Patent Application
20120006645
The present invention relates to a clutch cover assembly, particularly a clutch cover assembly contrived to press a friction member of a clutch disk assembly against a flywheel of an engine and to release the friction member from the flywheel.
A clutch cover assembly is typically attached to a flywheel of an engine and used to transmit a drive force from the engine toward a transmission. Such a clutch cover assembly comprises chiefly a clutch cover fixed to the flywheel, a pressure plate that can push a friction member of a clutch disk assembly against the flywheel, and a diaphragm spring for pressing the pressure plate toward the flywheel. The diaphragm spring comprises an annular elastic section and a plurality of lever sections that extend radially inward from an internal edge of the annular elastic section. In addition to the function of pressing the pressure plate, the diaphragm spring also has a lever function for releasing the pressure applied to the pressure plate (e.g., see Patent Document 1).
[Citation List]
[Patent Literature]
[Patent Literature 1] Japanese Laid-open Patent Publication No. 3-22131
In a conventional clutch cover assembly, the clutch cover has an annular clutch cover body and a plurality of support sections that are provided on an inner circumferential portion of the clutch cover body and serve to support the diaphragm spring such that the diaphragm spring can undergo elastic deformation. The support sections comprise plate-like protrusions that protrude radially inward from the clutch cover body and have been bent inward. For example, the diaphragm spring and two wire rings functioning as a fulcrum when the diaphragm spring undergoes elastic deformation are sandwiched in-between the clutch cover body and the support sections. With this arrangement, the attitude of the diaphragm spring can be changed about a fulcrum located near where the diaphragm spring contacts the wire rings.
Since the support sections are formed by bending portions of the clutch cover, the structure can be simplified and the manufacturing cost can be reduced.
However, since the support sections protrude from the clutch cover body toward the flywheel, there is a possibility that the support sections will interfere with other parts in some cases.
Meanwhile, if a large space is provided in a region surrounding the support sections in order to prevent the support sections from interfering with other parts, then the clutch cover assembly will tend to be larger in size.
An object of the present invention is to provide a clutch cover assembly that can achieve a reduced manufacturing cost while also preventing the size from becoming large.
A clutch cover assembly according to the present invention is an apparatus for pressing a friction member of a clutch disk assembly against a flywheel of an engine and for releasing the friction member from the flywheel. This clutch cover assembly comprises a clutch cover, a pressure plate, and a diaphragm spring. The clutch cover is fixed to the flywheel. The pressure plate is arranged such that it can rotate as an integral unit with the clutch cover and move in an axial direction with respect to the clutch cover and contrived such that it can press the friction member against the flywheel. The diaphragm spring is supported on the clutch cover and serves to apply a force against the pressure plate toward the flywheel. The clutch cover has an annular clutch cover body that is fixed to the flywheel and a plurality of support sections that are provided on an inner circumferential portion of the clutch cover body and serve to support the diaphragm spring such that the diaphragm spring can undergo elastic deformation. The support sections are configured such that a tip end of each of the support sections tapers gradually to a smaller dimension in a circumferential direction.
With this clutch cover assembly, the size can be prevented from becoming large because the circumferential dimension of the tip ends of the support sections tapers gradually to a smaller dimension such that the space occupied by the support sections can be reduced. Additionally, since the support members are plate-like, the structure can be simplified and the manufacturing cost can be reduced.
<Overall Structure of Clutch Cover Assembly>
The clutch cover assembly 1 shown in
A line O-O shown in
As shown in
As shown in
(1) Clutch Cover Body
As shown in
(2) Support Section
The support sections 24 are arranged on an inner circumferential portion of the clutch cover body 25 (inner circumferential portion of the annular section 23) and serve to support the diaphragm spring 4 on the clutch cover assembly 25 such that the diaphragm spring 4 can undergo elastic deformation. More specifically, as shown in
The first portion 24a protrudes axially toward the engine from an inner circumferential edge of the annular section 23 and is inserted through a hole 4c (explained later) of the diaphragm spring 4.
The second portion 24b is curved from an end portion of the first portion 24a as shown in
The second portion 24b curves toward a radially outward direction and touches against one wire ring 6. Another wire ring 6 touches against the annular section 23. The two wire rings 6 and the diaphragm spring 4 are sandwiched between the annular section 23 and the second portion 24b.
The third portion 24c is a portion that protrudes in a radially outward direction from an end portion of the second portion 24b and has a portion with a smaller width than the second portion 24b. More specifically, as shown in
Also, an end surface 24e joins the diagonal surfaces 24d together at the tip end of the third portion 24c. The end surface 24e is perpendicular to the centerline C. Due to the diagonal surfaces 24d, a width of a tip end portion of the support section 24 gradually tapers to a smaller width as one moves in a radially outward direction along the support section 24.
The pressure plate 3 is an annular member having a pressing surface 3a formed on a side that faces toward the flywheel 51. The friction member 53 of the clutch disk assembly is arranged between the pressing surface 3a and the flywheel 51. A generally annular protrusion 3b that protrudes in an axial direction is provided on the opposite side of the pressure plate 3 as the side where the pressing surface 3a is located. The pressure plate 3 is connected to the clutch cover 2 with a plurality of strap plates 7 (
As shown in
The diaphragm spring 4 is a circular disk-shaped member that is arranged between the pressure plate 3 and the clutch cover 2 and supported by the clutch cover 2 such that it can undergo elastic deformation. More specifically, the diaphragm spring 4 has an annular elastic section 4a and a plurality of lever sections 4b that extend radially inward from an inner circumferential portion of the annular elastic section 4a. The annular elastic section 4a touches against the protrusion 3b of the pressure palate 3 when the clutch is engaged. A plurality of slits are formed between the lever sections 4b and a plurality of holes 4c are formed at radially outward ends of the slits.
The first portions 24a of the support sections 24 are inserted through the holes 4c. The two wire rings 6 are arranged both axially opposite sides of the diaphragm spring 4 and the two wire rings 6 and the diaphragm spring 4 are sandwiched between the support sections 24 and the annular section 23. More specifically, the wire rings 6 and an inner circumferential portion of the annular elastic section 4a are sandwiched between the second portions 24b of the support sections 24 and an inner circumferential portion of the second portion 24b. The second portion 24b and an inner circumferential portion of the annular section 23 each contact one of the wire rings 6.
Also, a push-type release device (not shown) is arranged contacting the tip ends of the lever sections 4b of the diaphragm spring 4. To release the clutch, the release device pushes the end portions of the lever sections 4b of the release device toward the engine and releases a pushing force the diaphragm spring 4 is exerting against the pressure plate 3.
When the release device is not exerting a load against the tip ends of the lever sections 4b of the diaphragm spring 4, the pressure plate 3 is pushed toward the engine relative to the clutch cover 2 by the annular elastic section 4a. As a result, the friction member 53 of the clutch disk assembly is pressed against the flywheel 51 and a torque is transmitted to the clutch disk assembly (clutch in connected state).
When the release device pushes the tip ends of the lever sections 4b of the diaphragm spring 4 toward the engine, an outer circumferential portion of the annular elastic section 4a of the diaphragm spring 4 is lifted in an axial direction toward the transmission about a fulcrum located at a contacting portion between the wire rings 6 and the diaphragm spring 4. As a result, the annular elastic section 4a no longer pushes the pressure plate 3 and, the pressure plate 3 separates from the friction member 53 due to the elastic forces of the strap plates 7, and finally the friction member 53 separates from the flywheel 51 (clutch in released state).
During the release operation, an attitude of the diaphragm spring 4 with respect to the clutch cover 2 changes about a fulcrum located at a portion where the diaphragm spring 4 contacts the wire rings 6. Consequently, a portion of the clutch cover 2 that contacts the wire rings 6 is pressed by the wire rings 6 and could easily become worn.
However, with this clutch cover assembly 1, since the width of the second portions 24b of the support sections 24 are set to be comparatively wide, the surface pressure at the portions where the wire rings 6 contact the second portions 24b can be held comparatively low and wear of the clutch cover 2 can be suppressed.
Since the width of the tip ends of the support sections 24 (third portions 24c) tapers gradually to a smaller width, the amount of space occupied by the support sections 24 can be reduced and the clutch cover assembly can be prevented from becoming large in size. Furthermore, since the support sections 24 are plate-like, the structure can be simplified and the manufacturing cost can be reduced.
Since the third portions 24c of the support section 24 are arranged inside the recessed sections 3d of the pressure plate 3, the pressure plate 3 can be arranged closer to the clutch cover 2 in an axial direction and the axial dimension of the entire clutch cover assembly 1 can be shortened.
Since the third portions 24c have diagonal surfaces 24d, the size of the tip ends of the support sections 24 can be held small even though the width of the second portions 24b is large. Thus, the support sections 24 can be configured to fit inside the recessed sections 3d of the pressure plate 3 even if the width of the support sections 24 is set to be large. As a result, the same pressure plate 3 can be used with clutch covers 2 having different design specifications and productivity can be increased.
The present invention is not limited to the embodiment explained above and variations can be made without departing from the scope of the invention. Parts that have substantially the same function as the parts of the previously explained embodiment are assigned the same reference numerals as in the previously explained embodiment and detailed explanations thereof are omitted.
Although the previously explained third portion 24c has a pair of diagonal surfaces 24d, it is acceptable to configure a support section 124 such that the third section 124c has one diagonal surface 124d instead of a pair of diagonal surfaces 24d, as shown in
The a clutch cover assembly according to the present invention is applicable to a power transmitting apparatus for a vehicle because it enables a manufacturing cost to be suppressed while keeping the size of the clutch cover assembly in check.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-091444 | Apr 2009 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2010/054290 | 3/15/2010 | WO | 00 | 9/16/2011 |
