JP2008142072A - Shoulder-hanging type bush cutter for hillside - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bush cutter capable of easily adjusted the angle of a rotary knife even in rotating when the cutter is hung on the shoulder. <P>SOLUTION: The bush cutter is a shoulder-hanging type bush cutter transmitting rotation from a rotation driving source 2 to a rotary knife 1 through a transmission shaft and cutting vegetated grass with the rotary knife 1, wherein a coil spring is connected on the middle of the transmitting shaft, the coil spring can transmit the rotation through a swingable element 12 and a wire 9 connected with an operation lever 8 is hung on at least one off-position of the swinging center of the swingable element 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a shoulder-type brush cutter for cutting weeds and the like grown on the ground surface with a rotary blade while being carried on a shoulder.

  Shoulder-type brush cutters are widely used to harvest weeds, etc. grown in paddy fields, fields, and forests. For example, as shown in FIG. 7, the shoulder brush cutter includes a small engine 2 and a rotary blade 1, and the rotary motion is transferred to the rotary blade 1 through a transmission shaft inserted from the engine 2 into the outer tube 16. Tell. An operator hangs a shoulder belt 30 provided on the outer tube 16 and grips the grip 5 of the U-shaped handle 11 that is also attached to the outer tube 16 to perform the cutting operation.

  The brush cutter is used by adjusting the length of the shoulder belt in advance and keeping the ground and the rotary blade parallel. While keeping the rotary blade of the brush cutter parallel to the ground as much as possible, the handle is trimmed by operating the handle so that the rotary blade is left and right. If the rotary blade is tilted with respect to the ground, the cutting size of the grass will be different, and the plant height will not be cut evenly, or the cutting will be striped and unsightly at a distance, making effective cutting impossible. There is also a risk that the rotating blade hits the ground. When the ground is flat, there are few problems, but when the ground reaches the slope, for example, the slope of the bank, in order to keep the rotary blade and the slope of the bank parallel, you can lift the brush cutter, It is necessary to change the working position. In extreme cases, the length of the shoulder belt must be adjusted.

  Since the brush cutter is equipped with an engine, it is heavy, and cutting in an unreasonable posture is dangerous. For adjusting the length of the shoulder belt, the rotation of the rotary blade must be stopped once, which is troublesome.

  In Patent Document 1, a flexible shaft is inserted as a transmission shaft into a flexible tube that is inserted into and protrudes from an outer tube, and connects the output shaft of the engine to the rotary blade. There is shown a portable power brush cutter on which a rotary blade support rod for supporting is hung. This brush cutter makes it possible to adjust the angle of the front and rear of the rotary blade by operating the rotary blade support rod along the outer tube.

  However, the rotary blade of this brush cutter is supported only by the rotary blade support rod, and if the angle of the rotary blade is adjusted during rotation, the rotary blade swings and is unstable. Therefore, it is difficult to maintain parallelism between the rotary blade and the ground. Further, a rotation lever for adjusting the angle of the rotary blade is provided on the outer tube. In order to operate the pivot lever during mowing, you must hold the handle with one hand. For this reason, the center of gravity becomes unstable, which is dangerous.

  Patent Document 2 discloses a portable power brush cutter that includes a rotary blade support member and a rotary blade at the distal end of an outer tube, and a flexible shaft that connects the output shaft of the engine to the rotary blade as a transmission shaft. ing. In the joint portion between the distal end portion of the outer tube and the rotary blade support member, the rotary blade can be rotated around the horizontal axis orthogonal to the transmission axis, and the angle of the rotary blade is adjusted.

  However, this brush cutter is troublesome because the rotation of the rotary blade must be stopped when the angle is adjusted. Moreover, since the angle adjustment is performed by hitting the tip of the rotary blade with the ground, the rotary blade may be damaged. Further, the flexible shaft is inserted through a holding tube formed of resin. Therefore, during rotation of the flexible shaft, friction due to contact is likely to occur between the flexible shaft and the holding tube, and heat is generated, which is dangerous.

Japanese Utility Model Publication No. 3-17619 JP 2006-34255 A

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a brush cutter that can easily adjust the angle of the rotary blade even while the rotary blade is rotating.

  The brush cutter according to claim 1, which has been made to achieve the above object, transmits a rotational motion from a rotary drive source to a rotary blade via a transmission shaft, and is vegetated by the rotary blade. In a shoulder-type brush cutter that cuts off the grass, a coil spring is connected to the middle of the transmission shaft, and the coil spring penetrates the swinging member and can conduct the rotational motion. A wire connected to the hand operating means is suspended from at least one fulcrum off the center of movement. The rotational drive source is, for example, an engine.

  Similarly, the brush cutter according to claim 2 of the present invention is the brush cutter according to claim 1, wherein the hand operating means is a shift lever attached to the operation handle. .

  A brush cutter according to a third aspect is the brush cutter according to the first aspect, characterized in that the hand operating means is a grip lever attached to an operation handle.

  A brush cutter according to a fourth aspect is the brush cutter according to the first aspect, wherein the fulcrum is a fulcrum at two point symmetric points deviating from the swing center of the swing member, The fulcrum is suspended by a wire through the hand operating means.

  A brush cutter according to a fifth aspect is the brush cutter according to the first aspect, wherein an antigravity load direction is provided between the swinging member and a swinging member cover supporting the swinging center of the swinging member. A biasing spring is stretched over.

  The brush cutter of the present invention can be freely adjusted by the hand operating means even when the rotary blade is rotated during use on the shoulder. Therefore, the ground and the rotary blade can be kept parallel to the uphill slope and the downhill slope by the hand operating means as well as the flat ground in the direction of the cutting operation. Therefore, even on slopes, the plant height can be cut evenly. There is no uncut grass, and effective cutting work can be performed even on rough terrain or uneven ground, improving work efficiency. Further, by changing the angle of the rotary blade, it is possible to easily mow grass evenly on topography that could not be mowed until now.

  Adjusting the angle of the rotary blade is a simple operation just by operating the manual operation means provided on the handle, and since the parallelism between the rotating teeth and the ground can be adjusted immediately to the terrain, the entire heavy brush cutter There is no need to lift, move the work position or work position, or adjust the length of the shoulder belt. For this reason, time spent for various operations is eliminated, fatigue is reduced, and mowing can be performed safely and efficiently, and work efficiency can be improved.

  Further, during use of the brush cutter, the coil spring absorbs the vibration and impact of the rotary blade. Therefore, the brush cutter does not transmit the vibration of the rotary blade to the handle by this buffering action. Therefore, it is possible to prevent white wax disease or the like that is said to develop in the fingers due to vibration.

Preferred form for carrying out the invention

  Hereinafter, preferred embodiments for carrying out the present invention will be described in detail, but the scope of the present invention is not limited to these embodiments.

  The structure of a brush cutter according to an embodiment to which the present invention is applied is shown in FIGS.

  An overall perspective view of this brush cutter is shown in FIG. The brush cutter is mainly configured such that the engine 2 is connected to the rotary blade 1 via the engine side outer tube 3, the joint portion 12, the rotary blade side outer tube 4 and the rotary blade support portion 10. A U-shaped handle 11 is attached to the engine side outer tube 3. Grips 5 are provided at both ends of the handle 11. One grip 5 is provided with a throttle lever 6 and is connected to the engine 2 through a throttle wire 7. The other grip 5 is provided with a shift lever 8 and is connected to the joint portion 12 via a wire 9.

  A shoulder belt 30 is attached between the U-shaped handle 11 of the engine-side outer tube 3 and the engine 2 and at the overall weight balance position. The rotary blade side outer tube 4 and the rotary blade 1 form a fixed angle and are supported by the rotary blade support portion 10. Further, a scattering prevention cover 23 is provided in the vicinity of the tip of the engine side outer tube 3.

  FIG. 2 shows the vicinity of the joint portion of the brush cutter of FIG. In the joint portion 12, the swing member 14 is covered inside the swing member cover 15. The swing member cover 15 and the engine side outer tube 3 are integrated. Further, the swing member 14 and the rotary blade side exterior tube 4 are integrated. Holes are formed at the ends of the swing member cover 15 and the swing member 14. The engine side transmission shaft 19 and the rotary blade side transmission shaft 22 are joined by a coil spring 17 and fixed by a joint 21. The joined transmission shafts 19 and 22 and the coil spring 17 are connected to the rotary blade 1 from the output shaft (not shown) of the engine 2 through the swing member 14, the swing member cover 15, and the exterior tubes 3 and 4. ing. Further, a bearing 18 is provided inside the engine side outer tube 3 and the rotary blade side outer tube 4 to support the inserted transmission shafts 19 and 22.

  Further, wire stoppers 27a and 27b are embedded in the swing member 14, and are connected to the shift lever 8 via two wires 9a and 9b.

  This brush cutter is used as follows. As shown in FIG. 1, a shoulder belt 30 provided on the engine-side outer tube 3 is hung, and the parallelism between the rotary blade 1 and the ground is adjusted by changing the length of the belt. The throttle lever 6 is rotated and the engine 2 is rotated via the throttle wire 7. The rotational motion of the engine 2 is transmitted to the engine side transmission shaft 19, the coil spring 17 and the rotary blade side transmission shaft 22 which are connected. Further, the rotary motion of the rotary blade side transmission shaft 22 rotates the rotary blade 1 via the rotary blade support 10.

  When the ground is flat, the grip 5 is gripped with both hands, and the rotary blade 1 is swung left and right while keeping the distance and parallelism between the rotary blade 1 and the ground, and the grass is cut.

  When the ground approaches an uphill slope, as shown in FIG. 2, when the shift lever 8 is turned, the wires 9 a and 9 b are pulled, and the swing member 14 swings clockwise about the swing shaft 20 ( (See the two-dot broken line). Along with this, the rotating coil spring 17 is bent. Therefore, the rotary blade 1 can rotate while keeping its rotation and keep parallel with the climbing slope.

  When the ground approaches the down slope, the wires 9a and 9b are pulled by turning the shift lever 8 in the opposite direction, and the swing member 14 swings counterclockwise. Turn to.

  During use of the brush cutter, the coil spring 17 absorbs the vibration and impact of the rotary blade. Therefore, the brush cutter does not easily transmit the vibration of the rotary blade to the handle 11 due to this buffering action. Moreover, even when the rotary blade hits a stone or the like, the impact is reduced.

  The structure of a brush cutter according to another embodiment to which the present invention is applied is shown in FIG. Except for a single wire, it has the same structure as the above brush cutter.

  When the ground approaches an uphill slope, when the shift lever 8 is turned, the wire 9 is pulled, and the swing member 14 swings clockwise about the swing shaft 20 (see the two-dot broken line). Along with this, the rotating coil spring 17 is bent. Therefore, the rotary blade 1 can rotate while keeping its rotation and keep parallel with the climbing slope.

  When the ground approaches the down slope, the wire 9 is pushed out by turning the shift lever 8 in the opposite direction, and is lowered by the weight of the rotary blade 1, the rotary blade support portion 10 and the rotary blade side outer tube 4, Since the swing member 14 swings counterclockwise, the rotary blade 1 faces downward.

  FIG. 4 shows a perspective view of another embodiment of the rotary operation means of the brush cutter to which the present invention is applied. 1 has the same structure as the brush cutter of FIG. 1 except that the rotation operating means is a grip lever 25 incorporated in the grip. Thereby, by rotating the grip lever 25 to the right and left, the swinging portion can be moved up and down to adjust the angle.

  FIG. 5 is a perspective view of the vicinity of the rotary blade of a brush cutter according to another embodiment to which the present invention is applied. 1 has a structure similar to that of the brush cutter of FIG. 1 except that the scattering prevention cover 23 is provided in the immediate vicinity of the rotary blade 1 on the rotary blade side outer tube 4. Thereby, the pebbles and the like scattered in the direction of the operator by the rotational movement of the rotary blade 1 can be reliably prevented by the scattering prevention cover 23.

  FIG. 6 is an exploded perspective view showing the structure of the joint portion of another embodiment of the brush cutter to which the present invention is applied. Both ends of the oscillating member 14 are engaged with the inner side of the oscillating member cover 15 by a torsion spring 26, respectively. The torsion spring 26 is urged in the direction opposite to the load direction by the rotary blade 1, that is, in the counterclockwise direction indicated by the arrow in the drawing. The remaining structure is the same as that of the brush cutter in FIG.

  Since the oscillating member 14 is forced upward by the torsion spring 26, it antagonizes the couple due to the weight of the oscillating member 14 and the rotary blade 1, and the rotary blade is merely applied to the hand operating means. 1 can be moved up and down. Further, since no force is required at this time, the swinging member 14 may be damaged by hitting the upper portion of the cover 15 by momentum, or the rotary blade that has been subjected to inertial movement may be lifted momentarily. Absent.

  The structure of the above-described embodiment of the present invention can be applied to a loop handle type mower, a two-grip type mower, a backpack type mower, and the like.

It is a perspective view of a shoulder type brush cutter to which the present invention is applied. It is principal part sectional drawing of the shoulder type brush cutter to which this invention is applied. It is principal part sectional drawing of another shoulder-type brush cutter to which this invention is applied. It is a perspective view of the manual operation means of another shoulder type brush cutter to which the present invention is applied. It is a principal part perspective view of another shoulder-type brush cutter to which this invention is applied. It is a principal part disassembled perspective view of another shoulder-type brush cutter to which this invention is applied. It is a perspective view of the conventional shoulder type brush cutter.

Explanation of symbols

  1 is a rotary blade, 2 is an engine, 3 is an engine side outer tube, 4 is a rotary blade side outer tube, 5 is a grip, 6 is a throttle lever, 7 is a throttle wire, 8 is a shift lever, and 9, 9a, and 9b are wires 10 is a rotary blade support part, 11 is a handle, 12 is a joint part, 14 is a rocking member, 15 is a rocking member cover, 16 is an outer tube, 17 is a coil spring, 18 is a bearing, 19 is an engine side transmission shaft, 20 is a rocking shaft, 21 is a joint, 22 is a rotary blade side transmission shaft, 23 is a scattering prevention cover, 25 is a grip lever, 26 is a torsion spring, 27a and 27b are wire stoppers, 28a and 28b are wire stoppers, 30 is It is a shoulder belt.

Claims (5)

  In a shoulder type brush cutter that transmits rotational motion from a rotary drive source to a rotary blade via a transmission shaft, and cuts off the grass planted by the rotary blade, a coil spring is connected in the middle of the transmission shaft. The rotational movement can be conducted through the swinging member, and a wire connected to the hand operating means is suspended from at least one fulcrum off the swinging center of the swinging member. Characteristic brush cutter.   2. The brush cutter according to claim 1, wherein the hand operating means is a shift lever attached to an operation handle.   The brush cutter according to claim 1, wherein the hand operating means is a grip lever attached to an operation handle.   The fulcrum is a fulcrum at two point-symmetrical points deviating from the oscillating center of the oscillating member, and the two fulcrum points are suspended by a wire through the hand operating means. The brush cutter according to claim 1.   The spring for urging in the antigravity load direction is stretched between the swing member and a swing member cover that supports the swing center of the swing member. Brush cutter.

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