JPH0140352Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is equipped with a ball-type cam actuation mechanism having a cam ball, and the clutch and brake are operated via this ball-type cam actuation mechanism by rotating the operation plate at a predetermined angle. This invention relates to a clutch/brake device that switches operation, particularly to improvements in unitizing a ball-type cam operating mechanism.

[Prior art] Conventionally, clutch and brake devices such as power lawn mowers have used a ball-type cam operating mechanism to switch between clutch and brake, but lawn mower manufacturers have supplied the clutch and brake devices as individual parts. The problem is that the number of assembly steps increases, resulting in poor work efficiency and inability to improve productivity. Therefore, in order to improve these problems,
A clutch/brake device proposed as a unit is described in Japanese Utility Model Application No. 58-49037.

The clutch/brake device described here is
The flange part is clamped and fixed in the center hole of a mounting plate bolted to the frame of a rotating machine such as a small engine of a power lawn mower, between the side of the periphery of the center hole of this mounting plate and the machine frame of the rotating machine. The rotary machine has a cylindrical boss member, and the output shaft of the rotating machine projects from the inside of the boss member. A guide groove in the axial direction is formed in the cylindrical boss member, and a protrusion is fitted into this guide groove to restrict relative rotation.The brake ring plate has a groove bent outward in the axial direction. A convex portion serving as a brake torque transmitting portion is provided on the mounting plate, and a flange portion bent in the axial direction so as to face the convex portion radially outwardly is provided on the mounting plate, and the convex portion restricts only relative rotation. A recess is formed into which the recess is fitted. The brake ring plate is fitted into the guide groove on the inside and into the recess on the outside, so that it can move forward and backward only in the axial direction, and the brake torque is absorbed by the machine frame of the rotating machine via the mounting plate. It is a structure. On the other hand, a groove for the cam ball is formed in the brake ring plate, and an operation plate having a groove formed with a groove with an inclined bottom facing in the opposite direction in the circumferential direction from the inclined bottom of this groove is attached to the outer periphery of the boss member. They are fitted and prevented from coming off, allowing relative rotation. Further, a compression coil spring is interposed between the mounting plate and the brake ring plate, and the brake ring plate moves forward due to the pressing force of the compression coil spring, and resists the pressing force of the compression coil spring. When the operation plate is rotated, the brake ring plate is moved backward by the cam action of the cam ball.

Therefore, in a clutch/brake device having such a ball-type cam operating mechanism, the output hub, which is rotatably mounted to the output shaft via a bearing, is moved forward or backward by the rotation of the operating plate. The upper friction plate is separated from the flange of the input hub that rotates integrally with the output shaft against the spring force of the compression coil spring interposed between the output hub and the friction plate, and the clutch is released. A brake that brakes the output hub is operated by the frictional engagement between the brake ring plate and the friction plate. If the operating plate is rotated from this state to move the brake ring plate backward, the frictional engagement between the brake ring plate and the friction plate is switched to the frictional engagement between the friction plate and the flange portion of the input hub. Activate the clutch.

As described above, in the conventional clutch/brake device, the cylindrical boss member has a flange portion that comes into contact with the side surface of the periphery of the center hole of the mounting plate.
By fitting each brake ring plate and operation plate to prevent them from coming off, the pressing force of the compression coil spring that obtains brake torque can be reduced by the flange of the boss member or a retaining ring such as a snap spring fitted to this boss member. The ball-type cam operating mechanism with this structure can be assembled by inserting the output shaft of the rotating machine inside the boss member and bolting the mounting plate to the frame of the rotating machine. It is possible. Therefore, the efficiency of the assembly work can be improved and productivity can be improved.

[Problem to be solved by the invention] By the way, in such a unitized ball type cam actuation mechanism, a flange portion bent in the axial direction is formed on the outside of the mounting plate, and a recessed portion is formed in this flange portion. At the same time, by fitting the convex part bent in the axial direction on the outside of the brake ring plate into this recess, the brake torque of the brake ring plate is transferred to the mounting plate bolted to the machine frame of the rotating machine. Since a absorbing structure was adopted, the diameter of the punched plate material used for each of the mounting plates and the brake ring plate was increased by press processing, resulting in an increase in material costs. In addition, it is possible to weld a highly rigid metal, etc. to the flange of the mounting plate, bend both ends of the flange in the circumferential direction, or even form the mounting plate itself with a thick wall. Since this requires a machining process to form a recess in the flange, there is a problem in that the productivity of parts is poor and it is not possible to provide an inexpensive clutch/brake device.

The object of the present invention is to provide a clutch/brake device having a unitized ball type cam mechanism at low cost.

[Means for Solving the Problems] In order to achieve such an object, the present invention provides a mounting plate having a cylindrical boss portion into which the output shaft of a rotating machine is inserted, and a boss portion of the mounting plate. A brake ring plate is fitted to the brake ring plate so as to be freely advanced and retractable only in the axial direction, and the brake ring plate has a groove at a sloped bottom opposite in the circumferential direction from the groove at the sloped bottom formed in the brake ring plate, and the boss portion of the mounting plate a cam ball that is held between the opposing grooves of the brake ring plate and the operation plate, and a cam ball that is radially outward from the cam ball and that is connected to the mounting plate and the brake ring. a compression coil spring interposed between the brake ring plate and the mounting plate, and a ball-type cam operating mechanism in which the braking ring plate is prevented from coming off from the boss portion of the mounting plate against the pressing force of the compression coil spring. In the clutch/brake device, the mounting plate is provided with cut-and-raised portions bent in the axial direction and convex portions that protrude alternately in the circumferential direction, and the brake ring plate has a through-hole in which the cut-and-raised portions are engaged. By forming a hole and a convex portion facing the convex portion in the axial direction, the engagement of the cut and raised portion with the through hole restricts relative rotation of the brake ring plate with respect to the mounting plate, and The ball type cam mechanism is characterized in that the ball-type cam mechanism includes a compression coil spring whose both ends are fitted around each of the convex portions and interposed between the mounting plate and the brake ring plate.

[Operation] In the clutch/brake device with this structure, when the operating plate is rotated against the pressing force of the compression coil spring, the brake ring plate retreats due to the cam action of the cam ball, and the operating plate moves in the opposite direction. When the brake ring plate is rotated, the brake ring plate moves forward due to the cam action of the cam ball and the pressing force of the compression coil spring. In addition, the relative rotation of the brake ring plate is restricted by the cut-and-raised part of the mounting plate, and the compression coil spring, which receives the vibration of the brake ring plate, is prevented from falling off by the convex parts formed on each operation plate and the brake ring plate. be done.

[Example] Next, the apparatus of this invention will be described by way of an example with reference to the drawings.

FIG. 1 shows an embodiment of the device according to the invention in a longitudinal sectional side view, and FIG. 2 shows a front view of the mounting plate. As shown in the drawings, in the device of this invention, a clutch brake device and a ball type cam mechanism are integrated into a unit, and the device is mounted on an output shaft 2 of a rotating machine 1 such as a small engine of a power lawn mower.

The clutch brake mechanism includes a boss portion 3B of an input hub 3 having a radially extending disk-shaped flange portion 3A, an annular member having an L-shaped cross section, a cylindrical portion 5A, and a disk portion 5B. An output hub 5 is supported via a bearing 4. An axial groove is formed at the tip of the cylindrical portion 5A of the output hub 5, and a disc-shaped friction plate 6 with a protrusion fitted into the groove formed on the periphery of the center hole is attached to the output hub 5. It is supported so that it can move back and forth in the axial direction while relative rotation is restricted. The inner diameter side surface of the friction piece 7 fixed to the friction plate 6 faces the outer diameter side surface of the flange portion 3A of the input hub 3 so as to be able to freely engage with the friction plate 6. The structure is such that the friction piece 7 and the flange part 3A of the input hub 3 are frictionally engaged by the pressing force of the compression coil spring 13 interposed on the outside of the cylindrical part 5A of the output hub 5 between the disc part 5B and the flange part 3A of the input hub 3. ing.

Next, the ball-type cam actuating mechanism is formed by forming cut-and-raised portions 16 and convex portions 21 alternately in the circumferential direction on the disc-shaped mounting plate 8 on which the cylindrical boss portion 8A is formed. , the boss portion 8A of this mounting plate 8
A through hole 15 into which the cut and raised portion 16 is inserted and a projection 22 facing the projection 21 in the axial direction are formed alternately in the circumferential direction, and an inclined surface into which the cam ball 11 is fitted is formed. A brake ring plate 1 is formed with a flange portion 12A that frictionally engages with the groove 24 at the bottom and the outer diameter side of the friction piece 7 of the clutch brake mechanism.
2 is loosely fitted. Then, the cut and raised portion 16 of the mounting plate 8 is engaged in the through hole 15 of the brake ring plate 12, and the space between the peripheral side surface of the convex portion 21 of the mounting plate 8 and the peripheral side surface of the convex portion 22 of the brake ring plate 12 is engaged. An operation plate 10 is supported by a boss portion 8A of the mounting plate 8 via a bearing 9 so as to be freely rotatable, with a compression coil spring 14 interposed therebetween. Further, a groove 23 is formed in this operation plate 10, and the groove 23 has a sloped bottom facing in the opposite direction in the circumferential direction to the sloped bottom of the groove 24 formed in the brake ring plate 12. 11 is clamped and can freely roll. Furthermore, by securing the bearing 9 to the boss portion 8A of the mounting plate 8 with a snap spring, each braking ring plate 12 and the operation plate 10 can resist the pressing force of the compression coil spring 14 against the mounting plate 8. is prevented from falling out.
Reference numeral 10A is a lever riveted to the operating plate 10 and extending outward from the through hole 15 of the brake ring plate 12, and the operating plate 10 is externally operated via this lever 10A.

As described above, the clutch brake mechanism assembled and unitized on the input hub 3 and the ball type cam operating mechanism assembled and unitized on the mounting plate 8 are as follows. It is assembled to the machine frame of the rotating machine 1 by tightening bolts 26 through the through holes 25 of the mounting plate 8. The clutch brake mechanism also includes fitting the input hub 3 to the output shaft 2 via the key 17 and abutting it against the stepped portion of the output shaft 2.
By tightening the bolt 20 onto the output shaft 2 through the input hub 3 and the inner ring of the bearing 4, the input hub 3 and the inner ring of the bearing 4 are prevented from coming off and assembled. A flange portion 12A formed on the brake ring plate 12 of the ball type cam actuating mechanism outside the flange portion 3A of the input hub 3 of the clutch brake mechanism has a structure that can freely move back and forth in the axial direction.

In the embodiment of the present invention, the bearing 9 is incorporated into the ball-type cam operating mechanism, but the outer peripheral surface of the boss portion 8A of the mounting plate 8 is directly connected to the bearing surface of the operating plate 10 as in the conventional ball-type cam operating mechanism. It can be structured as follows. Furthermore, although the through hole 15 formed in the brake ring plate 12 is illustrated as a through hole through which the lever 10A of the operation plate 10 is also inserted, the lever 10A
The through-hole through which it is inserted may be formed separately by shifting the angle in the circumferential direction.

In the device of this invention having such a configuration, when the operation plate 10 is rotated by an external operation, the flange portion 12A of the brake ring plate 12 is caused to reduce the friction of the friction plate 6 by the action of the cam ball 11 and the compression coil spring 14. When the piece 7 is pressed, the friction piece 7 separates from the flange portion 3A of the input hub 3 against the pressing force of the compression coil spring 13, and the transmission of torque from the input hub 3 to the output hub 5 is interrupted. At the same time, the cut and raised portion 16 of the mounting plate 8 prevents the brake ring plate 12 from rotating, and the output hub 5 is braked by the frictional engagement between the flange portion 12A of the brake ring plate 12 and the friction piece 7. The brake is activated to hold the lawn mowing cutter fixed to the output hub 5 stationary.

On the other hand, the operation plate 10 is rotated in the opposite direction, and the flange portion 12A of the brake ring plate 12 is rotated by the action of the cam ball 11.
When the friction piece 7 separates from the friction piece 7, the friction piece 7 of the friction plate 6, which is receiving the pressing force of the compression coil spring 13, is frictionally engaged with the flange portion 3A of the input hub 3. Torque is transmitted and the clutch is activated to rotate the lawn mowing cutter.

[Effects] As is clear from the above explanation, in the clutch/brake device of this invention, cut-and-raised parts bent in the axial direction and convex parts protrude alternately in the circumferential direction on the mounting plate, and the brake ring plate By forming a through-hole into which the cut-and-raised portion is inserted and a convex portion that faces the convex portion in the axial direction, the brake ring plate is attached to the mounting plate by the engagement of the cut-and-raised portion and the through-hole. In addition to regulating relative rotation, it has a ball-type cam actuating mechanism in which both ends of a compression coil spring are fitted around each convex portion and interposed between the mounting plate and the brake ring plate, so that the mounting plate and The diameter of the punched plate material used for the brake ring plate is reduced by press processing, and the material cost can be reduced.

In addition, since the rotation of the brake ring plate is regulated by the engagement between the cut and raised portion and the through hole, it is easy to form the mounting plate with the cut and raised portion and the brake ring plate with the through hole by press processing, which improves workability. and productivity can be improved.

Therefore, a clutch/brake device having a unitized ball type cam mechanism can be provided at low cost.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view showing an embodiment of the clutch/brake device of this invention, and FIG. 2 is a front view of the mounting plate. In the drawings, 1...Rotating machine, 2...Output shaft, 3...Input hub, 5...Output hub, 6...Friction plate, 8...Mounting plate, 10...Operation plate, 11...Cam ball, 1
2...Brake ring plate, 13, 14...Compression coil spring, 15...Through hole, 16...Cut and raised portion, 2
1, 22... Convex portion, 23, 24... Groove.

Claims (1)

[Scope of utility model registration request] A mounting plate 8 in which a cylindrical boss portion 8A through which the output shaft 2 of the rotating machine 1 is inserted is formed, and this mounting plate 8
A brake ring plate 12 is fitted into the boss portion 8A so as to be freely advanced and retracted only in the axial direction, and the brake ring plate 12 has a groove 23 at the sloped bottom opposite to the groove 24 at the sloped bottom formed in the brake ring plate 12 in the circumferential direction. and the boss 8A of the mounting plate 8
The operation plate 10 is fitted to be able to freely rotate at a predetermined angle.
and the cam ball 11 held between the opposing grooves 24 and 23 of the brake ring plate 12 and the operation plate 10,
A compression coil spring 14 is provided between the mounting plate 8 and the brake ring plate 12 on the outside of the cam ball 11 in the radial direction.
In the clutch/brake device having a ball type cam operating mechanism in which the brake ring plate 12 and the operation plate 10 are prevented from coming off from the boss portion 8A of the mounting plate 8 against a pressing force of 4, the mounting plate 8 The cut and raised portion 16 and the convex portion 2 are bent in the axial direction.
1 protrude alternately in the circumferential direction, and the brake ring plate 12 is formed with a through hole 15 into which the cut and raised portion 16 is inserted, and a convex portion 22 that faces the convex portion 21 in the axial direction. Accordingly, the cut and raised portion 1
6 and the through hole 15 to restrict relative rotation of the brake ring plate 12 with respect to the mounting plate 8, and the compression coil spring 14 is fitted with both ends around each of the convex portions 21 and 22. A clutch/brake device having the ball type cam operating mechanism interposed between the mounting plate 8 and the brake ring plate 12.