When the accelerator is turned off during reverse travel, the driving force is input from the wheel side via the pinion shaft 16 due to the road surface resistance, and at a predetermined position of the second arc contact surface 26b, The corner P2 of the second cam groove 30 is set to abut. Therefore, when the pinion shaft 16 is rotated in the direction of arrow A by the accelerator-off operation, a small cam component force F4 is obtained.

Accordingly, when the vehicle is turned to perform the accelerator-off operation, the operation limit amount is small, and the understeer tendency is suppressed. In this way, it is possible to achieve both running stability and suppression of the tendency to understeer at the time of turning as well as at the time of going straight, as in the case of going straight.

Next, a second embodiment shown in FIGS. 4 and 5 will be described.

In this embodiment, the configuration of the LSD is the same as that of the first embodiment, but the configuration of the combination cam is different. The same components as those of the first embodiment are denoted by the same reference numerals, and detailed description is omitted.

That is, a triangular cam 24 formed on one side of the pinion shaft ends 16a, 16b shown in FIG. 1, and a first cam groove formed in a boat shape on the opposing surface of the pressure ring 18b corresponding to the triangular cam 24. 28 has the same configuration as that of the first embodiment, but has a pinion shaft end 16a,
The second embodiment is different from the first embodiment in an arc cam 26 formed on the opposite side of 16b and a second cam groove 32 formed in a boat shape on the facing surface of the pressure ring 18a corresponding to the arc cam 26. Things.

The second cam groove 32 in the present embodiment is formed on a part of the bottom surface 30c as a cam surface 30d which is gently inclined upward from an intermediate portion, and the pinion shaft end 16a,
The flat surface formed on the top of the arc cam 26 formed on the opposite side of the cam groove 16b is formed as a contact surface 36 having the same inclination as the cam surface 30d formed on the bottom surface 30c of the second cam groove 32. Therefore, the operation and effect of the component force in the cam mechanism shown in FIG. 4 are the same as those in the first embodiment, and a duplicate description will be omitted.

Next, the action of the component force in the cam mechanism shown in FIG. 5 will be described. The state shown in FIG. 5 shows a state in which the vehicle travels backward, and the pressure rings 18a and 18b rotate in the direction of arrow A during backward travel. Therefore, the first inclined contact surfaces 24 of the pinion shaft ends 16a, 16b
a comes into contact with the corner P3 of the first cam groove 28 of the pressure ring 18b, and the pinion shaft end 16
The cam surfaces 30d of a and 16b come into contact with the gently inclined cam surface 30d on the bottom surface of the second cam groove 32.

As a result, the components F3 and F5 generated are pushed and opened in the direction of arrow C, and the multi-plate friction clutch mechanism 2 is opened.
0, 22 will be pushed back.

That is, in this embodiment, the cam mechanism is
On the forward side, a relatively small component force F1 that does not require a large operation limiting function is set so that a relatively small component force F1 is obtained, and on the reverse side, a contact surface having the same inclination as the gentle upwardly inclined cam surface 30d that provides a large cam component force F5. 36 is set as a cam mechanism in combination.

Therefore, when moving forward, the pressure ring 1
Driving force is input to 8a and 18b from the direction of arrow B,
Since the cam component force F1 is relatively small, the traveling performance is ensured without strong understeering during acceleration turning.

In reverse, the pressure ring 1
A driving force is input to the direction 8a and 18b from the direction of arrow A, and a large component force F5 is obtained.

As described above, in the second embodiment, it is possible to maintain the traveling performance at the time of forward traveling and to improve the stack escape property by the reverse traveling without preparing a combination of a plurality of cam mechanisms or changing the combination. Can be achieved.

Next, a third embodiment shown in FIGS. 6 and 7 will be described.

The configuration of the LSD in this embodiment is the same as that of the first and second embodiments, but the configuration of the combination cam is different. The same components as those of the above embodiments are denoted by the same reference numerals, and detailed description is omitted.

That is, a triangular cam 24 formed on one side of the pinion shaft ends 16a and 16b shown in FIG. 1, and a first cam groove formed in a boat-shape on an opposing surface of the pressure ring 18b corresponding to the triangular cam 24. 28 has the same configuration as that of the first embodiment, but has a pinion shaft end 16a,
The first and second embodiments are different from the first and second embodiments in that an arc cam 26 formed on the opposite side to the arc cam 16b and an opposing surface of the pressure ring 18a corresponding to the arc cam 26 are formed as parallel flat end faces 38. Are different.

One of the pressure rings in this embodiment is formed in the shape of a flat end surface 38.
A flat surface 27 at the top of an arc cam 26 formed on the opposite side of the pinion shaft ends 16a and 16b facing the slidable contact.

Next, the action of the component force in the cam mechanism will be described. When the driving force is applied to accelerate the vehicle forward, as shown in FIG.
b rotates in the direction of the arrow. Therefore, the triangular cam 2 formed on one side surface of the pinion shaft ends 16a, 16b
4, the pressure ring 18 is attached to the second inclined contact surface 24b.
The cam surface 28a formed as an inclined surface of the first cam groove 28 formed on the opposing surface of b contacts. At this time, the flat surfaces 27 of the pinion shaft ends 16a and 16b are pressed by the flat end surface of the pressure ring 18a.

Due to the contact of the cam surfaces, the pressure rings 18a and 18b receive the component force F1 of only one side and are pushed and opened in the direction of arrow C, and the multi-plate friction clutch mechanisms 20 and 22 are opened.
Will be pushed back.

That is, on the side where the driving force is input from the engine via the pressure rings 18a and 18b while being accelerated during forward running, the second inclined contact surfaces 24b of the pinion shaft ends 16a and 16b as shown in FIG. Is set as an inclined surface of a cam angle at which a large cam component force F1 is obtained. Therefore, the pressure rings 18a, 18
When b rotates in the B direction, the pressure ring 18b
The pressing force R is applied to the cam surface 28a of the first cam groove 28 formed in
, And a cam component force F1 for pushing and opening the pressure rings 18a and 18b is obtained. As a result, when the vehicle is running straight with the accelerator on, the amount of differential limitation is large, so that the straight running stability is improved.

As shown in FIG. 7, when the vehicle travels in the reverse direction, the pressure rings 18a, 18b rotate in the direction of arrow A, so that the first inclined contact surfaces 24a of the pinion shaft ends 16a, 16b are angled with the pressure ring 18b. The contact with the portion P3 causes the component force F3 to be pushed and opened in the direction of arrow C to push back the multiple disc friction clutch mechanisms 20, 22.

That is, on the side where the driving force is input from the engine via the pressure rings 18a and 18b while being accelerated during reverse running, the second inclined contact surfaces 24a of the pinion shaft ends 16a and 16b as shown in FIG. However, it is set as an inclined surface of a cam angle at which a large cam component force F3 is obtained. Therefore, the pressure rings 18a, 18
When b rotates in the direction A, the pressure ring 18
a, the cam surface 28b of the first cam groove 28 formed in the 18b
Of the pressure ring 1 by pressing the corner P3 of the
A cam component force F3 that tries to push open 8b is obtained. As a result, when the vehicle is traveling backward by the accelerator-on, the amount of differential limitation is large, so that the straight traveling stability is improved.

Although the present invention has been described above, the present invention is not limited to the embodiment, and it goes without saying that other modifications can be made without departing from the essence of the present invention.

[0059]

According to the present invention having the above-described structure, (a) According to the first aspect of the present invention, a large differential limiting amount is obtained when the vehicle is traveling straight ahead with the accelerator on when traveling forward. The straight running stability is improved, and it is possible to achieve both running stability during straight running and suppression of understeer tendency during turning without preparing a combination of a plurality of cams or changing the cams.

(B) According to the second aspect of the invention, a relatively small cam component force is obtained when the vehicle is moving forward, so that traveling performance is secured without strong understeering during acceleration turning, and a large component force is obtained when the vehicle is moving backward. As a result, the use of the reverse drive at the time of stack escape improves the stack escape property, ensuring the traveling performance at the time of forward movement and the stack escape property by the reverse movement without preparing a combination of multiple cam mechanisms or changing the combination. Can be improved.

(C) According to the third aspect of the invention, substantially the same effects as those of the first aspect can be obtained, but in addition to this, since the processing of one pressure ring is simplified, the processing cost can be reduced. Becomes

[Brief description of the drawings]

FIG. 1 is a sectional view of a limited slip differential gear showing one embodiment of the present invention.

FIG. 2 is a partially enlarged conceptual view showing a cam mechanism of a limited slip differential gear as a first embodiment of the present invention.

FIG. 3 is a partially enlarged conceptual view showing a cam mechanism of the limited slip differential gear according to the first embodiment of the present invention.

FIG. 4 is a partially enlarged conceptual view showing a cam mechanism of a limited slip differential gear according to a second embodiment of the present invention.

FIG. 5 is a partially enlarged conceptual view showing a cam mechanism of a limited slip differential gear 5 as a second embodiment of the present invention.

FIG. 6 is a partially enlarged conceptual view showing a cam mechanism of a limited slip differential gear according to a third embodiment of the present invention.

FIG. 7 is a partially enlarged conceptual view showing a cam mechanism of a limited slip differential gear according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Differential gear (LSD) 2 ... Differential gear case 8a, 8b ... Axle 10a, 10b ... Side gear 12 ... Pinion gear 16 ... Pinion shaft 16a, 16b ... Pinion shaft end 18a, 18b ... Pressure ring 20, 22 ... Multi-plate friction clutch mechanism 24a, 24b ... inclined contact surface 24 ... triangular cam 25, 27 ... flat surface 26 ... arc cam 26a, 26b ... arc contact surface 28 ... first cam groove 28a, 28b ... cam surface 28c ... bottom surface 30 ... second cam Groove 30a Cam surface 30b Cam surface 30c Bottom surface 30d Cam surface 32 Second cam groove 36 Contact surface 38 Flat end surface DP Drive pinion F1, F2 Cam component F3, F4 Cam Component force F5: Cam component force LG: Ring gear P1, P2, P3: Corner R: Pressing force

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J027 FA07 FA34 FA43 FB02 HA01 HA03 HB07 HB12 HC22 HC23 HC29 HD02 HE01 HF04 HG03 HH01 HH03 HH04 HH05 HK09 HK25 3J056 AA60 BA04 BB21 CC34 GA03 GA12

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 formed on opposite surfaces of the pair of pressure rings. First and second cam grooves, a pinion shaft sandwiched between the first and second cam grooves, and orthogonal to the axle; and at least a pair of pinion gears rotatably supported by the pinion shaft supported by the case. A pair of side gears that are housed in the case, mesh so as to sandwich the pinion gear from both sides, and transmit driving force to the axles on both sides, and a multi-plate friction clutch mechanism that limits the operation of the case and each side gear. A limited slip differential gear, wherein the first cam groove has one pressure The second cam groove, comprising a bottom surface that is recessed in the facing surface of the pressure ring, is parallel to the rotation direction of the pressure ring, has a first cam surface perpendicular to the bottom surface, and a second cam surface that is inclined with respect to the bottom surface. Is composed of a bottom surface parallel to the rotation direction of the pressure ring, and a U-shaped groove formed by a pair of first and second cam surfaces perpendicular to the bottom surface. A flat surface parallel to the bottom surface of the first cam groove and first and second inclined contact surfaces formed on both sides of the flat surface are formed on one side surface corresponding to the cam groove, and the pinion shaft is formed. On the other side corresponding to the second cam groove, a plane parallel to the bottom surface of the second cam groove, and first and second arc contact surfaces formed on both sides of the plane are formed. Limited slip differential gear. 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 provided to be movable in an axle direction, and formed on surfaces of the pair of pressure rings opposed to each other. First and second cam grooves, a pinion shaft interposed between the first and second cam grooves and orthogonal to the axle, and at least one pair of pinion gears rotatably supported by the pinion shaft supported by the case. A pair of side gears that are housed in the case, mesh so as to sandwich the pinion gear from both sides, and transmit driving force to the axles on both sides, and a multi-plate friction clutch mechanism that limits the operation of the case and each side gear. A limited slip differential gear, wherein the first cam groove has one pressure A bottom surface parallel to the rotation direction of the pressure ring, a first cam surface perpendicular to the bottom surface, and a second cam surface inclined with respect to the bottom surface. A bottom surface parallel to the rotation direction of the pressure ring, and a pair of first and second cam surfaces perpendicular to the bottom surface, and a gentle upward slope is formed from substantially the middle of the bottom surface toward the second cam surface. On both sides of the pinion shaft, on one side corresponding to the first cam groove, on a plane parallel to the bottom surface of the first cam groove, and on both sides of the plane. The first and second inclined contact surfaces formed are formed, and the other side surface corresponding to the second cam groove of the pinion shaft has a gentle inclination parallel to the bottom surface of the second cam groove having a gentle upward inclination. Surface and first and second surfaces formed on both sides of the inclined surface. A limited slip differential gear having a two-arc contact surface. 3. A differential gear case that 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 one of the pair of pressure rings is a flat end surface. A first cam groove formed on a surface facing the flat end surface;
A pinion shaft sandwiched between the one flat end surface and the first cam groove and orthogonal to the axle; at least a pair of pinion gears rotatably supported by a pinion shaft supported by the case; A limited slip differential gear comprising: a pair of side gears that mesh so as to pinch a pinion gear from both sides and transmit driving force to axles on both sides; and a multi-plate friction clutch mechanism that limits the operation of the case and each side gear. The first cam groove is recessed in an opposing surface of one of the pressure rings, and has a bottom surface parallel to a rotation direction of the pressure ring, a first cam surface perpendicular to the bottom surface, and a second cam inclined with respect to the bottom surface. And at both ends of the pinion shaft, one side corresponding to the first cam groove, Limited slip differential gear, characterized in that the bottom surface parallel to the flat end surface of the cam groove, the first and second inclined abutment surface formed on both sides of the flat end surfaces are formed.