JP3176579B2 - Brush cutter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an upper blade plate which uses an engine or a motor rotating at a high speed as a power source, reduces the rotation at a large reduction ratio, and rotates the upper and lower blade plates at low speed in opposite directions to each other. The present invention relates to a bush cutter having a lower blade plate and cutting plants and trees like scissors with cutting blades protruding from the outer peripheral portions of two blade plates.

[0002]

2. Description of the Related Art As a rotary drive mechanism of a brush cutter for rotating an upper blade plate and a lower blade plate in opposite directions, a sun gear, a ring gear and a planetary gear are disclosed in Japanese Utility Model Publication No. 7-28818. Known speed reduction mechanisms are known. In the conventional example disclosed in the above publication, the rotation of the engine is reduced by a worm and a worm wheel, and the target rotation is obtained by a planetary gear reduction mechanism including the sun gear, the ring gear, and the planetary gear. It has become.

[0003]

In the conventional speed reduction mechanism,
Since a large number of gears are used for the speed reduction mechanism including the worm and the worm wheel, the apparatus main body becomes heavy, and there is a disadvantage that it is inconvenient when an operator carries out work by hand. SUMMARY OF THE INVENTION An object of the present invention is to provide a brush cutter that can obtain a desired rotation with a simple speed reduction mechanism, is light in overall weight, and has excellent workability.

[0004]

According to the present invention, in order to solve the above-mentioned problems, the main body case 5 is formed in a plate shape, and gears as a power transmission mechanism are suspended from the plate-shaped main body case 5. . That is, a plurality of support rods 6 and 6 are provided vertically on a circular locus at a fixed distance from the center of the plate-shaped main body case 5, and the lower blade is coaxial with the circular locus below the main body case 5. A sun gear 7 having a plate and a ring gear 8 having an upper blade plate 3 are arranged.

[0005] A plurality of support rods 6 suspended from the body case 5
At least a plurality of support rods of 6 support rolling elements, specifically rollers and small gears 9 circumscribing the sun gear 7 and inscribing the ring gear 8. At least one of the rolling elements is a small gear 9 that meshes with the sun gear 7 and the ring gear 8, and the support rod 6 has a holding unit that prevents the small gear 9, the sun gear 7, and the ring gear 8 from floating in the axial direction. Provide. Thereby, the sun gear 7 and the ring gear 8 can rotate in the opposite directions via the small gear 9. Therefore, by using at least one of the small gears as a drive gear that is rotationally driven by a power source such as an engine or a motor, the rotation of the small gear 9 that is rotationally driven at a high speed is controlled by the sun gear 7.
The upper blade plate 3 and the lower blade plate 4 can be driven to rotate in opposite directions with a large reduction ratio determined by the gear ratio of the small gear 9 and the gear ratio of the ring gear 8 and the small gear 9.

The main body case 5 may be, for example, a disk, but if it has an annular shape having a through hole 5a at the center and the sun gear 7 also has an annular shape having a central hole, that is, an annular external gear, As it is lighter. Further, the small gear 9, the sun gear 7, and the ring gear 8 have a specific structure for preventing the floating movement in the vertical direction. The annular upper support plate 14 and the lower support plate 15 are opposed to the support rod 6 and are fixed through the spacer 16. Hold it at an interval and fix it to the main body case.
An upper roller 18 serving as a spacer is mounted between the lower gear and the upper surface of the small gear 9, and a lower roller serving as a spacer is mounted between the lower support plate 15 and the lower surface of the small gear 9. A guide plate larger than the diameter of the small gear is fixed to the lower surface so that the meshing of the small gear and the sun gear does not come off.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the brush cutter according to the present invention will be described with reference to the accompanying drawings. The brush cutter according to the present invention reduces the rotation of the power source such as the engine 2 mounted on the base end of the handle rod 1 as shown in FIG. A cutting blade provided to the upper blade plate 3 by transmitting the rotation to the lower blade plate 4 in the opposite direction, and holding the handle 1 in a hand.
With the cutting blade 3a and the cutting blade 4a provided on the lower blade plate 4, a mowing operation is performed by a cutting action like scissors.

FIG. 1 is a longitudinal sectional view of only the main part of the brush cutter mounted on the tip of the handle rod 1, and the handle rod is attached to the main part of the brush cutter from obliquely above. In the main body case 5 having an annular shape with a through hole 5a formed in the center thereof, support rods 6 and 6 are provided at a plurality of positions (equal intervals of 12 in the drawing) on a circular locus at a fixed distance from the center O. Hang it down. Below the main body case 5, concentric with the circular locus, a sun gear 7 (annular external gear) having an outer diameter smaller than the circular locus, and a ring gear 8 having an inner diameter larger than the circular locus. (Annular internal gears) are arranged, and at least a plurality of supporting rods 6 rotatably support rolling elements, specifically rollers and small gears 9 circumscribing the sun gear and inscribed with the ring gear, and supporting the sun gear 7 The ring gear 8 smoothly rotates in the opposite direction about the center O as the center of rotation without floating in the plane direction.

Both the main body case 5 and the sun gear 7 may be disk-shaped, but by being formed in an annular shape, a through hole is formed in the center of the body, so that the body can be made lighter. In addition, there is an advantage that the chips generated during the mowing operation can be removed downward from the through holes.

FIG. 3 is a plan view of the gear mechanism. Center O
The supporting rods 6 and 6 are arranged at equal intervals of 12 on a circular locus at a fixed distance from, and small gears 9 and 9 are mounted on every other supporting rod 6, and one of them (on the drawing) The gear located on the right) is the drive gear. Of course, a plurality of small gears may be used as drive gears. Small gears other than the small gear serving as the driving gear are idle gears, and make the rotation of the sun gear 7 and the ring gear 8 smooth. By providing a plurality of, preferably three or more, small gears 9 including those that become drive gears and those that become idle gears, smooth driving can be achieved.

A small gear serving as a drive gear has its central shaft 6A extended upward, a bevel gear 10 attached thereto, and an engine transmitted by power transmission means (shaft, flexible shaft, etc.) of the handle rod 1 of the brush cutter. To the bevel gear 10. In the illustrated example, a small bevel gear rotated at a high speed by an engine or the like meshes with a large bevel gear mounted on the center shaft 6A, so that the first-stage deceleration is performed in the input stage.

When one small gear serving as a driving gear is rotationally driven, the sun gear 7 on which the lower blade plate 4 is mounted and the ring gear 8 on which the upper blade plate 3 is mounted rotate in opposite directions, respectively.
The cutting operation is performed by the cutting blade 3a of the upper blade plate 3 and the cutting blade 4a of the lower blade plate 4. In order to mount the upper blade plate 3 on the ring gear 8, the outer peripheral portion of the ring gear 8 is detachably attached with a mounting pin 11 or the like. On the other hand, in order to mount the lower blade plate 4 on the sun gear 7, a connecting plate 12 extending outward below the small gear 6 is fixed to the lower surface of the sun gear 7 with a bolt or the like. The sun gear 7 is detachably attached to the outer peripheral portion by using a mounting pin 13 or the like.

In the illustrated example, bolts are used as the support rods 6, 6, but a specific example of a structure in which the entire mechanism is vertically provided by the support rods 6 will be described. Below the main body case 5, an annular upper support plate 14 having a substantially U-shaped cross section and an annular lower support plate 15 having a substantially U-shaped cross section are disposed. These main body case 5 and upper support plate
Bolt holes 5b, 14a, and 15a are formed in the lower support plate 14 and the lower support plate 15, respectively. The upper support plate 14 and the lower support plate 15 are fixed to the support rod 6 suspended from the main body case at a predetermined interval by tightening up with the nut 17 with the spacer 16 interposed therebetween. 12 support rods
The gears are arranged at equal positions, one of which is 11 gears for arranging a small gear as a drive gear.

A small gear as an idle gear is placed every other support rod 6 (five support rods in the drawing) on a support rod 6 in which a space between the upper support plate 14 and the lower support plate 15 is held at a fixed interval by a spacer 16. 9 is supported. The support rod that does not support the small gear 9 functions as a structural member that firmly holds the upper support plate 14 and the lower support plate 15 at regular intervals. Small gear 9 mounted on support rod 6
An upper roller 18 is provided between the upper surface of the
A lower roller 19 is disposed between the lower gear plate 9 and the lower gear plate 9.
No gap is formed in the up-down direction so that the small gear 9 does not move.

The specific structure of the small gear 9 is shown in an enlarged manner in FIG. 2, and a disc-shaped upper guide plate 20 having a diameter larger than the outer diameter of the small gear is provided on the upper surface of the small gear 9 and on the lower surface. Lower guide plate 21
Are brought into contact with each other, and are integrated by the central metal shaft 22. Therefore, the sun gear 7 and the ring gear 8 meshing with the small gear 9
Is held on the same plane by the upper guide plate 20 and the lower guide plate 21, and the meshing state with the small gear is maintained. In correspondence with the structure of the small gear, the upper roller 18 for preventing the small gear from floating is formed in a downward cup shape, and the lower roller 19 is formed in an upward cup shape, and an upper guide plate integrated with the small gear.
The contact between the lower gear 20 and the lower guide plate 21 prevents the small gear, and thus the sun gear and the ring gear, from moving in the vertical direction.

An annular seal packing 23 is attached to each of the distal ends of the upper support plate 14 and the lower support plate 15 having a substantially U-shaped cross section. The peripheral seal packing is in close contact with the upper and lower surfaces of the sun gear 7, and the outer peripheral seal packing is in close contact with the upper and lower surfaces of the ring gear 8. Thereby, a meshing space of the sealed small gear 9, sun gear 7, and ring gear 8 is formed, and by filling the meshing space with a lubricant such as grease, smoother driving can be performed. . In the illustrated embodiment, the upper support plate 14 and the lower support plate 15 have a substantially U-shaped cross section, but both the upper support plate 14 and the lower support plate 15 may be planar. In this case, the seal packing for forming the engagement space projects downward in the upper support plate and upward in the lower support plate in a cylindrical shape.

The upper support plate 14 and the lower support plate 15 not only form a meshing space sealed by the seal structure, but also support the sun gear 7 and the ring gear 8 therebetween.
It works synergistically with the upper and lower guide plates of the small gear,
In addition, the ring gear 8 has a function of firmly supporting the ring gear 8 at a meshing position with the small gear. The holding means for preventing the small gear, sun gear and ring gear from floating in the axial direction is provided, for example, with a wide support plate at the tip of the support rod, and this support plate supports the entire small gear, sun gear and ring gear. And the like can be devised.

[0018]

According to the brush cutter according to the first aspect of the present invention,
By rotating the upper blade plate and the lower blade plate in the opposite direction at a low speed, a plurality of cutting blades protruding on the outer peripheral portion of the upper blade plate, and a plurality of cutting blades protruding on the outer peripheral portion of the lower blade plate. A large reduction ratio can be obtained with a simple structure having a small number of gears, with a small gear disposed between a sun gear and a ring gear as an input gear, for a power transmission mechanism of a brush cutter for cutting plants and trees. In addition, since the speed reduction mechanisms are supported by support rods suspended from the plate-shaped main body case, it is possible to achieve a light weight as a whole and excellent workability. Further, in the conventional high-speed rotary brush cutter, there are many troubles such as cutting grass wrapping around the center axis of the rotary blade. However, in the present invention, since there is no center axis, the cutting grass is wrapped. Trouble has improved significantly.

According to the second aspect of the present invention, the main body case and the sun gear can be made lighter, and the brush cutter can be made lighter as a whole. There is an effect of removing chips generated at the time and getting on the surface of the aircraft downward.

According to the third aspect of the present invention, the meshing state of the small gear, sun gear and ring gear constituting the power transmission mechanism can be reliably maintained with a simple structure, and a stable driving state can be maintained. it can.

According to the fourth aspect of the present invention, a closed meshing space is formed by utilizing the structure of the third aspect of the present invention, and a lubricant is filled therein, so that a smoother operation can be achieved. State can be realized. Further, since the rotary drive mechanism can be made completely waterproof, mowing underwater, which is impossible with a conventional high-speed rotary brush cutter, is possible.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of the entire body of a brush cutter,

FIG. 2 is an exploded perspective view of a bush cutter main body,

FIG. 3 is a plan view of a power transmission mechanism of the brush cutter body,

FIG. 4 is a schematic perspective view of the entire brush cutter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Handlebar, 2 ... Engine, 3 ... Upper blade plate, 4 ... Lower blade plate, 3a, 4a ... Cutting blade, 5 ... Body case, 5a ... Through hole,
5b: bolt hole, 6: support rod, 6A: center shaft, 7 ...
Sun gear, 8: Ring gear, 9: Small gear, 10: Bevel gear, 11, 13: Mounting pin, 12: Connecting plate, 14: Upper support plate, 15: Lower support plate, 14a, 15a: Bolt hole, 16
... spacer, 17 ... nut, 18 ... upper roller,
19: Lower roller, 20: Upper guide plate, 21: Lower guide plate, 22: Metal shaft, 23: Seal packing.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A01D 34/63-34/90 F16H 1/30

Claims (4)

(57) [Claims] 1. A plurality of cutting blades protruding from an outer peripheral portion of an upper blade plate by rotating an upper blade plate and a lower blade plate disposed on the same axis at low speed in opposite directions, and a lower blade plate. A plurality of cutting blades protruding from the outer periphery of the bush cutter for cutting plants and trees, wherein the circular shape is provided below a plate-shaped main body case having support rods suspended at a plurality of positions on a circular locus at a fixed distance from the center. On the trajectory and concentrically, a sun gear with a lower blade plate and a ring gear with an upper blade plate are arranged, and the sun gear is circumscribed to at least a plurality of support rods of the support rods suspended at the plurality of positions, Axially supporting a rolling element inscribed in the ring gear, at least one of the rolling elements is a small gear that meshes with the sun gear and the ring gear, and at least one of the small gears is a drive gear that is rotationally driven by a power source, The supporting rods have small gears, sun gears and ring gears A brush cutter comprising a holding means for preventing movement in the direction. 2. The brush cutter according to claim 1, wherein the main body case is an annular external gear having a through hole formed at the center and a sun gear having a through hole formed at the center. 3. The support rod has an annular upper support plate and an annular lower support plate opposed to each other, and the upper support plate and the lower support plate are held at a fixed interval via a spacer. The sun gear and the ring gear meshing with the upper guide plate and the lower guide plate on the lower surface do not move up and down,
An upper roller that acts as a spacer between the upper support plate and the upper surface of the small gear, and a lower roller that acts as a spacer between the lower support plate and the lower surface of the small gear are attached to allow the small gear, sun gear and ring gear to move freely in the axial direction. The brush cutter according to claim 1 or 2, wherein the brush cutter is prevented. 4. A small gear, a sun gear and a ring gear, which are hermetically sealed by attaching seal packings to the inner and outer end edges of the upper support plate and the inner and outer end edges of the lower support plate, respectively, for contacting the surface of a sun gear or a ring gear. The brush cutter according to claim 3, wherein a space is formed, and the meshing space is filled with a lubricant.