JPH075316Y2 - Friction engagement device for automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a brake device and a clutch device of an automatic transmission.

(B) Conventional Technology As a conventional brake device for an automatic transmission, there is a type in which a spring that applies a returning force to a piston is fixed to a spring fixing plate. That is, when it is not possible to secure a space in which the spring directly contacts the front surface of the piston, the spring is arranged on the outer peripheral side of the friction plate, and the force of the spring is transmitted to the piston through the spring fixing plate. To do. The spring is arranged on the outer peripheral protruding portion of the spring fixing plate, and the outer peripheral protruding portion of the spring fixing plate is arranged in the groove portion provided in the casing so as to correspond to the outer peripheral protruding portion. The opposite end sits behind the groove in the casing. The piston receives a force from the spring via the spring fixing plate, and exerts a pushing force on the friction plate via the spring fixing plate. With the configuration as described above, it is possible to prevent the axial dimension of the brake device from increasing due to the arrangement of the spring.

(C) Problems to be Solved by the Invention However, the conventional brake device as described above has the following problems.
When the spring fixing plate moves in the axial direction together with the piston, the outer peripheral protrusion interferes with the groove portion of the casing, and the groove portion of the casing is scraped. When the casing is scraped, abrasion powder is generated, and the abrasion powder is mixed with the hydraulic fluid of the automatic transmission. Therefore, sticking of the valve is likely to occur. The present invention aims to solve such problems.

(D) Means for Solving the Problems The present invention is a member that accommodates laminated friction plates 38 and 42.
10, the piston 18 that presses the friction plates 38, 42 by the hydraulic pressure on one surface side, and the friction plates 38, 42 for applying the returning force that opposes the hydraulic pressure of the piston 18
Coiled springs 28 arranged at multiple locations around the
And one end of the spring 28 has an outer peripheral protrusion 30 of a spring fixing plate 26 provided corresponding to the spring 28.
The spring fixing plate 26 is arranged so as to contact the other surface side of the piston 18, and the outer peripheral projection 30 of the spring fixing plate 26 receives the friction fixing plate 26 with a predetermined clearance. 38, 42
Is arranged on the inner periphery of the member 10 for housing the
In the friction engagement device of the automatic transmission, the other end of which is seated on the bottom surface of the groove portion 34, the guide portion 32 extending in the spring axial direction is provided at the circumferential edge of the outer peripheral protrusion 30 of the spring fixing plate 26. Is provided. The reference numerals represent members corresponding to the examples described later.

(E) Action When hydraulic pressure acts on the piston, it moves forward against the force of the spring acting via the spring fixing plate. The spring fixing plate also moves with the piston. The outer peripheral protrusion of the spring fixing plate moves along the groove portion of the casing. At this time, since the outer peripheral protruding portion is provided with the guide portion, even when the groove portion is contacted, the guide portion is also contacted. Since the guide portion has a relatively large contact area, the surface pressure of the contact portion is small, and the groove portion is not worn.

(F) Embodiment As shown in FIG. 1, a drum 14 is fixed to a casing 10 by a snap ring 16. A piston 18 is fitted on the drum 14. The outer diameter portion and the inner diameter portion of the piston 18 are sealed by sealing members 20 and 22, respectively. A predetermined hydraulic pressure can be applied to the oil chamber 24 formed by the drum 14 and the piston 18. A spring fixing plate 26 is arranged on the left end surface side of the piston 18 in FIG. One end of a coil-shaped spring 28 is fixed to the spring fixing plate 26. As shown in FIG. 2, the spring fixing plate 26 has a shape in which the central portion of the disk is removed in a circular shape, and has outer peripheral protruding portions 30 at four outer peripheral portions. 3 springs on each outer protrusion 30
28 is stuck. The circumferential edge of the outer peripheral protrusion 30 is bent as shown in FIG. 3, and the guide portion 32 is constituted by this. The outer peripheral protruding portion 30 is arranged so as to correspond to the groove portion 34 provided in the casing 10,
A gap is provided between the outer circumferential protrusion 30 and the groove 34 in the radial direction and the circumferential direction. The groove 34 shown in FIG.
The groove portion 36 other than that is an inner diameter spline with which the outer diameter spline of the friction plate 38 is engaged. spring
The end face of the spring fixing plate 26 opposite to the fixing side thereof is seated on the bottom surface 40 of the groove portion 34. A friction plate is provided on the left side of the spring fixing plate 26 in FIG.
Arranged are alternating stacks of 38 and friction plates 42, which are axially positioned by snap rings 44. The friction plate 38 is the groove 36 described above.
Is stopped by the casing 10 which is a member for accommodating the friction plates 38 and 42, while the friction plate 42 is spline-coupled so as to rotate integrally with another rotating member (not shown).

Next, the operation of this embodiment will be described.

When the oil pressure is not acting on the oil chamber 24, the piston 18 is pushed back by the force of the spring 28 acting through the spring fixing plate 26 and is in the state shown in FIG. In this state, the friction plate 38 and the friction plate 42
Since the pressing force does not act on the brake device, the brake device is deactivated.

Next, when hydraulic pressure acts on the oil chamber 24, the piston 18 moves to the left in FIG. 1 against the force of the spring 28. As a result, the spring fixing plate 26 also moves to the left in FIG. 1 (downward in FIG. 3). At this time, when a force in the rotational direction acts on the spring fixing plate 26 for some reason, the guide brake 32 comes into contact with the wall portion 34a forming the groove portion 34. Therefore, the guide portion 32
Will move while being pressed against the wall portion 34a, but since the guide portion 32 has a sufficient contact area with the wall portion 34a, this occurs when the guide portion 32 is pressed against the wall portion 34a. The surface pressure is low, and the wall 34a is not worn. In addition, the guide portion 32 is a spring fixing plate.
It also prevents 26 from rotating more than a predetermined amount. After all, by providing the guide portion 32, it is possible to prevent the wall portion 34a from being abraded and generating abrasion powder, so that it is possible to prevent this from being mixed in the hydraulic oil to generate a valve stick or the like. You can

As shown in FIG. 4, the tip of the guide portion 32 may have an R shape so that the tip of the guide portion 32 can smoothly contact the wall portion 34a. Further, the guide portion 32 has a fifth
As shown in the figure, it can be constructed by bending in the opposite direction to that of FIG. Also in this case, when the spring fixing plate 26 makes a stroke, the guide portion 32
Thus, the anti-wear effect and the guide effect can be obtained. Further, as shown in FIG. 6, the tip portion of the guide portion 32 shown in FIG. 5 can be formed into an R shape.

(G) Effect of the Invention As described above, according to the present invention, the spring is arranged in the case where the spring is fixed to the spring fixing plate and the spring fixing plate strokes according to the compression of the spring. Since the guide portion is provided on the circumferential edge of the outer peripheral protrusion, even if the spring fixing plate receives a force in the rotating direction during the stroke, the contact pressure with the guide portion lowers the surface pressure and the casing Wear can be prevented.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a view taken along line II-II in FIG. 1, and FIG. 3 is III-III in FIG.
FIG. 4, FIG. 5, FIG. 5 and FIG. 6 as seen along the line are views showing different embodiments. 10 …… Casing, 18 …… Piston, 26 …… Spring fixing plate, 28 …… Spring, 30 …… Outer peripheral projection, 32 …… Guide section, 34 …… Groove section, 40 …… Bottom surface.

Claims (1)

[Scope of utility model registration request] 1. A member 10 accommodating laminated friction plates 38, 42, a piston 18 which presses the friction plates 38, 42 by hydraulic pressure on one surface side thereof, and a piston 18 which opposes the hydraulic force of the piston 18. And a coil-shaped spring 28 arranged at a plurality of positions on the outer circumference of the friction plates 38, 42 for exerting a returning force in a direction. One end of the spring 28 has a spring fixing plate 26 provided corresponding to the spring 28. The spring fixing plate 26 is fixed to the outer peripheral protruding portion 30 of the piston 18 and is arranged so as to contact the other surface side of the piston 18, and the outer peripheral protruding portion 30 of the spring fixing plate 26 receives this with a predetermined clearance. As said friction plate
It is arranged on the inner periphery of the member 10 for accommodating 38, 42 corresponding to a plurality of groove portions 34 provided in the piston sliding direction, and the other end of the spring 28 is seated on the bottom surface of the groove portion 34. In a friction engagement device of a transmission, a guide portion 32 extending in the spring axial direction is provided at a circumferential edge of an outer peripheral protrusion 30 of a spring fixing plate 26, and friction of an automatic transmission is provided. Engagement device.