JP2006336778A - Clutch cover assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a clutch cover assembly having reduced impact during clutch engagement, solving the problem that great impact occurs because a friction connection portion is rapidly held between a pressure plate and a flywheel by the thrust of a diaphragm spring when a clutch is changed from a power cut-off condition into a power transmitted condition. <P>SOLUTION: The clutch cover assembly 8 is provided for pushing the friction connection portion 12 against the flywheel 6 of an engine and cancelling the push. It comprises the clutch cover 16, the pressure plate 17, and the diaphragm spring 18. The diaphragm spring 18 is a member which is supported by the clutch cover 16 for energizing the pressure plate 17 to the side of the friction connection portion 12. It has an annular spring portion 18a and a plurality of lever portions 18b extending from the annular spring portion 18a to the radial inside. When the front ends of the plurality of lever portions 18b are driven, the annular spring portion 18a of the diaphragm spring 18 cancels the energization of the pressure plate 17. Release load occurs when the front ends of the plurality of lever portions 18b are driven, and it is characterized in that rigidity is lower in an initial region than in the other region. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a clutch cover assembly, and more particularly, to a clutch cover assembly using a diaphragm spring.

The clutch device is disposed between a vehicle engine and a transmission, and is a device for transmitting and interrupting torque from the engine to the transmission. The clutch device has a friction coupling portion that is pressed against the friction surface of the flywheel on the engine side, and is coupled to the main drive shaft of the transmission, and the friction coupling portion of the clutch disk assembly that is attached to the flywheel. And a clutch release mechanism for applying a load to the clutch cover assembly to perform a clutch release operation. (See Patent Document 1)
JP 2004-278743 A

  In the conventional clutch disk assembly, when the clutch changes from the power cut-off state to the power transmission state, the frictional connection portion is suddenly sandwiched between the pressure plate and the flywheel by the pressing force from the diaphragm spring. A big impact occurs.

  An object of the present invention is to alleviate the impact during such clutch engagement.

  A clutch cover assembly according to a first aspect is a clutch cover assembly that presses and releases a friction member against a flywheel of an engine, and includes a clutch cover, a pressure plate, and a diaphragm spring. The clutch cover is fixed to the flywheel. The pressure plate is disposed in proximity to the friction member. The diaphragm spring is a member that is supported by the clutch cover and urges the pressure plate toward the friction member, and includes an annular elastic portion and a plurality of lever portions that extend radially inward from the annular elastic portion. In this diaphragm spring, when the tips of a plurality of lever portions are driven, the annular elastic portion releases the urging to the pressure plate, and a release that occurs when the tips of the plurality of lever portions are driven. In the load characteristics, the rigidity of the initial region is lower than that of other regions.

  In this clutch cover assembly, the rigidity of the initial region is lower than that of the other regions in the characteristics of the release load generated when the tips of the plurality of lever portions are driven. Therefore, a characteristic in which the clutch torque changes gently before the clutch is completely connected can be obtained.

  Therefore, since there is a half-clutch state (a state where the clutch is not completely connected) before the clutch is in a fully connected state, it is possible to mitigate the impact generated during clutch engagement.

  In the clutch cover assembly according to the second aspect, the initial region is 0.5 mm or more.

  In the clutch cover assembly according to a third aspect, the plurality of lever portions include at least two types of lever portions having different axial heights.

  In this clutch cover assembly, the pressure plate is biased by the annular elastic portion of the diaphragm spring during clutch engagement. Along with this energization, the clutch disk and the flywheel are frictionally engaged, and the clutch device is in a state of transmitting torque (clutch on state). When changing the clutch release assembly from the clutch disengaged state to the clutch engaged state in the clutch cover assembly that releases the clutch by pressing the lever part of the diaphragm spring against the flywheel (hereinafter referred to as “push type”) First, all the lever portions of the diaphragm spring return to the free state while maintaining the state where they are pushed by the release member. At this time, the urging force from the annular elastic portion to the pressure plate gradually increases. Eventually, when the release member moves away from the lever portion whose axial height of the diaphragm spring is low, only a part of the lever portion returns to the free state while keeping the state pressed by the release member. At this time, the urging force from the annular elastic portion to the pressure plate increases, but the change per time is more gradual than the former. That is, a region where the clutch torque changes moderately is ensured immediately before the clutch is fully engaged, and the impact during clutch engagement is alleviated.

  With the diaphragm spring of the present invention, the impact during clutch engagement can be mitigated.

(1) Overall Structure FIG. 1 shows a clutch device 1 as an embodiment of the present invention. Here, OO is the rotation axis of the clutch device 1. The clutch device 1 is a device for transmitting and interrupting torque from the crankshaft 2 on the axial engine side (left side in FIG. 1) to the main drive shaft 3 on the axial transmission side (right side in FIG. 1). The clutch device 1 mainly includes a flywheel 6, a clutch disc assembly 7, and a clutch cover assembly 8. A transmission housing (not shown) is disposed on the engine side of the clutch device 1.

  The flywheel 6 is a disk-shaped member, and an annular and flat friction surface 6a facing the axial transmission side is formed on the outer peripheral portion.

  The clutch disk assembly 7 includes a friction coupling portion 12 including a friction facing disposed on the outer peripheral side, a damper mechanism 13 including a clutch plate, a retaining plate, a coil spring, and the like fixed to the friction coupling portion 12, and a damper. And a hub flange 14 connected to the mechanism 13. The friction coupling portion 12 is disposed corresponding to the friction surface 6 a of the flywheel 6. The inner peripheral portion of the hub flange 14 is spline-engaged with the main drive shaft 3.

  The clutch cover assembly 8 is a mechanism that is attached to the flywheel 6 and presses and releases the frictional connection portion 12 of the clutch disk assembly 7 with respect to the flywheel 6. The clutch cover assembly 8 mainly includes a clutch cover 16, a pressure plate 17, and a diaphragm spring 18. The clutch cover 16 is dish-shaped and has a large-diameter hole at its center. Further, the outer peripheral end of the clutch cover 16 is fixed to the flywheel 6 by a plurality of bolts 19. Furthermore, the clutch cover 16 is formed with an inner peripheral portion 16a that extends toward the inner peripheral side and is close to a hydraulic pressing device 9 described later. In this embodiment, the inner peripheral portion 16a is formed in a plurality of protrusions formed side by side in the circumferential direction and extending toward the inner peripheral side. A plurality of spring locking portions 16b are formed between the circumferential directions of the inner peripheral portion 16a.

  The pressure plate 17 is a member for sandwiching the friction coupling portion 12 of the clutch disk assembly 7 between the friction surface 6 a of the flywheel 6. The pressure plate 17 is disposed in the clutch cover 16. For this reason, the transmission side surface of the pressure plate 17 is covered with the clutch cover 16 on the outer peripheral side. The pressure plate 17 is an annular member and has a pressing surface 17 a that faces the friction coupling portion 12 of the clutch disk assembly 7. A plurality of arc-shaped protrusions 17b extending to the transmission side are formed on the inner peripheral side of the transmission side surface (the surface opposite to the pressing surface 17a) of the pressure plate.

  The pressure plate 17 is connected to the clutch cover 16 by the strap plate 20 so as not to rotate relative to the clutch cover 16 at three locations in the circumferential direction and to be movable within a predetermined range in the axial direction. Further, the strap plate 20 urges the pressure plate 17 toward the axial transmission side when the clutch is engaged.

  The diaphragm spring 18 is a member that releases the biasing force by biasing the pressure plate 17 toward the flywheel 6 and operating the lever portion. The diaphragm spring 18 includes an annular spring portion 18a and a plurality of lever portions 18b extending from the inner periphery to the center side. As shown in FIG. 2, the plurality of lever portions 18b are arranged at intervals of about 120 ° of the lever portion 18b, and as shown in FIG. 4, the inner peripheral side tip is a shaft compared to the other second lever portion 18f. There are three first lever portions 18e whose directional height is about 2,7 mm higher. A slit is formed between the circumferential directions of the plurality of lever portions 18b. The spring portion 18 a is compressed in the axial direction between the clutch cover 16 and the pressure plate 17, and always applies a pressing load to the pressure plate 17. More specifically, the axial engine side surface of the outer peripheral edge of the spring portion 18 a is in contact with the protruding portion 17 b of the pressure plate 17, and the axial transmission side surface of the inner peripheral edge is supported by the clutch cover 16. A release bearing 23 for operating the lever portion 18b to disconnect and connect the clutch is disposed at the tip of the first lever portion 18e.

  The spring engaging portion 16b of the clutch cover 16 extends through the hole of the diaphragm spring 18 and supports the inner peripheral edge of the spring portion 18a from both sides in the axial direction via two wire rings.

  The hydraulic pressing device 9 is arranged on the outer peripheral side of the main drive shaft 3 and on the axial transmission side of the inner peripheral edge of the driven portion 17 b of the pressure plate 17. The hydraulic pressing device 9 is mainly composed of a hydraulic cylinder 51.

  The hydraulic cylinder 51 is mainly composed of an annular housing 52 and an annular piston 53. The annular housing 52 is disposed so as to be movable in the axial direction with respect to the transmission housing, the main drive shaft 3 and the like, and is disposed concentrically with the rotation axis OO of the clutch device 1.

  The annular piston 53 extends in a cylindrical shape long in the axial direction, and is disposed in the annular space, but the end on the axial direction engine side protrudes from the annular space. The annular piston 53 can move in the axial direction not only with respect to the transmission housing and the main drive shaft 3 but also with respect to the annular housing 52. A release bearing 23 is attached to the axial transmission side end of the annular piston 53. The release bearing 23 is a ball bearing having a thrust capacity, and includes an inner race 64, an outer race 65, and a plurality of rolling elements 66 disposed between the two. The release bearing 23 is disposed so as to be able to press the lever portion 18b of the diaphragm spring 18. For this reason, the annular piston 53 can apply a load on the axial direction engine side to the diaphragm spring 18 without being affected by the rotation from the diaphragm spring 18.

(2) Action / Effect Next, the operation will be described.

i) Operation when the clutch is disengaged from the clutch connected state When the clutch is connected, no pressure is applied to the lever portion 18b of the diaphragm spring 18 from the release bearing 23, and the pressure plate is applied by the urging force of the spring portion 18a. 17 is urged to the flywheel 6 side, and the friction coupling portion 12 and the flywheel 6 are frictionally engaged. When the clutch is disengaged from this state, the release bearing 23 is pressed by the hydraulic pressing device 9 and the release bearing 23 moves to the flywheel 6 side. Along with the movement of the release bearing 23, first, a pressing force is applied from the release bearing 23 to the first lever portion 18 e of the diaphragm spring 18. When the first lever portion 18e is pressed, the posture of the first lever portion 18e changes, and the urging force of the spring portion 18a is partially released corresponding to the first lever portion 18e. Thereafter, when the release bearing 23 is further moved to the flywheel 6 side by about 2 to 7 mm, all the lever portions 18b are pressed by the release bearing 23 accordingly. When all the lever portions 18b are pressed, the urging force to the pressure plate 17 by the spring portion 18a is released.

ii) Operation when the clutch is engaged from the clutch disengaged state In the clutch disengaged state, the release bearing 23 presses all the lever portions 18b, and the urging force to the pressure plate 17 by the spring portion 18a of the diaphragm spring 18 is released. Has been. In order to connect the clutch from such a clutch disengaged state, it is necessary to move the release bearing 23 to the transmission side to release the pressing force to the lever portion 18b. When the release bearing 23 moves to the transmission side, first, the release bearing 23 is separated from the second lever portion 18f of the lever portion 18b, and the pressing force to the second lever portion 18f of the release bearing 23 is released. Accordingly, the spring portion 18a corresponding to the second lever portion 18f biases the pressure plate 17 toward the flywheel 6 side. Thereafter, the release bearing 23 is further moved to the transmission side by about 2 to 7 mm, so that the pressing force of all the lever portions 18b is released. Along with this, the spring portion 18a further biases the pressure plate 17 toward the flywheel 6 and the clutch is completely connected.

iii) Effect In this case, as shown in Table 1, there is a portion where the pressing load of the spring portion against the pressure plate 17 with respect to the release stroke of the release bearing 23 changes more smoothly than when the conventional diaphragm spring 18 is used. To do. Therefore, the portion where the pressing load of the spring portion 18a against the pressure plate 17 changes smoothly with respect to the release stroke can be regarded as a half-clutch state (a state where the clutch is not completely connected). Since it is in a completely connected state through a state that can be regarded as a half-clutch state (a state in which the clutch is not completely connected), the impact during clutch engagement is reduced.

(3) Other Embodiments The present invention uses a clutch device having a push type structure (the clutch is disengaged by pushing the release bearing 23 toward the flywheel side), but a pull type (pulling the release bearing toward the transmission side). The clutch device may have a structure in which the clutch is disengaged.

The longitudinal cross-sectional view of the clutch apparatus in 1 embodiment of this invention. The top view of a diaphragm spring. A graph showing release characteristics and engagement characteristics. FIG. 3 is a cross-sectional view taken along line AO-B in FIG. 2.

Explanation of symbols

1 Clutch device 6 Flywheel 12 Friction connecting part 16 Clutch cover 17 Pressure plate 18 Diaphragm spring 23 Release bearing

Claims (3)

A clutch cover assembly that presses and releases a friction member against a flywheel of an engine,
A clutch cover fixed to the flywheel;
A pressure plate disposed in proximity to the friction member;
A diaphragm spring supported by the clutch cover and biasing the pressure plate toward the friction member;
The diaphragm spring has an annular elastic portion and a plurality of lever portions extending radially inward from the annular elastic portion,
When the tip ends of the plurality of lever portions are driven in the axial direction, the annular elastic portion is configured to release the bias to the pressure plate,
In the characteristics of the release load generated when the tips of the plurality of lever portions are driven, the rigidity of the initial region is lower than the other regions.
Clutch cover assembly.   The clutch cover assembly according to claim 1, wherein the initial region is 0.5 mm or more.   The clutch cover assembly according to claim 1 or 2, wherein the plurality of lever portions include at least two types of lever portions having different axial heights.

Images