JPS6315650Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention significantly improves the airtight performance of the piston ring attached to the piston head, for example, regarding the piston of an electromagnetic reciprocating motor used in compression equipment, pumps, etc. It concerns pistons.

(Prior art and its problems) Piston rings wear out due to repeated reciprocating movements of the piston, and the airtightness deteriorates, resulting in a decrease in compression efficiency and vacuum rate, so they require periodic replacement. As a result, the more frequently used equipment had to replace its piston rings, the more often the piston rings had to be replaced, which tended to place a greater financial burden on the equipment.

The present invention was developed in consideration of the various circumstances mentioned above, and its purpose is to improve the compression efficiency or vacuum rate of compression equipment by further improving the sealing performance between the piston and cylinder. Furthermore, the present invention aims to provide an economical piston that has excellent airtight performance and is capable of reducing the frequency of piston ring replacement due to wear compared to conventional piston rings.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention forms a ring fitting groove deeper than the wall thickness of the piston ring at the piston ring fitting position of the piston body. A hollow ring made of an elastic material such as rubber or soft synthetic resin is fitted to the bottom of the ring fitting groove, and an air reservoir is formed inside the hollow ring. An opening communicating with the air reservoir is formed on one surface thereof, and a sealing member for sealing one inner wall of the fitting groove is provided at one end of the upper portion of the other surface, extending integrally with the hollow ring body, Furthermore, a piston ring having a groove width of the fitting groove is fitted on the outer peripheral surface of the hollow ring body, one side of the piston ring is closely sealed to the sealing member, and the other side of the piston ring is fitted. A configuration was adopted in which a minute gap was provided between the inner wall of the groove and this minute gap communicated with the air reservoir chamber.

(Function) According to the present invention, during the reciprocating movement of the piston body, the air around the piston body has a relative velocity due to the velocity of the piston body, and air flows into the air reservoir chamber of the hollow ring body through a minute gap. As a result, the outer periphery of the hollow ring body is expanded outward, and the piston ring is brought into pressure contact with the inner wall surface of the cylinder. In this state, the amount of air flowing into the air reservoir chamber is the minimum necessary, so the piston body can repeat smooth reciprocating movements and maintain airtightness between the cylinder and the piston.

(Example) The present invention will be described below based on an illustrated example.

FIG. 1 is a partially omitted half-cut sectional view of a piston body according to the present invention, FIG. 2 is an enlarged sectional view of a main part thereof, and FIG. 3 is an overall perspective view of a piston ring to be used in another embodiment. The piston body of this embodiment is, for example, a piston body of an electromagnetic reciprocating motor to be used in a compression device, and the piston body performs reciprocating motion by repeated excitation of an electromagnetic coil.

In the figure, 1 is the piston body, 2 is the piston rod,
3 is a piston head;
A ring fitting groove 4, which is deeper than the wall thickness of the piston ring, is formed on the outer peripheral surface of the piston ring.

Reference numeral 5 denotes a hollow ring body made of an elastic material such as rubber or soft synthetic resin, and inside the hollow ring body 5, an air reservoir chamber 5a is formed with an opening 5c on one side. The hollow ring body 5 is fitted into the bottom of the ring fitting groove 4. Further, in this embodiment, when fitting the hollow ring body 5, the opening 5c side of the air reservoir chamber 5a is directed toward the rear of the ring fitting groove 4, and the hollow ring body 5 is fitted into the ring fitting groove 4. .

5' is a sealing member that seals between one inner wall of the ring fitting groove 4 and the piston ring 6 described later, and in this embodiment, the sealing member 5' is integrally attached to one end of the upper part of the hollow ring body 5 The sealing member 5' is interposed between the inner wall of the ring fitting groove 4 and a piston ring 6, which will be described later, to maintain the sealing properties of the joint surfaces thereof.

6 is a piston ring to be fitted into the ring fitting groove 4, and the piston ring 6 is, for example, a third piston ring.
As shown in the figure, a cut 6a such as a step cut is provided so that the piston ring 6 can be expanded freely.
It is fitted on top of b.

In addition, in the above-mentioned fitted state, the ring fitting groove 4
A minute gap 7 as shown in FIG. 2 is provided between the rear inner wall of the piston ring 6 and the piston ring 6, and the gap 7 forms an air flow path that communicates the outside of the piston body with the air reservoir chamber 5a.

Incidentally, if a cutout groove 7' is provided on one outer side surface 6b of the piston ring 6 as in the other embodiment shown in FIG.
Even if the piston ring 6 is tightly fitted into the ring fitting groove 4, it is possible to form the air passage 7 as shown in FIG. Since the outer circumferential surface 6b is in close contact with the inner wall of the ring fitting groove 4, rattling of the piston ring 6 can be reliably prevented.

In addition to providing the air passage 7 at the above-mentioned position, the air passage 7 may be formed by boring a through passage at an appropriate position in the piston body 1. Further, in this embodiment, the air passage 7 is provided at the rear of the ring fitting groove 4, but the air passage 7 is provided at the front of the ring fitting groove 4, and the air passage 7 is provided at the front of the ring fitting groove 4. Opening 5c of reservoir chamber 5a
Similarly, by directing the ring fitting groove 4 toward the front, the two may be communicated with each other.

Next, the operation of the above embodiment will be explained based on FIG. 2.

During reciprocating motion of the piston body 1, when the piston body 1 retreats in the direction of arrow A, the air around the piston body 1 has a relative velocity in the direction of arrow B due to the speed of the piston body 1, and as a result, the air flow Air flows into the air reservoir chamber 5a through the passage 7. Therefore, air pressure is generated in the air reservoir chamber 5a, and due to this pressure, the piston ring 6 fitted on the outer periphery of the hollow ring body 5 is expanded outward and pressed against the inner wall surface of the cylinder (not shown). In this state, the reciprocation of the piston body is repeated, and while the piston body performs smooth reciprocation, the airtightness between the cylinder and the piston body is further improved.

(Effects of the invention) As described above, the present invention has the following useful effects.

That is, it is possible to reliably press the piston ring against the inner wall of the cylinder by air pressure and repeat the reciprocating movement of the piston body, which is excellent in maintaining airtightness between the cylinder and the piston body. In particular, the piston ring is almost as wide as the fitting groove, so the piston ring is stably fitted into the fitting groove, and the amount of air entering the air reservoir is regulated, so the piston ring This prevents the ring from unnecessarily expanding in the centrifugal direction, and enables smooth reciprocating movement of the piston body.

In addition, even if the piston ring is slightly worn, the air pressure in the air reservoir chamber can sufficiently push the piston ring outward and bring it into pressure contact with the cylinder inner wall, resulting in sufficient airtightness. Since the piston rings can be held, it is possible to reduce the frequency of piston ring replacement, which is extremely economical.

[Brief explanation of drawings]

The drawings show one embodiment of the piston body according to the present invention, FIG. 1 is a partially omitted half-sectional view thereof, FIG. 2 is an enlarged sectional view thereof, and FIG. 3 is another embodiment of the present invention. 1 is an overall perspective view of a piston ring to be used for. 1... Piston body, 4... Ring fitting groove, 5
...Hollow ring body, 5'...Sealing member, 5a...Air reservoir, 5c...Opening, 6...Piston ring, 7...Minute gap (air flow path).

Claims (1)

[Scope of utility model registration request] A ring fitting groove deeper than the wall thickness of the piston ring is formed at the piston ring fitting position of the piston body, and a hollow ring body made of an elastic material such as rubber or soft synthetic resin at the bottom of the ring fitting groove. an air reservoir is formed inside the hollow annular body, and an opening communicating with the air reservoir is formed on one of both sides of the hollow annular body, and an upper end of the other surface is formed. A sealing member for sealing one inner wall of the fitting groove is provided integrally with the hollow ring body, and a piston ring having a groove width of the fitting groove is fitted on the outer peripheral surface of the hollow ring body. Then, one side of the piston ring is closely sealed to the sealing member, a minute gap is provided between the other side of the piston ring and the inner wall of the fitting groove, and this minute gap is communicated with the air reservoir chamber. A piston of an electromagnetic reciprocating motor characterized by: