JPH06249262A - Coupling device - Google Patents

Abstract

PURPOSE:To prevent the coupling force of a main clutch from influence of the dragging torque of a pilot clutch. CONSTITUTION:The small coupling force of a pilot clutch Pc is increased by means of a cam mechanism C, and a main clutch Mc is coupled by a pressure plate 22. The energization force of a belleville spring 23 provided on the right end of the main clutch Mc is transmitted to a left casing 2, through outer disks 18, inner disks 19, the pressure plate 22, a first cam ring 27, and a thrust bearing 35. The first cam ring 27 is rotated together with the pressure plate 22 and a second cam ring 33 by friction force received from the pressure plate 22, and hence the coupling force of the main clutch Mc is prevented from influence of the dragging torque of the pilot clutch Pc through the cam mechanism C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pilot clutch which is fastened by an actuator, cam means which is actuated by the fastening force of the pilot clutch, a pressing member which is driven by the cam means to move, and fastening by the movement of the pressing member. A main clutch, wherein the cam means
The first cam ring is constrained by the pilot clutch, the second cam ring is provided on the pressing member, and the rotating body is interposed between the first and second cam rings to convert the relative rotation of both cam rings into thrust. Connection device.

[0002]

2. Description of the Related Art Conventionally, as such a coupling device, Japanese Patent Laid-Open No.
Those described in Japanese Patent Application Laid-Open No. 219123 or Japanese Patent Application Laid-Open No. 4-107347 are known. These connecting devices are applied to the differential limiting mechanism in the differential of an automobile, and the differential limiting mechanism is controlled by engaging the main clutch with the engaging force of the pilot clutch.

[0003]

By the way, when an automobile equipped with the differential limiting mechanism is running straight at high speed, the engaging force is generated in the main clutch to limit the differential, so that the vehicle runs straight against a crosswind. It is possible to improve the property. However, even if the pilot clutch is engaged to engage the main clutch, the relative rotational speed difference between the input side and the output side of the cam mechanism is extremely small during straight traveling,
In some cases, the cam mechanism does not work sufficiently to obtain a proper differential limiting force. Therefore, as disclosed in Japanese Patent Laid-Open No. 4-92131, it is considered that the main clutch is provided with an urging means and the urging force pre-presses the main clutch to exert a necessary engaging force.

However, in the above case, the urging force of the urging means also acts on the cam mechanism, so that the responsiveness of the cam mechanism is increased more than necessary. As a result, when drag torque is generated in the pilot clutch due to the viscosity of oil, especially at low temperatures, the drag torque is transmitted to the main clutch via the sensitive cam mechanism, and an unnecessarily large differential limiting force is generated. There is a problem that ends up.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to regulate the operation of the cam mechanism by the drag torque of the pilot clutch to stabilize the engagement force of the main clutch.

[0006]

In order to achieve the above object, the present invention provides a pilot clutch that is engaged by an actuator, a cam means that is actuated by the engaging force of the pilot clutch, and a pressing force that is driven by the cam means to move. A first cam ring constrained by a pilot clutch, a second cam ring provided on the pressing member, and first and second members. In a coupling device including a rotating body that is interposed between cam rings and converts relative rotation of both cam rings into thrust, the pressing member and the first cam ring are connected to each other in order to generate a frictional force between the pressing member and the first cam ring. The first feature is that the urging means is provided to urge the members to abut each other.

In addition to the above-mentioned first feature, the present invention also provides:
A second feature is that the second cam ring is supported by the pressing member so as to be relatively movable, and a gap is formed between the pressing member and the second cam ring when the pilot clutch is not engaged.

In addition to the above-mentioned first or second characteristic, the present invention has a third characteristic that the urging means urges the main clutch in the engaging direction.

Further, in addition to any one of the above-mentioned first to third features, the present invention has a fourth feature in that a phase angle adjusting means for centering the first cam ring and the second cam ring with each other is provided. .

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 10 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a rear differential, and FIG.
2 is a sectional view taken along line 2-2 of FIG. 1, FIG. 3 is a sectional view taken along line 3-3 of FIG. 2, FIG. 4 is an enlarged view of an essential part of FIG. 1, FIG. 5 is a sectional view taken along line 5-5 of FIG. 6 is a sectional view taken along line 6-6 of FIG. 4, and FIG.
7 is a sectional view taken along line 7, FIG. 8 is a sectional view taken along line 8-8 in FIG. 4, and FIG.
And FIG. 10 is a partial perspective view of the cam mechanism.

FIG. 1 shows a rear differential D of an automobile equipped with a differential limiting mechanism, and its differential case 1
Is composed of a left casing 2, an intermediate casing 3, a center casing 4 and a right casing 5 which are axially divided into four parts and are integrally connected. A driven bevel gear 6 driven by meshing with a driving bevel gear (not shown) provided at the rear end of a propeller shaft extending in the vehicle front-rear direction is fixed to the center casing 4. The left casing 2 rotatably supports a left axle 7 connected to the left rear wheel, and the right casing 5 rotatably supports a right axle 8 connected to the right rear wheel.

As can be seen by referring also to FIG.
Inside the differential case 1, there is housed a planetary gear type differential device P that transmits the driving force input to the differential case 1 to the left axle 7 and the right axle 8 and absorbs the rotational speed difference between both axles 7 and 8. To be done. The differential device P includes a planetary gear carrier 9 spline-coupled to the right axle 8.
The planetary gear carrier 9 includes a pair of an outer planetary gear shaft 10 and an inner planetary gear shaft 11 which form a pair.
Three pairs are provided at 0 ° intervals.

The outer planetary gears 12 supported on the outer planetary gear shafts 10 ...
While meshing with the ring gear 13 formed on the inner circumference of
It is meshed with the inner planetary gears 14 supported on the inner planetary gear shafts 11. In addition to the outer planetary gears 12 ..., The inner planetary gears 14 also mesh with a sun gear 16 formed on the outer periphery of the right end of a sleeve 15 splined to the left axle 7.

Next, the center clutch Mc having the ring gear 13 and the sleeve 15 having the sun gear 16 are integrally connected to generate a differential limiting force.
The structure of is explained.

In FIG. 4, a plurality of main clutch outer discs 18 ... Are axially slidably supported on the serrations 17 formed on the inner periphery of the center casing 4. These main clutch outer discs 18 ...
A plurality of main clutch inner discs 19, which are alternately stacked with respect to each other, are axially slidably supported by serrations 20 formed on the outer periphery of the sleeve 15. An annular stopper plate 21 arranged on the right side of the right end main clutch outer disc 18 has its outer periphery supported by the serrations 17 of the center casing 4,
Sliding in the axial direction together with the main clutch outer disc 18 and the main clutch inner disc 19.
The slidable range of the stopper plate 21 is restricted to the range sandwiched by the pair of C clips 37 and 38 engaging with the serrations 17. On the other hand, an annular pressure plate 22, which will be described in detail later, is arranged on the left side of the left main clutch inner disc 19.

A disc spring 23 is interposed between the locking step 21 ₁ formed on the right side surface of the stopper plate 21 and the locking step 4 ₁ formed on the inner circumference of the center casing 4.
The disc spring 23 urges the stopper plate 21 in the leftward direction, that is, in the direction in which the main clutch outer disc 18 ... And the main clutch inner disc 19 ...
Thereby, a predetermined initial engagement force is generated in the main clutch Mc.

While the main clutch Mc is generating the initial fastening force, a stopper play 21 is provided between the outer periphery of the stopper plate 21 and the right C-clip 38.
Of which gap alpha ₁ is formed to allow the rightward movement, also a slight clearance alpha ₂ is formed to allow the leftward movement of the stopper play and 21 between the C-clip 37 of the outer periphery and the left stopper plate 21 Has been done. The gap α ₁ which allows the stopper play and the right movement of 21 is formed smaller than the gap between the right side surface of the stopper plate 21 and the left side surface of the planetary gear carrier 9, whereby the stopper is engaged when the main clutch Mc is engaged. Contact between the plate 21 and the planetary gear carrier 9 is avoided.

Next, the structure of the pilot clutch Pc for generating the engagement force on the main clutch Mc will be described.

In FIG. 4, a plurality of pilot clutch outer discs 25 ... Are axially slidably supported by the serrations 24 formed on the inner periphery of the intermediate casing 3. These pilot clutch outer discs 2
A plurality of pilot clutch inner discs 26, which are alternately superposed on the 5 ...
It is supported by a serration 28 formed on the outer periphery of the cam ring 27 so as to be slidable in the axial direction. On the right side of the rightmost pilot clutch outer disc 25, the pilot clutch outer disc 25 cooperates with the right side surface of the left casing 2.
An annular armature 29 is axially slidably supported so as to sandwich the pilot clutch inner disc 26.

On the other hand, a solenoid 31 is supported on the outer periphery of the left casing 2 via two ball bearings 30, 30. The solenoid 31 is energized by a command from a controller (not shown), and its magnetic force causes the armature 29 to move.
Of the pilot clutch outer disc 25 ... And the pilot clutch inner disc 26 ...
Conclude

As can be seen by referring to FIG. 5 together,
A plurality of pieces (for example, two or four pieces) are provided on the outer periphery of the armature 29.
Ball groove 29 ₁ ... is formed of pieces). Ball groove 29 ₁
... and a ball 36 in the serration 24 facing it
Are engaged with each other, whereby the armature 29 is prevented from rotating with respect to the intermediate casing 3 and can smoothly slide in the axial direction. Armature 29
The moving end to the right side of is restricted by a C clip 32 that engages with the serration 24, and this C clip 32 also functions as a fall-off preventing member for the balls 36. At this time, by forming smaller than the open end 32 ₁ of the gap β balls 36 ... diameter of the C-clip 32, the ball 36 ... falling off from the open end 32 ₁ is prevented.

Since the outer periphery of the armature 29 is locked to the side of the differential case 1 via the balls 36, the inertia of the first cam ring 27 is greater than that when the inner circumference of the armature 29 is locked to the side of the first cam ring 27. The moment can be reduced to prevent unnecessary engagement of the main clutch Mc, the load of the pilot clutch Pc can be reduced when the pilot clutch Pc is engaged, and the armature 29 can be prevented from swinging to rotate. Can be stabilized. Moreover, since the armature 29 and the differential case 1 are in contact with each other through the balls 36 having a small contact area, not only the armature 29 is smoothly moved in the axial direction, but also leakage of magnetic force lines is prevented and the solenoid 31 is provided. It is possible to prevent a decrease in the suction force of.

Next, the structure of the cam mechanism C for increasing the engaging force of the pilot clutch Pc and transmitting it to the main clutch Mc will be described.

As shown in FIGS. 3 and 4, the cam mechanism C comprises a first cam ring 27, a second cam ring 33, and a plurality of balls 34 .... The first cam ring 27 is supported on the outer periphery of the sleeve 15 so as to be relatively rotatable, and its left end face is supported by the right end face of the left casing 2 via a thrust bearing 35. The second cam ring 33 is axially slidably spline-coupled to the outer periphery of the sleeve 15, and the pressure plate 22 is axially slidably spline-coupled to the outer periphery thereof.

As will be apparent from also referring to FIGS. 8 to 10, there are six cam grooves 27 _1, ..., 3 on the right end surface of the first cam ring 27 and the left end surface of the second cam ring 33, respectively.
3 ₁ ... Is formed, and both cam grooves 27 ₁ ... 33 ₁ ...
The balls 34 are sandwiched between them. Further, at the tip of the boss portion extending to the left from the central portion of the pressure plate 22, there are provided six projections 22 ₁ with sharp tips, and these projections 22 ₁ ... are provided with six cams of the first cam ring 27. Groove 27
₁ ... engages with each. The cam groove 2 with which the projection 22 ₁ of the pressure plate 22 engages with the first cam ring 27 side
By forming the 7 ₁ ..., even kill to contribute to the reduction of the inertia moment of the first cam ring 27.

Thus, the second cam ring 33 splined to the sleeve 15, the pressure plate 22 splined to the second cam ring 33, the balls 34 and the cam grooves 27 _1, ..., On the second cam ring 33. Three
3 ₁ ... is connected through, wherein the first cam ring 27 which is pressure plate 22 to the protrusion 22 ₁ ... and the cam grooves 27 ₁ ... via the connection, rotates integrally with the sleeve 15.

As is apparent from FIGS. 4, 6 and 7,
A protrusion 26 for connecting the pilot clutch inner disc 26 to the serration 28 of the first cam ring 27.
The number of ₁ ... Is set to be smaller than the number of grooves of the serration 28 (for example, 8 in total), and each projection 2
Grooves 26 ₂ and 26 ₂ are formed on both sides of the base of 6 ₁ . Therefore, when an excessive load is applied to the pilot clutch Pc, the projections 26 ₁ are broken from the grooves 26 ₂ and 26 ₂ so that damage to the rear differential D as a whole is minimized to prevent diff lock. Can be prevented.

Pilot clutch inner disc 26 ...
Groove 26 _2, 26 ₂ is to contribute to improved lubrication of the pilot clutch Pc by an oil retained therein, further pilot clutch inner disks 26 ... projections 26
The serration groove of the first cam ring 27 that does not engage with ₁ ...
It contributes to the improvement of the lubricity of c.

As is apparent from FIG. 4, a step portion 22 ₂ is formed at the right end portion of the inner periphery of the pressure plate 22 so as to come into contact with the right end of the second cam ring 33. When the main clutch Mc is in the initial engagement state by the biasing force of the disc spring 23, a slight gap α ₃ is formed between the second cam ring 33 and the step portion 22 ₂ .

As is apparent from FIG. 9, the projections 22 ₁ of the pressure plate 22 which rotate integrally with the second cam ring 33 are provided so as to regulate the limit of the relative rotation angle between the first cam ring 27 and the second cam ring 33. Abuttable step 2
7 ₂ and 27 ₂ are cam grooves 27 ₁ of the first cam ring 27 ...
Are formed at both ends of.

Next, the operation of the embodiment of the present invention having the above construction will be described.

When the driving force of the engine is transmitted to the differential case 1 via the driven bevel gear 6, if the loads on the left axle 7 and the right axle 8 are equal, the rotation of the differential case 1 is performed by the ringer 13, the outer planetary gear 12, ... It is transmitted to the left axle 7 through the inner planetary gear 14, the sun gear 16 and the sleeve 15, and is transmitted from the outer planetary gear 12 and the inner planetary gear 14 to the right axle 8 through the planetary gear carrier 9 and both axles 7, 8 are transmitted. Rotate at the same speed. On the other hand, when there is a difference in the loads on the left axle 7 and the right axle 8, the rotation of the differential case 1 is caused by the relative rotation of the ring gear 13 and the sun gear 16 caused by the rotation and revolution of both planetary gears 12 ,. Differentially distributed to the axle 8.

The differential between the left axle 7 and the right axle 8 should be regulated.
Energize solenoid 31 of pilot clutch Pc
And the armature 29 is attracted to the solenoid 31 and left
The pilot clutch outer disc 25 ...
The irot clutch inner disc 26 ... Contact each other
It As a result, the pilot clutch Pc is engaged and the clutch
The first cam ring 27 of the cam mechanism C
Restrained by the differential case 1. At this time, the left axle 7
Between the sleeve 15 and the differential case 1 which are line-connected
If there is a slight difference in rotation, as shown in FIG.
The ring 27 and the second cam ring 33 rotate relative to each other. That
As a result, the cam groove 27 of the first cam ring 27 ₁Pressed by ...
The ball 34 ... is the cam groove 33 of the second cam ring 33.₁…
The second cam ring 33 to the main clutch Mc.
Move to the right.

When the second cam ring 33 moves right, the second cam ring 33
The pressure plate 22 whose right end of the cam ring 33 is pressed by the step portion 22 ₂ moves to the right. As a result, the main clutch outer disc 18 and the main clutch inner disc 19 of the main clutch Mc are pressed to the right,
The stopper plate 21 contacts the C-clip 38 on the right side against the disc spring 23 so as to contact each other. Thus, the center casing 4 or the differential case 1 and the sleeve 15 or the left axle 7 are integrated to lock the planetary gear type differential device P, and the differential between the left axle 7 and the right axle 8 is restricted.

As described above, the pilot clutch P
The cam mechanism C converts a small fastening force of c into a large axial thrust force, and the thrust plate 2 uses this thrust force.
2 can be operated to generate a large engagement force in the main clutch Mc.

At this time, the main clutch Mc can be smoothly engaged by the action of the gap α ₁ formed between the stopper plate 21 and the C clip 38. Further, the gap α ₃ formed between the second cam ring 33 and the pressure plate 22 acts as a dead zone of the cam mechanism C when the first cam ring 27 and the second cam ring 33 relatively rotate due to a sudden change in wheel speed. It is possible to prevent the sudden engagement of the main clutch Mc.

When the main clutch Mc is in the initial engagement state by the biasing force of the disc spring 23, the biasing force of the disc spring 23 causes the stopper plate 21, the main clutch outer disc 18 ..., the main clutch inner disc 19 ..., the pressure plate 22, It is transmitted to the left casing 2 via the first cam ring 27 and the thrust bearing 35. As a result, a predetermined engagement force is generated in the main clutch Mc to limit the differential, and it is possible to improve the running stability when, for example, a side wind is received during high-speed straight running. When the solenoid 31 is constantly energized to generate the engaging force in the main clutch Mc in order to improve the stability against the crosswind, problems such as iron powder adsorption and temperature rise of the solenoid 31 occur, but the disc spring 23 The above problem can be avoided by generating the engaging force in the main clutch Mc. Further, the load of the disc spring 23 is received by the thrust bearing 35, so that the left casing 2
Seizure is prevented.

As shown in FIG. 9, the protrusions 22 ₁ of the pressure plate 22 urged by the disc spring 23 come into contact with the cam grooves 27 ₁ of the first cam ring 27, so that the pressure plate 22 and the first The cam ring 27, that is, the second cam ring 33 and the first cam ring 27 are urged toward the centering position (position in FIG. 9).
As a result, when the pilot clutch Pc is engaged,
Regardless of the relative rotation directions of the first cam ring 27 and the second cam ring 33, the cam mechanism C can always be operated with a constant responsiveness. Further, when the relative rotation angle of the first cam ring 27 and the second cam ring 33 tries to increase beyond the allowable value, the protrusions 22 ₁ ...
Are stepped portions 27 ₂ and 27 ₂ formed at both ends of the cam groove 27 ₁ .
It is possible to prevent the planetary gear type differential device P from being locked due to unnecessary engagement of the main clutch Mc by abutting against one of them to suppress an excessive increase in the relative rotation angle. Further, the projections 22 ₁ are located at positions that cover the outer sides of the balls 34 in the radial direction, and function to prevent the balls 34 from popping out due to centrifugal force.

The stopper plate 21 and the C ring 37
By setting the gap α ₂ formed between the disc 1 and the disc ₂ to a predetermined size, when the friction material of the main clutch outer disc 18 is worn, the urging force of the disc spring 23 is increased by the discs 1 and 2.
8 ..., 19 ... are prevented from acting on both discs 18
It is possible to prevent the metal parts of ..., 19 ... from contacting each other.

11 and 12 show another embodiment of the present invention.

[0042] This embodiment includes a plurality of projections 29 ₂ ... projecting from the outer periphery of the armature 29 is slidably engaged with the serration 24 of the intermediate casing 3, which is prevented from rotating on the armature 29 is subjected by It The outer peripheral surface of the armature 29 is inclined so that the diameter becomes smaller toward the right side, and the left end surface having the maximum diameter is in sliding contact with the tip of the serration 24. Therefore, it is possible to secure a sufficient area on the side facing the solenoid 31 to prevent the attraction force from decreasing and reduce the frictional force between the serration 24 and the armature 29.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes can be made.

For example, instead of the planetary gear type differential device P in the embodiment, a normal bevel gear type differential device can be used. Further, the present invention is not limited to the differential limiting mechanism of the embodiment, and can be applied to an appropriate connecting device that connects the driving side and the driven side of the power transmission device in a disengageable manner. Furthermore, in the embodiment, the pressure plate 22 and the second cam ring 33 are spline-coupled so that they can move relative to each other, but in the invention described in claim 1, they may be connected so that they cannot move relative to each other, or both of them may move together. You may comprise by one member.

[0045]

As described above, according to the first feature of the present invention, the pressing member and the first cam ring are urged by the urging means in the direction of abutting each other to generate the frictional force therebetween. As a result, it is possible to prevent the first cam ring from being restrained by the drag torque of the pilot clutch and to integrate the first cam ring and the pressing member. As a result, the operation of the cam means due to the drag torque of the pilot clutch can be prevented, and the engagement force of the main clutch can be stabilized.

According to the second aspect of the present invention, the second cam ring is supported by the pressing member so as to be movable relative to each other, and a gap is formed between the pressing member and the second cam ring when the pilot clutch is not engaged. By allowing the second cam ring to have a play and forming a dead zone in the cam means, it is possible to prevent sudden engagement of the main clutch.

According to the third aspect of the present invention, by urging the main clutch in the engaging direction by the urging means,
The engagement force can be exerted on the main clutch without operating the pilot clutch. As a result, for example, when the present coupling device is applied to the differential limiting mechanism of an automobile, it is possible to improve crosswind stability during high-speed traveling, and it is possible to prevent wear and deterioration of the actuator of the pilot clutch.

According to the fourth aspect of the present invention, by centering the first cam ring and the second cam ring with each other by the phase angle adjusting means, the responsiveness is uniform regardless of the relative rotation directions of both cam rings. The main clutch can be engaged.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a rear differential.

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

3 is a sectional view taken along line 3-3 of FIG.

FIG. 4 is an enlarged view of a main part of FIG.

5 is a sectional view taken along line 5-5 of FIG.

6 is a sectional view taken along line 6-6 of FIG.

7 is a sectional view taken along line 7-7 of FIG.

8 is a sectional view taken along line 8-8 of FIG.

FIG. 9 is a diagram illustrating a corresponding operation of FIG.

FIG. 10 is a partial perspective view of a cam mechanism.

FIG. 11 is a partial cross-sectional view corresponding to FIG. 4 according to the second embodiment.

12 is a sectional view taken along line 12-12 of FIG.

[Explanation of symbols]

22 Pressure Plate (Pressing Member) 22 ₁ Protrusion (Phase Angle Matching Means) 23 Disc Spring (Biasing Means) 27 First Cam Ring 27 ₁ Cam Groove (Phase Angle Matching Means) 31 Solenoid (Actuator) 33 Second Cam Ring 34 Ball ( Rotating body) C Cam mechanism (cam means) Mc Main clutch Pc Pilot clutch α ₃ Gap

Claims (4)

[Claims] 1. A pilot clutch (Pc) which is engaged by an actuator (31), a cam means (C) which is operated by an engaging force of the pilot clutch (Pc), and a pressing member which is driven and moved by the cam means (C). (2
2) and a main clutch (Mc) that is engaged by movement of the pressing member (22), and the cam means (C).
Is restrained by the pilot clutch (Pc)
The cam ring (27), the second cam ring (33) provided on the pressing member (22), and the first and second cam rings (27, 33) are interposed between the two cam rings (27, 3).
A coupling device comprising a rotating body (34) for converting relative rotation of 3) into thrust, in order to generate a frictional force between the pressing member (22) and the first cam ring (27), the pressing member (22) And a first cam ring (27) and a biasing means (23) for biasing the first cam ring (27) in a direction in which they abut each other. 2. A second cam ring (33) is provided with a pressing member (2).
2) supported so that relative movement is possible, and the pilot clutch (P
The coupling device according to claim 1, wherein a gap (α ₃ ) is formed between the pressing member (22) and the second cam ring (33) when c) is not fastened. 3. The coupling device according to claim 1, wherein the biasing means (23) biases the main clutch (Mc) in the engagement direction. 4. The phase angle adjusting means (22 ₁ , 27 ₁ ) for centering the first cam ring (27) and the second cam ring (33) with respect to each other, as claimed in any one of claims 1 to 3. The connecting device according to claim 1.