JP2816988B2 - Automatic discharge structure of oil-cooled compressor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an automatic discharge structure of compressed gas in a compressor, particularly an oil-cooled compressor having an automatic start / stop mechanism.

[Prior Art] FIG. 2 shows a general configuration of a conventional compressor. Compressor 12
The compressed air is introduced into the receiver tank 15 by the discharge pipe 13 and the check valve 14, separated by the oil separator 16 into oil and gas, and sent to the place of use by the delivery pipe 17. The oil 18 separated in the receiver tank 15 is returned to the compressor 12 via the return pipe 19 and the aftercooler 35. An oil cooler 35 and a solenoid valve 20 are provided in the return pipe 19. An automatic discharge valve 4 is provided above the receiver tank. Automatic release valve 4
The operation pressure introduction port 9 is connected to a discharge pipe 13 and a pipe 22, and the compressed air introduction port 19 communicates with the oil separator 16 in the receiver tank 15 by a pipe 23. Reference numeral 11 denotes a silencer. A pressure detecting means 24 is provided in the delivery pipe 17, and a signal from the pressure detecting means 24 is input to the compressor 12 and the solenoid valve 20 by the relays 36 and 37 in the passage 25 and the passage 26. It is configured to perform an opening and closing operation.

FIG. 3 shows an example of the detailed structure of the automatic discharge valve 4.

A passage communicating with the inlet 9 and the compressed air inlet 10 is formed in the main body 27, and the inlet 9 communicates with the diaphragm chamber 28. A small passage 30 communicating with the compressed air inlet 10 is opened on the seating surface of the main body 27 with which the diaphragm 29 contacts. Also the body
A small passage 31 is provided in 27, and communicates with the silencer 11 screwed to the plug 32. The plug 32 is provided with a throttle passage 33 having a diameter d communicating with the small passage 31 and the silencer 11.

[Problems to be Solved by the Invention] In the conventional compressor described above, when the use of compressed air at the place of use decreases or stops, the pressure in the delivery pipe 17 increases and a detection signal is generated from the pressure detecting means 24. Can be done. As a result, the compressor stops, and the solenoid valve 20 is closed. Third
In the figure, during operation, the pressure on the inlet 9 side and the compressed air inlet
Since the pressure on the side 10 is substantially the same and the diaphragm chamber 28 has a larger area than the small passage 30, the diaphragm 29 is pressed against the seating surface side of the main body 27 and the small passage 30 is closed. However compressor
When 12 stops, the pressure on the inlet 9 side decreases, and the pressure of the oil separator 16 in the receiver tank 15 acts on the compressed air inlet 10. Therefore, the diaphragm 29 is opened and the small passage 30 is opened.
Communicates with the small passage 31, passes through the throttle passage 33, and
, And the pressure in the receiver tank 15 gradually decreases. When the pressure in the receiver tank 15 decreases, the pressure applied to the oil 18 accumulated in the receiver tank 15 decreases. As shown in FIG. Occur. The bubbles 34 come into contact with the oil separator 16 to reduce its function, and the oil 18 in the bubbles 34 entering the oil separator 16
Side, and there is a problem that oil flows into the place of use.
For this reason, in the prior art, as shown in FIG. 3, a throttle passage 33 having a diameter d is provided in the automatic discharge valve 21 to gradually discharge compressed air to prevent a sudden decrease in the pressure in the receiver tank 15 and to reduce the degree of foaming. Is to be reduced. However,
Even if foaming is prevented, it takes a considerable time for the compressed air in the receiver tank 15 to be released and the internal pressure to drop. Receiver tank 15 for automatic start-stop compressor
When the internal pressure is reduced to a certain pressure, the restart is started. Therefore, if the release from the automatic release valve 11 takes a long time, the restart takes a long time. Further, it takes time to restart and increase the pressure in the receiver tank 15, and there is a problem in terms of energy saving. Further, the oil 18 remaining in the receiver tank 15 is pressure-fed to the compressor 12 by the pressure in the receiver tank 15, so that
If the engine is started with the pressure of zero at zero, poor lubrication due to oil injection and sending and abnormally high temperature due to insufficient cooling will occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems and solving the problems. Even when the compressor is stopped, the pressure in the receiver tank does not decrease, the automatic start / stop time is short, and unnecessary compressed air is smoothly and automatically. An object of the present invention is to provide an automatic discharge structure of a discharged oil-cooled compressor.

Means for Solving the Problems In order to achieve the above object, the present invention provides an oil-cooled compressor that discharges compressed air discharged from a compressor through a check valve into a receiver tank. A small-volume chamber is interposed between the check valve and the receiver tank, and a check valve is interposed between the small-capacity chamber and the receiver tank to prevent backflow from the receiver tank side to the small-volume chamber side. An automatic discharge structure of the compressor is provided in which an automatic discharge valve is interposed between the small volume chamber and the discharge side of the compressor.

[Operation] When the compressor is stopped, only the compressed air in the small volume chamber is discharged from the automatic discharge valve attached to the small volume chamber. Since the receiver tank does not communicate with the automatic release valve, the pressure does not decrease below.
Since the small volume chamber has a smaller volume than the receiver tank, the discharge time is short, and the compressed air of the predetermined pressure can be discharged to the place of use in a short time even at the time of restart.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIG. 1, the same reference numerals as those in FIGS. 2 and 3 denote the same components or components having the same functions, and a description thereof will be omitted.

A small volume chamber 1 is interposed between the compressor 12 and the check valve 14 in the discharge pipe 13 connecting the compressor 12 and the receiver tank 15 via a check valve 14, and the small volume chamber 1 and the compressor 12 A check valve 3 for preventing a backflow to the compressor 12 is provided between them. The small volume chamber 1 is connected to an automatic discharge valve 4 by a pipe 8 via an oil separator 2.
Are linked. The oil separator 2 is connected to the discharge pipe 13 by a pipe 5. The branch pipe 6 from the discharge pipe 13 is connected to the inlet 9 of the automatic discharge valve 4.

When the compressor 12 is operated, the compressed air passes through the discharge pipe 13, opens the check valve 3, fills the small volume chamber 1 with compressed air, opens the check valve 14, and compresses the compressed air into the receiver tank 15. Send air. As described above, the automatic discharge valve 4 does not discharge the compressed air because the pressure of the compressed air in the pipes 6 and 8 is the same.

When the compressor 12 stops, the pressure in the discharge pipe 13 decreases, but the check valve 3 prevents the compressed air in the small volume chamber 1 from flowing back to the compressor 12 side. However, the automatic discharge valve 4 is opened by the pressure difference between the pipe 8 and the pipe 6, and the compressed air in the small volume chamber 1 is discharged from the automatic discharge valve 4 while being separated into oil and gas by the oil separator 2.

Since the check valve 14 is interposed between the receiver tank 15 and the small volume chamber 1, there is no backflow from the receiver tank 15 and no pressure drop in the receiver tank 15 occurs. Therefore, foaming is prevented. On the other hand, the amount of air released from the small-volume chamber 1 is small, and the oil in the small-volume chamber 1 at the time of stoppage is only the oil that passes through the small-volume chamber 1 and is in the small-volume chamber 1. It can be released in a very short time with little fear of foaming. Further, since the oil and gas are separated by the oil separator 2, the oil is hardly released from the automatic discharge valve 4.

In the case of automatic start and stop, the discharge from the small volume chamber 1 is performed in a short time, and the compressed air in the receiver tank 15 is kept as it is. Start and stop will be performed.

In the present embodiment, the capacity value of the small volume chamber 1 is not shown, but is set as appropriate according to the capacity of the compressed air 12 and the receiver tank 15, and is not particularly limited. Further, there is no oil reservoir in the small volume chamber 1, and the amount of oil released to the outside is small.

[Effects of the Invention] As is apparent from the above description, according to the present invention, the pressure in the receiver tank does not decrease, and unnecessary automatic discharge of compressed air when the compressor is stopped is performed smoothly in a short time. In addition, the automatic start / stop time is short, and the effect that the operation can be performed relatively easily and simply is obtained.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention, FIG. 2 is an overall configuration diagram of a compressor having a conventional automatic discharge structure, and FIG. 3 is a sectional view of an automatic discharge valve. 1… Small volume chamber, 2,16 …… Oil separator, 3,14 ……
Check valve, 4 ... Automatic release valve, 5, 6, 7, 8 ... Piping, 9 ...
Compressed air inlet, 10 ... Inlet, 11 ... Silencer, 12
…… Compressor, 13 …… Discharge pipe, 15 …… Receiver tank,
17 ... delivery pipe, 18 ... oil, 19 ... return pipe, 20 ... solenoid valve, 24 ... pressure detection means, 27 ... body, 29 ... diaphragm, 30, 31 ... small passage, 33 ... … Throttle passage, 34 …… bubble, 3
5 ... Aftercooler.

Claims (1)

(57) [Claims] 1. An oil-cooled compressor for discharging compressed air discharged from a compressor into a receiver tank through a check valve, wherein a small volume chamber is interposed between the check valve and the receiver tank. A check valve is provided between the small-capacity chamber and the receiver tank to prevent backflow from the receiver tank side to the small-volume chamber side, and a check valve is provided between the small-capacity chamber and the discharge side of the compressor. The automatic release structure of the oil-cooled compressor, characterized in that an automatic release valve is interposed in the compressor.