WO2000032025A1

WO2000032025A1 - Extendable rotary knife and its blades

Info

Publication number: WO2000032025A1
Application number: PCT/JP1999/004098
Authority: WO
Inventors: Yutaka Kanemaru
Original assignee: Yutaka Kanemaru
Priority date: 1998-11-30
Filing date: 1999-07-30
Publication date: 2000-06-08
Also published as: AU4930899A

Abstract

An extendable rotary knife wherein the durability of a blade mounting structure is increased remarkably by applying a load uniformly on an entire blade and an erroneous dropping of the blade from the rotary knife can be prevented by providing a sufficient sharpness and sweeping width, whereby recessed parts (11) which are recessed inward from a circle C formed by connecting the pivot shafts (3) of the blades (2) are formed linearly in a rotating body (1) at an angle of α which is over a right angle relative to the blades (2) extending in a normal line direction.

Description

Meso Fine Swing-type rotary blade and its blade

The present invention relates to a rotary blade used for a brush cutter for cutting grass and the like, a shredder for feed, and the like, and particularly to a so-called swing-type rotary blade having a blade rotatably mounted. is there. In the present application, the blade refers to a portion that constitutes a cutting edge portion of a rotary blade and collides with grass or the like to cut it. Background art

Conventionally, there are various types of brush cutters used to cut grass and weeds, from large self-propelled cutters to small shoulder-mounted cutters, but most of the blades used are rotary blades. . Many of the shredders that cut pasture for feed use rotary blades.

As a typical example of a conventional swing-type rotary blade, as shown in FIG. 7, several blades 9 2 are radially provided on the outer periphery of a circular disk-shaped rotary body 91. When the rotating body 91 is rotated, the centrifugal force causes the blade 92 to swing out and collide with the grass while maintaining the normal direction, thereby cutting the blade. The inventor of the present application observed the state of mowing by the conventional swing-out rotary blade with a high-speed camera. As a result, the following situations were confirmed.

(1) The grass to be cut is once located between the blades 92 and 92, and hits the arc of the rotating body 91 before being cut off by colliding with the blades. Therefore, a protruding state is formed between the blades 92 and 92. The grass that hits the circular arc portion collides only with the tip of the blade 92, so that the area of mowing by the blade 92 is naturally reduced, and the impact moment on the tip of the blade 92 is increased.

(2) Due to the centrifugal force, the blade 92 keeps a state almost along the normal line, and the blade surface is almost perpendicular to the direction of collision with the grass. However, the sharpness increases when the vehicle collides with the grass with a certain swept angle and cuts off.

From the above-described situation, the conventional swing-out rotary blade in which the blade 92 is attached to the mere disk-shaped rotary member 91 has the following problems.

① The cutting area is narrower than the blade length.

(2) Only the tip of the blade is severely worn.

(3) Since the impact momentum is large, the load on the blade mounting part increases.

④Sufficient sharpness cannot be obtained. The applicant has indicated “rotary blade and its blade” in PCT / JP98 / 053392 (hereinafter “the earlier application”). In this application, a rotating blade composed of a blade formed of a relatively soft material and a rotating body to which the blade is attached is shown. A rotating blade having a fixed mounting angle and a swing-out type that is rotatable. There is something.

The present invention further improves the swing-out type rotary body among the rotary blades shown in the previously filed invention, and solves these problems of the prior art. The purpose of this blade is to provide a rotating blade that evens out the load on the entire blade and improves durability, while providing sufficient sharpness and mowing width, and has a durable blade mounting structure. Very good in terms of sex, rotating It has a structure that can prevent accidental dropping from the body. Disclosure of the invention

For this reason, in the present invention, in a swing-type rotary blade comprising a rotating body whose center portion is connected to a drive shaft and rotates, and a blade rotatably supported on an outer peripheral portion of the rotating body, Is formed such that there is a portion depressed toward the center of the rotating body from an arc connecting between the respective pivots of the blade around the center of rotation of the rotating body at the outer peripheral portion of the rotating body. As a result, the mowing plants enter the recesses and collide with the blades and are cut off, so that they collide with the entire blades, thereby obtaining a sufficient mowing width and eliminating the concentration of partial impact on the blades. .

Also, a blade attached to the rotating body of the above-mentioned swiveling rotary blade, which is formed at one end of the blade and inserted into a shaft support shaft of the rotating body to hold the blade rotatably. In the blade mounting structure, an insertion hole formed in the one end of the blade, and a communication pipe inserted into the communication hole and having upper and lower portions formed to be larger than the diameter of the insertion hole. It is designed to be composed. As a result, the impact applied to the blade and transmitted to the shaft is dispersed by the through pipe and does not concentrate on the insertion hole, so that the durability of the blade can be extended. If this is a structure in which a through hole is simply drilled at the end of the blade, the impact concentrates on the insertion hole and becomes oval due to abrasion with the shaft, causing damage in a short period of use. Risk of falling off. In this regard, in the blade of the present invention, the impact can be dispersed by the presence of the through pipe, and the wear of the insertion hole can be extremely suppressed. If the user disregards the description in the manual (hereinafter “excessive use”), etc., even if the pipe may break, the damage to the hole immediately Because it does not reach, blade scattering accident Can be prevented beforehand. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a plan view showing a rotary blade of Example 1, FIG. 2 is a perspective view showing a blade of Example 1, and FIG. 3 is a side sectional view of the blade shown in FIG. FIG. 4 is a perspective view of the rotating body of the first embodiment, FIG. 5 is a plan view of the blade of the second embodiment, and FIG. 6 is a plan view of the rotary blade of the third embodiment. FIG. 7 is a plan view of a conventional rotary blade. BEST MODE FOR CARRYING OUT THE INVENTION

The rotary blade according to the present invention is a swing-type rotary blade composed of four blades 2 rotatably mounted on a rotary body 1 and fixed to a driving portion of a brush cutter (not shown). What is used. The shape of the rotating body 1 is different from the conventional circular one, and as shown in FIG. 1, a concave portion 11 is formed which is recessed inside a circle C connecting the shaft 3 of the blade 2. c In addition, the concave portion 11 is formed in a straight line, and forms an angle α that is equal to or greater than a right angle with the blade 2 projecting in the normal direction. When the rotary blade is rotated for mowing, these concave portions 11 and the angle string determine the mowing ability of the blade 2. In other words, the grass that has entered the concave portion 11 collides with the blade 2 at an angle, so that proper mowing is performed. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Example 1

In the first embodiment, a blade made of the abradable material shown in the earlier application was used for the rotating body 1 described above.

First, as described above, the shape of the rotating body 1 is such that the concave portion 11 shown in FIG. It was made. To describe the planar shape of the rotating body 1 of this embodiment in more detail, it is necessary to form a shaft support portion 13 protruding at one end of each side of a square formed by an imaginary line coinciding with the concave portion 11. As a result, a recess 11 is formed inside a circle C connecting the shafts 3. In addition, since a part of the pivot portion 13 coincides with the extension of each of the adjacent sides, the concave portion 11 has a linear shape, and an angle is formed between the concave portion 11 and the blade 2.

As shown in FIG. 4, the three-dimensional shape of the rotating body 1 is such that an upper surface rotating plate 1 a and a lower surface rotating plate 1 b having substantially the same shape are fixed to each other with a shaft 3 interposed therebetween. The rotating shaft 3 of this embodiment is formed of stainless steel and is screwed up and down.

As shown in FIG. 2, the blade 2 is made of a wear-resistant material in which the cutting edge portion 21 is formed by laminating the wear material and the non-wear material described in the earlier application. The mounting portion 2 attached to 1 is formed of a hard material such as iron. An insertion hole 23 is formed at an end of the mounting portion 22, and an insertion tube 24 is inserted into the insertion hole 23.

As shown in FIG. 3, the insertion tube 24 has a shape in which the upper and lower ends are formed to have a wide mouth, and the outer diameter of the upper and lower ends is larger than the inner diameter of the through hole 23 and the outer diameter of the central portion. Is formed smaller than the inner diameter of the insertion hole 23. Therefore, although there is a gap as a play between the insertion hole 23 and the communication pipe 24, the upper and lower ends are wide, so that they do not come off from the insertion hole 23.

In addition, the outer diameter of the supporting shaft 3 is set to be smaller than the inner diameter of the narrowest part of the communicating tube 24 by passing the supporting shaft 3 through the communicating tube 24. Because of the small size and the gap between the rotating body 1 and the upper and lower ends of the communication pipe 24, the blade 1 is rotatably supported on the shaft. It is possible to change the angle with respect to the rotating surface, and the impact load is dispersed. (4) It is possible to minimize the intensive impact load on the through holes 23. As a result, the wear of the through holes 23 is minimized, and there is no danger of the blades 2 scattering during work. In particular, in this embodiment, the support shaft 3 is made of hard stainless steel, while the through pipe 24 is made of mild steel. is there. Therefore, even if the insertion tube 24 breaks, the through hole 23 remains, so that the blade does not scatter.破断 It is possible to notice daily breakage of the pipe 24 by daily inspection or the generation of abnormal noise.

In addition, the change in the angle of the blade 1 with respect to the rotation surface also reduces the impact of the blade 1 on the ground surface, which is effective in preventing rock erosion.

Next, a state when the grass is cut by the rotary blade of the present embodiment will be described.

As described above, in the rotating state, the blade 1 is stable while following the normal direction (radial direction). Once the mowing begins, the grass enters the recess 11 and moves along its surface, colliding near the base of blade 2 and then moving along blade 1. This causes blade 1 to cut through the grass.

Here, the same mower was used to compare the mowing with the rotary blade of the prior art described above by mowing grass under the same conditions.

In the mowing with the rotary blade of the present embodiment, a mowing width of about 30 cm from the tip of the blade to the tip of the opposing blade was obtained by a single mowing operation. In addition, since the blade 1 wear due to the mowing work proceeds in an oblique direction, the knife shape is maintained as shown in the previous application, and the large mowing width and efficient mowing work are maintained until the end. Was maintained.

On the other hand, in the conventional rotary blade of a circular disk, Despite the same width to the tip of the opposing blade, which was about 30 cm, the cutting width was only about 20 cm, and the cutting performance was poor. Grass that could not be cut remained. In addition, when observing the state of wear of the blade during the mowing operation, it can be seen that almost only the vicinity of the tip is worn, and that the impact applied to the tip is strong. This was about one-third that of the example. Example 2

In the second embodiment, a blade 4 used for a swing-out rotary blade is shown. The blade 4 has a metal cutting edge portion 41 for cutting off relatively hard plants such as seeds, kaya or reeds.c. The so-called circular saw-type chip saws used in this study were used, but this steel tip saw the risk that stone particles or fragments of blades would be scattered by collision with stones or blocks. . In this regard, the blade 4 of the present embodiment is a metal blade for forming a swing-out rotary blade that does not have the danger of breaking stones or blocks or chipping the blade itself. The blade 2 shown in the above embodiment can be used to prevent the scattering of stone grains or blade fragments. However, when used on land where hard vegetation grows, the blade 2 consumes a great deal of energy and provides sufficient work efficiency. I can't.

As shown in FIG. 5, the cutting edge portion 41 of the blade 4 has been sharpened in a wave shape. This corrugation is formed with a slope that gradually recedes toward the cutting edge portion 41a. Thus, when colliding with a hard plant, the plant can be cut off without excessively catching on the stem thereof and while generating an appropriate resistance. In particular, since the metal blade 4 can obtain a sufficient inertial force due to its own weight, the above-described hard It produces optimal resistance to cutting vegetation and can be cut off.

Further, since the mounting portion 42, the insertion hole 43, and the insertion tube 44 are the same as the blade 2 of the first embodiment, the impact load transmitted to the shaft support structure is dispersed, and the rotation of the blade 4 is performed. It is an effective avoidance measure when the movement hits a stone. That is, although the impact force against the stone or the like increases as the inertia force of the blade 4 increases, the impact is dispersed by the shaft support structure, and high durability can be obtained. On the other hand, unlike a super-steel chip saw, when it collides with a stone or a block, the blade 4 rotates and retreats, and the colliding side and the crushed side are not chipped and scattered.

It should be noted that the rotary blade of the prior art shown above could hardly mow, and was out of comparison. Example 3

In the third embodiment, the rotating body 1 shown in the first embodiment has a different shape.

As shown in FIG. 6, in the rotating body 5 of the third embodiment, three bearing portions 53 protrude radially, and here each blade 2 is supported by the supporting shaft 55. It is supported and installed. A concave portion 51 is formed in the circle connecting the shafts 55 between the respective shaft portions 53, and the front surface 53a of the shaft portion 53 is formed linearly. The front 53a and blade 2 form an angle of 90 degrees or more.

Therefore, in the rotary blade according to the third embodiment, a large amount of grass entering the concave portion 51 having a large area moves along the front surface 53a and collides with the blade 2 to be cut efficiently. Hard plants can also be knocked down by this protruding shaft support 53. Since the present invention is configured as described above, a brush cutter having the following characteristics can be configured.

(1) Plants such as grass to be trimmed can efficiently collide with the entire blade, and a sufficient trimming width can be obtained.

(2) The angle of collision between the blades of plants, such as grasses, and the blade can be obtained appropriately, and the plants can be cut off. Therefore, sufficient sharpness can be obtained.

(3) Since the collision surface between the blades such as grass and plants is wide, it becomes an inclined abrasion surface and can maintain its sharpness, and the abrasion rate is smaller than that of the conventional rotary blade.

(4) The impact load applied to the blade support portion of the blade can be dispersed, and the durability of the shaft support portion can be enhanced. For this reason, even if the blade is used excessively, it is possible to prevent the blade from scattering.

(5) Even in collisions with the ground surface, the angle of the blade can be flexibly changed, and not only damage to the blade itself, but also scattered stones can be minimized. Industrial availability

As described above, the blade for a brush cutter according to the present invention and the blade thereof can be applied to various brush cutters, from a large-sized self-propelled brush cutter to a small shoulder-type brush cutter. By selecting the most appropriate form of use according to the conditions of the place where the cutting is performed, safe and efficient mowing can be performed.

Claims

The scope of the claims ,

1. In a swing-type rotary blade composed of a rotating body having a central portion connected to a drive shaft and rotating, and a blade rotatably supported on an outer circumferential portion of the rotating body, an outer circumferential portion of the rotating body is provided. A swing-type rotary blade, characterized in that there is a portion that is recessed toward the center of the rotating body from an arc connecting the respective shafts of the blade around the rotation center of the rotating body.

2. A recess is formed in the center of the rotator from the position of the fulcrum, and a recess is formed at the back of the rotation axis of the rotor from the rotation axis of the blade. 2. The swing-out rotary blade according to claim 1, wherein a straight line is formed near a shaft support axis of another blade located at the position (1).

3. A blade attached to the rotating body of the swing-out rotary blade according to claim 1, wherein the blade is formed at one end of the blade and inserted into a shaft support shaft of the rotary body to hold the blade rotatably. In the above blade mounting structure, the blade comprises a through hole formed at the one end of the blade, and an insertion tube inserted into the insertion hole and having upper and lower portions formed to be larger than the diameter of the through hole. A blade for a rotary blade, characterized in that:

4. The blade for a rotary blade according to claim 3, wherein a gap is provided between an inner peripheral surface of the through hole and an outer peripheral surface of the insertion tube.

5. The blade for a rotary blade according to claim 3, wherein the through pipe is formed of mild steel softer than the shaft.

6. A blade attached to the rotating body of the swing-out rotary blade according to claim 1, having a mounting structure formed at one end of the blade and inserted into a shaft support shaft of the rotating body to hold the blade rotatably. In the blade of the swing-out rotary blade, a blade _c for the rotary blade is characterized in that a blade edge portion of the blade is formed in a wave shape of metal, and the wave shape is a wave shape in which the wave shape gradually retreats.

7. One end of each side of a square in a swing-type rotary blade composed of a rotating body whose center portion is connected to a drive shaft and rotates, and a blade rotatably supported on the outer periphery of the rotating body. A swing-out rotary blade that forms a shaft support portion protruding to the side, and that a part of the shaft support portion coincides with an extension of each adjacent side.