JP2576027Y2 - Wave coil spring - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wave coil spring used for a clutch or the like in an automatic transmission of an automobile.

[0002]

2. Description of the Related Art Generally, an automatic transmission (so-called AT) of an automobile tends to be multi-stage in order to improve the power performance and fuel efficiency of the automobile, and a plurality of planetary gears and respective gears constituting the planetary gears are provided. A configuration having a plurality of multi-plate clutches for connecting and disconnecting an input shaft or an output shaft is widely used.

A return spring of a hydraulic piston for driving the multi-plate clutch is disclosed in Japanese Utility Model Laid-Open No. 2-788.
As disclosed in Japanese Patent Application Publication No. 20, a wave coil spring having a lower contact height than conventional coil springs has been used.

[0004]

However, since the wave coil spring has low rigidity against torsion, the positions of the peaks and valleys of the adjacent corrugated portions are shifted unless special measures are taken to prevent the rotation force from acting. It has the disadvantage that the free length changes and it is not possible to exhibit the performance such as restoring force as designed.

[0005] For example, the hydraulic piston in the multi-plate clutch is normally rotatable with respect to a shaft, and is rotatable relative to a retainer of a return spring. For this reason, the return spring interposed between the hydraulic piston and the retainer may be subjected to a rotational force by the hydraulic piston rotating at the time of clutch engagement or the like. In this case, the return spring may be a wave coil spring. In such a case, there is a possibility that the performance is changed due to easy twisting, for example, a problem that the clutch is not completely switched.

[0006] As a means for solving this problem,
As described in Japanese Utility Model Laid-Open No. 2-96054, there is a means for providing a mechanism (guide mechanism) for preventing relative rotation of members (a hydraulic piston and a retainer) at both ends of a return spring. In some cases, such a mechanism is not provided, and there is a problem that a cost increase is large.

Further, by providing a lubricating surface treatment or providing a thrust bearing, frictional resistance between the wave coil spring and members at both ends of the wave coil spring (such as the hydraulic piston) is reduced, and the wave coil spring is provided. Means for addressing this problem by reducing the applied rotational force are conceivable. However, it is impossible to completely eliminate the frictional resistance, and it is not a reliable solution, and this also has a problem that the cost increases greatly.

The present invention has been made in view of such conventional circumstances, and has as its object to provide a wave coil spring which does not twist even when it receives a rotational force.

[0009]

The gist of the present invention for achieving the above-mentioned object lies in the following items. [1] A single continuous strip-shaped thin plate (1) having elasticity is spirally wound a plurality of times continuously in the thickness direction while continuously forming a corrugated portion in the thickness direction. In a wave coil spring in which the peaks and valleys of each adjacent wave portion are opposed to each other, the adjacent wave portions are allowed to freely displace in the vertical direction along the spring axis, and the circumference of the spring is A wave coil spring provided with a locking mechanism (10, 20, 30, 40) for locking each corrugated portion with each other in order to prevent relative displacement in a horizontal direction along the wave coil spring. [2] The locking mechanism (10, 20, 30, 40) is set at a position where the adjacent corrugated portions do not contact in a free state but contact in a compressed state [1]. The described wave coil spring. [3] The locking mechanism (10, 20, 30) is provided with a projection (12, 22, 32) opposing the other waveform portion on one of the adjacent waveform portions and the other waveform portion. In the department,
Receptor sites (1) for receiving the protrusions (12, 22, 32)
1, 1, 31) [1]
Or the wave coil spring according to [2].

[0010]

[Function] With the wave coil spring of the present invention,
The relative displacement of each corrugated part in the horizontal direction along the spring circumference is achieved while the relative displacement of each corrugated part in the vertical direction along the spring axis is free by the locking mechanism provided on each adjacent corrugated part. Mechanical displacement is prevented. Therefore, for example, even if a rotational force is received from the outside, this force is reliably borne by the locking mechanism, and the phase shift of each waveform portion (ie,
Torsion) is prevented. For this reason, the design performance as a spring does not change due to this rotational force.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. This wave coil spring is formed by spirally winding a continuous strip-shaped thin plate 1 having elasticity plural times continuously in the thickness direction while continuously forming a corrugated portion. The peaks and valleys of the waveform portions adjacent to each other in the direction are opposed to each other. When the wave coil spring is in a free state (a state in which no external force is applied), each of the adjacent corrugated portions that are in contact with each other is free from relative displacement of each corrugated portion in the vertical direction along the spring axis. In order to prevent the relative displacement of each corrugated portion in the horizontal direction along the circumference of the spring, a locking mechanism 10 for locking each corrugated portion with each other is provided.

In this embodiment, the locking mechanism 10
But below each of the adjacent waveform portions (one waveform portion)
A convex portion 12 provided as a protrusion facing the upper side (the other waveform portion); and a concave portion 11 provided as a receiving portion for receiving the convex portion 12 on the upper side. Consists of Here, the concave portion 11 and the convex portion 12 can be formed by, for example, press working.

With this wave coil spring,
Not only in the compressed state but also in the free state, the recess 1
The phase shift of each waveform portion is prevented by the locking mechanism 10 including the projections 1 and the projections 12. In particular, at the time of compression, the compressive force acts to press the concave portion 11 and the convex portion 12 against each other.
Torsion (phase shift of the corrugated portion) is reliably prevented, and the performance (restoring force, etc.) as a designed spring is exhibited.

The locking mechanism 10 may be provided at a position where it is not in contact in the free state (during manufacture) but is in contact in the compressed state (used state).
Further, it may be provided at both a position where it contacts in a free state and a position where it contacts in a compressed state. The concave portion 11 and the convex portion 12 of the locking mechanism 10 provided at the position where they come into contact with each other in the compressed state as described above are fitted at the time of compression (when used), and
Since the force resisting the rotational force causing twisting is shared, the force borne by each locking mechanism 10 is further dispersed, and the reliability of the twist preventing function is further improved.

Therefore, if the above-mentioned wave coil spring is used for returning the clutch in the AT, the close contact height (arrangement space) of the return spring is obtained.
And the design performance of this return spring can be exhibited with high reliability, and the reliability of the shift change operation can be maintained at a high level. Further, since the configuration to be added is simple as described above, cost is reduced. The effect is that the increase is small.

The locking mechanism according to the present invention is not limited to the embodiment described above, but may have the following various embodiments.
For example, as shown in FIGS. 4 and 5, a notch 21 formed on one of the adjacent corrugated portions as a receiving portion and a claw 22 formed on the other and serving as a projection engaged with the notch 21. The stop mechanism 20. Also, as shown in FIG.
The locking mechanism 30 includes a hole 31 formed on one of the adjacent corrugated portions as a receiving portion and a claw 32 formed on the other and serving as a projection that engages with the hole 31.

As shown in FIGS. 7 and 8, holes 41 and 42 formed in both of the adjacent corrugated portions, and clips into which the claws 43 and 44 are fitted in the holes 41 and 42 from outside. There may be a locking mechanism 40 consisting of 45.

[0018]

[Effect of the Invention] The wave coil spring according to the present invention does not twist even when a rotational force is applied (the phase of the waveform portion does not shift), so that the design performance is reliably exhibited even when used in a place where the rotational force is applied. be able to. Therefore, this wave coil spring can easily be used as a return spring in an AT clutch with high reliability in place of a conventional coil spring without taking complicated and expensive measures to prevent rotational force from being applied to the wave coil spring. Therefore, the original effect that the contact height can be reduced as compared with a normal coil spring can be achieved without any trouble.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a locking mechanism according to the embodiment of the present invention;

FIG. 3 is a side sectional view showing the locking mechanism according to the embodiment of the present invention;

FIG. 4 is a perspective view showing a first modification of the locking mechanism of the present invention.

FIG. 5 is a side sectional view showing a first modification of the locking mechanism of the present invention.

FIG. 6 is a perspective view showing a second modification of the locking mechanism of the present invention.

FIG. 7 is a perspective view showing a third modification of the locking mechanism of the present invention.

FIG. 8 is a side sectional view showing a third modification of the locking mechanism of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Strip-shaped thin plate 10, 20, 30, 40 ... Locking mechanism 11 ... Concave part (reception part) 12 ... Convex part (projection) 21 ... Notch (reception part) 22 ... Claw (projection) 31 ... Hole (reception part) 32 ... nails (projections) 41, 42 ... holes 43, 44 ... nails

Claims (3)

(57) [Scope of request for utility model registration] 1. A continuous strip having elasticity is spirally wound a plurality of times continuously in the thickness direction while continuously forming a corrugated portion. In a wave coil spring in which peaks and valleys of adjacent corrugated portions are opposed to each other, the adjoining corrugated portions follow the spring circumference while allowing relative displacement in the vertical direction along the spring axis to be free. A wave coil spring having a locking mechanism for locking each corrugated portion to each other to prevent relative displacement in a lateral direction. 2. The wave coil spring according to claim 1, wherein the locking mechanism is set at a position where the adjacent corrugated portions do not contact in a free state but come into contact in a compressed state. 3. The locking mechanism according to claim 1, wherein one of the adjacent waveform portions has a projection opposing the other waveform portion.
3. The wave coil spring according to claim 1, wherein a receiving portion for receiving the protrusion is provided on the other waveform portion.