JP5633082B1 - Brush cutter - Google Patents

Abstract

An operation of a brush cutter is performed by bringing a tip of a rotary blade close to the ground, but it is difficult to hold the tip at a certain height from the ground. In addition, there are problems such that the cutting edge sinks into the ground and scatters of pebbles and the like. An object of the present invention is to improve workability by bringing the cutting edge of a rotary blade into a floating state and to reduce the occurrence of scattering of pebbles and the like. A brush cutter having a tip type rotary blade stabilizes workability by two-point grounding with a continuous circular bent portion formed on the rotary blade and a grounding tool below the cutting blade, and against the ground. Thus, the brush cutter has solved the problem by forming a space S1 in which the lower surface of the chip opens outwardly above the outer periphery. [Selection] Figure 4

Description

The present invention relates to a brush cutter for cutting out weeds such as parks, schoolyards, playgrounds, and roads, and can be suitably used particularly when the ground is relatively flat and hard.

In general, a brush cutter is provided with a cutting portion made of a rotary blade or the like on the front end side of a main pipe and a drive source made of a small engine or the like on the rear end side, and an operator hangs an operation portion in the middle. Hold and hold, move forward while moving the cutting part to the left and right, and perform weeding work such as weeds.

The rotary blade used in the cutting part on the front end side of the brush cutter is generally provided with a large number of chip mounting teeth protruding from the outer periphery of the disk-shaped substrate, as described in Patent Document 1 below. The lower surface is attached in parallel to the mounting surface of the rotary blade.

When cutting, the tip of the rotary blade comes into contact with the ground downwards, lowering the weed cutting height, bringing the rotary blade into contact with the ground in order to uproot the weed, and cutting the blade tip into the ground. Work.

  Further, as described in the following Patent Document 2, a required number of cutting blades are directly cut on the peripheral edge of the body plate without using a chip, and the cutting blade is inclined or curved upward with respect to the body plate. There are some that perform cutting work by moving the cutting blade parallel to the ground while grounding the body plate to the ground.

Patent Document 3 discloses an integrated unit in which a required number of cutting blades are cut directly on the outer peripheral edge portion of the rotary cutter plate body without using a chip, and the outer peripheral edge portion of the plate body is bent upward to form an inclined outer peripheral edge portion. Although there was a plate-type mowing blade with an aperture, the rotary blade against the ground was always in contact with the entire circumference.

JP-A-11-146720 JP-A-6-284809 Japanese Utility Model No. 63-14053 (Japanese Utility Model Laid-Open No. 1-118619)

Brush cutters are used to process weeds in parks, schoolyards, playgrounds, roads, etc., but these places are relatively flat and hard ground. During the mowing operation, in order to delay the regeneration of weeds as much as possible, there are many operations in which the cutting edge of the rotary blade is brought into contact with the ground or the cutting edge is submerged in the ground.

The brush cutter weighs about 4Kg and has a total length of 1.8m, and the rotating blade is grounded while balancing the ends of the mowing part and engine part with a band attached from the shoulder at the approximate center and the handle attached to the main pipe. The mowing operation is carried out while being held at an angle of about 30 degrees. At this time, it is difficult to swing and advance while holding the cutting edge of the rotary blade at a certain height with respect to the ground. Moreover, since the cutting edge of the rotary blade bites into the ground more and more, it is difficult to hold the cutting edge of the rotary blade at a constant height.

The rotary blade rotates at a high speed of 6,000 rpm, and pebbles hitting the side surface of the chip and the chip mounting tooth are scattered at a high speed, which may pose a danger to the worker and the surrounding area.

In addition, there are many problems such as the back of the chip planting part being worn out by sand or the like deposited on the chip planting part and chipping off.

In addition, there is a type in which a necessary number of cutting blades are directly cut on the peripheral edge of the body plate without using a chip, and the cutting blade is brushed while the cutting blade is moved parallel to the ground while a part of the body plate is grounded to the ground. However, it is difficult to keep the distance between the ground and the cutting blade, and it is not suitable for mowing work such as soft grass or hard grass, and the root of the weed is cut while cutting the soil with the cutting blade positioned a few centimeters below the ground. It was a thing.

Furthermore, a plate shape of an integrated diaphragm in which a required number of cutting blades are cut directly on the outer peripheral edge portion of the rotary cutter plate body without using a tip, and the outer peripheral edge portion of the plate body is bent upward to form an inclined outer peripheral edge portion. Although there was a grass cutting blade, the rotary blade is always in contact with the ground all around, and the outer peripheral edge of the plate is bent upward to form the inclined outer peripheral edge. It did not have a floating effect, and lacked light work.

On the other hand, in the invention of claim 1 of the present invention, (a) a circularly continuous bent portion is formed in the vicinity of the outer periphery of the rotary blade in which a large number of chips are implanted on a disk-shaped substrate. (B) The lower surface of the chip is raised above the rotary blade mounting portion so as to form an outwardly extending gap S1 between the ground and the lower surface of the chip. (C) A brush cutter in which the lower surface of the tip is positioned outward from the upper surface of the tip at the tip end of the outer periphery of the rotary blade.

Further, the bent portion formed on the rotary blade is a brush cutter having a rotary blade positioned on the outermost side where a continuous circle can be formed on the disc-shaped substrate.

Further, (a) a bent portion that is continuous in a circle is formed in the vicinity of the outer periphery of the rotary blade in which a large number of chips are implanted on a disk-shaped substrate, and a grounding tool provided below the bent portion and the rotary blade (B) The lower surface of the tip is inclined upward with respect to the rotary blade mounting portion so as to form an outwardly extending gap S1 between the ground and the lower surface of the tip outside the bent portion. (C) Furthermore, a gap S2 is formed between the ground and the back surface of the disc-shaped substrate in the immediate vicinity of the bent portion.

In the present invention, the weight is about 4 kg, the total length is 1.8 m, and the brushing work is performed while balancing the both ends of the cutting portion and the engine portion by the band attached from the shoulder at the approximate center and the handle attached to the main pipe. However, at this time, the cutting edge of the rotary blade is fixed with respect to the ground by grounding at two points: a circularly bent portion provided near the outer periphery of the rotary blade and a grounding tool provided below the rotary blade. Stable mowing work can be done by sliding the ground while maintaining the height of. Therefore, since the operator can concentrate on moving forward while swinging the handle left and right, the worker can work lightly with less fatigue.

Since the work can be performed so that the lower surface of the chip naturally slides according to the shape of the ground while maintaining the gap S1 between the chip and the ground, a beautiful finish can be obtained without the chips getting into the ground. In addition, since the grounding portion is in contact with one point on the grounding tool and one point on the continuous circle of the bent portion, the grounding resistance is extremely small.

When the ground part is grounded at two points, that is, the bent portion of the rotary blade and the grounding tool provided below the rotary blade, an outwardly extending gap S1 is formed between the ground surface and the lower surface of the chip. The blade edge always keeps the upward inclination while floating from the ground, but by rotating the rotary blade and swinging the cutting part to the left by the operator, a reaction force along the bottom surface of the chip is generated, and weed is drawn in. Cut at a right angle corner on the bottom of the chip. Further, since the gap S1 has a wedge shape, a component force along the lower surface of the chip enters and pushes it up and down. This becomes a force to lift the rotary blade, and it can float and mowing the work smoothly.

Further, due to the rotation of the rotary blade and the left / right swing of the cutting part by the operator, a force along the front surface of the chip is generated upward, and an upward component force acts on the cutting action line. As a result, the mowing unit tries to float upward and presses pebbles or the like against the ground to prevent scattering. Furthermore, when the lower surface of the tip comes into contact with pebbles, etc., the rotary blades lift and escape due to the rotational force of the rotary blade and the upward tilt of the lower surface of the tip, and the pebbles etc. are pressed downward, so that they can be prevented from scattering to the side. it can. Also, when the bent part in the swing direction is in contact with the ground, the cutting action point of the tip bottom corner at the tip of the outer periphery is the minimum gap, and after cutting, the bottom surface of the tip is gradually widened. The pebbles etc. are completely pressed down and the contact with the chip is reduced.

Further, the outwardly extending gap S1 provided between the ground surface and the lower surface of the chip allows sand, mowing grass, etc., which are about to stay in front of the cutting blade to pass over the branching portion and be discharged to the inside of the rotary blade. This stagnates in front of the tip and rotates, prevents disc teeth from being worn on the back surface of the tip mounting teeth, reduces tip dropping, and increases the durability of the rotary blade.

Furthermore, since the tip bottom surface of the tip of the tip on the outer periphery of the rotary blade is positioned outward from the top surface of the tip, the tip top of the tip is conventionally at the grass cutting position. By pushing down, the soft grass was not cut and left uncut. As countermeasures for these problems, conventionally, since the cutting blade is submerged in the ground to perform the brushing work, the abrasion of the rotary blade due to the soil has been often observed. However, the present invention also eliminates these problems.

In the present invention, the tip lower surface is inclined upward with respect to the rotary blade mounting portion, and the tip lower surface is positioned outward from the chip upper surface at the tip end portion of the outer periphery of the rotary blade, so that the tip position from the ground is increased. However, since the cutting position of the tip of the chip is the bottom surface of the tip, the cutting height does not change even when compared with the conventional tip type.

According to the second aspect of the present invention, the disc-like substrate is provided with a notch for forming chip mounting teeth for chip implantation. Since the bent part is formed on the outermost side that can be made into a continuous circle avoiding this notch part, the tip and the grounding point by the bent part can be brought close to each other, and the vertical movement of the chip during cutting operation Since there is very little, and the ground of weeds can be cut off, the regeneration of weeds was delayed. Further, since the circular bent portion that is continuous at the position closest to the outer periphery of the rotary blade and in the immediate vicinity of the root portion of the tip mounting tooth is formed, the strength of the rotary blade can be increased.

According to the invention of claim 3, a circularly continuous bent portion is formed near the outer periphery of the rotary blade in which the chip is implanted on the chip mounting tooth of the disc-like substrate, and the bent portion and the rotary blade are below the rotary blade. When two points with the grounding device provided are grounded, the lower surface of the tip is inclined upward with respect to the rotary blade mounting portion so as to form an outwardly expanding gap S1 between the ground and the lower surface of the tip. A gap S2 is formed immediately inside the portion. Since the tip of the rotary blade has a certain thickness, it is easy to accumulate grass, sand, etc. on the front surface in the rotational direction during the mowing operation as described above. Since the gap S2 is formed immediately inward of the bent portion, accumulated sand and the like can be immediately escaped over the branch portion toward the cutting blade presser, and an abnormality that occurs on the back surface near the inside of the tip mounting tooth space This has the effect of preventing wear and preventing chipping off. In addition, since the gap S2 is formed in the inner part of the bent portion, the space from the bent portion to the cutting blade presser can be made a space, and the grounding portion is on a circle where one point of the grounding tool and the bent portion are continuous. Since the contact with one point is very small, the grounding resistance is extremely low, and the mowing work can be done lightly.

FIG. 1 is a schematic perspective view showing a usage state of the brush cutter of the present invention. 2 is a side view of the rotary blade of FIG. FIG. 3 is a plan view and a sectional view showing a part of the rotary blade of FIG. FIG. 4 shows the mounting state of the rotary blade of FIG. 1. FIGS. 4A and 4B are cross-sectional views of the rotary blade showing that the grounding tool and the rotary blade bent portion are different. FIG. Figure 5 is a top arrow view of the rotary blade of FIG. FIG. 6 is a side action diagram of the rotary blade of the present invention. FIG. 7 is an enlarged side view of the rotary blade of the present invention. 8A is a side action diagram of a conventional rotary blade. FIG. 8B is a side action diagram when submerged in the ground. FIG.

Hereinafter, an embodiment of a brush cutter according to the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the engine 1 is mounted at the rear end of the brush cutter A, the rotary blade 3 is provided at the tip of the main pipe 2, and the rotation of the engine 1 is transmitted to the rotary blade 3. An operator enters the middle part and performs work. The brush cutter A is held by a hanging metal fitting 4 provided on the main pipe 2 and hung on the shoulder by a shoulder band 5 fixed at a substantially center of gravity. Further, the handle 6 fixed to the main pipe 2 is gripped, and as shown in FIG. 2, the grounding two-point support by the cutting blade pressing tool 9 of the rotary blade 3 and the bent portion 13 formed on the rotary blade 3 is performed from right to left. And weed the weeds about 1 m away in a circular arc and move forward.

As shown in FIG. 2, the rotary blade 3 is sandwiched between the cutting blade receiver 8 of the gear case 7 at the tip of the main pipe 2 of the brush cutter A and the cutting blade presser 9 at the center of the rotary blade 3 with a rotary blade set screw 10. It is fixed.

As shown in FIGS. 3 and 4, the rotary blade 3 has a chip 12 welded to a chip mounting tooth 11 a provided on the outer periphery of the disk-shaped substrate 11 by brazing or the like. In the rotary blade 3, the lower surface 12 a of the chip is bent upward on the outer periphery with respect to the rotary blade mounting surface 11 b to form a circular bent portion 13 that is continuous near the outer periphery of the disk-shaped substrate 11. A cutout portion 11c is formed on the outer periphery of the plate-like substrate 11 because it has a large number of protruding chip attachment teeth 11a. For this reason, in order to form the continuous circular bending part 13, it is good to form in the outermost position which does not contain this notch part 11c.

The angle of bending of the rotary blade 3 is slightly different depending on the height of the cutting blade presser 9 provided below the rotary blade mounting surface 11b serving as a grounding tool. FIG. 4A shows a gap S1 that opens outwardly about 5 degrees with respect to the ground G to the outside of the bent portion 13 when bent about 10 degrees above the outer periphery with respect to the rotary blade mounting surface 11b. The tip of the chip lower surface 12a has a height of about 3 mm from the ground G.

FIG. 4B shows a disk-shaped substrate 11 in which the rotary blade 3 is bent one step from the rotary blade mounting surface 11b in a stepped manner, and the lower surface 12a of the tip is located above the outer periphery of the rotary blade mounting surface 11b. This is another embodiment in which a continuous circular bent portion 13 is formed on the outer periphery. In this embodiment, the height of the cutting blade presser 9 provided below the rotary blade mounting surface 11b to be a grounding tool is higher than that of FIG. When the sheet is bent at about 17 degrees, a gap S1 that opens outward at about 7 degrees is formed outside the bent portion 13, and the tip of the chip lower surface 12a is about 3 mm above the ground G. ing.

Further, an outwardly opening gap S1 is formed between the lower surface of the chip lower surface 12a of the rotary blade 3 and the ground, and an inward gap S2 is formed on the side of the bent portion 13 in the axial direction of the rotary blade 3.

Further, as shown in FIG. 4 (c), the tip lower surface 12a tip of the tip outer peripheral tip 14 of the rotary blade 3 is located outward from the tip upper surface 12b tip.

Next, the usage method of the brush cutter A which has such a rotary blade 3 is demonstrated. As shown in FIG. 1, the rotary blade 3 is attached to the main pipe 2 in front of the operator, and is formed on the ground G in the cutting blade presser 9 of the rotary blade 3 and the rotary blade 3 as shown in FIG. 2. Grounded by two points of the portion 13. In this embodiment, the cutting blade presser 9 is also used as a grounding tool, but a grounding tool may be separately installed at the same position.

When the rotation of the engine 1 is transmitted to the rotary blade 3, the rotary blade 3 rotates in the left direction. The main pipe 2 is swung from the front of the operator in the direction of the swing L, that is, from right to left, so that weeds and the like are mowed between the mowing ranges W. At this time, since the ground G is grounded by the two points of the cutting blade pressing tool 9 of the rotary blade 3 and the bent portion 13 formed on the rotary blade 3, the cutting edge of the rotary blade is always at a constant height with respect to the ground. Stable mowing can be done by sliding the ground while holding. Therefore, since the operator can concentrate on moving forward while swinging the handle left and right, the worker can work lightly with less fatigue.

The numbers in parentheses on the outer periphery of the rotary blade 3 shown in FIG. 5 are the rotary blades at the time of brushing work when the cutting blade presser 9 and the bent portion 13 of the rotary blade 3 shown in FIG. 3 and the height of the ground G are shown. When the middle of the cutting range W is set to 0 mm, when the practical cutting start is set to 5 mm and the cutting end is set to 5 mm, the opposite side of the cutting range W is 20 mm, the opposite side of the cutting start is 15 mm, the cutting end This is to explain that the opposite side is 15 mm.

At this time, as shown in FIGS. 5, 6 and 7, the chip lower surface 12 a is bent upward at the bent portion 13, and an outwardly extending gap S <b> 1 is formed between the ground G and the chip lower surface 12 a. The cutting edge always keeps an upward inclination, so that it does not collide with the side surface of the tip 12 or the notch portion 11c of the tip mounting tooth 11a with a small stone or the like on the ground. . Moreover, since the space | interval of the ground G and the chip | tip lower surface 12a becomes large gradually after a cutting | disconnection, a pebble etc. are pressed down completely and the contact with a chip | tip reduces.

Further, the brush cutter A is swung in the L direction while the rotary blade 3 is slid along the ground G by the cutting blade presser 9 and the bent portion 13 of the rotary blade 3, and the cutting is performed as shown in the enlarged side action diagram of FIG. Acts as an upward component force F that is lifted upward by the rotational energy of the rotary blade 3 and the gradient of the tip outer peripheral tip portion 14 on weeds and the like that are cut at the forward direction L of the cutter A and the lower end tip of the tip lower surface 12a. become. Moreover, since the force which pushes back along the inclination works on the chip lower surface 12a, it is easy to cut even weeds with weak stems, and it is possible to eliminate uncut leaves.

As shown in FIG. 5, at the tip of the tip 12, the tip lower surface 12a is inclined upward toward the upper periphery, so that the tip of the rotary blade 3 has an upward component force F, so that the work can be performed without entering the ground. It can be performed. In addition, the tip lower surface 12a is inclined upward with respect to the rotary blade mounting surface 11b, and as a result, the overall position of the tip 12 from the ground G is increased, but the grass cutting position of the tip 12 is the tip lower surface 12a. Conventionally, since the chip upper surface 12b of the chip 12 is the grass cutting position, the cutting height is not much changed.

FIG. 8 (a) shows a conventional working method, in which the brush cutter A is lifted and held, so that the height of the rotary blade 3 is unstable. Further, the tip of the tip 12 is lowered forward, and the first contact with the weeds is above the tip of the tip, so that a component force runs on the top surface of the tip and the weeds are chased by the wind speed of the rotary blade 3 and escape. Further, as shown in (b), in the operation where the tip end part is submerged in the soil, a part of sand or weed stagnates in the notch part 11c of the tip attaching tooth 11a, and the back face of the tip attaching tooth 11a is abnormal. Wear marks m due to wear occur.

3 and 4 are grounded at two points: a bent portion 13 formed in a circular shape near the outer periphery of the rotary blade 3 and a cutting blade presser 9 provided below the bent portion 13 and the rotary blade 3. In this case, an outwardly extending gap S1 is formed between the ground G and the chip lower surface 12a with the bent portion 13 as a boundary, and an inward gap S2 is formed in the immediate vicinity of the bent portion 13. Is moved forward, sand or the like to be accumulated in the gap S1 can immediately escape over the branch portion 13 toward the cutting blade presser 9 and is generated on the back surface of the tip mounting tooth 11a as described above. This has the effect of preventing the chip 12 from falling off due to abnormal wear. Further, the bent portion 13 and the cutting blade presser 9 as a grounding tool are grounded in a dot shape, and can follow the unevenness of the ground G finely and lightly.

As shown in FIG. 3, the disk-shaped board | substrate 11 has the chip | tip attachment tooth | gear 11a on the outer periphery, and the chip | tip 12 is brazed to each tooth | gear 11a. The mounting pitch of the chip 12 to the chip mounting teeth 11a is about 20 mm, a notch 11c is provided on the front surface of the chip, and a support 11d for receiving the impact of the chip is provided behind the chip. Opening the front of the tip with a large opening increases the chance of encountering the tip with weeds and the like, thereby increasing the cutting ability. However, the support portion 11d needs to leave at least ¼ between the chips 12 in order to radiate heat at the time of brazing or polishing, and to reinforce the impact receiving force on the chips 12 at the time of cutting.

Regarding the creation of the bent portion 13 of the rotary blade 3, a press is formed so as to form a circular shape that is continuous to the outermost side, not in the notch portion 11 c, immediately inward of the notch portion 11 c of the rotary blade 3 shown in FIG. 3. What is necessary is just to bend by processing etc. Similarly, it may be squeezed out by bead processing or the like so as to form a circular shape that is continuous with the outermost side that does not engage with the notch portion 11c, immediately inward of the notch portion 11c of the rotary blade 3. Furthermore, a conventional rotary blade having a bent portion 13 is additionally manufactured by using a press or the like to form a circular shape continuous to the outermost side that does not hang on the notch portion 11c on a flat plate-like rotary blade having a chip on the outer periphery. Is also possible.

As described above, the present invention can ensure work safety, improve work accuracy, and reduce worker fatigue, and thus provides a safe, efficient and more durable brush cutter. I can do it.

A Brush cutter 1 Engine 2 Main pipe 3 Rotating blade 4 Hanging bracket 5 Shoulder band 6 Handle 7 Gear case 8 Cutting blade holder 9 Cutting blade presser 10 Rotating blade set screw 11 Disk-shaped substrate 11a Tip mounting tooth 11b Rotating blade mounting Surface 11c Notch portion 11d Support portion 12 Tip 12a Tip lower surface 12b Tip upper surface 13 Bending portion 14 Tip outer peripheral tip G Ground S1 Gap S2 Gap F Upward component force L Swing direction W Cutting range m Wear trace

Claims (1)

It consists of a center part having a flat surface and an inclined outer peripheral edge part that is connected upward via the central part and the bent part, and a large number of chip mounting teeth with notches and chips attached to the inclined outer peripheral part are alternately formed. A rotary blade is provided, and a circle forming the bent portion is configured to be positioned in the immediate vicinity of the inside of the notch portion, and is positioned below the rotary blade and a cutting blade receiver positioned above the rotary blade. the rotary blade is clamped by the cutting blade retainer, when at the same time is grounded the rotary blade and the cutting blade retainer, chip lower surface with grounded at two points of the bent portion and the cutting blade retainer always A brush cutter configured to maintain an upward inclination .

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