JPH0585771B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a clutch release mechanism for a vehicle, and more particularly to a so-called release fork retrofit type vehicle clutch release mechanism in which a release fork can be assembled after a clutch and transmission are fixed to a cylinder block of an engine. This is related to.

[Conventional technology]

A normal vehicle clutch release mechanism supplies the hydraulic pressure generated in the master cylinder to the release cylinder by operating the clutch pedal, and uses the release fork as a fulcrum member (such as a fork ball).
The clutch is rotated using the release fork as a fulcrum, and the release hub carrying the release bearing is slid in the axial direction by the release fork to release the clutch. The release fork and the release hub are connected by a clip to restrain each other from moving in the axial and rotational directions (for example, as disclosed in Japanese Utility Model Application No. 50-114547 and Japanese Utility Model Application No. 57-127924). ). Generally, the middle fulcrum type release fork is
It is preassembled in a state in which approximately the middle portion thereof is rotatably supported on a spherical surface by a fulcrum member (such as a fork ball) provided at a predetermined location within the clutch housing. For this reason, the release fork must be assembled before the clutch housing is fixed to the cylinder block of the engine, and it is extremely difficult to attach and remove the release fork with the clutch housing fixed to the cylinder block of the engine. Therefore, it was almost impossible to replace the release fork without removing the clutch housing from the cylinder block. Therefore, the present applicant fixed the fulcrum pin across the bases of the bifurcated arms of the release fork, while at the same time changing the fork support that rotatably supports the fulcrum pin to the clutch housing. The release fork is fixed in advance to the inner wall of the clutch housing, and is inserted into the release hub carrying the clutch release bearing from the fork insertion hole opened in a part of the lower part of the clutch housing in a direction perpendicular to the axis of the release hub. A clutch release mechanism was previously proposed in which the fulcrum pin of the fork support is engaged with and supported by the hook portion of the fork support (Japanese Patent Application Laid-open No. 157519/1983). With this clutch release mechanism, the middle fulcrum type release fork can be easily attached and detached while the clutch housing remains fixed to the cylinder block, so it is easy to assemble the release fork during the manufacturing process. In particular, an excellent effect was obtained in that the subsequent work of replacing the release fork was extremely simple. However, in the vehicle clutch release mechanism of the release fork retrofit type configured as described above, the outer circumference of the release hub is cylindrical from the viewpoint of ease of assembling the release fork, so that the rotation between the release fork and the release hub is prevented. Have difficulty. Therefore, as the clutch release bearing rotates, the release hub also rotates, and this rotation causes various sliding noises (between the release fork and the release hub, between the release hub and the bearing retainer), and when the wear of various parts increases. I had a problem. To solve this problem, it has been proposed to form two surfaces (width across flats) parallel to each other on the outer periphery of the release hub to add a means for preventing rotation with the release fork (Japanese Patent Application Laid-Open No. 56-97632). Publication No.). If the release hub is simply formed with a width across flats, the release fork cannot be assembled unless the width across flats matches the direction in which the release fork is assembled, and the assemblability of the release fork is significantly deteriorated. In this case, the outer periphery of the release hub is made into a polygonal shape to provide many parallel two sides to increase the chances of engagement between the release fork and the release hub. The arm pushes the release hub around to match the width across flats with the direction in which the release fork is to be assembled, thereby reducing ease of assembly.

[Problem to be solved by the invention]

However, in the technique disclosed in Japanese Unexamined Patent Publication No. 56-97632, since the inner sides of the two arms are formed parallel to each other, the following problems occur. Firstly, before the short arm reaches the release hub, the long arm must completely align the width across flats of the release hub with the arm.
This is a problem in that the longer arm needs to protrude considerably longer, which increases the size of the release fork, resulting in a large increase in weight, which is undesirable for a moving part. To solve this problem, it is possible to reduce the width across flats to reduce the protrusion of the longer arm, but this would make the engagement between the release hub and release fork unstable. , it is not a fundamental solution. Another problem is that even if the release fork is allowed to increase in size and one arm is formed long enough, the release hub cannot be rotated sufficiently, making it difficult to engage the release fork and the release hub. This is a problem that may arise.
In other words, if the tip of the longer arm slips along the outer contour of the release hub, the rotation of the release hub will stop midway, and the width across flats of the release hub will not align with the arm, and the shorter end will The problem is that the release hub becomes unable to rotate when the arm comes into contact with the release hub, and the release hub cannot be inserted any further. This can occur because the release fork is not completely locked to the support shaft or hook during the insertion of the release fork. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to improve the ease of assembling the release fork in a clutch release mechanism for a vehicle of the release fork retrofit type that enables rotation prevention between the release fork and the release hub.

[Means to solve the problem]

Therefore, the present invention employs the following configuration as a means for solving the above-mentioned problems. That is, in a vehicle clutch release mechanism of a release fork retrofitting type in which a release fork having a bifurcated arm can be assembled from a direction perpendicular to the axis of the release hub on which the clutch release bearing is supported, the release fork in the release hub 40 is provided. A plurality of sets of two parallel surfaces 43 are provided on the outer periphery of the engaging portion with the fork, and a corner portion 43a is formed by the intersection of the two adjacent parallel surfaces, and the bifurcated portion that engages with the release hub One of the arm distal ends 510 is formed longer than the other 511, and the long distal end has an interval between the bifurcated arms that is closer to the distal end than the part that locks the outer periphery of the release hub, and toward the distal end. It is characterized in that a tapered chamfer 512 is formed to widen the area.

[Effect]

According to the above means, one of the bifurcated arm tips 510 of the release fork is formed longer than the other 511, so that when the release fork is pushed in, the longer arm tip comes into contact with the release hub first. If the release fork is further pushed in from this state, the release hub rotates as the release fork is inserted since rotation is not restricted. Therefore, there is a high possibility that the two parallel surfaces of the release hub will be aligned in the release fork insertion direction before the shorter arm tip comes into contact with the outer periphery of the release hub. Even if the two parallel surfaces of the release hub and the direction of insertion of the release fork are insufficiently aligned when the short end of the arm comes into contact with the outer periphery of the release hub, the long end of the arm will still be attached to the release hub. A tapered chamfer 512 is formed on the distal end side of the part that locks the outer periphery, which widens the gap between the bifurcated arms toward the distal end, so rotation of the release hub is allowed to some extent, and both arms are in contact with each other. If you push the arm further when they make contact, the release hub will rotate along the tapered surface in a direction where the two parallel surfaces are aligned with the release fork insertion direction while being sandwiched between the two arms, and the arm will be completely inserted. . Even in the rare case that the release hub is difficult to rotate, simply by slightly shifting the insertion direction of the release fork, the contact angle between the tapered chamfer and the release hub changes, making it possible to rotate the release hub. When the arm is completely inserted, two parallel surfaces (or a corner formed at the intersection of the two parallel surfaces) on the outer periphery of the release hub are engaged with the arm, and rotation is reliably prevented.

【Example】

Hereinafter, prior to describing the embodiments of the present invention, the clutch release mechanism that is the premise will be explained in detail. [Prerequisite clutch release mechanism] Figures 1 to 8 are diagrams for explaining the vehicle clutch release mechanism related to the present invention. Figure 1 is an overall view of the clutch seen from the rear of the vehicle, The figure is a vertical sectional view of the clutch shown in Figure 1 taken along a plane including the release fork, Figure 3 is an enlarged external perspective view of the fork support and its attached components, and Figure 4 is a view from the rear of the vehicle. FIG. 5 is a side view of the conventional release fork shown in FIG. 4, FIG. 6 is an enlarged vertical sectional view of the release hub, and FIG. 7 is the same as FIG. 6. FIG. 8 is a schematic view of the conventional release fork assembly process seen from the front of the vehicle, showing the process of assembling the release fork to the release hub. First, the overall structure of a vehicle clutch will be explained using FIGS. 1 and 2. For ease of understanding, FIG. 1 omits the input shaft and front bearing retainer of the transmission, and shows a portion in cross section. Reference numeral 10 indicates a cylinder block of a so-called vertical engine in which the axis of a crankshaft 12 is arranged in the longitudinal direction of the vehicle, and 20 indicates a cylinder block 10.
2 shows the clutch housing secured by bolts 21. This clutch housing 20
Therein, a flywheel 30 is secured to the end of the engine crankshaft 12 by bolts 11 in a known manner and is adapted to rotate therewith. A clutch cover 32 is fixed to the flywheel 30 with bolts 31, as shown in FIG. A diaphragm spring 33 and a pressure plate 3 are located inside the clutch cover 32.
4 is assembled together with other components as an assembly. On the other hand, the input shaft 13 of the transmission (not shown) has its tip aligned with the pilot bearing 1 with respect to the center of the flywheel 30.
4, and is disposed at the rotation axis of the clutch while being relatively rotatably supported by the clutch. A hub 36 of a clutch disk 35 is supported by a spline 15 formed on the outer periphery of the input shaft 13 so as to be slidable in the axial direction and not relatively rotatable. The facing 37 of the clutch disk 35 is strongly held between the flywheel 30 and the pressure plate 34 based on the mounting load of the clutch cover 32, that is, the set spring force of the diaphragm spring 33. As a result, torque can be transmitted between the flywheel 30 (including the clutch cover 32 and pressure plate 34 which are integrally connected thereto) and the input shaft 13 via the clutch disk 35. The clutch cover 32 and the pressure plate 34 are connected to each other so as to be able to transmit torque and to be relatively displaceable in the axial direction using a well-known chordal strap (not shown). Further, a rivet 38 shown in FIG. 2 is attached between the clutch cover 32 and the pressure plate 34. This rivet 38 is attached to the front of the pressure plate 34 in the axial direction (left side in the figure) by the diaphragm spring 33 when the bolt 31 is removed.
This is to restrict the movement of the clutch cover 32 and the pressure plate 34 within a predetermined range, and to prevent plastic deformation of the chordal strap that connects the clutch cover 32 and the pressure plate 34. Further, a release hub 40 carrying a pull-type release bearing 41 slides in the axial direction on the outer periphery of the cylindrical portion of the front bearing retainer 16, which is arranged concentrically with the input shaft 13 and fixed to the front surface of the transmission case. possible to assemble. The outer race of the release bearing 41 is secured to the lever tip (periphery of the center hole) of the diaphragm spring 33 by a snap ring via a resin washer plate and a wave washer. A working hole 22 is formed in the clutch housing 20 to allow working from the outside.
The position of this working hole 22 is set at the center of the clutch housing (the center of the clutch) from the viewpoint of workability and the space between it and the floor tunnel part when mounted on the vehicle.
It is more advantageous to move downward. In addition, the working holes 22 must be large enough to allow at least one hand to be inserted, and at least two must be provided so that the work can be done with both hands.Furthermore, the mounting bolts 31 inside the clutch housing must be removable. In this embodiment, a pair of left and right working holes 22 are formed below the clutch housing 20. A pair of working holes 22
are respectively closed by covers 24 fixed by bolts 23 as shown in FIG. This cover 24 prevents muddy water etc. from entering the inside of the clutch housing, and also prevents the clutch cover 3 from entering.
As the second gear rotates, low-temperature outside air is sucked in through the intake port formed on one cover, and high-temperature air is exhausted from the exhaust port formed on the other cover to ventilate the inside of the clutch housing and cool the clutch. I'm starting to do that. Further, a fork support 25 having an external appearance as shown in FIG. 3 is fixed to the inner wall of the clutch housing 20 by two bolts 26. This fork support 25 includes a hook portion 27 whose open portion is located in a direction facing the one working hole 22 (diagonally downward). Further, both bolts 26 serve to tighten the fork support 25 and at the same time to fix a fork spring 28 formed using a leaf spring material as shown in FIG. 3. Conventional release fork 50 with middle fulcrum type
As is clear from FIGS. 4 and 5, it is provided with a bifurcated arm 51 at one end, and an arcuate surface 52 that comes into contact with the flange 42 formed on the release hub 40 is formed at the tip thereof. There is.
Moreover, the opposing surfaces between both arms 51 have a distance W ₁
The engagement surfaces (hereinafter referred to as fork surfaces) 53 are parallel to each other and engage with the release hub 40 . Further, at the end of the release fork 50 opposite to the bifurcated arm 51, a hemispherical groove 54 is formed to receive a push rod end of a release cylinder, which will be described later. Further, a fulcrum pin 55 is passed through the bases of both arms 51 between them, and a disc spring 56 is inserted between the two arms 51.
It is fixed without play by an E ring 57 via the E ring 57. Furthermore, a partially cylindrical bulge 58 centered on the axis of the fulcrum pin 55 is formed at the base of both arms 51 that support the fulcrum pin 55 . The fulcrum pin 55 is rotatably supported by the hook portion 27 of the fork support 25, as shown in FIG. In this state, the arm 51 is assembled to the release hub 40 so as to sandwich the outer periphery of the release hub 40 from both sides.
In this state, the bulges 58 formed at the bases of both arms 51 are received by the fork springs 28, and the release fork 50 is biased to the left in FIG. As a result, the fulcrum pin 55 of the release fork 50 is pressed against the hook portion 27 of the fork support 25, and the arcuate surfaces 52 of both arms 51 are pressed against the flange 42 of the release hub. In this assembled state,
The release fork 50 is stable and will not fall off the fork support 25. Furthermore, a release cylinder 60 of a hydraulic clutch release system is fixed to a part of the clutch housing 20 with bolts 61. And the push rod 6 of the release cylinder 60
2 is in contact with the groove 54 of the release fork 50 inside the clutch housing 20, and the other end is in contact with the piston 63. Now, as shown in FIGS. 6 and 7, the release hub 40 is made of a single integrally molded member. The outer peripheral shape of the release fork engaging portion of the release hub 40 is particularly octagonal with two parallel surfaces (hereinafter referred to as hub surfaces) 43, as shown in FIG. The interval W ₂ between the hub surfaces 43 is set to be slightly smaller than the aforementioned interval W ₁ between the fork surfaces 53 (for example, so that a gap of about 0.5 mm exists). Furthermore, the corner where the hub surfaces intersect is a partial cylindrical surface 43a that is concentric with the central axis O of the release hub 40 (clutch center).
It is formed as. Note that 44 and 45 shown in the figure are an annular projection for positioning the release bearing 41 in the axial direction and an annular groove for attaching a snap spring. In the vehicle clutch release mechanism configured as described above, when the clutch pedal (not shown) is depressed, hydraulic pressure is supplied from the master cylinder (not shown) to the inside of the release cylinder 60.
The piston 63 moves to the left in FIG. Then, the release fork 50 rotates clockwise in FIG. 2 about the fulcrum pin 55 with respect to the fork support 25 via the push rod 62. Accordingly, the release bearing 41 is slid along the front bearing retainer 16 together with the release hub 40 toward the right in FIG. 2. In this way, the diaphragm spring 33 is displaced in the same direction, and the pressure plate 34 is also displaced in the same direction due to the spring force of the chordal strap. As a result, the clamping force on the clutch disk 35 based on the spring force of the diaphragm spring 33 is released, and the engine crankshaft 1
Torque transmission between the flywheel 2 (flywheel 30) and the input shaft 13 is cut off, and the clutch becomes in a released state. Next, a procedure for assembling the conventional release fork 50 described above will be explained. First, the clutch housing 20 is already fixed to the cylinder block 10 of the engine with bolts 21, and the clutch housing 20 is
0, the aforementioned clutch components and transmission input shaft 13 are incorporated. It is assumed that the cover 24 is not yet attached to the working hole 22 formed in a part of the clutch housing 20 shown in FIG. Next, insert the release fork 50 into the clutch housing 20 through the working hole 22 so that the bifurcated arm 51 of the release fork 50 comes first, and then insert the release fork 50 into the release hub 40.
Insert in the direction perpendicular to the axis O of the Then, the fulcrum pin 55 of the release fork is engaged with the hook portion 27 of the fork support, and the distal end of the bifurcated arm 51 of the release fork is engaged with the release hub 40. At this time, the outer circumferential shape of the release fork engaging portion of the release hub 40 is adjusted to two parallel surfaces (hub surfaces) 4
Since the fork surface 53 of the release fork and one of the hub surfaces 43 of the release hub are formed in a polygonal shape having a polygonal shape of 3, there is an increased chance that the fork surface 53 of the release fork and any hub surface 43 of the release hub are in a substantially parallel position. Therefore, as shown in FIG. 8a, it is possible to easily engage the arm tip of the release fork 50 with any hub surface 43 of the release hub 40. Further, since the corner portion of the hub surface 43 is formed by the partial cylindrical surface 43a, the arm end portion of the release fork 50 can be smoothly engaged with the release hub 40. At this time, the bulging portions 58 of both arms are received by the fork springs 28 as described above, and the release fork 50 is maintained in a stable assembled state without coming off from the fork support 25. Note that the rotational direction position of the release hub 20 is not restricted, and the release hub 20 is at an arbitrary rotational direction position. If the release hub 40 is located in the state shown in FIG. 8b, the release fork 50 cannot be smoothly engaged with the hub surface 43 of the release hub. Therefore, in this case, insert your hand through the working hole 22, shift the release hub 40 slightly in the rotational direction, and engage the release fork 50. After that, the release cylinder 60 is fixed to the clutch housing 20 with bolts 61,
The tip of the push rod 62 is brought into contact with the groove 54 of the release fork. This completes the assembly of the release fork 50 and the release cylinder 60, and finally the cover 24 is attached to the working hole 22 of the clutch housing with the bolt 23. Further, when the release fork 50 is to be removed for purposes such as replacement, it can be easily done by reversing the above procedure while the clutch housing 20 remains fixed to the cylinder block 10. The fork surface 53 at the arm tip of the release fork and the hub surface 4 of the release hub.
3, the release hub 40 can be reliably prevented from rotating. Therefore, it is possible to prevent various sliding noises caused by the rotation of the release hub 40 between the release hub 40 and the release fork 50, between the release hub 40 and the bearing retainer 16, and the like. Furthermore, wear of each part can be reduced at the same time. 9 and 10 show modified examples of the release hub. FIG. 9 is a longitudinal sectional view (corresponding to FIG. 6), and FIG. 10 is a view seen from the rear of the vehicle. This modification is an example applied to a so-called normal push-type clutch release mechanism in which the clutch is released by pressing the release bearing toward the flywheel against the diaphragm spring. The release hub 400 is composed of two members: a main body 460 that carries a release bearing and has a flange 420 against which the release fork 50 comes into contact, and a separate polygonal member 470 that has an octagonal outer peripheral shape and a hub surface 430. has been done. A polygonal member 470 is integrally fixed to the small diameter cylindrical surface of the main body portion 460 by means such as press fitting. In addition, the imaginary line is release fork 5
It shows 0. According to this modification, since the release hub 400 is constructed from two members, it is possible to make the outer peripheral shape of the release fork contact portion polygonal without significantly changing the shape of the existing release hub. Therefore, manufacturing is extremely easy and costs can be reduced. 11 and 12 show other modifications of the release hub. FIG. 11 is a longitudinal sectional view, and FIG. 12 is a view seen from the rear of the vehicle. Note that in FIGS. 11 and 12, parts corresponding to those in FIGS. 9 and 10 are designated by the same reference numerals as in FIGS. 9 and 10. In this modification, the separate polygonal member 471 corresponding to the second embodiment is made into a hexagonal shape and made of a resin material. According to this modification, since the mating member with which the release fork 50 engages is the polygonal member 471 made of resin, the coefficient of friction is low, ensuring smooth sliding of the aforementioned partial cylindrical surface 43a of the corner, etc. It is also possible to reduce the sliding noise between the two. The above is the clutch release mechanism that is the premise of the present invention, and examples in which the present invention is applied to such a clutch release mechanism will be described in detail below. [Embodiment of the present invention] Figures 13 to 17 show a clutch release mechanism for a vehicle according to an embodiment of the present invention.
The figure is an overall view of the clutch seen from the rear of the vehicle (corresponding to Figure 2 above), Figure 14 is an enlarged view of the release fork showing a partial cross section as seen from the rear of the vehicle (corresponding to Figure 4 above), Figure 15 is a side view of the release fork shown in Figure 14, Figure 16 is a schematic view from the front of the vehicle showing the process of assembling the release fork to the release hub, and Figure 17 is a side view of the release fork shown in Figure 14. FIG. 2 is a schematic view of the vehicle as seen from the rear, showing a working state in which the parts are inserted and assembled. Note that in FIGS. 13 to 18, parts corresponding to those in FIGS. 2 to 8 are designated by the same reference numerals as above. In this embodiment, the ease of assembling the release fork to the release hub is further improved by devising the shape of the release fork relative to the outer peripheral shape of the release hub. That is, as shown in FIGS. 14 and 15, one of the bifurcated arm tips 510 (left side in FIG. 14) of the release fork 500 is located above the other 511 (right side in FIG. 14) by l. It has been formed for a long time. This length difference l is preset to a length that does not cause the release hub 40 to interfere with the shorter arm tip 511 in FIG. 16b. Furthermore, the tip of the arm that engages with the hub surface 43 of the release hub has tapered chamfers 512, 513 that widen the distance between the arms toward the tip of the arm.
is formed. The release fork 500 is arranged so that the longer arm tip 510 is positioned upward, as shown in FIG. Note that the other structural members including the release hub 40 are similar in shape to the structural members shown in FIGS. 1 to 7, so detailed explanations will be omitted. When using the conventional release fork described above, the release fork cannot be easily engaged with the hub surface 43 when the hub surface 43 of the release hub is in the rotational position as shown in FIG. 8b. In contrast, in this embodiment, as shown in FIG. 16, even if the hub surface 43 of the release hub is positioned in the state shown in FIG. 8b, the release fork 500 can be assembled smoothly. That is, as shown in FIG. 16a, when the release fork 500 is inserted from the direction perpendicular to the axis O of the release hub 40, the longer arm tip 5
The chamfer 512 of No. 10 comes into contact with any hub surface 43 of the release hub first, and the release hub 40 begins to rotate around the axis O along the bearing retainer 16 in the direction of the arrow (counterclockwise in the figure). Then, the release hub is rotated until the hub surface 43 of the release hub that is in contact with the chamfer 512 becomes parallel to the fork surface 530 of the longer arm tip 510.
The release hub 40 rotates as shown in FIG. 6b.
Release hub 40 with both surfaces parallel
stops rotating. At this time, the fork surface 531 of the shorter arm tip 511 is also parallel to the hub 43. Subsequently, the fork surface 530 of the longer arm tip 510 serves as a guide, and as shown in FIG. 16c, the fork surface 530 of the longer arm tip 510 smoothly engages with the hub surface 43 of the release hub together with the other arm tip 511. In addition, the tip of the longer arm may slip along the outer periphery of the release hub, and when the rotation of the release hub 40 is insufficient, the tip of the shorter arm may slide around the hub surface 40.
3, it is possible to completely insert the arm by pushing the arm further from that state. That is, since the tapered chamfer 512 is formed on the longer arm tip 510, rotation of the release hub 40 is allowed to some extent even when the shorter arm tip is in contact with the release hub 40, and the release hub 40 , the hub surface 43 rotates along the chamfer 512 of the longer arm in a direction parallel to the fork surfaces 530, 531, and the engagement between the arm and the hub surface 43 is completed. At this time, in this embodiment, since the shorter arm is also provided with a tapered chamfer 513, the rotation of the release hub 40 becomes smoother. Furthermore, even in this embodiment, there are rare cases where the release fork 500 does not enter smoothly, but this occurs less frequently than when using the conventional release fork without the above-mentioned tapered chamfer.
Even in such a case, since the tapered chamfer is provided, the release hub 40 can be rotated simply by slightly shifting the insertion direction of the release fork 500. As described above, in this embodiment, the rotation of the release hub 40 is facilitated by the tapered chamfer, and the workability of assembling the release fork 500 is improved. At this time, since the rotation promoting means is constituted by a tapered chamfer, when the tapered surface pushes the hub surface 43 in a substantially surface contact state, a large frictional force acts, and a particularly large rotation promoting effect is produced. You can expect it. Furthermore, since the operator grasps the lower end of the release fork 500 and inserts it from the working hole 22 of the clutch housing, it is preferable from the viewpoint of workability to arrange the arm so that the longer arm tip 510 is positioned upward. . In other words, in the case of this embodiment, by applying the longer arm tip 510 to the release hub 40 by the weight of the release fork 500 and then inserting it, the arm tip can be engaged with the hub surface 43 very easily. (If the vertical direction is reversed, the release fork 500 will be engaged with the release hub 40 while being lifted). Although FIG. 17 shows the transmission case removed, the transmission case is actually fixed to the rear of the clutch housing 20, so the release fork 50
0 is not visible from the outside. Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to the above embodiments, and includes various embodiments within the scope of the claims. For example, the outer peripheral shape of the release fork engaging portion in the release hub is not limited to hexagonal or octagonal shapes, but may be any other shape as long as it is possible to prevent rotation with the release fork. Further, although it is more effective to provide the tapered chamfer on both arms, it is also possible to provide the tapered chamfer on only one arm to simplify the processing as long as the above-mentioned function is not lost.

【Effect of the invention】

As explained above, according to the present invention, the rotation of the release hub during assembly is facilitated by providing a tapered chamfer at the tip of the arm of the release fork, which reduces the frequency of turning the release hub by hand. Even in the rare case that the release hub is difficult to rotate and the release fork cannot be inserted smoothly, just by slightly shifting the insertion direction of the release fork, the tapered chamfer will help the release hub rotate. The frequency of turning the release hub by hand is reduced, and the ease of assembling a clutch release mechanism for a vehicle with a release fork retrofitted type is improved. Furthermore, the long end of the bifurcated arm allows the release hub to be rotated before it is sandwiched between the two arms.
In combination with the effect of promoting rotation of the release hub due to the tapered chamfer, it is possible to improve the ease of assembly. Moreover, since the above effects can be achieved by only slightly changing the shape of the release fork, it is extremely practical without requiring any major changes to the conventional structure.

[Brief explanation of the drawing]

1 to 8 show a clutch release mechanism for a vehicle related to the present invention. FIG. 1 is an overall view of the clutch seen from the rear of the vehicle, and FIG.
FIG. 3 is an enlarged external perspective view of the fork support and its attached components. FIG. Figure 5 is a side view of the conventional release fork shown in Figure 4, Figure 6 is an enlarged vertical sectional view of the release hub, Figure 7 is a sectional view taken along the - line in Figure 6, and Figure 8 is a view of the release hub. 9 and 10 are schematic diagrams showing the conventional release fork assembly process as seen from the front of the vehicle, and show modified examples of the release hub of the clutch release mechanism for vehicles. Fig. 10 is a view seen from the rear of the vehicle, Figs. 11 and 12 show other modifications of the release hub of the clutch release mechanism for a vehicle, Fig. 11 is a longitudinal sectional view, and Fig. 12 is a view from the rear of the vehicle. View from above, Figures 13 to 17
The figures show a clutch release mechanism for a vehicle according to an embodiment of the present invention. FIG. 13 is an overall view of the clutch seen from the rear of the vehicle, and FIG. 14 is a cross-sectional view of a portion of the clutch seen from the rear of the vehicle. An enlarged view of the release fork, Fig. 15 is a side view of the release fork shown in Fig. 14, Fig. 16 is a schematic view from the front of the vehicle showing the process of assembling the release fork to the release hub, and Fig. 17 is the clutch housing. FIG. 3 is a schematic diagram, seen from the rear of the vehicle, showing a working state in which a release fork is inserted and assembled through a working hole. Explanation of symbols, 10... Engine cylinder block, 13... Transmission input shaft, 16... Front bearing retainer, 20... Clutch housing, 22... Working hole, 25... Fork support, 30... ... flywheel, 32 ... clutch cover, 33 ... diaphragm spring, 34 ... pressure plate, 35 ... clutch disk, 40 ... release hub, 41 ... clutch release bearing, 42 ... flange, 43 ... Two parallel surfaces (hub surface), 43a...partial cylindrical surface, 50...release fork, 51...bifurcated arm, 53...engaging surface (fork surface), 55...fulcrum pin, 60...
Release cylinder, 400...Release hub, 4
20... Flange, 430... Parallel two surfaces (hub surface), 460... Main body, 470... Polygonal member,
471... Resin polygonal member, 500... Release fork, 510... Longer bifurcated arm tip, 511... Shorter bifurcated arm tip,
512,513... chamfer, 530,531...
Engagement surface (fork surface), O...Axis of release hub.

Claims (1)

[Scope of Claims] 1. In a vehicle clutch release mechanism of a release fork retrofitting type in which a release fork having a bifurcated arm can be assembled from a direction perpendicular to the axis of the release hub on which the clutch release bearing is supported, A plurality of sets of parallel two surfaces are provided on the outer circumferential shape of a portion of the release hub that engages with the release fork, and a corner portion is formed by the intersection of the two adjacent parallel surfaces, and the bifurcation that engages with the release hub. Either one of the distal ends of the bifurcated arm is formed longer than the other, and the long distal end is disposed on the distal end side of the part that locks the outer periphery of the release hub, and the distance between the bifurcated arms increases toward the distal end. A clutch release mechanism for a vehicle, characterized in that a tapered chamfer is formed to expand the clutch release mechanism.