JPH02256500A - Sound insulating method for water jet cutting - Google Patents

Abstract

PURPOSE:To effectively prevent noise propagation without damaging a cover by arranging a damping material irregularly reflecting a jet stream in the sound insulating cover. CONSTITUTION:The opening section 11 of a sound insulating cover 1 opened only on one side is hermetically fitted to the rear face of an object to be cut A. V-shaped angle steel plates D each opened with a window D2 are replaceably planted in this sound insulating cover 1. A water jet penetrating the rear face of the object to be cut A is irregularly reflected on ridges of the angle steel plates D, the speed of the jet stream is quickly reduced, thus high-frequency noise is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention is directed to reducing high-frequency noise generated during water jet cutting using ultra-high pressure water and abrasive material. There is a cutting method that uses a water jet to cut concrete or steel by ejecting water from a small water jet hole.

When cutting with this water jet, the speed of the ultra-high pressure water ejected from the ejection hole reaches the sonic speed range, which generates high-frequency noise.

High-frequency sound is generated not only by the jet stream before cutting, but also by the jet stream ejected onto the back surface after cutting.

In other words, as shown in FIG. 3, the jet flow J that has passed through the object A has not completely exhausted its cutting ability.
It is also ejected to the back side of the object to be cut A as an ultra-high-pressure, ultra-high-speed jet.

Therefore, the jet flow J after cutting is also a source of high frequency noise.

The longer the length of the jet J, which is ejected from the back surface and has cutting ability, the louder the noise will be.

In order to prevent the propagation of noise caused by ultra-high pressure water, a cover is installed around the cutting surface to prevent the propagation of noise. A cover is also installed on the back of the cut object.

<Problems to be Solved by the Present Invention> The following problems exist in the above known methods.

(a) The jet stream does not completely lose its cutting ability after cutting the object.

Therefore, if the cover is positioned close to the cutting surface, the cover will also be cut.

In order to prevent the cover from being cut and to soundproof it,
The depth of the cover must be designed to be greater than the distance at which the cutting ability of the jet stream is attenuated.

However, with such a distance, a large space is created between the cutting surface and the cutting surface, making it difficult to completely contain the noise.

<Exposure> A cover with a distance +IIL at which the cutting ability of the jet stream is attenuated has a thick outer dimension (and the cover becomes large).

Therefore, it is very inconvenient to handle the cutting part in order to frequently change its position and follow the cutting part for sound insulation.

<Objective of the present invention> The present invention was made in order to improve the above-mentioned problems, and provides soundproofing for water jet cutting that can effectively prevent noise propagation without damaging the cover. The purpose is to provide a method.

<Configuration of the present invention> Next, one embodiment of the present invention will be described.

<A> Soundproof cover The soundproof cover 1 consists of a surrounding wall surface and a bottom plate 16,
-It is a rectangular box with only one side open.

Then, around the opening 11, a flange 1 is provided outwardly.
2 is provided protruding like a brim.

This flange 12 is used when attaching the soundproof cover 1 to the object A to be cut.

The depth from the opening 11 to the bottom plate 16 is configured to be shorter than the distance at which the jet flow that penetrates the object A completely loses its cutting ability.

The bottom plate 16 is provided with a discharge hole 17 for discharging abrasive material, water, and the like.

During use, the cover 1 is attached to cover the cutting line on the back side of the object to be cut, but it is also conceivable to interpose a gasket P between the flange 12 and the object A to be cut.

<Exposure> Damping material A damping material is attached inside the soundproof cover 1 to damp the pressure of the jet flow.

In the present invention, an angle-shaped damping beam is particularly used, and this damping beam is constituted by a long angle-shaped steel plate having a linear cross section.

This angle-shaped steel plate has notches provided at the corners of the V-shaped cross section at uniform intervals in the longitudinal direction, and these are used as window portions D2.

<C> Incorporation into the protective cover The hem portions Di on both sides of this chevron-shaped damping material are attached to the wall plate or bottom plate 16 of the protective cover 1 so as to be replaceable.

Therefore, the shape is such that the top portion of the single-character shape is exposed toward the opening 11 .

The chevron-shaped damping material is not just one piece (by stacking many pieces,
Arrange the mountain peaks in the same direction.

In this case, the window portions D2 of the upper and lower chevron-shaped damping members are arranged with their positions slightly shifted.

Furthermore, the mountaintop is positioned so that the jet stream collides with its corner.

In addition, it is also possible to attach the mountain peak not to face the opening 11 but to face the bottom 16 side.

In that case as well, the jet stream is arranged so that it impinges on the corner from the inside.

<Operation> (Fig. 2) A jet stream injected linearly into the soundproof cover 1 from the opening 11 of the soundproof cover 1 collides with the top of the mountain-shaped damping material.

The jet stream then changes its angle and is thrown off to the side. The next jet stream then collides with the other, consuming energy from each other and causing a sudden drop in speed.

The jet flow that has flown into the window portion D2 collides with the peak of the mountain-shaped damping material below and similarly consumes energy.

In this way, the jet stream repeatedly reflects diffusely within the soundproof cover 1, the cutting ability of the jet stream is instantly attenuated, and the sound is also reduced.

<Effects of the Present Invention> Since the present invention has the above structure, the following effects can be achieved.

<A> A damping material that diffusely reflects the jet stream is placed inside the soundproof cover.

Therefore, even after the cutting is finished, the cutting ability is still maintained, and the speed of the jet flow that generates high-frequency sound due to high speed can be rapidly reduced, thereby reducing noise due to high frequency.

<Exposure> The damping material is replaceably installed inside the soundproof cover.

Therefore, even if wear or damage occurs, the damping material can be replaced with new damping material one by one, and the protective function of the soundproof cover can be maintained for a long time.

<C> The jet flow having cutting ability rapidly attenuates its speed near the back surface and does not reach the bottom surface of the soundproof cover.

Therefore, the soundproof cover has sufficient durability.

(2) Since the damping material is located between the back surface of the object to be cut and the bottom surface of the soundproof cover, the depth of the soundproof cover can be made shallow, and the soundproof device itself can be downsized.

Therefore, even at a cutting site with poor footing, the soundproof cover can be easily moved and work can be carried out quickly.

<E> The soundproof cover itself has a soundproofing effect and also has the effect of preventing abrasive materials etc. from scattering during cutting.

[Brief explanation of drawings]

Figure 1: An explanatory diagram of an embodiment of the soundproof cover used in the soundproofing method of the present invention. Figure 2: An explanatory diagram of the state of use. Figure 3: An explanatory diagram of the state of needle cutting.

Claims (1)

[Claims] ￥ In the case of performing cutting work by spraying a water jet from the surface of an object to be cut, a soundproof cover is arranged on the back side of the object for soundproofing, ￥ A soundproof cover with an opening on only one side The opening is attached in a sealed state to the back of the object to be cut, and inside this soundproof cover, an angle-shaped steel plate with a V-shaped cross section and a window is installed so that it can be replaced. The top of the mountain connects the water jet that penetrates the back side of the object to be cut.
Soundproofing method for water jet cutting performed by diffused reflection