JPH0226267Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an output shaft locking device for a brush cutter that is capable of locking the output shaft when replacing a cutting blade.

[Conventional technology]

Conventionally, the output shaft that protrudes downward from the drive case connected to the tip of the operating rod can be held by an upper clamping body that can be fitted and fixed to the shaft, and a lower clamping body that can be fitted below the output shaft. In a brush cutter configured to fit a cutting blade and to fix the cutting blade to the output shaft by tightening a nut to the lower end of the output shaft, the output shaft can be locked when replacing the cutting blade. JP-A No. 59-98613 discloses a rod-shaped body that can be elastically engaged with the engagement hole of a winding prevention body, and an output shaft is attached to the winding prevention body and the upper clamping body. It is designed so that it can be inserted and locked from the direction perpendicular to the lock.

[Problem that the invention attempts to solve]

With such a structure, it is dangerous to set the rod-shaped object because it is close to the cutting blade, and the operation of inserting the rod-shaped object into the engagement hole of the upper clamping body must be performed with both hands. However, there are some problems that it is not easy to do.

The present invention aims to solve such problems, and provides a locking device that can be operated safely and easily with one hand, and has a simple structure that can be suitably implemented.

[Means for solving problems]

Therefore, in the present invention, a through hole that is approximately parallel to the axial direction of the output shaft is formed in the outer peripheral part of the drive case, and a recess that corresponds to the through hole is formed in the outer peripheral edge of the upper surface of the upper clamping member. A locking rod that can be removably inserted into the through hole and the recessed portion from above is provided, and at the upper part of the locking rod which is the upper side of the through hole, the periphery of the large eccentric side can be adjusted by rotating the locking rod. It is constructed by fixing an eccentric locking body that can press the surface against the outer peripheral surface of the drive case so that it does not come off.

[Effect]

Therefore, when the lower part of the locking rod is inserted into the through-hole from above and the upper clamping body is rotated while rotating the cutting blade with one hand, the locking rod will close when the recess rotates downward into the through-hole. It automatically falls into the recess due to its own weight, and when the locking rod is rotated from this state, the eccentric large side circumferential surface of the locking body comes into pressure contact with the outer circumferential surface of the drive case and cannot be removed.
From the state where the locking rod cannot be removed, the drive case is turned tightly so that the cutting blade faces upward, and the nut is loosened and tightened upward, allowing the cutting blade to be replaced safely and easily with one hand.

〔Example〕

Next, the embodiment shown in the drawings will be described.

FIG. 1 shows a cross-sectional view of the tip of the brush cutter, in which the tip of the operating rod 1 that extends from the engine side and houses the drive shaft 10 is obliquely connected to the side of the drive case A, and the bearing 11, Drive case A through 12
The upper part of the output shaft 2 mounted therein and the drive shaft 10 are transmission connected via bevel gears 13 and 14.

An umbrella-shaped anti-wrapping body 1 is mounted on the lower surface of the three mounting seats 15 protruding from the outer circumferential surface of the drive case A near the lower part.
The output shaft 2 is connected to the outer periphery of the upper surface of 6 and fixed with bolts 17, and is located inside the anti-wrapping body 16.
The center spline hole 3b of the upper clamping body 3 is fitted into the spline shaft part 2a of the upper clamping body 3, and a disc-shaped mower is inserted between the lower clamping body 4 loosely fitted on the output shaft 2 and the upper clamping body 3. Double nuts 5, 5 are screwed together and tightened to the threaded portion 2b at the lower end of the output shaft 2, which holds the blade B and projects downward, so that the structure is similar to the conventional structure.

A raised portion 18 is formed above the base side of the mounting seat 15 on the lateral side of the drive case A, and the mounting seat 15 is separated from the raised portion 18 slightly outwardly from the outer peripheral surface of the drive case A. A vertical through hole 6 that is substantially parallel to the axial direction of the output shaft 2 is formed at the base, and an outer peripheral edge 3a is formed in a ring shape on the outer periphery of the upper surface of the upper holding body 3 so as to be below the through hole 6. A vertical recess 7 corresponding to the lower side of the through hole 6 is formed by cutting out a part of the through hole 6 .

Reference numeral 8 denotes a locking rod in the shape of a round bar, on the upper part of which a gripping part 8a is bent, and on the upper side of the locking rod 8 there is a center portion of an oval rubber locking body 9 having a certain thickness. are assembled by fitting and welding.

Therefore, as shown in FIG.
drop the locking rod 8 into the through hole 6 from above so that the lower end rests on the upper surface of the outer peripheral edge 3a of the upper clamping body 3 without contacting the outer peripheral surface of the drive case A, and from this state, cut with one hand. When the upper clamping body 3 is rotated while rotating the blade B, the 11th
As shown in the figure, the lower end of the locking rod 8 falls into the recess 7 and is inserted into the gripping portion 8.
Hold a and rotate locking rod 8 about 90 degrees,
As shown in Figures 12 and 13, the locking rod 8
is in pressure contact with the inner surface of the through hole 6, and the locking body 9
The large eccentric side circumferential surface of the drive case A is bent and press-contacted with the outer circumferential surface of the drive case A, and in this state, the output shaft 2 can be locked while preventing the locking rod 8 from coming off.

From this state, the drive case A is turned upside down so that the cutting blade B faces upward, and the cutting blade B can be replaced with one hand while operating the nuts 5, 5.

[Effect of idea]

In this way, in the present invention, when the locking rod 8 is dropped into the through hole 6 and the cutting blade B is rotated with one hand, the locking rod 8 is inserted into the recess 7 of the rotating upper clamping body 3.
When the lower ends of the locking body 9 match, the output shaft 2 can be automatically inserted and the output shaft 2 can be locked, and the operating rod 8 is rotated to press the large eccentric side circumferential surface of the locking body 9 against the outer circumferential surface of the drive case A. Then, the locking rod 8 can be kept in a state where it cannot be removed, and the work of replacing the cutting blade B can be done safely and easily by turning it over so that the cutting blade B is facing upward. It has the advantage that it can be performed safely, reliably and quickly even with one hand, and that it can be carried out suitably with a simple structure.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the main parts of an embodiment of the present invention.
Fig. 2 is a side view of the drive case, Fig. 3 is a plan view thereof, Fig. 4 is a side view of the upper clamping body, and Fig. 5 is a side view of the drive case.
6 is a sectional view of a part of the drive case and upper clamping body, FIG. 7 is a front view of the locking rod, FIG. 8 is a side view thereof, and FIG.
A sectional view taken along the - line in the figure, FIGS. 10 to 12 each show an explanatory view of the operation, and FIG. 13 shows a plan view of the state shown in FIG. 12. 11... Operating rod, A... Drive case, 2... Output shaft, 3... Upper clamping body, 4... Lower clamping body, 5
... Nut, 6 ... Through hole, 3a ... Outer periphery, 7
... recess, 8 ... locking rod, 9 ... locking body.

Claims (1)

[Scope of utility model registration request] An output shaft 2 protruding downward from the drive case A connected to the tip of the operating rod 1 has an upper clamping body 3 that can be fitted and fixed to the shaft 2, and a lower clamping body 4 that fits below the output shaft 2. In a brush cutter configured to fit a cutting blade B that can be held between the drive case A and to fix the cutting blade B to the output shaft 2 by tightening a nut 5 to the lower end side of the output shaft 2, A through hole 6 that is substantially parallel to the axial direction of the output shaft 2 is formed in the outer peripheral portion, and a recess 7 corresponding to the through hole 6 is formed in the upper surface side outer peripheral edge 3a of the upper holding body 3. In addition to providing a locking rod 8 that can be detachably inserted into the through hole 6 and the recess 7 from above,
At the upper part of the locking rod 8 which is located above the through hole 6, by rotating the locking rod 8, the circumferential surface on the larger eccentric side can be pressed against the outer circumferential surface of the drive case A so as not to come off. An output shaft locking device characterized in that it is constructed by fixing an eccentric locking body 9.