JPH0541626Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial application field] This invention relates to the rotating head structure of a brush cutter used for mowing lawns and weeds. The present invention relates to a rotary head structure that can prevent the tip of the blade from being drawn into the rotary head.

[Conventional technology]

In Japanese Utility Model Publication No. 55-54885, an elastically compressible tapered member is fitted into a tapered insertion hole on the periphery of the housing of a rotary head, and a string-like cutting blade is inserted into the insertion hole of the tapered member. , the tapered member is pushed into and pulled out from the inside of the housing into the tapered hole, the string-like cutting blade is held releasably by the tapered member, and the length of the string-like cutting blade can be arbitrarily adjusted. I have to.

Utility Model Publication No. 56-18259 discloses that a centrifugal piece that rotates due to centrifugal force is provided around the housing of the rotary head, and when the rotary head is rotating, the string-like cutting blade is held by the centrifugal piece, and the string-like cutting blade is held by the centrifugal piece. At the time of exchange,
The centrifugal piece is opened and the grip part inserted from the outside of the housing so that it can be mounted on the rotating head.

In Japanese Utility Model Publication No. 57-4810, the rotary head is provided with an insertion hole that penetrates in the diametrical direction, a string-shaped cutting blade is inserted into the insertion hole, and a bolt is tightened from the bottom of the rotary head to remove the string. The shape of the cutting blade is kept in place.

In Japanese Utility Model Publication No. 59-32248, cord holes are provided in the metal weight element attached to the peripheral side plate and the rubber cord stopper, and the cord that passes through these cord holes and projects outward is The generated centrifugal force causes the metal weight particles to press against the cord stopper, and this pressure narrows the cord hole in the cord stopper, allowing the cord to be pulled out. I make sure to hold it.

[Problem to be solved by the invention] In the rotating head structure of Utility Model Publication No. 55-54885,
In order for the tapered member to hold the string-like cutting blade, the string-like cutting blade is fastened through the insertion hole of the tapered member.
Since it is difficult to pull out the tapered member from the housing, it is difficult to pull out the string-like cutting blade whose tip is located in the insertion hole of the tapered member outside the rotating head without disassembling the rotating head. It is.

The rotary head structure of Utility Model Publication No. 56-18259 and Utility Model Publication No. 57-4810 shows a structure that releasably holds or fixes the string-like cutting blade, but these do not require replacement of the entire string-like cutting blade. This is to make it easier to
Application to a brush cutter in which the string-like cutting blade is pulled out from a reel and used when the string-like cutting blade breaks at the base has not been considered and is difficult to apply.

In the structure described in Japanese Utility Model Publication No. 59-32248, when the housing is rotating, the centrifugal force pushes the metal weight outward, compressing the cord stopper and shrinking the cord hole of the cord stopper to grip the cord. However, when the centrifugal force no longer acts, the cord is no longer gripped by the cord stopper, so that if the cord is cut at the point where it comes out, the uncut end of the cord may be pulled into the housing.

The purpose of this invention is to prevent the string-like cutting blade from being drawn into the housing when it is cut off from the circumference of the rotating head, and to easily remove the string-like cutting blade from the housing. To provide a rotary head structure for a brush cutter that can be pulled out.

[Means to solve the problem]

This invention will be explained using reference numerals in the drawings that correspond to the embodiments.

In the brush cutter 10, the string-like cutting blade 24 is pulled out from an insertion hole 36 formed in the periphery of the housing 26. In the rotary head structure, a gripping part 38 that releasably grips the string-like cutting blade 24 is disposed within the housing 26 and near the insertion hole 36, and the gripping part 38 holds the string-like cutting blade 24 in a releasable manner. a displacement member 39 that has a through hole 44 and is supported by the housing 26 in a freely displaceable manner;
A receiving part 46 for receiving the string-shaped cutting blade 24 and a receiving part 46 having a guide hole 45 for guiding the tip of the cutting blade in the axial direction, and a converting member 39
and a spring 43 that urges the receiving portion 46 toward the receiving portion 46.

[Effect]

While the rotary head 20 is rotating, a centrifugal force is applied to the portion of the string-like cutting blade 24 on the distal side of the grip portion 38, and the string-like cutting blade 24 is strongly pulled outward in the radial direction of the rotating head 20. ing. When the string-like cutting blade 24 is cut at the base side, the cut point is at the housing 26.
This is the location of the insertion hole 36. When the rotation of the rotary head 20 is stopped, the insertion hole 3 is opened from the grip portion 38.
The centrifugal force that had been present in the string-like cutting blade 24 up to the point 6 disappears, and the part of the string-like cutting blade 24 in this range is
Due to the elasticity of the string-like cutting blade 24 itself, it contracts by the amount that has been pulled by the centrifugal force.
However, since the string-like cutting blade 24 is held in the receiving part 46, the uncut tip of the string-like cutting blade 24 remains in the housing 2 even after the rotary head 20 has stopped.
It is pulled inward only a little, and is in a position where it can be easily grasped from the outside of the housing 26. Therefore, the tip of the string-like cutting blade 24 is gripped from the outside of the housing 26, the holding part 38 releases the string-like cutting blade 24, and the string-like cutting blade 24 is pulled out from the housing 26.

Then, the displacement member 39 is biased by the spring 43 to cause the distal end thereof to enter the guide hole 45 . The string-like cutting blade 24 is bent at both ends of the through hole 44 of the displacement member 39 and is locked between the displacement member 39 and the guide hole 45, and is in a gripping state. Further, when the displacement member 39 is displaced upwardly with respect to the receiving portion 46 against the spring 43, the through hole 44 of the displacement member 39 is separated from the receiving portion 46 in the axial direction of the displacement member 39, and the string-like cutting blade 24 is Become a liberated state.

〔Example〕

This invention will be described below with reference to embodiments shown in 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 protrudes from the gear case 18 from below.
Rotates integrally with 2. The two string-like cutting blades 24 are
They are made of nylon rope or the like, and extend outward from opposite locations on the circumference of the drive shaft 22.

FIG. 1 is a vertical cross-sectional view of the periphery of rotary head 20. As shown in FIG. The rotary head 20 includes a housing 26, which is comprised of an upper portion 28 and a lower portion 30 that are removably joined from above and below. The reel 32 is disposed within the housing 26 and fixed at the center to a boss portion (not shown) of the upper portion 28 by a nut or the like so as to rotate integrally with the housing 26. The base 34 has an insertion hole 36 formed along its center line, and is fixed to the periphery of the housing 26 so as to pass through the insertion hole 36 from inside to outside. The string-like cutting blade 24 is wound around a reel 32, inserted into an insertion hole 36, and pulled out of the housing 26. Gripping part 38
is provided inside the housing 26 at a location near the insertion hole 36, and releasably grips the string-like cutting blade 24. The gripping portion 38 has a pressing rod 39, and is supported as a displacement member by the upper portion 28 so as to be freely displaceable in the axial direction. The stopper 40 is formed on the upper side of the press rod 39 and prevents the press rod 39 from falling into the housing 26 by coming into contact with the upper surface of the upper portion 28 . The C-ring 41 is fitted into the housing 26 at the location of the press rod 39, and the spring seat 42 is fitted onto the press rod 39 above the C-ring 41.
The compression coil spring 43 is fitted onto the press rod 39 and has both ends in contact with the lower surface of the upper portion 28 and the spring seat 42 .

The pressing rod 39 is provided with a through hole 44, which is formed so as to pass through the lower end of the pressing rod 39 in the diametrical direction and parallel to the insertion hole 36, and is formed so as to pass through the lower end of the pressing rod 39 in the diametrical direction. The shaped cutting blade 24 is passed through. The guide hole 45 is formed at the center of a hollow cylindrical receiving part 46 planted on the lower part 30, and guides the tip of the pressing rod 39 in the vertical direction. In a normal state, the pushing rod 39 has its tip end moved into the guide hole 45 by the biasing force of the compression coil spring 43 . The string-like cutting blade 24 is bent at both ends of the through hole 44 of the press rod 39 and is locked between the press rod 39 and the guide hole 45, and is in a gripping state. Furthermore, when the press rod 39 is pulled upward against the compression coil spring 43, the through hole 44 of the press rod 39 separates from the receiving portion 46 in the axial direction of the press rod 39, and the string-like cutting blade 24 becomes in a released state. .

Prior to starting the operation of the brush cutter 10, the push rod 39
is at a position sufficiently moved toward the receiving part 46,
The string-like cutting blade 24 is held between the through hole 44 and the receiving part 46. While the rotary head 20 is rotating, a centrifugal force is applied to the part of the string-like cutting blade 24 on the distal end side of the gripping part 38, and the string-like cutting blade 24
is strongly pulled radially outward. When the string-like cutting blade 24 is cut at the root side, the cut point is at the insertion hole 36 of the housing 26. When the rotation of the rotary head 20 is stopped, the centrifugal force exerted on the string-like cutting blade 24 from the grip portion 38 to the insertion hole 36 disappears, and the string-like cutting blade 2 in this range disappears.
Due to the elasticity of the string-like cutting blade 24 itself, the portion 4 shrinks by the amount that has been pulled by the centrifugal force. However, since the cord-like cutting blade 24 is held in the receiving part 46, the uncut string-like cutting blade 24
Even after the rotary head 20 has stopped, the tip of the blade 4 is only slightly retracted into the housing 26 and is in a position where it can be easily grasped from outside the housing 26. When the pressing rod 39 is moved upward, the string-like cutting blade 24 is released. In this way, the reel 32 is made rotatable with respect to the upper part 28 and the string-shaped cutting blade 24 is released, and then the tip of the string-shaped cutting blade 24 is grasped from the outside of the housing 26, and the string-shaped cutting blade 24 is held in a free state.
4 from the reel 32 and pulled out from the housing 26.

[Effect of idea]

The gripping part is disposed near the inside of the insertion hole on the periphery of the housing, and grips the string-like cutting blade in a releasable manner, so even if the string-like cutting blade is cut off at the base while the brush cutter is operating, it will not be damaged. When the string-like cutting blade is held by the gripping part, the uncut tip of the string-like cutting blade is pulled by the centrifugal force due to the disappearance of the centrifugal force due to the elasticity of the string-like cutting blade. Even though the housing is contracted, it is not pulled deep into the housing and is in a position where it can be grasped from the outside of the housing. Therefore, by grasping the tip of the string-like cutting blade from the outside of the housing and releasing the grip of the string-like cutting blade by the gripping part, it becomes possible to easily pull out the string-like cutting blade out of the housing. This makes it easier to deal with cutting the mower blade.

In addition, the string-like cutting blade is passed through the through hole of the displacement member, and the distal end of the displacement member enters the guide hole of the receiving part, and the string-like cutting blade is bent at both ends of the through hole of the displacement member and is in a locked state. This increases the gripping force of the cord-like cutting blade.

[Brief explanation of the drawing]

The drawings relate to an embodiment of the invention; FIG. 1 is a vertical cross-sectional view of the periphery 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, 26 ... Housing, 36 ... Insertion hole, 38 ... Grip section, 39 ... Pressing rod (displacement member), 43 ... Compression coil spring (spring), 44 ...
Through hole, 45... guide hole, 46... receiving part.

Claims (1)

[Scope of utility model registration request] In a rotary head structure of a brush cutter in which a string-like cutting blade 24 is pulled out to the outside from an insertion hole 36 formed on the periphery of a housing 26, the string-like cutting blade 2
4 is disposed in the housing 26 in the vicinity of the insertion hole 36, and the gripping part 38 releasably grips the cord-like cutting blade 2.
The housing 26 has a through hole 44 through which 4 is passed.
A displacement member 39 supported so as to be freely displaceable, and a guide hole 4 that guides the distal end of the displacement member 39 in the axial direction.
5 and a receiving portion 46 that receives the string-like cutting blade 24.
and a spring 43 that urges the displacement member 39 toward the receiving portion 46.