JPS5932494Y2 - Circular saw - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a circular saw, and more particularly to a circular saw that reduces rotational noise generation when not cutting, that is, when spinning idle.

Circular saws that are widely used today generate more noise as their rotational speed increases.

This seems to be because the natural frequency of the circular saw resonates with other rotating systems as the rotational speed increases, generating peak noise.

For this reason, circular saws often produce a sharp metallic sound, especially when idling.

This causes industrial accidents and even noise pollution.

The present invention aims to reduce such noise.

FIG. 1 shows an embodiment of the present invention.

In the figure, 10 is a circular saw which is known per se.

The base metal part 12 of the circular saw 10 has, for example, two grooves 14 and 16.
is provided concentrically with the mounting hole 18 in the center of the circular saw.

The depth of the grooves 14 and 16 is, for example, approximately 115 times the thickness of the alloy portion 12, and the width thereof is approximately the same as the thickness of the alloy portion 12.

In other words, in the case of a circular saw where the alloy part has a thickness of 2 mm, the depth of the groove is 0.
4 am and approximately 2 am wide.

However, this is not a limitation. Within the groove 14.16, small holes 20.22 are provided at equal intervals and spaced apart from each other by a half pinch.

However, a synthetic resin 24, preferably an epoxy resin or synthetic rubber, is buried in the grooves 14, 16 to such an extent that it does not protrude above the alloy surface.

The small holes 20 and 22 are grooves 14 provided on both sides of the saw 10.
The resins embedded in the saw are connected to each other to increase the adhesion of the resin to the saw.

We will discuss the experimental results of comparing a circular saw machined with the structure of the present invention with an unprocessed circular saw.

The selected circular saw has an outer diameter of 305 mm, a number of blades of 100, a blade thickness of 2.8 mm, and an alloy portion thickness of 2 my.

The circular saw was rotated at a predetermined number of revolutions, and the Aiwa condenser microphone CM-1oo was cut 70 mm from the center of the shaft.
440m above the saw alloy surface to the left of the rotation axis
I fixed it on a tripod at a position 585mm above the ground, and attached an indicator sound level meter (Rion NA-09) and 1/3
The results of frequency analysis using an octave analyzer are shown in Table 1 below.

Next, two grooves with a depth of 0.4 mm and a width of 2 mm were made on a similar circular saw.

The radius to the center of the inner groove was 114 m4, and the radius to the center of the outer groove was 121 mm. There were five small holes in the groove, and epoxy adhesive was embedded in the groove.

The results of observation using a similar method using a circular saw embodying the present invention are shown in Table 2 below.

It should be noted that FIG. 3 is a graph showing the noise generation state of the known circular saw (Table 1) and the circular saw of the present invention (Table 2).

As is clear from the above experimental results, the circular saw of the present invention significantly limits noise generation compared to known circular saws, and the associated occupational accidents are significantly reduced. .

The present invention is not limited to the form described above, and the shape, number of grooves, etc. of the grooves can be changed as appropriate, and the effect can be expected even if the grooves are arranged only on one side of the alloy. It is.

This is done by attaching a substance such as epoxy resin that has a Young's modulus different from the Young's modulus of steel, which is the material of the circular saw, to attenuate, eliminate, or shift the resonant frequency of the circular saw. The peak sound level is lowered by lowering the resonance or resonant region.

[Brief explanation of the drawing]

Figure 1 is a plan view of the circular saw of the present invention, and Figure 2 is the same as in Figure 1.
① View from the arrow, FIG. 3 is a graph comparing the amount of noise generated between the circular saw of the present invention and a known circular saw. Explanation of symbols, 10: Circular saw, 12: Base metal part, 14゜16:
Groove, 24: synthetic resin.

Claims (3)

[Scope of utility model registration request] (1) A circular saw having a steel base metal part, between a central mounting hole and a peripheral cutting blade, forming a groove concentric with the mounting hole on both sides of the alloy part, A small hole penetrating from one side of the alloy part to the other side is provided in the groove, and a synthetic resin is embedded in the groove so as to be substantially flush with the surface of the base metal part, and a synthetic resin is inserted through the small hole. A circular saw that connects the synthetic resins on both sides with each other, thereby preventing these synthetic resins from separating from the groove. (2) The circular saw according to claim 1, wherein the synthetic resin is an epoxy resin. (3) Utility model registration request where the synthetic resin is synthetic rubber 0]
A circular saw according to item 1 or 2 of the scope.