JPS6112401Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a compressed air decompression device that improves the safety of a compressed air system and makes effective use of compressed air.

[Prior art]

A conventional example of a compressed air system having a pressure reducing device will be described with reference to FIG.

In FIG. 1, high pressure air from a high pressure air source (not shown) is introduced from a shutoff valve 1 through a line 2 to a pressure reducing valve 3, and the compressed air whose pressure is reduced by the pressure reducing valve 3 is passed through a line 4. The air is then stored in the air tank 5. The compressed air in the air tank 5 is supplied via a pipe line 6 and a shutoff valve 7 to equipment (not shown) that is controlled by low-pressure compressed air. In addition, the air tank 5 has a drain valve 8 that removes the drain, and high-pressure air that is not reduced in pressure due to a failure in the pressure reducing valve 3 flows into the air tank 5, and when the pressure in the air tank 5 rises above a specified pressure, high-pressure air is released. A safety valve 9 is provided.

Here, the safety valve 9 is designed so that the blowing pressure and the shutoff pressure can be set arbitrarily, which are larger than the ventilation capacity of the pressure reducing valve 3. Therefore, when the pressure in the air tank 5 reaches or exceeds a specified pressure, the safety valve 9 blows, and when the high-pressure air is released and the pressure falls to a safe level below the specified pressure, the blowing stops.

[Problem that the invention attempts to solve]

However, in a compressed air system having a pressure reducing device as described above, there are the following problems.

(1) Malfunction of the safety valve If the pressure reducing valve 3 does not operate due to a malfunction and the pressure in the air tank 5 exceeds the specified pressure without reducing the pressure as expected, the safety valve 9 should operate, but the air tank If the safety valve 9 fails and does not operate even if the pressure in 5 exceeds the specified pressure,
There is a risk of high pressure air flowing into the equipment on the low pressure side and damaging the equipment.

(2) Waste of compressed air If the capacity of the high pressure air source is large, use the pressure reducing valve 3.
If the air tank 5 malfunctions, the pressure in the air tank 5 will exceed the specified pressure and the safety valve 9 will blow out, and when the pressure reaches a safe level, it will blow up, so it is safe, but high pressure air is continuously supplied to the air tank 5 from the high pressure air source. Therefore, in a short period of time, the air tank 5 becomes over the specified force again and the safety valve 9 blows out. Safety valve like 9
As the compressor operates repeatedly, the compressed air is emitted into the air without doing any work, which wastes the compressed air and is uneconomical. Furthermore, the repeated operation of the safety valve 9 described above may lead to a secondary failure in which the safety valve 9 freezes, resulting in the problem described in item (1).

On the other hand, if the capacity of the high-pressure air source is small, if the safety valve 9 operates repeatedly, the pressure of the high-pressure air source will decrease, which will affect other air systems. Furthermore, if the safety valve 9 operates repeatedly regardless of the capacity of the high-pressure air source, the compressed air generator will operate continuously, which will shorten its life.

This invention was developed to solve the above problems.The purpose is to eliminate the wastage of compressed air due to the repeated operation of the safety valve, and to ensure that even if the safety valve fails, the pressure in the air tank does not exceed the specified pressure. It is an object of the present invention to provide an economical and reliable compressed air decompression device that can prevent air from rising and improve safety.

[Means for solving problems]

In order to achieve the above object, the compressed air pressure reducing device according to the present invention includes a pressure reducing valve that reduces the pressure of high pressure air from a high pressure air source, and is connected downstream of the pressure reducing valve,
It has an air tank that stores low-pressure air to be supplied to equipment controlled by air, and a lock valve that is connected upstream of the pressure reducing valve. A detection side piston is provided, and a seat attached to the lower surface of the high pressure side piston is attached to a valve seat provided intermediate between a first opening communicating with the high pressure air source and a second opening communicating with the pressure reducing valve. The air tank is characterized in that a third opening communicating with the air tank is provided on the upper surface side of the detection side piston and facing each other.

[Effect]

In the compressed air pressure reducing device configured as described above, when the pressure reducing valve is operating normally and pressure is being reduced, the seat is separated from the valve seat by high pressure air from the first opening of the lock. High-pressure air is sent to the pressure reducing valve, but when the pressure reducing valve fails and the original pressure is not reduced, the pressure on the upper surface of the detection piston increases due to the increase in the internal pressure of the air tank, causing the locking valve to close. The flow to the pressure valve will be cut off.

〔Example〕

Hereinafter, details of the present invention will be explained with reference to FIGS. 2 and 3, which are one embodiment. In FIG. 2, the same parts as those in FIG. 1, which is a conventional example, are given the same reference numerals and detailed explanations are omitted, and only the different parts will be described here.

In other words, in FIG. 2, a lock valve 12 is provided between the high pressure side pipe line 2 and the pipe line 11 on the upstream side of the pressure reducing valve 3 in FIG. Pilot pressure is fed through channels 13, 14 and check valve 15.

FIG. 3 shows a detailed configuration example of the locking valve 12 in a sectional view. In FIG. 3, a high pressure side piston 17 and a detection side piston 18 having a larger diameter are slidably inserted into the inside of the valve body 16, which are integrated by an appropriate method. An exhaust valve 19 is provided on the operating side of the detection side piston 18, and the third opening 20 is connected to the pipe line 1.
4 so that pilot pressure can flow in. Further, the second mouth portion 21 on the lower left side of the valve body 16 is connected to the high pressure side pipe line 2, and the first mouth part 22 on the lower right side is connected to the pipe line 11,
The seat 23 provided on the lower surface of the high-pressure side piston 17 comes into close contact with the valve seat 24 when the high-pressure side piston 17 descends, so that the second opening 21 and the first
It is designed to cut off communication between the mouth part 22 of the

Next, the operation of this configuration will be explained.

First, compressed air flows into the lock valve 12 through the shut-off valve 1 and the high-pressure side pipe line 2. At this time, high pressure air acts on the lower surface of the high pressure side piston 17 of the locking valve 12, and low pressure air from the air tank 5 acts on the upper surface of the detection side piston 18, but since the pressure is low,
As shown in FIG.
) The mouth portion 22 is in communication. Therefore, the compressed air passes through the lock valve 12, is reduced in pressure by the pressure reducing valve 3, is stored in the air tank 5, and is supplied to each air device.

Here, in the event that the pressure reducing valve 3 fails and the original pressure reduction is no longer performed, the pressure in the air tank 5 rises to near the specified pressure, and the pressure in the air tank 5 is lowered to the line 13. , 14 and check valve 1
5 acts on the upper surface of the detection side piston 18 from the (third) mouth 20 of the locking valve 12. At this time, the diameter of the detection side piston 18 is larger than the diameter of the high pressure side piston 17, and the working pressures are approximately equal, so each piston 17 and 18 descends to the seat 2.
3 comes into close contact with the valve seat 24 to close it.

As a result, the (second) mouth part 21 and the (first)
Communication between the mouth part 22 is cut off, air no longer flows into the pressure reducing valve 3 and the air tank 5, and the air tank 5
does not rise above the specified pressure, so the air equipment on the low pressure side is protected from high pressure air. Furthermore, even if the air equipment consumes air and the pressure in the air tank 5 decreases, the high pressure air on the upper surface of the detection side piston 18 of the locking valve 12 cannot return to the air tank 5 due to the check valve 15. The (second) mouth 21 and the (first) mouth 22 remain closed, and high pressure air does not flow into the air tank 5, so the locked state continues. Furthermore, when the pressure reducing valve 3 is repaired and the compressed air system returns to normal, the exhaust valve 19 of the locking valve 12 may be opened to reduce the pressure on the operating surface of the detection side piston 18.

As described above, in the compressed air pressure reducing device of this embodiment, when the pressure in the air tank 5 reaches near the specified pressure, the lock valve 12 closes due to the pressure in the air tank 5, and the high pressure air flows into the air tank 5. Since the structure is configured so that no inflow occurs, there is no need to rely on the safety valve 9 even if the pressure reducing valve 3 fails and the original pressure is not reduced, so safety can be extremely improved compared to the conventional structure. In this case, the pressure rise in the air tank 5 is directly detected by the lock valve 12 and the air inflow path is cut off, so the time from the detection of the pressure rise to the cut off of the path is extremely short, resulting in a response. It has good characteristics. In addition, when the pressure reducing valve 3 fails, the air tank 5 for high pressure air
Since the air flow is cut off, there is no wastage of air, making it extremely economical. From the above, the compressed air decompression device according to the embodiment is extremely safe, economical, and reliable.

[Effect of idea]

As explained above, according to the present invention, there is a pressure reducing valve that reduces the pressure of high pressure air from a high pressure air source, and an air tank that is connected downstream of this pressure reducing valve and stores low pressure air to be supplied to equipment controlled by the air. and a lock valve connected upstream of the pressure reducing valve, the lock valve comprising a high pressure side piston and a detection side piston integrated with the high pressure side piston, and a seat attached to the lower surface of the high pressure side piston. facing a valve seat provided between a first port communicating with the high-pressure air source and a second port communicating with the pressure reducing valve, and connecting the air tank to the upper surface of the detection piston. The structure includes a third communicating port, which eliminates the wastage of compressed air due to repeated operation of the safety valve, and also prevents the pressure in the air tank from rising above the specified pressure even if the safety valve malfunctions. It is possible to provide an economical, highly reliable, and highly responsive compressed air decompression device that can improve performance.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a compressed air system having a conventional pressure reducing device, Fig. 2 is a block diagram showing an embodiment of the present invention, and Fig. 3 is a sectional view showing details of a locking valve in the same embodiment. It is. 3... Pressure reducing valve, 5... Air tank, 12... Locking valve, 17... High pressure side piston, 18... Detection side piston, 20, 21, 22... Mouth, 23...
Seat, 24...valve seat.

Claims (1)

[Scope of utility model registration request] a pressure reducing valve that reduces the pressure of high pressure air from a high pressure air source; an air tank that is connected downstream of the pressure reducing valve and stores low pressure air to be supplied to equipment controlled by the air; and an air tank that is connected upstream of the pressure reducing valve. The lock valve includes a high-pressure side piston and a detection-side piston integral with the high-pressure side piston. A configuration in which a third mouth part is provided on the upper surface side of the detection side piston, facing a valve seat provided between the mouth part and a second mouth part communicating with the pressure reducing valve, and communicating with the air tank. A compressed air decompression device characterized by: