JPS6132526B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a device for transmitting rotational torque of an input shaft to an output side, and includes a clutch that stops rotation of the output side the moment torque transmission is cut off.
This invention relates to a brake device, and in particular is installed in a power lawn mower to instantly stop a cutting blade rotating via a clutch mechanism by means of a brake when the clutch is disengaged.

For example, when moving a power lawn mower to change the lawn mowing location, it is necessary to stop the rotation of the cutting blade for safety reasons. In this case, it is possible to stop the rotation of the cutting blade by stopping the rotation of the engine, but if the cutting blade is to be used continuously, it is necessary to restart the engine. For this reason, it is desirable to stop the rotation of the cutting blade without stopping the engine.

Therefore, as shown in US Pat. No. 4,141,439, some front-push type power lawn mowers are equipped with a clutch/brake device below the engine to stop the cutting blade without stopping the engine. This device includes a clutch disk between an input transmission disk fixed to an input shaft extending vertically downward from the drive source of a power lawn mower and an output disk rotatably supported at the lower end of the input shaft. is provided rotatably with respect to the input shaft, and a clutch spring biases the output disc in the direction of the input transmission disc, and the clutch/brake operation switching mechanism is operated to apply the biasing force of the clutch spring to the output disc via the clutch disc. is engaged with the input transmission disk to connect the clutch, transmit the rotation of the input transmission disk to the output disk, rotate the cutting blade provided on the output disk, and release the clutch/brake operation switching mechanism to generate the output. The disc is lowered against the biasing force of the clutch spring to disconnect the clutch, and the clutch/brake operation switching mechanism brakes the output disc to stop the rotation of the cutting blade.

However, this device rotatably supports the operating rod of the clutch/brake switching mechanism at the bottom of the fuselage, fixes the first cam ring, connects the input transmission disk to the input shaft with a key, and attaches a cam ball to the outer periphery of the input transmission disk. The second cam ring is sandwiched and placed opposite the first cam ring, the pin of the second cam ring is inserted into the groove of the first cam ring and supported on one end of the operating rod, and the input transmission disk is fitted with a clutch having approximately the same diameter as the disk. The disks are arranged facing each other and a pressure ring is arranged around the outer periphery, and the output disk, which has a larger diameter than the input transmission disk, is provided so as to be rotatable coaxially with the input shaft, and the output shaft is rotatably supported at the bottom of the housing. A disc-shaped clutch spring is placed between the bearing and the output disc, and assembly is accomplished by fixing the housing to the lower part of the fuselage.

Therefore, each component must be assembled one after another, which requires a lot of work and there is a risk of incorrect assembly. Furthermore, since it was a wet type, the structure was complicated.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a dry type clutch/brake device with a simple structure in which a clutch/brake mechanism and a clutch/brake operation switching mechanism are each made into a unit to facilitate assembly and to minimize incorrect assembly. It is said that

SUMMARY OF THE INVENTION Accordingly, the present invention provides a clutch/brake device comprising a clutch/brake unit and a clutch/brake operation switching unit, wherein the clutch/brake unit includes a collar member having a hollow portion fixed to the tip of an input shaft. an input transmission disk whose inner peripheral edge is fixed to the collar member; an output member rotatably provided to the collar member via a bearing; an input transmission disk and an output member having a diameter larger than that of the input transmission disk. a lining plate disposed between the lining plate and the output member so as to be able to rotate integrally with the output member; a lining plate that is compressed between the lining plate and the output member and biases the lining plate toward the input transmission disk to transmit input when not braking; and a clutch spring that engages the lining plate with the transmission disk. a retainer formed in the axial direction of the shaft;
a pressure plate having an inner circumferential edge fixed to the retainer and forming a brake torque receiving surface capable of engaging the lining plate on the outer side of the outer circumferential edge of the opposing input transmission disk; an operating cam member that is provided so as to be able to switch a predetermined angle and whose movement is restricted in the direction opposite to the pressure plate; and an operating cam member that is disposed between the operating cam member and the pressure plate and formed on the inner peripheral edge; a cam plate whose outer periphery is fixed to the body while the protruding piece is engaged with the guide groove; a cam ball disposed between the cam plate and the operating cam member; between the cam plate and the pressure plate; A brake spring is compressed to press the cam ball against the operating cam member and bias the pressure plate in the direction in which the pressure plate can be engaged with the lining plate. is loosely mounted so that the operating cam member is on the fuselage side, the cam plate is fixed to the fuselage, and the clutch
The collar member of the brake unit is attached and fixed to the input shaft so that the input transmission disk faces the pressure plate.

Hereinafter, an embodiment in which the present invention is applied to a power lawn mower will be described with reference to the drawings.

The figures show one embodiment of the clutch/brake device of the present invention used in a power lawn mower. Fig. 1 is a sectional front view, Fig. 2 is a partially cutaway plan view, and Fig. 3 is a partially cutaway plan view. It is a bottom view.

As shown in FIG. 1, a power lawn mower using the clutch/brake device of the present invention has a bottom outer surface at the tip of an input shaft 4 which passes through an engine mounting 3 at the bottom of the power lawn mower and projects downward. An output member 11 having a cutting blade (not shown) fixed thereon is rotatably supported, and a clutch/brake mechanism is interposed between the input shaft 4 and the output member 11 to provide a clutch/brake mechanism.
By pulling the operating rod 24 of the brake operation switching mechanism in the direction of arrow A (shown in FIGS. 2 and 3) via a cable (not shown), the brake state is released using the operating rod 24, and Connect the clutch and connect the engine (not shown) that is the driving source.
The rotation of the input shaft 4, which is rotating at the By releasing the cable, the operating lever 24 was returned in the direction of arrow C, the clutch mechanism was disconnected, and the rotational torque of the output member 11 was fixed to the engine mounting 3 via the pressure plate 16. The rotation of the output member 11 is stopped by applying a brake using the cam plate, thereby stopping the rotation of the cutting blade.

As shown in FIG. 1, the clutch/brake device used in a power lawn mower is a clutch/brake device that protrudes downward through an engine mounting 3 that forms a part of the machine body at the bottom of the power lawn mower. A clutch/brake mechanism is provided at the tip of the input shaft 4, and a clutch/brake operation switching mechanism is provided as a unit between the clutch/brake mechanism and the engine mounting 3 to facilitate assembly.

First, the clutch/brake unit will be explained with reference to FIGS. 1 and 3. The clutch/brake unit includes a collar member 6, an input transmission disk 5, an output member 11, a lining plate 13, and a clutch spring 14.

The collar member 6 has a hollow portion into which the tip of the input shaft 4 is inserted, and has a collar portion for positioning approximately in the center of its body, and a lower end bent inward where the tip end surface of the input shaft 4 comes into contact. Flange portions are respectively formed.
An input transmission disk 5 is provided on the upper part of this collar member 6.
are fitted and positioned and fixed on the upper surface of the collar.

A bearing 7 is positioned and fitted to the lower part of the collar member 6 on the lower surface of the collar, and an output member 11 is fitted to the outer race of the bearing 7 and is rotatably supported with respect to the collar member 6. .
This output member 11 has a larger diameter than the input transmission disk 5, has a through hole for the collar member 6 formed in its center, and bends its outer periphery downward to form a bearing 7.
A fitting part is formed, the outer periphery of the fitting part is bent horizontally to form a mounting plane, a blade set screw hole 12 is provided in this mounting plane, and a cutting blade (not shown) is provided at the bottom of the mounting plane. is fixed by a cutting blade set screw (not shown) screwed into the screw hole 12, and four guide grooves 11a are formed at equal intervals on the outer periphery.

A lining plate 13 is arranged between the input transmission disk 5 and the output member 11 so as to be axially movable and rotatable with respect to the input shaft 4 . This lining plate 13 has approximately the same diameter as the output member 11, has a through hole formed in the center thereof into which the fitting portion of the bearing 7 of the output member 11 is loosely inserted, and faces the input transmission disk 5 on the outer periphery thereof. A ring-shaped clutch lining 15 is fixed concentrically with the input shaft 4 on a lining mounting surface, and a control surface is provided on the outer periphery of the mounting surface and outside the periphery of the input transmission disk 5, respectively. A guide piece 13a is formed concentrically around the shaft 4 and bent in the direction of the output member 11 at a position corresponding to the guide groove 11a of the output member 11 on the periphery.
3a in the guide groove 11a to allow the input shaft 4 of the lining plate 13 to move in the axial direction,
When the lining plate 13 is rotating, the output member 11 is rotated via the guide piece 13a and the guide groove 11a, and when the lining plate 13 stops, the guide groove 11a is regulated by the guide piece 13a, and the output member 11 is also rotated. Stop rotation.

A clutch spring 14 is compressed between the lining plate 13 and the output member 11, and biases the lining plate 13 in the direction of the input transmission disk 5, thereby inputting the clutch lining 15 fixed to the lining mounting surface of the lining plate 13. It is designed so that it can be pressed into contact with the transmission disk 5.

On the other hand, as shown in FIGS. 1 and 2, the clutch/brake operation switching unit is operated by retainer 1.
8, pressure plate 16, operation cam member 2
3, a cam plate 1, a cam ball 28, and a brake spring 29.

The retainer 18 has a hollow hole that is loosely installed on the side of the input shaft 4, and a guide groove 19 in the axial direction of the input shaft 4 is formed in the upper part of the retainer 18 to face the input shaft 4, and a guide groove 19 is formed in the lower part of the retainer 18. Flange part 1 bent outward
8a is formed.

A pressure plate 16 is loosely mounted on the retainer 18, and an inner peripheral edge 16a is fixed to the upper surface of the flange portion 18a. This pressure plate 16 has a larger diameter than the input transmission disk 5, and a portion located on the outer periphery of the input transmission disk 5 is bent downward, and further bent in the outer periphery direction to form a lining plate. A brake torque receiving surface is formed opposite to the braking surface 13, and a ring-shaped brake lining 17 is fixed to this receiving surface concentrically with the input shaft 4.

Further, the cam plate 1 is loosely mounted on the retainer 18, and the protruding piece 20 formed protruding from the inner peripheral edge of the cam plate 1 engages with the guide groove 19 of the retainer 18.
Mounting holes 2 for fixing to the bottom surface of the engine mounting 3 on the outer periphery with mounting bolts (not shown)
It forms multiple pieces.

An operation cam member 23 is inserted into the upper part of the retainer 18 so as to be movable and rotatable in the axial direction of the retainer 18, and its upward movement is restricted by a locking ring 21 and a C ring 22 fixed to the upper end of the retainer 18. By fixing the operating rod 24 to the member 23 with a bolt 25 and rotating the operating rod 24 in the direction of arrow A or arrow C in FIGS. 2 and 3, the operating cam member 23 can be moved to a specified position. Rotate the angle.

On the surface of the cam plate 1 facing the operating cam member 23, ball clamps 26 which are inclined and deepen in the reaction direction of the operating rod 24 are formed at three intervals.
On the other hand, a ball clamp 27 is formed on the surface of the operating cam member 23 facing the cam plate 1 so as to correspond to the ball clamp 26 and is inclined and deepens in the direction in which the operating rod 24 is actuated. A cam ball 28 is provided between these ball clamps 26 and 27 so as to roll on the respective inclined surfaces 26a and 27a, and the operation cam member 23 is arranged so that the cam ball 28 is at the deepest position of the ball clamps 26 and 27. At some point, it is at the closest position to the cam plate 1, and this state is taken as the initial position of the operating rod 24.

Six brake springs 29 are compressed between the cam plate 1 and the pressure plate 16 to constantly urge the pressure plate 16 toward the lining plate 15. The spring force of this spring 29 is set to be greater than the spring force of the clutch spring 14. As a result, the operating cam member 23 is always urged toward the cam plate 1 via the locking ring 21, and in the initial position of the operating rod 24,
The cam ball 28 is held at the deepest position of the ball clamps 26 and 27, thereby pressing the brake lining 17 of the pressure plate 16 against the braking surface of the lining plate 13, and the clutch lining 15 is separated from the input transmission disk 5. The condition is maintained.

To assemble the clutch/brake unit configured in this way and the clutch/brake operation switching unit, first insert the retainer 18 onto the input shaft 4 protruding from the machine body with the operating cam member 23 facing the engine mounting 3. The cam plate 1 is fixed to the engine mount 3 by inserting a mounting bolt into the mounting hole 2 formed on the outer circumferential edge of the cam plate 1, and the retainer 18 is attached to the protrusion 20 of the cam plate 1. The collar member 6 is supported movably in the axial direction of the input shaft 4, and then the collar member 6 is fitted onto the input shaft 4 so that the input transmission disk 5 faces the pressure plate 16. is brought into contact with the tip of the input shaft 4, and the fixing bolt 9 is screwed onto the tip of the input shaft 4 via the spring washer 10 so that the washer 8 holds the bearing 7, and the clutch/brake unit is assembled. is fixed to the input shaft.

Note that 30 is a cover attached to the cam plate 1 with screws 31, and 32 is a drain hole formed in the output member 11.

Next, the operation of this embodiment will be explained. 1st
As shown in the figure, in the braking state where the brake spring 29 is stretched by the set load, the cam ball 28 is located at the deepest position of the ball clamps 26, 27, and the distance between the operating cam member 23 and the cam plate 1 is thereby reduced. At the minimum, the operating rod 24 is in the initial position, while the lining plate 13 is pressed by the pressure plate 16, causing the clutch spring 14 to contract and the clutch lining 15 to compress.
is spaced apart from the input transmission disk 5 without contacting it. Therefore, the rotational torque of the input shaft 4 and the input transmission disk 5 is not transmitted to the output member 11,
The mower blade (not shown) remains stationary and the engine maintains an idling operating state.

Next, when rotating the cutting blade, pull the cable (not shown) connected to the operating rod 24,
When rotated in the direction of arrow A in the figures and FIG. 3, the operating cam member 23 rotates by a predetermined angle with respect to the cam plate 1 fixed to the body. At this time, the cam ball 28 is attached to the ball clamps 26, 2.
As a result, the operating cam member 23 rotates and moves away from the cam plate 1, and accordingly, the locking ring 21 engages the operating cam member 23. The retained retainer 18 is guided by the protrusion 20 of the cam plate 1 fitted in the guide groove 19 and rises without rotating, pushing the pressure plate 16 toward the cam plate 1 against the brake spring 29. move it. As this movement progresses, the lining plate 13 follows the brake lining 17 while maintaining its pressure contact state due to the spring force of the clutch spring 14 and moves toward the input transmission disk 5, and the clutch lining 15 comes into contact with the input transmission disk 5. On the other hand, pressure plate 16
moves upward, the brake lining 17 separates from the lining plate 13, the brake engagement state is released, the lining plate 13 rotates together with the input transmission disk 5, and the clutch is connected. As a result, the power of the input shaft 4 is transmitted to the output member 11 via the collar member 6, the input transmission disk 5, and the lining plate 13, and the motive power of the input shaft 4 is transmitted to the output member 11 via the collar member 6, the input transmission disk 5, and the lining plate 13.
Rotate in the direction of arrow B in the figure and FIG.

Once the cable is released, the pressure plate 16 is pushed downward in FIG. 13
is pushed downward to separate the clutch lining 15 from the input transmission disk 5 and disconnect the lining plate 13 from the input transmission disk 5,
This brakes the rotation of the lining plate 13 and stops the rotation of the cutting blade.

Accordingly, the operating rod 24 and the operating cam member 23 rotate together in the direction of arrow C in FIGS. 2 and 3 and return to the initial position, and the cam ball 28 is held at the deepest position of the ball clamps 26 and 27. Ru.

As described above, the present invention comprises a clutch/brake mechanism consisting of a collar member, an input transmission disk, an output member, a lining plate, a clutch spring, a retainer, a pressure plate, a cam plate, a cam ball, and a brake spring. The clutch/brake operation switching mechanism is made into a unit, a clutch/brake unit and a clutch/brake operation switching unit, and the clutch/brake unit operation switching unit is assembled to the input shaft, making manufacturing easy and preventing incorrect assembly. It is possible to reduce the amount. Furthermore, since the brake spring is incorporated into the clutch/brake operation switching unit, brake vibrations can be absorbed by the brake spring, allowing long-term use of each component and stabilizing long-term brake switching.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a sectional front view, FIG. 2 is a partially cutaway plan view, and FIG. 3 is a partially cutaway bottom view. DESCRIPTION OF SYMBOLS 1... Cam plate, 4... Input shaft, 5... Torque transmission disk, 6... Collar member, 7... Bearing, 11... Output member, 13... Lining plate, 14... Clutch spring, 16
...pressure plate, 18...retainer,
19...Guide groove, 20...Protrusion piece, 23...Operating cam member, 24...Operating rod, 28...Cam ball, 29...Brake spring.

Claims (1)

[Claims] 1. A clutch/brake device comprising a clutch/brake unit and a clutch/brake operation switching unit, wherein the clutch/brake unit has a hollow portion fixed to the tip of the input shaft 4. a collar member 6; an input transmission disk 5 whose inner peripheral edge is fixed to the collar member 6; an output member 11 rotatably provided to the collar member 6 via a bearing 7; a lining plate 13 provided between the input transmission disk 5 and the output member 11 so as to be movable in the axial direction and rotatable integrally with the output member 11; , a clutch spring 14 that urges the lining plate 13 in the direction of the input transmission disk 5 and engages the lining plate 13 with the input transmission disk 5 when not braking; A retainer 18 has a guide groove 19 formed in the axial direction of the input shaft 4 in the cylindrical body having a hollow hole, which is loosely mounted on the body side of the input shaft 4; a pressure plate 16 formed with a brake torque receiving surface capable of engaging with the lining plate 13 on the outside of the outer peripheral edge of the input transmission disk 5; Operation cam member 23 provided with restricted movement in the direction of shear plate 16
and; the operating cam member 23 and the pressure plate 1
6 and formed on the inner peripheral edge.
a cam plate 1 which engages with a guide groove 19 and whose outer peripheral edge is fixed to the body; a cam ball 28 disposed between the cam plate 1 and an operating cam member 23; A cam member 23 is arranged between the shear plates 16 and operates a cam ball 28.
Pressure plate 16
A clutch/brake device comprising: a brake spring 29 for biasing the clutch in a direction that allows the clutch to engage with the lining plate 13;