JP2012029668A - Entanglement prevention structure in bush cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bush cutter for cutting bushes or weeds which is capable of preventing entanglement of foreign matter such as cut weeds with rotating parts.SOLUTION: In mounting plate-shaped rotating blade such as a chip saw, a circular saw blade, and a cutting blade at the end part of a rotating shaft protruded from a body, with the rotating shaft being fixed to the end of a shaft of a bush cutter and rotationally driven by a drive source such as a motor and a fuel engine, a cylindrical part to prohibit intrusion of foreign matter is inserted between a blade receiving metal fitting and the plate-shaped rotating blade where foreign matter tends to be entangled, thus preventing entanglement of foreign matter such as cut weeds. In using a linear blade rotating unit type device including a flexible linear blade such as a nylon cord projecting outward, a unit including a cylindrical structure to prohibit foreign matter added to a conventional device is used at a part where foreign matter tends to be entangled, thus preventing entanglement of foreign matter such as cut weeds. The new structure may be molded integrally when the unit is manufactured, or it may be additionally attached (e.g., integrated by adhesive agent, screw structure, or the like) afterwards. A similar structure may otherwise be employed.

Description

With regard to a brush cutter that attaches a plate-like rotary blade or linear blade rotary unit to a rotary shaft protruding from the main body fixed to the shaft tip of the brush cutter and performs weed cutting by this rotation, It is an invention related to an entanglement preventing structure for preventing the entanglement of the rotating shaft.
[Selection diagram] FIGS. 1 and 2

In order to cut weeds, brush cutters that perform cutting work with a rotating blade that rotates at high speed have been put into practical use. In this type of brush cutter, foreign matter such as cut grass or dust on the work site is entangled with the rotating shaft, causing a situation that hinders work. Means for preventing entanglement have been devised to cope with such a situation.

In Patent Document 1, a rotary shaft protection member is attached to a rotary shaft, and a blade portion is formed on a part of the rotary shaft protection member, thereby cutting grass that is about to enter the rotary shaft portion. The idea of preventing entanglement is disclosed. Patent Document 2 has the idea of providing a flange-type entanglement preventing member to prevent foreign matter from entering the rotating shaft portion of the blade plate. Patent Document 3 does not allow vine grass or the like to wind around the rotating shaft. As described above, a concept is disclosed in which a triangular plate-like member is disposed between the support rod and the cutting blade surface so as to be close to the blade surface, and the suspension of the cutting blade and the like prevents the rotating shaft from rotating around the rotating shaft. Yes.

Japanese Patent Laid-Open No. 11-18543 Japanese Patent Laid-Open No. 11-168939 Japanese Patent Publication No. 2001-103824

With the idea of cutting what is entangled by a cutting blade as disclosed in Patent Document 1, entanglement cannot be prevented if the cutting blade (blade part) is not cut. In addition, it is impossible to prevent foreign matter or cut grass that has entered inside the cutting blade from being entangled with the rotating shaft, and the structure itself is complicated, so that the cutting blade is dangerous for the operator.
As disclosed in Patent Documents 2 and 3, in the structure that excludes the foreign matter reaching the rotating shaft, the gap between the fixed entanglement preventing member and the rotating blade plate cannot be completely eliminated. There is a drawback that it may intrude and cannot always effectively prevent entanglement.

In view of the above-described drawbacks of the prior art, the present invention is intended to realize a structure that can prevent grass cut by a simpler structure from being entangled with a rotating shaft.

In order to achieve the above object, a brush cutter embodying the present invention protrudes from a main body fixed to a shaft tip, and has a plate-like rotary blade or the like at the tip of a rotary shaft that is driven to rotate by a power source such as a motor or a fuel engine. A linear blade rotating unit is installed, and weeds are cut by the rotation.

Foreign matter such as grass that has been cut is caught and entangled on a rotary shaft between the plate-like rotary blade or linear blade rotary unit and the main body skirt. The reason for this is that the cut grass is generally wound at a right angle to the rotation axis from the periphery of the rotation axis.

Therefore, if a structure that prevents the movement of the foreign matter is disposed between the foreign matter and the rotating shaft, the foreign matter can be prevented from being entangled with the rotating shaft. The structure is simple and practical with a cylindrical structure that sufficiently covers the rotational axis range in which foreign matter may be entangled.
[Selection] Figure 3

In the above brush cutter, when a plate-like rotary blade is used, a cylindrical shape is formed between the plate-like rotary blade attached to the rotary shaft and the blade holder of the main body (the radius of the cylindrical portion is larger than the radius of the lower end skirt of the main body). By sandwiching the component 1 having a large size, the cylindrical portion prevents entanglement of foreign matter such as cut grass on the rotating shaft.
[Selection] FIGS. 4 and 5

In addition, when using a linear blade rotation unit in a brush cutter, the linear blade rotation unit with a cylindrical structure (the radius of the cylindrical portion is larger than the radius of the lower end skirt of the main body) is used to cut the brush. The cylindrical structure prevents entanglement of foreign matter such as grass on the rotating shaft.
[Selected Figures] FIGS. 6 and 7

According to the entanglement preventing structure of the brush cutter of the present invention according to claim 1, when grass or a foreign object cut by the plate-like rotary blade is caught in the rotary shaft, most of it is from the periphery of the rotary shaft to the rotary shaft. Since it is wound at a right angle, it can effectively prevent the foreign matter from colliding with the cylindrical portion rotating at a high speed of the present invention and being entangled with the rotating shaft.

According to the entanglement preventing structure of the brush cutter of the present invention as set forth in claim 2, even when grass or foreign matter cut by the linear blade rotating unit is caught in the rotating shaft, most of it is transferred from the periphery of the rotating shaft to the rotating shaft. Since it is wound at right angles to the cylinder, it is possible to effectively prevent the foreign matter from colliding with the cylindrical portion rotating at a high speed of the present invention and entangled with the rotating shaft.

I tried to make an equivalent structure integrated with an adhesive in an existing unit that is actually sold.
I have tried using it under various conditions, but no problems have occurred so far, such as grass getting into contact with rotation.
[Selection] Figure 8

FIG. 1 is an equipment configuration diagram when a plate-like rotary blade is mounted on a brush cutter. Fig. 2 shows the equipment configuration when the linear blade rotating unit is mounted on the brush cutter. Fig. 3 shows the mechanism of entanglement of grass and other foreign matter on the grass rotation shaft and the mechanism for preventing it. FIG. 4 shows the invention when a plate-like rotary blade is used (cylindrical structure). Fig. 5 is an invention part related to part 1 plate-like rotary blade FIG. 6 is an invention related to a linear blade rotating unit (addition of a cylindrical structure). Fig. 7 shows the invention part related to part 2 linear blade rotation unit Figure 8 shows an example of a prototype using the existing linear blade rotation unit (the mouse color part). Figure 9 shows the blade bracket FIG. 10 is an invention related to a linear blade rotating unit (addition of a cylindrical approximate structure). FIG. 11 is an invention related to a linear blade rotating unit (addition of a cylindrical approximate structure).

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a structure for preventing entanglement in a brush cutter according to the present invention will be described with reference to the accompanying drawings. When a brush cutter is used with a plate-like rotary blade attached, the plate-like rotary blade is normally inserted into the blade receiving bracket convex portion at the shaft tip from the tip of the rotary shaft and fixed with a special nut. When working such as mowing, foreign matter may get entangled between the skirt at the tip of the shaft of the brush cutter and the plate-like rotary blade, causing the rotation speed of the plate-like rotary blade to drop or stopping rotation, which may hinder the work. It happens a lot. To remove the tangled foreign matter, first stop the motor and engine, remove the brush cutter from the shoulder band, and remove the foreign matter. Therefore, when such a situation occurs, work efficiency is greatly reduced. In addition, it may be dangerous if the scaffolding is poor. In order to avoid this, before starting the mowing operation, the cylindrical invention part 1 is sandwiched and fixed with a nut between the blade receiving metal projection at the tip of the shaft and the plate-like rotary blade. As a result, the probability that the foreign material gets entangled in the gap between the skirt portion and the component 1 is greatly reduced. If it is very unlikely to occur but is unlucky, the foreign matter will be removed by the same procedure as before. Even if the work is completed without any foreign matter tangled, there may be a small amount of fine grass or mud in the gap, so remove the parts and remove the foreign matter attached to the blade bracket or rotating shaft. It is desirable to implement as part of the maintenance.
[Selected Figures] FIGS. 4 and 9

When a brush cutter is used with a linear blade rotating unit type device, the linear blade rotating unit is usually fixed to a blade bracket at the end of the shaft while rotating the linear blade rotating unit from the end of the rotating shaft. When working such as mowing, foreign objects get entangled in the gap between the skirt portion at the tip of the shaft of the brush cutter and the linear blade rotation unit, and the rotation speed is reduced or the rotation is stopped.
To remove the tangled foreign matter, stop the motor and engine, remove the brush cutter from the shoulder band, and remove the foreign matter. Therefore, when such a situation occurs, work efficiency is greatly reduced. In addition, it may be dangerous if the scaffolding is poor. Therefore, when starting the mowing operation, the linear blade rotating unit to which the cylindrical structure of the present invention is added is fixed to the tip of the blade receiving bracket at the tip of the shaft. As a result, the probability that foreign matter gets entangled in the gap between the skirt and the unit is greatly reduced. If it is very unlikely to occur but is unlucky, the foreign matter will be removed by the same procedure as before. Even if the work is completed without any foreign matter tangled, there may be a small amount of fine grass or mud in the gap, so remove the unit and remove the foreign matter attached to the blade bracket, rotating shaft, unit, etc. Should be implemented as part of equipment maintenance.
[Selection] FIGS. 6 and 9

Claims (2)

Project from the main body fixed to the shaft tip of the brush cutter, and attach a plate-like rotary blade such as a tip saw, circular saw blade, or cutting blade to the tip of the rotating shaft that is driven to rotate by a power source such as a motor or a fuel engine. In a brush cutter that cuts weeds and the like by rotating the cutting blade, the blade has a cylindrical shape 1 (the radius of the cylindrical portion is larger than the radius of the lower end skirt of the main body) that prevents foreign matter from entering the part where the foreign matter is entangled. A structure for preventing entanglement in a brush cutter, wherein the structure is sandwiched between a metal fitting and a plate-like rotary blade.
(Selection diagram) FIGS. 4 and 5 A linear shape in which a flexible linear blade such as a nylon cord protrudes outward from the main body fixed to the tip of the brush cutter shaft and is rotated at the tip of a rotating shaft driven by a power source such as a motor or a fuel engine. Cylindrical structure that prevents foreign matter from entering the part where the foreign matter gets entangled in the brush cutter that attaches the blade rotating unit and cuts weeds by rotating the cutting blade (the radius of the cylindrical part is larger than the radius of the bottom skirt of the main body) A tangling prevention structure in a brush cutter characterized by using a linear blade rotating unit to which) is added.
(Selection diagram) FIGS. 6 and 7