JPH0565551B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a paper base material for a wet friction material used in oil. Wet friction materials are widely used in multi-disc clutches for automatic transmissions in automobiles and other vehicles.

[Prior Art] The friction plate of a multi-plate clutch is constructed by pasting paper facings in the shape of a hollow disk, as shown in Figure 4, made from a paper base material on both sides of a core bar. . To manufacture this paper facing, a flat paper material is formed by a papermaking method from a papermaking stock solution containing a fiber component such as pulp and a filler such as cashew dust.
A commonly used method is to punch out a predetermined hollow disc shape from a paper material to obtain a paper base material, impregnate this paper base material with a binder such as a phenolic resin, and then harden it.

By the way, when punching a hollow disc-shaped paper base material from a flat paper material, there is a problem that a considerable amount of the paper material is wasted and the yield of the material is poor. For example, in Japanese Patent Application Laid-Open No. 62-72937,
A paper making section in the form of a circular concave groove is provided on the endless moving surface, and paper making stock solution is supplied to the surface while moving the moving surface.
A method is disclosed in which the paper making stock solution on the moving surface is scraped off and paper is made in a paper making section to obtain a paper base material in the shape of a hollow disk. According to this manufacturing method, a punching process is not required, and the yield of the material is improved.

[Problems to be Solved by the Invention] In the method using the paper making section in the form of a circular groove as described above, the paper making section is moved in one direction while the paper making stock solution is supplied, so the orientation direction of the fiber components is the same as that of the flat plate. It is substantially the same as paper material. As a result, the paper base material becomes directional, causing distortion during impregnation and curing of the binder, and the dimensions differing depending on the direction.
There have been cases in which the strength has become directional, resulting in insufficient strength as a friction material.

The present invention has been made in view of the above circumstances, and an object of the present invention is to solve the problem of directionality of paper base materials.

[Means and effects for solving the problem] The method for producing a paper base material of the present invention involves supplying a papermaking stock solution containing a fiber component and a filler to a circular concave groove-shaped papermaking section to form a hollow circle. A method for manufacturing a plate-shaped paper base material, wherein the paper making stock solution is supplied into the paper making section approximately radially from the center of the paper making section, and the paper making stock solution is supplied along the circumferential direction of the paper making section. It is characterized by being supplied with

The fiber component, which is the base component of the paper base material, is as follows:
As in the past, pulps such as linta pulp, organic fibers such as rayon and aromatic polyamide fibers, metal fibers such as brass wire, and in some cases inorganic fibers such as glass fibers and ceramic fibers are used singly or in combination. Available. The shape of the fibers is not particularly limited, and can be selected from among long fibers, short fibers, whiskers, etc. depending on the desired performance.

In addition, fillers are added for the purpose of improving the friction performance and heat resistance of friction materials, and the same materials as conventional ones can be used, such as inorganic fillers such as barium sulfate, calcium carbonate, and clay, and organic fillers such as cashew dust. I can do it.

The papermaking stock solution contains this fiber component and filler, and water is usually used as a dispersion medium. Note that various additives such as stabilizers can also be used in the same manner as in the past. It is desirable that this papermaking stock solution is always supplied to the papermaking section at a constant concentration.

One feature of the present invention is that the papermaking stock solution is supplied substantially radially from the center of the papermaking section. As a result, the fiber components come to be oriented radially, and the paper base material as a whole is oriented in 360 degree directions, so no directionality appears.

Another feature of the present invention is that the papermaking stock solution is supplied along the circumferential direction of the papermaking section. As a result, the fiber components are oriented in the circumferential direction of the paper mesh section,
As a paper base material, it is oriented in 360 degrees as a whole, and no directionality appears. Furthermore, if the fiber components are oriented along the circumferential direction in this way, the shear strength will not be directional when used as a friction material, and there will be no weak parts.

In addition, it is also preferable to rotate the paper screen part during or after feeding substantially radially. In this way, centrifugal force due to rotation acts on the fiber components, causing them to be oriented in the circumferential direction.

The papermaking stock solution supplied to the papermaking section as described above is
The dispersion medium is removed by vacuum suction and paper is made. Then, the formed paper base material is peeled off from the paper mesh section, dried, impregnated with a binder such as a phenol resin, and hardened to form a friction material.

[Effects of the Invention] Therefore, according to the method for producing a paper base material of the present invention, the fiber components in the papermaking stock solution supplied to the papermaking section are oriented in 360 degrees as a whole, so that the directionality is It is possible to easily and reliably produce a paper base material that is Also, the material yield is good. In the friction material formed from the obtained paper base material,
Since there is no directionality, dimensional changes and distortions do not occur, and durability is improved.

Furthermore, since it is a single-shot papermaking method, there is little variation in weight, making it ideal for small-lot, multi-product production with strict standard tolerances.

[Example] Hereinafter, the present invention will be specifically explained using examples. In addition,
In the following examples, a papermaking stock solution having the following composition was used.

Paper making stock solution Rinta pulp 5 parts by weight Diatomaceous earth 3 parts by weight Cassyu dust 2 parts by weight Water 1000 parts by weight Rinta pulp was sufficiently beaten and used by stirring and mixing them thoroughly.

In addition, the dimensions of the paper base material to be formed are 150 mm in outer diameter,
The inner diameter is 80mm and the thickness is 0.5mm.

(Example 1) FIG. 1 shows the main parts of the paper making apparatus used. This papermaking apparatus is comprised of a papermaking section 1 and a supply section 2. As also shown in FIG.
2, a net portion 13 fixed to the cylindrical portion 11 and the conical portion 12 and forming the bottom surface, and a suction portion 14 fixed to the lower part of the net portion 13. And the cylindrical part 11, the conical part 12 and the mesh part 1
3, a circular groove 10 is formed. Conical part 12
The tip has a conical shape, and the apex of the cone is the supply pipe 2.
It is located at the center of the second opening. and conical part 1
2 is made larger than the opening diameter of the supply pipe 22,
The paper making stock solution flowing down from the supply pipe 22 is transferred to the conical part 12.
It is configured so that it always comes into contact with the In addition, the outer diameter and inner diameter of the mesh portion 13 are the same as the dimensions of the intended paper base material, the depth is 0.5 mm, and the mesh is 85 mm.
It's mesh.

The supply section 2 is composed of a raw material tank 20 in which papermaking stock solution is stored, a valve 21, and a supply pipe 22. In addition, as shown in FIG. 3, the valve 21
It is also preferable to have a configuration in which an adjustment tank 23, an overflow tank 24, a pump 25, and a valve 26 are provided between the supply pipe 22 and the supply pipe 22. In this way, it is possible to prevent the supply amount from the supply pipe 22 from fluctuating due to fluctuations in the height of the liquid level in the raw material tank 20.

Using a paper machine configured as shown in Figure 1,
A paper base material was manufactured as follows. First, valve 2
1 is opened, and the papermaking stock solution is allowed to flow down from the supply pipe 22 to the papermaking section 1. At this time, the papermaking stock solution flows down from the apex of the conical part 12 along the side surface of the conical part 12, flows radially, and is supplied into the circular groove 10. Therefore, the orientation direction of the fiber components is approximately radial, and the fiber components as a whole are oriented in each direction of 360 degrees.

Then, by suctioning water in the suction section 14, the fiber components, filler, etc. remain on the net section 13, and a paper base material is produced.

Next, compressed air is supplied from the lower side of the net portion 13,
The paper base material is peeled off from the net portion 13 due to the pressure. At this time, a suction loader is located above the papermaking section 1, and the paper base material is suctioned by the suction roller and conveyed to the drying position. Then, it is compressed and dried using a hot press at the drying position.

In the obtained paper base material, the orientation direction of the fiber components is radial, and the orientation direction as a whole is oriented in each direction of 360 degrees, so that no directionality occurs.

This paper base material is impregnated with phenolic resin,
It is cured into a hollow disk-shaped clutch facing as shown in FIG. It is then attached to a core metal and used as a multi-plate clutch.

(Comparative Example) A paper base material having the same shape as in Example 1 was manufactured from the same material as in Example 1 based on the method disclosed in JP-A-62-72937. Then, the clutch facing was formed in the same manner.

(Evaluation) For the clutch facings obtained in Example 1 and Comparative Example, the tensile strengths in two orthogonal directions were measured. As shown in FIG. 5, the results show that in the facing of Example 1, there is no difference in tensile strength depending on the direction, whereas in the facing of the comparative example, there is a large difference in tensile strength depending on the direction.

Also, for each facing, the number of revolutions
Durability was measured by the number of cycles until it engaged with a mating material at a high rotation speed of 5000 rpm and broke. As a result, the durability of the facings of Examples was improved by 1.3 to 1.5 times.

Furthermore, a large number of facings were manufactured using the manufacturing methods of Example 1 and Comparative Example, and the amount and frequency of dimensional change of the facings in two orthogonal directions when the shape of the paper base material was used as the standard shape was investigated. In the facings obtained by the manufacturing method of the comparative example, the amount of dimensional change varied depending on the direction, but in the facing obtained in Example 1, there was no directionality in the amount of dimensional change.

From these results, it is clear that the clutch facing manufactured by the method of Example 1 has uniform performance without any directionality.

(Example 2) FIG. 6 shows the main parts of the paper machine used. This device is constructed such that the paper making section 1 is rotationally driven by a motor 3, and does not include a conical section. Furthermore, the supply pipe 22 is the same as in the first embodiment except that it is located above the circular groove 10.

Using this papermaking apparatus, a paper base material was formed in the same manner as in Example 1, except that the papermaking stock solution was supplied from the supply pipe 22 while rotating the papermaking section 1 at a speed of 60 rpm. In the obtained paper base material, the fiber components are oriented in the circumferential direction. Therefore, since it faces each direction of 360 degrees as a whole, there is no directionality.
A clutch facing was then formed in the same manner as in Example 1. This clutch facing is also used in Example 1.
It has the same performance as the one made with.

In this example, the paper stock solution was supplied while rotating the paper making part 1, but even if the paper making part 1 was fixed and the supply pipe 22 was rotated along the circular groove 10, the same paper base material could be supplied. can be manufactured.

(Example 3) In this example, a paper base material was formed by combining the methods of Example 1 and Example 2. That is, the paper making stock solution was supplied from the upper part of the conical part 12, and the whole paper making part 1 was rotated. As a result, the fiber components are oriented along the direction of the resultant force of the radially outward force and the circumferential force, and the fiber components are oriented in a 360 degree direction as a whole, so no directionality occurs.

[Brief explanation of the drawing]

Figures 1 to 5 relate to a manufacturing method according to an embodiment of the present invention, in which Figure 1 is an explanatory diagram of the configuration of the paper making apparatus used, Figure 2 is a perspective view of the main parts of the paper making section, and Figure 3 is FIG. 4 is a perspective view of the formed clutch facing, and FIG. 5 is a diagram showing the results of a tensile strength test. Figure 6 is the second
FIG. 2 is an explanatory diagram of the main parts of the paper making apparatus used in the example. DESCRIPTION OF SYMBOLS 1... Screening part, 2... Supply part, 10... Circular groove, 11... Cylindrical part, 12... Conical part, 13...
Net part, 20...raw material tank, 22...supply pipe.

Claims (1)

[Scope of Claims] 1. A method for producing a paper base material in the shape of a hollow disc by supplying a papermaking stock solution containing a fiber component and a filler to a papermaking part in the form of a circular concave groove and making paper, the method comprising: A method for producing a paper base material for a wet friction material, characterized in that a papermaking stock solution is supplied into the papermaking section substantially radially from the center of the papermaking section. 2. A method for producing a paper base material in the shape of a hollow disk by supplying a papermaking stock solution containing a fiber component and a filler material to a circular concave groove-shaped papermaking section and making paper, the method comprising supplying the papermaking stock solution to the papermaking mesh section. 1. A method for producing a paper base material for a wet friction material, characterized in that the paper base material is supplied along the circumferential direction of the part.