JPH0140351Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a clutch/brake device used in power lawn mowers and the like.

Conventionally, this type of clutch/brake device
An apparatus shown in the partially cutaway front view of FIG. 1 has been developed (see Japanese Unexamined Patent Publication No. 55731/1983).

This device has an operation panel 4 supported concentrically via a bearing 3 on an output shaft 2 of a rotating machine 1 (for example, a small engine) serving as a drive source. This operation panel 4 can be rotated at a predetermined small angle in the circumferential direction,
A lever 5 for applying external force is formed in a portion.

An input hub 6 is fixed onto the output shaft 2, and an output hub 8 is concentrically supported on a boss portion 6A of the input hub 6 via a bearing 7.

The output hub 8 is a member for fixing a lawn mowing cutter (not shown), and has a friction plate 9 fitted in a spline shape to the upper end of the boss portion 8A.

The friction plate 9 includes a flange portion 6 of the input hub 6.
A friction piece 10 whose half part closer to the inner periphery faces B is fixed to the outer periphery part of the upper surface, while always receiving the elastic pressing force of the compression coil spring 11 provided between the output hub 8 and the input It has a tendency to come into pressure contact with the flange portion 6B of the hub 6.

The outer half of the friction piece 10 is attached to the back surface of a brake annular member 14 that can move forward and backward only in the axial direction using a collar 13 fitted to a fixing bolt 12 screwed into the machine frame of the rotating machine 1 as a guide. Frictional engagement is possible.

Usually, three fixing bolts 12 are used, arranged at equal angles of 120 degrees.

The brake annular member 14 and the operation panel 4 are opposed to each other via clutch balls 15 at a plurality of positions.

The clutch ball 15 is usually a bearing ball, and is fitted into a groove 16 on the operation panel 4 side and a groove 17 on the brake annular member 14 side.

The grooves 16 and 17 each have an inclined bottom that becomes shallower toward one end, and the inclined directions of the bottoms are aligned with each other.
The left and right opposite sides are in the direction of being shallower.

In the device shown in FIG. 1, two operations of clutch engagement or clutch disengagement and braking can be obtained by rotating the operating panel 4 to the right or left extreme position.

That is, when the operation panel 4 is rotated so that the clutch ball 15 faces the shallow part of the grooves 16 and 17, the brake annular member 14 moves away from the operation panel 4 and becomes fixed to the friction plate 9. A certain friction piece 10 is pushed and this friction piece 10 is separated from the input hub 6. When the friction plate 10 separates from the input hub 6, the torque transmission to the output hub 8 to which the friction plate 9 is fitted in a spline shape is interrupted, and at the same time, the compression coil spring 11
The friction plate 9, which is being pushed, comes into frictional engagement via the friction piece 10 with the braking annular member 14, which does not rotate, so that the rotation of the output hub 8 is instantaneously stopped.

When the operation panel 4 is rotated in the opposite direction, that is, when the clutch ball 15 faces the deepest part of the grooves 16 and 17, the downward force on the brake annular member 14 is removed, and the clutch ball 15 is subjected to the pressing force of the compression coil spring 11. As the friction plate 9 is pushed upward, the friction piece 10 frictionally engages with the input hub 6, and the output shaft 2 and output hub 8 rotate together.

By the way, in the conventional clutch/brake device,
Since the brake annular member 14 has a structure in which the entire circumferential surface of the side surface opposite to the side surface on which the groove 17 is formed serves as a friction surface for the friction piece 10, the thickness of the brake annular member 14 increases, resulting in an increase in weight. Therefore,
This brake annular member 14 in the clutched state
frictionally engages with the friction piece 10 due to its own weight, and the friction piece 1
0 is abnormally worn. Furthermore, even if the return spring of the brake annular member 14 is incorporated, the brake annular member 1
4 is loosely fitted into the fixing bolt 12 and may frictionally engage with the friction piece 10 while receiving vibrations from the rotating machine 1, and the impact of the braking annular member 14 due to this frictional engagement is large on the fixing bolt 12 and the clutch ball 15. There was a problem in that the durability of the device was deteriorated.

The present invention was devised in view of the above points, and an object of the present invention is to provide a clutch/brake device with improved durability. In order to achieve this purpose, the present invention includes an operation panel that is freely pivoted to the output shaft of a rotating machine that serves as a drive source and can be rotated by a predetermined small angle, and a clutch ball is connected to this operation panel. The rotary machine has a fixing bolt threaded onto the machine frame of the rotating machine so that it can move forward and backward only in the axial direction, and on the side opposite to the operation panel there is an overhang that is discontinuous in the circumferential direction and a flat area between the overhang. A braking annular member having a protruding bottom portion of a groove into which the clutch ball is inserted, and a flange portion extending in a radial direction inside the braking annular member, the braking annular member being rotatable integrally with the output shaft. an input hub that is mounted on a shaft, a friction plate that is in frictional engagement with the flange portion of the input hub on the inner circumference side, and a friction plate on which the overhanging portion of the braking annular member is frictionally engaged with the outer circumference side; an output hub that is supported so as to move forward and backward and is rotatably mounted on the output shaft; and a compression mechanism that is interposed between the output hub and the friction plate and that presses the friction plate against the flange of the input hub. It is characterized by being equipped with a coil spring.

In a clutch/brake device with such a structure, the friction plate on the output hub is frictionally engaged with the flange of the input hub on the output shaft by the pressing force of the compression coil spring, so that the rotation of the rotating machine is caused by the rotation of the output hub. is transmitted to. In this state, when the operation panel is rotated to move the brake annular member forward via the clutch ball, the protruding part of the brake annular member frictionally engages with the friction plate and resists the pressing force of the compression coil spring. Since the friction plate is separated from the flange portion of the input hub, the rotation of the rotating machine to the output hub is immediately cut off and the output hub is stopped.

Next, the apparatus of this invention will be explained by way of examples with reference to the drawings.

FIG. 2 shows an embodiment of the device according to the present invention in a partially longitudinal front view, and FIG. 3 shows a partially omitted bottom view. The device of this invention is basically the same as the device explained in Fig. 1, but the structure of the braking annular member has been greatly improved to achieve the purpose. The same reference numerals are given to the same members, and the structure thereof is referred to the previous explanation and will not be explained repeatedly. As shown in the drawings, both the operation panel 4 and the brake annular member 14' are press-formed products made of thin plate materials.

The brake ring 14' is shown in plan view in FIG.
As shown in the longitudinal cross-sectional view in FIG. 5, the portion along the outer periphery of the three equiangular portions of the annular plate is shaved off parallel to the tangent line to form a straight edge 14'a, while making contact with the friction plate 9. As three overhangs 14'A,
A portion between the inner circumferential edge 14'b and a cut 18 parallel to the inner circumferential edge is formed to bulge downward by press working.

Further, a groove 17 is formed in the flat part 14'B between the three projecting parts 14'A. moreover,
The hole 19 through which the fixing bolt 12 is inserted is inserted into the overhang part 1.
A flat portion 14'B is bored on the outer side of 4'A.

In addition, in the device of this invention, the braking annular member 1
Compression coil spring 2 that actively raises 4'
0 is installed concentrically with each fixing bolt 12, and a tension spring 21 is installed that pulls the operation panel 4 in the direction of clutch disengagement and brake engagement.

Although no friction piece is attached to the friction plate 9 in this embodiment, a friction piece 10 similar to that shown in FIG. 1 may be attached if necessary. Furthermore, although the compression coil spring 20 is incorporated, it may not be incorporated.

The output hub 8' shown in a plan view in FIG. 6 and in a longitudinal cross-sectional view in FIG. Cuts 22 are intermittently cut in the circumferential direction at predetermined positions near the upper end of portion 8'A, and at the same time, the portion above the cuts 22 is pushed and bent radially inward to form an uneven wall 23. .

As the friction plate 9' to be spline-fitted to the output hub 8', the one shown in a plan view in FIG. 8 and in a vertical cross-sectional view in FIG. 9 is suitable.

This friction plate 9' has an inner peripheral portion formed with a concave and convex inner edge 24 that engages with the concave and convex wall 23 of the output hub 8'.

In the clutch/brake device constructed in this way, the friction plate 9 on the output hub 8 is frictionally engaged with the flange portion 6B of the input hub 6 on the output shaft 2 due to the pressing force of the compression coil spring 11, so that rotation is prevented. The rotation of the machine 1 is transmitted to the output hub 8. In this state, when the operation panel 4 is rotated to move the brake annular member 14' forward via the clutch ball 15, the protrusion 14'A of the brake annular member 14' frictionally engages with the friction plate 9. Since the friction plate 9 is separated from the flange portion 6B of the input hub 6 against the pressing force of the compression coil spring 11, the rotation of the rotating machine 1 to the output hub 8 is immediately cut off and the output hub 8 is stopped. .

As is clear from the above explanation, the clutch/brake device of this invention has a braking annular member that is recessed into a circumferentially discontinuous projecting portion on the side opposite to the operation panel and a flat portion between the projecting portions. Since the bottom of the groove into which the clutch ball is fitted has a protruding shape, there is no need to use a plate material with a wall thickness greater than the depth of the deepest part of the groove into which the clutch ball is fitted, and the braking annular member is Lighter weight can be achieved.

Therefore, the fixing bolt and clutch ball are less likely to be damaged by the impact of the protrusion of the brake annular member that frictionally engages with the friction plate due to its own weight, and the durability of the device can be improved.

In addition, in this invention, only the planar side surface of the overhanging part of the braking annular member is used as a friction engagement surface with the friction plate, and the sloped surface of the bottom of the groove into which the clutch ball is inserted is used as a non-friction engagement surface with respect to the friction plate. Therefore, no frictional engagement force is applied directly to the bottom of the groove, thereby preventing the groove from deforming.

Furthermore, the braking annular member can be made of a pressed product made of a thin plate material, and the manufacturing cost can be reduced, which has excellent practical effects.

[Brief explanation of the drawing]

Fig. 1 is a front view in half longitudinal section showing a conventional clutch/brake device, Fig. 2 is a front view in half longitudinal section showing an embodiment of the device of this invention, and Fig. 3 is partially omitted. The bottom view, FIG. 4, and FIG. 5 show the braking annular member, FIG. 4 is a plan view, and FIG. 5 is a longitudinal sectional view.
6 and 7 show modified examples of the output hub,
The figure is a plan view, FIG. 7 is a vertical sectional view, FIGS. 8 and 9 show modified examples of the friction plate,
The figure is a longitudinal sectional view. In the drawings, 1... rotating machine, 2... output shaft, 4...
Operation panel, 6...Input hub, 8, 8'...Output hub, 9,
9'...Friction plate, 14, 14'...Brake annular member, 1
4'A... overhanging part, 14'B... flat part, 17... groove.

Claims (1)

[Scope of utility model registration request] An operation panel 4 is mounted on the output shaft 2 of a rotating machine 1 serving as a drive source so as to be able to rotate by changing a predetermined small angle, and a machine frame of the rotating machine 1 faces the operation panel 4 via a clutch ball 15 It can move forward and backward only in the axial direction by means of a fixing bolt 12 screwed into the panel, and a protrusion 14'A that is discontinuous in the circumferential direction on the side opposite to the operation panel and a recess in the flat part between the protrusion 14'A are provided. A brake annular member 14' having a protruding bottom portion of the groove 17 into which the clutch ball 15 is fitted, and a flange portion 6 extending radially inside the brake annular member 14'.
an input hub 6 which is configured as B and is integrally rotatably mounted on the output shaft 2; and a flange portion 6B of the input hub 6 and the protruding portion 14 of the braking annular member 14' whose inner periphery is frictionally engaged. A friction plate 9 that is frictionally engaged with the outer circumferential portion of A, an output hub 8 that supports this friction plate 9 so that it can freely move forward and backward only in the axial direction, and is rotatably mounted on the output shaft 2, and this output hub. 8 and the friction plate 9, and a compression coil spring 11 for pressing the friction plate 9 against the flange portion 6B of the input hub 6.