JPH0626105Y2 - Cutting blade mounting device for brush cutter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a cutting blade mounting device for a brush cutter, and more specifically, to the output shaft of a gear case of the brush cutter, without cutting the cutting blade with screws. The cutting blade can be securely clamped by the friction plate by the centrifugal force generated by the rotation, and the cutting blade can be attached and detached by one-touch operation, and the cutting blade does not drop accidentally and is safe. The present invention relates to a cutting blade mounting device capable of performing various mowing work.

[Conventional technology]

In many of the conventionally known brush cutters, a small engine as a power source is attached to one end of the operating main rod, and the output of this engine is passed through a transmission shaft that penetrates through the inside of the operating main rod. Input to a gear case provided at the other end of the operating main rod, and is configured so that the cutting blade is fastened and fixed by the cutting blade retainer attached to the output shaft of the gear case and the fastening washer of the cutting blade. It is a thing.

More specifically, a disc-shaped cutting blade presser is integrally fixed to the output shaft, and a cutting blade closely attached to the cutting blade presser is fitted on the output shaft, and a male screw portion formed on the output shaft. The cutting blade is fastened to the output shaft by screwing the fixing nut into the.

However, since the cutting blade can rotate at a high speed of several thousand revolutions per minute, if the cutting blade may fall off during high-speed rotation, the cutting blade will rotate around and the accident will occur. Will be caused.

Therefore, the cutting blade is often fastened to the output shaft with a double nut for safety.

For this reason, double-nut tightening and loosening work are necessary when installing or replacing the cutting blade, which is very troublesome and may not be possible for women and women who have little knowledge of the machine. Also, since the output shaft is normally rotated counterclockwise, it is fastened with the direction of rotation and the reverse screw, so if an unskilled worker replaces the cutting blade, secure fastening may not be performed. It is very dangerous.

Therefore, the applicant can remove and attach the cutting blade with a relatively simple operation, and the faster the cutting blade can be rotated, the tighter the cutting blade can be fastened and fixed. Is provided with a mounting device that functions as a safety device (for example, Japanese Utility Model Application No. 63-123350).

[Problems to be solved by the device]

The mounting device as described above is very convenient for sandwiching and fixing the cutting blade, but requires a simple and reliable attachment / detachment structure for attaching / detaching the cutting blade attachment device to / from the output shaft. Therefore, there was anxiety about the careless removal of the cutting blade attachment device from the output shaft.

Therefore, this invention not only clamps the cutting blade by the frictional force, but also makes it possible to attach and detach the cutting blade attaching device to the output shaft by a mechanical structure, but it is easy and easy to attach and detach. The purpose of the present invention is to provide a secure attachment device that does not come off.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention has an engine at one end of an operating main rod, a gear case at the other end, and a cutting blade retainer and a fastening base attached to the output shaft of the gear case. A brush cutter configured to clamp and fix the cutting blade by crimping the friction plate attached to the fastening table to the cutting blade holding side by centrifugal force applied to the moving element housed in the fastening table. In the cutting blade attaching device, a hook unit attached to the output shaft and a fastening base that can be detachably locked to the hook unit are provided, and the hook unit is provided in a plane parallel to the rotation surface of the cutting blade. The supported shaft allows sliding and rotating surfaces, and the hook is formed on the fastening table parallel to the axis of the hook unit while being constantly elastically pressed in one direction along the axis. The stopper is locked and the rotation of the shaft is restricted. The hook is placed in a rotatable state with respect to the shaft that slides in a predetermined position against elastic pressure by an unlocking mechanism provided on the fastening base, It is characterized in that the fastening table is configured to be separable.

(Operation) The fastening base is fitted to the hook unit integrally hung from the boss portion screwed to the output shaft, and in the fitting process, the locking portion of the fastening base fits inside the hook unit. While abutting on the pivotally supported hook and rotating it, the engaging portion engages with the hook, and the hook is elastically pressed and slid in one direction within the support wall of the hook unit to rotate. When the fastening base is completely attached to the hook unit due to regulation, and when it is removed, it can be rotated by operating the locking release mechanism of the fastening base and sliding the hook to a predetermined position against the elastic pressure. Then, if you move the fastening table downwards,
The hook rotates to release the engagement with the fastening base and can be easily removed.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. First, FIG. 1 is a partial cross-sectional view showing a cutting blade of a brush cutter and an output shaft portion of a gear case to which the cutting blade is attached. Reference numeral 1 denotes a cutting blade retainer arranged on a lower end surface of the gear case,
Reference numeral 2 denotes an output shaft protruding from the gear case. The cutting blade retainer 1 is screwed onto the first-stage screw portion 2A of the output shaft 2, and the boss portion 3 is attached to the second-stage screw portion 2B of the output shaft. Is screwed on.

The boss portion 3 has a female screw portion 3A which is screwed into the screw portion 2B, and side walls 31 and 32, which are constituent members of the hook unit 5 described later in detail, are arranged opposite to each other on the lower side thereof.
There is a space 3B between 1 and 32, and the side wall 3 that forms the space 3B
Reference numerals 1 and 32 have a point-symmetrical shape with each other, and step upper surfaces 31B and 32B projecting inward from the inner side surfaces 31A and 32A of the side walls 31 and 32 are formed, and the step upper surfaces 31B and 32B and the inner side surface 31A are formed. , 32A is at a right angle. The width of the upper surface of the step portion is such that the hooked state described later can be held.

Then, in the space 3B sandwiched between the side walls 31 and 32, the shaft 51, the hook 52, and the like that are touched previously are attached.

Further, a fastening base 4 is fitted on the boss portion 3, and a ball accommodating space 42 is formed in an upper end portion 41 of the fastening base 4, and the ball accommodating space 42 has an upper end surface opened. The inner bottom surface 43 has a slope that is shallow on the outside and deep on the inside. The open surface of the ball storage space 42 is covered with a leaf spring 44 as a friction plate, and the inner peripheral end portion of the leaf spring 44 is covered.
44A is fixed to the inner peripheral edge of the upper end of the boss portion 45 of the fastening base 4. Balls 46, which are typified by bearing balls as moving elements, are housed in the ball housing space 42 side by side in the circumferential direction. When the balls 46 receive a centrifugal force, the leaf springs 44, especially the free edges 44B, are pushed up. , The cutting blade K is pushed toward the cutting blade retainer 1 so that it can be clamped between the two.

The hook unit 5 is located in the space 3B sandwiched between the side walls 31 and 32, which are constituent members of the hook unit provided below the female screw portion 3A of the boss 3, and is located on the left and right sides of the rotation center. In parallel, a pair of shafts 51 are arranged with their both ends axially attached to the side walls 31, 32 along a plane parallel to the rotation surface, and the shafts 51 are axially movable. And,
A hook 52 is rotatably attached.
The hook 52 is pushed in one direction by a push spring 53 and is pressed against the inner side surfaces 31A, 32A of the side walls 31, 32 of the space 3B, and the lower surface 52A of the hook 52 is in a state perpendicular to the inner side surfaces 31A, 32A. It is placed on a certain step upper surface 31B, 32B.

The hook 52 has a V-shaped notch 52B on the end face of the pivotal support end.
The cut groove 52B catches the engaging portion 47 formed with a protrusion in an inverted V shape in parallel with the shaft 51 inside the space inside the fastening base 4.

A lock release mechanism 6 is provided inside the fastening base so that the hook unit 5 can be operated from both sides of the space 4A of the fastening base 4 into which the hook unit 5 can be inserted. That is, the notch 61 is formed on the bottom surface of the fastening base 4, and the cylinder-shaped space 62 is formed continuously with the notch 61. A piston-type spring bearing 63 is accommodated in this space 62, the open end is closed by a nut lid 62A, and an open rod 64 extending from the spring bearing 63 projects through the nut lid 62A. There is. That is, one end of the open rod 64
64A extends toward the hook unit 5 and the other end 64B
The push spring 65 in the space 62 acts on the spring receiver 63 to project into the notch 61 through the nut lid 62A, and has a flange 64X as a finger clasp at the tip.

A rubber cap 7 for covering the hook unit 5 is provided in the space 4A inside the fastening table 4.

Next, the work of mounting the cutting blade by the cutting blade mounting device according to the present invention will be described. First, when the hook 52 inside the space 3B is on the step upper surfaces 31B and 32B, since the movement in the rotation direction is restricted, the hook 52 is lowered from the step upper surfaces 31B and 32B. In order to lower the hook 52 on 31B, 32B, the release rod 64 of the locking release mechanism 6 is pushed in resisting the elasticity of the push spring 65, and the one end 64A pushes the pushing point 52X of the hook 52. As a result, the hook 52 has the step 31
B and 32B can be slid to an unlimited range and hook 5
The lower surface 52A of 2 is not restricted in any way, is free to rotate, rotates about the shaft 51 as shown in FIG. 2, and the cut groove 52B is in a state in which the fastening table 4 can be attached slightly downward.

When the fastening base 4 is fitted onto the boss portion 3 from the lower side in this state, the engaging portion 47 of the fastening base 4 rotates upward together with the hook 52 in the process (FIG. 1).

In this state, the notch 52B of the hook 52 is horizontal in the drawing, and the rotation is blocked, and the hook 52
It is placed in a state of being pressed against the inner side surfaces 31A, 32A of the side plates 31, 32 by 53, and is restrained in both the axial direction and the rotational direction (Fig. 4A). That is, the hook 52 is
When pressed against A and 32A, the lower surface 52A of the hook 52 rests on the upper surfaces 31B and 32B of the stepped portion, so that rotation is prevented, in other words, the fastening base 4 is prevented from falling off the boss portion 3. Are locked.

When removing the fastening base 4 from the boss portion 3,
When the releasing rod 64 of the locking and releasing mechanism 6 is pushed against the pushing spring 65, the pushing point 52X shown in FIG.
By pushing with 4A, the lower surface 52A of the hook 52 is slid to a predetermined position where the lower surface 52A is disengaged from the step upper surfaces 31B and 32B, and in other words, the hook 52 is deregulated in the rotation direction.

Therefore, pulling down the fastening table 4 causes
From the state shown in FIG. 7, the locking portion 47 of the fastening base 4 is rotated together with the hook 52, the cut groove 52B of the hook 52 is directed downward, and the fastening base 4 can be released (FIG. 2, And FIG. 4B).

During operation of the brush cutter, the ball 46 receives a centrifugal force and moves outward to push up the leaf spring 44, and the blade K passes through the leaf spring 44.
Press against the cutting blade holder 1 and fix.

[Effect of device]

As is clear from the above description, the cutting blade mounting device of the present invention is not limited to the cutting blade not only being clamped by the cutting blade retainer screwed on the output shaft and the friction plate of the fastening base, but also the fastening blade. The base can be attached to the hook unit that is integrated with the boss that is screwed onto the output shaft by mechanically connecting the locking part and the hook, and can be separated unless the fastening base is artificially removed from the hook unit. Since the cutting blade cannot be removed, the cutting blade can be easily replaced without requiring a tool for removal, and the cutting blade does not fall off, which is extremely useful for safety measures.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of an essential part of the cutting blade mounting device according to the present invention, FIG. 2 is an explanatory view showing the relationship between a hook unit and a locking portion during mounting, and FIG. 3 is FIG. A sectional view taken along line III and FIGS. 4 (A) and 4 (B) are explanatory front views of the hook unit. 1 …… Suppressing blade, 2 …… Output shaft, 2A, 2B …… Screw part, 3 …… Boss part, 3A …… Female thread part, 3B …… Space, 31, 32 …… Side wall, 31A, 32A …… Inner side surface, 31B, 32B …… step upper surface, 4 …… tightening table, 4A …… space, 41 …… upper end, 42 …… ball storage space, 43 …… bottom surface, 44 …… leaf spring, 44A… … Inner peripheral edge, 44B… Free edge, 45 …… Boss, 46
…… Ball, 47 …… Locking part, 48 …… Release rod, 48A …… Pressing spring, 49 …… Notch, 5 …… Hook unit, 51 …… Shaft, 52 …… Hook, 52A
...... Lower surface, 52B …… Incision groove, 52X …… Pressing point, 53 …… Pressing spring, 6 …… Lock release mechanism, 61 …… Notch, 62 …… Space, 63 …… Spring bearing, 64 …… Release rod, 64A ... One end, 64B ... The other end, 64X ... Nut lid, 65 ... Press spring,

Claims (1)

[Scope of utility model registration request] 1. An operating main rod has an engine at one end thereof and a gear case at the other end thereof, and is provided with a cutting blade retainer and a fastening base mounted on an output shaft of the gear case, and housed in the fastening base. In the cutting blade mounting device of the brush cutter, the friction plate attached to the fastening base is pressed against the cutting blade restraining side by centrifugal force applied to the moving element to clamp and fix the cutting blade. A hook unit attached to the hook unit and a fastening base that can be detachably locked to the hook unit, and the hook unit is slidable by a shaft supported in a plane parallel to the rotation surface of the cutting blade. It is possible to rotate,
In addition, the hook always locks the locking portion formed in parallel with the axis of the hook unit on the fastening base while being elastically pressed in one direction along the axis, and is rotationally regulated with respect to the axis. The hook is in a state in which it can be rotated with respect to the shaft that slides in a predetermined position against elastic pressure by an unlocking mechanism provided on the fastening table, A cutting blade mounting device characterized in that the mounting base is configured to be separable.