JPH08140452A - Rotary cutting blade apparatus of brush clearer - Google Patents

Abstract

PURPOSE: To provide a rotary cutting blade apparatus capable of improving the utilization efficiency of an elastic cutting cord as a cutting blade without using an expensive special elastic cutting cord. CONSTITUTION: This cutting blade apparatus is provided with a rotary disk 1 driven and rotated integrally with the rotary shaft of a bush clearer, an insertion hole 5 opened near the outer circumferential part of the disk 1, having wide width at the inner side of the disk and narrow width at the outer circumferential part and holding an elastic cutting cord 7 inserted into the hole and an elastic cord holding member 6 placed in the broad width region of the insertion hole 5. An elastic cutting cord is inserted into the insertion hole 5 from the outer circumferential side and supported in foldable state. The elastic cutting cord is held by projecting an end of the folded cord from the outer circumferential face.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary cutting blade device of a brush cutter that is rotatably attached to a brush cutter and brushes weeds and the like by a rotating elastic blade code.

[0002]

2. Description of the Related Art Conventionally, with respect to a rotary plate body such as a disk which is detachably fixed to a rotary shaft, an elastic cord for mowing of a certain length is projected around the rotary plate body as a cutting blade, and Various techniques have been proposed for a brush cutter for brushing weeds by rotating the elastic blade code together with the disk by rotation.

The elastic cutting blade cord is formed by using a relatively hard synthetic resin cord or a spring wire, and the disc is subjected to a strong centrifugal force so as to face the outer periphery of the disc. It is attached so that it will not come off easily even in cases such as.

As a mounting structure for this elastic cord, for example, in Japanese Utility Model Publication No. 2-9626, an elastic cutting blade cord is inserted from the outer peripheral side into a radial mounting hole between a disc and an annular plate forming a disc, It has been proposed that the inner peripheral side of the annular plate is pulled out to the outer peripheral side from another adjacent mounting hole, and at this time, the mounting base portion of the elastic cord is held by the pressing inclined surface.

Further, in Japanese Utility Model Laid-Open No. 61-22444, the tip of a folded bent portion of an elastic cutting blade cord inserted into a radial mounting hole similar to the above, which is folded back inside the disc, is inserted into a through hole of an annular plate. A device that is inserted and locked is proposed.

Further, in Japanese Utility Model Laid-Open No. 64-38912, a relatively large locking member attached to the base end of a fixed-length elastic cutting blade cord is provided in a slot formed in a rotary plate. It is proposed that they are fitted so as not to be removed.

[0007]

However, Japanese Utility Model Publication No. 2-9626 and Japanese Utility Model Publication No. 61-22444.
In the elastic cutting blade cord mounting structure shown in Japanese Patent Publication, since the curvature of the bent portion of the elastic cutting blade cord is relatively large, the elastic cord will be released from the radial mounting holes or through holes when a large tensile force is applied. In addition to the relatively easy removal, the elastic cutting blade cord requires a considerable length for mounting and holding as described above, which causes a problem that the utilization efficiency as the original cutting blade is significantly deteriorated.

Further, in the elastic cutting blade cord mounting structure disclosed in Japanese Utility Model Laid-Open No. 64-38912, it is necessary to fix the locking member to the proximal end of the elastic cutting blade cord by caulking or the like. It is necessary to use expensive standard length nylon cords specially created for cutting blades.
There was a problem that replacement of the elastic cutting blade cord was troublesome due to its structure. The invention of claim 1 has been made to solve the above-mentioned problems, and does not use an expensive and special elastic cord, and improves the utilization efficiency of the elastic cutting blade cord as a cutting blade. It is an object of the present invention to obtain a rotary cutting blade device for a brush cutter, which is easy to construct and easy to handle, at low cost.

A second aspect of the present invention is to provide a rotary cutting blade device for a brush cutter capable of easily and securely fixing an elastic cutting blade cord having a predetermined outer diameter with a short locking length. To do.

Further, according to the invention of claim 3, it is possible to obtain a rotary cutting blade device of a brush cutter capable of easily and reliably fixing elastic cutting blade cords having different outer diameter dimensions to a rotary plate body with a short locking length. To aim.

[0011]

According to a first aspect of the present invention, there is provided a rotary cutting blade device for a brush cutter, which comprises: a rotary plate body which is driven to rotate integrally with a rotary shaft of the brush cutter; The inner peripheral side of the plate body is wide and the outer peripheral side is provided with an insertion hole for the elastic cutting blade cord having a narrow width, and the elastic cord holding member provided in the wide region of the insertion hole, The elastic cutting blade cord inserted from the outer peripheral side of the narrow area portion of the insertion hole is supported so as to be capable of being folded back, and the folded back elastic cutting blade cord end portion is led out and held to the outer peripheral side. It is a thing.

In the rotary cutting blade device for a brush cutter according to a second aspect of the present invention, the elastic cutting blade cord holding member is a cylindrical member fixed in the wide region of the insertion hole.

In the rotary cutting blade device for a brush cutter according to a third aspect of the present invention, the elastic cutting blade cutting blade cord holding member is provided so as to be movable at least in a radial direction of the plate body within a certain range. It is a spherical member or a cylindrical member.

[0014]

According to the rotary cutting blade device of the brush cutter of the present invention, an elastic cutting blade cord is inserted into the insertion hole from the outer peripheral side of the rotary plate body, and the elastic cutting blade cord is located in the wide area portion. After being wrapped around the back surface of the cord holding member and folded back, the elastic cutting blade cord is pulled back into the insertion hole and led out to the outer peripheral side, so that the elastic cutting blade cord is at least in the narrow region portion near the inlet portion of the insertion hole. , Sufficiently frictionally contact each other and also sufficiently frictionally contact the inner surface of the insertion hole.

As a result, the elastic cutting blade cord is bent along the elastic cutting blade cord holding member with a very small curvature, and the tip end thereof is strongly pressed in the narrow region, so that the rotary plate body is pressed. Even if the elastic cutting blade cord is pulled outward, it maintains a sufficiently strong holding force and is not pulled out from the insertion hole.

Further, in the rotary cutting blade device of the brush cutter according to the invention of claim 2, the elastic cutting blade cord holding member is a fixed columnar member, and therefore has a predetermined outer diameter dimension. The tip portion of the elastic cutting blade cord can be clamped and held in the insertion hole.

Further, in the rotary cutting blade device of the brush cutter according to the invention of claim 3, the elastic cutting blade cord holding member has a cylindrical shape or a spherical shape, and moves in the radial direction of the rotary plate body in the insertion hole. Since it is possible, various types of elastic cutting blade cords having a relatively wide range of outer diameter dimensions can be inserted and held.

In particular, when the elastic cutting blade cord is pulled to the outside of the rotary plate, the elastic cutting blade cord holding member moves to the narrow region side of the insertion hole and bites into the elastic cutting blade cord side. At the same time, this is pressed against the inner surface of the insertion hole more strongly. This reliably prevents the elastic cutting blade cord from being pulled out.

Further, the insertion of the elastic cutting blade cord into the insertion hole is further facilitated by the elastic cutting blade cord holding member escaping in the insertion (inner peripheral) direction of the elastic cutting blade cord within the wide area thereof. It

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are a plan view and a cross-sectional view specifically showing an example of the rotary brush cutter, in which FIG.
Is a disc-shaped rotary plate made of steel plate having a plate thickness of about 1.2 mm, and at the center of the disc-shaped rotary plate body, so that it can be used in the same manner as a disc blade used in a brush cutter with a known structure, A center hole 2 is provided which is inserted through the rotary drive shaft of the dispenser and which is detachably fixed.

A ring-shaped reinforcing rib portion 3 is formed in the middle of the disc 1 in the radial direction.

Further, 4 is an annular plate joined and fixed to one surface near the outer peripheral portion of the disc 1 by spot welding or the like. The annular plate 4 is elastically cut with nylon monofilament or the like by drawing. A pair of bulges 8 are formed in the diametrical direction to form a through hole 5 for holding the blade cord with one surface of the disc 1.

These bulging portions 8 are formed at a height at which an elastic cord having a predetermined outer diameter dimension can be inserted, and the insertion holes 5 formed by the bulging portions 8 are formed on the inner and outer peripheral sides of the annular plate 4. It has a predetermined shape and size that penetrates it. Then, as shown in FIG. 3, the insertion hole 5 is wide on the inner peripheral side of the annular plate 4 and narrow on the outer peripheral side,
A wide area portion 5a and a narrow area portion 5b are formed, respectively.

Further, a steel columnar member 6 as an elastic cutting blade cord holding member is provided in the wide area 5a in the insertion hole 5 and is welded between the disc 1 and the annular plate 4 by welding. It is fixed. The narrow region portion 5b
Has a size such that two elastic cutting blade cords each having a predetermined outer diameter can be lightly inserted at the same time by press fitting.

FIGS. 4 and 5 are an end view and a sectional view specifically showing the vicinity of the opening end on the outer peripheral side of the narrow region portion 5b and the central portion of the wide region portion 5a.

Next, a case where the elastic cutting blade cord 7 is held by the rotary cutting blade device having the above construction will be described. First, the elastic cutting blade cord 7 cut into a predetermined length (for example, 10 cm) that is most suitable for brush cutting is prepared, and this is inserted into the insertion hole 5
The elastic cutting blade cord 7 is inserted deeply into the insertion hole 5 from the outer peripheral side of the elastic cutting blade cord 5b.

By this pushing, the elastic cutting blade cord 7 is projected from the right side (or left side) of the cylindrical member 6 to the inner peripheral side of the annular plate 4 in FIG. The tip portion 7a of the elastic cutting blade cord 7 is folded back against the elastic force so as to bypass the back surface.

Further, following this folding back, in FIG. 3, the columnar member 6 is pulled out from the left side (or right side) to the outer peripheral side of the insertion hole 5 through the narrow region 5b. And
When the pull-out length reaches a predetermined portion on the outer peripheral side, which is shown in the drawing, a portion protruding from the outer peripheral side of the elastic cutting blade cord 7,
That is, the cutting blade side is pulled. As a result, the state shown in FIG. 3 is obtained.

That is, the elastic cutting blade cord 7 makes frictional contact with each other while being biased in opposite directions on the insertion side and the withdrawal side, and also makes frictional contact with the disc 1 and the annular plate 4 in the narrow region 5b. By bending with a small curvature by the cylindrical member 6, the elastic cutting blade cord 7 is completely prevented from being pulled out even if it is strongly pulled by centrifugal force or the like during work.

In this embodiment, since the columnar member 6 is of a fixed type, in order to be able to hold the elastic cutting blade cord 7 sufficiently, the elastic cutting blade cord 5 itself is elastically cut in relation to the narrow region portion 5b. Since the outer diameter of the blade cord 7 has a certain limit, it becomes difficult to hold a remarkably thin elastic cord.

6 and 8 show the elastic cutting blade cord 7
FIG. 7 is a cross-sectional view showing a portion bypassing the cylindrical member 6, and FIG. 7 is an end view showing an outer peripheral side open end of the narrow region portion 5b in a state where the elastic cutting blade cord 7 is held.

Further, although the columnar member 6 is used as the elastic cutting blade cord holding member in this embodiment, an elliptical or other shape may be used.

The elastic cutting blade cord 7 can be held more reliably by roughening the surface of the elastic cutting blade cord holding member to form a friction surface.

9 to 15 show another embodiment of the present invention. This embodiment is different from the embodiment shown in FIGS. 1 to 8 in that the bulging portion 5 of the disc 1 and the annular plate 4 in the portion corresponding to the wide area portion 5a of the insertion hole 5 are respectively upward and This is the point that another inflating portion 8a, 4a protruding downward is provided in a predetermined length along the radial direction of the disc 1.

The bulging portions 8a and 4a are symmetrical to each other and are formed in an oval shape that is long at least in the radial direction of the annular plate 4, and a ceramic is provided between the bulging portions 4a and 8a. A spherical member 11 made of, for example, an elastic cutting blade cord holding member is rotatably accommodated.

Therefore, in this embodiment, the elastic cutting blade cord 7 having the optimum length for cutting the bush is prepared, and this is inserted from the outer peripheral side of the insertion hole 5 into the narrow region portion 5b and further pushed deeply. .

By this pushing operation, the elastic cutting blade cord 7 is rolled and retracted while partly contacting the spherical member 11, and the annular plate is moved from the right side (or the left side) of the spherical member 11 in FIG. 4 protrudes toward the inner peripheral side. Further, the elastic cutting blade cord 7 is bent and folded so as to bypass the back surface side of the spherical member 11 against the elastic force.

Further, following this folding back, as shown in FIG. 11, the spherical member 11 is pulled out from the left side (or right side) to the outer peripheral side of the insertion hole 5 through the narrow region portion 5b, and the pullout length is the outer periphery thereof. When the specified part on the side is reached,
A portion of the elastic cutting blade cord 7 projecting from the outer peripheral side, that is, the cutting blade side is pulled to bring the state as shown in FIG.

By this pulling operation, the elastic cutting blade cord 7 makes frictional contact while being biased in opposite directions on the insertion side and the extraction side, and also makes frictional contact with the disc 1 and the annular plate 4 in the narrow region 5b. And, while being pressed against the spherical member 11, it bends with a small curvature. Therefore, the elastic cutting blade cord 7 is prevented from being pulled out from the narrow region 5b of the insertion hole 5.

Further, when the cutting blade portion projecting from the outer peripheral side of the elastic cord 7 is strongly pulled, the spherical member 11 moves so as to bite into the narrow region 5b in the outer diameter direction of the annular plate 4. By this movement, the elastic cutting blade cord 7 becomes stronger, and the spherical member 11 and the narrow region portion 5b are strengthened.
It is pressed and held between and, and withdrawal is completely prevented.

In this embodiment, since the spherical member 11 can be rolled in any direction, it is possible to use the elastic cutting blade cord 7 having an outside diameter within a certain range, for example, a relatively small diameter. That is, even if the elastic cord 7 has a small outer diameter, it can be pinched between the elastic cord 7 and the narrow region portion 5b of the insertion hole 5, so that it can be sufficiently compressed and held.
Removal is sufficiently prevented.

In each of the above-mentioned embodiments, when the elastic cutting blade cord 7 is removed from the insertion hole 5 and replaced, the cutting blade portion side protruding outward is pushed in, and the annular plate 4 is pushed.
The bent tip portion 7 of the elastic cutting blade cord 7 facing the back side of the cylindrical member 6 or the spherical member 11 on the inner peripheral side of the
After a is pulled out to the inner peripheral side to be released, the cutting blade side of the elastic cutting blade cord 7 may be pulled to the outer peripheral side of the annular plate 4.

Further, in the case of the spherical member 11, when the elastic cutting blade cord 7 is pushed into the insertion hole 5 from the outer peripheral side of the annular plate 4, the spherical member 11 itself rolls in the wide region 5a in the radial direction. Alternatively, since it moves, the elastic cutting blade cord 7 can be taken out from the insertion hole 5 more easily and quickly.

Even if the spherical member 11 is changed to a columnar member that moves in the radial direction within a certain range along the guide groove or the guide hole, the same action and effect as above can be obtained. You can Further, a strip plate or the like may be used as the rotary plate.

[0045]

As described above, according to the first aspect of the present invention, there is an effect that the use efficiency of the elastic cord as a cutting blade can be improved without using an expensive and special elastic cutting blade cord. is there.

According to the second aspect of the invention, there is an effect that an elastic cord having a predetermined outer diameter can be easily and surely fixed to the rotary plate body with a short locking length.

According to the invention of claim 3, there is an effect that elastic cutting blade cords having different outer diameters can be easily and reliably fixed to the rotary plate with a short locking length.

[Brief description of drawings]

FIG. 1 is a plan view showing a rotary cutting blade device of a brush cutter according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is an end view showing an outer peripheral side opening end of an insertion hole in the rotary cutting blade device shown in FIG. 1.

5 is a sectional view taken along line VV in FIG.

6 is a sectional view taken along line VI-VI in FIG.

7 is an end view showing the outer peripheral side opening end of the insertion hole of the elastic cutting blade cord of FIG.

8 is a sectional view taken along line VIII-VIII in FIG.

FIG. 9 is a plan view showing a rotary cutting blade device of a brush cutter according to another embodiment of the present invention.

10 is a sectional view taken along line XX of FIG.

11 is a sectional view taken along line XI-XI of FIG.

12 is an end view showing an outer peripheral side opening end of an insertion hole in the rotary cutting blade device shown in FIG.

13 is a sectional view taken along line XIII-XIII in FIG.

14 is a sectional view taken along line XIV-XIV in FIG.

FIG. 15 is an end view showing the outer peripheral side opening end of the insertion hole of the elastic cutting blade cord of FIG. 11.

16 is a cross-sectional view taken along line XVI-XVI of FIG.

[Explanation of symbols]

 1 Rotating Plate 4 Annular Plate 5 Insertion Hole 5a Wide Area 5b Narrow Area 6 Cylindrical Member (Elastic Cutting Blade Cord Holding Member) 7 Elastic Cutting Blade Cord 7a End 11 Spherical Member (Elastic Cutting Blade Cord Holding Member)

Claims (3)

[Claims] 1. A rotary plate body (1) which is rotationally driven integrally with a rotary shaft of a brush cutter, and an inner peripheral side of the plate body (1) which is formed near an outer peripheral portion of the plate body (1). The insertion hole (5) of the elastic cutting blade cord (7) which is wide and narrow on the outer peripheral side is provided in the wide area portion (5a) of the insertion hole (5). The elastic cutting blade cord (7) inserted from the outer peripheral side of the narrow region portion (5b) is foldably supported, and the folded elastic cutting blade cord end portion (7a) is led out and held to the outer peripheral side. A rotary cutting blade device for a brush cutter, comprising an elastic cutting blade cord holding member (6, 11). 2. The elastic cutting blade cord holding member is a columnar member (6) fixed in the wide area portion (5a) of the insertion hole (5). Rotary cutting blade device for brush cutter. 3. The elastic cutting blade cord holding member is a spherical member (11) or a columnar member which is movably provided at least along a radial direction of the plate body (1) within a certain range. A rotary cutting blade device for a brush cutter, which is characterized in that