JP2011106650A - Clutch device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a clutch device that can reduce stress caused by centrifugal force and generated in each fastening bolt fastening a flywheel and a clutch cover to each other at each outer peripheral part of the flywheel and the clutch cover. <P>SOLUTION: A clutch device 10 is configured as follows. A clutch cover 22 has each fastening part 22b formed protrudingly from the outer peripheral part of a cover body 22a to the side of a flywheel 21. The flywheel 21 and the clutch cover 22 are fastened to each other by each fastening bolt 23 in a state that each wheel fastening surface 21b of the flywheel 21 and a cover fastening surface 22d of each fastening part 22b are in contact with each other. The cover fastening surface 22d is composed of a friction surface having a prescribed friction coefficient so as to prevent a relative radial slip, caused by centrifugal force, between the cover fastening surface 22d and the wheel fastening surface 21b even when centrifugal force applied to the fastening part 22b is increased as the rotation speed N<SB>FW</SB>of the flywheel 21 goes from a low-rotation region to a high-rotation region. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a clutch device, and more particularly to a clutch device in which a flywheel and a clutch cover are fastened together with a fastening member such as a bolt so that they cannot rotate relative to each other.

  In general, a clutch device is known to transmit / cut off a driving force from a driving source. In particular, in a vehicle equipped with a manual transmission (manual transmission), the power between the engine and the manual transmission. It is well known that it is provided in the transmission path and transmits and blocks torque from the engine to the manual transmission.

  Such a clutch device provided in the vehicle engages / releases according to the depression operation of the clutch pedal when starting the vehicle or switching the gear stage of the manual transmission. Torque is transmitted or cut off.

  This type of clutch device uses a flywheel attached to an engine output shaft, a clutch disc coupled to an input shaft of a manual transmission so as to be integrally rotatable, and an urging member such as a diaphragm spring. A pressure plate that is biased toward the pressing side, and a clutch cover that is attached to the flywheel so as to be integrally rotatable and to which one end of a diaphragm spring is attached.

In such a clutch device, the clutch disk and the flywheel are engaged with each other by urging the pressure plate by the urging force of the diaphragm spring. On the other hand, in this clutch device, the other end of the diaphragm spring is in contact with the release fork, the diaphragm spring is deformed as the release fork moves, and the pressure plate is released from the urging force of the diaphragm spring. Yes. As a result, the clutch disk and the flywheel are released when the pressure plate is displaced away from the clutch disk.
In this type of clutch device, the flywheel and the clutch cover are fastened to each other by fastening members such as bolts at the outer edge portions.

  As such a fastening structure between the flywheel and the clutch cover, a step portion is formed on the outer peripheral portion of the clutch cover, and the step portion is engaged with the outer peripheral portion of the flywheel so that the flywheel and the clutch cover There is known a clutch device that employs a fastening structure in which two are connected with each other (for example, see Patent Document 1).

  Further, in the clutch device described in Patent Document 1, the mounting bolt that is inserted through the insertion hole formed in the outer peripheral portion of the clutch cover is tightened into the fastening hole formed in the outer peripheral portion of the flywheel. A cover is fastened to the flywheel.

  In the clutch device described in Patent Document 1 configured as described above, even when loosening occurs in the mounting bolt that fastens the flywheel and the clutch cover, the flywheel and the clutch cover are joined in-row, While allowing the thermal deformation of the flywheel by the clearance at the inlay joint, further thermal deformation of the flywheel can be regulated.

  By the way, in recent years, in order to improve the response at the time of acceleration of the vehicle, there has been proposed one in which the moment of inertia of the clutch device is reduced by reducing the size in the radial direction of the clutch device and making it compact.

  As shown in FIG. 6, this type of clutch device 80 has a fastening portion 81 a for fastening a clutch cover 81, which has been reduced in size with a reduction in size, to the flywheel 82. The fastening portion 81 a is formed to protrude from the outer peripheral portion of one side surface portion of the clutch cover 81 facing the flywheel 82 toward the flywheel 82, and a plurality of the fastening portions 81 a are arranged at predetermined intervals in the circumferential direction of the outer peripheral portion of the clutch cover 81. Has been.

The clutch device 80 is configured such that the clutch cover 81 and the flywheel 82 are fastened by the inlay coupling of the fastening portion 81a of the clutch cover 81 to the outer peripheral portion of the flywheel 82 via the fastening bolt 83. It has become.
The clutch device 80 projects the components such as the clutch disc 84 so as to be housed inside the clutch cover 81, only the flywheel 82 side by a predetermined length L ₀ fastening portion 81a is in the axial direction of the clutch cover 81 Is formed.

Japanese Utility Model Publication No. 01-128044

However, in the above-described conventional clutch device 80, since the fastening portion 81a of the clutch cover 81 is formed to protrude in the axial direction, the clutch cover 81 and the flywheel 82 are fastened through the fastening portion 81a. The length L _B0 in the axial direction of the fastening bolt 83 is set longer than that of the mounting bolt described in Patent Document 1.

In addition, the spigot coupling portion between the fastening portion 81a and the flywheel 82 the clutch cover 81 being spigot coupling, there may be a slight gap d ₀ due like machining accuracy is formed.

Therefore, when the clutch device 80 rotates at a high speed, a centrifugal force (indicated by an arrow F _A in the figure) acts on the fastening portion 81a more than when the clutch device 80 rotates at a low speed. At this time, stresses shown in the stress distribution of FIG. In FIG. 7, a portion where the distance between the hatching lines of the flywheel 82 and the fastening bolt 83 is small indicates that the stress is large, and a portion where the distance is large indicates that the stress is moderate, and non- The hatched portion indicates that the stress is small.

  That is, as shown in FIG. 7, when a large centrifugal force acts on the fastening portion 81a of the clutch cover 81 that rotates at a high speed together with the flywheel 82, the fastening bolt 83 is caused to deform in the radially outward direction of the fastening portion 81a. Bending stress due to centrifugal force occurs.

  For this reason, in this conventional clutch device 80, in addition to the bending stress resulting from the centrifugal force described above, a large shear stress is generated at the fastening portion between the clutch cover 81 and the flywheel 82. Therefore, there is a problem that the fastening bolt 83 may be broken at the fastening portion between the clutch cover 81 and the flywheel 82.

  The present invention has been made to solve the above-described conventional problems, and reduces the stress generated in the fastening bolts that fasten the flywheel and the clutch cover at the respective outer peripheral portions due to centrifugal force. It is an object of the present invention to provide a clutch device that can be used.

  In order to achieve the above object, a clutch device according to the present invention includes (1) a flywheel and a clutch disk disposed coaxially with the flywheel so as to face the flywheel, and the flywheel and the A clutch device that transmits or cuts power by engaging or disengaging a clutch disc, and houses the clutch disc and has a cover body having an outer peripheral portion, and projects from the outer peripheral portion to the flywheel side. A clutch cover that is formed and has a plurality of fastening portions arranged at predetermined intervals in the circumferential direction; and a fastening bolt that fastens the flywheel and the clutch cover. The fastening portion includes the flywheel. And the flywheel is opposed to the cover fastening surface. The flywheel and the clutch cover are axially fastened with the fastening bolt in a state where the wheel fastening surface and the cover fastening surface are in contact with each other, and the flywheel rotates. Even when the centrifugal force applied to the fastening portion of the clutch cover increases as the speed goes from the low rotation region to the high rotation region, the centrifugal force is generated between the cover fastening surface and the wheel fastening surface. In order to prevent relative sliding in the radial direction, at least one of the cover fastening surface and the wheel fastening surface is constituted by a friction surface having a predetermined friction coefficient.

  With this configuration, at least one of the cover fastening surface and the wheel fastening surface has a predetermined coefficient of friction so that relative slip in the radial direction due to centrifugal force does not occur between the cover fastening surface and the wheel fastening surface. Since the friction surface is used, the radial direction between the cover fastening surface and the wheel fastening surface is increased even if the centrifugal force applied to the fastening portion of the clutch cover increases as the rotational speed of the flywheel moves from the low rotation region to the high rotation region. Relative sliding to is suppressed.

For this reason, it is possible to suppress the stress generated in the fastening bolt due to the centrifugal force generated by the rotation of the flywheel.
As a result, it is possible to prevent the fastening bolt from being broken at the fastening portion between the flywheel and the clutch cover.

  ADVANTAGE OF THE INVENTION According to this invention, the clutch apparatus which can reduce the stress which arises in the fastening bolt which fastens a flywheel and a clutch cover in each outer peripheral part due to centrifugal force can be provided.

It is a schematic structure figure showing the whole clutch device composition concerning an embodiment of the invention. It is a disassembled perspective view which shows the fastening structure of the clutch cover and flywheel of the clutch apparatus which concerns on embodiment of this invention. It is an expanded sectional view of the fastening part of the clutch cover and flywheel of the clutch apparatus which concerns on embodiment of this invention. It is a graph which shows the relationship between the maximum principal stress which arises in the fastening bolt of the clutch apparatus which concerns on embodiment of this invention compared with the conventional clutch apparatus, and the rotational speed of a flywheel. It is a figure which shows the modification of the clutch apparatus which concerns on embodiment of this invention, Comprising: It is an expanded sectional view of the fastening part of the clutch cover and flywheel in the modification. It is an expanded sectional view of the fastening part of the clutch cover and flywheel of the conventional clutch apparatus. It is a figure which shows the stress distribution which arises in the fastening bolt and flywheel in the conventional clutch apparatus.

  Hereinafter, a clutch device according to an embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, a clutch device 10 according to the present embodiment is provided in a power transmission path between an engine 1 and a manual transmission (not shown) in a vehicle equipped with a manual transmission (manual transmission). Transmission and interruption of torque from the engine 1 to the manual transmission is performed.

The clutch device 10 is a so-called push-type clutch device, and includes a clutch mechanism 20 and a clutch release cylinder (CSC: Concentric Slave Cylinder) mechanism 30.
In this embodiment, a push-type clutch device will be described, but a so-called pull-type clutch device may be used.

  The clutch mechanism 20 includes a flywheel 21, a clutch cover 22, a fastening bolt 23, a clutch disk 24, a pressure plate 25, a spring retainer 26, and a diaphragm spring 27.

  The flywheel 21 is connected to the output shaft 2 of the engine 1 by a plurality of bolts 2a, so that the flywheel 21 has a so-called rotational inertial mass and suppresses the occurrence of rotation unevenness of the engine 1.

The flywheel 21 according to the present embodiment has a smaller diameter than the conventional flywheel in order to reduce the moment of inertia of the clutch mechanism 20. As a result, the response and speed change performance at the time of vehicle acceleration, or the so-called N-racing up, in which the driver makes the engine open in the neutral range with the accelerator opening fully open, is improved.
Further, an annular convex portion 21 a that protrudes toward the clutch cover 22 is formed on the outer peripheral portion of the flywheel 21.

  Here, a wheel fastening surface 21 b to which the clutch cover 22 is fastened is formed on the radially inner side of the annular convex portion 21 a of the flywheel 21. The wheel fastening surface 21b is formed with screw holes 21c at a plurality of locations at predetermined intervals in the circumferential direction. A fastening bolt 23 is screwed into the screw hole 21c.

  The clutch cover 22 includes a cover body 22a and a fastening portion 22b. The clutch cover 22 is fastened to the flywheel 21 by fastening bolts 23 and rotates integrally with the flywheel 21.

  The cover main body 22a is formed in an annular substantially disk shape, and a diaphragm spring 27 is attached to the inner side in the radial direction via a plurality of spring retainers 26. The diaphragm spring 27 has a plurality of levers, and a plurality of levers are arranged radially along the inner periphery of the cover body 22a.

  As shown in FIG. 2, a plurality of fastening portions 22b are arranged at predetermined intervals in the circumferential direction of the outer peripheral portion of the cover main body 22a, and are formed to protrude from the outer peripheral portion of the cover main body 22a to the flywheel 21 side. The fastening portion 22b is formed with an insertion hole 22c through which the fastening bolt 23 is inserted.

Further, as shown in FIG. 3, the fastening portion 22b has a predetermined length in the axial direction of the output shaft 2 (see FIG. 1) so that the clutch cover 22 can accommodate components such as the clutch disk 24 therein. only L ₁ are formed to protrude flywheel 21 side.

Further, the predetermined length L ₁ ensures rigidity that the clutch cover 81 can withstand the specifications of the clutch disk 24 and the pressure plate 25 or the centrifugal force generated at the maximum rotation speed of the clutch mechanism 20. Set to length.
In addition, the fastening portion 22b is in-row coupled on the radially inner side of the annular convex portion 21a of the flywheel 21.

  Further, a cover fastening surface 22d facing the wheel fastening surface 21b is formed at the end of the fastening portion 22b on the flywheel 21 side. The cover fastening surface 22d is configured to come into contact with the wheel fastening surface 21b when the fastening portion 22b is in-joined with the annular convex portion 21a.

Further, the cover fastening surface 22d is composed of a friction surface that has been subjected to a roughening process so as to increase the friction coefficient compared to the conventional case in order to prevent relative sliding with the wheel fastening surface 21b. As the surface treatment for roughening, various treatment methods are conceivable. For example, sandblasting, thermal spraying, cutting, or other processing that changes the surface shape can be realized.
The cover fastening surface 22d may be coated with a resin material having a relatively large friction coefficient, for example, instead of the roughening treatment.

For example, the fastening bolt 23 having the same configuration as the conventional fastening bolt 83 shown in FIG. 6 can be used, and the length in the axial direction is set to the length L _B1 . This length L _B1, corresponding to the axial length L ₁ of the output shaft 2 of the fastening portion 22b of the clutch cover 22 (see FIG. 1), and is set to the optimum length.

  The fastening bolt 23 is inserted into the insertion hole 22c of the fastening portion 22b and engaged with the engagement hole 21c in a state where the wheel fastening surface 21b and the cover fastening surface 22d are in contact with each other. As a result, the flywheel 21 and the clutch cover 22 are fastened and fixed in the axial direction of the output shaft 2 (see FIG. 1).

  As shown in FIG. 1, the clutch disc 24 is disposed coaxially with the flywheel 21 between the flywheel 21 and the pressure plate 25, and is relative to the input shaft 3 of the manual transmission (not shown) in the radially inner portion. Splined so that it cannot rotate.

Further, the clutch disc 24 is provided with facing members 24a and 24b which are in contact with the flywheel 21 and the pressure plate 25, respectively, on the side surface on the flywheel 21 side and on both side surfaces on the pressure plate 25 side. The facing members 24a and 24b are attached to the clutch disc 24 by a fixing member such as a rivet.
The facing members 24a and 24b are made of a material having a high coefficient of friction such as glass fiber, phenol resin, rubber, and a friction modifier, and are formed in an annular shape with a predetermined plate thickness.

  The clutch disc 24 is provided with a torsion spring 24c. When the flywheel 21 and the clutch disc 24 are in an engaged state, the torsion spring 24c causes a rotational pulsation of the flywheel 21 or a shock at the time of engagement. The driving force from the engine 1 (see FIG. 1) is transmitted to the input shaft 3 of the manual transmission.

  The pressure plate 25 is made of, for example, an annular member made of cast iron, and is spaced apart from the flywheel 21 in the axial direction. The pressure plate 25 is attached to the clutch cover 22 via a leaf spring (not shown) so that the axis of the input shaft 3 and the axis of the pressure plate 25 coincide. And the pressure plate 25 is urged | biased by this leaf | plate spring so that a movement in the direction separated from the flywheel 21 is possible.

  The pressure plate 25 presses the clutch disc 24 toward the flywheel 21 by the urging force of the diaphragm spring 27. Thereby, the facing member 24a and the flywheel 21 are frictionally engaged, and the facing member 24b and the pressure plate 25 are frictionally engaged. Thereby, the flywheel 21 and the clutch disk 24 are engaged.

  On the other hand, when the pressure plate 25 is pressed by the CSC mechanism 30 on the radially inner side of the diaphragm spring 27, the pressure on the flywheel 21 side of the clutch disk 24 is released. The CSC mechanism 30 presses the diaphragm spring 27 by reciprocating an annular piston provided inside according to the supplied hydraulic pressure.

  When the pressing by the pressure plate 25 is released in this way and the facing member 24b and the pressure plate 25 are separated from each other, the clutch disk 24 is movable in the axial direction of the input shaft 3, and the facing member 24a is separated from the flywheel 21. become. As a result, the flywheel 21 and the clutch disc 24 are released.

Therefore, the clutch device 10 transmits or interrupts the driving force between the engine 1 and a manual transmission (not shown) by engaging or releasing the flywheel 21 and the clutch disc 24.
The input shaft 3 is rotatably supported by the case 5 via a bearing so that the axis thereof coincides with the axis of the flywheel 21.

  Next, with reference to FIG. 4, the stress which arises in the fastening bolt 23 of the clutch apparatus 10 which concerns on this Embodiment is demonstrated compared with the clutch apparatus 80 (refer FIG. 6) of a conventional structure.

4 is a diagram showing the relationship between the rotational speed N _FW (rpm) of the flywheel 21 and the maximum principal stress σ _max (MPa) generated in the fastening bolt 23 (shown by a solid line in FIG. 4). It is the figure compared with the fastening bolt 83 (it shows with a broken line in FIG. 4) of the conventional clutch apparatus 80 shown in FIG. The engine speed Ne (rpm) and the rotational speed N _FW (rpm) of the flywheel 21 or the flywheel 81 are substantially the same, but the following description is based on the rotational speed N _FW (rpm). Shall be performed.

Here, the horizontal axis indicates the rotational speed N _FW (rpm) of the flywheel 21 or the flywheel 82, and the horizontal axis indicates the maximum principal stress σ _max (MPa) generated in the fastening bolt 23 or the fastening bolt 83. Note that the centrifugal force F _A (N) acting on the clutch device 10 (80) increases as the rotational speed N _FW (rpm) increases. The maximum principal stress σ _max (MPa, N / mm ² ) is a stress including bending stress σ _t (N / mm ² ) and shear stress τ (N / mm ² ) generated in the fastening bolt 23 or the fastening bolt 83. Means the maximum value of.

  In the present embodiment, the low rotation region refers to a rotation region up to about 2000 (rpm), for example, and the high rotation region refers to a rotation region of about 5000 (rpm) or more, for example. Further, a rotation region between the low rotation region and the high rotation region is set as a normal rotation region.

  As shown in FIG. 6, in the clutch device 80 having the conventional structure, the friction coefficient as in the present invention is applied to both the fastening portion 81a of the clutch cover 81 and the connecting surface of the flywheel 82 to which the fastening portion 81a is connected. No surface treatment is applied to increase Accordingly, the coupling surfaces of the fastening portion 81a and the flywheel 82 are both surfaces having a small friction coefficient.

That is, taking the coupling surface of the fastening portion 81a as an example, for example, the fastening portion 81a is arranged so that the centrifugal force acting on the fastening portion 81a of the rotating clutch device 80 faces the F _A (N) and the centrifugal force F _A (N). the frictional force on the coupling surface of the coupling face flywheel 82 F _{1 (N),} the axial force of the fastening bolt 83 F _{b (N),} when the friction coefficient of the coupling surface of the fastening portion 81a and a mu _1, The relationship is F ₁ = μ ₁ × F _b .

Here, the total mass of the components of the clutch cover 81, such as the clutch cover 81, the pressure plate 85, and a spring retainer and a diaphragm spring (not shown) attached to the clutch cover 81 is m (kg), the angular velocity is ω (radians per second: rad / sec, where ω can be expressed by 2πN _FW .) When the distance from the rotation axis center of the clutch cover 81 to the center of the total mass, that is, the action point P is r, the centrifugal force F _A (N) is It is obtained from the relational expression of F _A = mω ² r.

Note that the clutch cover 81, the pressure plate 85, and constituent elements attached to the clutch cover 81 such as a spring retainer and a diaphragm spring (not shown) are each formed in an annular shape. Since they are arranged, there are a plurality of the above-mentioned action points P in the circumferential direction, but one of them is shown for convenience of explanation. Since the above-mentioned total mass including other action points P is dispersed at each action point P, the centrifugal force F _A (N) is also similarly dispersed.

The friction coefficient μ ₁ is such that the frictional force F ₁ (N) is higher than the centrifugal force F _A (N) in a low rotation region and a high rotation region that are equal to or higher than a predetermined rotation speed (eg, 500 rpm) belonging to the low rotation region. The friction coefficient is small (F ₁ <F _A ).

Therefore, in the conventional clutch device 80, from the time when the rotational speed N _FW (rpm) of the flywheel 82 reaches a predetermined rotational speed (for example, 500 rpm) in the low rotational range, the coupling surface of the fastening portion 81a and the flywheel _A relative slip in the radial direction due to the centrifugal force F _A (N) occurs between the coupling surface 82 and the coupling surface 82.

For this reason, as shown in FIG. 4, the maximum principal stress σ _max (MPa) generated in the fastening bolt 83 of the clutch device 80 having the conventional structure is a low rotation region (for example, the rotation speed N _FW (rpm) of the flywheel 82 (for example, 500 rpm), and reaches a maximum before the rotational speed N _FW (rpm) of the flywheel 82 reaches the high rotation range (for example, 5000 rpm).

  On the other hand, in the clutch device 10 according to the present embodiment, a roughening process for increasing the friction coefficient is performed on the cover fastening surface 22d of the fastening portion 22b in the clutch cover 22 (see FIG. 3).

That is, the friction coefficient mu ₂ of the cover fastening surface 22d which roughening treatment is performed is set to a larger friction coefficient than the friction coefficient mu ₁ binding surface of the fastening portion 81a of the conventional clutch device 80. In the present embodiment, the above-mentioned friction coefficient μ ₂ corresponds to the predetermined friction coefficient in the present invention.

Specifically, for example, the centrifugal force acting on the fastening portion 22b of the rotating clutch device 10 is F _A (N), and the cover fastening surface 22d of the fastening portion 22b is opposed to the centrifugal force F _A (N). F ₂ = μ ₂ × F where F ₂ (N) is the friction force exerted on the wheel fastening surface 21b, F _b (N) is the axial force of the fastening bolt 23, and μ ₂ is the friction coefficient of the cover fastening surface 22d. _b .

Here, the centrifugal force F _A (N) and the axial force F _b (N) in the clutch device 10 according to the present embodiment will be described as the same centrifugal force and axial force as those of the conventional clutch device 80.
The friction coefficient μ ₂ is such that the frictional force F ₂ (N) is greater than or equal to the centrifugal force F _A (N) (F ₂ ≧ F _A ) at a predetermined rotational speed (for example, 500 rpm) belonging to the low rotation region. The friction coefficient is set to be

Further, the friction coefficient μ ₂ is determined by the centrifugal force F _A (N (N) between the wheel fastening surface 21b and the cover fastening surface 22d until the rotational speed N _FW (rpm) of the flywheel 21 reaches from the low rotation region to the high rotation region. The friction coefficient is set to such a degree that relative slip in the radial direction due to) does not occur or slight slip occurs.

  Therefore, in the clutch device 10 according to the present embodiment, the relative slip in the radial direction that occurs between the wheel fastening surface 21b and the cover fastening surface 22d is suppressed.

For this reason, the maximum principal stress σ _max (MPa) generated in the fastening bolt 23 of the clutch device 10 according to the present embodiment hardly increases even when the rotational speed N _FW (rpm) is in the high rotational speed region.

Thus, the maximum principal stress σ _max (MPa) generated in the fastening bolt 23 of the clutch device 10 according to the present embodiment increases the centrifugal force F _A (N) as the rotational speed N _FW (rpm) increases. Even in this case, the maximum principal stress σ _max (MPa) generated in the fastening bolt 83 of the clutch device 80 having the conventional structure is significantly reduced.

As described above, the clutch device 10 according to this embodiment, so that the relative sliding in the radial direction by the centrifugal force F _A with the cover fastening surface 22d and the wheel fastening surface 21b does not occur, the cover fastening surface since the 22d and friction surfaces having at least either the predetermined frictional coefficient mu ₂ wheel fastening surface 21b, the fastening portion of the clutch cover 22 according speed N _{FW (rpm)} is toward the high rotation region from the low speed region be the centrifugal force F _a is increased according to the 22b, relative sliding in the radial direction of the cover fastening surface 22d for the wheel fastening surface 21b is suppressed.

Therefore, due to the centrifugal force F _A generated by the rotation of the flywheel 21, it is possible to reduce the bending stress generated in the fastening bolt 23.
As a result, it is possible to prevent the fastening bolt 23 from breaking at the fastening portion between the flywheel 21 and the clutch cover 22.

  In the present embodiment, in order to prevent relative sliding between the cover fastening surface 22d and the wheel fastening surface 21b, the cover fastening surface 22d has been subjected to a roughening process that increases the friction coefficient. Instead of the cover fastening surface 22d, the above-described roughening treatment may be applied to the wheel fastening surface 21b, or the above roughening treatment may be applied to both the wheel fastening surface 21b and the cover fastening surface 22d. Good.

  Further, as shown in FIG. 5, the cover fastening surface is not provided between the wheel fastening surface 21b and the cover fastening surface 22d without performing the above-described roughening treatment on any of the wheel fastening surface 21b and the cover fastening surface 22d. You may comprise so that the friction material 40 corresponding to the shape of 22d may be interposed.

  The friction material 40 may be composed of the same material as the facing members 24a and 24b described above, for example, a material having a high friction coefficient such as glass fiber, phenol resin, rubber, and a friction modifier, but more preferably, It is desirable that the material be used for a wet multi-plate clutch, for example, a material having a high coefficient of friction formed by a mixture of cellulose, diatomaceous earth, phenol resin, or the like.

  In addition, in order to prevent the relative sliding between the wheel fastening surface 21b and the cover fastening surface 22d, the wheel fastening surface 21b is subjected to the same surface processing as the friction surface of the flywheel 21 in contact with the facing member 24a. This surface processing may be abolished.

That is, the surface of the flywheel 21 in contact with the facing member 24a is subjected to a surface modification process for improving wear resistance, but the wheel fastening surface 21b is also flush with the friction surface of the flywheel 21. Therefore, the same surface modification treatment is performed. Therefore, by eliminating the surface modification process on the wheel fastening surface 21b, the friction coefficient of the wheel fastening surface 21b can be increased compared to the friction surface of the flywheel 21.
Further, the same effect can be obtained by eliminating surface processing such as polishing that is normally performed on the cover fastening surface 22d.

Therefore, the relative sliding between the wheel fastening surface 21b and the cover fastening surface 22d is achieved by simply eliminating the surface processing that is normally performed without applying any special surface treatment to either the wheel fastening surface 21b or the cover fastening surface 22d. Can be prevented.
In addition, by eliminating such surface modification processing and polishing processing, it is possible to reduce the cost associated with each processing or processing.

  As described above, the clutch device according to the present invention has an effect that it is possible to reduce the stress generated in the fastening bolt that fastens the flywheel and the clutch cover at the respective outer peripheral portions due to the centrifugal force. In addition, the present invention is useful for all clutch devices in which the flywheel and the clutch cover are fastened together with a fastening member such as a bolt so that they cannot rotate relative to each other.

DESCRIPTION OF SYMBOLS 10 Clutch apparatus 20 Clutch mechanism 21 Flywheel 21b Wheel fastening surface 22 Clutch cover 22a Cover main body 22b Fastening part 22d Cover fastening surface 23 Fastening bolt 24 Clutch disc 40 Friction material

Claims (1)

A flywheel and a clutch disk disposed coaxially with the flywheel so as to face the flywheel, and transmitting or cutting power by engaging or releasing the flywheel and the clutch disk A clutch device,
A clutch cover having a cover body that houses the clutch disk and has an outer peripheral portion; and a plurality of fastening portions that are formed to protrude from the outer peripheral portion toward the flywheel and are arranged at predetermined intervals in the circumferential direction;
A fastening bolt for fastening the flywheel and the clutch cover;
The fastening portion has a cover fastening surface facing the flywheel;
The flywheel has a wheel fastening surface facing the cover fastening surface;
In the state where the fastening bolt is in contact with the wheel fastening surface and the cover fastening surface, the flywheel and the clutch cover are fastened in the axial direction,
Even when the centrifugal force applied to the fastening portion of the clutch cover increases as the rotational speed of the flywheel moves from the low rotation region to the high rotation region, it is between the cover fastening surface and the wheel fastening surface. A clutch characterized in that at least one of the cover fastening surface and the wheel fastening surface is formed of a friction surface having a predetermined friction coefficient so that a relative slip in the radial direction due to the centrifugal force does not occur. apparatus.

Images