JPS6332937Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vacuum pump muffler that can be mounted compactly and in a well-balanced manner on the exhaust port of a vacuum pump and has a good sound-dampening effect.

[Prior art]

2. Description of the Related Art Conventionally, there are various mufflers for muffling the sound of air being exhausted from an exhaust port, which is generated by the pumping action of a vacuum pump. However, in the conventional muffler, in order to increase the muffling effect, the muffler as a whole is large and takes up space when attached to a vacuum pump, and the balance is poor. In addition, there are silencers that have a complicated internal structure to increase the noise reduction effect and are smaller, but this kind of complicated internal structure has a large exhaust resistance and has the disadvantage of reducing the pump efficiency of the vacuum pump. . On the other hand, since the displacement of a vacuum pump significantly changes depending on the vacuum pressure to be reached, it has been difficult to maintain a sound-dampening effect over a wide range from low vacuum pressure to high vacuum pressure.

[Problem that the invention attempts to solve]

The present invention was developed in view of the above points, and its purpose is to be able to be installed compactly and in a well-balanced manner at the exhaust port of a vacuum pump, and to be able to operate from low vacuum pressure to high vacuum without reducing pump efficiency due to small noise-damping resistance. An object of the present invention is to provide a silencing device for a vacuum pump that has a high silencing effect over a wide range of pressures.

[Means for solving problems]

The gist of the present invention is to include a silencing chamber having an exhaust inlet that can be fitted into the exhaust port of a vacuum pump, an exhaust outlet through which the exhaust gas from the vacuum pump that enters from the exhaust inlet flows out, and a supporting arm that is erected on the silencing chamber. and a lid body which is supported by a rod to which the exhaust outlet is attached, and which presses against the peripheral edge of the exhaust outlet by the elastic force of a coil spring or the like to close the exhaust outlet. The piston is slidably fitted into the lid body, and its outer peripheral surface slides on the lid inner peripheral surface.The piston is elastically supported and faces the exhaust outlet, and the lid The structure is such that the volume of the silencing chamber and the opening amount of the exhaust outlet can be automatically adjusted by displacing the body and the piston. Hereinafter, embodiments will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, which includes an exhaust inlet 1a that can be screwed into an exhaust port (not shown) of a vacuum pump, and an outlet through which exhaust gas entering from the exhaust inlet 1a flows out. It has a muffling chamber 1 having an exhaust outlet 1b which is an opening, and a cap-shaped lid body 6 having a cylindrical inner circumferential surface that can be closed by covering the exhaust outlet 1b of the muffling chamber 1. Central outer surface 3 of chamber 1
For example, the cross section is formed in a hexagonal shape so that the exhaust inlet 1a can be screwed onto the exhaust port of the vacuum pump with a tool etc., and the peripheral edge 9 of the exhaust outlet 1b is a ring-shaped flat surface. . A support arm 4 is provided integrally with the inner wall surface 2 of the silencing chamber 1, and one end 5a of a rod 5 passing through the center of the outlet 1b is fixed to an end 4a of the support arm 4. ing. The lid body 6
A cylindrical guide 6a, which is provided so as to pass through the center thereof, is slidably fitted onto the rod 5, and a compression spring fixing nut 8 fixed to the other end 5b of the rod 5 and the lid body. 6, the end edge 10 of the lid, which has a ring-shaped flat surface similar to the peripheral edge 9 of the exhaust outlet, is biased by the elastic force of the compression spring 7 provided between the It comes into pressure contact with the peripheral edge 9 and closes the opening surface of the exhaust outlet. A piston 12 is provided inside the lid 6, and is slidably fitted onto the rod 5, and whose outer peripheral surface 12a slides on the cylindrical inner peripheral surface of the lid 6.
The piston is elastically supported by a compression spring 11 interposed between the piston and the inner surface of the lid while being fitted onto the outside of the piston.
By pressing the end portion 4a of the supporting arm and facing the exhaust outlet 1b, a silencing chamber space is defined. In the above configuration, when the silencer of the present invention is screwed onto the exhaust port of the vacuum pump and the vacuum pump is driven to discharge air from the exhaust port, the air discharged from the exhaust port will flow into the silencing chamber 1 from the exhaust port 1a. The exhaust pressure causes the piston 12 to spring 11
The lid body 6 is pushed up against the elastic force of the lid body 6.
By pushing up against the elastic force of the compression spring 7, a minute gap A is created between the peripheral edge 9 of the exhaust outlet and the end edge 10 of the lid body, which had hitherto been in contact and blocked the exhaust outlet 1b. occurs, and air is released from this gap A into the outside air. In this way, the exhaust sound of air from the exhaust port generated by the pumping action of the vacuum pump is suppressed because the flow of the exhausted air is restricted by the peripheral edge 9 of the exhaust outlet and the edge 10 of the lid 6. It is reduced by being released into the outside air in the form of a sheet-like high-speed air flow. Note that the lid body 6 is
Since it is pressed against the silencing chamber by the spring 7, the gap A changes automatically according to the displacement of the pump.
Stable and high silencing effect can be obtained over a wide range of pressures, from low vacuum pressure to high vacuum pressure. Further, since the piston 12 inside the lid body 6 is also held in pressure contact with the support arm end 4a by the spring 11, sudden changes in displacement and pulsations are absorbed by the displacement of the piston 12, and the displacement of the lid body 6 is absorbed. Because of this, a more stable sound deadening effect can be obtained. In the embodiment described above, the end edge 10 of the lid body
and the circumferential edge 9 of the exhaust outlet are ring-shaped with the same diameter, but as shown in Fig. 3, by forming the outer diameter of one of them larger than the other, the air flows out from the gap A between the two. The high velocity airflow bends in the direction of the arrow, ie the side having the larger outer diameter. Therefore, this air flow can also be used to cool the vacuum pump, which is a heating element. FIG. 4 shows another embodiment of the present invention, in which the outer wall 42 of the silencing chamber 41 has approximately U
A rod 45 is provided with a protruding support arm 44, one end of which is fixed 43, and the other end of the rod 45 faces near the center of the opening that forms the exhaust outlet of the silencing chamber 41, and a lid is attached to the rod. 46 and the piston 47 slidingly in contact with the circumferential surface of the lid body are urged by the return force of the spring to close the silencing chamber and the protrusion 4 at the other end of the rod 45, respectively.
6 to form a silencing space.

[Effect of idea]

As described above, the muffler of the present invention includes a muffling chamber, a lid body that automatically adjusts the opening amount of the exhaust outlet of the muffling chamber according to the displacement amount of the vacuum pump, and a lid body that is provided inside the lid body and which is arranged to open the exhaust outlet of the muffling chamber. A silencing space is formed by a piston that automatically adjusts the capacity of the silencing space in response to sudden changes in exhaust volume, and a gap formed by the contact surface between the silencing chamber and the lid body forms a silencing section. Therefore, a high silencing effect can be obtained over a wide range from low vacuum pressure to high vacuum pressure, and since the structure is compact, it has the effect of being able to be installed in a well-balanced manner on the vacuum pump.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing one embodiment of the present invention, Fig. 2 is a cross-sectional view showing the operating state of the embodiment of Fig. 1, and Fig. 3 is a main part of another embodiment of the present invention. FIG. 4 is a sectional view showing still another embodiment of the present invention.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A silencing chamber having an exhaust inlet that can be fitted into the exhaust port of a vacuum pump and an exhaust outlet through which the exhaust gas entering from the exhaust inlet flows out, and a supporting arm that stands on the silencing chamber. supported by a rod attached at one end to the
and a lid that presses against the circumferential edge of the exhaust outlet by elastic force to close the exhaust outlet, the rod is slidably fitted into the lid, and the outer circumferential surface is inside the lid. The capacity of the silencing chamber and the opening of the exhaust outlet are formed by resiliently supporting a piston that slides on the circumferential surface and facing the exhaust outlet, and in which the lid body and the piston are displaced in accordance with fluctuations in the displacement of the vacuum pump. A vacuum pump silencer that automatically adjusts the volume. (2) The lid is slidably fitted into a rod that passes through the center of the exhaust outlet and has one end fixed to a supporting arm that projects from the wall of the sound-deadening chamber, and is elastically supported by a coil spring. 2. The muffler according to claim 1, wherein the muffler is pressed against the exhaust outlet. (3) The device according to claim 1, wherein the support arm is fixed to the outer wall of the sound deadening chamber. (4) The peripheral edge of the exhaust outlet and the end edge of the lid that abuts the exhaust outlet both form a ring-shaped flat surface, and the flat surfaces abut against each other to close the exhaust outlet. A silencer as described in any of the above. (5) The muffler according to claim 4, wherein the outer diameter of the ring-shaped plane is larger than the outer diameter of the other ring-shaped plane that abuts each other.