JP4676842B2 - Brush cutter - Google Patents

Description

  The present invention relates to a brush cutter.

  2. Description of the Related Art Conventionally, a brush cutter that drives a cutting blade by a rotational driving force of a power unit is known. (For example, refer to Patent Document 1).

  In the device disclosed in Patent Document 1, a power unit provided with an engine and a gear housing provided with a cutting blade are connected by an outer pipe provided with a transmission shaft, and the power of the engine is connected via the transmission shaft. Is a brush cutter that is rotated by being transmitted to the cutting blade. A covering body through which the outer pipe is inserted is provided in front of the power unit of the brush cutter. At the front end (cutting blade side) of the covering body, a joining piece that is fixed in a state in which the outer pipe is inserted protrudes, and the rear side (engine side) of the covering body is connected to the inserted outer pipe. A vibration isolator is provided between them.

Japanese Utility Model Publication No. 60-185424 (see pages 3 to 6, see FIGS. 1 and 2)

  By the way, in the conventional structure like patent document 1, the outer pipe is fastened and fixed by the joining piece which protrudes to the front end of a covering. For this reason, stress concentrates on the contact portion between the joining piece and the outer pipe, and the outer pipe may be damaged or broken.

  It is an object of the present invention to provide a brush cutter that can favorably prevent the outer pipe from being detached, broken or broken.

A brush cutter according to claim 1 of the present invention includes an outer pipe having a cutting blade mounting portion provided at one end and a power portion provided at the other end, and a housing connecting the outer pipe and the power portion. A housing, wherein the housing is formed in a cylindrical shape that is coaxial with an axial direction of the outer pipe and a housing main body fixed to the power unit, and the housing main body is inserted in the outer pipe. A clamp member housed in the clamp member, and the clamp member includes a linear slit formed across the axial end portions and a pair of fixed members provided at positions sandwiching the slit. And the pair of fixed pieces is a region between both end portions in the axial direction of the clamp member, and these fixed pieces are close to each other. By tightening direction, characterized in that provided in the dispersible located towards the stress by tightening the two-way both end sides in the axial direction of the clamping member.

  The brush cutter according to claim 2 of the present invention is characterized in that in the brush cutter according to claim 1, the clamp member is entirely housed in the housing body.

According to the present invention, the housing body is a part which is accommodated in the housing body of the clamp member, the pair of fixing tabs provided in a region between the ends of the axial direction of the clamp member Tighten and pinch the outer pipe . At this time, since the stress acting on the outer pipe is dispersed in the axial direction of both ends bidirectional, thereby preventing damage or Setsuson due to stress of the outer pipe.

  According to the second aspect of the present invention, since the entire clamp member is provided in the housing body, the clamp member does not protrude in front of the housing body, and the axial length of the housing can be shortened. Accordingly, the mounting position of the grip or the like provided in front of the housing by the shortened length can be disposed close to the power unit side, and the influence of the weight of the power unit can be reduced. Operability can be improved.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is an overall perspective view showing the brush cutter according to the present embodiment. FIG. 2 is a perspective view of the mounting housing of the present embodiment. FIG. 3 is a side view of the mounting housing of the present embodiment. FIG. 4 is a cross-sectional view of the mounting housing according to the present embodiment taken along the axial direction.

  In FIG. 1, a brush cutter 1 is configured to drive a not-illustrated cutting blade or nylon cutter attached to an attachment portion 3 on the other end side by a power portion 2 provided on one end side of an outer pipe 1A. A shaft for transmitting power from the power unit 2 is inserted into the pipe 1A. A loop handle 4 and a grip 5 that are gripped by an operator are provided in the middle of the outer pipe 1A.

  The power unit 2 provided at the other end of the outer pipe 1A includes an engine (not shown) covered with a plurality of covers. A mounting housing 6 for connecting the outer pipe 1A is fixed to the power unit 2, and a centrifugal clutch is connected to the drive shaft of the engine. The configuration of the mounting housing 6 will be described later.

  The centrifugal clutch is rotated by the driving force of the engine and transmits the rotational driving force to the clutch drum 21 at a predetermined rotational speed or higher. The clutch drum 21 is provided with a drive transmission shaft 22 that is received by a bearing 611 in the mounting housing 6, and a shaft hole 221 is formed in the drive transmission shaft 22 along the central axis. The shaft is fitted and fixed in the shaft hole 221, and the driving force of the engine is transmitted to the shaft via the centrifugal clutch, so that the shaft rotates.

  The grip 5 is mounted on the outer pipe 1 </ b> A adjacent to the mounting housing 6. The grip 5 is provided at a position to be gripped when the operator operates the brush cutter 1, and the weight of the power unit 2 can be supported by gripping the grip 5. Further, an accelerator lever 7 that performs an output operation of the power unit 2 while holding the safety lever 8 is provided in the vicinity of the grip 5.

[Configuration of mounting housing]
Next, the mounting housing 6 for mounting the outer pipe 1A to the power unit 2 will be described in detail.

  2 to 4, the mounting housing 6 fixed to the power unit 2 includes a housing main body 61 formed in a substantially cylindrical shape, and a clamp member 62 provided on the inner peripheral side of the housing main body 61.

  The housing body 61 is fixed to, for example, a crankcase constituting the engine of the power unit 2 by bolting or the like. The clutch drum 21 described above is accommodated in the opening of the housing body 61 on the power unit 2 side. In the housing main body 61, the above-described bearing 611 that receives the drive transmission shaft 22 of the clutch drum 21 is provided, and the drive transmission shaft 22 is rotatably held. A snap ring 63 is fitted in the opening on the grip 5 side of the housing body 61 along the inner peripheral surface.

  In addition, a pair of communication holes 61A and 61B communicating between the outside and the inside are formed at different positions on the side surface of the housing body 61.

  The clamp member 62 is formed in a substantially cylindrical shape. In a part of the peripheral surface of the clamp member 62, a linear slit 621 is formed across both ends of the cylinder. A pair of fixed pieces 622 that are opposed to each other across the slit 621 are provided at substantially the center position of the slit 621. A bolt tightening hole 623 is formed in the fixed piece 622 at a position corresponding to one communication hole 61A of the housing body 61, and the communication is performed in a state where the outer pipe 1A is inserted into the cylinder of the clamp member 62. The bolt 623A is inserted into the bolt fastening hole 623 from the hole 61A, and the fixing pieces 622 facing each other are fastened to sandwich the outer pipe 1A.

  In addition, another bolt fastening hole 624 is formed at a position corresponding to the other communication hole 61 </ b> B of the housing main body 61 on the peripheral surface of the clamp member 62. The outer pipe 1A is also formed with screw holes (not shown) at positions facing the communication holes 61B and the bolt tightening holes 624, and the bolts 624A inserted into the bolt tightening holes 624 through the communication holes 61B are screwed. The outer pipe 1A is positioned so as not to come out of the clamp member 62 by being screwed into the hole.

  Further, an annular vibration isolator 64 is provided between the clamp member 62 and the housing body 61 on the power unit 2 side and the grip 5 side with the fixed piece 622 interposed therebetween, and is in close contact with the clamp member 62 and the housing body 61. is doing. The vibration isolator 64 is formed of an elastic member such as synthetic rubber, for example, and prevents the clamp member 62 from vibrating and holds the clamp member 62 in the housing body 61. In addition, the width dimension of the vibration isolator 64 provided on the power unit 2 side with the fixed piece 622 interposed therebetween is approximately the same as the width dimension of the vibration isolator 64 provided on the grip 5 side. A positioning projection 625 projecting in the radial direction is formed on the outer peripheral surface of the clamp member 62 in the circumferential direction, and the vibration isolator 64 has a ring-shaped fitting portion that engages with the positioning projection 625. 641 is formed. The vibration isolator 64 is positioned with respect to the clamp member 62 by the positioning protrusion 625 and the fitting portion 641.

  An annular backup ring 65 made of metal is provided between the vibration isolator 64 and the snap ring 63 fixed to the housing body 61 on the grip 5 side. That is, the backup ring 65 allows the vibration isolator 64 and the clamp member 62 to be satisfactorily pressed by the snap ring 63, and reliably prevents it from coming out of the housing body 61.

[Effects of Embodiment]
As described above, in the brush cutter 1 of the present embodiment, the fixing pieces 622 that are opposed to each other are provided at substantially the center positions of the slits 621 that are formed across the both ends of the clamp member 62. The clamp member 62 is tightened at a position corresponding to 622. For this reason, the operator can clamp the clamp member 62 from the outside of the housing body 61 at a substantially central position in the axial direction of the clamp member 62, and can clamp the outer pipe 1A. Therefore, by tightening the fixing piece 622 provided at such a position, the stress acting on the outer pipe 1A can be dispersed, and damage or cutting of the outer pipe 1A due to excessive stress concentration can be prevented.

  The clamp member 62 is housed in the housing body 61 so that the end portion does not protrude from the end portion of the housing body 61. For this reason, the dimension of the axial direction of the mounting housing 6 can be made small. Accordingly, the grip 5 can be brought closer to the power unit 2 as the axial dimension of the mounting housing 6 becomes smaller. By gripping such a grip 5, the influence of the weight of the power unit 2 can be reduced. Therefore, the brush cutter 1 can be handled with good balance, and the operability can be improved.

  Further, since the vibration isolator 64 is provided in parallel along the axial direction, the vibration isolator 64 can be closely attached to the housing main body 61 and the clamp member 62 in a large area. The vibration characteristics can be further improved, and the clamp member 62 can be reliably held in the housing body 61 by friction with the inner peripheral surface of the housing 61.

[Modification of Embodiment]
Note that the present invention is not limited to the above-described embodiment, and includes the following modifications as long as the object of the present invention can be achieved.

  For example, in the above-described embodiment, the fixed piece 622 is provided at a position where the vibration isolator 64 is divided into two equal parts, but the present invention is not limited thereto. The position where the fixing piece 622 is provided may be slightly shifted to the power unit 2 side or the grip 5 side as long as stress concentration does not easily occur.

  In addition, although the example in which the vibration isolator 64 is arranged on the power unit 2 side and the grip 5 side of the fixed piece 622 is shown, both anti-vibration bodies 64 are provided at portions other than the formation position of the fixed piece 622 of the clamp member 62. It is good also as a structure by which the vibrating body 64 was connected and formed integrally. With such a configuration, the vibration-proof property can be further improved.

  Furthermore, although the example in which the screw hole is formed in the outer pipe 1A so as to face the bolt fastening hole 624 of the clamp member 62 is shown, the outer pipe 1A may have a configuration in which no screw hole is formed. For example, it is good also as a structure which inserts a volt | bolt from a clamp side positioning hole, and positions by pressing the outer pipe 1A.

  And although the example in which a pair of fixed piece 622 is formed in the approximate center position of the clamp member 62 was shown, it is good also as a structure by which multiple pairs of fixed pieces 622 are formed. For example, two pairs of fixing pieces 622 may be provided along the slit 621. With such a configuration, the outer pipe 1A can be fixed more reliably.

  In addition, the specific structure and procedure for carrying out the present invention can be changed as appropriate to other structures and the like within the scope of achieving the object of the present invention.

  The present invention can be used for a brush cutter in which a power unit is provided at one end of an outer pipe.

1 is an overall perspective view of a brush cutter according to an embodiment of the present invention. The perspective view of the mounting housing of this embodiment. The side view of the mounting housing of this embodiment. Sectional drawing of the mounting housing of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Brush cutter, 1A ... Outer pipe, 2 ... Power part, 3 ... Cutting blade attaching part, 5 ... Grip, 6 ... Mounting housing main body, 61 ... Housing main body, 61B ... Clamp hole as bolt insertion hole, 62 ... Clamp 64, vibration isolator, 65 ... backup ring, 622 ... fixed piece, 624 ... clamp side positioning hole as positioning hole.

Claims (2)

A brush cutter comprising: an outer pipe provided with a cutting blade mounting portion at one end and a power portion provided at the other end; and a housing connecting the outer pipe and the power portion;
The housing is
A housing body fixed to the power unit;
A clamp member that is formed in a cylindrical shape that is coaxial with the axial direction of the outer pipe, and that is housed in the housing body with the outer pipe inserted.
Configured with
The clamp member is a slit on a straight line formed across both ends in the axial direction;
A pair of fixed pieces provided at positions sandwiching the slit, and
The pair of fixed pieces is an area between both end portions in the axial direction of the clamp member, and by tightening the fixed pieces in directions close to each other, stress due to tightening is applied to both end sides in the axial direction of the clamp member. The brush cutter is provided at a position dispersible toward both directions . The brush cutter according to claim 1,
The brush cutter is characterized in that the entire clamp member is housed in the housing body.

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