JPS62274122A - Manufacture of friction plate for automatic transmission - Google Patents

Abstract

PURPOSE:To lengthen a die life, raise the limit of rigidity, and remarkably reduce the cost, by using a friction plate made of a rolled steel plate (SPH material) as a backing plate, etc. CONSTITUTION:A friction plate 1 made of a SPH material, is formed with a hole 2 adapted to be fitted on a driving shaft of an automatic transmission, projected/recessed part 3 for torque transmission, and a friction face 4 which contacts with a disc plate. As hardness of this SPH material, measured before heat treatment, is about Hv170, it is easy to be press-processed. The press- processed friction plate 1 is improved in its hardness, by quenching/tempering the surfaces 4, 5, and finished by polishing the surface as to be under 3z. Hardness of the quenched part is Hv200-800 (in case of carbo-quenching), and depth of it is 0.05-1mm. In this way, the friction plate 1 which is soft at the center part, and is hard at the surface, is formed.

Description

Detailed Description of the Invention Detailed Description of the Invention [Object of the Invention] (Industrial Field of Application) The present invention relates to a method for manufacturing a friction plate, and the invention relates to a method for manufacturing a friction plate, which is a friction plate formed from a rolled steel plate and used as a backing plate for an automatic transmission. used.

(Prior Art) Carbon steel for mechanical structures (hereinafter referred to as SC material) is used as a backing plate for torque transmission in automatic transmissions.

To explain this with reference to Fig. 4 (a), (b), and (c), in the transmission device A of an automatic transmission, 10 is a rotating shaft, 11 is a hydraulic piston, and 12 is a thin plate that fits on the rotating shaft. 13 is a disk plate with friction material glued on both sides, which engages with the rotating shaft 10 through uneven grooves, and 14 is a backing plate, which fits onto the rotating shaft 10 and engages with the drum through uneven grooves on the outer periphery. 15 is a snap ring, and 16 is a drum, which are fitted onto the rotating shaft 10. If the oil pressure P is not applied, the drum 16 is idling even if the rotating shaft 10 rotates, and the oil pressure P
The action causes the piston 11 to move to the right, and the backing plate 14 rotates due to the pressure contact of the friction material of the disc plate.
Therefore, the drum 16 rotates.

In this case, the backing plate has an uneven groove 3 for transmitting torque on its outer periphery as shown in (a) and (b) of FIG. is the surface, and this surface 4 is in contact with the disk plate, and in order to ensure frictional characteristics, as shown in Fig. 2, after press working, quenching and tempering are performed to make the whole hardness about Hv320, and the surface is It is used after being polished to a surface roughness of 3.0z or less.

(Problems to be Solved by the Invention) However, when the backing plate made of the SC material is used as a friction plate for an automatic transmission, the material is expensive, and the hardness of the non-heat-treated material is Hv220 or higher. The problem was that the mold life during pressing was short due to the high hardness of the material itself.

The technical object of the present invention is to provide a friction material made of steel plate that is low in material cost, can be easily pressed, and has a high surface hardness.

[Structure of the invention]

(Means for solving the problems) The technical means taken to solve the above technical problems are as follows.

In other words, it is made of rolled steel (SPH material) with a plate thickness of 3 to 6I and has uneven parts for torque transmission on the outer periphery used in automatic transmissions. The surface is hardened by quenching, and the hardening depth is 0.
05-1. Omm, and its hardness is 1 (in the case of carburizing and quenching)
V200~800. For induction hardening, Hv200~4
00 is a method for manufacturing friction plates for transmissions.

(effect) The technical means works as follows.

That is, when pressing a friction plate using a rolled steel plate, since it is a non-heat treated material and has a hardness of about Hv 170, it is easy to press and the mold life is long. Further, by the heat treatment method, the surface hardness becomes 320 V or higher, the hardness of the inner surface becomes 170 Hv or higher, and a friction plate with excellent friction resistance and toughness is formed.

(Example) Specific examples will be described below.

In Figures 1 (a) and (b), ■ is a friction plate made of rolled steel plate (SPH material), which has a hole 2 that fits into the drive shaft of an automatic transmission, and 3 is an uneven part for torque transmission. , 4 is a friction surface with the disk plate.

The friction plate 1 is manufactured by the process shown in FIG.

In this case, since the SPH material has a hardness of about HvL70 before non-heat treatment, it can be easily pressed.

Next, the surface portions 4 and 5 of the friction plate 1 are hardened and tempered to increase their hardness, and the surfaces are polished to a surface roughness of 3.0z or less. Hardness: H during carburizing
v 200-800. In the case of induction hardening, Hv200~4
00, and the hardening depth is 0°05 to 1. Omm and
This is shown by diagonal lines in FIG.

With this, I! The central part of the five plates is flexible, and the surface part is a hard friction plate.

The backing plate 14 formed in this manner is sandwiched between the disc clutch 13 and the snap ring 15 as shown in FIG. It is used as an X-rubbing board.

〔Effect of the invention〕

The present invention has the following effects.

In other words, by using a friction plate made of SPH material as the backing plate of the A1 transmission, (by changing the material from 11S C material to SPH material, a significant cost reduction can be achieved, and (2) by the surface hardening method. The rigidity limit increases compared to non-heat treated materials, and the safety factor improves (31S P H
When pressing material, the hardness is Hv17 with non-heat treated material.
By setting the value to 0, the mold life will be improved.

[Brief explanation of the drawing]

Figure 1 is an external view of the friction plate of this example, (A) is a side view, (B) is a plan view, Figure 2 is an explanatory diagram of the manufacturing process of the friction plate, and Figure 3 is the hardness of the friction plate. An enlarged view of the distribution, Figure 4 (A) is a cross-sectional explanatory diagram of the usage state, Figure 4 (B) is Figure 4 (A)
B-B sectional view of Figure 4 (C) is C-C of Figure 4 (A)
A cross-sectional view is shown. 1...)g! Friction plate, 2... A hole that fits into the rotating shaft. 3...Irregularities on the outer periphery

Claims (1)

[Claims] Friction plates used in automatic transmissions are made of rolled steel plate (SPH material) with a thickness of 3 to 6 mm and have an uneven part for torque transmission on the outer periphery and a hole to fit into the rotating shaft. The surface is hardened by charcoal hardening or induction hardening, and the hardening depth is 0.05 to 1.0 mm, and the hardness is Hv200 to 800 for carburizing and hardening, and Hv20 for induction hardening.
A method for manufacturing a friction plate for an automatic transmission with a speed of 0 to 400.