JPS6325960Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention enables the mower blade to be fixed in place without using fasteners such as bolts or nuts on the disk fixed to the tip of the drive shaft, and the circular plate of the mower blade This invention relates to a mower blade attachment device for a brush cutter that can be easily attached to and detached from a plate.

Conventionally, as a means for attaching a cutting blade to a disk in a brush cutter, for example, (i) as shown in FIG. There is a type in which the cutting blade 3 is fixed, but in this case, a crack occurs in the hole where the bolt passes due to the impact during the mowing operation, and the bolt and nut gradually loosen, causing the cutting blade 3 to become a disc. There is a risk that the cutting blade 3 may swing relative to the position shown in FIG. 1, or even be displaced from its initial setting position, making it difficult to perform grass cutting operations adequately. Therefore, as one means to prevent unnecessary swinging or displacement of the cutting blade, for example, (ii) as shown in FIG. The blades 6 are arranged radially, each of these cutting blades 6 is covered with a plate 7 having an inverted flat U-shaped cross section, and the bent pieces a, a of the plate 7 are formed in elongated holes b, b bored in the disc 5. While inserting the cutting blade 6 from the left and right sides, the disc 5,
The cutting blade 6 is initially set to the disc 5 by passing the bolts 8 through the bolt insertion holes c, d, and e drilled in the cutting blade 6 and the plate 7, respectively, and tightening the nut 9 at the lower end. The position is maintained. However, in the case of lever (ii), the bolt insertion hole c,
The occurrence of cracks in parts d and e is smaller than in case (i), but as mentioned above, vibrations and shocks during mowing work are propagated to the disk 5 and plate 7 via the cutting blade 6. It is difficult to completely prevent the occurrence of cracks, and weakening due to the occurrence of cracks especially in the vicinity of the bolt insertion holes c, d, and e is inevitable. This method has disadvantages such as being time-consuming. From the above, in the case of blades that are attached to a disc via fasteners such as bolts or nuts, although there are differences in degree,
It is inevitable that bolts and nuts will become weakened due to the occurrence of cracks in the attachment parts, and there is a high risk that the cutting blade may loosen from the disc or even detach from the disk due to repeated use. Therefore, this invention was developed with the intention of correcting the drawbacks of the above-mentioned means of attaching the cutting blade to the disc via bolts and nuts. In addition to preventing the risk of weakening due to the occurrence of cracks,
To attach a mower blade to a brush cutter, which can always maintain the initial setting position without swinging unnecessarily after the mower blade is set on the disc, and which can be easily attached to and detached from the disc. The aim is to provide equipment.

Hereinafter, this invention will be explained using examples with reference to FIGS. 4, 5, and 6. A spline S is carved on the lower outer circumferential edge of a drive shaft 12 which is interlocked with a transmission shaft 11 rotated by an engine (not shown), and a holder G and a fixture F are fitted above and below this spline S, respectively,
The protrusion p formed at the center of the holder G is fitted into the recess v at the center of the fixture F, and the through hole h formed in the center of the disc 13 is tightly attached to the outer periphery of the protrusion p. A part of the spline S side of this disc 13 is held between the holder G and the fixture F, and is brought into close contact with the spring washer W, which is fitted onto the lower surface of the fixture F. The lower part of the bolt j screwed into the drive shaft 12 is tightened with a nut n, and the drive shaft 12, the disk 13 fixture F, and the holder G are integrally connected. Further, on the outer peripheral edge of the disk 13, a pair of side edges K, K of a plurality of (three in this case) receptacles 14 each having a substantially inverted U-shaped cross section are attached to a fastening device r such as a screw or a stud. It is fixed by r or welding. However, as shown in FIGS. 5 and 6, the lever holder 14 is
Bent pieces u, u that are approximately trapezoidal and connected to side edges K, K
is tapered toward the outer peripheral edge of the disc 13 along the radial direction of the through hole h, and
A truncated, substantially triangular cutting blade 15 interposed between the holder 14 is inserted into and removed from the holder 14, and the abutting edge t of the cutting blade 15 on the side of the through hole h is connected to the fixed While being pressed against the outer periphery of the tool F, the side edges are brought into close contact with the inner sides of the folded pieces u, so that movement of the cutting blade 15 along the outer periphery of the disk 13 and in the radial direction is prevented in advance. In the figure,
16 is an oil seal, 17 is a ball bearing, 18 is a winding prevention piece, and i is a spline groove carved in the fixture F.

In this invention, while inserting the cutting blade 15 into the inside of the bent pieces u, u of the receiver 14 from the fitting hole h side,
The center of the fixture F is spline-fitted to the drive shaft 12, and the outer periphery of the fixture F presses the contact edge t of the cutting blade 15, so that the cutting blade 15 is tightly held and held by the receiver 14, while the fixture F prevents the cutting blade 15 from moving in the radial direction. Next, the holder G is brought into contact with the upper part of the disc 13, the bolt j is screwed into the drive shaft 12, and the lower end is tightened with the nut n.Then, when the engine is started, the power is transferred to the transmission shaft 11 and the drive shaft 12. Through the fixture F, the holder G disk 13 and the cutting blade 15
By rotating them together, the desired mowing operation is performed with the cutting blade 15. However, vibrations and shocks during the grass cutting operation are transmitted to the disc 13 through the cutting blade 15.
, the cutting blade 15 and the disc 13 are not fixed by a mounting device such as a bolt or nut that has a bolt insertion hole, so the disc 13 and the cutting blade 15 are not fixed due to the presence of the hole. Since there is no risk of cracks occurring, weakening of the attachment portion between the disc 13 and the cutting blade 15 can be prevented, and the cutting blade 15 can be attached to the holder 14.
The movement of the disk 13 along the outer periphery is prevented by
Moreover, due to the pressing force along the radial direction of the abutting edge t of the cutting blade 15 by the fixture F, the disk 13 is
Since movement in the radial direction of the cutting blade 15 is also prevented, the original position of the cutting blade 15 on the disk 13 can be well maintained even during repeated cutting operations, so that the loosening of the cutting blade 15 during the cutting operation is prevented. In addition, the disc 13 has a through hole h in its center.
is fitted into the protrusion p of the holder G, while a part of the drive shaft 12 side is sandwiched and tightly attached between the holder G and the fixture F, so that the disc 13 is Since the central part does not oscillate unexpectedly and can maintain its original position well, there is no risk of it loosening or swaying unexpectedly due to vibrations or shocks during mowing operations. When replacing, inspecting, or repairing the cutting blade 15, the holder G, the disk 13, and the fixture F can be easily separated by detaching the bolt j from the drive shaft 12. , the cutting blade 15 can be removed from the disc 13 from the contact edge t side without any complication. Furthermore, since there are no bolt insertion holes in either the disc 13 or the cutting blade 15, there is no risk of a decrease in strength, and there is no need to drill bolt insertion holes at all.
It is possible to supply a robust and inexpensive disc 13 and cutting blade 15 to general consumers, and the mounting and removal of the cutting blade 15 to and from the disc 13 can be easily handled by any person, which is very convenient for users. Moreover, the structure for assembling and removing the cutting blade 15 from the disc 13 is extremely simple.
Since it can be used for a long time without fear of failure during use, it has practical benefits such as being economical.

In this implementation, three cutting blades 15 are connected to the disk 13.
However, any number can be selected, and the shape of the fixture F is not limited to hexagonal.
It can take any form.

[Brief explanation of the drawing]

Fig. 1 is a front view of the main parts of a conventional brush cutter, Fig. 2 is an exploded perspective view of a cutting blade in another type of conventional brush cutter, Fig. 3 is an enlarged cross-sectional view taken along the - line in Fig. 2, and Fig. 4
The figure is a partially cutaway sectional view of the main part of the present invention, FIG. 5 is a bottom view when the cutting blade is attached to the disk, and FIG. 6 is an exploded perspective view. 12... Drive shaft, 13... Disc, 14... Receiver, 15... Cutting blade, F... Fixture, G... Holder, h... Through hole, j... Bolt, n... Natsuto,
p... protrusion, t... contact edge of the cutting blade 15, v...
recess.

Claims (1)

[Claims for Utility Model Registration] (1) A holder G and a fixture F are spline-fitted to the top and bottom of the drive shaft 12 driven by the engine, respectively, and the holder G is fitted into the recess v of the fixture F. A protrusion p is tightly fitted into the protrusion p, and a through hole h of a disc 13 having a plurality of receivers 14 fixed to the outer peripheral edge thereof is fitted into the protrusion p,
A part of the disc 13 on the drive shaft 12 side is held between the holder G and the fixture F, and the holder G, the fixture F, and the disc 13 are screwed onto the drive shaft 12. The lower part of the bolt j to be inserted is tightened with a nut n, and the receiver 14 is integrally connected.
A mower blade attachment device for a brush cutter, in which a contact edge t of a mower blade 15, which can be inserted and removed freely into and penetrated, is brought into contact with the outer peripheral edge of a fixture F. (2) The receiver 14 has a substantially trapezoidal cross section with an inverted U-shape,
The cutting blade attachment device for a brush cutter according to claim 1, wherein the cutting blade 15 is formed into a tapered shape, and the fixture F is formed into a polygonal shape.