JP2002186327A - Bush cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bush cutter with which an increase in the swing amount of a brake arm by abrasion of a brake shoe is absorbed by a fixed distance, consequently, the brake shoe can be used until the thickness of the brake shoe reaches an exchange standard and the operatability can be improved without adjusting the position of a slip-off stopping ball part every time. SOLUTION: This bush cutter comprises a brake mechanism 45 composed of a brake drum 81, a brake arum 82 equipped with a brake shoe 83, a pin 85 fitted to the brake arm, an elastic member 86 for urging the brake arm to a braking side, a brake wire 25 for swinging the brake arm to a brake release side and a brake operation element for pulling the brake wire. The slip-off stopping ball part 33 arranged at one end of the brake wire is installed in a nonoperated state of the brake operation part at a fixed distance S from the brake arm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a brake for stopping rotation of a cutting blade of a brush cutter.

[0002]

2. Description of the Related Art As a brake of a brush cutter, for example, there is one disclosed in Japanese Utility Model Publication No. 57-42261, "Cutter Brake Apparatus in a Brush cutter". According to FIG. 6 of this publication, the cutter brake device
A brake shoe 12 is arranged in contact with the inner periphery of the brake shoe 1, a brake wire 4 is stretched between the brake shoe 12 and the arm 10 (FIG. 2), and the brake wire 4 is pulled back by a brake spring 13. When the arm 10 is not operated, the brake shoe 12 is pressed by the brake spring 13 to apply a brake to the cutter shaft 14.

[0003]

However, in the above structure, if the brake is used for a long time, the brake shoe 12
Is gradually worn away at the position where it is connected to the brake wire 4, and a gap is created between the brake shoe 12 and the brake drum 11. Therefore, the function of the brake is deteriorated, and the brake cannot withstand long-time use. In this case, even if the thickness of the brake shoe 12 is a usable thickness, it is necessary to replace the brake shoe 12, and the frequency of replacing the brake shoe 12 increases, resulting in poor handling. Even if adjustment is possible, it is necessary to adjust each time, and it takes time and effort.

Accordingly, an object of the present invention is to provide a bush cutter capable of improving the handleability of the brake.

[0005]

According to a first aspect of the present invention, a mowing device is driven by a motor to cut weeds and the like, and a brake mechanism is provided in a power transmission system from the motor to the mowing blade. In the brush cutter that can stop the cutting blade by interposing, the brake mechanism includes a brake drum and
A brake arm with a brake shoe, a pin attached to one end of the brake arm, an elastic member for urging the brake arm swinging about this pin toward the braking side, and braking the brake arm against the elastic member A brake wire that swings to the release side, and a brake operating element that pulls the brake wire. After one end of the brake wire passes through the brake arm, the retaining ball provided at one end is in a state where the brake operating element is not operated. And is provided at a certain distance from the brake arm.

The brake arm swings like a balance around a pin. When the brake shoe at one end of the brake arm wears, the other end of the brake arm moves toward the stopper ball by an amount corresponding to the amount of wear. Swing to approach. In this case, since the retaining ball portion is provided at a fixed distance from the brake arm, an increase in the swing amount of the brake arm caused by wear of the brake shoe can be absorbed by this distance. Even so, the other end of the brake arm does not interfere with the retaining ball portion. As a result, the brake shoe can be used until the thickness of the brake shoe reaches the replacement guide without adjusting the position of the retaining ball portion each time, and the handleability of the brake is improved.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals. FIG. 1 is a side view showing a state of use of a brush cutter according to the present invention.
1 shows a state in which the user hangs from the shoulder, grips the operation unit 12 with his hand, and performs a mowing operation. 13 is a cutting blade, and 40 is a prime mover.

FIG. 2 is a side view of the operation unit according to the present invention, showing a partial cross section. The operation unit 12 includes the handle case 2
1 includes a throttle lever 22 swingably mounted to control the rotation speed of the prime mover 40 (see FIG. 1) and a brake operator swingably mounted to brake the cutting blade 13 (see FIG. 1). Of the brake lever 23,
And a kill switch 24 for stopping the prime mover 40. 25 is a brake wire.

The brake wire 25 is made of a steel wire 31.
, A retaining ball portion 33 provided at one end 32, and a retaining ball portion 35 provided at the other end 34. The brake lever 23 includes a cylindrical portion 36 rotatably mounted on the handle case 21, a lever portion 37 extending from the cylindrical portion 36, and a retaining ball portion extending from the cylindrical portion 36 and at the other end 34 of the brake wire 25. Arm part 3 multiplied by 35
8 and a spring 39 that applies a swing force to the brake lever 23 in a direction to release the brake operation. 21a is a stopper portion.

Here, the operation of the brake lever 23 will be briefly described. FIG. 2 shows a state where the brake lever 23 is not operated, and shows a position of the lever portion 37 when the brake lever 23 is not operated. When the lever 37 is manually operated from this position as shown by the arrow, the arm 38 swings and pulls the retaining ball 35 of the brake wire 25 as shown by the arrow, thereby releasing the brake. Conversely, when the lever 37 is released, the arm 39 returns by the spring 39, and the wire 31 returns, and the brake is applied.

FIG. 3 is a detailed view of part 3 of FIG. Brush cutter 1
Reference numeral 0 denotes an operation unit 12 (see FIG. 1), a prime mover 40, and a centrifugal clutch 42 that couples and transmits power when the rotation speed of a crankshaft 41 of the prime mover 40 increases.
A blade driving shaft 43 for transmitting a rotational force;
Blade 13 (see FIG. 1) connected to the centrifugal clutch 4
And a cover 44 that covers the periphery of the motor 2, and a brake mechanism 4
5 is interposed.

The prime mover 40 has a cylinder 51, a piston 52, a crankshaft 41, and a spark plug 54. 55 is a fuel tank, 56 is an oil tank, 57
Is a starting device. The centrifugal clutch 42 has a clutch drum 58 for transmitting the rotational force of the crankshaft 41 to the blade drive shaft 43.
Has a brake drum 81 of the brake mechanism 45 on the outer periphery.

The brake mechanism 45 has the above-described brake wire 25 and a brake arm 82 connected to the brake wire 25 and attached to the cover 44. The brake mechanism 45 will be described in detail with reference to FIGS.

FIG. 4 is a perspective view of a cover according to the present invention. The cover 44 includes a clutch cover 61 and an arm cover 62 attached to the clutch cover 61. The clutch cover 61 has an opening 64 to be attached to the prime mover at one end of a cover body 63, a bottom 65 and a bearing 66 at the other end, and an L-shaped one end 32 of the brake wire 25 on the left side of the bottom 65. A wire guide 67 is formed at the lower left of the bottom 65, and a mounting seat 68 is formed at one end 32 side with the nuts 25a, 25a. An arm mounting boss 71 is provided at the lower right, and a spring is mounted at the upper right. A boss 72 is provided, and bosses 73, 73 formed with female threads for attaching the arm covers 62 to the left and right are provided.

The arm cover 62 has an opening 75 formed in the cover body 74 to be fitted to the clutch cover 61, a wire passing portion 76 formed on the left, and a projection 77 covering the retaining ball portion 33 provided below. An inspection window 78 is formed in the convex portion 77, and mounting holes 79, 79 are opened on the left and right. The inspection window 78 has a transparent resin plate attached so that the retaining ball portion 33 can be seen. The clutch cover 61
Arm mounting boss 71 is a portion that supports the brake arm 82 of the brake mechanism 45 so as to swing freely.

FIG. 5 is an exploded view of the brake mechanism according to the present invention. The brake mechanism 45 includes a brake drum 81 (see FIG. 1), a brake arm 82 having a brake shoe 83, a pin 85 attached to one end 84 of the brake arm 82, and a brake arm that swings around the pin 85. An elastic member 86 for urging the brake arm 82 toward the braking side (in the direction of the arrow); and a brake wire 2 for swinging the brake arm 82 toward the braking release side against the elastic member 86.
5, a brake lever 23 (see FIG. 2) as a brake operator for pulling the brake wire 25, a locking pin 87 for hooking a retaining ball 33 provided at one end 32 of the brake wire 25, and an elastic member 86. It comprises an elastic member hooking pin 88 to be hooked, and a shoe mounting member 89 for mounting the brake shoe 83.

The brake arm 82 has a square pin hole 82a at one end 84, a U-shaped wire mounting portion 82c (plate 82d, plate 82e) at the other end 82b, and a hole formed in the wire mounting portion 82c. 82f and 82g are opened. The pin 85 has, at one end, a quadrangular projection 85a to be attached to the brake arm 82, a shaft 85c to be fitted to the arm attachment boss 71 of the clutch cover 61 via a bush 85b at the center, and a flat surface at the other end. A portion 85d is formed. 85e, 85e are color, 85f
Is screwed into the width across flats 85d, and the shoe mounting member 89
It is a bolt for attaching.

The retaining pin 87 has a U-shaped groove 87a, a groove 87b, and a washer fitting portion 87 through which the steel wire 31 passes in order from the end.
c, a flange 87d is formed. 87e is a retaining ring, 87f is a washer. To assemble these,
First, the locking pin 87 is inserted into the hole 82f of the wire attaching portion 82c.
, The washer 87f is hung on the hooking pin 87, then the wire 31 is inserted into the U groove 87a, the hooking pin 87 is passed through the hole 82g, and finally, the washer 87f is hung on the washer fitting portion 87c. Attach the retaining ring 87e to the groove 87b. Since the width of the U groove 87a is larger than the diameter of the wire 31, the wire 31 can move in the U groove 87a in the arrow direction. Note that the wire 82 can be prevented from coming off by the plate 82e, and the washer 87f and the flange 87
By sandwiching the plate 82d with the d, the retaining pin 87 can be prevented from coming off, and the retaining pin 87 can be pivotally attached.

The elastic member retaining pin 88 has an external thread 88a for screwing into the internal thread of the spring mounting boss 72 of the clutch cover 61. The shoe mounting member 89 has a square hole 89a at the center for fitting into the two-plane width portion 85d,
The pressing portion 89b is provided on one side from the square hole portion 89a, and the spring retaining portion 89c is provided on the other side.

FIG. 6 is a view taken in the direction of arrow 6 in FIG. 4, and includes a brake drum 81, a brake arm 82 having a brake shoe 83, a pin 85 attached to one end 84 of the brake arm 82, and a pin 85 An elastic member 86 for urging the brake arm 82 swinging around the brake arm toward the braking side (in the direction of the arrow), the brake wire 25 for swinging the brake arm 82 toward the brake release side against the elastic member 86, and the brake A brake mechanism 45 including a brake lever 23 (see FIG. 2) as a brake operator for pulling a wire 25 is shown.

The retaining ball portion 33 of the brake wire 25
Is provided at a predetermined distance S from the brake arm 82 without operating the brake lever 23 (see FIG. 2). Specifically, the distance from the retaining ball portion 33 to the hook pin 87 was set to S. The thickness of the brake shoe 83 is
t.

The operation of the bush cutter described above will now be described. FIGS. 7A to 7C are operation diagrams of the brush cutter according to the present invention. In (a), the initial setting of the brake mechanism 45 is such that the thickness of the brake shoe 83 is t, and the distance from the retaining ball 33 of the brake wire 25 to the hook pin 87 is S. The distance S is determined when the brake arm 82 swings around the pin 85 as shown by the arrow by the pulling force F of the elastic member 86 while the brake lever is not operated and the brake shoe 83 presses the brake drum 81 to perform braking. The dimensions. To release the braking from this state, operate the brake lever.

In (b), when the brake lever is operated and the brake wire 25 is pulled as shown by the arrow, the retaining ball portion 33 hits the locking pin 87 of the brake arm 82, and the brake arm 82 is pivoted around the pin 85. Swing toward the brake release side against the elastic member 86 as shown by the arrow. As a result, the brake shoe 83 moves to the brake drum 8
Since it is away from 1, the brake drum 81 can be rotated and the cutting blade can be rotated.
On the other hand, when the brake lever is released, the retaining ball portion 33 returns as shown in FIG.

In (c), when the brake is used for a long period of time, the brake shoes 83 are worn, and in this example, the thickness of the brake shoes 83 is t1. At this time, the distance from the retaining ball portion 33 to the retaining pin 87 is S1, and the brake arm 82 does not interfere with the retaining ball portion 33. As a result, the brake shoe 83 can be applied to the brake drum 81 by the elastic member 86 even at this time point after long-term use, and braking can be performed.

As described above, one end 32 of the brake wire 25
After passing through the brake arm 82, the retaining ball portion 33 provided at one end 32 is provided at a fixed distance S from the brake arm 82 without operating the brake lever. The increase in the swing amount of the brake arm 82 caused by the brake arm 82 can be absorbed, and even if the brake shoe 83 is worn, the brake arm 82 does not interfere with the retaining ball portion 33 and the brake can be applied. As a result, the brake shoes can be continuously used for a long time until the thickness of the brake shoes 83 reaches the replacement standard without adjusting the position of the retaining ball portion 33 each time, and the handleability of the brake is improved. Can be achieved.

Further, as shown in FIG. 2A, since the inspection window 78 is formed in the arm cover 62, the decrease in the distance S can be visually confirmed without removing the arm cover 62. Therefore, the handleability of the brake can be improved.

The form of the brake shoe 83 shown in FIG. 5 according to the embodiment of the present invention is arbitrary, and may be, for example, a band. Further, the forms of the brake drum, the brake arm, and the brake operator are also arbitrary. The formation of the inspection window 78 provided in the arm cover 62 is optional.

[0028]

According to the present invention, the following effects are exhibited by the above configuration. According to the first aspect, the brake mechanism includes a brake drum, a brake arm having a brake shoe, a pin attached to one end of the brake arm, and an elastic member for urging the brake arm swinging about the pin toward the braking side. A brake wire for swinging the brake arm toward the brake release side against the elastic member, and a brake operator pulling the brake wire, and provided at one end after penetrating one end of the brake wire through the brake arm. The retaining ball portion is provided at a certain distance from the brake arm without operating the brake operating element, and the constant distance absorbs an increase in the swing amount of the brake arm due to wear of the brake shoe. As a result, the brake shoe can be used continuously for a long time until the thickness of the brake shoe reaches the replacement guide without adjusting the position of the retaining ball portion each time, and the handleability of the brake is improved. be able to.

[Brief description of the drawings]

FIG. 1 is a side view showing a use state of a brush cutter according to the present invention.

FIG. 2 is a side view of the operation unit according to the present invention.

FIG. 3 is a detailed view of three parts of FIG. 1;

FIG. 4 is a perspective view of a cover according to the present invention.

FIG. 5 is an exploded view of a brake mechanism according to the present invention.

FIG. 6 is a view taken along line 6 of FIG. 4;

FIG. 7 is an operation view of the brush cutter according to the present invention.

[Description of Signs] 13: Cutting blade, 23: Brake operator (brake lever), 25: Brake wire, 33: Retaining ball portion, 4
0: prime mover, 45: brake mechanism, 81: brake drum, 82: brake arm, 83: brake shoe, 8
4: One end of the brake arm, 85: Pin, 86: Elastic member, S: Constant distance.

Continued on the front page (72) Inventor Takao Kobayashi 1-4-1 Chuo, Wako-shi, Saitama Pref. Inside of Honda R & D Co., Ltd. (72) Inventor Jun Kojima 1-4-1 Chuo, Wako-shi, Saitama Co., Ltd. Honda R & D F term (reference) 2B083 AA02 BA02 CA07 CA27 DA02 EA08 GA05 HA22 HA29 3J058 AA03 AA06 AA13 AA17 AA23 AA30 AA37 BA17 CC06 CC66 CC76 CD18 CD27 FA14

Claims (1)

[Claims] A mowing machine capable of mowing weeds and the like by driving a mowing blade with a prime mover and stopping the mowing blade by interposing a brake mechanism in a power transmission system from the prime mover to the mowing blade. The brake mechanism includes a brake drum, a brake arm having a brake shoe, a pin attached to one end of the brake arm, an elastic member for urging the brake arm swinging around the pin toward the braking side, A brake wire that swings the brake arm toward the brake release side against an elastic member; and a brake operator that pulls the brake wire. After penetrating one end of the brake wire through the brake arm, The retaining ball portion provided is provided at a certain distance from the brake arm in a state where the brake operator is not operated. A brush cutter characterized by the following.