JPS6124038Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention dampens engine vibration in stages,
The present invention relates to a vibration isolating device for a brush cutter that can achieve effective vibration isolation.

In conventional brush cutters, engine vibrations are transmitted from the transmission shaft to the operator via the handle, which not only increases work fatigue but also, in severe cases, can cause the operator's capillaries to be severed. It is the cause of white wax. Therefore, as a vibration isolator for a brush cutter, for example, Japanese Utility Model Publication No. 48-24600,
There is one disclosed in Utility Model Publication No. 52-812. The vibration isolator described in the former is provided with a flange in the middle of the torque tube that accommodates the drive shaft, and this flange is attached to the flange on one end of the vibration isolator via a vibration isolator, and the other end of the vibration isolator is attached to the flange on one end of the vibration isolator. The side flange is attached to the engine mounting part via a vibration isolator. However, the prevention of engine vibration is achieved only by a buffer member or vibration isolator, and as a result, engine vibrations are not effectively isolated, resulting in a disadvantage that the vibration-proofing effect is small and the configuration becomes complicated. There is. In addition, the vibration isolating device described in the latter includes a vibration isolating rubber interposed between the inside of the reduced diameter part of the connecting part casing and the outer periphery of the handle rod, and also connects the collar of the handle rod holder and the flange of the bearing case as well as the collar. Anti-vibration rubber is interposed between the back walls of the enlarged diameter part of the casing, and the handle holder is attached to the prime mover, bearing case,
The bearing case is not brought into direct contact with the connecting part casing, and the bearing case and the connecting part casing are connected and tightened with bolts. However, in this configuration, although multiple anti-vibration rubbers are provided, the anti-vibration function is actually performed by one anti-vibration rubber, so the anti-vibration effect is small and the configuration becomes complicated. There is.

Therefore, the purpose of the present invention is to eliminate the above-mentioned disadvantages, simplify the configuration, and provide a brush cutter that can achieve effective vibration isolation by configuring the vibration isolation of the connection part to be attenuated in stages. The goal is to realize a vibration isolator.

Embodiments of the present invention will be described in detail and specifically below based on the drawings.

In Figures 1 to 3, 2 is a brush cutter, 3 is a handle, 4 is an engine, 6 is a clutch drum, 8 is a clutch case, 10 is a transmission shaft, 12 is a transmission shaft outer tube containing the transmission shaft, and 13 is a gear case. , 14 is a cutting blade, and 16 is a connecting portion.

In FIG. 2, which is an enlarged cross-section of the connecting portion 16,
A vibration isolating device is configured in two stages in the connecting portion 16. That is, a first member 18 made of a vibration isolating material such as rubber is fitted onto the protruding end 8a of the clutch case 8, and a presser fitting 22 is attached to the outer surface of the first member 18.
to be installed. Further, the second member 20 is externally fitted onto the rear end portion 12a of the transmission off-axis tube 12, and the outermost edge of the rear end portion 12a of the transmission off-axis tube 12 is folded and expanded to form a flange 12f. A shaped outer tube receiving fitting 24 is fitted onto the transmission shaft outer tube 12, and the second member 20 is fixed onto the outer tube receiving fitting 24. An end portion 24a of the outer tube receiving fitting 24 is slightly protruded from the second member 20, and a tightening fitting 26 is externally fitted onto the end portion 24a. A presser fitting 28 is fitted onto the second member 20. Further, a connection fitting 21 is fitted over the presser metal fittings 22 and 28 and connects the first member 18 and the second member 20 under the presser metal fittings from the outside in a vibration-proof manner. It is fixed to the first and second members 18 and 20 by fixing tools 30.... In addition, the code|symbol 32 is a washer, and this washer 32
constitutes a sliding surface with the flange 12f of the transmission off-axis tube 12, and is in contact with the rearmost edge of the transmission off-axis tube 12 facing the protruding end 8a of the clutch case 8.

Since this invention is constructed as described above, it operates as follows.

First, vibrations generated in the engine 4 are transmitted through the clutch drum 6 and clutch case 8 to the transmission off-axis tube 1.
2. At this time, part of the vibration is transmitted to the clutch case 8, the first member 18, the washer 32, and the second member 2, as indicated by the arrow 34 in FIG.
0 and is not finally transmitted to the transmission off-axis tube 12. In addition, most of the remaining vibrations pass through the clutch case 8, the first member 18, the presser fitting 22, the connecting fitting 21, and the other presser fitting 28, as shown by the arrow 36.
It is assumed that it is not transmitted to the transmission off-axis tube 12 via the second member 20 and the outer tube receiving fitting 24. and,
These vibrations tend to vibrate the handle 3 and adversely affect the operator. However, as shown in FIG. 2, some of the vibrations are damped while passing through the path of arrow 34 having the required distance. Further, the remaining vibration is transmitted to the second member via the first member 18 and the connecting fitting 21.
Pass through the path of arrow 36 of member 20. In other words,
The remaining vibrations pass through the path indicated by arrow 36, which is larger than the path indicated by arrow 34, and are therefore efficiently damped during this period. Therefore, the total vibration of the engine 4 is
While being dispersed, the first member 18 and the second member 2
Since it is necessary to pass through the vibration isolating members 0 and 0 in stages over a required distance, the vibrations are extremely effectively damped and become minute vibrations. Thereby, it is possible to prevent adverse effects on the worker during the mowing work.

When the handle 3 is gripped with both hands and swung in a fan-like manner to cut the grass, the transmission shaft outer tube 12 needs to be repeatedly rotated in both directions as shown by the arrow 38. The transmission off-axis tube 12 slides on the contact surface with the outer tube holder 24 and the washer 32, allowing for good rotation. Furthermore, since the first and second members 18 and 20 constitute an effective vibration isolation mechanism, almost no vibration is transmitted to the handle 3.

Furthermore, since most of the vibration of the protruding end 8a of the clutch case 8 is absorbed by the first member 18,
Even when the operator grips the outer surface of the connecting fitting 21, the vibration of the engine 4 is hardly transmitted to the operator. Furthermore, since the fastening tool that fastens the connecting fitting 21 is located on the non-vibration side, there is no risk that the fastening tool will unnecessarily loosen and fall off. Thereby, the connection part 16 can be constructed firmly and its service life can be extended.

As is clear from the above detailed explanation, according to the present invention, the first member made of a vibration isolating material is fitted onto the protruding end of the clutch case, and the flange is made to face the protruding end of the clutch case, and the transmission A second member made of a vibration isolating material is fitted onto the rear end of the off-axis tube,
In addition, by connecting the first member and the second member from the outside using a connecting fitting to prevent vibrations, engine vibrations are dispersed, and the first member
The member and the second member provide effective vibration isolation by gradually attenuating the vibration over a required distance, preventing any negative impact on the worker, and simplifying the structure. By allowing rotation of the transmission off-axis tube, operability can be improved, and work efficiency of brush cutting work can be improved.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a perspective view of a brush cutter, FIG. 2 is an enlarged sectional view of the grip, and FIG. 3 is a sectional view taken along the line - - in FIG. 2. Explanation of main symbols: 2 is the brush cutter, 8 is the clutch case, 8a is the protruding end, 12 is the transmission off-axis tube, 1
2a is a rear end, 12f is a flange, 18 is a first member, 20 is a second member, and 21 is a connecting fitting.

Claims (1)

[Scope of utility model registration request] A first member made of a vibration isolating material is fitted onto the protruding end of the clutch case, a flange is formed at the rearmost edge of the transmission shaft outer tube, and the flange is opposed to the protruding end of the clutch case. At the same time, a second member made of a vibration isolating material is externally fitted onto the rear end of the transmission off-axis tube so that the transmission off-axis tube can rotate, and the first member and the second member are held from the outside. A vibration isolating device for a brush cutter, characterized in that both members are connected by a connecting fitting for vibration isolation.