JPS5815614Y2 - Silencer - Google Patents

Description

[Detailed description of the invention] The present invention is a muffling device that is connected to the discharge port of a vacuum pump or similar device built into various machines, and effectively muffles sound waves that enter the discharged air. Regarding.

Reducing the noise emitted from the discharge ports of vacuum pumps and other devices as much as possible is an essential issue from the standpoint of pollution prevention, work environment, and work efficiency, and research on this topic is being actively conducted. It is well known that there are.

This type of silencer, which is usually called a silencer, can be roughly divided into the so-called ``resonance type,'' which utilizes the phenomenon of resonance attenuation, and the so-called ``expansion type,'' which has an expansion chamber, and further attenuates and eliminates sounds with a wide range of frequencies. Therefore, there are devices that combine these types or add sound-absorbing materials, but these conventional devices basically attenuate the sounds by causing them to interfere with each other, or by diffusing or absorbing them.

The present invention also applies the above principle, but instead of simply interfering with and diffusing sound as in the past, it temporarily confines the air accompanied by noise from the discharge port in a sealed chamber. The feature is that noise is more effectively attenuated and eliminated through this sealing action.

In the present invention, in order to obtain the above-mentioned sealing effect, a sealed chamber is hermetically connected to a discharge port of a vacuum pump or the like via a nipple or other connecting means.

This sealed chamber is composed of a sealed chamber forming member and elastic pulp, and when the air pressure inside the sealed chamber exceeds a predetermined value, the air pressure pushes up the pulp and the air is discharged from the gap formed thereby. It has become.

Still another feature of the present invention is that a cover having an expansion chamber is attached to surround the pulp, preferably the volume of the expansion chamber is larger than the volume of the closed chamber, and the pressure inside the closed chamber is relatively high. air is introduced into the expansion chamber to increase the expansion effect, thereby making it possible to reduce noise even more effectively.

An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 2 is a nipple having an air inflow passage 4, one end of which is screwed into a discharge port of a vacuum pump (not shown), and the other end is
It is airtightly connected to the insertion hole of the sealed chamber forming member A by welding, screwing, or other methods.

The sealed chamber forming member A consists of a bowl-shaped portion 6 (see FIG. 2) that has the nipple insertion hole and is open on the other side, and a circular valve plate portion 8 (see FIG. 3) that closes this opening. .

The pulp plate portion 8 is attached to the open end of the bowl-shaped portion by, for example, spot welding, and has an engaging hole 8a in its center for inserting the pulp 10, and a hole around the retaining hole. A plurality of air outlet ports, or small holes 8b, are formed concentrically and spaced apart from each other by a predetermined distance.

An elastic valve 10 (see FIG. 4) is inserted into the pulp plate portion 8 through its engagement hole 8a, and thus,
A sealed chamber 12 is formed by the sealed member A and the elastic pulp.

The elastic pulp 10 is made of rubber or elastic plastic and has a mushroom shape.

This mushroom-shaped valve is composed of an umbrella body portion 10a, a shaft portion 10b extending in one direction from the center of the umbrella body portion, and a locking portion 10c having a larger diameter than the shaft portion formed at the tip of this shaft portion. be.

The canopy body portion 10a having a curved cross section extends in the radial direction from one end of the shaft portion 10b beyond the small hole 8b of the pulp plate portion 8, and its peripheral edge portion is in close contact with the outer surface of the pulp plate portion 8, and the canopy body portion 10a has a curved cross section. A hollow chamber is defined by the inner surface of the body portion and the outer surface of the plate portion.

The shaft portion 10b has a slightly larger diameter than the valve engaging hole 8a,
Further, the shaft portion of the locking portion 10c also has a larger diameter, but it goes without saying that both of these portions must have a compressed diameter that allows them to be inserted into the engagement hole.

In this embodiment, the locking portion 10c has a substantially conical shape, and its bottom surface is in close contact with the inner surface of the pulp plate portion 8, specifically, the inner surface of the plate portion near the pulp engagement hole 8a, thereby preventing the shaft portion from being pulled out. The conical tip faces the air inflow passage 4 at a predetermined distance, and the sound waves that enter from the passage collide with the conical surface and are reflected in various directions. The sound is muffled by the bending effect.

As can be understood from the above, in the silencer of the present invention, the sealed chamber 12 is formed by the sealed chamber forming member A and the pulp 10, and the air accompanied by noise from the air inflow passage 4 is It expands and is attenuated within a closed chamber, and is at least temporarily confined within the chamber, effectively muffling it.

Then, when the pressure inside the sealed chamber reaches a predetermined level or higher, air passes through the small hole 8b and enters the hollow chamber, pushes up the canopy portion 10a, and flows out into the atmosphere.

At this time, the air collides with the inner surface of the umbrella body portion 10a, undergoes a sudden change in direction, and is discharged into the atmosphere while rapidly expanding, thereby further muffling the sound.

Thus, as can be seen, the pulp 10 is forced up by the pressurized air from the closed chamber or its periphery expands away from the outer surface of the plate portion 8, allowing air to escape through the gap. It must have sufficient elasticity.

It is no longer the case that the degree of elasticity is regulated by various conditions such as the material and wall thickness of the pulp itself, the air pressure to be discharged, the volume of the sealed chamber, and the size and number of small holes.

Reference numeral 14 is a cover having an expansion chamber 16, and this cover is open at one end and is fitted onto the periphery of the sealed chamber forming member A through the periphery of this opening.

This cover surrounding the pulp 10 is preferably provided with an expansion chamber 16 having a larger volume than the closed chamber 12, and expands the air that has passed through the pulp to attenuate and muffle the air, and causes it to flow out through an air outlet 18. It looks like this.

Although one embodiment of the present invention has been described above based on the accompanying drawings, the present invention is not limited thereto, and it is of course possible to make various changes within the scope of the innovative technical idea. .

Thus, according to the present invention, the sound waves carried by the air from the discharge port are not cased, but are deflected by colliding with the pulp locking part and the inner surface of the plate part in the closed chamber, and the sound waves are deflected inside the sealed chamber, and the sound waves are deflected inside the sealed chamber, and the sound waves are deflected inside the sealed chamber. The sound is effectively damped by expanding in the plate part, and then it impinges on the inner surface of the canopy part through a small hole in the plate part, and rapidly expands through the gap while changing direction, thereby further damping and muffling the sound.

The pressure in the sealed chamber formed by the casing, the sealed chamber forming member, and the pulp is significantly higher than that in the expansion chamber formed by the cover due to the resistance of the umbrella part of the pulp, so the expansion effect becomes stronger. Provides effective sound deadening.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of a silencer according to the present invention. FIG. 2 is a cross-sectional view of a bowl-shaped portion constituting the sealed chamber forming member. FIG. 3 is a plan view of a pulp plate portion constituting the sealed chamber forming member. FIG. 4 is a cross-sectional view of the pulp. 2... Nipple, 4... Air inflow passage, A... Sealed chamber forming member, 6... Bowl-shaped portion, 8...
・Pulp plate part, 10...Pulp, 10
a...Umbrella body part, 10b...Shaft part, 1
0e...Locking part, 12... Sealed chamber, 1
4... Cover, 16... Expansion chamber, 18
...Air outlet.

Claims (3)

[Scope of utility model registration request] (1) It has a sealed chamber forming member that forms a sealed chamber that communicates with an air inflow passage connected to a discharge port of a vacuum pump or the like;
This sealed chamber forming member includes a pulp plate member, and this plate portion is provided with a valve engagement hole in its center, and a plurality of air outlet ports are provided in the casing b, and the pulp engagement hole is provided in the center of the plate portion. It further includes a pulp that is inserted into and supported by the engagement hole, and this pulp includes a shaft portion that is inserted and locked into the engagement hole, and a pulp that extends from one end of the shaft portion in a radial direction beyond the plurality of air outlet ports. and an umbrella portion extending and having a peripheral edge in close contact with the surface of the valve plate portion, the valve being made of an elastic material and being opened and closed by air pressure passing through the plurality of air outlet ports. A silencer characterized by: (2) The silencer according to claim (1), wherein a cover is attached to the periphery of the sealed chamber forming member to surround the valve. (3) The volume of the expansion chamber formed by the inner periphery of the cover and the pulp plate portion is larger than the volume of the sealed chamber and is provided with an air outlet. A silencer according to scope (2).