JP3485101B2 - Differential device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential device having a differential limiting function.

[0002]

2. Description of the Related Art As a differential of an automobile, a differential in which, when only one wheel is about to idle, a sufficient rotational force is transmitted to the other wheel via clutch means. A differential device (limited slip differential) with a limiting function, for example, one side of the wheel is ice or snow,
It is possible to prevent the wheel from slipping on a mud or the like and prevent the rotational force from being sufficiently transmitted to the other wheel,
It is widely used to prevent the body swinging phenomenon when turning or suddenly starting.

For example, Japanese Patent Publication No. 55-27980.
Japanese Unexamined Patent Publication No. 58-221046 discloses a differential device 100 as shown in FIG. This differential device 10
Reference numeral 0 denotes a pair of pressure rings 103 provided in the differential case 101 so as to be movable in the direction of the axle 102 and non-rotatable relative to each other, and orthogonal to the axle 102 with the shaft ends held between the pressure rings 103. The pinion shaft 104, the pinion gear 105 rotatably provided on the pinion shaft 104, and the pair of side gears 106 respectively provided on the shaft ends of the left and right axles 102 so as not to rotate relative to each other.
And a pair of side gears 10 that sandwich the pinion gear 105 and mesh with the pinion gear 105 on both sides thereof.
6, a pair of operating means 108 for operating the pressure ring 103 in a direction in which the clearance 107 between the pressure rings 103 increases in accordance with an increase in the relative rotational torque between the pinion shaft 104 and the differential case 101 during differential operation. The clutch means 109 are arranged on both sides of the pressure ring 103 in the axle direction.
The clutch means 109 is provided to limit the differential between the left and right axles 102 in accordance with the increase of the.

As the operating means 108, various shapes have been proposed. For example, the pinion shaft 10
A quadrilateral cam portion 110 having one diagonal line set in the axial direction is formed at the shaft end of 4, and a substantially V-shaped cam groove 111 that engages with the cam portion 110 is formed in the pressure ring 103. ing. In addition, this differential device 100
Then, the relative rotation torque is generated between the pinion shaft 104 and the differential case 101, and the clearance 107 between the pressure rings 103 is widened by the operation means 108, so that the clutch means 109 is operated and the differential between the left and right wheels is limited. However, in normal times, elastic members 112 such as disc springs are arranged outside the clutch means 109 in the axle direction so that the clearances 107 of the pressure rings 103 return to the set intervals. The pressure rings 103 are configured to be urged toward each other via the clutch plate 113 of the.

By the way, in such a differential device 100, in order to ensure that the differential of the left and right wheels is limited by the clutch means 109 in the differential limited state, the area of the friction pressure contact portion of the clutch plate 113 is increased. Must be sufficiently secured. However, the size of the differential case 101 is difficult to set larger than the current one due to the restriction of the positional relationship between the differential device 100 and various devices on the automobile side. It has been extremely difficult to obtain a sufficient differential limiting action compared to the current situation by increasing the number or setting the size large.

Particularly, in a horizontally installed engine vehicle, the restrictions on the layout of the engine and its peripheral parts are more severe than in a vertically installed engine vehicle, and the shape and capacity of the differential case are greatly restricted. For example, as shown in FIG. Differential device 12 shown
0, it is necessary to reduce the diameter of the right portion of the differential case 121, and it is difficult to set the area of the friction pressure contact portion of the clutch means 122 to be sufficiently large, and the elastic member 123 is attached to increase the friction pressure contact force. If the power is increased, as described above, the differential state cannot be obtained at the time of low-speed turning or the like, so that it is impossible to obtain a sufficient differential limiting action.

[0007]

As a result of extensive studies by the applicant of the present invention in order to sufficiently secure the frictional pressure contact force of the clutch plate, in the conventional differential device, the clutch means arranged on both sides in the axial direction of both pressure rings. Was set as one of the design conditions, but it was found that the same differential limiting action can be obtained even if one of the clutch means is omitted, and the differential device 120A shown in FIG. As described above, it is proposed to dispose the clutch means 122A only between the left side portion and the left side axle 102 of the differential case 121A having a sufficient space. However, even in this differential device 120A, depending on the shape of the differential case 121A, if the differential case 121B having a large diameter on the right side is adopted, as shown by phantom lines in FIG. When a large amount of waste meat was formed, a problem occurred. In addition to the above, the differential devices 100, 1
In 120 and 120A, the side wall portion 1 extending to the vicinity of the sleeve portion of the side gear 106 is attached to the pressure ring 103 in order to receive substantially the entire side surface of the clutch plate 113.
No. 03a is formed, the number of clutch plates 113 that can be accommodated is reduced by the thickness t of the side wall portion 103a, and it has been found that there is still room for improving the friction pressure contact force of the clutch plates 113.

Further, in the differential device as described above,
Basically, it becomes a differential state so that a small turn can be used when turning slowly for garage parking or parallel parking, etc., and stable expected performance when turning one wheel idle or sudden start, turning at high speed, high load It is preferable that the differential limited state is obtained such that

However, in the conventional differential device, for example, as seen in the differential device 100, the left and right pressure rings 103 are connected to the elastic member 11 via the clutch plate 113.
When the urging force is set to be weak because of urging the two toward each other, the clutch means 109 can be easily operated by the operating means 108, and the differential limiting state can be achieved even during low-speed turning. However, if the differential state is not stable and the biasing force is increased, the operating means 108 is brought into a differential state, but the biasing force of the elastic member 112 causes the clutch plate 113 to be constantly frictionally pressed to cause a substantial difference. Since the differential limit state is set, the stable differential state cannot be secured in the end during low-speed turning. In other words, a small turn becomes ineffective during low-speed turning, a so-called chattering phenomenon occurs in which the differential limiting state and the differential state are alternately switched, the maneuverability is degraded, and the differential device 1 is caused by an impact during chattering.
00 and its peripheral devices are adversely affected. For this reason, it is very difficult to set the urging force. For example, in a competition vehicle that is premised on sports traveling, the urging force of the elastic member 112 is set to be high while sacrificing the maneuverability at low speed turning to some extent. The actual condition is such that a sufficient differential limiting state can be obtained at high load.

An object of the present invention is to increase the friction pressure contact area of the clutch plate so that a sufficient differential limiting action can be obtained even under a high load, and the differential state and the differential limited state can be appropriately switched. It is to provide a differential device.

[0011]

Means for Solving the Problem and Its Action The applicant of the present invention has a left-right asymmetric structure in which the number of clutch plates and / or the outer diameter is different as the clutch means arranged on both sides in the axial direction of both pressure rings. The present invention has been completed based on the idea that a structure can be adopted.

A differential device according to the present invention comprises a differential case which is rotated about the left and right axles by a driving force from an engine, and a left and right pair which is movable in the axle direction and is relatively non-rotatable in the differential case. And a pair of pinion gears rotatably mounted on the pinion shaft, the left and right axles, the pinion shaft being orthogonal to the axle with the shaft ends held between the pressure rings. A pair of left and right side gears respectively provided at the shaft ends so as not to rotate relative to each other, and a pair of left and right side gears that engage with the pinion gear on both sides of the pinion gear, and are arranged on both sides in the axial direction of the pressure rings. By limiting the relative rotation between the differential case and the side gears, a pair of left and right wheels can be used to limit the differential between the left and right axles. A pitch means, and left and right pair of clutch means which gave a difference in number of sets and / or the outer diameter of the clutch plate between the two clutch means, via said clutch means
Without force, the biasing means that biases both pressure rings in the direction in which the clearance between both pressure rings becomes narrower, and the increase in the relative rotational torque between the pinion shaft and the differential case during differential operation causes Operation means for operating the pressure ring against the urging force of the urging means and operating the clutch means in a direction in which the clearance increases.

In this differential device, when the left and right wheels have the same rotational resistance, the pinion gear, the side gear, the pinion shaft, and the pressure ring rotate integrally with the differential case, so that the left and right wheels have the same speed. Although the wheels rotate, if both wheels have different rotational resistances, the pinion revolves while meshing with the side gear due to part of the rotational force that acts on the differential case, and the rotational speed of the wheel with less rotational resistance has the greater rotational resistance. The differential state becomes faster than the rotation speed of the side wheels, or the relative rotation between the side gear and the differential case is limited via the clutch means, and part of the rotational torque that acts on the differential case is distributed to the wheel side with large rotational resistance. It is switched to the differential limited state.

More specifically, when the left and right wheels have different rotational resistances, the operating means operates in a direction in which the clearance between the pressure rings increases in accordance with the relative rotational torque between the pinion shaft and the differential case. Power
Although it acts on both pressure rings, if the operating force by this operating means is smaller than the biasing force by the biasing means for reducing the clearance, the clearance does not change and a normal differential state is obtained. When the force becomes larger than the urging force, the clearances of both pressure rings correspondingly increase, the clutch plates of the clutch means are frictionally pressed against each other, and the differential between the left and right axles is limited.

When the left and right wheels have different rotational resistances,
According to the relative rotational torque between the pinion shaft and the differential case by the operating means, the operating force in the direction in which the clearance between the pressure ring and the ring facing surface increases acts on the pressure ring, but the operating force by this operating means is When the force is less than the biasing force of the biasing means to reduce the clearance, the clearance does not change and the normal differential state is obtained. When the clearance is greater than the biasing force, the pressure ring and the ring face accordingly. The clearance between the surfaces increases, the clutch plates of the clutch means are frictionally pressed against each other, and the differential between the left and right axles is limited.

Further , as the urging means, a clutch means is provided.
Without pressing through the
A biasing means for biasing the shirring is provided. That
Therefore, even if the biasing force of the biasing means is set high, the clutch means
The clutch plates do not come into friction contact,
The timing of switching to the motion restriction state depends on the operating force of the operating means.
Since it depends only on the biasing force of the biasing means,
By properly setting the biasing force of the means, it is possible to
In addition, a differential state can be reliably obtained, and turning at high speed and high load
Configured to ensure a limited differential state in some cases
It becomes possible to do.

Further, since the number of sets of clutch plates and / or the outer diameter is made different between both clutch means, the number of sets of clutch plates and the outer diameter are adjusted according to the shape of the differential case, so that the diff case is provided. The clutch plate can be installed without gaps in the differential case while preventing the formation of a thick, wasted part, and the area of the friction pressure contact part of the clutch plate is increased as much as possible to provide sufficient differential limiting even under high load. The action will be obtained.

Here, the diameter of the clutch plate is made different between the left and right clutch means, and the spline for fitting the clutch plate in the differential case so as to be axially movable and relatively non-rotatable. The pitch of the spline of the clutch plate may be set to be larger than the pitch of the spline of the large diameter clutch plate. In other words, the portion of the differential case where the small diameter clutch plate fits is the small diameter and the inner side of the differential case, and the workability of the processing of the spline for this portion is not very good, so the pitch of the small diameter clutch plate is The pitch is set to be larger than the pitch of the large-diameter clutch plate, so that the labor for processing the spline for the differential case can be saved.

At least one inner diameter of the pressure ring may be set to be larger than that of the side gear. In this case, since the inner diameter of the at least one pressure ring is set to be larger than that of the side gear, the pressure ring can be configured to be thin in the axial direction,
The number of clutch plates that can be accommodated can be increased accordingly. Although only one inner diameter of the pressure ring may be set larger than that of the side gear, the inner diameter of the left and right pressure rings should be set larger than that of the side gear in order to maximize the number of clutch plates to be accommodated. Is preferred.

It is preferable that the sleeve portion of the side gear is provided with a collar which is fitted so as not to be relatively rotatable, and the clutch plate is fitted to the collar so as to be axially movable and not relatively rotatable. That is, it is possible to form a spline or the like on the sleeve portion of the side gear, and assemble the clutch plate so as to be axially movable and relatively non-rotatable, but forming the spline up to the gear portion of the side gear is a process. Since this is difficult, it is preferable to assemble a collar made of a separate member to the sleeve portion of the side gear and fit the clutch plate on the sleeve.

Further, in this case, it is preferable that the collar has a diameter substantially the same as that of the side gear and a diameter smaller than the inner diameter of the pressure ring, and one end of the collar is inserted into the pressure ring. With this structure, it is possible to reliably prevent the clutch plate from coming off from the collar on the gear portion side of the side gear.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, the differential device 10 includes a differential case 1 that is rotated by a driving force from an engine about left and right axles 1 as rotation centers.
1 and a pair of left and right pressure rings 12 provided in the differential case 11 so as to be movable in the axial direction and non-rotatable relative to each other.
L, 12R, a pinion shaft 13 provided orthogonally to the axle 1 with the shaft ends held between the pressure rings 12L, 12R, and at least one pair of pinion gears 14 rotatably provided on the pinion shaft 13. , A pair of left and right side gears 15L and 15R provided on the shaft ends of the left and right axles 1 so as to be relatively non-rotatable, respectively.
4, a pair of left and right side gears 15L and 15R meshing with the pinion gear 14 on both sides of 4 and both pressure rings 12L and 12R are arranged on both sides in the axle direction.
A pair of left and right clutch means 16L, 16R capable of limiting the differential between the left and right axles 1 by limiting the relative rotation between the differential case 11 and the side gears 15L, 15R, respectively. One pair of left and right clutch means 16L, 16R having a different number and / or outer diameter of the plates 31L, 32L and the clutch plates 31R, 32R, and the pressure rings 12L, 12
Biasing means 18 for urging both pressure rings 12 in the direction in which the clearance 17 between R becomes narrower, and both pressure rings 12L, 12L, in response to an increase in the relative rotational torque between the pinion shaft 13 and the differential case 11 during differential operation.
It is provided with an operating means 19 for operating the pressure ring 12 against the urging force of the urging means 18 and operating the clutch means 16L, 16R in a direction in which the clearance 17 between the 12Rs increases.

The differential case 11 is divided into a lid member 20 and a case body 21, and the lid member 20 is fixed to a flange portion 22 formed at the left end of the case body 21. A ring gear 23 is fixed to the flange portion 22 on the side opposite to the lid member 20, and the ring gear 23 is meshed with a drive pinion 3 provided on a drive shaft 2 extending from the engine. In addition, the shaft ends of the left and right axles 1 are coaxially inserted through the differential case 11 through the lid member 20 and the right wall of the case main body 21, and the differential case 11 includes the drive pinion 3 and the ring gear 23. It is configured to be rotationally driven around the axle 1 by the driving force from the engine.

As shown in FIGS. 1 to 5, the case main body 21
The inner diameter of the left part is larger than the inner diameter of the right part, and a plurality of spline grooves 24L extending in the axle direction are provided in the left part of the inner peripheral surface of the case body 21 in the circumferential direction at intervals of, for example, 9 °. And a plurality of spline grooves 24R extending in the axle direction are formed in the right portion at a pitch of every 45 ° in the circumferential direction. The pitch of both spline grooves 24L and 24R can be set arbitrarily. Also, both spline grooves 24L, 2
4R can have the same pitch, but since the spline groove on the back side of the case body 21 is not very workable, the pitch of the spline groove 24R is set larger than the pitch of the spline groove 24L. The case main body 21 is configured so as to save labor.

Inside the case main body 21, a pair of left and right ring-shaped pressure rings 12L and 12R are provided with the inner surfaces of the partially spherical surfaces facing each other. Spline teeth 25L that engage with the spline groove 24L are formed on the outer peripheral surface of the left pressure ring 12L, and spline teeth 25R that engage with the spline groove 24R are formed on the outer peripheral surface of the right pressure ring 12R. The pressure ring 12 is provided in the case main body 21 so as to be movable in the axial direction and non-rotatably by the engagement of the spline teeth 25L, 25R and the spline grooves 24L, 24R. The size and shape of the differential case 11 can be arbitrarily set according to the vehicle to which it is applied. Also, the spline grooves 24L and 24R and the spline teeth 25L and 25R
Is the pressure ring 12 with respect to the differential case 11.
As long as the L and 12R can be guided in the axial direction so as not to rotate relative to each other, the L and 12R can be formed in an arbitrary cross-sectional shape and the number thereof can be set arbitrarily.

A substantially cross-shaped pinion shaft 13 is provided in a gear chamber 26 formed between the pressure rings 12L and 12R, and the pinion shaft 13 has the axle 1
Four shaft portions 13a extending in the direction orthogonal to are formed, and a pinion gear 14 is rotatably supported on each shaft portion 13a. The number of pinion gears 14 can be set arbitrarily, but at least one pair is provided.

A cam portion 27 is formed at each axial end of the pinion shaft 13, and a cam groove 28 is formed at each of the facing sides of the peripheral walls of both pressure rings 12 so as to correspond to each cam portion 27. 13 is each shaft portion 1
The cam portion 27 of 3a is supported in the gear chamber 26 by being sandwiched between the cam grooves 28 of both pressure rings 12. The operation means 19 is composed of the cam portion 27 and the cam groove 28.
Is configured, which will be described later.

In the gear chamber 26, the pinion gear 14 is sandwiched, and the left and right sides which mesh with the pinion gear 14 on both sides thereof are provided.
A pair of side gears 15L, 15R is provided, and the left and right axles 1 penetrate the pressure rings 12L, 12R and are thrust into the gear chamber 26, respectively.
L and 15R are connected to the shaft ends of the left and right axles 1 by spline fitting or the like such that they cannot rotate relative to each other. A sleeve portion 15a extending outward from the pressure rings 12L and 12R along the axle 1 is provided on both side gears 15L and 15R.
And the left and right side gears 15L and 15R are integrally formed.
The spline teeth 29 are formed on substantially the entire length of the sleeve portion 15a of the left side gear 15, the collar 30 is spline-fitted relative to the sleeve portion 15a of the left side gear 15L so as not to rotate relative to each other, and the collar 30 extends in the axle direction in the outer peripheral portion. The spline teeth 30a are formed over the entire length.
The sleeve portion 15a of the left side gear 15L and the collar 30 may be connected to each other via a key and a key groove or a groove and a protrusion instead of spline fitting if they cannot rotate relative to each other. You may connect by welding etc.

Clutch means 16L is externally mounted on the sleeve portion 15a of the left side gear 15L via the collar 30 on both sides of the pressure rings 12L and 12R in the axial direction, and the sleeve portion 15a of the right side gear 15R.
The clutch means 16R is directly mounted on the exterior.

The left clutch means 16L has first clutch plates 31L and second second clutch plates 32L arranged alternately, and the first clutch plates 31L are arranged in the axial direction via the spline grooves 24L of the differential case 11. The second clutch plate 32 is movably and relatively non-rotatably fitted into the differential case 11, and the second clutch plate 32 is provided with a collar 30 on the left side gear 15L.
The sleeve portion 15a is fitted onto the sleeve portion 15a so as to be movable in the axle direction and not relatively rotatable. Right clutch means 16R
Is a first clutch plate 31R and a second second clutch plate 32R.
Are alternately arranged, the first clutch plate 31R is fitted in the diff case 11 so as to be movable in the axle direction through the spline groove 24R of the diff case 11 and not relatively rotatable, and the second clutch plate 32R is provided on the right side. The side gear 15R is externally fitted to the side gear 15R so as to be movable in the axial direction and not relatively rotatable.

Then, both clutch means 16L, 16R are operated by the operating means 19, and the clutch plates 31L, 3L are
When 2L and the clutch plates 31R and 32R are pressed against each other, depending on the frictional force generated between the clutch plates,
The relative rotation between the differential case 11 and the side gears 15L and 15R is restricted.

Here, the feature of the present invention is that the clutch plates 31L, 32L and the clutch plates 31R, 32R have a different number of sets and / or outer diameters so that the differential case 11 has no waste space and a clutch. The point is that the plate is provided and the area of the friction pressure contact portion of the clutch plate is set as large as possible so that a sufficient differential limiting action can be obtained even under a high load. Specifically, as shown in FIG. 1, the clutch plate 31
The outer diameters of R and 32R are configured to be smaller than the clutch plates 31L and 32L, and the number of clutch plates 31R and 32R is set to be larger than the number of clutch plates 31L and 32L. However, the diameter and the number of clutch plates can be arbitrarily set according to the shape of the differential case 11, and the left and right clutch means 16 can be used.
The difference in either the diameter or the number of sheets between L and 16R is within the scope of the present invention.

The inner diameter D1 of the pressure ring 12L is set to be slightly larger than the outer diameter D2 of the gear portion 15b of the side gear 15L, and preferably to be slightly larger than the outer diameter D3. Further, in order to prevent the second clutch plate 32L from falling off from the collar 30 toward the gear portion 15b side, the outer diameter D4 of the collar 30 is configured to be slightly larger than the outer diameter D3 of the side gear 15L, and the pressure ring. The inner diameter D1 of 12L is configured to be slightly larger than the outer diameter D4 of the collar 30, and by inserting the end of the collar 30 into the pressure ring 12L, the second clutch plate 32L is prevented from falling off.

By thus setting the inner diameter of the pressure ring 12L to be larger than those of the side gear 15L and the collar 30, the pressure ring 12L is made thinner in the axle direction than the conventional one, and the pressure ring 1
The outer end surface in the axial direction of 2L and the outer end surface in the axial direction of the gear portion 15b of the side gears 15L and 15R are made substantially flush with each other, and the clutch plates 31L and 3L of the clutch means 16L.
2L can be arranged as close as possible to the gear portion 15b, and the number of assembled clutch plates 31L and 32L is increased by that amount, and the friction pressure contact portion of the clutch plates 31L and 32L is increased to provide a sufficient difference even under high load. You will get a motion restriction effect.

In this embodiment, the left side gear 15
Although the collar 30 is provided only on L, the right side gear 15
It is also possible to provide a color for R and configure it in the same manner as on the left side. Further, although the side gear 15L and the collar 30 are separately configured, they may be integrally configured. However, since the second clutch plate 32L is movably supported in the axial direction with respect to the sleeve portion 15a, a spline is formed on the outer peripheral portion of the sleeve portion 15a, but the sleeve portion 15a is formed near the gear portion 15b. Since it becomes difficult to form the spline and the number of clutch plates 31L and 32L that can be assembled is reduced accordingly, the spline pitch is set to be the same as the tooth pitch of the side gear 15L, and the spline pitch is set continuously from the tooth of the side gear 15L. It is preferable to form spline teeth extending outward in the axial direction.

A groove portion 42 is formed in the right wall portion of the lid member 20 and the case body 21, and a plate for urging the clutch plates 31L and 32L in the groove portion 42 on the left side of the left clutch means 16L toward the pressure ring 12L side. A spring 33L is provided, and a disc spring 33R for urging the clutch plates 31R, 32R toward the pressure ring 12R is provided in the groove 42 on the right side of the right clutch means 16R. The disc springs 33L and 33R are
It is provided for the purpose of eliminating the play between the 32L and the clutch plates 31R and 32R, and is set to such an urging force that a frictional force hardly acts between the clutch plates. However, the disc springs 33L and 33R are the clutch means 16
If L and 16R can be assembled without substantial play, they may be omitted. Further, in the present embodiment, the disc spring 33 is accommodated in the groove portion 42 in order to increase the number of clutch plates as much as possible, but it is also possible to provide the disc spring 33 without forming the groove portion 42.

A biasing means 18 is provided between the pressure rings 12L and 12R for biasing the pressure rings 12L and 12R toward each other. Specifically, the pressure ring 12
A housing hole 34 is formed in L between the shaft ends of the adjacent shaft portions 13a of the pinion shafts 13, and a rod member 35 that penetrates the pressure ring 12L and is screwed into the pressure ring 12R is attached to the housing hole 34. Has been done. The rod member 35 includes both pressure rings 12L and 1L.
Even when the 2Rs are closest to each other, that is, when the clearance 17 between the pressure rings 12L and 12R is minimized, the length is set so as not to protrude outside the pressure ring 12L, and the end of the rod member 35 has a collar portion. 36
Are formed. In the accommodation hole 34, the rod member 3
An elastic member 37 made up of a compression coil spring is installed on the outer casing 5, and both pressure rings 12L and 12R are constantly urged by the urging force of the elastic member 37 in a direction toward each other via the rod member 35.

[0038] Incidentally, the biasing means 18, both pressure rings 12L, 12R clutch means 16L, another is configured to be urged in a direction of approaching is to <br/> have Runode without using 16R, any It is possible to provide an arbitrary number of the constituents at arbitrary positions of both pressure rings 12L and 12R. In addition, the elastic member 3 including a compression coil spring
Instead of 7, an elastic member made of a disc spring, synthetic rubber, or the like may be used, or a tension spring or the like may be used to pull both the pressure rings 12L and 12R in directions toward each other. Furthermore, the differential case 11 and the pressure ring 1
It is also possible to provide a biasing means between 2L and 12R.

Further, as described above, when the urging means 18 is provided between the shaft ends of the pressure rings 12L and 12R adjacent to the pinion shaft 13, it is possible to arrange them in the dead space between the shaft ends. The pressure rings 12L, 12R and the diff case 11 can be made small in size in the radial direction, and the shaft end of the pinion shaft 13 is extended to the vicinity of the inner surface of the diff case 11 so that the cam portion 27 and the cam groove of the operation means 19 will be described below. Since it is possible to increase the contact area with 28, it is possible to effectively prevent the wear and damage of these members due to the relative rotational torque acting between the cam portion 27 and the cam groove 28, and improve the durability of the differential device. .
However, it is also possible to provide the rod member 35 of the urging means 18 so as to be located on the outer side of the shaft end of the pinion shaft 13 of the pressure rings 12L and 12R. Further, although it is preferable to provide such biasing means 18, the biasing means 18 may be omitted so that the left and right pressure rings 12L and 12R are biased toward each other by the disc springs 33L and 33R. The present invention can be similarly applied to the configured differential device.

As shown in FIGS. 3 and 6, the operating means 19 includes a cam portion 27 provided at the shaft ends of the four shaft portions 13a of the pinion shaft 13 and both pressure rings 12L, 1L.
The cam grooves 28 formed on the facing portions of 2R. The cam portion 27 has a pair of operation surfaces 38 formed in a substantially C-shape that is mirror-symmetrical with respect to an axle orthogonal plane including the center of the shaft portion 13a, and an operation surface 38 opposite to the operation surface 38 with the center of the shaft portion 13a interposed therebetween. The contact surface 39 is formed on the side and extends substantially in the axial direction. The cam groove 28 is formed in a substantially right-angled triangle shape with an inclined cam surface 40 having a shape adapted to the operation surface 38 and a locking surface 41 having a shape adapted to the contact surface 39.

Then, from the state shown in FIG. 6A, the pinion shaft 13 is moved to the pressure rings 12L, 12R.
On the other hand, when a slight relative rotation is performed upward in FIG. 6A, both pressure rings 1 are rotated as shown in FIG. 6B.
2L and 12R move in a direction in which they are separated from each other via the operation surface 38 and the inclined cam surface 40, but when a slight relative rotation is attempted downward in FIG. 6A, the contact surface 39
Is locked to the locking surface 41, and both pressure rings 12
The relative rotation between the L and 12R and the pinion shaft 13 is restricted. However, as the operation means 19, any structure can be adopted as long as it can be operated in the direction in which the pressure rings 12L and 12R are separated from each other by the relative rotational torque between the pinion shaft 13 and the differential case 11. For example, as illustrated in the prior art section,
As the cam portion 27, a substantially quadrangular or substantially rhombic cam portion 27 having one diagonal line arranged in the substantially axial direction is formed, and as the cam groove 28, a substantially V-shaped cam groove adapted to the cam portion is formed. May be adopted.

Next, the operation of the differential device 10 will be described. In this differential device 10, if the left and right wheels have the same rotational resistance, the pinion gear 14 and the side gear 15
The L, 15R, the pinion shaft 13, and the pressure rings 12L, 12R rotate integrally with the differential case 11, and the left and right wheels rotate at the same speed.

When the rotational resistance of one wheel decreases during forward traveling, basically, part of the rotational force acting on the differential case 11 causes the pinion gear 14 to revolve while meshing with the side gears 15L and 15R. The wheel on the side with less resistance has a higher rotational speed than the wheel on the side with large rotation resistance, but at the time of high speed and high load, the relative rotation between the side gears 15L, 15R and the differential case 11 causes the clutch means 16L. , 16R clutch plate 31L,
The differential limiting state is limited by the frictional pressure contact force between the 32Ls and the clutch plates 31R and 32R, so that the maneuverability at the high speed and the high load can be sufficiently ensured while improving the turning performance at the low speed.

More specifically, when a difference occurs in the rotational resistances of the left and right wheels during forward traveling, as shown in FIG. 6 (a), the operating means 19 is used to move the pinion shaft 13 and the differential case 11 relative to each other. A rotation torque P is generated, and the relative rotation torque P causes an operation force in a direction in which the pressure rings 12L and 12R are separated from each other via the operation surface 38 of the cam portion 27 and the inclined cam surface 40 of the cam groove 28. F acts on both pressure rings 12L and 12R, and FIG.
As shown in (b), when the pinion shaft 13 and the differential case 11 try to rotate relatively slightly, the cam portion 27
When the contact position between the operation surface 38 and the inclined cam surface 40 of the cam groove 28 is displaced, the clearance 17 tends to increase.

On the other hand, both pressure rings 12L, 12
Since the urging force that tries to bring them closer to each other is constantly acting on R, the operating force F of the operating means 19 is applied.
6 is smaller than the urging force of the urging means 18,
As shown in FIG. 6A, when the minimum clearance 17 is maintained and the differential state is established and the operating force F becomes larger than the biasing force, as shown in FIG. 6B, the clearance 17 is changed according to the force difference. Becomes bigger, both pressure rings 1
The clutch plates 31L and 32L and the clutch plates 31R and 32R are pressed by the side surfaces of the 2L and 12R, respectively, and the clutch plates are frictionally pressure-contacted to each other, whereby the differential limiting state is established.

Further, in this differential device 10, the pressure rings 12L and 12R are biased toward each other by the biasing means 18 without passing through the clutch means 16L and 16R. The timing for switching to the differential limiting state depends only on the operating force F of the operating means 19 and the biasing force of the biasing means 18, and the biasing means 1
By properly setting the urging force of No. 8, a differential state can be surely obtained at low speed turning, and a differential limited state can be surely obtained at high speed and high load turning. Is possible.

On the other hand, when the rotational resistance of one of the wheels is reduced during reverse travel, even if a relative rotational torque is generated between the pinion shaft 13 and the differential case 11, the relative rotational torque is generated by the contact surface 39 of the cam portion 27. Since the cam surface is locked by the locking surface 41 of the cam groove 28 and the relative minute rotation between the both is restricted, the minimum clearance 17 is maintained and the differential limiting state is not achieved. However, you can have us when reverse driving <br/>, similarly to the time of forward traveling, it is also possible to configure the switched and the differential state and the differential limited state.
In this case, for example, as the operating means 19, the cam portion is formed in a rhombic shape or a square shape as described above, and the cam groove is formed in a substantially V-shape suitable for the cam portion.

[0048]

The differential device according to the present invention basically operates in the same manner as a conventional differential device having a differential limiting function, but the number of clutch plate sets between both clutch means is different. And / or because the outer diameters are different, it is possible to install the clutch plates without any gap by adjusting the number and size of the clutch plates according to the shape of the differential case.
By increasing the area of the friction pressure contact portion of the clutch plate as much as possible, a sufficient differential limiting action can be obtained even under high load.

As biasing means, clutch means is used.
Pressure in a direction that reduces the clearance without
Is equipped with a biasing means for biasing the ring.
From the differential limiting state to the operation of the operating means
Since it depends only on the force and the biasing force of the biasing means,
By setting the urging force of the urging means appropriately, during low speed turning
The differential state can be reliably obtained at high speed and high load.
Make sure to obtain the limited differential state when turning.
It becomes possible to configure.

Here, a small diameter clutch plate is provided for the spline for allowing the left and right clutch means to have different diameters of the clutch plates, and for fitting the clutch plates in the differential case so as to be axially movable and relatively non-rotatable. If the pitch of the splines is set to be larger than the pitch of the splines of the large-diameter clutch plate, it is possible to save the labor of processing the splines for the differential case.

When the inner diameter of at least one of the pressure rings is set to be larger than that of the side gear, the pressure ring can be made thinner in the axial direction, and the number of clutch plates that can be accommodated is increased accordingly, and the clutch plates can be increased. It is possible to increase the frictional pressure contact portion and improve the differential limiting action.

When the sleeve portion of the side gear is provided with a collar that is fitted so as not to rotate relative to it, and the clutch plate is attached to this collar so as to be axially movable and not relatively rotatable, a spline is formed up to the gear portion of the side gear. This is preferable because the number of clutch plates to be assembled can be increased as much as possible. Also, if the collar has a diameter substantially the same as that of the side gear and is smaller than the inner diameter of the pressure ring, and one end of the collar is inserted into the pressure ring, the clutch plate will not come off from the collar on the gear side of the side gear. It can be surely prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a differential device (cross-sectional view taken along the line I-I in FIG. 2).

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a front view of the pressure ring and members assembled to the pressure ring.

FIG. 4 is a side view of the pressure ring and members assembled to the pressure ring.

FIG. 5 is a side view of the differential case.

FIG. 6 is an explanatory view of the operation of the operating means.

FIG. 7 is a cross-sectional view of a conventional differential device.

FIG. 8 is a cross-sectional view of a differential device having another structure according to the related art.

FIG. 9 is a cross-sectional view of the differential device previously filed.

[Explanation of symbols]

1 axle 2 drive shaft 3 drive pinion 10 Differential device 11 Differential case 12L pressure ring 12L pressure ring 13 Pinion shaft 13a Shaft 14 pinion gear 15L side gear 15R side gear 15a Sleeve part 15b Gear part 16L clutch means 16R clutch means 17 clearance 18 Biasing means 19 Operating means 20 lid member 21 case body 22 Flange 23 Ring gear 24L Spline groove 24R Spline groove 25L spline teeth 25R spline teeth 26 gear chamber 27 cam section 28 Cam groove 29 Spline tooth 30 color 30a spline teeth 31L clutch plate 32L clutch plate 31R clutch plate 32R clutch plate 33L disc spring 33R disc spring 34 accommodation hole 35 rod member 36 Collar 37 Elastic member 38 Operation surface 39 Abutment surface 40 Inclined cam surface 41 Locking surface

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F16H 1/44 B60K 17/20

Claims (5)

(57) [Claims] 1. A differential case which is rotated by a driving force from an engine about left and right axles as a center of rotation, and a pair of left and right pressure rings which are provided in the differential case so as to be movable in the axle direction and non-rotatable relative to each other. A pinion shaft provided orthogonally to the axle with the shaft end held between the pressure rings, and at least one rotatably provided on the pinion shaft.
A pair of pinion gears, a pair of left and right side gears provided at the shaft ends of the left and right axles so as not to rotate relative to each other, and a pair of left and right side gears that sandwich the pinion gear and mesh with the pinion gears on both sides thereof; Located on both sides of the ring in the axial direction,
A pair of left and right clutch means capable of limiting the differential between the left and right axles by limiting the relative rotation between the differential case and the side gear, and a difference in the number of clutch plates and / or the outer diameter between the clutch means. A pair of left and right clutch means, a biasing means for biasing both pressure rings in a direction in which the clearance between both pressure rings is narrowed without using the clutch means, and between the pinion shaft and the differential case during differential operation. And an operating means for operating the pressure ring against the biasing force of the biasing means to actuate the clutch means in a direction in which the clearance between the pressure rings increases in accordance with an increase in the relative rotational torque of the pressure ring. Differential. 2. A spline for allowing a clutch plate to have a different diameter between the left and right clutch means and for fitting the clutch plate in the differential case so as to be axially movable and non-rotatable relative to each other. The differential device according to claim 1, wherein the pitch of the spline of the clutch plate is set to be larger than the pitch of the spline of the large diameter clutch plate. 3. The differential device according to claim 1, wherein the inner diameter of at least one of the pressure rings is set to be larger than that of the side gear. 4. The collar according to claim 1, wherein the sleeve portion of the side gear is fitted so as to be relatively non-rotatable, and the clutch plate is fitted to the collar so as to be axially movable and relatively non-rotatable. The differential device according to item 1. 5. The differential device according to claim 4, wherein the collar has a diameter substantially the same as that of the side gear and a diameter smaller than the inner diameter of the pressure ring, and one end portion of the collar is inserted into the pressure ring.