JP3157476B2 - Handle support structure of 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 a brush cutter used for mowing and the like, and more particularly to a brush cutter in which the operating rod is made of FRP (Fiber Reinforced Plastics) in order to reduce the weight. An object of the present invention is to provide a handle support structure of a brush cutter that can effectively prevent breakage at a support portion.

[0002]

2. Description of the Related Art Conventionally, mowers have been widely used for efficient mowing. Conventionally known brush cutters have various configurations in their details, but are basically configured as shown in FIG. That is, a hollow cylindrical operating rod 1 made of a metal material such as an aluminum alloy, a cutting blade 2 rotatably provided at one end (lower right end in FIG. 10) of the operating rod 1, and an operating rod 1 And a prime mover 3 provided at the other end (upper left end of FIG. 10). Further, a transmission shaft, which is rotatably supported by at least one bearing portion and allows the power of the motor 3 to be transmitted to the cutting blade 2, is inserted through the inside of the operation rod 1. Further, an operation handle 5 is fixed to an intermediate portion of the operation rod 1 by a mounting bracket 4 so that an operator can grip the operation handle 5 to operate the operation rod 1 freely. The prime mover 3 is provided with a recoil starter 7 having a starter knob 6, and the prime mover 3 is started by operating (pulling) the starter knob 6.

[0003] When performing a work such as mowing by using the above-described brush cutter, the worker attaches the brush cutter to the body by the belt 8 and the recoil starter 7 provided on the motor 3 as shown in FIG. By pulling the starter knob 6, the motor 3 is started. Thereby, the driving force of the prime mover 3 is transmitted to the cutting blade 2 via the transmission shaft, and the cutting blade 2 rotates. In this state, the operator performs the mowing operation while gripping the operation handle 5 and swinging (rotating) the operating rod 1 right and left (in the direction of arrow A in FIG. 10).

By the way, in order to reduce the weight of the conventional brush cutter as described above, the operating rod 1 is connected to an FRP (Fiber Reinfo).
rced Plastics).
It is actually used. The above FRP is the CFR
P (Carbon Fiber Reinforced Plastics) and GFRP
(Glass Fiber Reinforced Plastics). By making the operating rod 1 made of FRP, the weight of the brush cutter as a whole can be reduced, and the burden on the operator can be reduced.

[0005]

However, when the operating rod 1 is made of FRP as described above, stress is applied to the operating rod 1 during the mowing operation, for example, when the cutting blade 2 comes into contact with or comes into contact with a small tree. At this time, there is a possibility that the operating rod 1 may be cracked or, in a severe case, may be broken.
It is higher than the case where the operating rod 1 is made of an aluminum alloy. This is because the elasticity of the FRP is smaller than that of the aluminum alloy. Such cracks and breakage are remarkable in the handle support portion where it is difficult to disperse the stress. That is, since the handle 5 is fixed by the mounting bracket 4 in the handle support portion, it is difficult to smoothly support the stress. For this reason, the crack or breakage is more likely to occur in the handle support portion than in other portions.

In order to prevent the above-mentioned accident, it is conceivable to provide a structure for smoothly supporting (releasing) the stress on the handle support portion.
There is no known brush cutter provided with such a structure.
Japanese Utility Model Publication No. 59-42530 discloses a structure in which a vibration isolator is provided at a handle support portion. The structure described in this publication is conceived for the purpose of preventing vibration during work, and it is difficult to smoothly support the stress. That is, in the case of the structure described in the above publication, the vibration isolator is provided on the handle supporting portion of the operating rod made of aluminum alloy. If the operating rod is made of an aluminum alloy as described above, it is conceivable that the above-mentioned stress may be relieved to some extent by the action of the elastic aluminum operating rod and the vibration isolator, but the operating rod is made of FRP. In such a case, it is difficult to prevent the above-mentioned accident such as breakage due to poor elasticity of the FRP.

It is conceivable to interpose a spacer inside the mounting bracket 4 to receive the above-mentioned stress.
Simply forming the spacer in a cylindrical shape makes it difficult to prevent stress concentration at the handle support portion, so that a significant effect cannot be obtained.

[0008] The handle support structure of the brush cutter of the present invention is conceived in view of the above-mentioned circumstances. When the operating rod is made of FRP, the handle supporting portion of the operating rod may be cracked or broken. It is intended to provide a structure capable of effectively preventing the operation from being performed.

[0009]

The handle support structure of the brush cutter according to the present invention has a hollow cylindrical operating rod made of FRP and a cutting rod rotatably provided at one end of the operating rod. The present invention relates to a handle support structure for a bush cutter including a blade, a power source provided at the other end of the operating rod for rotating and driving the cutting blade, and a handle provided on the operating rod via a fixture.

In particular, in the handle support structure of the brush cutter according to the first aspect, the fixing tool is constituted by upper and lower split members, and a synthetic resin spacer is interposed inside these split members. Furthermore, this spacer is constituted by combining at least two spacer pieces. The spacer has a hollow cylindrical shape and has extending portions extending in the front-rear direction of the operating rod beyond the holding portion of the split member, and the inner diameters of these extending portions increase in diameter toward the opening end. It is formed in a tapered shape.

Further, in the handle support structure of the brush cutter according to the second aspect, similarly to the configuration according to the first aspect, the fixing tool is constituted by upper and lower halves, and is provided inside the two halves. A spacer made of synthetic resin is interposed. Furthermore, this spacer is constituted by combining at least two spacer pieces. The spacer has a hollow cylindrical shape and has extending portions extending in the front-rear direction of the operating rod beyond the holding portion of the split member, and the outer diameters of these extending portions decrease in diameter toward the opening end. It is formed in a tapered shape.

[0012] In the handle support structure of the brush cutter according to the present invention configured as described above, since the bending deformation of the operating rod can be smoothly supported, cracks and breaks are less likely to occur in the handle support portion.

Further, as described in claim 3, a recessed portion into which the split member can be fitted can be formed in the central portion of the spacer described in claim 1 or 2. With this configuration, the work of assembling the split member can be easily performed,
Prevention of breakage and simplification of production can be achieved.

[0014]

Next, embodiments of the present invention will be described with reference to the drawings. 1 to 6 show a first example of an embodiment of the present invention. The brush cutter according to the present embodiment includes an operating rod 1 made of FRP and formed in a hollow cylindrical shape, and a cutting blade 2 rotatably provided at one end of the operating rod 1 (see FIG. 10; omitted from FIGS. 1 to 6). ), And a prime mover 3 (see FIG. 10, omitted from FIGS. 1 to 6) also provided at the other end of the operating rod 1. The prime mover 3 is a power source described in the claims. Further, a transmission shaft (not shown) rotatably supported by at least one bearing portion (not shown) inside the operation rod 1 and capable of transmitting the power of the motor 3 to the cutting blade 2 is provided. It is inserted. An operation handle 5 is fixed to an intermediate portion of the operation rod 1 by a mounting bracket 4 as a fixing tool.
To make the operating rod 1 freely operable. Motor 3 above
Is provided with a recoil starter 7 having a starter knob 6, and the starter knob 6 is operated (pulled).
Thus, the prime mover 3 is started.

In particular, in the handle support structure of the brush cutter of this embodiment, as shown in FIGS.
Is constituted by upper and lower split members 9 and 10.
The split member 9 includes a tubular portion 11 that can be fitted to the center of the handle 5 and a holding portion 12 formed below the tubular portion 11 and having a semicircular cross section. Further, another split member 10 includes a holding portion 13 having a semicircular cross section. Furthermore,
Screw holes 14, 14 are provided at two positions of the holding portion 12,
Bolt insertion holes 15, 15 are provided at two positions of the holding portion 13.
Are formed respectively. These split members 9, 1
Reference numeral 0 denotes a holding portion 12 at an intermediate portion of the operating rod 1,
13 in contact with the inner surface of each bolt insertion hole 15,
The bolts 16 inserted into the screw holes 14
4 and fixed to the operating rod 1 by tightening. Therefore, when the pair of split members 9 and 10 are combined, the holding portions 12 and 13 are formed so that through holes having the same diameter and the same shape as the outer diameter and the outer peripheral shape of the operating rod 1 are formed. 1 and 2, reference numeral 17 denotes a hole for embedding elastic members (for example, rubber members) 18 for vibration damping.

Further, a spacer 19 made of a synthetic resin as shown in FIG. 6 is interposed inside the split members 9 and 10. This spacer 19 is composed of two spacer pieces 2
It is configured by combining 0 and 20. The spacer 19 has a hollow cylindrical shape, and is located between the holding portions 12 and 13 of the split members 9 and 10 in the front-rear direction of the operating rod 1 (substantially the left-right direction in FIG. 1, the vertical direction in FIGS. 5
(Extending portions 21, 21) extending in the front-to-back direction. The inner diameter of each of the extending portions 21 is formed in a tapered shape whose diameter increases toward the opening end. Therefore, these extending portions 21 and 21 become thicker toward the axial center of the spacer 19.

As a result, in the handle support structure of the bush cutter of this embodiment, even if stress is applied to the operating rod 1 during the bushing operation, for example, when the cutting blade 2 comes into contact with or comes into contact with the small tree, this stress is smoothly removed. Operating rod 1
Can be effectively prevented from being cracked or an accident such as breakage of the portion. The synthetic resin forming the spacer 19 is Duracon, polyamide,
Polypropylene, polyethylene and the like can be adopted. In particular,
Polyethylene can be preferably used from the viewpoint of price and properties such as elasticity.

Further, in the case of this embodiment, as shown in FIG. 6, a recess 22 is formed in the center of the spacer 19 so that the halves 9 and 10 can be fitted therein. For this reason, the work of assembling the split members 9 and 10 to the operating rod 1 can be easily performed. Although such a concave portion 22 does not contribute to the prevention of the breakage, it facilitates the assembling work and contributes to a reduction in the manufacturing cost. The effect increases.

Next, FIGS. 7 to 9 show a second embodiment of the present invention. Note that the structure of this embodiment is the same as that of the first embodiment described above.
Only the shape of the spacer 19a is different from the structure of the example. Therefore, description of the same parts as those of the first example is omitted, and the spacer 19a will be described in detail below. The spacer 19a in this example is composed of two spacer pieces 20a, 2a made of the above-described various synthetic resins.
0a. The spacer 19a has a hollow cylindrical shape and has extending portions 21a, 21a extending in the front-rear direction of the operating rod 1 beyond the holding portions 12, 13 of the split members 9, 10, and these extending portions 21a , 21a are formed in a tapered shape having a smaller diameter toward the opening end. Further, a concave portion 22a into which the halving members 9 and 10 can be freely fitted is formed in a central portion of the spacer 19a. With such a configuration, the extending portions 21a, 21a are provided with the spacers 19a.
Becomes thicker toward the axial center.

As a result, in the handle support structure of the brush cutter of this embodiment, even when stress is applied to the operating rod 1 during the brush cutting operation, for example, when the cutting blade 2 comes into contact with or comes into contact with the small tree, this stress is smoothly removed. Operating rod 1
It is possible to effectively prevent an accident such as a crack or breakage from occurring. Further, due to the presence of the concave portion 22a, the work of assembling the split members 9, 10 can be easily performed, which contributes to a reduction in manufacturing cost.
For this reason, a brush cutter excellent in durability can be provided at low cost, and the practical effect is increased.

In each of the above examples, the spacer 1
Although an example is described in which the spacers 9 and 19a are divided into two parts, the spacers 19 and 19a may be formed of more spacer pieces 20 and 20a, such as three parts. Furthermore, although the claims in this specification are given reference numerals in order to facilitate correspondence with the drawings, the present invention is not limited thereto.

[0022]

The handle support structure of the brush cutter according to the present invention has the following features.
Since the structure and operation described above are performed, the weight of the brush cutter as a whole can be reduced, accidents such as breakage of the handle support portion can be effectively prevented, and durability can be improved.

[Brief description of the drawings]

FIG. 1 is an essential part exploded perspective view showing a structure of a first example of an embodiment of the present invention.

FIG. 2 is a plan view of an essential part of the same.

FIG. 3 is a front view of the same main part.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a sectional view taken along line BB of FIG. 2;

FIG. 6 shows a spacer piece, (A) is a plan view,
(B) is a front view, (C) is a bottom view, and (D) is a longitudinal sectional view.

FIG. 7 is a sectional view similar to FIG. 4, showing a structure of a second example of the embodiment of the present invention;

FIG. 8 is a sectional view similar to FIG. 5;

FIG. 9 shows a spacer piece, (A) is a plan view,
(B) is a front view, and (C) is a longitudinal sectional view.

FIG. 10 is a perspective view showing a conventionally known brush cutter in a used state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Operating rod 2 Cutting blade 3 Motor 4 Mounting bracket 9, 10 Split member 12, 13 Nipping part 19, 19a Spacer 20, 20a Spacer piece 21, 21a Extension part 22, 22a Recess

Claims (3)

(57) [Claims] An operating rod (1) made of FRP and formed in a hollow cylindrical shape, a cutting blade (2) rotatably provided at one end of the operating rod (1), and the cutting blade (2). Equipped with a power source (3) provided at the other end of the operating rod (1) to rotationally drive the steering wheel, and a handle (5) provided via a fixture (4) on the operating rod (1). It is a handle support structure of a dispenser, wherein the fixing tool (4) includes upper and lower split members (9) (1).
0) and a spacer (1) made of a synthetic resin is provided inside the split members (9) and (10).
9), and the spacer (19) is constituted by combining at least two spacer pieces (20) and (20), and the spacer (19) is a hollow cylindrical member and the split member (20). 9) An extension part (21) extending in the front-rear direction of the operating rod (1) beyond the holding parts (12) and (13) of (10).
(21) The handle support structure of the brush cutter, wherein the inner diameters of the extending portions (21) and (21) are formed in a tapered shape having a larger diameter toward the opening end. 2. An operating rod (1) made of FRP and formed in a hollow cylindrical shape, a cutting blade (2) rotatably provided at one end of the operating rod (1), and the cutting blade (2). Equipped with a power source (3) provided at the other end of the operating rod (1) to rotationally drive the steering wheel, and a handle (5) provided via a fixture (4) on the operating rod (1). It is a handle support structure of a dispenser, wherein the fixing tool (4) includes upper and lower split members (9) (1).
0), and a spacer (19) made of a synthetic resin is provided inside the split members (9) and (10).
a) is interposed, and the spacer (19a) is constituted by combining at least two spacer pieces (20a) (20a), and the spacer (19a) is a hollow cylindrical member and the split member (20). 9) (10) clamping portion (12) (1)
3) extending portions (21a) and (21a) extending in the front-rear direction of the operating rod (1), and these extending portions (21a).
A handle support structure for a brush cutter, wherein the outer diameter of (21a) is formed in a tapered shape having a smaller diameter toward the opening end. 3. A concave part (22) (22a), into which the split members (9) (10) can be fitted, is formed in the center of the spacer (19) (19a). 3. The handle support structure of the brush cutter according to 2.