JPH08187024A - Brake device for emergency - Google Patents

Abstract

PURPOSE: To obtain the emergency brake device capable of automatically connecting a clutch disposed in the midway of a powder-transmitting path, when an engine is driven to transmit the power to a working section, and if necessary, capable of immediately disconnecting the clutch to stop the driving of the working section in the braked state. CONSTITUTION: In the emergency brake device 20 in which a centrifugal clutch 40 is disposed in a transmission case 21, the clutch shoe-attached drive side brake board of the centrifugal clutch is disposed so as to slide in the direction of a driven side clutch board along the rotation axis with a centrifugal force acting on a clutch sliding member, and the base end of a driven side cover case is disposed in a state enabling to slide the base end with respect to the transmission case. A driven shaft incorporated with the driven side clutch board of the centrifugal clutch is rotatably supported in the driven side cover case, and an energizing member is disposed between the driven side cover case and the transmission case. Frictional surfaces for the brake are disposed on the back surface of the driven side clutch board and on the inner surface of the transmission case faced to the back surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emergency braking device for a power transmission device, and more particularly to an emergency braking device for a power transmission device of a portable working machine such as a brush cutter.

[0002]

2. Description of the Related Art Conventionally, in a portable working machine such as a brush cutter, power is transmitted from a prime mover such as an internal combustion engine or an electric motor to a working section such as a cutting blade by a centrifugal clutch in the middle of its power transmission path. The centrifugal force is used as the power from the prime mover to put the centrifugal clutch in the clutch-in state, and the working unit is driven to carry out work such as brush cutting. And, in the conventional transmission of the power, even when the centrifugal clutch is in the clutch-out state, the power transmission system tends to continue the rotation for a while due to the inertial force, so in order to quickly stop the rotation, An emergency braking device is provided separately from the clutch.

As a means for providing the emergency brake device, for example, a brake flange is arranged in the vicinity of the rotary blade of the brush cutter, and the lining of the brake flange is brought into contact with the rotary blade when the rotation of the rotary blade is stopped. By means of which the rotation of the rotary blade is stopped by
No. 1378), or a brake shoe is integrally provided on the clutch shoe of the centrifugal clutch, while a brake sleeve is provided on a fixed portion such as a transmission case so that the brake shoe provided on the clutch shoe when the centrifugal clutch is clutched out. One that stops the rotation of the driven shaft to the working part by contacting with the brake sleeve (Japanese Utility Model Publication No. 3-17077), and further, from the clutch shoe provided on the drive shaft and the clutch drum provided on the driven shaft. In the centrifugal clutch, a brake lining is provided on the clutch drum, and a brake lining is provided on a sliding body fitted to the driven shaft so as to be movable back and forth, and the sliding body is provided on the brake lining of the clutch drum when the clutch is out. Work by contacting the brake lining of Those for restraining the rotation of the driven shaft (Japanese Utility Model 54-1373 JP) are proposed to.

[0004]

However, in the case where a centrifugal clutch is provided in the middle of the power transmission path from the conventional prime mover to the working portion, such a centrifugal shoe as a clutch shoe in which the centrifugal clutch is rotated by a drive shaft is used. Centrifugal force automatically shifts to the clutch-in state, and no special clutch operation is required, but this centrifugal force acts to put the centrifugal clutch in the clutch-in state immediately into the clutch-out state in which no power is transmitted. Can not do it.

This is because, for example, when the working part is driven (rotated or reciprocated) in the brush cutting work, etc., the working part comes into contact with an obstacle or the like and the driving is hindered. In that case, the centrifugal clutch is immediately put into the disengaged state of the clutch out to eliminate the transmission of the driving force,
It is necessary to reduce the load on the prime mover or prevent danger to workers, etc., but with the conventional centrifugal clutch, it is not possible to immediately disengage the clutch completely, resulting in malfunctions of various parts of the machine. There was a problem.

The present invention has been made in view of the above problems, and an object thereof is to interpose, in particular, when a prime mover is driven to transmit power to a working part, the power transmission path is provided in the middle of the power transmission path. It provides an emergency brake device of a power transmission device that automatically puts the clutch in the clutch-in state and immediately puts the clutch-out state into the disengaged state as needed. is there.

[0007]

In order to solve the above-mentioned problems, an emergency braking device according to the present invention has a centrifugal clutch inside a transmission case, and a driving side braking plate with a clutch shoe of the centrifugal clutch. Arranged to slide in the driven side clutch plate direction along the rotation axis by the centrifugal force acting on the motive element, and the base end of the driven side cover case is slidably arranged with respect to the transmission case, A driven shaft integral with the driven-side clutch plate of the centrifugal clutch is rotatably supported in the driven-side cover case, and an urging member is interposed between the driven-side cover case and the transmission case. A braking friction surface is provided on a rear side surface of the driven side clutch plate and an inner surface of the transmission case facing the rear side surface.

The urging member urges the driven-side cover case and the driven-side clutch plate to move in the drive-side braking plate direction along the rotation axis, while the driven-side cover case and the driven-side cover plate Blocking the movement of the driven side clutch plate in the direction of the driving side braking plate, and bringing the two braking friction surfaces of the driven side clutch plate and the annular flange into contact with each other, forcibly clutching the centrifugal clutch out. And a brake actuating member for bringing the brake-in state is provided.

[0009]

[Operation] In the emergency braking device with a clutch such as a brush cutter according to the present invention configured as described above, when the prime mover is driven at a predetermined rotation speed, the centrifugal clutch is automatically put into the clutch-in state, and the working unit Drives by transmitting power to a certain hair clipper blade, etc., but during work such as brush cutting, the hair clipper blade comes into contact with some obstacle, etc., and movement of the hair clipper blade is obstructed, resulting in excessive load on the prime mover. In this case, a force acts so that the prime mover and the transmission case integrated with the prime mover move relatively to the driven side cover case. That is, due to the excessive load, a force acts to move the transmission case and the driven-side cover case in a direction of compressing the biasing means, and moves the driven-side cover case with respect to the transmission case (relative movement). The driven-side clutch plate is separated from the clutch shoe to force the clutch-out state, and the rear side surface of the driven-side clutch plate makes frictional contact with the friction stopping brake member to be in the brake-in state.

[0010]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a perspective view of the entire configuration of a clipper-type brush cutter of an embodiment to which an emergency braking device of the present invention is applied. The clipper-type brush cutter 10 is provided with a clipper section having a clipper blade 13 via a gear case 12 at the tip of a driven-side cover case 11 that constitutes an operating rod. A prime mover 14 such as a small air-cooled two-cycle gasoline engine is provided at the rear end of the driven side cover case 11, and a centrifugal clutch and a brake (details) are provided between the prime mover 14 and the driven side cover case 11. The emergency braking device 20 is provided.

The power of the prime mover 14 is transmitted through the clutch provided in the transmission case 21 of the emergency braking device 20 to the driven drive shaft 47 and the gear case 12 provided in the driven side cover case 11. It is adapted to be transmitted to the hair clipper blade 13 via a bevel gear or the like (not shown). Then, between the prime mover 14 and the hair clipper blade 13 on the driven-side cover case 11 that constitutes the operation rod, a handle 16 made of a U-shaped pipe member is arranged and fixed via a handle attaching device 15. Has been done. This handle 16 has a handle grip 1
7 and 17 are attached, a throttle lever 18 is provided on one handle grip 17, and a throttle wire 19 is connected to operate the prime mover 14.

FIG. 2 shows an emergency braking device 2 of this embodiment.
3 is a sectional view taken along the line III-III in FIG. 2, and FIG. 4 is an exploded perspective view of the driven side transmission case 23 of the emergency braking device 20. The transmission case 21 fixed to the prime mover 14 is a drive side transmission case 22.
And a driven side transmission case 23. The driving side transmission case 22 has a cylindrical shape with one end fixed to the prime mover 14 and the other end serving as a joint portion with the driven side transmission case 23. The case 23, as shown in FIG.
The transmission cases 23a and 23b are symmetrically divided in half.

The joint portion 24 of the drive side transmission case 22 with the driven side transmission case 23 is constructed to have a slightly smaller outer diameter, and an annular groove 25 is formed on the outer periphery of the joint portion 24. The driven-side transmission case 23 has cylindrical portions 23a ₁ and 23b ₁ on the driving-side transmission case 22 side.
The driven-side cover case 11 side is a truncated cone cylindrical portion 23a.
_2, 23b ₂ constitute a, the driven-side transmission case 2
An annular projection 26 is formed at a joint portion of the drive shaft 3 with the drive side transmission case 22 so as to engage with the annular groove 25 of the drive side transmission case 22 and project inward.

At the outer periphery of the frustoconical cylindrical portions 23a ₂ and 23b ₂ of the driven side transmission case 23, an ear-shaped flange 27 is vertically attached to each of the joint portions of the left and right half-divided transmission cases 23a and 23b. Are installed symmetrically. Each of these ear-like flanges 27 is provided with a bolt insertion hole 29 through which a case fixing bolt 28 for fixing the half transmission cases 23a and 23b of the driven side transmission case 23 is inserted. In the half-divided transmission cases 23a, 23b, a pair of two brake actuating members 30 are vertically interposed at the joint portion of the ear-shaped flange 27.

Each of these brake actuating members 30 is swingably supported by the case fixing bolt 28, has a bolt insertion hole 30 in the middle portion, and has a brake release pressing portion on one side. 30b is provided with the engaging claw 30c on the other side. By inserting the case fixing bolt 28 into the bolt insertion hole 29 of the ear-shaped flange 27 and the insertion hole 30a of the brake operating member 30 and tightening it with a case fixing nut 33, the half transmission case 23a, The reference numeral 23b holds the brake actuating member 30 swingably and is joined and fixed to each other.

A centrifugal clutch 40 is provided in the transmission case 21. The centrifugal clutch 40 has a clutch disk 41 fixed to a drive side drive shaft 60 which is an output shaft of the prime mover 14 on the drive side. A drive-side braking plate 43 is arranged so as to face the same position as the clutch disc 41 on the same axis XX. The clutch disc 41 has a protruding claw portion 4 at the center of the surface facing the drive side braking plate 43.
On the other hand, the drive-side braking plate 43 is provided with an engaging claw portion 43a which constitutes a dog clutch by engaging with the projecting claw portion 41a. The engaging claw portion 43a of the drive-side braking plate 43 is engaged so as to wrap around the projecting claw portion 41a of the clutch disc 41, and slides in the axial line X-X direction with respect to the projecting claw portion 41a. The clutch disc 41 and the drive-side braking plate 43 are movable, and the projecting claw portion 41a and the engaging claw portion 43 are movable.
It rotates integrally through a dog clutch constituted by a and a.

A pair of half-moon shaped clutch slider engagement grooves 41b, 41b of the same shape are provided on the surface of the clutch disk 41 on the drive side braking plate 43 side, and the drive side braking plate 43 is provided. The surface on the side of the clutch disk 41 is a tapered surface whose outer peripheral direction inclines toward the side of the clutch disk 41. A pair of clutch sliders 42, 4 is provided between the clutch disc 41 and the drive side braking plate 43.
2 are arranged facing each other with respect to the axis X-X, and these clutch sliders 42, 42 have a half-moon shape as shown in FIG. Coil springs 45, 45 are attached to urge the pair of clutch sliders 42 toward each other in the central direction. The surface of the clutch slider 42 in the left-right direction in FIG. 2 is a surface perpendicular to the rotation axis XX on the clutch disk 41 side, and the clutch slider engagement of the clutch disk 41 is performed. Groove 4
1b is engaged with and slides in the radial direction, and
On the third side, the outer peripheral direction in sliding contact with the taper surface of the drive-side braking plate 43 is a taper surface inclined toward the clutch disc 41 side.

A disc-shaped clutch shoe 44 is integrally fixed to the surface of the drive side braking plate 43 opposite to the tapered surface, and at a position facing the clutch shoe 44,
A driven side clutch plate 46 is arranged. The driven side clutch plate 46 is integrally provided with a driven shaft 46b, and the driven shaft 46b is interlocked with a driven drive shaft 47 for transmitting power to the hair clipper blade 13, and
Bearings 48, 48 positioned by a snap ring 51 in the base end of the driven-side cover case 11 that constitutes the operating rod.
It is rotatably supported via.

An annular flange 49 extending radially outward is provided in the vicinity of the base end portion of the driven side cover case 11 on the centrifugal clutch 40 side, and the annular flange 49 is provided.
And the truncated cone cylindrical portion 2 of the driven side transmission case 23
A compression coil spring 50 as a biasing member is provided between the inwardly extending annular flanges 33a and 33b provided at the end portions of 3a ₂ and 23b ₂ and the driven side cover case 1
1 is provided so as to surround the outer circumference. Therefore, the driven-side cover case 11 is always pressed and moved toward the drive-side braking plate 43 together with the driven-side clutch plate 46 by the biasing force of the compression coil spring 50.

The rear side surface 46a of the driven side clutch plate 46
And the driven side transmission case 2 facing the rear side surface 46a.
Inner side surface 3 of the annular flange 31 protruding inward
1a is configured as a braking friction surface, and in the illustrated example, an annular friction stopping lining member 32 is further disposed on the inner side surface 31a. Next, the operation of the present embodiment will be described.

FIG. 2 shows the clipper type brush cutter 10 in a non-working state, in which the prime mover 14 is stopped and the centrifugal clutch 40 is not rotating, and FIG. In this state, the rotational power of the prime mover 14 is transmitted through the centrifugal clutch 40 to the hair clipper blade 1
3 shows the clutch-in state transmitted to the engine 3, and FIG. 6 shows that the rotational power of the prime mover 14 is the centrifugal clutch 4
0 is transmitted, but is not transmitted to the hair clipper blade 13, in the clutch-out state, the driven side shows the brake-in state.

When the operator of the clipper type brush cutter 10 starts the prime mover 14 from the state shown in FIG. 2, the prime mover 1
4 rotates, and the drive side drive shaft 60
To rotate. By the rotation of the drive side drive shaft 60, a member on the drive side of the centrifugal clutch 40, that is,
The clutch disc 41, the clutch sliders 42, 4
2 and the driving side braking plate 43 rotate integrally. When the operator operates the throttle lever 18 to increase the rotation to a predetermined value, the clutch sliders 42, 42 move radially outward by the rotational centrifugal force. When the clutch sliders 42, 42 move,
Due to the mutual sliding action of the tapered surfaces of the clutch sliders 42 and 42 and the tapered surface of the driving-side braking plate 43, the driving-side braking plate 43 causes the driven-side clutch plate 46 to move.
Direction, and as shown in FIG.
The clutch shoe 44, which is integral with 3, is pressed against the driven-side clutch plate 46, that is, the clutch-in state. In this state, since the clutch shoe 44 and the driven-side clutch plate 46 are in frictional contact with each other, the rotational power of the clutch shoe 44 is generated by the driven-side clutch plate 4.
It is transmitted to 6, and both rotate together. This Figure 5
In the clutch-in state, the operator grips the left and right handlebars 17 of the handlebar 16 of the clipper-type brushcutter 10.
Grasp and carry out the mowing work.

By the way, while the worker is mowing with the hair clipper type brush cutter 10, the hair clipper blade 13 comes into contact with some obstacle or the like, and the movement of the hair clipper blade 13 is impeded, so that the prime mover 14 side is moved. When overloaded, the prime mover 14 and the transmission case 2 integrated with the prime mover 14
A force acts so that 1 moves relatively to the driven-side cover case 11. That is, the transmission case 21 and the driven-side cover case 11 are pressed and moved in the clutch-in direction of the centrifugal clutch 40 by the compression coil spring 50, but due to the overload, the transmission case 21 and the transmission case 21 are separated from each other. A force acts to move the driven-side cover case 11 in the direction of compressing the compression coil spring 50, and moves (relatively moves) the driven-side cover case 11 to the right with respect to the transmission case 21 in FIG. As shown in FIG. 6, the driven side clutch plate 46 is separated from the clutch shoe 44 to be in a clutch-out state, and the rear side surface 46a of the driven side clutch plate 46 makes frictional contact with the friction stopping lining member 32. , It operates so as to be in the brake-in state. This operation prevents the prime mover 14 from being overloaded and locks the operation of the hair clipper blade 13.

The position of the brake operating member 30 shown in FIG. 6 is such that the engaging claw 30c of the brake operating member 30 is in the clutch-out state and the brake-in state so that the driven side cover case 11 is provided. 3 shows a state in which the annular flange 49 is engaged with the side opposite to the compression coil spring 50, the prime mover 14 rotates, and the clutch disc 41, the clutch slider 42, and the drive side braking plate also rotate. It shows the state.

By setting the brake actuating member 30 to the state shown in FIG. 6 by, for example, a manual operation, the driven side clutch plate 46 can be covered with the driven side clutch plate 46 regardless of whether the prime mover 14 is rotating. With the brake-in frictionally fixed, the operation of the hair clipper blade 13 can be locked. Then, to release the friction-fixed state of the brake-in, the brake release pressing portion 30b of the brake actuating member 30 is pressed with a finger so that the engaging claw 30 is released.
c is disengaged from the annular flange 49, the driven side cover case 11 is moved to the left in FIG. 6 by the bias of the compression coil spring 50, and the rear side surface 46a of the driven side clutch plate 46 is moved. Friction stop lining member 32
Away from the vehicle, and the brakes out.

Next, another embodiment of the present invention will be described with reference to FIGS.
It will be described based on. The present embodiment is an embodiment in which the emergency braking device with a clutch is applied to the rotary blade type brush cutter,
In the description of the illustrated example, the parts corresponding to the respective parts of the above-described first embodiment will be denoted by the same reference numerals, and their overlapping description will be omitted to distinguish the differences from the first embodiment. I will focus on the explanation.

In this embodiment, a rotary blade 13 'is used instead of the hair clipper blade 13 of the first embodiment, a brake operating member 30' is used instead of the brake operating member 30, and the brake operating member 30 'is used. The remaining structure is the same as that of the first embodiment, except that the handle grip 17 of the handle 16 can be operated and the arrangement position of the compression coil spring 50 is changed.

In this embodiment, the compression coil spring 50 is used.
Is interposed between the annular flange 31 of the driven-side transmission case 23 and the annular flange 49 of the driven-side cover case 11, and the driven-side cover case 11 is moved to the right in FIG. It is urged to move relative to. The operating position in FIG. 8 shows a state in which the driven side cover case 11 is moving to the rightmost position with respect to the driven side transmission case 23, and the driven side cover case 11 moves integrally with the driven side cover case 11. Side clutch plate 46
Is in frictional contact with the friction stopping lining member 32 and is in the brake-in state, the clutch shoe 44 and the driven side clutch plate 46 are separated from each other, and the centrifugal clutch 40
Is in the clutch-out state.

The brake actuating member 30 'has a bolt insertion hole 30'a through which the case fixing bolt 28 is inserted at an intermediate portion.
And a wire attachment portion 30′b for connecting one end of the operation wire 61 to the upper side and an operation claw 30′c on the lower side. The brake actuating member 30 ′ is swingably supported by the case fixing bolt 28 in the insertion hole 29 on the upper side of the driven side transmission case 23. The other end of the operation wire 61 is guided to the handle grip 17 of the handle 16, is connected to an operation lever 62 attached to the handle grip 17, and is operated by the operation lever 62.

Next, the operation of this embodiment will be described.
As described above, in FIG. 8, when the rotary blade type brush cutter 10 ′ is not in operation, the prime mover 14 is rotated and the centrifugal clutch 40 is rotated.
Although the drive side of the motor is rotating, the centrifugal clutch 40 is in the clutch-out state and the driven side is in the brake-in state. Under such a condition, the operator grips the handle grips 17 on the left and right of the handle 16 of the rotary blade type brush cutter 10 ′, and further, the operation lever 62 fixed to the handle grips 17. Hold the handle 1
When the operation wire 61 is pulled while being gripped together with 7, the brake actuating member 30 swings clockwise around the case fixing bolt 28 as an axis. By this swinging, the operating claw 30'c of the brake operating member 30 presses the annular flange 49 of the driven-side cover case 11 to move the driven-side cover case 11 to the left in FIG. By this movement, the compression coil spring 50
Is compressed and the driven side clutch plate 46 comes out of the frictional contact with the friction stopping lining member 32 to bring the brake out state, while the driven side clutch plate 46 frictionally contacts the clutch shoe 44. 40
Put in the clutch-in state. When the centrifugal clutch 40 is in the clutch-in state, the rotary blade 13 'rotates. In such a state, the operator grips the handle grip 17 of the handle 16 to perform the mowing work.

Further, when the motor 14 is stopped at the end of the brush cutting operation, the rotational driving force of the centrifugal clutch 40 is reduced, so that the clutch sliders 42, 42 of the centrifugal clutch 40 are driven by the centrifugal force. The clutch shoe 44 is separated from the driven side clutch plate 46 to release the frictional contact, and the rotary drive of the rotary blade 13 ′ is stopped in the clutch out state.

By the way, the operator can use the rotary blade type brush cutter 1
When the rotary blade 13 ′ comes into contact with some obstacle or the like during the mowing work at 0 ′ and the rotation of the rotary blade 13 ′ is hindered, the prime mover 14 is overloaded. Will end up. In such a state, the operator releases the operation lever 62 of the handle grip 17 to release the operation wire 6
If the traction force of 1 is eliminated, the compression coil spring 50
The driven side cover case 11 moves to the right with respect to the driven side transmission case 23 by the urging force of
Move to the position shown in. By this movement, the driven side clutch plate 46 is separated from the clutch shoe 44 of the centrifugal clutch 40 to be in a clutch-out state, and the rear side surface 46a of the driven side clutch plate 46 makes frictional contact with the friction stopping lining member 32. And brake-in state. By this operation, overload on the side of the prime mover 14 is automatically prevented, and the rotary blade 13 'is fixed.

As described above, in the above two embodiments, since the emergency braking device with the clutch is provided in the middle of the power transmission path of the brush cutter or the like, it seems that the working part is overloaded for some reason. At this time, the clutch can be immediately put into the clutch-out state, and the brake-in state can be set to stop the power transmission to the working portion and fix the cutting blade. Although the two embodiments of the present invention have been described above in detail, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention described in the claims. Can be changed.

For example, in the above-mentioned embodiment, the example in which the emergency brake device with the centrifugal clutch is provided in the middle of the power transmission path to the cutting blade of the brush cutter, is widely used.
Furthermore, the emergency braking device with a centrifugal clutch can be installed in a general power transmission device. Further, the brake actuating member of the first embodiment may be configured to be operated via an operation wire or the like so that it can be operated by the handle grip portion of the handle as in the second embodiment. Further, the centrifugal clutch itself is not limited to the above embodiment, and any structure may be used as long as the driven side clutch plate can move in the rotation axis direction.

[0035]

As can be understood from the above description, according to the present invention, since the emergency brake device with the centrifugal clutch is interposed in the power transmission path of the brush cutter, etc., the centrifugal clutch is in the clutch-in state. Even if power is transmitted to
The clutch-out state can be immediately operated automatically or manually, and at the same time, the driven portion side can be fixed in the brake-in state. Therefore, even if the cutting blade part on the driven part comes into contact with some obstacle or the like and the movement of the cutting blade is hindered, and the overload is applied to the prime mover side, this overload is immediately caused by the operation. It can be avoided and the working part such as the cutting blade can be fixed.

Further, according to the present invention, the contact joint surface between the clutch shoe of the centrifugal clutch and the driven side clutch plate is constructed in the same manner as that of the disc type friction clutch. Since a large surface can be secured, a firm clutch-in state can be secured and the contact bonding surface can be easily processed.

[Brief description of drawings]

FIG. 1 is a perspective view showing an overall outline of a clipper-type brush cutter according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the emergency brake device with a clutch as seen from the direction of arrow II in FIG. 1 in a clutch-out state.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is an exploded perspective view of a driven side transmission case portion.

5 is a vertical cross-sectional view of the emergency brake device with a clutch as seen from the direction of arrow II in FIG. 1 in a clutch-in state.

FIG. 6 is a vertical cross-sectional view of the emergency brake device with a clutch as seen from the direction of arrow II in FIG. 1 in a brake-in state.

FIG. 7 is a perspective view showing an overall outline of a rotary blade type brush cutter according to another embodiment of the present invention.

8 is a vertical cross-sectional view of the emergency brake device with a clutch in a brake-in state as viewed in the direction of arrow VIII in FIG. 7.

[Explanation of symbols]

 10 ... Hair clipper type brush cutter 11 ... Driven side cover case 16 ... Handle 20 ... Emergency brake device 21 ... Transmission case 30 ... Brake actuating member 30 '... Brake actuating member 31 ... Annular flange 31a ... One side of annular flange 32 ... Friction Stopping brake member 40 ... Centrifugal clutch 42 ... Clutch slider 43 ... Drive side braking plate 44 ... Clutch shoe 46 ... Driven side clutch plate 46a ... Driven side clutch plate rear side surface 46b ... Driven shaft 50 ... Compression coil spring (with) 62. Operation lever XX ... Rotation axis

Claims (8)

[Claims] 1. In an emergency braking device 20 in which a centrifugal clutch 40 is installed in a transmission case 21, a drive side braking plate 43 with a clutch shoe 44 of the centrifugal clutch 40 is rotated by a centrifugal force acting on a clutch slider 42. Axis XX
The emergency brake device is arranged so as to slide in the direction of the driven side clutch plate 46 along. 2. A driven shaft 4 which is arranged so that a base end portion of a driven side cover case 11 is movable with respect to the transmission case 21 and which is integrated with the driven side clutch plate 46 of the centrifugal clutch 40.
6b is rotatably supported in the driven-side cover case 11, an urging member 50 is interposed between the driven-side cover case 11 and the transmission case 21, and a rear side surface 46a of the driven-side clutch plate 46. And one side surface 31a of the annular flange 31 of the transmission case 21 facing the rear side surface 46a.
The friction surfaces for and are used as and.
Emergency brake device described. 3. The brush cutter 1 comprises the emergency braking device 20.
The emergency braking device according to claim 1 or 2, wherein the emergency braking device is equipped with 0. 4. The urging member 50 urges the driven-side cover case 11 and the driven-side clutch plate 46 to move in the direction of the drive-side braking plate 43 along the rotation axis XX. The emergency braking device according to any one of claims 1 to 3, which is characterized in that. 5. The two braking frictions of the driven side clutch plate 46 and the annular flange 31 are prevented by preventing the driven side cover case 11 and the driven side clutch plate 46 from moving toward the drive side braking plate 43. The brake actuating member 30 for bringing the centrifugal clutch 40 into a clutch-out state and bringing the centrifugal clutch 40 into a brake-in state by bringing the surfaces 31a and 46a into contact with each other is provided.
Emergency brake device described. 6. The urging member 50 urges the driven-side cover case 11 and the driven-side clutch plate 46 to move in a direction opposite to the drive-side braking plate 43, thereby urging the two braking friction surfaces 31a. , 46a are brought into contact with each other to bring them into a brake-in state. 7. The emergency system according to claim 6, further comprising a brake actuating member 30 ′ for moving the driven-side cover case 11 and the driven-side clutch plate 46 toward the driving-side braking plate 43. Brake device. 8. The emergency brake device according to claim 7, wherein the brake actuating member 30 ′ is operated by an operating lever 62 provided on the handle 16.