JP2006238866A - Bush cutter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bush cutter not only enabling the tilted angle of a reciprocal blade to an operation lever in the front and rear direction to be regulated to the direction facilitating the cutting operation, but also having a miniaturized and weight-reduced gear case and power-transmitting structure in the gear case to reduce the load on an operator, especially having a reduced offset distance from the reciprocal blade to the operation lever in the horizontal direction by reducing the horizontal width of the gear case, also having good balance in the right and left weights, and enabling a rotary blade to be used instead of the reciprocal blade. <P>SOLUTION: The bush cutter is constituted as follows. The gear case 7 of the bush cutter is constituted by assembling the gear case 7 divided to right and left pieces so as to be freely turnable in the upper and lower direction. One of the divided case is attached to the operation lever side so as to be detachable, and the base part of the reciprocal blade is attached to the other divided case. A small-diameter bevel gear 20 which is at the input side, and a large diameter bevel gear 23 the teeth face of which meshing with the bevel gear 20 is directed to side direction are arranged in the gear case, and two cams directing the protruded parts to the opposite directions are attached to the spindle of the large-diameter bevel gear 23. Two arms for driving an upper blade 6A and a lower blade 6B of the reciprocal blade 6 in the front and rear direction according to the rotation of the cams are arranged at the position surrounding the edge part of each cam. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a brush cutter capable of adjusting the front / rear inclination angle of a reciprocating blade, and more particularly, to a brush cutter that suppresses the lateral width of the gear case, reduces the weight of the gear case, reduces the size of the gear case, and improves the left / right weight balance.

  A brush cutter is a working machine that uses an engine or a motor to drive a cutting blade and cuts hedges, plants, weeds, turf, etc. The brush cutter uses reciprocating blades for cutting hedges, plants, grass, etc. There are models equipped with, and models equipped with rotary blades for cutting weeds and the like.

  A brush cutter equipped with a reciprocating blade is equipped with a gear case between the tip of the operation rod and the reciprocating blade in order to drive the reciprocating blade back and forth by converting the rotational power of the engine or motor into a longitudinal motion. The gear case is equipped with a reduction gear, a power conversion mechanism for returning rotational power to reciprocating motion, and the like. A brush cutter that can adjust the reciprocating blade in the front-rear direction so as to facilitate the cutting operation is also known (Japanese Patent Laid-Open No. 8-107719).

JP-A-8-107719

Problems to be solved by the invention

However, in the above-described prior art brush cutter, as shown in FIG. 4 of the same publication, meshing by bevel gears 13 and 12 is performed at a position laterally separated from the meshing position of transmission shaft 6 and worm gear 12. For this reason, the transmission gear case 10 having a wide width is required, and the cam shaft 23 below the bevel gear 22 is also provided in a wide range, so that the cutting blade drive gear case 20 having a wide width is necessary. For this reason, the shape of the entire gear case including the transmission gear case 10 and the cutting blade drive gear case 20 is increased, and in addition to the fact that the two vertical and horizontal shafts 11 and 21 are disposed in the gear case, The overall weight including the load increased, which increased the burden on the operator.
In addition, since the center position of the reciprocating blade is greatly offset in the lateral direction with respect to the operation rod 1, the prior art brush cutter has a poor weight balance between the left and right, and this also increases the burden on the operator. It was.

  The present invention has been proposed to solve these problems, and the inclination angle of the reciprocating blade in the front-rear direction with respect to the operating rod can be adjusted to a direction that facilitates the cutting operation, as well as in the gear case and the gear case. The power transmission structure has been reduced in size and weight to reduce the burden on the operator, and in particular, by reducing the lateral width of the gear case, the lateral offset distance of the reciprocating blade relative to the operating rod has been reduced, providing a good left-right weight balance. Another object of the present invention is to provide a brush cutter that can use a rotary blade instead of a reciprocating blade.

Means for solving the problem

The brush cutter according to claim 1 of the present invention is a power transmission that decelerates the rotational power of the engine or motor in the gear case, further converts it into reciprocating motion, and reciprocates the reciprocating blade mounted on the gear case back and forth. A brush cutter having a structure,
The gear case of the brush cutter is configured such that one of the split cases supported by the operation rod or the handle and the other split case on which the reciprocating blade is mounted are rotatable and at a desired rotation angle. It is assembled and assembled so that it can be locked.
In the gear case, there is disposed a speed reduction mechanism in which a small-diameter bevel gear on the input side and a large-diameter bevel gear with the tooth surface directed to the side are engaged, and on the side of the large-diameter bevel gear. Two circular eccentric cams interlocking with a large-diameter bevel gear and having cam crests facing in opposite directions, an opening in which each eccentric cam is inscribed, and a projecting portion for driving the reciprocating blade back and forth are formed 2 A power conversion mechanism in combination with a single swing arm is provided.

The brush cutter according to claim 1 of the present invention is a brush cutter using an engine as a power source, and the engine is mounted on the hand side of the operating rod. On the other hand, in a brush cutter using a motor as a power source, there are a brush cutter in which the motor is mounted on the hand side of the operating rod, and a brush cutter in which the motor is mounted on a short handle.
The motor is driven by any of a household 100V power source, a secondary battery, and a fuel cell. The secondary battery and the fuel cell may not be attached to the brush cutter side, but may be supported by a mowing worker's waist or the like and connected by an electric signal line. The length of the operation rod is not particularly limited, and an extendable operation rod may be used.

  The reason why the gear case is configured by assembling the left and right divided cases so as to be rotatable is to allow adjustment of the inclination angle of the reciprocating blade in the front-rear rotation direction.

  The reason why the large-diameter bevel gear is arranged in the gear case with the tooth surface facing the side is to suppress the lateral width of the gear case, and two cams are arranged on the side of the large-diameter gear case. Furthermore, the reason why the swing arm is disposed at a position where each cam is inscribed is to suppress the lateral width of the gear case. If it does in this way, a gear case can be reduced in size and weight, and also the power transmission mechanism and power conversion mechanism in a gear case can be reduced in weight.

  If circular eccentric cams are used for the two cams and the cam crests of the eccentric cams are arranged in opposite directions, the swinging arm that is pushed by the peripheral edge of the eccentric cams swings smoothly. Vibration is also greatly reduced. Further, the eccentric cam and the swing arm can be supported with a simple structure.

  As the reciprocating blade, generally, a comb-shaped upper blade and a lower blade are driven in the reverse direction to each other. For this reason, the brush cutter according to claim 1 includes a cam and a swing arm. Two sets of each are provided in the gear case. Note that one eccentric cam and one swing arm may be provided in the gear case so as to correspond to a reciprocating blade in which one of the upper blade and the lower blade is a fixed blade. The gear case is preferably made of aluminum die cast in order to further reduce the weight.

  The brush cutter according to claim 2 of the present invention further has a structure in which a rotary blade can be attached in place of the gear case at the front end side of the operating rod.

  The rotary blade is attached to the distal end portion of the output shaft that protrudes toward the distal end side of the operating rod. The tip of the operating rod is the tip of the operating rod through the body side gear case, elbow with a joint, etc., through which the tip can be turned diagonally downward. On the other hand, the output shaft can be directed downward. With such a brush cutter, it is possible to select a mowing operation using a reciprocating blade and a mowing operation using a rotary blade with a single brush cutter. Purchase of consumers who need both of these mowing operations Significantly reduce the burden. In addition, reciprocating blades and rotating blades can be easily replaced.

The invention's effect

  According to the brush cutter according to claim 1, as a result of reducing the width and the size and weight of the gear case and the internal structure thereof, it becomes possible to provide an easy-to-use brush cutter with reduced front weight. It is now possible to make an easy-to-use brush cutter with a narrow offset distance in the lateral direction of the reciprocating blade with respect to the operating rod, a good left / right weight balance.

  Moreover, as a result of using a circular eccentric cam for the cam arranged in the gear case and arranging the swing arm at a position where this cam is inscribed, the rotational power can be smoothly converted into a reciprocating motion, A brush cutter with good power conversion efficiency, less vibration, and fewer failures can be realized.

  Further, according to the brush cutter according to claim 1, as a result of being able to adjust the inclination angle of the reciprocating blade in the front-rear rotation direction, for example, a cutting surface in a position and direction that is difficult to cut, such as an operation of cutting the upper surface of the hedge. But now I can mow in an easy posture. For this reason, it has become possible to prevent back pain and shoulder pain caused by an unreasonable mowing posture.

  According to the brush cutter according to claim 2, as a result of being able to cope with both reciprocating blades and rotating blades, it is possible to greatly reduce the purchase burden on consumers who require both of the cutting operations. Became.

  FIG. 1 is an overall perspective view showing the brush cutter according to the first embodiment, FIG. 2 is a side view showing an enlarged main part thereof, and FIG. 3A is a side cross-sectional view showing the main part enlarged. FIG. 4B is a view showing a state where the gear case is removed from the main body of the brush cutter, and FIG. 4 is a rear cross-sectional view showing the main part of the brush cutter of the first embodiment further enlarged.

  A brush cutter 1A according to the first embodiment shown in FIG. 1 has a small engine 3 mounted on the proximal end of an operating rod 2 formed of a lightweight metal pipe, and a main body side gear case 4 at the distal end of the operating rod 2. The brush cutter main body 5 to which the reciprocating blade 6 is attached and the gear case 7 that holds the base of the reciprocating blade 6 are detachably mounted so that the comb-shaped reciprocating blade 6 can be driven back and forth by the driving force of the engine 3. It is configured as follows.

  As shown in FIGS. 3 (a) and 3 (b), the front end portion 11a of the power transmission shaft 11 disposed in the operating rod 2 enters the main body side gear case 4, and the front end portion 11a and An upper end portion of the output shaft 12 supported in the main body side gear case 4 in the vertical direction is connected and arranged by meshing with the bevel gears 13 and 14, and the front end portion 12a of the output shaft 12 is disposed on the main body side. Projecting downward from the inside of the gear case 4, a screw groove is formed on the outer peripheral surface of the tip portion 12 a.

As shown in FIGS. 2, 3 (a), and 4, the gear case 7 is configured by assembling a left divided case 8 and a right divided case 9 as viewed from the rear.
The left split case 8 is made of an aluminum die-cast, in which a circular outer peripheral wall 8a, a left side wall 8b, and a cylindrical portion 8c facing upward are integrally formed, and an opening 8d is formed in the center of the left side wall 8b. The bearing 15 is held in a recessed step portion formed around the opening portion 8b on the inner side surface of the left side wall 8b, and the cylindrical portion 8c is held on the inner wall thereof. The input shaft 16 is supported via a bearing 19.

  On the other hand, the right split case 9 has a substantially semicircular arc shape formed in such a size that the outer peripheral wall 8a of the left split case 8 just fits inside, and its front end portion 9d is formed to protrude greatly forward. The outer peripheral wall 9a and the right side wall 9b are integrally formed, and is formed of an integrally formed product made of aluminum die cast in which an opening 9c is formed at the center of the right side wall 9b. The lower end of the front end portion 9d is open. A bearing 17 is held in a recessed step formed around the opening 9c on the inner side surface of the right side wall 9b, and a bottom plate 18 is attached to the opening.

  As shown in FIG. 4, the gear case 7 is configured such that the opposed edges of the left and right split cases 8 and 9 are fitted to support both ends 22 a and 22 b of the support shaft 22 described later on the bearings 15 and 17. Further, nuts N1 and N2 are screwed onto both end portions 22a and 22b of the support shaft 22 from the outside of the divided cases 8 and 9, so that the left and right divided cases 8 and 9 are assembled so as to be freely rotatable up and down. ing.

FIG. 5 is an exploded perspective view showing the main part of the power transmission mechanism and the main part of the power conversion mechanism installed in the gear case.
As shown in FIGS. 4 and 5, the power transmission mechanism in the gear case 7 includes the input shaft 16, a small-diameter bevel gear 20 attached to the distal end portion of the input shaft 16, and a mesh with the bevel gear 20. The large-diameter bevel gear 23 and the support shaft 22 on which the large-diameter bevel gear 23 is mounted are configured such that the large-diameter bevel gear 23 faces the tooth surface 23a to the side, It is disposed at a position close to the inside of the divided case 8.
The power conversion mechanism is for converting the rotational power of the support shaft 22 into a back-and-forth reciprocating motion, and the main part thereof is two eccentric cams mounted on the support shaft 22 with each mountain portion facing in the opposite direction. 30, 31, two swing arms 32, 33, and three guide plates 34, 35, 36.
The eccentric cams 30 and 31 are both made of a strong metal disc, and the two swing arms 32 and 33 are both elliptical openings 32a in which the eccentric cams 30 and 31 are inscribed on the plate surface. 33a, pin support protrusions 32b and 33b, and front and lower protrusions 32c and 33c, which are formed of a strong metal plate. The protrusions 32c and 33c are portions that individually drive the upper blade 6B and the lower blade 6A of the reciprocating blade 6.
Of the three guide plates 34, 35, 36, the two guide plates 34, 36 are formed of a circular metal plate having a slightly larger diameter than the eccentric cams 30, 31, and the other one guide. The plate 35 is formed of a metal plate having an approximately eight shape that is slightly larger than the surface where the eccentric cams 30 and 31 are mounted on the support shaft 22 and overlapped.

One central guide plate 35 is sandwiched between the eccentric cams 30 and 31, one right guide plate 34 overlaps the right surface of the eccentric cam 30, and the left guide plate 36 overlaps the left surface of the eccentric cam 31. As described above, the three guide plates 34, 35, 36 and the two eccentric cams 30, 31 are pivotally supported by the support shaft 22. Then, the two pins 35a and 35b projecting from both sides of the guide plate 35 project from the eccentric cams 30 and 31 toward the guide plates 34 and 36 so as to rotate with the eccentric cams 30 and 31. 30, 31 and guide plates 34, 35, 36 are assembled.
Before the assembly, the swing arms 32 and 33 are arranged at positions where the eccentric cams 30 and 31 are inscribed in the openings 32a and 33a, and the swing arms 32 and 33 are placed inside the split case 9. The pin 26 that is supported on one side is rotatably supported by the pin 26. In this way, the swinging arms 32 and 33 cannot be laterally detached from the two eccentric cams 30 and 31.

As shown in FIGS. 3A and 12, the reciprocating blade 6 is constructed by assembling a comb-shaped upper blade 6B and a lower blade 6A, and the rear end portions of the upper blade 6B and the lower blade 6A are, for example, The upper blade 6B is distributed rearward with an interval in a direction in which the base portion of the upper blade 6B is on the left side and the base portion of the lower blade 6A is on the right side. The upper blade 6B and the lower blade 6A are bolted together with the guide members 43, 42, 44 mounted on the divided case 9 toward the front, and are formed on the upper blade 6B and the lower blade 6A. The bolt hole is a long hole directed in the front-rear direction. For this reason, the movement in the front-back direction of the upper blade 6B and the lower blade 6A is possible.
The tip portions of the projecting portions 32c, 33c facing the front lower side of the two swing arms 32, 33, and the rear end portions of the upper blade 6B and the lower blade 6A of the reciprocating blade 6 are an upper blade 6B and a lower blade 6A. It is connected to mounting members 38 and 40 mounted on the upper surface of the rear end portion via connecting members 37 and 39.

Next, the procedure and mounting structure for mounting the gear case 7 to the brush cutter body 5 will be described with reference to FIGS.
As described above, when the gear case 7 to which the reciprocating blade 6 is attached is attached to the front end portion of the brush cutter body 5, first, the inner diameter of the protruding end portion 16 b of the input shaft 16 is connected to the front end portion 12 a of the output shaft 12. A mounting member 28 having an outer peripheral wall formed in conformity with the outer peripheral wall and having a thread groove 28 a formed on the outer peripheral surface thereof is fitted into the output shaft 18.
Then, the nut N4 is screwed to the distal end portion 12a of the output shaft 12, the mounting member 28 is mounted to the distal end portion 12a of the output shaft 12, and then the upper end portion of the input shaft 16 is screwed to the mounting member 28. Thus, the output shaft 12 and the input shaft 16 are connected. In this way, the driving force of the engine can be transmitted into the gear case 7.

  Subsequently, as shown in FIG. 3A, the upper end portion of the support arm 51 that is protruded and fixed rearward and upward from the outer peripheral wall 8a of the divided case 8 that supports the input shaft 16, and the operation rod 2 The lower surface of the mounting member 50 that is mounted in the vicinity of the tip of the head is mounted with bolts 52, 53 and nuts, and the divided case 8 is mounted on the operating rod 2. In addition, bolt holes 50a, 50b, 51a formed in the mounting member 50 and the support arm 51 are formed as long holes so that the mounting position of the mounting member 50 toward the operating rod 2 can be adjusted.

  3A and 4, the high-speed rotational power by the input shaft 16 is decelerated by the meshing of the bevel gears 20 and 23 to rotate the support shaft 22 at a reduced speed. As a result of the rotation of the eccentric cams 30 and 31, the oscillating arms 32 and 33 are converted into oscillating motions with the pin 26 as a fulcrum, and the upper blade 6B and the lower blade 6A are alternately driven back and forth.

FIG. 7 is a diagram illustrating a usage example of the brush cutter according to the first embodiment.
As shown in FIG. 1, in the brush cutter 1 of this embodiment, the reciprocating blade 6 has an inclination angle that is directed horizontally in a state in which the front end portion of the operation rod 2 is directed forward and downward. The inclination angle is suitable for cutting the side of the hedge, the lawn, etc. For example, the inclination angle is unsuitable when the upper surface of the hedge is cut. For this reason, in the brush cutter 1 of Example 1, as shown in FIG. 7, the inclination angle of the reciprocating blade 6 in the front-rear rotation direction can be adjusted.

As shown in FIG. 2, this rotation locking is performed by using a guide plate 55 mounted from the upper surface to the rear surface of the split case 9 on which the reciprocating blade 6 is mounted, and the support swing arm 51. , By attaching with bolts 56 and 57.
The bolt hole 55a through which the bolts 56 and 57 formed in the guide plate 55 are inserted is an arc centered on the support shaft 22 so that the inclination angle in the front-rear direction of the reciprocating blade 6 and the split case 9 can be changed. It is formed in the shape of a long hole.

FIG. 8 is a side view of an essential part showing a state where a rotary blade is attached to the brush cutter body.
As shown in FIG. 8, the brush cutter 1 </ b> A according to the first embodiment can also mount the rotary blade 60 on the distal end portion 12 a of the output shaft 12 protruding from the distal end portion of the brush cutter main body 5. When the rotary blade 60 is mounted, the rotary blade 60 is inserted into the distal end portion 12a of the output shaft 12, and then the mounting member 28 having a thread groove 28a formed on the outer peripheral surface thereof is inserted into the output shaft 12. What is necessary is just to screw and fasten the nut N4 to the 12 front-end | tip parts 12a.

Next, a brush cutter according to a second embodiment of the present invention will be described.
FIG. 9 is a perspective view showing an essential part of the brush cutter according to the second embodiment, FIG. 10 is an exploded perspective view of the gear case, FIG. 11 is also a side sectional view, and 12 is a rear sectional view. In these drawings, the same reference numerals are given to the portions common to FIGS.

  The brush cutter 1B of the second embodiment uses an engine or a motor mounted on the proximal end of the operating rod 2 as a power source, like the brush cutter of the first embodiment. As shown in FIG. 9, a gear case 4 is attached to the distal end portion of the operation rod 2.

As shown in FIG. 10, FIG. 11 and FIG. 12, the gear case 4 has a wall surface 70a having an arcuate upper portion and a lower portion facing downward, and wall surfaces are formed on one of these one side and the lower portion of the other one side. A gear case in which 70b, 70c are formed, a circular edge portion 70d is formed on the upper portion of the other side, an opening portion 70e is formed in a portion surrounded by the edge portion 70d, and a flat collar portion 70f is formed at the lower end portion. A main body 70;
A lid body in which a side wall 71a for closing the opening 70e and a holder part 71b for mounting the tip of the operating rod 2 are integrally formed, and a circular edge 71c surrounding the edge 70d is formed on one side of the side wall 71a. 71,
A bottom plate 72 covering the lower portion of the flange portion 70f is assembled.

  Then, similarly to the gear case used in the brush cutter according to the first embodiment, the opening portions 70g and 71f are provided at the upper central portion of the wall surface 70b of the gear case main body 70 and the wall surface portion of the lid 71 facing this portion. The bearings 17 and 15 are formed on the inner side along the opening portions 70g and 71f, and the bearings 22 and 15 support the shaft 22 on which the large-diameter bevel gear 23 and the cams 30 and 31 are mounted. Is supported. Then, nuts N1 and N2 are screwed to both end portions 22a and 22b of the support shaft 22, and the gear case main body 70 and the lid body 71 are rotatably assembled with the support shaft 22 as a fulcrum.

The upper portion of the holder portion 71b is formed of a cylindrical portion, and a flange portion 71g is formed at the upper end thereof. A cylindrical connection member 75 for connecting the tip end of the operating rod 2 to the holder portion 71b is inserted into the protruding end portion of the holder portion 71b, and a flange portion 75a formed on an intermediate surface of the connection member 75. The flange portion 71g is mounted using a bolt 78 and a nut 79.
An input shaft 76 is supported in the connecting member 75 via bearings 19a and 19b, and a small-diameter bevel gear that meshes with the large-diameter bevel gear 23 is attached to the lower end portion of the input shaft 76. Has been. The rear end portion of the input shaft 76 is formed of a cylindrical portion in which a thread groove is formed on the inner peripheral wall. The front end of the connecting member 11 is attached to the rear end of the connection member 75 in a state where the front end of the operating rod 2 protrudes, and the rear end of the input shaft 76 is disposed in the operating rod 2. Is screwed in.

  As shown in FIGS. 11 and 12, the large-diameter bevel gear 23, the two cams 30, 31 and the guide plates 34, 35, 36 are the same as those of the brush cutter of the first embodiment. The bevel gear 23 having a diameter is disposed inside the lid 71, and the two cams 30 and 31 and the guide plates 34, 35, and 36 are disposed inside the gear case body 70.

  The swing arms 32 and 33 arranged in the brush cutter 1B of the second embodiment are provided at the same position as the swing arm used in the brush cutter of the first embodiment and perform the same movement. As shown in FIG. 11, the swinging arms 32 and 33 used in the brush cutter 1A of No. 2 have protrusions 32c and 33c that drive the upper blade 6B and the lower blade 6A back and forth, and protrude downward. Intermediate surfaces of the moving arms 32 and 33 are rotatably supported by the pin 26.

  The base portion of the reciprocating blade 6 is supported by a gear case body 70, and the reciprocating blade 6 is rotatable together with the gear case 70 with respect to the lid 71 supported by the operation rod 2. The rotation is fixed manually, and the rotation is fixed. The mounting member 55 formed with the arc-shaped elongated hole 55a mounted on the gear case body 70, and the mounting surface (not shown) provided on the operation rod 2. Is carried out using bolts 59.

It is the whole perspective view which showed the brush cutter of Example 1. FIG. It is the side view which expanded and showed the principal part similarly. (A) is side surface sectional drawing which expanded and showed the principal part similarly, (b) is the figure which showed the state which removed the gear case from the brush cutter main body. It is the rear surface sectional view which expanded and showed the principal part of the brush cutter of Example 1. FIG. It is a disassembled perspective view which shows the principal part of the power transmission mechanism with which the gear case is equipped. (A) And (b) is a figure which showed the motion of the rocking | fluctuation arm accompanying rotation of a cam. It is the figure which showed the usage example of the brush cutter of Example 1. FIG. It is the principal part side view which showed the state which attached the rotary blade to the brush cutter main body. It is the perspective view which showed the principal part of the brush cutter of Example 2. FIG. It is the perspective view which decomposed | disassembled and showed the gear case similarly. Similarly, it is a side sectional view. It is a rear surface sectional view similarly.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1A Brush cutter of Example 1 1B Brush cutter of Example 2 Control rod 3 Engine 4 Body side gear case 5 Brush cutter body 6 Reciprocating blade 6A Lower blade 6B Upper blade 7 Gear case 8 Split case 9 Split case 11 Power transmission shaft 12 Output Shaft 13 Bevel gear 14 Bevel gear 16 Input shaft 20 Small-diameter bevel gear 22 Support shaft 23 Large-diameter bevel gear 30 Cam 31 Cam 32 Oscillating arm 32a Opening 33 Oscillating arm 33a Opening 34 Guide plate 35 Guide plate 36 Guide plate

Claims (2)

A brush cutter having a power transmission structure that decelerates rotational power from an engine or motor in a gear case, further converts it into reciprocating motion, and reciprocates a reciprocating blade mounted on the gear case back and forth,
The gear case of the brush cutter is configured such that one of the split cases supported by the operation rod or the handle and the other split case on which the reciprocating blade is mounted are rotatable and at a desired rotation angle. It is assembled and assembled so that it can be locked.
In the gear case, there is disposed a speed reduction mechanism in which a small-diameter bevel gear on the input side and a large-diameter bevel gear with the tooth surface directed to the side are engaged, and on the side of the large-diameter bevel gear. Two circular eccentric cams interlocking with a large-diameter bevel gear and having cam crests facing in opposite directions, an opening in which each eccentric cam is inscribed, and a projecting portion for driving the reciprocating blade back and forth are formed 2 A brush cutter having a power conversion mechanism combined with a single swing arm. The brush cutter according to claim 1, having a structure in which a rotary blade can be attached in place of the gear case on the front end side of the operating rod.

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