JP2024092468A - Bush cutter - Google Patents

Abstract

To provide a bush cutter that makes it possible to cut a part slightly above a root of a plant, etc. and the root in one operation.SOLUTION: A bush cutter 1 comprises: cutting blade section 2 including a rotary upper cutting blade 2A and a rotary lower cutting blade 2B, with their provided in two upper/lower stages, the cutting blade section 2 including the upper cutting blade 2A with a diameter larger than the lower cutting blade 2B; a power section 3 generating power for driving the upper cutting blade 2A and the lower cutting blade 2B; a hollow shaft 4 with the power section 3 provided at one end and the cutting blade section 2 provided at the other end; and a power transmission shaft built in the hollow shaft 4 and transmitting the power of the power section 3 to the upper cutting blade 2A and the lower cutting blade 2B.SELECTED DRAWING: Figure 1

Description

The present invention relates to a brush cutter used for cutting vegetation, etc.

A brush cutter is a machine used to cut vegetation. Generally, a brush cutter has a rotating blade and a power unit that drives the blade, both ends of an operating arm that has a built-in power transmission shaft. The operator operates the operating unit attached to a handle fixed to the middle of the operating arm, and performs work by swinging the tip of the blade from side to side (see, for example, Patent Document 1).

JP 2009-183241 A

Generally, when cutting vegetation, workers do not cut the vegetation from its base all at once, but instead swing the tip of the cutting blade in one direction to cut the vegetation slightly above its base, and then swing the tip of the cutting blade in the opposite direction to cut the vegetation at its base a second time.

The objective of the present invention is to provide a brush cutter that can cut grass slightly above the base of trees and grasses and cut the base of the trees in a single operation.

The brush cutter of the present invention includes a blade section having a rotating upper blade and a lower blade arranged in two stages, one above the other, in which the upper blade has a larger diameter than the lower blade, a power section that generates power to drive the upper blade and the lower blade, a hollow shaft with the power section at one end and the blade section at the other end, and a power transmission shaft that is built into the hollow shaft and transmits the power of the power section to the upper blade and the lower blade.

The brush cutter of the present invention has two rotating blades, an upper blade and a lower blade, and the larger upper blade comes into contact with the grass first, cutting the grass slightly above the base, and then the lower blade comes into contact with the grass and cutting the base.

In the brush cutter of the present invention, it is desirable that the upper cutting blade and the lower cutting blade rotate in opposite directions. This allows the upper cutting blade and the lower cutting blade, which rotate in opposite directions, to cancel each other's reaction torque.

The cutting blade unit preferably has a drive gear provided at the end of the power transmission shaft, a first rotating shaft that rotates the upper cutting blade and intersects with the rotating shaft of the drive gear, a first driven gear that is provided at the end of the first rotating shaft and meshes with the drive gear at the top, a second rotating shaft that rotates the lower cutting blade and intersects with the rotating shaft of the drive gear, and a second driven gear that is provided at the end of the second rotating shaft and meshes with the drive gear at the bottom.

As a result, when the power of the power unit is transmitted to the drive gear by the power transmission shaft, the first driven gear and the second driven gear rotate in opposite directions, causing the first rotating shaft and the second rotating shaft to rotate in opposite directions, respectively, causing the upper cutting blade and the lower cutting blade to rotate in opposite directions.

(1) A brush cutter that includes a blade section having a rotating upper and lower blades arranged in two stages, one above the other, where the upper blade has a larger diameter than the lower blade, a power section that generates power to drive the upper and lower blades, a hollow shaft with the power section at one end and the blade section at the other end, and a power transmission shaft built into the hollow shaft that transmits the power of the power section to the upper and lower blades, allows the upper blade to first cut the area slightly above the base of plants and trees, and then the lower blade to cut the base of plants and trees in a single operation, making it possible to perform brush cutting work efficiently.

(2) Since the upper and lower cutting blades rotate in opposite directions, the counter-rotating upper and lower cutting blades cancel each other's reaction torques, making the operation stable and facilitating mowing.

1 is a side view of a brush cutter according to an embodiment of the present invention. FIG. 2 is a plan view of the cutting blade unit of FIG. 1 . FIG. 2 is a side view showing the configuration inside the gear box of FIG. 1 . FIG. 4 is a side view showing another embodiment of a brush cutter according to the present invention. FIG. 5 is a side view showing the configuration inside the gear box of FIG. 4 .

Figure 1 is a side view of a brush cutter according to an embodiment of the present invention, and Figure 2 is a plan view of the cutting blade of Figure 1.

As shown in FIG. 1, the brush cutter 1 according to the embodiment of the present invention comprises a blade section 2 having a rotary upper blade 2A and a rotary lower blade 2B arranged in two stages, one above the other, a power section 3 that generates power to drive the upper blade 2A and the lower blade 2B, and a power section 3 that is provided at one end and a power section 3 that is provided at the other end.
The lower end of the hollow shaft 4 is connected to a gear box 5 of the cutting blade unit 2.

The upper cutting blade 2A and the lower cutting blade 2B are disk-shaped rotating blades. The upper cutting blade 2A has a larger diameter than the lower cutting blade 2B. For example, if the diameter of the upper cutting blade 2A is 10 inches (255 mm), the diameter of the lower cutting blade 2B is a smaller diameter such as 9 inches (230 mm). The upper cutting blade 2A and the lower cutting blade 2B rotate in opposite directions.

The power unit 3 is composed of a prime mover such as an engine or a motor. The hollow shaft 4 has a built-in power transmission shaft (not shown) that transmits the power of the power unit 3 to the upper cutting blade 2A and the lower cutting blade 3B. In addition, a handle 7 is provided midway through the hollow shaft 4 for the operator to grasp.

FIG. 3 is a side view showing the internal configuration of the gear box 5 in FIG.
The gear box 5 is provided with a bevel gear 10 as a drive gear rotating around a rotation shaft 6 provided at an end of the power transmission shaft, a first rotation shaft 11A that rotates the upper cutting blade 2A, a second rotation shaft 11B that rotates the lower cutting blade 2B, a bevel gear 12A as a first driven gear provided at an end of the first rotation shaft 11A and meshing with the bevel gear 10 at an upper part, and a bevel gear 12B as a second driven gear provided at an end of the second rotation shaft 11B and meshing with the bevel gear 10 at a lower part. The first rotation shaft 11A and the second rotation shaft 11B are perpendicular to the rotation shaft 6 of the bevel gear 10.

With the brush cutter 1 configured as described above, when an operator grips the handle 7 and swings the cutting blade 2 at the tip in one direction F (see FIG. 2), of the rotary upper cutting blade 2A and lower cutting blade 2B provided in two stages, the larger-diameter upper cutting blade 2A comes into contact with the vegetation at contact point _F1 first, cutting the vegetation slightly above its roots, and then the smaller-diameter lower cutting blade 2B comes into contact with the vegetation at contact point _F2 , cutting the vegetation at its roots. In other words, the operator can perform a two-stage brush cutting operation at contact point _F1 and contact point _F2 by simply swinging the cutting blade 2 at the tip in one direction F.

In addition, in the brush cutter 1 configured as described above, the upper cutting blade 2A and the lower cutting blade 2B rotate in opposite directions, so the upper cutting blade 2A and the lower cutting blade 2B, which rotate in opposite directions, cancel each other's reaction torques and become stable, resulting in less vibration and making brush cutting easier.

As shown in FIG. 1, in the brush cutter 1 of this embodiment, the hollow shaft 4 extends diagonally upward relative to the upper cutting blade 2A and the lower cutting blade 2B. Therefore, if the distance between the upper cutting blade 2A and the lower cutting blade 2B is narrow, the upper cutting blade 2A may interfere with the hollow shaft 4 depending on the size of the upper cutting blade 2A.

As shown in Figures 4 and 5, it is possible to make the brush cutter 1A such that the first rotation shaft 11A that rotates the upper cutting blade 2A is oriented so as to intersect obliquely with the rotation shaft 6 of the bevel gear 10 of the drive gear. The second rotation shaft 11B that rotates the lower cutting blade 2B is perpendicular to the rotation shaft 6 of the bevel gear 10. This widens the gap between the upper cutting blade 2A and the hollow shaft 4, preventing the upper cutting blade 2A from interfering with the hollow shaft 4.

The brush cutter of the present invention is useful as a brush cutter used for cutting vegetation, etc., and is particularly suitable as a brush cutter that can cut vegetation slightly above the base and at the base in a single operation.

Reference Signs List 1, 1A Brush cutter 2 Cutting blade section 2A Upper cutting blade 2B Lower cutting blade 3 Power section 4 Hollow shaft 5 Gear box 6 Rotating shaft 10, 12A, 12B Bevel gear 11A First rotating shaft 11B Second rotating shaft

Claims (4)

A blade unit having a rotary upper blade and a lower blade provided in two stages, upper and lower, the upper blade having a larger diameter than the lower blade;
a power unit that generates power for driving the upper cutting blade and the lower cutting blade;
a hollow shaft having the power unit at one end and the cutting blade unit at the other end;
the power transmission shaft is built into the hollow shaft and transmits the power of the power unit to the upper cutting blade and the lower cutting blade. The brush cutter of claim 1, in which the upper cutting blade and the lower cutting blade rotate in opposite directions. The cutting blade portion is
a drive gear provided at an end of the power transmission shaft;
a first rotation shaft that rotates the upper cutting blade and intersects with a rotation shaft of the drive gear;
a first driven gear provided at an end of the first rotating shaft and meshing with an upper portion of the drive gear;
a second rotation shaft for rotating the brush cutting blade, the second rotation shaft intersecting the rotation shaft of the drive gear;
2. A brush cutter according to claim 1, further comprising a second driven gear provided at an end of said second rotating shaft and meshing with said drive gear below said drive gear. The rotation axis of the drive gear and the first rotation axis intersect obliquely,
4. The brush cutter according to claim 3, wherein the rotation axis of the drive gear and the second rotation axis are perpendicular to each other.

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