JPS5946750B2 - Anti-vibration handle device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vibration-isolating bundle device, and in particular, it is installed in vibrating machines such as hand-held power tools such as brush cutters, compressed air tools, and motorcycles, and is used to prevent vibrations generated in these machines. The present invention relates to a vibration-isolating handle device that can sufficiently prevent vibrations from being transmitted to a gripping member that is a bundle part, improve the operability of a vibrating machine, and can be made small and lightweight.

Conventionally, as a vibration isolation measure for hand-held tools such as brush cutters and vibrating machines such as motorcycles, vibration isolating rubber has been interposed between the vibration source of the vibrating machine and the bundle, or a vibration absorber has been installed. I was using it.

However, when anti-vibration rubber is used, a force proportional to the vibration speed is transmitted to the bundle, making it difficult to block harmful vibrations that cause occupational accidents such as white wax, and making it difficult to control the bundle. Vibrating tools that are soft will cause wobbling.

In addition, in the case of a vibration absorber, in order to increase the vibration isolation effect,
There is a problem in that the weight of the vibration absorber must be increased, and the workability and operability of the vibrating tool are reduced.

The present invention has been devised to effectively solve the problems of the conventional Hiko as described above.

The purpose of this invention is to sufficiently isolate harmful vibrations that occur in bundles of hand-held vibrating tools such as brush cutters and vibrating machines such as motorcycles, and to improve the operability of vibrating machines. The object of the present invention is to provide a vibration-proof bundle device that can be manufactured to be small and lightweight.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a vibration source that generates harmful vibrations, such as the main body or casing of a brush cutter, electric grinder, or the like, or the body of a motorcycle.

A rod-shaped body 2 made of steel and having a circular cross section is provided extending from the vibration source 1 in a cantilevered manner.

The fixed end of the rod-shaped body 2 is provided with a male thread 2a.
The fixed end of the rod-shaped body 2 is inserted into the vibration source 1 by passing through the screw hole of the connecting part 3 fixed by welding or the like to the vibration source 1, and further screwing the tip of the fixed end into the vibration source 1. Fixed.

A first mass body 4 is provided at the free end of the rod-shaped body 2 .

The first mass body 4 is provided with a screw hole into which the male thread 2b provided at the free end of the rod-shaped body 2 can be screwed. The mass body 4 can be moved in the axial direction of the rod-shaped body 2.

Further, a rod-shaped body 2 is provided between the first mass body 4 and the connecting portion 3.
A cylindrical grip member 5 is provided so as to be spaced apart from and cover the outside of the grip member.

A coil spring 6 is connected between the connecting portion 3 and the left end 5a of the grip member 5, and a coil spring 6 is connected between the first mass body 4 and the right end 5a of the grip member 5.
A coil spring 7 is provided between each of the coil springs 7 and b.

The coil springs 6 and 7 have the same strength, the grip member 5 is supported by the elastic force of the coil springs 6 and 7, and the grip member 5 is connected to the rod-shaped body 2, the first mass body 4 and the connection There is no direct contact with the portion 3, and vibrations are transmitted and received between them and the grip member 5 via the coil springs 6 and 7.

Note that 3 a 24 at 5 ct 5 d is the spring receiver.

On the outer periphery of the left end 5a and right end 5b of the grip member 5,
a second mass body 8 having the same mass and having an annular shape;
9 are provided respectively.

In order to allow the second mass bodies 8 and 9 to slide along the axial direction of the gripping member 5, external threads 5e and 5f are provided on the outer circumferential surfaces of the left end portion 5a and the right end portion 5b. The inner circumferential surfaces of the mass bodies 8 and 9 of No. 2 are provided with female threads 8a and 9a, respectively, which engage with the male threads 5e and 5f.

Further, the second mass bodies 8 and 9 are each provided with a set screw 10111 for fixing them to the grip member 5.

Next, the operation of this embodiment will be described.

The harmful original vibration from the vibration source 1 is transmitted to the connecting part 3 and the rod-shaped body 2.
is transmitted to the fixed end of the vibration source, and vibrates with the same phase and frequency as the original vibration.

Vibration energy (kinetic energy) transmitted from the vibration source 1 to the connecting portion 3 and the fixed end of the rod-shaped body 2 is divided into two and transmitted via the coil spring 6 and the rod-shaped body 2.

However, since the rod-shaped body 2 has considerably greater rigidity than the coil spring 6, most of the vibration energy is transmitted to the first mass body 4 via the rod-shaped body 2, and the remaining part of the vibration energy is transmitted to the first mass body 4 through the rod-shaped body 2. is transmitted to the left end portion 5a of the grip member 5 via the coil spring 6.

The first mass body 4 is vibrated by the vibration transmitted via the rod-shaped body 2 in substantially the same phase and frequency as the original vibration.

The vibrations of the first mass body 4 are transmitted to the right end portion 5b of the grip member 5 via the coil spring 7 in a significantly attenuated manner, and further transmitted to the second mass body 9.

Furthermore, the vibrations transmitted to the left end portion 5a via the coil spring 6 are transmitted to the second mass body 8.

By the way, here, when the second mass bodies 8 and 9 are screwed and installed at appropriate positions between the left end 5a and the right end 5b, the second mass body 9 or the gripping member near it 5, vibration nodes can be formed, and the amplitude of the second mass body 9 can be made extremely small.

This will be explained using the schematic diagram shown in FIG.

In the figure, 20 is an elongated rod made of metal or the like, and the rod 20
Weights 21 and 22 are respectively attached to the center and tip of the tube.

When the base end 20a of this rod 20 is vibrated from side to side, this vibration is transmitted to the weights 21 and 22 through the rod 20, and the weights 11 and 22 vibrate.

However, if the mass of the weights 21 and 22, the mounting position of the weights 21 and 22 on the rod 20, and the elastic modulus and thickness of the rod 20 are appropriately selected, the weights 22 and 22 can be fixed as shown in the figure.
It is possible to create a state of vibration in which there is almost no vibration.

In other words, the weight 21 vibrates at the same frequency and phase as the base end 20a, and the weight 22 lags behind the vibration of the weight 21 and vibrates at the same frequency and in the opposite phase as the weight 21. The vibration transmitted from the seat 21 to the weight 22 is significantly reduced.
will vibrate with extremely small amplitude.

Comparing the vibration system shown in FIG. 2 with the vibration system of the above embodiment, the weight 21 is attached to the first mass body 4, and the weight 22 is attached to the second mass body 4.
Further, the portion from the base end 20a of the rod 20 to the weight 21 corresponds to the rod-shaped body 2, and the portion from the weight 21 to the weight 22 of the rod 20 corresponds to the coil spring 7. It is thought that

That is, most of the vibration energy of the original vibration from the vibration source 1 is transmitted to the first mass body 4 via the rod-shaped body 2, and the first mass body 4 is excited.

At this time, the vibration energy of the original vibration is mainly caused by the rod-shaped body 2,
It is dissipated as thermal energy (heat generation) caused by internal strain within the first mass body 4 and the coil spring 7.

The second mass body 9 vibrates at almost the opposite phase and the same frequency as the first mass body 4, and there are vibration nodes in the first mass body 9 and the grip member 5 in its vicinity. The formed second mass 9 vibrates with a very small amplitude.

On the other hand, a small remaining portion of the vibration energy of the original vibration is transmitted to the second mass body 8 and the left end portion 5a via the coil spring 6, but this vibration is suppressed by the mass of the second mass body 8. Significantly attenuated.

Therefore, the original vibration from the vibration source 1 is hardly transmitted to the grip part 5g of the middle man of the vibration member 5 between the second mass bodies 8 and 9, and the operator The vibrations transmitted to the hand of the user are significantly weaker than the original vibrations.

Further, since a soft elastic member such as vibration-proof rubber is not used, a vibrating tool such as an electric drill does not wobble, and the tool can be operated accurately.

Furthermore, since a method is adopted in which vibration nodes are formed in the device and the grip portion is attached to these nodes, the device can be made much lighter and smaller than conventional devices.

In the above embodiment, in order to form a vibration node in the second mass body 9 or the grip member 5 in the vicinity thereof, the second
The mass body 9 is adjusted by moving it along the grip member 5, but the first or second mass body 4.9 is formed by a plurality of divided pieces, and the mass can be increased or decreased by attaching and detaching the divided pieces. It may also be possible to make the adjustment by

Further, since the second mass body 8 suppresses the vibration from the coil spring 6 by its mass, the spring receiver where the vibration is transmitted from the coil spring 6 to the grip member 5 is located outside the portion 5c, as shown in FIG. If installed nearby, the vibration suppression effect will be great.

In the above embodiment, the rod-like body 2 is a round rod having the same diameter over its entire length, but the flexibility of the free end side of the rod-like body 2 is increased to violently vibrate the first mass body 4 to dissipate energy. In order to achieve this, as shown in FIG. 3, it is formed into a tapered shape that gradually decreases in diameter toward the free end, or as shown in FIG. You can change it to what you have installed.

Further, instead of the coil springs 62 and 7, leaf springs or the like may be used.

Furthermore, the connecting part 3 is omitted, and the vibration source 1 is made only by the rod-shaped body 2.
It may be connected to

Alternatively, the grip member 5 may be extended to cover the outside of the first mass body 4.

5 to 7 show the results of vibration experiments conducted by attaching the bundle device of the above-described embodiment according to the present invention and a conventional standard bundle to a commercially available brush cutter.

FIG. 5 shows the acceleration of the original vibration of the vibration source at the bundle attachment point.

Further, FIG. 6 shows the acceleration of vibration transmitted to the grip of the conventional standard bundle, and FIG. 7 shows the acceleration of vibration transmitted to the grip of the bundle of the present invention. There is.

In FIGS. 5, 6, and 7, the horizontal axis is time, the vertical axis is acceleration, and g is gravitational acceleration.

As shown in the figure, the original vibration is significantly attenuated by the bundle of the present invention, and the remarkable vibration damping effect of the present invention is recognized.

Although FIGS. 5, 6, and 7 show the acceleration of vibration in the vertical direction, the bundle of the present invention has vibration acceleration in the horizontal direction (radial direction and horizontal direction of the grip member 5). It has been confirmed that similar vibration damping effects can be obtained for vibrations in the forward and backward motion directions (axial direction of the rod-shaped body 2), and it is also effective against original vibrations in which vibrations in these three directions are complexly overlapped. A vibration-proofing effect can be obtained.

As is clear from the above explanation, according to the present invention, it is possible to almost completely isolate the harmful vibrations that cause white wax, etc., and furthermore, since no anti-vibration rubber is used, the operability of vibrating tools, etc. is improved. Moreover, it can exhibit excellent effects such as being lightweight and small in size.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the device according to the present invention;
FIG. 2 is a schematic diagram for explaining the anti-vibration effect of the present invention, FIG. 3 is a front view showing another example of a rod-shaped body, FIG. 4 is a front view showing another example of a rod-shaped body, and FIG. The figure is a graph showing the acceleration of the original vibration at the bundle attachment part of a commercially available brush cutter.
FIG. 7 is a graph showing the acceleration of vibration transmitted to the grip portion of each bundle when a conventional standard bundle and the bundle of the present invention are attached to the same brush cutter. In the figure, 1 is a vibration source, 2 is a rod-shaped body, 4 is a first mass body, 5
is a grip member, 6 and 7 are elastic members (coil springs), 8 and 9
is the second mass body.

Claims (1)

[Claims] 1. A rod-shaped body connected to a vibration source and extending from the vibration source;
a first mass body provided at the free end of the rod-shaped body; a grip member provided to cover the rod-shaped body while being spaced therefrom; the grip member, the first mass body, and vibrations. A vibration-proofing device characterized by comprising: resilient members that are respectively interposed between a source and resiliently support a gripping member; and second mass bodies that are respectively provided at both ends of the gripping member. Bundle device.