JPH052989Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a string-like cutting blade holding structure of a brush cutter used for mowing lawns and weeds, etc. This invention relates to a string-like cutting blade holding structure that allows the tip of the string-like cutting blade to be easily pulled out of a rotating head.

[Conventional technology]

In the brush cutter described in Japanese Utility Model Publication No. 55-54885, a wedge member is fitted into an outwardly tapered inclined hole in the circumference of a rotary plate (rotary head of this invention), and the wedge member is inserted into a hole in the wedge member. A flexible wire (the cord-like cutting blade of this invention) is inserted through the wedge member, and the wedge member is pushed into or pulled out from the inclined hole to replace or adjust the length of the flexible wire.

[The problem that the idea attempts to solve]

In the conventional brush cutter as described above, it is possible to pull out the string-like cutting blade from the rotating head when it comes out from the rotating head, but the string-like cutting blade does not fit into the insertion hole of the rotating head. If the blade is cut at the edge of the blade, it will be difficult to grasp the tip of the blade from the outside of the rotating head. If a structure is adopted in which the blade can be pulled out from the insertion hole in the blade, it will be necessary to disassemble the rotary head and pull out the string-like cutting blade from inside.

The purpose of this invention is to remove the string-like cutting blade wound on the reel provided inside the rotating head from the outside of the rotating head even if the string-like cutting blade is cut off from the circumference of the rotating head. To provide a string-like cutting blade holding structure for a brush cutter that can be easily pulled out.

[Means to solve the problem]

That is, the string-shaped cutting blade holding structure of the brush cutter according to this invention includes a reel 30 around which the string-shaped cutting blade 24 is wound, which is provided on the rotating head 20 so as to protrude outward from the periphery of the rotating head 20, and formed inside the reel 30. insertion hole 38
a protruding member 34 having a tapered inner circumferential portion 40 whose diameter increases outwardly at the outer end thereof;
a sleeve 44 having a tapered outer periphery 46 that fits into the sleeve 44; and a string extending from the inside of the rotary head 20 to the outside through the insertion hole 38 of the protruding member 34 and the insertion hole 48 formed in the sleeve 44. The shaped cutting blade 24 and the sleeve 44 are connected to the protruding member 34.
It has a screwing member 50 which is formed with a driving portion 52 and screwed onto the outer periphery of the protruding member 34 .

[Effect]

During use of the brush cutter 10, the threaded member 50 is deeply screwed into the protruding member 34, and the sleeve 44 is pressed toward the protruding member 34 by the entraining portion 52 of the threaded member 50, and the sleeve 44 is pressed against the protruding member 34. The tapered outer periphery 46 is deeply fitted into the tapered inner periphery 40 of the protruding member 34, thereby elastically compressing the sleeve 44 in its radial direction. Therefore, the string-like cutting blade 24 unwound from the reel 24 is firmly held in the insertion hole 46 by the sleeve 44.

During rotation of the rotary head 20, when the string-like cutting blade 24 is cut at the base end of its exposed range, the rotary head 2
Stop rotation of 0. As a result, the string-like cutting blade 24
Since the centrifugal force applied to the blade disappears, the remaining string-shaped cutting blade 24 contracts and tends to be drawn into the rotary head 20. However, in order to hold the cord-like cutting blade 24 within the insertion hole 48 of the sleeve 44, the rotary head 2
The cord-like cutting blade 24 is prevented from being drawn into the 0. When pulling out the string-like cutting blade 24, pull out the sleeve 44.
While maintaining the grip on the string-like cutting blade 24 , the threaded member 50 is loosened and the sleeve 44 is pulled out from the protruding member 34 . Along with this, the string-shaped cutting blade 24 is pulled out from the rotating head 20, and after the string-shaped cutting blade 24 is fully pulled out through the insertion hole 48 of the sleeve 44, the threaded member 50 is tightened to the protruding member 34 again. The tapered outer peripheral portion 46 of the sleeve 44 is connected to the protruding member 34.
into the tapered inner circumferential portion 40 of.

〔Example〕

This invention will be described below with reference to embodiments of the drawings.

FIG. 2 is a schematic overall view of the brush cutter 10.
A power section 14 is attached to the upper end of the pipe 12, and a handle 16 is attached to the upper end of the pipe 12 near the power section 14.
It is fixed at two points and extends upward. The gear case 18 is attached to the lower end of the pipe 12, and the rotating head 20 is fixed to a drive shaft 22 that projects downward from the gear case 18, and rotates integrally with the drive shaft 22. The two string-like cutting blades 24 extend outward from opposite locations on the circumference of the drive shaft 22 .

FIG. 1 is a vertical cross-sectional view of one half of rotary head 20. FIG. The lower housing portion 26 of the rotary head 20 has a cylindrical peripheral wall 27, closed at the bottom and open at the top. The upper housing part 28 is arranged to close off the upper part of the lower housing part 26, and the lower housing part 26 is releasably coupled to the upper housing part 28. The reel 30 is housed in an internal space formed by the lower housing part 26 and the upper housing part 28, is fixed to the lower surface of the upper housing part 28, and has the string-like cutting blade 24 wound thereon. The protruding member 34 is fitted into the circumferential wall 27 and fixed to the circumferential wall 27 until its flange 36 comes into contact with the outer surface of the circumferential wall 27 . The insertion hole 38 is formed to pass through the protruding member 34 along its center line, and the outer end of the insertion hole 38 becomes a tapered inner peripheral portion 40 whose diameter increases outwardly. ing. The thread groove 42 is connected to the flange 36 in the axial direction.
It is formed in the outer peripheral range of the protruding member 34 on the outer side. The sleeve 44 is made of an elastically compressible material such as rubber or soft resin, and has a tapered outer periphery 46 that matches the shape of the tapered inner periphery 40. 40, and an insertion hole 48 is formed along the center line. The string-like cutting blade 24 has an insertion hole 38,
48 to the exterior of the rotary head 20. The wing nut 50 has a reduced diameter portion 52 that comes into contact with the back side end of the tapered outer peripheral portion 46, and the sleeve 4
The tapered outer peripheral portion 46 of the projecting member 34 is placed inside, and has a thread groove 54 that can be screwed into the thread groove 42 of the protruding member 34. The pair of gripping portions 56 are integrally formed with the boss portion of the wing nut 50, protrude outward in the radial direction of the wing nut 50, and can be gripped by an operator.

The operation of the embodiment will be explained.

During use of the brush cutter 10, the wing nut 50 is deeply screwed into the protruding member 34, and the sleeve 44 is pressed toward the protruding member 34 by the reduced diameter portion 52 of the wing nut 50, so that the tapered outer circumference of the sleeve 44 Part 4
6 is deeply fitted into the tapered inner peripheral portion 40 of the protruding member 34, thereby elastically compressing the sleeve 44 in its radial direction. Therefore, the string-like cutting blade 24 is firmly held in the insertion hole 48 of the sleeve 44.

During rotation of the rotary head 20, when the string-like cutting blade 24 is cut at a point where it starts to be exposed from the sleeve 44, the remaining string-like cutting blade 24 is cut off due to the loss of centrifugal force applied to the string-like cutting blade 24. is about to contract and be drawn into the rotating head 20. However, due to the gripping of the cord cutting blade 24 within the insertion hole 48 of the sleeve 44, the pulling of the cord cutting blade 24 into the rotary head 20 is avoided. When pulling out the string-like cutting blade 24, while maintaining the grip of the string-like cutting blade 24 by the sleeve 44, loosen the wing nut 50, and pull out the sleeve 44.
is pulled out from the protruding member 34. Along with this, the string-shaped cutting blade 24 is pulled out from the reel 30 in the rotary head 20, and after the string-shaped cutting blade 24 is fully pulled out through the insertion hole 48 of the sleeve 44, the wing nut 50 is pulled out again from the protruding member 34. Tighten the sleeve 44
The tapered outer circumferential portion 46 of is pushed into the tapered inner circumferential portion 40 of the protruding member 34 .

[Effect of idea]

In this invention, even if the string-like cutting blade is cut at the circumference of the rotary head by pushing the tapered outer circumference of the sleeve into the tapered inner circumference of the protruding member by the threaded member, the cutting blade remains inside the insertion hole of the sleeve. By being elastically held in place, the string-like cutting blade is prevented from being drawn into the rotating head, and by loosening the threaded member, the tapered inner circumferential portion of the protruding member is attached to the tapered outer circumferential portion. When the engaged sleeve is pulled out from the projecting member, the string-like cutting blade is also pulled out from the rotating head, so that the string-like cutting blade can be pulled out without disassembling the rotating head.

Therefore, the trouble of disassembling the rotary head is saved, and the repair work involved in cutting the cord-like cutting blade can be greatly simplified.

[Brief explanation of drawings]

The drawings relate to an embodiment of the invention; FIG. 1 is a vertical sectional view of one half of the rotary head, and FIG. 2 is a schematic overall view of the brush cutter. 10...brush cutter, 20...rotary head, 24...
... String cutting blade, 27 ... Peripheral wall (periphery), 34 ... Projection member, 38, 48 ... Insertion hole, 40 ... Tapered inner peripheral part, 44 ... Sleeve, 46 ... Tapered outer peripheral part , 50...wing nut (screwing member), 52...
...Reduced diameter part (leading part).

Claims (1)

[Scope of utility model registration request] A rotary head 20 that accommodates a reel 30 around which a string-like cutting blade 24 is wound, and an insertion hole 3 formed inside and protruding outward from the periphery of this rotary head 20.
a protruding member 34 having a tapered inner circumferential portion 40 whose diameter increases outwardly at the outer end of the projecting member 34;
a sleeve 44 having a tapered outer circumferential portion 46 that fits into the rotary head 20; A threaded member 50 is formed with a string-like cutting blade 24 and a driving portion 52 that guides the sleeve 44 toward the protruding member 34 and is threaded onto the outer periphery of the protruding member 34.
A cord-like cutting blade holding structure for a brush cutter, characterized in that it has the following.