JPH0144941B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wire elongation absorption mechanism (hereinafter simply referred to as absorption mechanism). More specifically, the present invention relates to an absorption mechanism that has been improved to prevent tooth skipping in an absorption mechanism that utilizes the unidirectional interlocking properties of ratchet teeth.

Conventionally, in remote control systems that use flexible wires as power transmission means,
Some wires incorporate an absorption mechanism to absorb the permanent elongation that occurs in the wire. As such an absorbing mechanism, a mechanism has been proposed that is incorporated into a wire driving device as shown in FIG. 5, and automatically absorbs the elongation of the wire when the wire 51 is driven. Such a wire drive device is
Both ends of the wire 51 routed in a closed loop are secured to the surface thereof, one end 52 of the wire 51 is wound up, and the other end 53 is unwound, thereby causing the loop of the wire 51 to be directed in either direction. It has a drive pulley 54 for circulation. Drive pulley 5
4 is divided into a first pulley 55 and a second pulley 56, and the first pulley 55 and second pulley 56 can rotate relative to each other only in the direction to shorten the loop of the wire, and such relative rotation This can absorb the elongation of the wire. In order to rotate only in such a specific direction, the first pulley 55
A first ratchet tooth 57 and a second ratchet tooth 58 are carved on the side surfaces adjacent to each other of the first pulley 55 and the second pulley 56, respectively.
It is allowed to move in the axial direction relative to the pulley 56,
Further, a wave washer 59 or the like is employed as an elastic means for pressing the first pulley 55 and the second pulley 56 against each other.

An absorption mechanism having such a configuration is, for example, a first
The loop of wire 51 can be driven in either direction by rotating shaft 60, which is coupled to pulley 55 in a torque transmitting manner, in the direction of arrow A or arrow B. Furthermore, when the shaft 60 is rotated in the direction in which the ratchet teeth 57, 58 idle (in the direction of arrow B in FIG. 5), the elongation of the wire can be absorbed.

However, if the load on the wire 51 driven by the drive pulley 54, such as the sliding resistance in the driven device, becomes large, the ratchet teeth may become loose even when rotated in the direction of arrow A, which is the original meshing direction. A tooth skipping phenomenon may occur in which the gears 57 and 58 run idly. This tooth skipping phenomenon causes the wire, which has absorbed the elongation and recovered its tension, to become loose again.
Further, when the tooth skipping phenomenon occurs repeatedly, the tooth tips of the ratchet teeth 57 and 58 are worn, making the tooth skipping phenomenon even more likely to occur. Therefore, there is a problem in that not only does the absorption mechanism fail to fulfill its original role, but it also causes the wire to become loose.

On the other hand, in recent years, there has been a trend to reduce the tooth profile of the ratchet teeth 57, 58 in order to reliably absorb even the slightest elongation of the wire, which makes the tooth skipping phenomenon more likely to occur. Therefore, appropriate measures to prevent the tooth skipping phenomenon are increasingly desired these days.

The inventors of the present invention have conducted extensive research in order to meet the above-mentioned demands, and have developed the following: a casing, a shaft rotatably provided within the casing, a flange fixed to the shaft, and the flange. The casing is rotatably and axially movably housed adjacent to the casing, and is coupled to the flange so as to transmit torque so as to have play in the rotational direction. a first pulley having one ratchet tooth; rotatably and axially movably housed within the casing adjacent to the first pulley;
a second pulley having second ratchet teeth that can mesh with the first ratchet teeth; an elastic means for biasing the second pulley toward the first pulley; a first pulley formed on an end surface of the flange; a cam protrusion; and a second cam protrusion formed on a side surface adjacent to the flange of the first pulley so as to cooperate with the first cam protrusion; a cam means in which the protrusions ride on each other so as to separate the flange and the first pulley when the ratchet teeth are rotated in the direction in which they mesh with each other, and the protrusions are released from riding on each other when rotated in the idling direction; When employing a wire elongation absorption mechanism that has both ends locked to the outer peripheries of the first pulley and the second pulley, and power transmission wires that are wound in opposite directions to each other, it is easy to The present invention was completed based on the discovery of the completely new fact that the above-mentioned tooth skipping phenomenon can be significantly reduced by a configuration of the present invention.

Next, the absorption mechanism of the present invention will be explained with reference to the drawings.

Fig. 1 is a front view showing one embodiment of the absorption mechanism of the present invention (however, the housing is omitted), Fig. 2 is a sectional view taken along the line X-X of Fig. 1, and Figs. 3 and 4 are 2A and 2B are enlarged cross-sectional views taken along the Y-Y line in FIG. 1, respectively.

1 and 2, 1 is a housing, and a cylindrical casing 2 with a bottom is fixed to the housing 1. As shown in FIG. A shaft 3 is rotatably provided inside the casing 2. One end 3 of shaft 3
a is made to protrude outward from the housing 1 in order to be coupled with, for example, a crank type handle 3b. A cylindrical flange 4 with a bottom is attached to the shaft 3 so as to be concentric with the shaft 3, and is fixed by, for example, welding.

A first pulley 5 and a second pulley 6 are fitted on the outer periphery of the shaft 3 adjacent to the flange 4 so as to be rotatable and movable in the axial direction in that order.

A wave washer 8 is inserted between the second pulley 6 and the casing 2.
The pulley 6 and the first pulley 5 are indicated by arrow C in FIG.
It is constantly being pushed in the direction.

First ratchet teeth 9 and second ratchet teeth 10 are formed on adjacent side surfaces of the first pulley 5 and the second pulley 6, respectively. The first ratchet teeth 9 and the second ratchet teeth 10 mesh with each other when the first pulley 5 is rotated in the direction of arrow A, and idle when the first pulley 5 is rotated in the direction of arrow B.

A fan-shaped notch 11 is formed along the periphery of the flange 4. A protrusion 12 that can be engaged with the notch 11 is provided on the side surface of the first pulley 5 adjacent to the flange 4 . Notch part 1
The opening angle of projection 12 is larger than that of projection 12, so there is some play in the rotational direction in the engagement between the two.

The fan-shaped notch 11 and the fan-shaped protrusion 12 shown in FIG. (Means for transmitting torque to pulley 1 but not transmitting torque in the opposite direction)
It is possible to adopt the components that constitute .

Note that the connection between the flange 4 and the first pulley 5 in the absorption mechanism of the present invention is not limited to the combination of the notch 11 and the protrusion 12, but may be a combination of a pin that can be engaged with an arcuate long hole, etc. , any torque transmitting means having play in the rotational direction can be used.

As shown in detail in FIGS. 3 and 4,
A first cam protrusion 13 is provided on the end surface of the flange 4 adjacent to the first pulley 5. 1st pulley 5
A second cam projection 14 is provided so as to be continuous with the projection 12. The first cam projection 13 and the second cam projection 14 have tapered surfaces 15, 16 extending in the circumferential direction so as to ride on each other when the flange 4 is rotated in the direction in which the ratchet teeth 9, 10 mesh, that is, in the direction of arrow A. They each have The first cam projection 13 and the second cam projection 14 constitute a cam means.

In addition, as shown in FIGS. 1 and 2, the first pulley 5
Both ends of a wire 51 are locked and wound around the second pulley 6, similar to a conventional absorption mechanism (for example, the one shown in FIG. 5). Figure 2 1
7 is a conventionally known balance spring.

Next, the operation of the absorption mechanism constructed as described above will be explained.

When the shaft 3 is rotated in the direction of the arrow A in FIG. 2, the tapered surfaces 15 of the cam projections 13 and 14 are connected to each other before the notch 11 of the flange 4 and the projection 12 engage with each other, as shown in FIGS. 3 and 4. , 16 try to climb onto each other. Therefore, the first pulley 5
An urging force in the direction of arrow D is applied to . As a result, the first pulley 5 and the second pulley 6 move in the direction of the arrow D against the urging force of the wave washer 8 in the direction of the arrow C. This movement is performed while the flange 4 is rotated relative to the first pulley 5 by the amount of play.

When the shaft 3 is further rotated, the notch 11 and the protrusion 12 engage with each other in a state where the elongation absorption clearance L becomes smaller, and the first pulley 5 is rotated in the direction of arrow A.

As a result, the second pulley 6 is hardly able to move in the axial direction, and the tooth skipping phenomenon is almost certainly prevented. In that case, the cam projection 13,
14 or the distance of movement of the pulleys 5 and 6 caused by the engagement of the cam projections 13 and 14 is the first
It is preferable to make the length larger than the elongation absorption clearance L shown in the figure minus the height H of the ratchet teeth 9, 10. Thereby, the tooth skipping phenomenon can be reliably prevented.

Further, when the cam projections 13 and 14 are riding on each other, the axial pressing force between the ratchet teeth 9 and 10 is increased by an amount corresponding to the amount of deflection of the wave washer 8. Therefore, the tooth skipping phenomenon becomes even less likely to occur.

The shape of the cam means in the absorption mechanism of the present invention is not limited to that shown in FIGS. 3 and 4; for example, the cams on either side may be grooves with tapered surfaces. Further, instead of a tapered surface, it may be an arcuate surface or other convex or concave surface.
That is, the cam means in the present invention may be any means that biases the first pulley 5 toward the second pulley 6 when the flange 4 is rotated in the direction in which the ratchet teeth 9 and 10 mesh.

In the embodiment of the absorption mechanism shown in FIG. 1, only one set of protrusions 13 and 14 as cam means is provided, but when 2 to 6 sets are arranged at equal intervals in the circumferential direction, the cam protrusions This is preferable because when the first pulley 5 and the flange 4 are separated by the runners 13 and 14 riding on each other, the urging force for separation can be made almost uniform in the circumferential direction.

Although the positions of the cam projections 13 and 14 are not particularly limited, when the projections 12 and the notch 11 are placed in a position where they come into contact with each other before they completely ride on each other, the flange 4 may be This is preferable because it is easy to rotate the cam projections 13 and 14 in the B direction to disengage the cam projections 13 and 14 from each other.

In the embodiment of the absorption mechanism shown in FIG. 2, a shaft 3 is stretched between the housing 1 and the casing 2, and a first pulley 5 and a second pulley 6 are respectively provided on the shaft 3. However, the absorption mechanism of the present invention is not limited to such cases. Each pulley 5, 6 is installed in the casing 2 rotatably and axially so as to be in direct sliding contact with the inner surface of the housing 1 or the casing 2, or indirectly by a fixed shaft protruding from the casing 2, etc. It suffices if it is provided so that it can be moved.

As described above, the wire elongation absorbing mechanism of the present invention can significantly reduce the tooth skipping phenomenon with a simple structure, and its practical value is extremely large.

[Brief explanation of drawings]

FIG. 1 is a front view showing one embodiment of the wire elongation absorption mechanism of the present invention (however, the housing is omitted), FIG. 2 is a sectional view taken along the line X-X in FIG. 1, FIG. 4 is an enlarged sectional view taken along the Y-Y line in FIG. 1, and FIG. 5 is a vertical sectional view showing an example of a conventional wire elongation absorption mechanism. (Main symbols in the drawing), 2: Casing, 3: Shaft,
4: Flange, 5: First pulley, 6: Second pulley, 8: Wave washer, 9: First ratchet tooth, 10: Second ratchet tooth, 11: Notch, 12: Projection, 13: First cam projection , 14: second cam projection, 15, 16: tapered surface, 51: wire, L: elongation absorption clearance, H: height of ratchet tooth.

Claims (1)

[Scope of Claims] 1. A casing, a shaft rotatably provided in the casing, a flange fixed to the shaft, and a shaft rotatably provided in the casing adjacent to the flange in the axial direction. a first pulley movably housed in the flange, coupled to the flange so as to transmit torque so as to have play in a rotational direction, and having first ratchet teeth on a side surface opposite to the flange; rotatably and axially movably accommodated in the casing adjacent to the pulley;
a second pulley having second ratchet teeth that can mesh with the first ratchet teeth; an elastic means for biasing the second pulley toward the first pulley; and a first pulley formed on the end surface of the flange. It consists of a cam protrusion and a second cam protrusion formed on a side surface adjacent to the flange of the first pulley so as to cooperate with the first cam protrusion, and the flange is arranged within a range of play with respect to the first pulley. a cam means in which the protrusions ride on each other so as to separate the flange and the first pulley when rotated in the direction in which the ratchet teeth mesh with each other; and the protrusions are released from riding on each other when rotated in the idling direction; A wire elongation absorption mechanism comprising a power transmission wire whose both ends are locked to the outer peripheries of a first pulley and a second pulley, and which are wound in opposite directions. 2. The wire elongation according to claim 1, wherein the first cam projection has a tapered surface extending in the circumferential direction of the flange, and the second cam projection has a tapered surface extending in the circumferential direction of the first pulley. Absorption mechanism.