JPS63277704A - Flattening treatment for multi-plate type clutch plate - Google Patents

Abstract

PURPOSE:To treat flattening of the clutch plate under excellent yield by grinding and polishing surface of sintering friction material of the multi-late type clutch plate composing of a core material having different material and the sintering friction material and after that, inserting paper between the sintering friction materials of plural clutch plates, pressurizing and heating. CONSTITUTION:The surface of the sintering friction material 2 of the multi-late type clutch plate formed by the sintering friction material 2 composing of soft steel- or high carbon steel-made core plate 1 and Cu base sintering alloy containing 5-10wt.% Sn, 5-10% Pb, 16-18% C, 5-9% one or more kinds among SiO2, ZrO2 or mullite and the balance of Cu, is grinded and polished. After that, by inserting the paper 6 between the sintering friction materials 2 of plural clutch plates, the multi-plate type clutch plates are piled up and heated in a heating furnace 5 under reducing atmosphere at 680 deg.C, while pressurizing by hydraulic pressure cylinder 4 to produce the plural pieces of multi-plate type clutch plates. By this method, the multi-plate type clutch plate is flattened under high yield without sticking between the sintered friction faces.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for flattening multi-plate clutch plates used in vehicles and other industrial machines.

[Conventional technology]

In general, a multi-disc clutch plate is produced by lining a Cu-plated mild steel or high carbon steel core plate with a sintered friction material and heating it, and simultaneously sintering the sintered friction material with the core plate. It was manufactured by diffusion bonding.

FIG. 1 shows a plan view of a multi-disc clutch plate, and FIG. 2 shows a sectional view taken along the line ■-n in FIG. 1.

The multi-plate clutch plate has a structure shown in FIGS. 1 and 2, where 1 is a core plate and 2 is a sintered friction material.

Since the sintered friction material is mainly made of a Cu-based sintered alloy, the core plate and the sintered friction material are made of different metals. Therefore, a difference occurs in the coefficient of thermal expansion and residual stress during the process of heating and diffusion bonding, and after heat diffusion bonding, deformation occurs as shown in the third factor.

FIG. 3 is a side view of a modified multi-plate clutch plate.

In order to correct these deformations, the above diffusion bonded multi-plate clutch plates were stacked with stainless steel plates in between as shown in Figure 4, and then flattened while applying a load and heated. The clutch plate was secured with a magnetic chuck, ground, and then polished.

FIG. 4 shows multi-plate clutch plates consisting of a core plate 1 and a sintered friction material 2 stacked with a stainless steel plate 3 in between, and flattened in a heating furnace 5 while applying a load with a hydraulic cylinder 4. FIG.

[Problem that the invention seeks to solve]

This is the multi-plate clutch plate that has been flattened in this way.

The products are immediately ground and polished in the assembly line, but at the product inspection stage, multi-plate clad plates that are not sufficiently flattened are sometimes discovered.

The surface of the sintered friction material of the multi-disc clutch plate, which was detected at the stage of product calibration, which was not sufficiently flattened, is a polished surface, so the surface is activated.

Therefore, if the stainless steel plates are sandwiched and stacked and then flattened again as in the above conventional method, the polished surface of the sintered friction material and the surface of the stainless steel plate will stick together, and if the stainless steel plates are forcibly removed, the sintered friction material will peel off and re-flatten. Since it is impossible to perform the flattening process by sandwiching the stainless steel plate, in the end, multi-plate clutch plates that were not flattened enough and were detected at the product inspection stage were discarded.

[Failure to solve the problem]

Therefore, the present inventors conducted research to develop a method that would allow flattening even for polished multi-plate clad plates, and found that paper was sandwiched between the multi-plate clad plates instead of the stainless steel plate and heated. We have learned that when flattened, the paper does not stick to the polished multi-plate cladding plates, the paper is heated and carbonized, which prevents the multi-plate cladding plates from sticking together, and the carbon can be easily wiped off. be.

This invention was made based on this knowledge, and involves grinding and polishing the surface of the sintered friction material of a multi-disc clutch plate consisting of a core plate and a sintered friction material, and then polishing the surface of the sintered friction material. The present invention is characterized by a method for flattening a multi-plate clutch plate, in which the multi-plate clutch plates are stacked with paper interposed between the surfaces of the materials, and the stacked multi-plate clutch plates are heated.

In this case, soft 914 or high carbon steel is used for the core material of the multi-disc clutch plate, and the sintered friction material is Sn: 5 to 10.
%, Pb: 5-10%, C: 16-18%, 5102. One or two of zr02 or mullite
Species or more 25 to 9 pieces, (more than 25% by weight)% balance is Cu
It is preferable to use a CU-based sintered alloy containing unavoidable impurities, and heating temperature: 100 to 800°C.

Load: 0.5-20 kg/crn2, paper thickness:
0.01-0.5mm.

They also found that it is preferable to perform the treatment under conditions within the range of .

〔Example〕

First, the present invention will be specifically explained based on examples.

Plate thickness: 1.6r! uX mild steel plate diameter: 140ffll
l! 50 core plates were created by punching out disks and plating them with Cu.

On both sides of the core plate, the composition is SnNia%%Pb:8%
, graphite: 17%, 5i02: 8%, the balance being Cu and unavoidable impurities (' or more weight %) A sintered abrasive material was lined in a ring shape with a thickness of 20.5Q, an outer diameter of 130M, and an inner diameter of 110M. By diffusion bonding, 5° multi-plate clutch plates having the shapes shown in FIGS. 1 and 2 were produced.

This multi-plate clutch plate was attached to a magnetic chuck, and the surface of the sintered friction material was ground and polished while being rotated.

A piece of paper 2,005 mm thick was sandwiched between the polished multi-plate clutch plates, and the 50 multi-plate clutch plates were stacked as shown in FIG. 5 in a reducing atmosphere.

The flattening process was carried out at a temperature of 2,680° C. and a pressure crab of 6 kg/CTL of 2.60 minutes.

In this case, the paper to be inserted may be cut out to a size that does not allow the sintered friction materials to come into contact with each other.
Cut it out into an appropriate shape as shown in the figure and use it.

FIG. 6 is a plan view showing the shape of the paper to be inserted. The shape of the paper to be inserted may be a simple circle as shown in Figure 6(a), but it should be inserted so that the gas in the center can escape during heating.
A paper having radial cuts 7 as shown in FIG. 6(b), or a band 8 as shown in FIG. 6(c).
It is preferable to use one having a radial shape.

When the flatness of the 50 multi-plate clutch plates subjected to the above flattening process was measured using a three-dimensional measuring machine, three of the 50 plates did not have sufficient flatness and were rejected.

When the three rejected multi-plate clutch plates were flattened again in the next batch, sufficient flatness was obtained this time.

〔Effect of the invention〕

As mentioned above, if stainless steel plates were conventionally used as the sandwiching members during heating and flattening treatment, multi-plate clutch plates that failed product inspection would have to be discarded. By heating and flattening the paper by sandwiching it as shown in the figure, multi-plate clutch plates that were previously discarded can be flattened again, which has the excellent effect of eliminating the need to discard them.

[Brief explanation of the drawing]

Figure 1 is a plan view of a multi-disc clutch plate, and Figure 2 is a plan view of a multi-disc clutch plate.
Figure 3 is a side view of the deformed multi-disc clutch plate;
The figure is a schematic diagram showing a state in which multi-plate clutch plates are stacked with stainless steel plates in between and charged into a heating furnace. FIG. 5 is a schematic diagram showing a state in which multi-plate clutch plates are stacked with a piece of paper sandwiched between them and charged into a heating furnace. FIG. 6 is a plan view showing the shape of the paper to be inserted. 1... Core plate, 2... Sintered friction material, 3...
...Stainless steel plate, 4...Hydraulic cylinder, 5.
...heating furnace, 6...paper, 7...cut,
8...Obi paper.

Claims (1)

[Claims] In a method for flattening a multi-disc clutch plate comprising a core plate and a sintered friction material, the surface of the sintered friction material is ground and then polished, and the surface of the ground sintered friction material and the surface of the sintered friction material are polished. 1. A method for flattening a multi-plate clutch plate, comprising: stacking the multi-plate clutch plates with paper sandwiched between them; and heating the stacked multi-plate clutch plates.