JPH0798025A - Manufacture of friction plate of multiplate friction clutch - Google Patents

Abstract

PURPOSE:To provide manufacturing method for a friction plate of a multistage friction clutch with satisfactory material yield, small number of processes, and a small cost. CONSTITUTION:A thin seamless pipe-like body 5 is formed by extruding metal material 4 having ductility. A collar member 6 is obtained by cutting the pipe- like body 5 into specified length. A diameter of the collar member 6 is reduced at one end 6b while its periheral wall is inclined inward, and then a flat circular body 8 is obtained by pressing. A claw 2 is formed on an outer or inner peripheral edge of the circular body 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a friction plate of a multi-plate friction clutch.

[0002]

2. Description of the Related Art A multi-disc friction clutch which is widely used as a clutch in a vehicle such as a motorcycle has a cylindrical clutch outer and a clutch inner which are radially opposed to each other and are arranged on the same axis. A large number of annular friction plates are respectively mounted on the peripheral surface and the outer peripheral surface of the clutch inner so as to rotate integrally with the clutch outer or the clutch inner, but slidably in the axial direction. The friction plates on the clutch outer side and the friction plates on the clutch inner side are alternately overlapped with each other and arranged in the axial direction.By pressing these friction plates against each other by an appropriate means, the friction force between the friction plates is generated. Power is transmitted between the clutch outer and the clutch inner, and the power transmission is interrupted by releasing the pressure contact force.

As a method for mass-producing the above-mentioned friction plate, there has been conventionally used a casting method such as aluminum die casting,
A method of punching from a thin plate of iron, aluminum or the like by a press, a method of molding with a resin material, etc. have been used.

FIG. 7 is a process diagram showing an example of a conventional method by casting. First, the ingot 01 is melted, poured into a mold, solidified, and then taken out from the mold to obtain a cast product 03 in which a plurality of friction plate materials 02 are integrally cast. Then, the individual friction plate materials 02 are separated from the cast product 03. Since many burrs 04 are formed on the friction plate material 02, deburring is performed, and both sides of the material are further flattened to complete the friction plate 05.

Such a casting method requires a high equipment cost, is difficult to be completely automated, and cannot be said to have a sufficient material yield.

In the method of punching with a press, since an annular friction plate is punched from a plate material, a considerable portion remains on the plate material after being punched into an annular shape, and the material yield is further deteriorated.

Therefore, in order to improve the material yield,
Bending one strip-shaped plate material in the plate surface direction to make it annular,
A method of forming an annular friction plate by abutting and fixing both longitudinal end faces of this plate member or by abutting and abutting both circumferential end faces of two semi-annular plate members is disclosed. It is proposed in Japanese Patent Publication No. 3-244831.

According to this method, it is necessary to join the abutted end faces, and it is difficult to obtain a reliable flat joint at a low cost.

[0009]

SUMMARY OF THE INVENTION In view of the above-mentioned state of the art, the present invention has a further improved material yield and can be manufactured on a completely automated production line with a minimum of manpower, and therefore can be manufactured. An object of the present invention is to provide a method for manufacturing a metal friction plate that is low in cost.

[0010]

Therefore, according to the method of the present invention, a step of extruding a ductile metal material to form a seamless thin-walled tubular body, and cutting the tubular body to a predetermined length. And a step of obtaining a collar-shaped member, and a step of pressing the collar-shaped member so that the peripheral wall of the collar-shaped member collapses inward at one end while inclining inward to form a flat annular body,
And a step of processing a claw portion on an outer peripheral edge or an inner peripheral edge of the annular body.

According to this method, the friction plate is obtained by pressing a collar-shaped member obtained by cutting a seamless thin-walled tubular body formed by extrusion into a predetermined length into a flat annular body. As a result, there is almost no waste of material during this period, and a good material yield can be obtained.

Further, since the collar-shaped member is pressed so that the peripheral wall of the collar-shaped member collapses inward at one end and is flattened inward, the internal stress generated in the collar-shaped member or the annular body by the pressing is compressive stress. Therefore, there is no risk of breaking or cracking in the manufacturing process, and the hardness of the product is high.

In addition, in manufacturing the friction plate, since no joining process is required, the manufacturing is extremely simple, the man-hours and costs are reduced, and the friction plate is highly reliable because there is no joint. Is obtained.

On the annular body formed as described above, the claw portion which engages with the clutch outer or the clutch inner is processed on the outer peripheral edge or the inner peripheral edge. This processing is also easily performed by pressing or the like. It can be carried out.

Therefore, according to the present invention, the friction plate can be manufactured by manpower saving on a completely automated production line, which further reduces the manufacturing cost.

[0016]

[Examples] FIG. 1 is a sectional view showing an example of a multi-disc friction clutch used in a motorcycle. A bottomed cylindrical clutch outer 11 and a clutch inner 12 are arranged on the same axis so as to face each other in the radial direction, and a large number of annular friction plates are provided on the inner peripheral surface of the clutch outer 11 and the outer peripheral surface of the clutch inner 12, respectively. 1 ..., 1 '... are attached.

A driven gear 13 attached to the bottom of the clutch outer 11 meshes with a drive gear on an engine crankshaft (not shown), and the clutch outer 11 is driven by the crankshaft. On the other hand, the clutch inner 12 is fixed at its boss portion 14 to a main shaft of a transmission (not shown), and the rotational force transmitted from the crankshaft to the clutch outer 11 causes friction between the friction plates 1 and 1 '. It is transmitted to the clutch inner 12 by force and further transmitted to the main shaft.

In the friction plate 1 attached to the clutch outer 11 side, a large number of claws 2 are arranged on the outer peripheral edge of an annular body 1a so as to be arranged at equal intervals in the circumferential direction (see FIG. 2). The friction plate 1 engages these claws 2 with an axial groove 15 formed on the inner peripheral surface of the clutch outer 11 so that the friction plate 1 rotates integrally with the clutch outer 11 in the axial direction. Is slidably mounted on. As shown in FIG. 3, the pawl 2 that transmits and receives the rotational force to and from the clutch outer is formed to be slightly thick.

On the friction plate attached to the clutch inner 12 side, a claw 2'like the claw 2 is projected on the inner peripheral edge of the annular body, and the claw is engraved on the outer peripheral surface of the clutch inner 12. It is adapted to engage with the axial groove 15 'formed.

A plurality of the friction plates 1 and 1'on the clutch outer side and the clutch inner side are alternately arranged with their main bodies facing each other in the axial direction.
It is sandwiched between the flange portion 16 of 12 and the pressing plate 17. The pressing plate 17 is fitted to the boss portion 14 of the clutch inner 12 so as to be displaceable in the axial direction, and the flange portion 16 is attached by the spring 18.
It is biased toward the side. Therefore, the friction plates 1 and 1'are brought into pressure contact with each other by the pressing force of the pressing plate 17, and the frictional force between them causes power transmission between the clutch outer and the clutch inner.

When the pressing plate 17 is retracted by the lifter 19 connected thereto against the force of the spring 18, the pressure contact state of the friction plates 1 and 1'due to the pressing force is released, so that power is transmitted. Is cut off.

The method of manufacturing the friction plate 1 according to the present invention will be described below with reference to FIG. FIG. 4 is an explanatory diagram sequentially showing in schematic form the shape of the material that gradually changes through each step.

The friction plate 1 is made of an aluminum alloy which is a metallic material having ductility, and FIG. 4 (a) shows its ingot 3. First, the rod-shaped rough material 4 shown in (b) is cast from the ingot 3. Then, the tubular body 5 of (c) is formed by extrusion from the rough material 4. The tubular body 5 has a circular cross-sectional shape and has a relatively thin wall thickness that is substantially equal to the thickness of the friction plate 1 to be manufactured. Further, since this tubular body 5 is formed by extrusion, it is seamless.

Next, the tubular body 5 is cut into a predetermined length to obtain the collar-shaped member 6 of (d). One friction plate 1 is made from this one collar-shaped member 6 by pressing.
That is, the collar-shaped member 6 is
By pressing in the axial direction so as to reduce the diameter at one end edge 6b, a frustoconical intermediate toroid 7 as shown in (e).
Then, the intermediate annular body 7 is further pressed flatly from above and below to form a flat annular body 8 as shown in (f). Therefore, the outer peripheral edge 8a of the annular body 8 is derived from the edge 6a of the collar-shaped member 6, and the inner peripheral edge 8b of the annular body 8 is derived from the edge 6b of the collar-shaped member 6. Since the aluminum material has sufficient ductility, such plastic working can be performed without any trouble.

When the collar-shaped member 6 is pressed to form the intermediate annular body 7, the thick-walled portion 9 is formed at the end edge 6a (see FIG. 5), and after the annular body 8 is processed. This thick part 9
By punching through the required parts by pressing, thick claws 2 as shown in FIGS. 2 and 3 are formed, and the friction plate 1 is completed as shown in (g). The thick-walled portion 9 may be simultaneously formed on the peripheral edge of the annular ring body 8 when the intermediate annular ring body 7 is pressed flat to form the annular ring body 8.

FIG. 5 is a drawing sequentially showing each step of press working from the collar-shaped member 6 to the flat annular body 8 by changing the sectional shape of the material. In this example, the collar-shaped member 6 is processed into a flat annular body 8 through five steps from (1) to (6).

First, on the edge 6a of the collar-like member 6 of (1),
The thick portion 9 is formed as shown in (2). Then, the collar-shaped member 6 is pressed in the axial direction so that the peripheral wall 20 collapses inward while reducing the diameter of the end edge 6b side, and (3)
The peripheral wall 20 as shown in FIG. ₃ is a _first intermediate annular body 7 ₁ inclined by an angle α with respect to the axial direction. Then, by similar pressing, the second intermediate annular body 7 ₂ having the inclination angle β as shown in (4) passes through the third intermediate annular body 7 having the inclination angle γ as shown in (5). _The degree of processing increases to 3 and the third
The intermediate annular body is further pressed flatly from above and below to form a flat annular body 8 shown in (6). The angles α, β and γ are, for example, 30 °, 50 ° and 70 °, respectively.

FIG. 6 shows an example in which the five steps in FIG. 5 are shortened to three steps. In FIG. 6, in the step (2),
Steps (2) and (3) of FIG. 5, that is, the molding of the thick portion 9 and the molding of the first intermediate torus 7 ₁ are performed at the same time, and the third intermediate torus 7 ₃ 2 The intermediate torus 7 ₂ is pressed into the torus 8 at once.

The internal stress generated in the peripheral wall 20 by such press working is mainly a compressive stress. Therefore, during the working, there is no possibility of breaking or cracking in the peripheral wall 20 and the hardness becomes high, so that it is suitable as a friction plate. A torus 8 is obtained.

The manufacturing steps from (b) to (g) in FIG. 4 are all carried out by plastic working except that the collar-shaped member 6 is cut out from the tubular body 5, and finally the material removed to form the pawl 2. Since the amount of is very small, the material fraction is significantly improved.

Further, since no joining process is required, the number of steps and cost are reduced, and a highly reliable friction plate can be obtained.

Furthermore, since the above manufacturing process can be performed consistently on a completely automated production line, the productivity is improved.

In the above-described embodiment, the thick portion 9 is preliminarily formed on the peripheral portion of the annular body 8 and the thick portion 9 is appropriately punched to form the claw 2. However, the entire thickness is the same. It is also possible to first form a claw on the peripheral portion of the molded annular body 8 and then press the claw portion from the outer peripheral direction to make it thick.

Although the method of the present invention has been described above with respect to the friction plate 1 having the claws 2 on the outer circumference, it goes without saying that the method of the present invention can also be applied to the production of the friction plate 1'having the claws on the inner circumference.

[0035]

According to the present invention, a friction plate in a multi-plate friction clutch can be manufactured with a good material yield without causing breakage or cracks in the manufacturing process.
Further, a highly reliable friction plate can be obtained with a small number of steps and cost, and the productivity of the friction plate is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a multi-plate friction clutch.

FIG. 2 is a plan view showing an example of a friction plate produced by the method of the present invention.

FIG. 3 is a sectional view taken along line II-II in FIG.

FIG. 4 is an explanatory diagram sequentially showing each step of the method of the present invention by changing the shape of the material.

FIG. 5 is a drawing sequentially showing each step of press working from the collar-shaped member to the flat annular body by changing the cross-sectional shape of the material.

FIG. 6 is a drawing similar to FIG. 5, showing the respective steps of the press working in another embodiment in order.

FIG. 7 is an explanatory view similar to FIG. 4, showing a conventional method.

[Explanation of symbols]

1 ... Friction plate, 2 ... Claw, 3 ... Ingot, 4 ... Coarse material, 5 ...
Tubular body, 6 ... collar-shaped member, 7 ... intermediate annular body, 8 ... annular body, 9 ... thick portion, 11 ... clutch outer, 12 ... clutch inner, 13 ... driven gear, 14 ... boss, 15 … Grooves, 16… Flange, 17… Pressing plate, 18… Spring, 19… Lifter, 20
… Peripheral wall.

Claims (1)

[Claims] 1. A step of extruding a ductile metal material to form a seamless thin-walled tubular body, a step of cutting the tubular body into a predetermined length to obtain a collar-shaped member, and the collar-shaped member. Is pressed to form a flat annular body such that its peripheral wall is reduced in diameter at one end and collapses inward, and a step of processing a claw portion on the outer peripheral edge or the inner peripheral edge of the annular body. Method for manufacturing friction plate in plate friction clutch.