JPS639769A - Differential device associated with differential limiting mechanism - Google Patents

Abstract

PURPOSE:To prevent abrasion of a sleeve, by making the sleeve at the inside of a spring plate for pressing a frictional clutch movable in the circumferential direction and employing a smoothly curved face in the border section between the inclined face sleeve and the pushing sideface. CONSTITUTION:A frictional clutch 3 being pressed by a spring plate 2 and a sleeve 6 are provided in a clutch case 1 and a steel ball 9 is engaged in a through-hole 9 at a boss section 7. The sleeve 6 is slidable in the circumferential direction and a smoothly curved face is employed in a border face 15 between an inclined face of sleeve 10 and a pushing sideface 11. Consequently, a local and axial abrasion groove is not formed in the sleeve through the contact with the steel ball, thereby the durability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION A. OBJECTIVE OF THE INVENTION a. Industrial Application The present invention relates to a differential limited differential device used in automobiles and other vehicles 2, and particularly relates to a limited differential differential device used in automobiles and other vehicles. This invention relates to a differential device with a differential limiting mechanism that can be used with the '#'J limit.

b. Prior Art A differential device for an automobile or other vehicle rotates both wheels at the same rate when the vehicle is on both roads, and when the vehicle is running on both roads, the angular velocity of both wheels is changed by the differential to ensure smooth running. In addition, if one wheel enters a place with a small coefficient of friction, such as muddy ground or frozen road surface, the differential can be limited by external means or other means to apply sufficient torque to the other wheel, making it possible to escape. It is something to do.

Therefore, the applicant of the present invention previously proposed a differential device with a differential limiting mechanism of a new configuration in Japanese Patent Application No. 61-97538. This is a differential device with a differential limiting mechanism that includes a friction clutch in the clutch booth that is pressed by the advancement of a spring plate, and a sleeve that is slidable toward the friction clutch via a fork that is actuated by an external means. An appropriate number of through holes are formed in the boss portion of the spring plate in the circumferential direction, and a movable body having a height greater than the depth of the through hole is engaged with each through hole.
On the outside of the sleeve, there is a sleeve slope that pushes the movable body of each through hole toward the clutch booth side when the sleeve is normally pulled out for differential use, and a sleeve slope that presses the movable body against the clutch case slope described below to lock the spring plate. The press for locking is provided with a recess on the side surface and a recess in which a part of the movable body can be held in order to release the lock when the sleeve for differential restriction is pushed in, and a part of the movable body is provided on the inside of the clutch booth. and a clutch booth slope that moves the movable body pushed by the sleeve slope toward the anti-friction clutch side in order to retract the spring plate when the sleeve for the normal differential is pulled out. be.

The differential device with a differential limiting mechanism configured as described above allows the driver to select and switch between normal differential and limited differential at any time, reliably, quickly, and smoothly. Furthermore, it was possible to prevent friction and heat generation at the contact portion between the fork pin and the sleeve, reduce the operating force required for switching, and aim to simplify and downsize the device.

C Problems to be Solved by the Invention Various prototypes and tests were conducted to commercialize the above structure, but the movable body was a steel ball, and the sleeve slope and A problem with pressing was found when the sides and the slope of the clutch booth on the inner circumference of the clutch booth were each made into an annular shape.

The first problem is that deep friction grooves are formed in the axial direction on the outer periphery of the sleeve, especially on the side surface when pressed, which impairs durability. The second problem is that the boundary between the sleeve slope and the side surface of the sleeve is damaged, which impairs durability. ! [When we conducted a durability test by repeatedly switching between normal differential and limited differential under the same conditions as the operating conditions of I can no longer do it. When we investigated the reason for this, we found that the first cause is that the sleeve can move only in the axial direction relative to the clutch booth, so the contact area between the sleeve and the steel ball repeatedly moves only in the axial direction, causing the sleeve to move in the axial direction. It was found that local wear grooves in the axial direction were formed by the steel balls. The second reason is that the boundary between the sleeve slope and the side surface for pressing is the boundary between machining the sloped peripheral surface for the sleeve slope and machining the outer peripheral surface for the side surface for pressing, so the boundary is at an angle. It was found that the corners of the m-sphere were damaged due to the axial movement of the m-sphere.

The present invention aims to solve the first and second problems mentioned above. That is, an object of the present invention is to prevent local wear grooves in the axial direction caused by the steel balls from forming on the outer peripheral surface of the sleeve, and to prevent damage from occurring at the boundary between the sleeve slope and the side surface. The objective is to significantly improve the durability of this type of differential gear.

Arrangement of the Invention (a) Means for Solving the Problems As shown in FIGS. A friction clutch (3) that is pressed by a friction clutch (3) and a sleeve (6) that can be slid toward the friction clutch via a fork (6) actuated by an external means (4) are provided. 7), form an appropriate number of through holes (8) in the circumferential direction, engage each through hole (8) with a W4 ball (9) having a height greater than its depth, and On the outer side, there is a sleeve slope (10) that pushes the steel R (9) of each through hole (8) toward the clutch booth side when the sleeve is normally pulled out for differential use, and locks the spring plate (2). Therefore, the W4 ball (9) is pressed and locked to the clutch case slope α → described later by the side surface (11), and when the sleeve is pushed in to limit the differential, the steel ball is used to release the locking) 9 ) is provided with a recess (121) that can hold a part of the steel ball (9), and a recess (+4) that can hold a part of the steel ball (9) and a recess (121) that can hold a part of the steel ball (9) on the inside of the clutch case (tl). In order to retract the spring plate (2) when the sleeve is pulled out, the steel ball (9) pressed by the sleeve slope (10i)
Clutch case slope (
14), the spring plate (2) is circumferentially fixed to the clutch case Tl), and the inner sleeve (6) is fixed to the clutch case Tl).
) is movable in the circumferential direction, and the sleeve slope (10)
And the push is the side (the boundary with the river), which is formed by forming the country into a smooth curved surface.

In the above RFT structure, the relationship between the sleeve (6) and the clutch case [1] is that there is a slight rotational difference between the two (+61 fl), so the sleeve (6) is directly inserted into the clutch case (1) as in the illustrated embodiment. However, a bush or the like may be interposed in between. The relationship between the spring plate (2) and the clutch case (1) is that the spring plate (2)
is movable in the axial direction and fixed in the circumferential direction, for example, the first
As shown in the figure, insert the pin (+6) into the clutch case [1]
or both [2
A slide pin, a slide key, a spline, etc. may be formed inside between 1+1i or in other parts.

The clutch case slope (14) is the slope as shown in the illustrated embodiment! The steel ball locking ring (14) shall be installed inside the clutch case (11), and it is desirable that the ring QQ be movable only in the circumferential direction. , clutch case (1) as shown
Retaining ring inside! J9) may be installed internally for positioning and locking, but it is also possible to screw a ring nut inside the clutch case (1) instead of the retaining ring α9). Although not shown, a thrust washer is interposed between the steel ball retaining ring (+81) and the retaining ring (+9)/ring nut, and the steel ball retaining ring 1181 and clutch goose f1
+ A bush may be interposed between.

In the figure, (A) is a differential carrier, and like a known differential device, it has a drive pinion (2υ) connected from the engine, and a ring gear and a differential case row that mesh with the drive pinion are fixed. Inside the differential case 123),
Pinion shirt) Rotatable differential pinion 1 around l→
25+ is thrown, and the differential box (A) is engaged with the pinion shaft (Tef side gear on both axle mounts perpendicular to the pinion shaft). is fork pin, 01) is fork pin groove, (
) is a spring.

b. Operation The operating state of the present invention will be described below. First, for a normal differential, the fork (5) is actuated by the cylinder (4) as an external means, and the sleeve (6) is moved to the anti-friction clutch side (as shown above the line X-X in Fig. 1). left side in the figure)
Pull it out. At this time, the steel ball (9) in the through hole (8) of the spring plate (2) is pushed toward the clutch case (1) by the sleeve slope (10) of the sleeve (6).
As shown in FIG. 3, the pressing member is further pressed against and locked on the side surface (Ill) of the clutch case slope (14).

By adjusting this steel ball (9), the spring plate (2
) is also locked in the reverse position on the anti-friction clutch side against the pushing force of the spring (to), so the friction clutch (3) is in an open state. Now, similar to known differentials, engine rotation and torque rotate and drive the differential box via the drive pinion @υ and ring gear (3), and the pinion shaft +24) causes the differential box to revolve. to allow normal straight-line driving and turning driving to be carried out smoothly.

On the other hand, if one wheel enters a place with a low coefficient of friction, such as a muddy or icy road, or if such road conditions are detected, the differential limiting (IC) is switched. 4) and the sleeve (6) via the piston/fork (5).
Just push it to the friction clutch side (right side in the diagram).

When pressing the sleeve (6), in the initial stage, the sleeve (6) is pressed from the side (6) as shown in FIG.
11), the steel ball (9) is pressed against and locked to the clutch case slope '14). Therefore, when the clutch case (1) is rotating while the vehicle is running or otherwise, the sleeve (6) is also rotating at the same time as the clutch case (1).

Therefore, when the 7 oak (6) is moved to push the sleeve (6), the fork pin contact comes into contact with all of the 7 oak pin grooves 6D of the sleeve (6), and the sleeve (6) is moved there.
6) Frictional rotation resistance torque is generated in the direction of stopping the rotation. However, in this state, the locking force between the sleeve (6) and the clutch case via mff+91 is still larger than the friction rotational resistance torque, so the sleeve (6)
remains at the same rotation as the clutch case (1).

When the sleeve (6) is further pushed in through the fork (5) and the fork pin, the state shown in Fig. 4 is reached; in this state, the spring plate (2) is connected to the friction clutch (3).
This is the position where the contact begins. Therefore, the pushing force of the spring (to) is divided between the #1 ball (9) and the friction clutch (3), so the locking force of the steel ball (9) on the sleeve (6) to the clutch case f11 is attenuated. .

When the locking force of the sleeve (6) becomes smaller than the friction rotational resistance torque, the sleeve (6) rotates slower than the clutch case [11], and a phase change occurs between the two (6H1). Therefore, the through hole (
The steel ball (9) in 8) now revolves around the outer periphery of the sleeve (6), and the same phase change as described above occurs between the sleeve (6) and @ball (9). Therefore, the steel ball (9
) will cover the entire circumference of the sleeve (6), so there will be no occurrence of local wear grooves in the axial direction on the outer circumference of the sleeve (6).

If the slope of the latch case (14) is a circumferentially movable steel ball locking ring (181V'C type) as in the illustrated embodiment, the change in phase between the sleeve (6) and the steel ball (9) , as the steel ball (9) rotates within its through hole (8), the #1 ball-retaining ring (1 uniform) that receives it rotates in the same direction. Therefore, both (9) and α interrogation have a phase difference. A change occurs, and the steel ball (9) hits the clutch case slope (1) of the steel ball locking ring.
4) Since contact is made over the entire inner circumference, no local wear grooves in the axial direction occur.

When the sleeve (6) is further pushed in, as shown below the line X--X in FIG. 1 and as shown in FIG.
) moves to a position inside the tlA sphere (9).

There, the steel ball (9) engages with the recess α, the locking state of the spring plate (2) via the steel ball (9) is released, and the spring plate (2) is
moves forward toward the friction clutch. Therefore, the friction clutch (
3) is in close contact with each other to limit differential movement, making it possible to drive and escape from muddy or frozen roads. In this state, f″1fI4 balls!
The locking force of the sleeve (6) due to 91 K has disappeared, and the friction rotational resistance torque between the fork pin (30) and the fork pin groove at has also disappeared, and the sleeve (6)
is in a free state in the circumferential direction.

Next, to release the limited differential state, shillings (4
) to the anti-friction clutch via the fork 1.5) to the state shown above the line X-X in Fig. side (left side in the diagram)
Just return it to . At the initial stage, as shown in Fig. 6, the movement of the sleeve (6) causes the sleeve slope (10) to move against the steel ball (
9) to the recess Q31 side of the clutch case il). At this time, while the vehicle is running, the clutch case (1)
is rotating, a reaction force of the sleeve (6) that resists the operating force of the fork (5) occurs, and the fork pin <3
Frictional rotational resistance torque is also generated at the contact portion between g) and the sleeve (6) on the inside of the 7-oakbin groove 0υ. This frictional rotational resistance torque causes the rotation of the sleeve (61) to be slower than the rotation of the clutch case (11), as described above, so that the steel ball (61), which is rotating at the same time as the clutch case (1), as described above.
9) revolves around the outer periphery of the sleeve (6), causing a change in phase. Further, in the case where the clutch booth slope θ is formed in the circumferentially movable steel ball locking ring (18) as in the illustrated embodiment, the ring q81 rotates in the circumferential direction and locks the steel ball (9) in the same manner as described above. ), a phase change occurs between 9 and 9. Therefore, even when the sleeve is pulled out, the sleeve slope (10), the pressing side ff1 (II), and the clutch case slope (14) all come into contact with the steel ball (9) over the entire circumference, so that the local axial direction No wear grooves occur.

Release of the limited differential state is achieved by further pulling out the sleeve (6). That is, by pulling out the sleeve (6),
Since #1R191 moves along the clutch case 88 + 04) to the anti-friction clutch side (left side in the figure), the spring plate (2) also moves backward accordingly. Therefore, the pressing force of the spring 0'2I on the friction clutch (3) is released, and a sufficient gap is created between the plates of the friction clutch (3). Next, press the sleeve (6) so that the side (11) is the recess of the clutch case (1)! A ball engaged with l4 (
9) Clutch case slope! 141 to press and lock. This state is the same as shown in Fig. 3 earlier, and since the spring plate (2) is locked by the steel ball (9), the friction clutch (3) is maintained in the open state, and the normal difference is Becomes a movement.

In the above case, by moving the steel ball (9) toward the anti-friction clutch side, the sleeve (
6) The locking force increases. Therefore, when the locking force becomes larger than the friction rotational resistance torque, the sleeve (6
) and clutch case (the rotation difference between 11 is eliminated, and both:
e+ +9+ is the same rotation. In addition, the steel ball (9) is pressed by the side surface (11), and the clutch case slope Q41
When the fork (5) is pressed and locked, the hydraulic pressure of the cylinder (4) is 1r OK, and the operating force of the fork (5) is lost, so the fork pin and the 7-oakbin groove 01)
The frictional rotational resistance torque that occurred during that time has become O.

Then, when switching from the normal differential to the limited differential and from the limited differential to the normal differential, the steel ball (9)
In both cases, the sleeve slope (10) of the sleeve (6) and the pressing pass through the boundary (15) with the side surface (river).In this case, in the present invention, this boundary (15) is formed into a smooth curved surface. Therefore, the steel ball (9) passes smoothly. Therefore, even if the boundary part (15) and the steel ball (9) come into contact, there is no generation of excessive Hertzian stress, and the boundary part (country No defects will occur.

Note that when the sleeve (6) is pushed in or pulled out, if the vehicle is stopped or the clutch case (1+) is not rotating, there will be no phase change in each direction as described above, but the fork (
The switching of the friction clutch (3) according to step 5) is similarly performed repeatedly.

C Durability Test As mentioned in the previous section on the problems to be solved by the invention, a durability test was conducted by repeatedly switching between normal differential and limited differential under the same conditions as in actual use. .

To compare them, first, the sleeve (6) and the clutch case (1) do not rotate in the circumferential direction, and the sleeve (6) and the clutch case (1) do not rotate in the circumferential direction.
6) If the boundary part α5) between the sleeve slope [10) and the side surface (11) is angular, as mentioned earlier, 1
After 120 repeated movements, a defect occurred at the boundary (15) and it became inoperable.

2nd K, 7. Although the league (6) and the clutch case (1) cannot rotate in the circumferential direction, the boundary part (15) formed into a smooth curved surface allows smooth operation even when the league (6) and clutch case (1) are moved repeatedly so, o o o times. The depth of the groove formed by the steel ball (9) on the sleeve (6) at that time was 0.18 m at the boundary where the maximum value appeared. Considering that it was O, OS at the 1620th repetition during the same test, it is presumed that there is a decrease in Hertzian stress due to groove formation and work hardening of the groove.

Thirdly, in the case where the sleeve (6) and the clutch case il) are movable in the circumferential direction as in the present invention, and the boundary portion (the country is formed into a smooth curved surface), the operation is smooth even after 40,000 cycles. Furthermore, the contact area between the steel ball (9) on the sleeve (6) at that time and the extremely slight change of 0°01 fl uniformly around the entire outer circumference without the above formation. This is because, as mentioned above, the sleeve (6) and the clutch case (1) are movable in the circumferential direction, and the boundary (I5) is a smooth curved surface, so the steel ball (9) is attached to the sleeve ( This is because the entire outer periphery of 6) is in contact, local wear is eliminated, and work hardening has also occurred, and it is assumed that there will be almost no further changes. , it was proved that the present invention is effective.

C. Effects of the Invention As is clear from the above description, the differential device with a differential limiting mechanism of the present invention has the following effects.

a. Local wear grooves in the axial direction due to contact with steel balls are not formed on the sleeve, and durability can be greatly improved. That is, this type of differential device with a differential limiting mechanism uses steel balls that come into contact with the sleeve slopes and sides of the sleeve. However, the sleeve slope/pressing method lacks durability because local wear grooves in the axial direction are formed on the side surfaces due to the repeated movement of the steel ball.

In contrast, in the present invention, the sleeve is movable not only in the axial direction but also in the circumferential direction. Therefore, when switching between normal differential and limited differential while the clutch case is in a rotating state, the circumferential phase of the contact portion between the sleeve and the steel balls is changed each time.

Therefore, since the contact portion with the steel ball extends over the entire outer circumference of the sleeve, local wear grooves in the axial direction can be prevented from forming, thereby significantly improving durability and maintaining smooth switching operation.

b Sleeve slope and pressing on the sleeve eliminates damage at the boundary with the side surface, greatly improving durability. That is, the boundary between the sleeve slope and the pressing side surface is the boundary between machining of the sloped surface for the sleeve slope and machining of the circumferential surface for the pressing side. As a result, the boundary portions are angular, making it difficult for the steel balls to move smoothly, and excessive Hertzian stress is generated between the steel balls and the steel balls, causing damage to the corners and impairing durability.

However, in the present invention, the boundary between the sleeve slope and the side surface is formed into a smooth curved surface. Therefore, in the present invention,
The W4 ball can smoothly pass through the boundary area and the switching operation is smooth. Furthermore, since excessive Hertzian stress is not generated at the boundary, breakage can be prevented and durability can be greatly improved.

C. If the clutch case slope is formed into a circumferentially movable steel ball locking ring as in the illustrated embodiment, the steel ball locking ring and The contact position of the steel ball changes its phase in the circumferential direction. Therefore, contact with the steel balls occurs over the entire inner periphery of the clutch case slope, preventing the formation of local wear grooves on the clutch case slope, and significantly improving durability.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Fig. 1 is a cross-sectional plan view of the entire device, Fig. 2 is an enlarged cross-sectional plan view of the main parts, Fig. 3,
FIG. 4, FIG. 5, and FIG. 6 are enlarged cross-sectional plan views of main parts in each operating state. Drawing code (1)...Clutch case, (2)...Spring plate, (3)...Friction clutch, (4)
...external means, (5)...7 oak, (6)...
Sleeve, (7)...Boss part, (8)...Through hole, (
9)...fsbL tro+...sleeve slope, (
11)... Pressing is on the side, (end... recess, α (to)...
・Concavity・ (+4...Clutch case slope, (15)
... Boundary part, (I ■ ... Steel ball locking ring, ■ ...
Fork pin, c3])...Fork pin groove, (to)
···spring.

Claims (1)

[Claims] [1] Inside the clutch case (1), there is a friction clutch (3) that is pressed by the forward movement of the spring plate (2), and a fork (5) that is operated by an external means (4) and slides toward the friction clutch side. A suitable number of through holes (8) are formed in the boss portion (7) of the spring plate (2) in the circumferential direction, and each through hole (8) is When pulling out the sleeve for normal differential use, the steel balls (9) in each of the through holes (8) are engaged with the outer part of the sleeve (6) to the clutch case side. The steel ball (9) is attached to the clutch case slope (14) described later for locking the pushing sleeve slope (10) and the spring plate (2).
A pressing side surface (2) for pressing and locking the sleeve, and a recess (12) in which a portion of the steel ball (9) can be engaged to release the locking when the sleeve is pushed in to limit the differential, and A recess (13) in which a part of the steel ball (9) can be engaged is provided on the inside of the clutch case (1), and a recess (13) for retracting the spring plate (2) when the sleeve for the normal differential is pulled out. Clutch case slope (14) that moves the steel ball (9) pushed by the slope (10) to the anti-friction clutch side
In the differential device with a differential limiting mechanism, the spring plate (2) is fixed to the clutch case (1) in the circumferential direction, and the sleeve (6) inside thereof is movable in the circumferential direction, and the spring plate (2) is fixed to the clutch case (1) in the circumferential direction. A differential gear with a differential limiting mechanism, characterized in that a boundary (15) between a sleeve slope (10) and a pressing side surface (11) is formed into a smooth curved surface.