JPS6320871Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a check valve for a compressor, specifically a compressor equipped with a plurality of cylinders and an unload valve for unloading at least one of these cylinders. The present invention relates to a check valve interposed between the discharge chamber having the unload valve and the discharge side of another cylinder to prevent backflow of compressed gas.

This type of check valve is disclosed in Japanese Utility Model Application Publication No. 57-142183, and the one shown in FIG. 4 has already been proposed.

In FIG. 4, 50 is a discharge chamber communicating with a cylinder (not shown) that enables unloading;
51 is an unload valve provided in the chamber 50;
Further, 52 indicates the discharge chamber 50 and the other cylinder 5.
This is a collecting ring that communicates with the discharge side of No. 3.

Reference numeral 54 denotes a check valve that is slidably installed inside the valve hole 55 and opens and closes a passage 56 that communicates the collecting ring 52 and the discharge chamber 50.

The check valve 54 is connected to the unloading valve 5
During the closing operation of the unloading valve 51, i.e., during load operation, the discharge pressure of the one cylinder keeps the open position as shown by the solid line in FIG. 4. During the opening operation of the unloading valve 51,
That is, during unloaded operation, the check valve 54 is maintained in a closed position as shown by the dotted line in FIG. 4 by the discharge pressure of the other cylinders 53 acting on the back surface 54a side of the check valve 54.

However, the check valve 54 configured in this manner has the problem of chattering and noise during road operation.

As a result of research, the cause of this problem is that there is a phase in the compression cycle of each cylinder, and during load operation, a process in which one cylinder is in the intake stroke and the other cylinder 53 is in the discharge stroke occurs periodically. Each time, the back face 54a side of the check valve 54, that is, the collecting ring 52
The pressure on the front side, that is, the discharge chamber 5
Creates a reverse differential pressure that is slightly higher than the pressure on the 0 side,
It has been found that the check valve 54 is at the point where it is pushed to the closed position by this reverse differential pressure.

Therefore, the purpose of the present invention is to provide a sliding resistance to the check valve between the check valve and the valve hole in order to absorb the pushing force due to the reverse differential pressure that acts on the check valve during load operation. A resistance ring is provided to prevent the check valve from chattering during load operation.

For this purpose, the structure of the present invention is installed inside the valve hole,
The valve body is held in an open position during load operation of the compressor between the sliding surface of a valve body having a sliding surface that comes into sliding contact with the inner surface of the valve hole and the inner surface of the valve hole; During unloading operation, a resistance ring is provided to provide a sliding resistance that allows the valve body to slide to the closed position.

Hereinafter, embodiments of the present invention will be described based on the drawings.

The compressor shown in FIG. 1 is a two-cylinder hermetic compressor using the check valve of the present invention, and capacity control can be performed by operating with one cylinder unloaded.

Briefly explaining the compressor shown in FIG. 1, 1 is a closed casing, and a compression element 3 having two cylinders 2 (only one shown) and a motor M are housed inside the casing 1. and one of the cylinders 2
and a cylinder top cover 6 forming a discharge chamber 5 having an unload valve 4 to enable unload operation.
We will set up the following.

In FIG. 1, reference numeral 7 denotes a collection ring that once collects the discharged gas discharged from each cylinder 2, and the discharged gas is discharged to the outside of the machine through the collection ring 7. Further, 8 is an operation tube for operating the unload valve 4.

Furthermore, 9 is a piston, and 10 is a drive shaft. Furthermore, a check valve 12 for opening and closing a passage 11 consisting of an internal passage 11a and a discharge pipe 11b communicating between the discharge chamber 5 and the collecting ring 7 is provided as described below.

That is, as shown in FIGS. 2 and 3, the check valve 12
The valve body has a valve hole 13 formed in a part of the internal passage 11a, and is installed inside the valve hole 13 so that the valve hole 13 can slide freely, and has a sliding surface 14 that comes into sliding contact with the inner surface of the valve hole 13. 15 and a valve seat 17 that opens and closes a seat surface 16 provided on the front surface of the valve hole 13, that is, on the side of the discharge chamber 5.

Specifically, the valve body 15 is connected to the check valve 12.
On the rear side in the sliding direction (the collecting ring 7 side), there is a circular portion 15a having the annular sliding surface 14, and a circular portion 15a having a substantially square cross section and continuous with the sliding surface 14 at each corner thereof. It consists of a square portion 15b on which a sliding surface 18 is formed. Further, this valve body 15 has the circular portion 15
a and the square part 15b, and forms a lumen part 15c which is open to the back side, and which penetrates the side wall of the prismatic part 15b.
Four passages 15d are formed to communicate between the valve hole 13c and the seat surface 16 side of the valve hole 13.

In addition, 19 is a valve seat holder. Further, 20 is a lid body that closes the valve hole 13.

In the check valve 12 configured as described above, an annular groove 21 is provided on the sliding surface 14 of the circular portion 15a,
A resistance ring 22 made of a piston ring is attached to the groove 21 in sliding contact with the inner surface of the valve hole 13. Moreover, the magnitude of the sliding resistance of this resistance ring is determined as follows.

That is, during load operation of the compressor with the unload valve 4 in the closed position, the discharge chamber 5
Due to the reverse pressure difference generated between the side and the collecting ring 7 side, the pushing force acting on the back surface of the valve body 15 can be absorbed, and the valve body 15 can be held in the open position.
The size is such that the valve body 15 is allowed to slide during unloading operation when the unload valve 4 is in the open position and can be slid to the closed position.

With this configuration, during road operation, the discharge pressure of the cylinder 2 acts on the front side of the check valve 12, pushes up the check valve 12, holds it in the open position, and prevents discharge from the cylinder 2. The discharged gas is led from the discharge chamber 5 to the collecting ring 7 via the internal passage 11a, the passage 15d of the check valve 12, the inner cavity 15c, and the discharge pipe 11b.

During this load operation, since there is a phase in the compression cycle of the cylinder 2, even if the reverse differential pressure acts on the check valve 12, the pushing force due to the reverse differential pressure is absorbed by the resistance ring 22. Since it can be absorbed by frictional force (sliding resistance), the check valve 12 does not slide, and as a result, no chattering occurs.

Furthermore, by preventing chattering in this manner, the durability of the valve seat 17 of the check valve 12 can also be improved.

Note that during unloading operation, the differential pressure between the discharge gas pressure of other cylinders acting on the back surface of the check valve 12 and the low pressure acting on the front surface (valve seat 17 side) is very large, so the non-return valve 12 The valve 12 easily slides into the closed position despite the sliding resistance of the resistance ring 22.

As described above, according to the present invention, between the sliding surface 14 of the valve body 15 of the check valve 12 and the inner surface of the valve hole 13, the valve body 1
5 in the open position and allows the valve body 15 to slide during unloading operation, and is provided with a resistance ring 22 that provides sliding resistance to allow the valve body 15 to slide to the closed position.
Chattering of the check valve 12 during load operation of the compressor can be reliably prevented.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of a compressor using a check valve according to the present invention, FIG. 2 is an enlarged vertical sectional view of the check valve,
FIG. 3 is an enlarged cross-sectional view taken along line XX in FIG. 2, and FIG. 4 is an explanatory diagram showing a conventional example. 2...Cylinder, 4...Unload valve, 5...Discharge chamber, 13...Valve hole, 14...Sliding surface, 1
5... Valve body, 22... Resistance ring.

Claims (1)

[Scope of utility model registration request] A check valve for a compressor that is provided with a plurality of cylinders, communicates with at least one cylinder 2, and is interposed between a discharge chamber 5 having an unload valve 4 and the discharge side of another cylinder. The sliding surface 14 of a valve body 15 having a sliding surface 14 that is installed inside the valve hole 13 and comes into sliding contact with the inner surface of the valve hole 13 and the valve hole 13
A sliding member is provided between the inner surface of the compressor and the valve body 15 to hold the valve body 15 in the open position during loading operation of the compressor, and to allow the valve body 15 to slide to the closed position during unloading operation of the compressor. A check valve for a compressor, characterized in that it is provided with a resistance ring 22 that provides resistance.