JPS6154488B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an explosion chamber equipped with a noise reduction structure that can effectively reduce the explosion noise generated when explosives or the like are detonated in the explosion chamber.

In recent years, the explosion of explosives has been used to perform processing such as forming and joining metals, as well as phase transformation and sintering of solid materials such as synthetic diamonds and high-pressure phase boron nitride. Explosive experiments such as tests have been carried out.

On the other hand, from the standpoint of protecting the living environment, efforts have recently been made to prevent various noises and vibrations, and many silencers have been developed to reduce the explosion noise of explosives. However, the explosion sound of explosives was extremely powerful, and it was extremely difficult to muffle it efficiently.

Measures to reduce sound include (1) reducing vibration, which is the source of sound, and (2) using vibration isolation to prevent secondary sound from occurring due to vibration propagating to other objects and causing them to vibrate. (3) Blocking the airborne propagation of sound (4) Reducing the sound pressure through expansion, interference, and absorption of airborne sound.

In order to muffle the sound of an explosion, the first step was to block the airborne propagation of the sound, by conducting the explosion in an explosion chamber or dome, and using these structures to block the direct airborne propagation of the explosion sound. , the propagation of sound from the open parts could not be prevented.

For this reason, there have been cases in which explosions have been carried out in sealed explosion chambers, but the internal pressure exerted by the resulting gas caused the explosion chamber to collapse, resulting in a shortened lifespan.

Therefore, as shown in Fig. 1, an explosion chamber 1 is considered, in which a cover 4 with a foundation 5 attached to it is installed on the ground 9, and a muffling tube 2 is attached. A mechanism was installed to reduce the explosion sound pressure caused by the explosion of Explosive 3.

However, with a device that attaches a silencer to the explosion chamber,
It was not effective unless the muffler was made longer, and in general it could not be said that it was sufficiently effective.

In order to further increase the noise reduction effect, the present invention provides an explosion chamber with a hollow double wall or multiple hollow walls, with openings provided in the inner wall, outer wall, or intermediate wall, and the openings in each adjacent wall are separated by the maximum distance. This is the first invention, and the second invention is an explosion chamber in which a bar is installed between the walls, and a sound absorbing material is attached to the bar and/or the wall. This explosion chamber was designated as the third invention. According to the devices of these inventions, not only the silencing effect is improved;
It does not require a long muffling tube, is compact, and has a long service life.

The apparatus of the present invention will be described in more detail as follows.

The first invention is as follows. The entire surface or most of the surface of the enclosure constructed surrounding the explosion point shall be a hollow double wall or three or more hollow multiple walls. The rectangular body may have a polygonal, circular, truncated cone, or truncated pyramid shape with a normal ceiling, or a hemispherical or polyhedral shape without a ceiling.

In the case of a hollow double wall, an inter-wall space is provided between the inner wall and the outer wall, and an inner wall opening and an outer wall opening are provided in the inner and outer walls, respectively, but the inner wall opening is located near the bottom of the side, or on the ceiling or ceiling. Any nearby part is fine, but if an opening is provided in the outer wall, it must be provided in the outer wall as far away as possible from the inner wall opening. The maximum distance means, for example, in the case of a double wall, when the inner wall opening is located near the bottom of the side surface, the outer wall opening is located near the ceiling. This refers to the maximum distance between Further, the shape of the opening in each wall may be any shape such as a strip, a rectangle, a circle, or an oval. For example, when the inner wall opening is provided in a strip shape at the bottom of the inner wall, the outer wall opening is provided in a strip shape near the top of the outer wall. As a result, the explosion generated gas flows from the explosion chamber through the inner wall opening, via the inter-wall space, and out of the outer wall opening to the outside world.

In addition, in the case of a hollow multi-walled enclosure with three or more layers, it consists of an inner wall with an opening similar to that of a hollow double wall, one or more intermediate walls, and an outer wall. Provided at the hem, top, or in between, the intermediate wall opening adjacent to this is provided at a position farther from the inner wall opening, and successively extends to the outer wall so that the openings in the adjacent walls mutually maximize. It shall be installed so that it melts. The explosion chamber thus provided is the device of the first invention.

Next, the second invention will be described. If baffle plates are erected on the wall between the openings in each wall of the device of the first invention, the sound can be further muted. A bridge is created between both walls at intervals, and another row of boards is created above and below that row of boards, with the bridging boards shifted in position, to prevent the explosion-produced gas or sound waves from traveling straight. The latter method of installing baffle plates has the effect of making the cover stronger because the baffle plates connect the walls.

Next, the apparatus of the third invention is the apparatus of the second invention, in which a sound absorbing material is pasted on the surface of the baffle plate and/or the wall surface. This has the effect that the explosion generated gas or sound waves are absorbed by the sound absorbing material.

Next, the embodiment shown in the drawings will be explained.

FIG. 2 is a cross-sectional view of an explosion chamber equipped with a noise reduction structure according to the first embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along the line -' of FIG. It is. In FIGS. 2 and 3, the explosion chamber 1 is approximately in the shape of a truncated quadrangular pyramid, and is comprised of an inner wall 6, an outer wall 7, and a ceiling 8, and is mostly covered by a hollow double-walled shell 4. An inner wall opening 10 is formed at the bottom of the inner wall 6, and the inter-wall space 1 is connected from the inside of the explosion chamber 1.
It serves as a passage for the explosion gas to 1. Further, an outer wall opening 12 is provided near the top of the outer wall 7, and serves as a passage for the flow of explosion gas between the interwall space 11 and the outside world. Also, the outer surface of the opposing inner wall 6 and the outer wall 7
A baffle plate 18 is provided between the inner surface and the inner surface. Note 5
is the foundation and 9 is the ground. Further, the outer surface of the inner wall 6, the inner surface of the outer wall 7, and the surface of the baffle plate 18 are covered with sound absorbing material 1.
4 is attached. Normally, the explosion takes place at the explosive charge 3 placed near the center of the bottom of the explosion chamber 1, which serves as the detonation point.

The effects of noise reduction in the explosion chamber shown in FIG. 2 are explained as follows.

When the explosive 3 explodes, the explosion impulse pressure is transmitted and the explosion generated gas flows, sometimes becoming sound waves, which collide with the inner wall 6 and enter the rear inter-wall space 11 attenuated by the blocking effect of the inner wall 6. It propagates as a sound wave and impinges on the outer wall 7, where it is also attenuated by the sound insulation effect. Sound insulation effect reduces volume TL
(dB), and the reduced volume is TL=18 log・M−
44 (: frequency (Hz), M: areal density (Kg/m ² )). Heavy walls have a greater sound insulation effect.

On the other hand, the explosion gas emitted from the explosive 3 flows all over the inner surface of the inner wall 6 in the explosion chamber 1,
Since it is blocked by the inner wall 6, it enters the inter-wall space 11 through the inner wall opening 10 at the bottom of the inner wall 6, passes through the inter-wall space 11, and the gas pressure or sound pressure is reduced by the baffle plate 13, and at the same time the sound absorbing material 14, the sound is also absorbed and goes outside through the outer wall opening 12, so the sound is extremely low.

In addition, in order to constitute a double wall, an inner wall 6 and an outer wall 7 are
The structural material that supports the structure also serves as a baffle plate. Further, as the sound absorbing material 14, glass fiber, rock wool, sound absorbing texture, etc. are used.

Next, FIG. 4 is a sectional view of a hollow triple-walled explosion chamber according to a second embodiment of the present invention. Note that this embodiment is an embodiment of the second invention. In FIG. 4, 1 is an explosion chamber, 3 is an explosive, 5 is a foundation, and 9 is the ground. An inner wall opening 10 is provided at the base of the inner wall 6, and an outer wall 7 is located outside the shelter 4. There is an intermediate wall 15 between the outer wall 7 and an outer wall opening 16 at the bottom of the outer wall 7. There is an inter-wall space 1 between the inner wall 6 and the intermediate wall 15 and between the intermediate wall 15 and the outer wall 7.
7, and in the inter-wall space 17 there are an inner wall 6 and an intermediate wall 1.
baffle plates 18 erected alternately from intermediate wall 15 and outer wall 7; and baffle plates 1 alternately erected from intermediate wall 15 and outer wall 7;
8, 19 is a partition wall that partitions the left and right inter-wall spaces 17, and 20 is an intermediate wall opening.

In the device shown in FIG. 4, when the explosive 3 explodes, the explosion-produced gas flow or sound wave collides with the inner wall 6, is attenuated by the sound insulation effect, enters the interwall space 17, becomes a sound wave, and collides with the intermediate wall 15. However, the sound waves are attenuated there by the sound insulation effect, and furthermore, the sound waves pass through the inter-wall space 17, collide with the outer wall 7, and are further attenuated. On the other hand, explosion generated gas or sound waves enter the inter-wall space 17 from the inner wall opening 10, are attenuated by the baffle plate 18, are reflected by the partition wall 19, pass through the inter-wall space 17, and exit to the outside world from the outer wall opening 16, so that they are significantly attenuated. Ru.

Although the explosion chambers shown in FIGS. 2 and 4 are shown as embodiments, in the explosion chamber of FIG. 2, baffle plates 18 installed on various walls of the explosion chamber of FIG. It may be used instead of 13. In this manner, various settings are made in the apparatus of the present invention.

Next, the effects of the present invention will be described.

The silencing effect of the device of the invention takes place in two sound propagation paths: one by direct sound insulation through the walls, and the other by reducing the gas pressure of the explosion gas stream or the sound pressure of the sound waves. reduction through expansion, interference, and absorption. Generally the first
As described in the description of the embodiment, even if the total thickness is the same, the sound insulation effect will be greater if a number of thinner walls are provided. In addition, the explosion-produced gas flow or sound waves enter through the inner wall opening, pass through a long space between walls, and finally eject outside the explosion chamber from the outer wall opening, so the gas pressure or sound pressure decreases due to expansion, interference, and absorption. Therefore, the sound becomes smaller.
Even with the installation of baffles, gas pressure and sound pressure still decrease, and sound is also absorbed by the sound-absorbing material attached to the surface of the wall and/or the surface of the baffle, further reducing the sound pressure. . In this way, two silencing functions can be achieved at the same time.

Secondly, since there is a discharge passage for the explosion gas, it is possible to prevent damage to the explosion chamber due to internal pressure as in a closed explosion chamber, thereby extending the life of the explosion chamber. On the other hand, there is no need to provide a duct-like or chimney-like muffling cylinder as in the conventional case, and the structure of the explosion chamber can be simplified.

Furthermore, as already mentioned, in the same sense that the structural material serves as a baffle plate, the explosion chamber can be reinforced by using the baffle plate as a structural material.

Furthermore, if the metal enclosing the explosive or objects near the explosive are scattered at high speed during an explosion, the double-walled wall or more has greater resistance to penetration, which helps improve safety.

In the explosion chamber according to the present invention, methods for further increasing the silencing effect include enclosing the outside of the explosion chamber with other structures to further enhance the silencing effect, or coating the outer surface of the outer wall with small particles such as sand. There is.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional explanatory view of an explosion chamber equipped with a conventional muffler, Fig. 2 is a cross-sectional view of an explosion chamber according to the first embodiment of the present invention, and Fig. 3 is a cross-sectional view of the explosion chamber equipped with a conventional muffler.
4 is a sectional view of an explosion chamber according to a second embodiment of the present invention. 1: explosion chamber, 3: explosives, 4: covert body, 6: inner wall,
7: outer wall, 10: inner wall opening, 12, 16: outer wall opening, 13, 18: baffle plate, 15: intermediate wall.

Claims (1)

[Scope of Claims] 1. All or most of the shelter constructed surrounding the explosion point is made of a hollow double wall or three or more hollow walls, and the inner wall is provided with an opening that leads from the explosion chamber to the space between the walls, An opening leading from the interwall space to the outside of the explosion chamber shall be provided in the outer wall, and in the case of the hollow multilayer wall, an opening shall be provided in the intermediate wall, and the openings in adjacent walls shall be spaced apart from each other by the maximum distance. An explosion chamber equipped with a noise-absorbing structure. 2 All or most of the shelter constructed surrounding the explosion point shall be a hollow double wall or three or more hollow walls, with an opening leading from the explosion chamber to the inter-wall space in the inner wall, and an inter-wall space in the outer wall. An opening leading from the explosion chamber to the outside of the explosion chamber is provided, and in the case of the hollow multi-layered wall, an opening is provided in the intermediate wall, and the openings in each adjacent wall are arranged at the maximum distance from each other, and there is no space in the inter-wall space. An explosion chamber equipped with a noise-absorbing structure characterized by the installation of a barrier plate that is erected from each wall and prevents the straight propagation of explosion generated gas or sound waves. 3 All or most of the enclosure constructed surrounding the explosion point shall be a hollow double wall or three or more hollow walls, with an opening leading from the explosion chamber to the inter-wall space in the inner wall, and an inter-wall space in the outer wall. An opening leading from the explosion chamber to the outside of the explosion chamber is provided, and in the case of the hollow multi-layered wall, an opening is provided in the intermediate wall, and the openings in each adjacent wall are arranged at the maximum distance from each other, and there is no space in the inter-wall space. An explosion chamber equipped with a sound-absorbing structure, characterized in that a barrier plate is installed from each wall to prevent the explosion gas or sound waves from going straight, and a sound-absorbing material is attached to the surface of the barrier plate and/or the wall surface.