JP2680632B2 - Lockup clutch facing of torque converter - Google Patents

Description

TECHNICAL FIELD The present invention relates to a torque converter, and more particularly to a clutch facing of a lockup clutch used in a lockup converter.

(Prior Art) A clutch facing 3 of a lockup clutch 2 in a conventional torque converter 1 will be described with reference to FIGS. 1 and 2 of the accompanying drawings.

The lockup clutch 2 pushes the clutch facing 3 against the converter cover 4 due to the increase in pressure in the torque converter 1, and transmits power by frictional force. Here, as shown in FIG. 2, the clutch facing 3 of the conventional lock-up clutch 2 is formed in an annular shape such that inner and outer peripheral edges a and b have smooth concentric circles.
Such a conventional clutch facing 3 may cause lubrication failure when the lockup clutch 2 is slip-engaged as described below. That is, when the clutch facing 3 and the converter cover 4 are slip-engaged with each other, the sliding surface becomes extremely hot due to friction. For this reason, it is necessary to sufficiently cool the sliding surface, and the lubricating oil contained in the clutch facing 3 plays an important role in this cooling. When the clutch facing 3 rotates in the direction of the arrow in FIG. 2 with respect to the converter cover 4, the lubricating oil particles P on the clutch facing 3 are constantly subjected to frictional heat due to slippage and continue to rise in temperature with the lapse of time. The lubricating oil is vaporized. In this case, unless the lubricating oil is replenished, the lubricating function is lost, and the clutch facing 3 is carbonized and peeled off.

As a means for solving such a problem, it is effective to supply the lubricating oil, which is lost due to frictional heat during rotation, into the clutch facing. In order to effectively replenish the lubricating oil to the clutch facing during contact rotation, it is conceivable to provide an oil groove on the surface of the clutch facing. FIG. 5 shows a case where an oil groove is provided on the frictional contact surface side of the clutch facing 3. FIG. 5 (b) shows the case of the oil groove that does not reach the core plate, and FIG. 5 (c) shows the case of the oil groove that reaches the core plate. In any case, since the effective contact area of the clutch facing is reduced by the area of the oil groove existing on the surface, the heat generation energy per unit area is increased. Further, the surface pressure at the time of frictional contact also increases, which causes a rise in temperature of the facing surface. Further, in the case of FIG. 5 (b), when the oil groove F disappears due to the abrasion of the facing surface E, the supply of the lubricating oil becomes impossible and the original function is lost. Further, in the case of FIG. 5 (c), if the cross-sectional area of the oil passage (oil groove) through which the lubricating oil passes is increased, the passing amount of the lubricating oil may increase and the capacity of the lockup clutch may decrease.

As mentioned above, it is not a sufficient solution to provide the oil passage groove on the contact surface to prevent the temperature rise of the clutch facing.

(Means for Solving Problems) The present invention has been made in view of the above problems, and is a surface between the clutch facing 3 and the core plate 5 opposite to the friction surface of the clutch facing. By providing an oil groove in the clutch, lubricating oil vaporized when the clutch is slip-engaged can be forcibly replenished from the inside of the clutch facing. This makes it possible to enhance the lubrication and cooling functions between the surface of the clutch facing 3 and the torque converter cover 4. Unlike the case where the oil groove is provided on the rotating surface described above, problems such as increase in heat generation due to decrease in contact area and decrease in clutch capacity are solved.

(Example) Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

3 (a) to (k) show various embodiments of the clutch facing plate according to the present invention.

FIG. 3 (a) shows an example in which an oil groove is provided over the entire width of the ring. Both ends of each groove are open at the inner and outer edges of the ring, and each groove extends radially from the center of the ring.

FIG. 3 (b) shows an embodiment in which both ends of the oil groove in FIG. 3 (a) are closed.

FIGS. 3 (c) and 3 (d) are examples in which the oil groove of the embodiment of FIGS. 3 (a) and 3 (b) is inclined with respect to a straight line passing through the center of the annulus.

FIG. 3 (e) is an example in which two oil grooves extend continuously in the circumferential direction.

FIG. 3 (f) shows the oil groove in the circumferential direction of FIG. 3 (e) which is intermittently closed halfway.

FIG. 3 (g) shows an embodiment in which a hole is penetrated from the surface of the clutch facing 3. The shape of the hole may be circular or irregular such as square.

FIGS. 3 (h) to 3 (k) are examples in which FIGS. 3 (a) to 3 (g) are combined.

FIGS. 4 (a) to 4 (c) are diagrams comparing the situation of the flow of lubricating oil when the conventional clutch facing and the clutch facing having the oil groove according to the present application are used.

4 (a) shows a friction sliding state of the clutch facing 3, and FIGS. 4 (b) and 4 (c) are enlarged views of the sliding portion.

FIG. 4 (b) shows the flow of lubricating oil in the conventional clutch facing. Conventionally both end faces of clutch facing 3
Only parts A and B are in contact with the lubricating oil. In this state, it is not possible to supply sufficient lubricating oil to the entire surface of the clutch facing which is a porous body when the clutch facing is slidably connected, and it is not possible to replenish the lubricating oil vaporized by friction heat. FIG. 4 (c) shows a supply state of the lubricating oil of the clutch facing according to the present invention. Due to the differential pressure generated in the chambers 6 and 7 in the torque converter 1, the hydraulic fluid flows in the direction of arrow C through the oil groove provided on the clutch facing 3. The vibration applied to the clutch facing 3 with the rotation of the lockup clutch 3 promotes the supply of the lubricating oil in the direction indicated by the arrow D. At the same time, the lubricating oil permeates due to the pressure difference. In this way, a sufficient amount of lubricating oil is always supplied to the clutch facing, and carbonization and separation due to friction are prevented.

As described above, the present invention secures the supply of the lubricating oil by providing the oil groove for supplying the lubricating oil on the surface opposite to the friction side surface of the clutch facing 3 of the lockup clutch which is exposed to a high temperature during the friction coupling, It is intended to eliminate the harmful effects such as carbonization and peeling of the clutch facing.

[Brief description of the drawings]

FIG. 1 is a diagram showing a mechanism of a torque converter having a lockup clutch 2. FIG. 2 is an explanatory view of a conventional clutch facing. FIGS. 3 (a) to 3 (k) are views showing an upper surface and a cross section of various embodiments of the clutch facing according to the present invention. FIG. 4 (a) is a diagram showing a state in which the clutch facing is slidably coupled, and FIGS. 4 (b) and (c) show the states of the flow of the lubricating oil in the conventional clutch facing and the clutch facing according to the present invention. It is the figure which compared. FIGS. 5 (a), (b) and (c) are diagrams when an oil groove is provided on the surface of the lockup clutch. (Explanation of symbols of main parts) 1 ... torque converter 2 ... lock-up clutch 3 ... clutch facing 4 ... converter cover 5 ... core plate 6,7 ... converter chamber

Claims (5)

(57) [Claims] 1. A plurality of oil grooves for permeating and supplying sufficient lubricating oil to the entire friction surface of the clutch facing made of a porous body are provided on the surface opposite to the friction surface. Clutch facing of lockup clutch. 2. The clutch facing according to claim 1, wherein the oil groove extends intermittently or continuously in the circumferential direction. 3. The clutch facing according to claim 1, wherein the oil groove extends alternately from the inner diameter side and the outer diameter side. 4. The clutch facing according to claim 1, wherein the oil grooves are evenly arranged on a surface opposite to the friction surface. 5. The clutch facing according to any one of claims 1 to 3, wherein a circular or irregular through hole is provided from the surface of the clutch facing.