JP3489810B2 - Brake device for brush cutter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brush device for a brush cutter.

[0002]

2. Description of the Related Art As a brake device for a brush cutter, for example, Japanese Unexamined Patent Publication No. 50-129319, "Working machine having a cutting blade" is known. The above-mentioned technique positively applies a braking force to the cutting blade side when the power transmission to the cutting blade is removed so as to prevent the cutting blade from swinging due to inertia. As shown in FIGS. 3, 3 and 4, the operating rod 3 passed between the engine 2 and the cutting blade 7, the transmission shaft 5 provided in the operating rod 3, and the end of the transmission shaft 5. The driven side element 1c attached to the parts, the brake shoes 8 and 8 for pressing the driven side element 1c to perform braking, and the brake shoes 8 and 8 mounted on the upper portion of the clutch case 1a for moving the brake shoes 8 and 8. Leverage 10 and this Leverage 10
And a brake wire 13 connected to the.

[0003]

In the above technique, the lever 10 and the brake wire 13 for operating the brake are provided.
Is disposed above the clutch case 1a, the lever 10 and the brake wire 13 come into contact with the arm and the body during the brush cutting operation, which is an obstacle to the operation. Therefore, an object of the present invention is to provide a braking device for a brush cutter that does not hinder work and improves workability.

[0004]

In order to achieve the above object, the first aspect of the present invention is to attach a clutch case to the front part of the engine, extend the operating rod forward from the clutch case, and to the tip of the operating rod. The cutter is arranged, the brake lever is attached to the operating rod, the transmission shaft for transmitting the driving force to the cutter is stored in the operating rod, and the centrifugal clutch for interrupting the driving force transmitted from the engine to the transmission shaft is stored in the clutch case. However, a clutch drum that also functions as a brake drum for braking the cutter is provided on the transmission shaft side of this centrifugal clutch, a support shaft is provided near this clutch drum, and an arm is attached to this support shaft so that it can swing. Attach a brake shoe that presses against the clutch drum at one end,
Met brake device of the bush cutter coupled to the brake wire to the other end of the arm, together with Sowaseru the outer surface of most of the operating rod of a brake wire, the outer surface facing away from the operator than the vertical center line of the operating rod Brake device for the installed brush cutter
At the operator side from the vertical center line of the operating rod.
Also, it is provided below the horizontal center line and connects the brake wire.
The brake wire attachment part of the arm
Opposite the operator from the center line and below the horizontal center line
Placed in. The work is improved because the work is not disturbed by the brake wire. Also, since the support shaft is below the horizontal center line of the operating rod, the brake arm and brake shoe can be arranged below the operating rod, and the center of gravity of the brush cutter is lowered, so that the operability of the brush cutter is reduced. improves. Furthermore , the spindle is
The worker side near than the vertical center line of the operating rod is, moreover, shake
-The key wire attachment part is located on the operator's rod with respect to the vertical center line.
Opposite side near because, can lengthen opposite the operator from the vertical center line of the operating rod arm, operation force of the brake lever is reduced.

According to a second aspect of the present invention, a spring for pressing the brake shoe to the clutch drum is attached to the arm, and a portion from the arm support shaft to the brake wire attachment portion serves as a first arm portion, and the arm support shaft to the brake shoe attachment portion. Up to the second arm part, and from the arm support shaft to the spring mounting part to the third arm part, the second arm part and the third arm part are brought close to each other, and the arm is substantially Y-shaped by these three arm parts. Formed into a shape. By forming the arm in a substantially Y shape, the brake device becomes compact, the brush cutter itself becomes small, and the operability of the brush cutter is improved.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of the reference numerals. FIG. 1 is a side view showing a state in which a brush cutter provided with a brake device according to the present invention is in use, in which an operator M suspends the brush cutter 1 from a shoulder with a hanging belt 2 and grasps an operating lever device 10. The state of performing the reaping work is shown.

The brush cutter 1 includes an engine 3, a cutter 4 driven by the engine 3, an operating rod 5 as an operating rod passed between the engine 3 and the cutter 4, and an engine 3 in the operating rod 5. It comprises a transmission shaft 6 housed for transmitting the driving force of the above to the cutter 4, a handle bar 7 attached to the operation rod 5, a grip 8 attached to the handle bar 7 and the above-mentioned operation lever device 10.

FIG. 2 is a perspective view of the operating lever device of the brush cutter according to the present invention. The operating lever device 10 controls the handle case 11 and the rotation speed of the engine 3 (see FIG. 1) in the handle case 11. In order to control the braking state of the cutter 4 (see FIG. 1) on the handle case 11, the throttle lever 12 is swingably mounted on the handle case 11, and the throttle lever 12 is used to close the throttle. Throttle return lever 14 provided to push back to the engine side and the engine 3
And a kill switch 15 for stopping. The handle case 11 includes an upper case 18 including left and right cases 16 and 17, and a lower case 19 that also serves as a grip.

FIG. 3 is a vertical cross-sectional view of the operating lever device of the brush cutter according to the present invention. The operating lever device 10 includes a throttle wire 22 connected to an end of a throttle lever 12.
The brake wire 23 connected to the end of the brake lever 13, the throttle lever 12 and the brake lever 13
And a cam member 24 disposed between

The throttle lever 12 is the upper case 1.
8, a cylindrical portion 12a rotatably attached to the first shaft portion 18a, and a lever portion 1 extended from the cylindrical portion 12a.
2b and a substantially fan-shaped plate-shaped portion 12c, an arc-shaped long hole 12d formed in the plate-shaped portion 12c, and a throttle return lever 14
(See FIG. 2) The screw part 12e is formed by welding a nut to fix the screw part (see FIG. 2), and the contact surface 12f is formed on the lever part 12b to contact the cam member 24.

The brake lever 13 has an upper case 18
The cylindrical portion 13a rotatably attached to the second shaft portion 18b formed on the first shaft portion 18b, and the lever portion 13 extended from the cylindrical portion 13a.
b and the arm portion 13c. Throttle wire 2
2 and the brake wire 23 are used for the engine 3 (see FIG. 1).
It is pulled from the side and passed through the handlebar 7 from the middle. The cam member 24 includes a throttle lever stopper portion 24a that restricts a swing toward the opening side of the throttle lever 12 by contacting the contact surface 12f of the throttle lever 12.

Reference numeral 18c denotes an upper case 18 for restricting a counterclockwise swing of the brake lever 13.
18d is a spring stopper provided on the left case 16, 25 is a spring that gives the throttle lever 12 a swinging force in the rotational direction toward the throttle closing side, and 26 is a brake lever 13 that releases the brake operation. It is a spring that gives a swinging force in the direction of movement.

FIG. 4 is a cross-sectional view of the operating lever device of the brush cutter according to the present invention. The operation lever device 10 includes friction washers 27 and 28 and disc springs 31 and 32 arranged to sandwich the plate-shaped portion 12c of the throttle lever 12 on the side of the cam member 24 (downward in the drawing), and the cam members 24. , Friction washers 27, 28 and disc spring 3
1 and 32 are penetrated, and a hexagon socket head cap screw 34 fixed to the right case 17 with a screw member 17a and a cap nut 33 to be provided on the right case 17. 35, 36,
37 is a washer and 38 and 38 are case assembling bolts.

The slot lever 12 is provided with a throttle wire attachment portion 12g at the end of the plate-like portion 12c, and the throttle wire 22 is attached to the throttle wire attachment portion 12g.
The wire end stopper 22a (see FIG. 3) is attached. The brake lever 13 includes a brake wire attachment portion 13d and a column portion 13e at an end of the arm portion 13c, and the brake wire 2 is attached to the brake wire attachment portion 13d.
3 (see FIG. 3) is attached to the wire tip stopper 23a. The right case 17 includes a cam portion 17b that is in contact with the cam member 24. The cam member 24 includes an elongated hole 24c for connecting with the arm portion 24b and the column portion 13e of the brake lever 13.

The friction washers 27, 28 generate a frictional force by pressing them against the plate-like portion 12c of the throttle lever 12, and rubber is preferable as a material. The disc springs 31 and 32 are the friction washers 2
This is to obtain a load for pressing 7, 28.

The hexagon socket head cap screw 34 changes the role of the shaft of the cam member 24 and the amount of flexure of the disc springs 31 and 32 when the disc springs 31 and 32 are attached to change the load generated by the disc springs 31 and 32. It also serves as a pressing load adjusting member that changes the load when pressing the friction washers 27 and 28 against the plate-shaped portion 12c.

That is, when the hexagon socket head cap screw 34 is, for example, a right-hand screw, by turning it clockwise, the heads 34a of the hexagon socket head cap screw 34 cause the disc springs 31 and 32 to largely bend, thereby increasing the pressing load. By turning counterclockwise, disc springs 31 and 3
The bending load of 2 is reduced to reduce the pressing load. The same applies to the case of the left-hand thread.

The arm portion 1 of the brake lever 13 described above.
3c and the cylindrical portion 13e, the cam member 24, the cam portion 17b of the handle case 11, the friction washer 2
7, 28, disc springs 31, 32, and hexagon socket head cap screw 3
4 and 4 constitute a throttle restraint mechanism 39.

FIG. 5 is a perspective view showing the cam member of the brush cutter and the cam portion of the handle case according to the present invention. The cam portion 17b of the handle case 11 (see FIG. 2) is the cam surface 17
c crest 17d ... (... indicates a plurality, and so on.)
Equipped with. The cam crest 17d includes a slope 17e. The cam member 24 has a cam surface 1 of the cam portion 17b on the bottom of the recess 24d.
The cam groove 24f is provided with a cam surface 24e facing the 7c, and the cam crests 17d of the cam portion 17b are engaged with the cam surface 24e.
And a flat surface 24g. The cam groove 24f includes a slope 24h.

When the cam member 24 rotates with respect to the cam portion 17b, the inclined surface 17e of the cam member 17b moves while the inclined surface 24h of the cam member 24 is in contact with the inclined surface 17e of the cam member 17b. Move in the direction. That is, in FIG. 4, the cam member 24 rotates to move in the axial direction of the hexagon socket head cap screw 34 (the vertical direction in the drawing).

FIG. 6 is a sectional view taken along line 6-6 of FIG. 1, showing a clutch case 1 attached to the front portion of the engine 3 (see FIG. 1).
It shows that the brake device 40 is provided in a. The drum 41 having the function of a brake drum that constitutes the brake device 40 has a transmission shaft 6 through a shaft portion 41a attached to the front portion.
It is connected to. The drum 41 is a clutch drum on the driven side of the centrifugal clutch that connects and disconnects the driving force between the engine 3 and the transmission shaft 6. Here, 1b is a bearing,
Reference numeral 1c is an operation rod attachment member for attaching the operation rod 5 to the front portion of the clutch case 1a.

FIG. 7 is a sectional view taken along line 7-7 of FIG. 1, showing a braking device 40 provided in front of the engine 3 (see FIG. 1) in a braking state. The brake device 40 is the drum 4 described above.
1, a brake shoe 42 that stops the rotation of the cutter 4 (see FIG. 1) by circumscribing the drum 41, a brake arm 43 for moving the brake shoe 42, and an end portion of the brake arm 43. The connected brake wire 23 and the brake shoe 42 on the drum 41.
Tension coil spring 44 that generates load to press
And a brake lever 13 (see FIG. 3).

The brake arm 43 is the clutch case 1
The brake arm shaft 45 is attached to the brake arm shaft 45 so as to be swingable, and the first arm portion 43b from the brake arm shaft 45 to the brake wire attachment portion 43a connecting the brake wire 23 and the brake arm shaft 45 to the brake shoe. Second arm portion 43 up to the mounting portion of 42
c and a third arm portion 43d from the brake arm shaft 45 to the attachment portion of the tension coil spring 44,
The second arm portion 43c and the third arm portion 43d are formed in a substantially Y shape by bringing them close to each other.

First arm portion 43b of the brake arm 43
, That is, the distance L1 from the brake arm shaft 45 to the brake wire mounting portion 43a, and the third arm portion 43d.
Value of the distance from the brake arm shaft 45 to the mounting portion of the tension coil spring 44 and the distance L3 is 2
Over.

The brake arm shaft 45 is provided on the operator M (see FIG. 1) side (right side in FIG. 7) of the vertical center line VL of the operating rod 5 and below the horizontal center line HL. Here, 1d is a spring hooking portion, 1e is a brake wire supporting portion, and 23b is a wire tip stopper of the brake wire 23.

As described above, the brake arm 43 is substantially Y-shaped.
By forming the shape of the character, the brake device 40 can be made compact, the brush cutter 1 (see FIG. 1) itself can be made small, and the operability of the brush cutter 1 can be improved.

If the ratio of the length of the first arm portion 43b to the length of the third arm portion 43d is set to 2 or less,
The operating force of the brake lever 13 (see FIG. 3) becomes large, and, for example, when performing work for a long time, the fatigue of the hand holding the brake lever 13 becomes large, but in the present invention, the ratio value exceeds 2 With this setting, the operating force of the brake lever 13 becomes smaller, and the fatigue of the hand can be reduced.

Furthermore, since the brake arm shaft 45 is located below the horizontal center line HL of the operating rod 5, the brake shoe 42 and the brake arm 43 with respect to the operating rod 5.
Can be arranged below the brush cutter 1, and the brush cutter 1
Since the center of gravity can be lowered, the operability of the brush cutter 1 can be improved.

Furthermore, since the brake arm shaft 45 is located closer to the operator M than the vertical center line VL of the operating rod 5,
The brake arm 43 can be extended longer than the vertical center line VL of the operation rod 5 on the side opposite to the operator M, and the operation force of the brake lever 13 (see FIG. 3) can be reduced.

FIG. 8 is a plan view for explaining the arrangement of the brake wires of the brake device according to the present invention. Most of the brake wires 23 are put on the outer surface 5a of the operating rod 5 of the brush cutter 1, and the operating rod 5 is used. Is arranged on the outer side surface 5b (see FIG. 7) farther from the worker M than the vertical center line VL (see FIG. 7), that is, on the surface opposite to the worker M with respect to the center line S of the operating rod 5. Indicates that you have done. As a result, the arm or body of the worker M does not come into contact with the brake wire 23 during the mowing work, and there is no hindrance to the work, so that workability can be improved.

The operation of the operation lever device 10 described above will be described below. First, in FIG. 3, the brake lever 1
The engine 3 (see FIG. 1) is started without grasping 3. At this time, the throttle lever 12 is regulated by the cam member 24 to the position where the throttle is closed most, so that the engine 3 is in the idling state. Also, FIG.
Since the brake device 40 is in the braking state in which the brake shoe 42 pushes the drum 41, the cutter 4 (see FIG. 1) does not operate even when the engine 3 starts.

9A and 9B are action diagrams (first action diagram) for explaining the action of the brake device according to the present invention.
(A) shows a longitudinal sectional view, and (b) shows a transverse sectional view. In (a), in order to start the work, first, the brake lever 13 is received and grasped by the flat side of the hand H. By gripping the brake lever 13, the arm portion 13c of the brake lever 13 swings clockwise around the second shaft portion 18b, and the arm portion 13 pulls the brake wire 23.

At this time, since the column portion 13e of the arm portion 13c shown in FIG. 4 is in a state of being inserted into the elongated hole 24c formed in the arm portion 24b of the cam member 24, the arm portion shown in FIG. 9 (a). With the swing of 13c, the cam member 24
Rotates counterclockwise around the hexagon socket head cap screw 34 as an axis, and the throttle lever stopper portion 24a of the cam member 24 is disengaged from the contact surface 12f of the throttle lever 12 to release the position regulation of the throttle lever 12. . Therefore, the throttle lever 12 can swing.

In FIG. 9B, when the cam member 24 rotates, the cam member 24 moves in the axial direction with respect to the cam portion 17b as described in FIG. 5, so that the disc spring 31 shown in FIG. , 32 are bent into a substantially flat plate shape, a large load is generated, and the plate-like portion 12c of the throttle lever 12 is pressed by the friction washers 27, 28.
A large frictional force is generated between the 2c and the friction washers 27, 28 to restrain the swing of the throttle lever 12.

If the operating force of the throttle lever 12 is too large, the hexagon socket head cap screw 34 is turned to reduce the flexure of the disc springs 31 and 32, so that the plate-shaped portion 12c and the friction washers 27 and 28 are separated from each other. The frictional force between them becomes small, and the operating force can be made small.

FIG. 10 is an operation diagram (second operation diagram) for explaining the operation of the brake device according to the present invention. When the arm portion 13c of the brake lever 13 shown in FIG. 9 (a) pulls the brake wire 23. , The brake arm 43 shown in FIG.
Swings clockwise around the brake arm shaft 45 against the tensile force of the tension coil spring 44, the brake shoe 42 separates from the drum 41, and the braking is released. Therefore, the cutter 4 (see FIG. 1) can be operated.

FIG. 11 is a cross-sectional view showing another embodiment of the brake device according to the present invention. The same components as those of the embodiment shown in FIG. 7 are designated by the same reference numerals and detailed description thereof will be omitted. The brake device 50 includes a drum 41, a brake shoe 42, a brake arm 53 for moving the brake shoe 42, a brake wire 23 connected to an end of the brake arm 53, a tension coil spring 44, and a brake. The lever 13 (see FIG. 3).

The brake shoe 42 is provided on the side farther from the operator M (see FIG. 1) than the vertical center line VL of the operating rod 5 (left side in the figure) and below the horizontal center line HL. The brake arm 53 is the engine 3 (see FIG. 1).
The brake arm shaft 55 mounted on the front clutch case 50a is swingably mounted, and the first arm portion 53b from the brake arm shaft 55 to the brake wire mounting portion 53a connecting the brake wire 23, and
The second arm portion 53c from the brake arm shaft 55 to the mounting portion of the brake shoe 42, and the brake arm shaft 55
To the mounting portion of the tension coil spring 44, the third arm portion 53d is formed, and the second arm portion 53c and the third arm portion 53d are brought close to each other to form a substantially Y shape.

The brake wire attachment portion 53a is provided on the side farther from the operator M (left side in the figure) than the vertical center line VL of the operation rod 5. Further, the brake wire 23 connected to the brake wire attachment portion 53a is taken out from the clutch case 50a on the side farther from the operator M than the vertical center line VL of the operation rod 5, and the operator M from the vertical center line VL of the operation rod 5. It is arranged on the outer side surface 5b (see FIG. 7) on the side farther from.

The brake arm shaft 55 is provided on the side farther from the operator M than the vertical center line VL of the operating rod 5 (on the left side in the drawing) and below the horizontal center line HL. Here, 23b is a wire end stopper of the brake wire 23,
50b is a spring hook portion, and 50c is a brake wire support portion.

As described above, the brake arm 53 is substantially Y-shaped.
By forming the shape of the character, the brake device 50 can be made compact, the brush cutter 1 (see FIG. 1) itself can be made small, and the operability of the brush cutter 1 can be improved. Further, for example, when the hand is released from the brake lever 13 in order to interrupt or finish the work, the drum 41 connected to the cutter 4 (see FIG. 1) rotating by inertia.
Although heat and noise are generated when the brake shoe 42 is braked by the brake shoe 42, the brake shoe 42 is on the side farther from the worker M than the vertical center line VL of the operation rod 5 and below the horizontal center line HL. M is less susceptible to the heat and sound described above.

The brake device 40 of the present invention is another working machine of the type shown in FIG. 7 in which the drum 41 is held by the brake shoe 42 attached to the brake arm 43, for example, a lawn mower, It can be used for plane cutting machines (hedge trimmers), etc.

[0043]

The present invention has the following effects due to the above configuration. In the brake device of claim 1, most of the brake wire is attached to the outer surface of the operating rod, and is arranged on the outer surface of the operating rod that is farther from the operator than the vertical center line.
Since the brake wire does not touch the arm or the body during the brush cutting work and the work is not disturbed, the workability of the brush cutter can be improved. Further, since the support shaft is provided on the operator side of the vertical center line of the operating rod and below the horizontal center line, the supporting shaft is below the horizontal center line of the operating rod, so that the brake arm is attached to the operating rod. The brake shoes can be arranged further downward, the center of gravity of the brush cutter can be lowered, and the operability of the brush cutter can be improved. Change
The operator side near from the vertical center line of the support shaft is the operating rod is, blanking
The rake wire mounting part is located at a position closer to the operator than the vertical center line of the operating rod.
Opposite side near because, can lengthen opposite the operator from the vertical center line of the operating rod of the arm, it is possible to reduce the operating force of the brake lever. Therefore, it is possible to reduce the fatigue of the operator even when working for a long time.

According to a second aspect of the present invention, there is provided a braking device in which the arm is first
The brake device is compact because it is composed of an arm portion, a second arm portion, and a third arm portion, and the second arm portion and the third arm portion are brought close to each other and these three arm portions are formed into a substantially Y shape. Therefore, the brush cutter itself can be downsized, and the operability of the brush cutter can be improved.

[Brief description of drawings]

FIG. 1 is a side view showing a state in use of a brush cutter provided with a brake device according to the present invention.

FIG. 2 is a perspective view of an operating lever device of the brush cutter according to the present invention.

FIG. 3 is a vertical sectional view of an operating lever device according to the present invention.

FIG. 4 is a cross-sectional view of the operating lever device of the brush cutter according to the present invention.

FIG. 5 is a perspective view showing a cam member of a brush cutter and a cam portion of a handle case according to the present invention.

6 is a sectional view taken along line 6-6 of FIG.

7 is a sectional view taken along line 7-7 of FIG.

FIG. 8 is a plan view illustrating the arrangement of brake wires of the brake device according to the present invention.

FIG. 9 is an operation diagram (first operation diagram) for explaining the operation of the brake device according to the present invention.

FIG. 10 is an operation diagram (second operation diagram) for explaining the operation of the brake device according to the present invention.

FIG. 11 is a sectional view showing another embodiment of the brake device according to the present invention.

[Explanation of symbols]

1 ... brush cutter, 1a ... clutch case, 3 ... engine, 4
... cutter, 5 ... operating rod (operating rod), 5a ... outer surface of operating rod, 5b ... outer surface of operating rod, 6 ... transmission shaft, 13 ... brake lever, 23 ... brake wire, 40, 50 ... braking device, 41 … Drums (clutch drums), 42…
Brake shoe, 43, 53 ... Arm (brake arm), 43a, 53a ... Brake wire mounting portion, 43
b, 53b ... 1st arm part, 43c, 53c ... 2nd arm part, 43d, 53d ... 3rd arm part, 44 ... Spring (tensile coil spring), 45, 55 ... Support shaft (brake arm shaft), M ... Worker, HL ... Horizontal center line, VL
… Vertical centerline.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsushi Kojima 1-4-1 Chuo, Wako-shi, Saitama Inside Honda R & D Co., Ltd. (56) Reference JP-A-9-163849 (JP, A) JP-A 6-62637 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) A01D 34/68 F16D 49/00 F16D 65/30

Claims (2)

(57) [Claims] 1. A clutch case is attached to the front of the engine.
Extend the operating rod forward from this clutch case,
Place the cutter on the tip of the operating rod of the
Install a lever to drive the cutter inside the operating rod.
The transmission shaft for transmitting the
To interrupt the driving force transmitted from the engine to the transmission shaft
The centrifugal clutch is stored and the transmission shaft side of this centrifugal clutch
Also functions as a brake drum for braking the cutter.
A latch drum is provided, and a spindle is installed near this clutch drum.
Is installed, and an arm is attached to this support shaft so that it can swing.
Brake system that presses against the clutch drum at one end of the arm
Mount and connect the brake wire to the other end of the arm.
Brake device for brush cutterAnd Most of the brake wire is attached to the outer surface of the operating rod.
And is farther from the operator than the vertical center line of the operating rod.
Placed on the outer sideMowedBrake equipmentAt Install the support shaft on the operator side from the vertical center line of the operating rod and
Provided below the flat center line, Connect the brake wire
The brake wire attachment part of the arm
On the side opposite the worker from the direct center line and below the horizontal center line
Placed towardsCharacterized byRu cuttingBraking device for the dispenser. 2. A spring for pressing the brake shoe against a clutch drum is attached to the arm, and a portion from the spindle of the arm to the brake wire attachment portion is a first arm portion, and the spindle of the arm supports the brake shoe. The second arm part extends to the attachment part, and the third arm part extends from the arm support shaft to the spring attachment part. The second arm part and the third arm part are brought close to each other to form an arm. brake device of the bush cutter of claim 1 Symbol mounting characterized by being formed into a substantially Y-shape.