JP2004215575A - Bush cutter with braking mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bush cutter with a braking mechanism capable of braking inertial rotation of a cutter after bush cutting at a low cost by extremely simplifying the structure. <P>SOLUTION: This portable bush cutter has a bent member 61 and a transmission wire 62. The bent member 61 has one terminal fixed to a standstill part at the neighbor of a transmission shaft 5 for transmitting a rotary power from a power part 1 to the cutter 3a, and partially surrounds the transmission shaft 5. The transmission wire 62 comes out from a cylindrical part having the tip part fixed to the one terminal of the bent member 61 so as to form a ring with the bent member 61, and to house the transmission shaft 5 so as to be arranged in the inside of the ring, and is connected and fixed with to a brake lever 65 at the rear end part thereof. The bent member is formed out of an elastic body, or a coil spring 63 is inserted to the midway of the transmission wire 62. When the brake lever 65 is grasped, the bent member 61 is brought into contact with the transmission shaft 5 by the transmission wire 62 pulled to the brake lever side. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a brush cutter with a braking mechanism that can stop a cutter that rotates by inertia after cutting weeds or the like by rotating the cutter.
[0002]
[Prior art]
A portable brush cutter called a shoulder-type mower that cuts weeds and the like has been generally used as follows. For example, in a brush cutter having a two-cycle engine, fuel is fed into the engine power unit 1, and when fuel spreads over the engine plug, the accelerator lever 71 is started to start the engine 1 (see FIGS. 1 and 2). . When the engine 1 is started, the accelerator lever 71 is switched from start to operation, and the cutter 3 a is rotated via the transmission shaft 5. The mowing operation is performed while the rotation of the engine 1 is adjusted by the accelerator lever 71 and the rotation of the cutter 3a is adjusted. After the mowing operation is completed, the accelerator lever 71 is returned to stop the cutter 3a.
However, even if the accelerator lever 71 is returned and the engine 1 is stopped, the cutter 3a continues to rotate by inertia and does not stop for a while. It is dangerous that the cutter 3a rotates carelessly even after the work is completed. For this reason, the worker rubs against the ground or grass, etc., but may occasionally be injured if pebbles or the like are repelled and hit a person.
Therefore, as a technique for stopping the rotation of the cutter related to such a brush cutter, several brush cutters having a braking function have been proposed so far. (For example, see Patent Documents 1 and 2.)
[0003]
[Patent Document 1]
JP-A-11-32547 (pages 2-4, FIGS. 2 and 3)
[Patent Document 2]
JP-A-11-220924 (pages 3 to 5, FIGS. 3 and 4)
[0004]
[Problems to be solved by the invention]
However, all of the prior arts have complicated structures and lead to high product costs. Portable mowers have become cheaper to sell, and it has been difficult to reduce the coasting rotation of the cutter after mowing by making it a low-priced product.
[0005]
An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a brush cutter with a braking mechanism capable of extremely simplifying the structure and stopping the coasting rotation of the cutter after mowing is completed at low cost.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the gist of the invention according to claim 1 is a portable brush cutter, wherein one end is fixed to a stationary portion around a transmission shaft that transmits torque from a power unit to a cutter, A curved member (61) that partially surrounds the transmission shaft, a distal end portion is fixed to the other end of the curved member, and the curved member is formed in an arc shape or an annular shape, and the transmission shaft is arranged inside the arc shape or the annular shape. A transmission wire (62) which is pulled out of the cylindrical portion accommodating the transmission shaft and whose rear end is connected and fixed to the brake lever, and wherein the bending member is formed of an elastic body or in the middle of the transmission wire When the brake lever is grasped, the transmission wire is drawn to the brake lever side so that the bending member comes into contact with the transmission shaft and the brake lever is opened. Under the condition, said Songs member or the bending member by an elastic restoring force of the coil spring is in a brush cutter with a braking mechanism, characterized in that apart from the transmission shaft.
[0007]
Like the brush cutter with a braking mechanism according to claim 1, the bending lever (61), the transmission wire (62), the bending member is formed of an elastic body or a coil spring (63) is provided, and the brake lever is gripped. If the bending member is set in contact with the transmission shaft by the transmission wire being pulled toward the brake lever, the coasting rotation of the cutter can be suppressed by frictional resistance due to the contact. On the other hand, if the bending member is separated from the power transmission shaft by the restoring force of the bending member or the coil spring when the brake lever is released, the bending member or the coil spring is restored to its original state without applying an external force.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the brush cutter with a braking mechanism of the present invention will be described in detail.
(1) Embodiment 1
1 to 6 show an embodiment of a brush cutter with a braking mechanism according to the present invention (hereinafter simply referred to as a "cutter cutter"). FIG. 1 is an overall perspective view thereof, and FIG. 2 is a longitudinal section around a cutter in FIG. 3 and 4 are views taken along the line AA of FIG. 2 when the brake lever is released and released, FIG. 4 is a view taken along the line AA of FIG. 2 when the brake lever is operated, and FIG. FIG. 6 is a partial perspective view of FIG.
[0009]
This brush cutter is a portable brush cutter, and includes a well-known power unit 1, an outer tube 2, a brush cutter main body 3, a handle 4, a transmission shaft 5, an accelerator lever 71, and a braking mechanism 6 as a main part of the present invention. (Figs. 1 and 2). The power section 1 is attached to the base end of the rod-shaped outer tube section 2, the brush cutter body 3 is attached to the distal end of the outer tube section 2, and a handle is provided near the power section 1 of the outer tube section 2. 4 is attached to make it easy to perform the mowing operation while walking. The cutter 3a of the brush cutter body 3 rotates via the transmission shaft 5 by the drive from the power unit 1 of the air-cooled two-cycle engine. By holding the accelerator lever 71, the rotation speed of the engine 1 is increased via the accelerator transmission wiring 72, and the rotation speed of the cutter 3a is increased. If the accelerator lever 71 is released from being released, oil supply to the engine 1 is stopped and the cutter 3a coasts for a while.
A transmission shaft main portion 50 related to the transmission shaft 5 accommodated in the outer tube portion 2 transmits the rotation of the engine 1 to a transmission shaft portion 53 related to the transmission shaft 5 via, for example, oblique bevel gears 51, 51. The transmission shaft 53 transmits the rotation from the engine 1 to the cutter 3a attached to the lower end thereof (FIG. 2). The oblique bevel gear 51 can be replaced with a universal joint or the like.
[0010]
Reference numeral 30 denotes a cylindrical housing with a bottom of the brush cutter main body 3, and the bending member 61 and the like of the braking mechanism 6 according to the present invention are housed in the cylindrical portion 30 a of the housing 30.
Reference numeral 83 denotes a bearing for rotatably holding the main portion 50 of the transmission shaft 5, and a stationary portion thereof is fixed to the outer tube portion 2 by a not-shown locking member. Reference numerals 81 and 82 denote bearings for rotatably holding the transmission shaft 53 of the transmission shaft 5, and their stationary portions are fixed to the housing cylinder 30 a by locking members (not shown). Reference numeral 35 denotes a holding plate of the cutter 3a, reference numeral 36 denotes a fixing nut for the holding plate, and reference numeral 39 denotes a cover.
[0011]
The braking mechanism 6, which is a main component of the present invention, is incorporated in the above-mentioned known brush cutter. The braking mechanism 6 includes a bending member 61, a transmission wire 62, a coil spring 63, a projecting piece 641, a stop piece 642, a stopper 67, and a brake lever 65.
The bending member 61 is a metal molded plate formed by bending a strip having a predetermined width into an arc shape. The bending member 61 has one end 611 fixed to a stationary portion around the transmission shaft 53 related to the transmission shaft 5 that transmits the rotational force from the power unit 1 to the cutter 3 a, and is disposed so as to partially surround the transmission shaft 5. (FIGS. 3 and 5). Here, the cylindrical portion 30a is selected as a stationary portion, and one end 611 of the bending member 61 is fixed to the inner wall thereof with screws. The bending member 61 of the present embodiment is made of an elastically deformable steel strip, and is elastically deformed by pulling and bending the other end 612 of the bending member 61.
[0012]
The transmission wire 62 has a distal end 621 fixed to the other end 612 of the bending member 61 and is formed in an annular shape with the bending member 61, and the transmission shaft 5 (here, the transmission shaft portion 53) is disposed in the annular shape. This is a transmission means which comes out of the cylindrical portion 30 a that houses the transmission shaft 5 and whose rear end is connected and fixed to the brake lever 65. The transmission wire 62 may be configured such that the distal end portion 621 is fixed to the other end 612 of the bending member 61 and is formed in an arc shape with the bending member 61, and the transmission shaft 5 is arranged inside the arc shape. This is because the same operation and effect as those of the present invention can be obtained. The brake lever 65 is attached to the other end of the handle opposite to the one end of the handle 4 to which the accelerator lever 71 is attached. The transmission wire 62 is housed in the covering tube 62a except for both ends.
[0013]
A protruding piece 641 is erected and fixed to the inner wall of the cylindrical portion 30a near the other end 612 of the bending member 61, and a stop piece 642 is formed at a predetermined interval from the protruding piece 641 so as to face the same. It is erected and fixed to the outer wall of 30a (FIGS. 3 and 5). After inserting the distal end of the transmission wire 62 into the small hole 642a provided in the stop piece 642, the coil spring 63 is inserted and the transmission wire 62 is further inserted into the small hole 641a provided in the protruding piece 641. 621 is fixed to the other end 612 of the bending member 61. The transmission wire 62 having the distal end portion 621 fixed to the bending member 61 in the cylindrical portion 30a passes through the stop piece 642 so that the transmission wire 62 is substantially tangent to a substantially annular circle formed by the bending member 61. The rear end is connected to the brake lever 65 provided at the handle end by connecting the outer tube 2 to the outside of the tube 30a (FIGS. 1 and 3). A stopper 67 is attached to the tip of the coil spring 63 on the side of the projecting piece 641, and the stopper 67 is fixed to the transmission wire 62 so that the coil spring 63 is sandwiched between the stopper 67 and the stopper 642.
[0014]
When the brake lever 65 is grasped, the bending member 61 is bent by the transmission wire 62 being drawn toward the brake lever 65, so that the bending member 61 comes into contact with the transmission shaft 5 so that the inertial rotation of the transmission shaft 5 can be suppressed. At the same time, when the brake lever 65 is released and released, the bending member 61 is separated from the transmission shaft 5 by the restoring force of the bending member 61 or the coil spring 63. When the brake lever 65 is grasped, the transmission wire 62 is pulled toward the brake lever 65, and the stopper 67 moves toward the stop piece 642. As a result, the radius of curvature of the bending member 61 decreases, and the bending member 61 comes into contact with the transmission shaft 5 (FIGS. 4 and 6). A frictional resistance is generated by the contact of the bending member 61 with the transmission shaft 5, and the rotation of the cutter 3a is braked. In the present embodiment, the diameter of the transmission shaft portion 53 of the transmission shaft 5 is increased so that the enlarged diameter portion 52 is formed so that the bending member 61 easily contacts the transmission shaft 5 with a slight deformation (FIG. 2). When the bending member 61 comes into contact with the enlarged diameter portion 52, the frictional resistance of the bending member 61 can suppress the inertial rotation of the transmission shaft 5.
When the stopper 67 moves toward the stop piece 642, the coil spring 63 is compressed by the stopper 67 fixed to the transmission wire 62 and the stop piece 642. Therefore, when the brake lever 65 is released, the stopper 67 is pushed back to the protruding piece 641 side by the elastic restoring force of the coil spring 63, and the bending member 61 returns to the initial state in which the bending member 61 is separated from the transmission shaft 5. Further, as described above, the bending member 61 can be elastically deformed. When the brake lever 65 is released, a restoring force accompanying the elastic deformation of the bending member 61 is applied, and the bending member 61 is promoted to separate from the enlarged diameter portion 52. I do. When the bending member 61 can be returned to the initial state by the elastic deformation force, the coil spring 63 can be omitted.
In the figure, the illustration of the shoulder hook is omitted.
[0015]
The brush cutter with the braking mechanism configured as described above can stop the cutter 3a that rotates by inertia after the accelerator lever 71 is loosened and the engine is stopped, with a very simple configuration. After the mowing operation is completed, the cutter 3a, which still coasts even when the accelerator lever 71 is released, can be easily stopped by frictional contact of the bending member 61 of the braking mechanism 6. After finishing the work, the brush cutter also having such a braking mechanism 6 does not require the operator to rub against the ground or grass as in the related art. Anxiety such as injury due to the cutter 3a rotating by inertia can be eliminated, and the brush cutter can be improved at low cost and with improved safety.
[0016]
(2) Embodiment 2
In this embodiment, as shown in FIGS. 7 to 9, instead of installing the bending member 61, the coil spring 63, and the like according to the braking mechanism 6 in the housing cylinder 30a of the first embodiment, the housing is provided inside the cylinder 2 of the outer tube. This is a brush cutter with a braking mechanism in which a bending member 61, a coil spring 63, and the like according to the braking mechanism 6 are installed. 7 is a partially cutaway perspective view of the brush cutter, FIG. 8 is a partial perspective view around the bending member when the brake lever is opened, and FIG. 9 is a partial perspective view around the bending member when the brake lever is grasped.
[0017]
A part of the outer tube portion 2 between the handle 4 and the engine 1 is cut out as shown in FIG. 7, and a protruding piece 641 is erected toward the inside of the tube portion 2 at the cutout cutout edge. A stop piece 642 is fixed to the outer wall side of the cylindrical portion 5 so as to face the protrusion 641 at a predetermined interval from the protrusion 641. An elastically deformable bending member 61 is fixed at one end to a stationary portion (in this case, the inner wall of the cylindrical portion 2) around the transmission shaft 5 (specifically, the main portion 50) and partially surrounds the transmission shaft 5. You.
[0018]
Further, as in the first embodiment, the distal end 621 of the transmission wire 62 is fixed to the other end 612 of the bending member 61 (not shown). The transmission wire 62 having the distal end 621 fixed to the bending member 61 in the cylindrical portion 30a is inserted into the small hole 641a provided in the protruding piece 641 and then the coil spring 63 is inserted thereinto. It is inserted and comes out of the cylindrical portion 5 (FIGS. 8 and 9). The transmission wire 62 comes out of the cylindrical portion 30a so as to be substantially tangent to a substantially annular circle formed by the bending member 61. The transmission wire 62 that has come out of the outer tube portion 25 connects the outer tube portion 2 and connects the rear end of the transmission wire to a brake lever 65 provided at the handle end. As in the first embodiment, a stopper 67 is attached to the tip of the coil spring 63 on the protruding piece 641 side, and the stopper 67 is fixed to the transmission wire 62 so that the coil spring 63 is sandwiched between the stopper 67 and the stop piece 642. .
[0019]
Thus, when the brake lever 65 is gripped, the transmission wire is drawn toward the brake lever, so that the bending member 61 comes into contact with the transmission shaft 5 so as to stop the inertial rotation of the transmission shaft 5 (FIG. 9). ). On the other hand, when the brake lever 65 is released, the bending member 61 is separated from the main portion 50 of the transmission shaft 5 by the restoring force of the bending member 61 or the coil spring 63 (FIG. 8).
Other configurations are the same as in the first embodiment, and a description thereof will be omitted. The same reference numerals as those in the first embodiment denote the same or corresponding parts.
[0020]
The brush cutter with the braking mechanism configured as described above can obtain the same operation and effect as the first embodiment. In the present embodiment, the distance between the bending member 61 and the brake lever 65 on which the braking action is performed is shorter, and the number of failures is smaller than in the first embodiment, so that the operability is excellent and the transmission wire 62 is shortened. Will also be connected and become even better.
[0021]
It should be noted that the present invention is not limited to the embodiment described above, and various changes can be made within the scope of the present invention depending on the purpose and application. The shape, size, number, material, and the like of the power unit 1, outer tube cylinder unit 2, brush cutter body 3, handle 4, transmission shaft 5, braking mechanism 6, accelerator lever 71, etc. can be appropriately selected according to the application.
[0022]
【The invention's effect】
As described above, the brush cutter with the braking mechanism of the present invention can stop the coasting rotation of the cutter after the completion of mowing while extremely simplifying the structure, and has an excellent effect as a contribution to product safety and low cost. Demonstrate.
[Brief description of the drawings]
FIG. 1 is an overall perspective view of a brush cutter with a braking mechanism according to a first embodiment.
FIG. 2 is a longitudinal sectional view around the cutter of FIG. 1;
FIG. 3 is a view taken along the line AA of FIG. 2 when the brake lever is released and released.
FIG. 4 is a view on arrow AA of FIG. 2 when a brake lever is operated.
FIG. 5 is a partial perspective view of FIG. 3;
FIG. 6 is a partial perspective view of FIG.
FIG. 7 is a partially cutaway perspective view of a brush cutter with a braking mechanism according to a second embodiment.
FIG. 8 is a partial perspective view around the bending member when the brake lever is released.
FIG. 9 is a partial perspective view around the bending member when the brake lever is depressed.
[Explanation of symbols]
1 power unit (engine)
2 tube part (outer tube tube part)
3a cutter 30a cylindrical portion 5 transmission shaft 50 transmission shaft (main portion)
53 Transmission shaft (transmission shaft)
61 Bending member 611 One end 612 Other end 62 Transmission wire 621 Tip 63 Coil spring 65 Brake lever

Claims (1)

In a portable brush cutter,
A curved member (61) having one end fixed to a stationary portion around a transmission shaft that transmits the rotational force from the power unit to the cutter, and partially surrounding the transmission shaft;
The distal end portion is fixed to the other end of the bending member and is formed in an arc shape or an annular shape with the bending member, and the transmission shaft is disposed inside the arc shape or the annular portion so that the transmission shaft is housed outside, and the cylinder is housed outside. A transmission wire (62) having a rear end connected and fixed to the brake lever;
A coil spring (63), wherein the bending member is formed of an elastic body or is inserted in the middle of the transmission wire;
When the brake lever is depressed, the transmission wire is pulled toward the brake lever, so that the bending member comes into contact with the transmission shaft. On the other hand, when the brake lever is open, the elastic restoring force of the bending member or the coil spring is obtained. And the bending member moves away from the transmission shaft.

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