JPH0247785Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a device that transmits the rotational torque of an input shaft protruding from a body (housing) such as an engine case to the output side. A clutch that shuts off and stops rotation on the output side.
Regarding brake equipment.

[Conventional technology]

BACKGROUND OF THE INVENTION Conventionally, for example, when moving a power lawn mower to change the mowing location, it has been necessary to stop the rotation of the cutting blade for safety reasons. In this case, it is desirable to stop only the rotation of the cutting blade without stopping the engine.

The applicant has previously proposed this type of technology,
We proposed a clutch/brake device with a simple structure as shown in No. 61-32526.

In this technology, a lining plate that engages with an output member is movably provided in the axial direction on an input shaft on which an input transmission disk is attached, and the lining plate is brought into contact with the input shaft by the biasing force of a brake spring. a pressure plate that engages and disengages the lining plate from the input transmission disk; and an operating cam plate that moves the pressure plate in the axial direction of the input shaft via a plurality of cam mechanisms by rotating an operating rod. is provided.

The cam mechanism is composed of a cam groove formed opposite to a pressure plate and a cam operation plate, and a cam ball attached to the cam groove. The cam groove of the operating cam member is formed to be inclined and deepen in the operating direction of the operating rod, and when the cam ball is located at the deepest part of both cam grooves, The operation lever is set at the initial position where the blade stops, and when the cam ball is positioned on the upper side of the rolling slope of both cam grooves, the cutting blade is set at the operating position where it rotates.

The operating rod is connected to an operating lever via a wire cable, and when the lever is operated, the operating rod is rotated to rotate or stop the cutting blade without stopping the engine.
An adjustment bolt is installed to adjust the play with the operating rod.

[Problem that the invention attempts to solve]

However, in the above-mentioned device, when the operating rod is rotated to perform clutch and brake operation, each cam ball of the cam mechanism rolls unevenly within the cam groove, resulting in a lack of smooth operation.

Further, although the play adjustment of the wire cable is carried out in the initial state of non-operation, the operating rod and the pressure plate are rotated by the wire cable, making it difficult to perform the adjustment work.

Therefore, the present invention reliably locks the cam balls of the cam mechanism in the operating position or the initial position, and synchronizes the rolling of multiple cam balls to ensure reliable operation, while also making it easier to adjust wire cables. The object of the present invention is to provide a clutch/brake device in which the shear plate does not rotate.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a lining plate movable in the axial direction of the input shaft that engages with the output member on the input shaft on which the input transmission disk is mounted, and a lining plate on the input shaft. A clutch equipped with a pressure plate that contacts the plate and engages and disengages the lining plate from the input transmission disk, and an operating cam plate that moves the pressure plate in the axial direction of the input shaft via a cam mechanism. - In the brake device, the cam mechanism includes a cam groove formed to face the pressure plate and the operating cam plate, and a cam ball attached to the cam groove, and the cam ball is installed in the deepest part of the cam groove. The holding recess is characterized in that stopper protrusions for regulating the rolling of the cam ball are formed on the top surfaces of the rolling slopes of the cam grooves that are continuous to the deepest parts of the holding recesses.

〔Example〕

An embodiment of a clutch/brake device suitable for a power lawn mower will be described below with reference to the drawings.

In the clutch/brake device 1, an output member 4, which has a cutting blade (not shown) fixed to the outer surface of the bottom part, is rotatable at the tip of an input shaft 3 that penetrates the lower part of a body (housing) 2 such as an engine case and projects downward. A clutch is connected between the input shaft 3 and the output member 4.
A brake means is interposed, and an operating rod 7 operated by a wire cable 6 is connected to an operating cam plate 5 of the brake means.

By pulling the wire cable 6 through this operating rod 7,
When rotated in the direction of arrow A (shown in Figure 4), the brake state is released, the clutch is engaged, and
The rotation of the input shaft 3, which is rotated by an engine (not shown) as a driving source, is transmitted to the output member 4, and this rotation rotates the cutting blade to mow the lawn, and the wire cable 6 is When released, control rod 7
returns in the direction of arrow B (Fig. 4), disconnects the clutch, receives the rotational torque of the output member 4 at the fuselage 2, applies the brake, and stops the rotation of the output member 4.
It is designed to stop the rotation of the cutting blade.

The clutch/brake device 1 used in a power lawn mower includes a lower part of a body 2 of the power lawn mower.
An input shaft 3 that is rotationally driven by an engine is disposed protrudingly, and a collar member 8 is disposed on the outer periphery of the base of the input shaft 3. This collar member 8 is fixed to the fuselage 2 by a plurality of fixing bolts 9. It is connected and supported by a nut 11 to a mounting plate 10 attached to the lower member.

Further, a boss portion 12a of the input transmission disk 12 is pivotally attached to the lower end of the input shaft 3 so as to be rotatable integrally with the input shaft 3 using a half-moon key 13.
A washer 16 inserted through a fixing bolt 15 screwed onto the tip of the input shaft 3 supports the lower surface of the bearing 14 fitted on the outside.

The output member 4 is fitted onto the outer race 14a of the bearing 14 so as to be rotatable relative to the input transmission disk 12.

This output member 4 has a larger diameter than the input transmission disk 12, has a through hole for the boss portion 12a of the input transmission disk 12 formed in the center, and bends its outer periphery downward to accommodate the fitting portion of the bearing 14. form,
The outer periphery of the fitting part is bent horizontally to form a mounting plane, and the blade set screw hole 1 is formed in this mounting plane.
7, and a cutting blade (not shown) is screwed and fixed to the bottom of the mounting plane, and an appropriate number of guide grooves 18 are formed at equal intervals on the outer periphery.

A lining plate 19 is arranged between the input transmission disk 12 and the output member 4 so as to be axially movable and rotatable with respect to the input shaft 3 .

This lining plate 19 is formed to have approximately the same diameter as the output member 4, and has a through hole bored in the center so that the outer periphery of the fitting portion of the bearing 14 of the output member 4 can be moved in the axial direction of the input shaft 3. A ring-shaped lining 20 is fixed concentrically with the input shaft 3 on the outer periphery of the upper surface, and a guide piece 19a is provided on the outer periphery of the output member 4 at a position corresponding to the guide groove 18 of the output member 4. The guide piece 19a is bent in the direction, and the guide piece 19a is engaged with the guide groove 18, and a lining plate 19 is always urged in the direction of the input transmission disk 12 on the outer periphery of the fitting part of the bearing 14 of the output member 4. A clutch spring 21 is compressed.

The operation cam plate 5 is disposed between the input transmission disk 12 and the mounting plate 10.
is installed.

This operation cam plate 5 is provided so that its inner circumferential side is fitted into a plurality of guide holes 22 provided on the outer circumference of the collar member 8 so as to be switchable at a predetermined angle.
The collar member 8 is supported by a flange portion 8a protruding from the lower end thereof, and is rotated by a predetermined angle by an operating rod 7 fixed to the operating cam plate 5.

A pressure plate 23 is disposed between the operation cam plate 5 and the mounting plate 10.

This pressure plate 23 is attached to the collar member 8.
It is mounted on the outer periphery of the input transmission disk 1.
2 and the operating cam plate 5,
The parts of the input transmission disk 12 and the operation cam plate 5 located outside the periphery are bent downward to form the operation cam plate 5 and the input transmission disk 1.
2, a notch is formed in a part of the peripheral wall through which the operating rod 7 of the operating cam plate 5 passes, and the outer periphery of the peripheral wall is further perpendicular to the input shaft 3 in the outer circumferential direction. A brake torque receiving surface 24 is formed by bending the lining plate 19 so as to face the lining 20 of the lining plate 19, and a pressure plate is formed between the torque receiving surface 24 and the outer periphery of the mounting plate 10. A plurality of brake springs 25 are compressed to urge the brake springs 23 toward the lining plate 19.

Operation cam plate 5 and pressure plate 23
Three sets of cam mechanisms 27 are arranged at equal intervals between the two.

As shown in detail in FIGS. 1 and 2, this cam mechanism 27 has a cam groove 2 provided facing the operating cam plate 5 and the pressure plate 23.
8, 29, and both cam grooves 28, 29 and a cam ball 30 installed between them. ), and the cam groove 29 of the pressure plate 23 is formed so that the rolling slope 29a becomes deeper in the reaction direction of the operating rod 7 (direction of arrow B in FIG. 4). When the cam ball 30 is at the deepest part of the cam grooves 28 and 29, the pressure plate 23 is located closest to the operating cam plate 5, and this state is the initial position of the operating rod 7. .

Each cam groove 28, 29 has recesses 31, 3 at the deepest part.
2 is also on the top surface of the rolling inclined surfaces 28a and 29a,
Stopper protrusion 3 that restricts the rolling of the cam ball 30
3 and 34 are provided respectively, and the recesses 31 and 34 are provided respectively.
On the opposite side of the stopper protrusions 33 and 34 with 32 in between, there is a pressure plate 2 on the operating cam plate 5.
In the initial state in which the stopper projections 33 and 34 are close to each other, the escape recess 28 is formed so that the stopper projections 33 and 34 do not interfere with each other.
b, 29b are provided.

The recesses 31 and 32 are for holding the cam balls 30 in the initial state at the deepest position, and when the operating rod 7 is rotated from this initial position in the operating direction, each cam ball 30 is subjected to a torque higher than the set value. When this happens, these cam balls 30 will fit into the recesses 31 and 32.
simultaneously come out of the rolling slope surfaces 28a, 29a.
roll upward.

Therefore, in a conventional cam groove that does not have recesses 31 and 32, each cam ball starts rolling irregularly from the deepest part of the cam groove due to factors such as slip, resulting in a lack of smooth operation. However, in this embodiment, the plurality of cam balls 30 can be simultaneously synchronized by the recesses 31 and 32, so that smooth operation can be achieved.

Furthermore, a wire cable 6 connected to the operating rod 7
When adjusting the play of the wire cable 6 with the adjusting bolt 35 inserted in the cam ball 30, even if some rotational torque is applied to the operating rod 7, the cam ball 30 is held at its deepest position by the recesses 31 and 32. Therefore, adjustments can be made without rotating the cam plate 5, resulting in excellent workability.

Further, the stopper protrusions 33 and 34 can be moved to the rolling inclined surfaces 28 and 29 of the cam grooves 28 and 29 by rotating the operating rod 7.
8a, 29a to regulate the upper limit position of the cam balls 30 that roll upward.
Even if the cam balls 30 roll unevenly on the respective rolling inclined surfaces 28a and 29a, in the operating state where the lining 20 of the lining plate 19 is in contact with the input transmission disk 12, any of the cam balls 30 will roll on the stopper protrusion 33. , 34, so that the pressure plate 23 and the lining plate 19 can be arranged without tilting.

Further, even if a rotational torque exceeding a predetermined value is applied to the operating cam plate 5, the cam ball 30 is stopped by both the stopper projections 33, 34 and will not come out of the cam grooves 28, 29.

The spring force of the brake spring 25 is set larger than the spring force of the clutch spring 21. As a result, the pressure plate 23 is always urged to press the operating cam plate 5 toward the input transmission disk 12 via the cam ball 30, and when the operating rod 7 is in its initial position, the cam ball 30 is pushed into the cam grooves 28, 29. The pressure plate 2 is held at the deepest position of the brake lining 20 of the lining plate 19.
3, the clutch spring 21 is compressed, and the lining 20 is kept separated from the input transmission disk 12.

Next, the operation of this embodiment will be explained.

In a braking state in which the brake spring 25 is expanded under a set load, the cam ball 30 is held in the cam grooves 28 and 29 held in the recesses 31 and 32.
As a result, the distance between the pressure plate 23 and the operating cam plate 5 is the minimum, and the operating lever 7 is at the initial position as shown by the solid line in FIG.

On the other hand, the lining plate 19 is pressed by the pressure plate 23, the clutch spring 21 contracts, and the lining 20 does not come into contact with the input transmission disk 12, but is separated from it with a predetermined clearance.

Therefore, the rotational torque of the input shaft 3 and the input transmission disk 12 is not transmitted to the output member 4, and the engine remains in an idling state with the mower blade (not shown) remaining stationary.

Next, when rotating the cutting blade, pull the wire cable 6 connected to the operating rod 7 and rotate the operating rod 7 in the direction of arrow A in FIG. It rotates by a predetermined angle shown by the imaginary line in the figure.

At this time, rotational torque exceeding the setting is applied to the cam balls 30 of the cam mechanism 27, and each cam ball 30 simultaneously escapes from both the recesses 31 and 32, and the rolling inclined surfaces 28a and 2 of the cam grooves 28 and 29
It rises while rolling on 9a, and is regulated by raised position stopper projections 33 and 34.

As a result, the pressure plate 23 moves toward the body 2 by being guided by the guide hole 22 of the collar member 8 against the brake spring 25. Along with this movement, the lining plate 19 moves toward the input transmission disk 12 while the lining 20 follows the torque receiving surface 24 of the pressure plate 23 due to the spring force of the clutch spring 21, and the inner peripheral side of the lining 20 receives the input. in contact with the transmission disk 12, while the pressure plate 2
3 further moves upward and separates from the lining 20, and the engagement state is released, and the lining 20 comes into pressure contact with the input transmission disk 12, which rotates next.

The lining plate 19 rotates together with the input transmission disk 12 to effect clutch connection. As a result, the rotational force of the input shaft 3 is
Input transmission disk 12 and lining plate 1
It is transmitted to the output member 4 via 9 and rotates the cutting blade.

Furthermore, when the wire cable 6 is released, the operating rod 7 rotates in the direction of arrow B in FIG. That is, the pressure plate 23 is pushed downward by the restoring force of the brake spring 25, and the torque receiving surface 24 of the pressure plate 25 comes into pressure contact with the lining 20 to start braking, and the lining plate 19 is pushed downward. lining 2.
0 is separated from the input transmission disk 12, the connection between the lining plate 19 and the input transmission disk 12 is cut off, and the rotational force of the lining plate 19 is
The rotation of the cutting blade is stopped by being braked by the torque receiving surface 24 of the pressure plate 23.

Further, the operating rod 7 and the operating cam plate 5 rotate together and return to the initial position, and each cam ball 30 is held in the recesses 31 and 32 at the deepest parts of the cam grooves 28 and 29, respectively.

As described above, in this embodiment, the opposing cam grooves 2
Since the recesses 31 and 32 for holding the cam ball 30 are provided at the deepest parts of the recesses 8 and 29, the recesses 31 and 3
2, each cam ball 3
0 can be synchronized all at once to ensure smooth operation, and even if some rotational torque is applied to the operating rod 7 when adjusting the play of the wire cable 6 in the initial state, the cam ball Since the cam plate 30 is held at the deepest part by the recesses 31 and 32, adjustment can be made without rotating the cam plate 5, and workability can be improved.

Furthermore, since the stopper protrusions 33 and 34 are formed at the tops of the rolling inclined surfaces 28a and 29a that are continuous with the deepest parts of the cam grooves 28 and 29, in the operating state where the lining 20 is pressed against the input transmission disk 12,
Each cam ball 30 is locked at the same height by the stopper protrusions 33, 34, so that the lining 20 can be set in a state without inclination, and smooth operation can be achieved.

[Effect of idea]

As described above, in the clutch/brake device of the present invention, the cam mechanism provided between the operating cam plate and the pressure plate is attached to the cam groove formed opposite to both plates, and the cam mechanism is installed in the cam groove. A recess for holding the cam ball is provided at the deepest part of the cam groove, and a stopper protrusion for restricting the rolling of the cam ball is provided on the top surface of the inclined rolling surface of the cam groove where the cam ball rolls. Because of this shape, the cam balls can be locked in the operating position or the initial position of non-operation, and the rolling of multiple cam balls can be synchronized for smooth operation.The pressure plate can also be used for wire cable adjustment work. Since there is no rotation, work efficiency can be improved.

[Brief explanation of drawings]

The figures show one embodiment of the present invention, in which Fig. 1 is a sectional view taken from the side of Fig. 4 showing the initial state of the cam mechanism, Fig. 2 is a vertical sectional view showing the operating state of the cam mechanism, and Fig. 3 is a longitudinal sectional view showing the operating state of the cam mechanism. The figure is a sectional front view of the clutch/brake device, and FIG. 4 is a partially cutaway bottom view. 1...Clutch/brake device, 2...Airframe, 3...
Input shaft, 4... Output member, 5... Operation cam plate,
6... Wire cable, 7... Operating rod, 8... Collar member, 10... Mounting plate, 12... Input transmission disk, 18... Guide groove, 19... Lining plate, 20... Lining, 21... Clutch spring, 23... Pleats Shear plate, 25...
Brake spring, 27...Cam mechanism, 28,2
9...Cam groove, 28a, 29a...Rolling slope, 28
b, 29b...Escape recess, 30...Cam ball, 3
1, 32... recess.

Claims (1)

[Scope of utility model registration request] A lining plate that engages with an output member is provided movably in the axial direction of the input shaft on an input shaft on which an input transmission disk is mounted, and a lining plate that contacts the lining plate is placed on the input shaft to connect the lining plate to the input transmission disk. In the clutch/brake device, the cam mechanism is provided with a pressure plate that engages and disengages from the input shaft, and an operation cam plate that moves the pressure plate in the axial direction of the input shaft via a cam mechanism. The cam groove is provided with a cam groove formed to face the shaft plate and the operating cam plate, and a cam ball attached to the cam groove. A clutch/brake device characterized in that stopper protrusions are formed on the top surfaces of the rolling inclined surfaces for regulating the rolling of the cam balls.