JP3149131B2 - Wet multi-plate clutch or brake in automatic transmission - Google Patents

Description

The present invention relates to a wet-type multi-plate clutch or brake used for an automatic transmission or the like, and more particularly to a separator plate formed of sintered metal.

(B) Conventional technology Generally, a separator plate of a conventional wet multi-plate clutch or brake is formed by stamping a special steel strip (for example, S35CM).

Since the separator plate of the wet multi-plate clutch and the separator plate of the wet multi-plate brake have the same structure as the friction plate and have the same functions, the separator plate of the clutch will be described below.

(C) Problems to be Solved by the Invention However, the surface of the separator plate made of specially polished steel strip is very dense and smooth, so that when the clutch is engaged, that is, when the separator plate is pressed against the clutch plate (friction member). Occasionally, the frictional force becomes large with respect to the clutch plate to be rubbed, and as a result, if the lubricating oil pressure is not sufficiently supplied, the separator plate and the clutch plate may be quickly deteriorated.

In addition, because the separator plate uses the surface of the special steel strip itself,
When the surface condition is different or when punching,
There is a problem that it is difficult to satisfy the requirement of dimensional accuracy due to occurrence of surface scratches.

Therefore, the present invention provides a wet type multi-plate clutch (or brake) having a clutch plate (or brake)
It is an object of the present invention to provide a wet multi-plate clutch or brake in an automatic transmission that can ensure excellent lubrication performance between a friction member such as a plate.

(D) Means for Solving the Problems The present invention has been made in view of the above-described circumstances, and is directed to a wet-type multi-disc clutch for moving a predetermined rotating element of a planetary gear unit (U) and an input member (3) apart from each other. 1) and an automatic transmission comprising a wet multi-plate brake (2) for appropriately locking a predetermined rotating element of the planetary gear unit (U), wherein the wet multi-plate clutch or brake has a friction member having paper on its surface. (6, 11), a separator plate (5, 10) that slidably contacts the surface of the friction member and transmits rotational force;
, Wherein the separator plate is formed of sintered metal having a porous surface.

(E) Operation Based on the above configuration, in the wet multi-plate clutch (1) or the wet multi-plate brake (2) used in a lubricating environment, the clutch plate (6) and the brake plate (11) are used.
The separator plates (5) and (10), which are in sliding contact with the paper surface of the friction member and transmit the rotational force, are formed of a sintered metal having excellent lubricity and formability. , (10) have good lubrication between the friction members (6), (11) and are well formed.

In addition, the code | symbol in parenthesis mentioned above does not limit a structure at all.

(F) Example Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing a part of a wet multi-plate clutch and a brake in an automatic transmission of an automobile.

1 is a wet multi-plate clutch, 2 is a wet multi-plate brake, and the wet multi-plate clutch 1 has an intermediate rotation drive member 3 and a separator plate 5 made of sintered metal and slidably mounted in the axial direction. A clutch plate 6 that rubs against the separator plate 5; and a planetary gear unit U that slidably mounts the clutch plate 6 in the axial direction.
Of the wet multi-plate brake 2
A separator plate 10 slidably mounted on the transmission case 9, a brake plate 11 slidably rubbing the separator plate 10, and another ring gear of a planetary gear unit U for mounting the brake plate 11 slidably in the axial direction. It is composed of 12. The wet multi-plate clutch 1 eliminates a difference in rotation speed between the intermediate rotation drive member 3 and the ring gear 7, and the wet multi-plate brake 2 is mounted on a case 9 of the transmission, that is, a stationary body. The rotation speed of the ring gear 12 is adjusted to zero, that is, the brake is applied to make the rotation speed of the ring gear 12 zero. The action between the separator plate 5 and the clutch plate 6 is performed between the separator plate 10 and the brake plate 11. Is exactly equivalent to the action of

Therefore, for example, the separator plate 5 and the clutch plate 6 will be described with reference to the explanatory view of FIG.
When the axial force P acts on the separator plate 5, the frictional coefficient μ corresponding to the axial force P causes the frictional force μ between the frictional member 6 and the paper on the clutch plate surface.
When P is generated and the center radius of the frictional force μP is R,
It transmits torque only for μPR. In addition,
FIGS. 3 to 5 show plan views of separator plates 5a, 5b, 5c formed of sintered metal. In the separator plate 5c, a plurality of oil grooves 15 as shown in FIG. 6, which is a sectional view taken along the line AA in FIG. 5, are provided on both the front and back surfaces in the radial direction.

Reference numeral 16 denotes a projection protruding from the outer periphery of the separator plates 5a, 5b, 5c. The projection 16 slidably engages with an axial guide groove 17 provided on the peripheral surface of the intermediate rotation driving member 3. are doing. Further, an oil reservoir 20 is provided on an end surface of the projection 16.

In addition, the sintered metal is filled with the required metal in powder without lowering its purity, pressurized and heated at a high temperature below the melting point and bonded to each other to excel in dense mechanical and physical properties. It is formed into a sintered body, and is filled in a mold or pressed by the metal powder in a suitable sintering furnace (usually an electric heating furnace).
When re-pressing is performed after sintering, considerable accuracy is improved, a uniform and constant cross-sectional shape can be secured, and a porous shape peculiar to the surface of sintering has an oil impregnating effect, which is effective for lubrication.

In addition, since it is manufactured by pressing with a mold, when an oil groove on the surface is also required, it can be processed during sintering, and no additional machining is required.

Further, it is much more advantageous than precision casting and precision forging in terms of material yield.

Since the present embodiment is configured as described above, when the axial force P acts on the separator plate 5, a lubricating oil film 13 is formed between the separator plate 5 and the clutch plate 6. At this time, since the surface of the separator plate 5 is porous, lubrication is effectively performed, and the surface of the separator plate 5 is uniform. There is no seizure or the like between the plate 6 and the power is smoothly transmitted.

It is not necessary to form grooves on the clutch plate 6 and the brake plate 11 as in the prior art, but if necessary, free press the sintering mold as shown in FIG. A simple groove shape 19 can be easily provided on the surface of the separator plate 5d.

(G) Effects of the Invention As described above, according to the present invention, since the surfaces of the separator plates (5) and (10) are porous,
A lubricating oil film (13) is stably formed between the separator plates (5) and (10) and friction members such as the clutch plate (6) and the brake plate (11), and the separator plates (5) and (10) ) Has a uniform friction coefficient (μ) because the surface is uniform, and the separator plate (5),
Power can be smoothly transmitted between (10) and the friction members (6) and (11), and the separator plate and the friction member can be prevented from being deteriorated early.

Further, since the required surfaces can be secured while the separator plates (5) and (10) are sintered and the material is kept well, manufacturing costs can be reduced and mass production is easy.

Further, in an automatic transmission, the clutch is shifted by clutch-to-clutch, i.e., a wet-type multi-plate clutch or a wet-type multi-plate brake, and the wet-type multi-plate clutch or the wet-type multi-plate brake corresponds to the operating hydraulic pressure. However, as described above, the separator plates (5) and (10) having a porous surface and the friction members (6) and (6) having a paper surface are required.
In combination with (11), even if the lubrication state changes, a stable lubricating oil film (13) can be formed, and the high-precision control required for the automatic transmission described above can be stably performed over a long period of time. You can do it.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a wet type multi-plate clutch which is a part of an automatic transmission, FIG. 2 is an explanatory view showing a clutch operation, FIGS. 3 to 5 are plan views of a separator plate, and FIG.
FIG. 5 is a sectional view taken along the line AA in FIG. 5, and FIG. 7 is a plan view of a separator plate in which a complicated groove shape is formed at the time of sintering. 1 ... wet multi-plate clutch, 2 ... wet multi-plate brake, 5,
5a, 5b, 5c, 5d, 10: Separator plate, 6, 11: Friction members (clutch plate, brake plate).

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-51-136506 (JP, A) JP-A-55-69242 (JP, A) JP-A-62-270836 (JP, A) 3353 (JP, U) Actually open 62-117340 (JP, U)

Claims (1)

(57) [Claims] 1. An automatic transmission comprising a wet multi-plate clutch for bringing a predetermined rotary element of a planetary gear unit into contact with and separating from an input member and a wet multi-plate brake for appropriately locking the predetermined rotary element of the planetary gear unit. The wet multi-plate clutch or brake has a friction member having paper on its surface, and a separator plate that slidably contacts the surface of the friction member and transmits rotational force, and the separator plate has a porous surface. A wet multi-plate clutch or brake in an automatic transmission, which is formed by sintered metal.