JP2000074100A - One-way clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a one-way clutch capable of improving reliability of a lock after changing over of OFF-ON by decreasing idling torque of a shaft in a clutch function ON state and increasing energizing force against a rolling member in a clutch function OFF state. SOLUTION: It is made compatible to reduce energizing force of a rolling member 3 in a clutch ON state and to increase energizing force of the rolling member 3 in a clutch OFF state by making a spring 502 to energize the rolling member 3 to a cam surface 1a a two-step spring to increase a spring constant at flexible quantity d2 in the clutch OFF state in comparison with a spring constant at flexible quantity do in the clutch ON state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-way clutch utilizing the wedge action of a plurality of rolling members disposed between a shaft and an outer ring, and by eliminating contact between the rolling member and the shaft. The present invention relates to a one-way clutch having a so-called ON / OFF function capable of turning off a function as a direction clutch.

[0002]

2. Description of the Related Art In a one-way clutch which rotates idle in one direction of a shaft and locks against rotation in the other direction to prevent relative rotation with respect to an outer ring, a function as a one-way clutch is turned off. ON / OF that can be done
A clutch with an F function is known.

Hereinafter, an example of the configuration of a conventional one-way clutch having such an ON / OFF function will be described with reference to FIGS. FIG. 4 is an axially parallel sectional view, and FIG. 5 is an AA sectional view thereof. FIG. 6 is a front view (A) of the metal spring member 5 incorporated therein and FIG.
An arrow view (B) is shown, and FIG. 7 is an enlarged view (A) of a main part of FIG.
And a view (B) as viewed from an arrow B in a state where the outer ring thereof is seen through.

The outer race 1 has a plurality of cam surfaces 1a on its inner peripheral surface.
Are formed, and a plurality of rolling members (rollers) 3 which are held at regular intervals in a circumferential direction by a resin-made retainer 2 are incorporated on the inner peripheral side, and each rolling member 3 is provided inside thereof. It is in contact with the shaft 4 to be inserted, and is in contact with each cam surface 1 a of the outer race 1. A ring-shaped metal spring member 5 as shown in FIG. 6 is fitted in the retainer 2. The metal spring member 5 is configured such that the leaf spring portions 52 are integrally provided around the ring-shaped connecting portion 51 by the number of the rolling members 3, and the respective rolling members 3 are locked by the respective leaf spring portions 52, that is, In FIG. 7A, it is urged toward a narrow space side indicated by an arrow α.

In this example, the retainer 2 includes a main body 2a whose rotation with respect to the outer ring 1 is restricted, a ring-shaped movable part 2b which is separated from the main body 2a and can be relatively displaced in the circumferential direction. The movable portion 2b can be externally displaced in a direction indicated by β in FIG. 7A by operating a lever (not shown) or the like. The metal spring member 5 described above is fitted non-rotatably with respect to the main body 2a. By displacing the movable portion 2b in the direction of β, each rolling member 3 opposes the urging force of the leaf spring portion 52. 7A, the shaft 4 is displaced in the direction shown by a two-dot chain line in FIG.
Can be brought into a non-contact clutch function OFF state.

In the above configuration, for example, when the outer race 1 is fixed to a housing or the like, the moving portion 2b of the retainer 2
In the clutch function ON state shown by a solid line in FIG. 7A in which the shaft member 4 is rotated in the direction indicated by γ in FIG. 7A, the rolling member 3 has a large space. In order to move to the side, the shaft 4 idles, and when trying to rotate in the opposite direction, the rolling member 3 moves to the narrow space side, and by the wedge action of the cam surface 1a and the shaft 4 and the rolling member 3, , The rotation of the shaft 4 is stopped and the shaft 4 is locked.

On the other hand, in a clutch function OFF state in which each of the rolling members 3 is moved by rotating and displacing the moving portion 2b of the retainer 2 in the direction of β, the contact between each of the rolling members 3 and the shaft 4 is cut off. As a result, the shaft 4 can idle in any direction.

[0008]

By the way, in the one-way clutch having the ON / OFF function as described above,
In the clutch function OFF state, the rolling (idling) torque of the shaft 4 is basically 0 because the rolling member 3 is in a non-contact state with the shaft 4. However, when the clutch function is ON, since each rolling member 3 is urged toward the cam surface 1a by the leaf spring portion 52, a friction torque is generated when the shaft 4 idles. In order to reduce this torque as much as possible, the spring constant of the leaf spring portion 52 may be reduced.
When the spring constant of the leaf spring portion 52 is reduced, the urging force (repulsive force) of the spring when the clutch function is switched from the OFF state to the ON state is also reduced at the same time, so that the reliability of the lock when switched to the ON state is reduced. Problem arises.

The present invention has been made in view of such circumstances, and has a small idling torque of a shaft in a clutch function ON state and a large urging force on a rolling member in a clutch function OFF state to change from OFF to ON. An object of the present invention is to provide a one-way clutch that can improve the reliability of lock after switching.

[0010]

To achieve the above object, a one-way clutch according to the present invention comprises a plurality of rolling members,
An outer ring having cam surfaces formed at constant intervals in the circumferential direction on the inner peripheral surface, and a retainer that holds each rolling member at a constant interval in the circumferential direction such that a rolling member is arranged for each cam surface, A plurality of springs for biasing each rolling member in a direction of exerting a wedge action on the cam surface, and forcibly displacing each rolling member in a direction against the biasing force of the spring; The clutch function is ON / OFF, which makes the clutch function OFF in a non-contact state with the shaft inside it.
In the one-way clutch having the OFF means, each of the springs is a two-stage spring in which the spring constant in the amount of deflection in the clutch OFF state is increased compared to the spring constant in the amount of deflection in the clutch ON state. (Claim 1).

Here, in the present invention, as a preferred concrete configuration in which the spring for biasing each rolling member is a two-stage spring, each spring is formed by a bent portion formed at a position of a predetermined size from a base end. A leaf spring having a substantially V-shaped or substantially U-shaped cross section in which the distal end side thereof is in contact with a rolling member, and the length of the distal end side of the bent portion is shorter than the length of the base end side, and has a predetermined amount of bending. A configuration in which the base end side of the bent portion comes into contact with the stopper in the reached state (claim 2) can be adopted.

An object of the present invention is to achieve a desired object by increasing a spring constant of a spring for biasing each rolling member in a clutch function OFF state than in a clutch function ON state.

That is, in the one-way clutch having the ON / OFF function, the amount of deflection of the spring that biases each rolling member in the clutch function OFF state is larger than that in the clutch function ON state. Each spring is a two-stage spring whose spring constant increases when the amount of deflection reaches a predetermined amount, and the amount of deflection at which the spring constant changes is defined as the amount of deflection in the clutch function ON state and the amount of deflection in the OFF state. , The urging force of each rolling member in the clutch function ON state is reduced, and the clutch function is OFF.
It is possible to increase the urging force of each rolling member in the state.

According to a second aspect of the present invention, there is provided a one-way clutch capable of exhibiting the above-described operation with a simple structure in which a leaf spring for urging each rolling member is bent in a substantially V or U shape. Until the proximal end contacts the stopper, the relatively long proximal end mainly bends, and the relatively short distal end starts to flex after contacting the stopper, increasing the spring constant. . The amount of deflection of the spring in the clutch function ON state is set to the amount of deflection before the base end contacts the stopper, and the amount of deflection in the clutch function OFF state is set to the amount of deflection after the base end contacts the stopper. By doing so, the object can be achieved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a partial cross-sectional view in the direction perpendicular to the axis according to the embodiment of the present invention, and FIG.
FIG. 3 is a view as seen from the arrow B in a state where the outer ring 1 is seen through. FIG. 2A is a front view of the metal spring member 50 used in the embodiment of the present invention, and FIG. In this embodiment, a plurality of cam surfaces 1a
The outer ring 1 provided with the above, the retainer 2 composed of the main body 2a and the movable portion 2b, and the plurality of rolling members 3 have exactly the same configuration as that of the above-described conventional one-way clutch. Description is omitted.

As shown in FIG. 2, the number of leaf spring portions 502 equal to the number of ring-shaped connecting portions 501 and the number of rolling members 3 are fixed to the metal spring member 50 non-rotatably fitted into the main body portion 2a of the retainer 2. Are integrally formed by a metal plate having a uniform thickness, and each leaf spring portion 502 has a bent portion 502 a provided at a position of a predetermined dimension from a base end integrated with the connecting portion 501. It is folded back and is generally V-shaped or U-shaped as a whole. Further, the length of the base end side 502b across the bent portion 502a is longer than the length of the front end side 502c, and the front end side 502c abuts against the rolling member 3 to urge it.

In a state where the metal spring member 50 is fitted into the retainer 2, as shown in FIG.
Together with the rear (bending direction) in the wall of the body portion 2a of the retainer 2 is located, until the amount of deflection of the leaf spring 502 reaches [delta] ₁ that is set in advance, with respect to its wall The leaf spring portions 502 are not in contact with each other and are separated from each other at a predetermined angle.

Each leaf spring portion 50 having the above configuration
2, therefore, until the amount of deflection reaches [delta] _1, both deflected relatively long base side 502b sandwiching the bent portion 502a, after the amount of deflection exceeds [delta] _1, relatively short The distal end 502c bends, and its spring constant changes in two stages according to the amount of the deflection, and the deflection δ and the repulsive force W
Is as shown in the graph of FIG.

Then, as shown in FIGS. 1B and 3, the leaf spring portion 5 in the clutch ON state is provided.
Deflection amount of 02 [delta] ₀ is smaller than [delta] _1, also the amount of deflection [delta] ₂ of the plate spring portion 502 in the clutch function OFF state is set to be larger than [delta] _1.

According to the above embodiment of the present invention, FIG.
As shown by a solid line in FIG.
In the ON state of the clutch function, which is in close contact with the respective leaf spring portions 5 in a state where the spring constant is small.
02 urges the cam surface 1a side with a relatively small force, thereby reducing the idling torque of the shaft 4. Further, as shown by a two-dot chain line in FIG. 3, in the clutch function OFF state in which the movable portion 2b is rotationally displaced with respect to the main body portion 2a and the contact with the shaft 4 is cut off, each rolling member has a spring constant. In this state, the leaf spring portions 502 in the large state are biased to the cam surface 1a side by a large force, and the movable portion 2b of the retainer 2 is rotationally displaced in the opposite direction from the clutch function OFF state to release the clutch. When the function is switched to the ON state, each rolling member 3 surely moves to the cam surface 1a side, and there is no possibility that the reliability of the lock is impaired.

Here, in the above embodiment, the spring for biasing each rolling member 3 is a two-stage spring using a substantially V-shaped or substantially U-shaped leaf spring, but the present invention is not limited to this. Without being performed, any two-stage spring can be used as long as the spring constant increases when the amount of deflection reaches a predetermined amount. For example, two leaf springs are used, and the deflection of one leaf spring is used. It is a matter of course that another known method such as a method in which the other leaf spring comes into contact with the rolling member and starts to bend when the amount reaches a certain amount. However, when a substantially V-shaped or substantially U-shaped leaf spring as in the above embodiment is used, the object of the present invention can be achieved by bending a uniform metal plate. This is advantageous in terms of simplification and cost reduction.

In the above embodiment, the retainer 2 is provided with a rotatable movable portion 2b, and each rolling member 3 is moved in the circumferential direction with respect to the outer ring by the rotational displacement of the retainer 2. Although an example in which the function is turned off is given, the present invention is not limited to this. For example, a ring-shaped comb having teeth as many as the number of rolling members is inserted in the axial direction and rotated. Therefore, it goes without saying that a configuration in which each rolling member is moved can be adopted.

[0023]

As described above, according to the present invention, the spring for biasing the rolling member is a two-stage spring, and the clutch function is turned on.
In the state, each rolling member is urged under a small repulsive force based on a relatively small spring constant, and in the clutch function OFF state, a large stroke is applied under a relatively large spring constant based on a relatively large spring constant. Since each rolling member is urged, the idling torque of the shaft when the clutch function is ON is reduced, and the clutch function is turned OFF.
When switching from the state to the ON state, each rolling member can be reliably moved to the cam surface side of the outer race, and a highly reliable one-way clutch can be obtained. Here, the fact that the spring constant in the clutch function ON state can be reduced is as follows.
The influence of the dimensional variation of the components is reduced, which leads to a stable operation.

Further, by using a leaf spring bent in a substantially V-shape or a substantially U-shape as a two-stage spring, the above-described effects can be obtained at a low cost with a simple structure.

[Brief description of the drawings]

FIG. 1A is a partial cross-sectional view in a direction perpendicular to an axis according to an embodiment of the present invention, and FIG. 1B is a view as viewed from an arrow B in a state where the outer ring 1 is seen through;

FIG. 2A is a front view of a metal spring member 50 used in the embodiment of the present invention, and FIG.

FIG. 3 shows each leaf spring portion 5 used in the embodiment of the present invention.
12 is a graph showing the relationship between the amount of deflection δ of No. 02 and the repulsive force W.

FIG. 4 is an axially parallel sectional view showing a configuration example of a conventional one-way clutch with an ON / OFF function.

FIG. 5 is a sectional view taken along line AA of FIG. 4;

6 (A) is a front view of a metal spring member 5 incorporated in the one-way clutch with an ON / OFF function of FIG. 4, and FIG. 6 (B) is a view on arrow B thereof. .

7 (A) is an enlarged view of a main part of FIG. 5, and FIG. 7 (B) is a view on arrow B in a state where the outer ring 1 is seen through.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer ring 1a Cam surface 2 Cage 2a Main part 2b Movable part 3 Rolling member 4 Axis 50 Metal spring member 501 Connecting part 502 Plate spring part 502a Bent part 502b Base end 502c Distal end

Claims (2)

[Claims] 1. A plurality of rolling members, an outer ring having cam surfaces formed on the inner peripheral surface at regular intervals in a circumferential direction, and each rolling member is circumferentially arranged such that the rolling members are arranged on the respective cam surfaces. A retainer that holds the direction at constant intervals, and a plurality of springs that urge each rolling member in a direction to exert a wedge action on the cam surface, and a direction in which each rolling member opposes the urging force of the spring. The rolling function is forcibly displaced so that the rolling member and the shaft inside the rolling member do not contact each other.
In the one-way clutch having the clutch function ON / OFF means in the F state, each of the above-mentioned springs has a spring constant in the amount of bending in the clutch OFF state which is larger than the spring constant in the amount of bending in the clutch ON state. A one-way clutch characterized by a two-stage spring. 2. A leaf spring having a substantially V-shaped or U-shaped cross-section, wherein each of the springs is folded at a bent portion formed at a position of a predetermined size from a base end, and a leading end thereof contacts a rolling member. The length of the distal end side of the bent portion is shorter than the length of the proximal end side, and the base end side of the bent portion is configured to contact the stopper in a state where a predetermined amount of bending is reached. The one-way clutch according to claim 1.