JPS62110083A - Double safety valve - Google Patents

Abstract

PURPOSE:To ensure a double safety function without causing biting by connecting each of two check valves, arranged in two fluid chambers to check the flow to the outlet port, to another fluid chamber other than the relevant one so as to receive an opening dynamic pressure. CONSTITUTION:Now, considering the case where the first valve stem 17 is not operated, but the second valve stem 20 is operated, since the first fluid chamber 8 is cut off from a supply chamber 5 and is communicated with an exhaust chamber 10, the second check valve 38 closes the opening part 7 by the fluid pressure in the second fluid chamber 9 communicated with the supply chamber 5. Accordingly, the fluid in the second chamber 9 is not supplied to an exhaust port 3. Since the first check valve 34 releases the opening part 6 by the pilot pressure from the second fluid chamber 9, the fluid for an actuator is discharged via an opening part 6. The same is the case where only the second valve stem is put into a nonoperating condition.

Description

[Detailed Description of the Invention] Technical Field The present invention has two valve stems inside, and when one valve does not operate or has a delay in operation, it detects an abnormality and turns off the power for valve switching. This relates to a double safety valve that has the following functions.

Prior Art As a safety valve that is connected between an actuator and a pressure source and drains the actuator's fluid except when the valve is operating normally to prevent excessive force from being applied to the actuator, it is used, for example, in a press operation. As a safety valve for the system, it is known, for example, to use a double-type 3-port valve in which two sets of valve bodies are arranged side by side in one main body, as disclosed in Japanese Patent Application Laid-Open No. 56-46.
It is known from the publication No. 170.

Problems with the prior art In the prior art described above, in order to stop the fluid supply when one valve in the main body does not operate, it is necessary to form an X-shaped flow path between the two valves, and the structure The problem was that it became complicated. Furthermore, each of the two valves has a spool valve element and a poppet valve element arranged in a skewer shape on one valve stem, and solid powder gets caught in the gap between the spool valve element and the main body. There was a problem in that it caused The quality of the fluid used was therefore limited.

Means for Solving the Problems The present invention solves the above problems by providing a supply chamber connected to a supply port in the main body, and a first fluid chamber and a second fluid chamber respectively connected to the outlet port via check valves. , a discharge chamber connected to the discharge port, and each of the two fluid chambers communicates with the supply chamber and the discharge chamber by two coaxially formed openings, and each has one individual fluid chamber. A valve stem actuated by the pilot valve passes through the valve stem, and the valve stem has two
The two check valves are configured to open the opening when one poppet valve is seated in the opening, and the two check valves are configured to open the opening. The problem was solved by a double safety valve, which is formed to block the flow to the port, and is connected to a fluid chamber other than the fluid chamber that opens and closes to receive the opening dynamic pressure.

The structure and operation of the present invention will be explained in detail based on the embodiment shown in the drawings.

In FIG. 1, the main body 1 has a supply port 2, an outlet port 3, and a discharge port 4. A supply chamber 5 is connected to the supply port 2 and a first opening 6 is connected to the outlet port 3.
A fluid chamber 8 and a second fluid chamber 9 are connected via the second opening 7 . A discharge chamber IO is connected to the discharge port 4.

The first fluid chamber 8 is connected to the supply chamber 5 through a third opening 11 and the discharge chamber 10 through a fourth opening 12, while the second fluid chamber 9 is connected to the supply chamber 5 through a fifth opening 13. and is connected to the discharge chamber IO through the sixth opening portion 14. The third opening 11 is formed coaxially with the first opening 12, and the fifth opening I3 is formed coaxially with the sixth opening 14.

The first poppet valve body I5 seated in the third opening 11 and the fourth poppet valve body I5 seated in the third opening 11
A second poppet valve body 16 that seats in the opening 12 is formed in the first valve stem 17 and a third poppet valve body 16 that seats in the fifth opening 13 is formed in the first valve stem 17 .
A poppet valve body 18 and a fourth poppet valve body 19 seated on the sixth opening portion 14 are formed on the second valve stem 20 . 1st
When the poppet valve body 15 and the third poppet valve body 18 are seated in the openings, the second poppet valve body 16 and the fourth poppet valve body 19 open their respective openings, and conversely, the second poppet valve body 16 and the fourth poppet valve body 19 open their respective openings. When the fourth poppet valve body 19 is seated in the opening, the first poppet valve body 15 and the third poppet valve body 18 are each opened.

A first piston 21 having a larger pressure-receiving area than the first poppet valve body 15 and a guide rod 22 of the first valve stem are formed on the first valve stem 17, and the first piston 21 has a main body! the first of
It is slidably guided in a cylinder part 23, and the guide rod 22 of the first valve stem is slidably guided in a second cylinder part 24 of the body l. Similarly, the second valve stem 20 has a second poppet valve body 18.
A first piston 25 having a larger pressure-receiving area and a guide rod 26 for the second valve stem are formed, and the first piston 25 is slidably guided by a third cylinder part 27 of the main body 1, and a guide rod 26 for the second valve stem is formed. The guide rod 26 is slidably guided in the fourth cylinder part 28 of the main body 1 .

The first cylinder part 23 is connected to the first cylinder by the pilot flow path 29.
A third valve connected to the outlet port of the pilot solenoid valve 30
The cylinder portion 27 is connected by a pilot passage 31 to an outlet port of a second pilot solenoid valve 32. The artificial port of each pilot solenoid valve 30, 32 communicates with the supply chamber 5 via a channel 41, and the second cylinder part 24 as well as the fourth cylinder part 28, respectively, via a channel 42, 43.

A first check valve 34 has a piston 35 with a poppet valve body 33 seated in the first opening 6 and blocking flow from the first fluid chamber 8 to the outlet port 3 .

The piston 35 is located in a pilot cylinder chamber 36 of the main body l.
slidingly guided. A second check valve 38, which likewise seats in the second opening 7 and browns the poppet valve body 37 blocking flow from the second fluid chamber 9 to the outlet port 3, has a piston 39 and has a screw! - The cylinder 39 is slidably guided into the pilot cylinder chamber 40 of the main body 1. The poppet valve body 33 side of the pilot cylinder chamber 36 communicates with the second fluid chamber 9 via the flow path 44, and the opposite side is open to the outside and is connected to the pilot cylinder chamber 36.
The poppet valve body 37 side of the chamber 40 communicates with the first fluid chamber 8 via a flow path 45, and the opposite side is open to the outside. Further, the poppet valve 33 side of the piston 35 is larger than the pressure receiving area of the poppet valve 33, and similarly, the poppet valve 33 side of the piston 40 is larger than the pressure receiving area of the poppet valve 33.
7 side is configured to be larger than the pressure receiving area of the poppet valve 37.

The first fluid chamber 8 and the second fluid chamber 9 each have a flow path 46.4.
It is connected to the monitor device M via 7.

FIG. 2 schematically shows this device based on JIS symbols. The operation of this device will be explained below.

Normally, the pilot valves 30, 32 are in an inoperative state;
1st. The fluid in the third cylinder part 23.27 is discharged to the outside, and the fluid in the third cylinder part 23.27 is discharged to the outside. Since the fourth cylinder part 24.28 is under fluid pressure, openings 11.13 are closed and opening 1.
2.14 will be released.

Therefore, the fluid supply to the fluid chamber 8.9 is stopped and the fluid chamber 8.9 is stopped.
．． 9 communicates with the discharge chamber IO, so that the fluid of the actuator connected to the outlet port 3 opens the check valve 34, 38 and is discharged from the discharge port 4.

When the pilot valve 30.32 is actuated, the piston 21
．． Since the poppet valve 25 has a larger pressure receiving area than the poppet valve 15.18, it is moved from the position shown to close the openings 12 and 14 and open the opening 11.13. The supply chamber 5 thus communicates with the fluid chamber 8.9, and the pressure in the fluid chamber 8.9 causes the check valve 34.38 to open the opening 6.7 and supply fluid to the actuator.

Now! If we look at the case where the valve stem 1117 does not operate and the second valve stem 20 operates, the first fluid chamber 8 is cut off from the supply chamber 5 and communicates with the discharge chamber IO, so the second check valve 38
Pilot fluid pressure does not operate. Second check valve 38
The opening 7 is closed by the fluid pressure of the second fluid chamber 9 communicating with the supply chamber 5, so that the fluid in the second fluid chamber 9 flows through the outlet port 3.
is not supplied. The first check valve 34 opens the opening 6 by the pilot pressure from the second fluid chamber 9, so that the actuator fluid is discharged through the opening 6.

The same applies when only the second valve stem 20 becomes inactive. Therefore, when one valve stem is inactive, the outlet port 3 does not receive fluid supply and communicates with the discharge port 4, so there is no risk of fluid being forcibly supplied to the actuator.

When one of the valve stems does not operate, a difference is generated in the pressure applied to the monitor M, and a malfunction is detected. This causes the actuator to stop.

As shown in FIG. 3, the arrangement of the poppet valve body 33 and piston 35 of the first check valve 34 can be reversed to the arrangement shown in FIG. 1. Although not shown in the drawings, the second reverse valve 38 can be formed in the same manner.

According to the present invention, a double safety valve can be constructed with a simple structure, and since a poppet valve is used and a spool valve is not used, even if solid powder is contained in the fluid, it can be prevented from being caught. I was able to resolve the issue that occurred.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a double safety valve according to the present invention, FIG. 2 is a schematic explanatory diagram of the structure of the double safety valve according to the present invention, and FIG. 3 is a cross-sectional view of a modification of the first check valve. It is a diagram. ■...Body 2...Supply port 3...
- Outlet port 4... Discharge port 5... Supply chamber 8... First fluid chamber 9... Second supply chamber 10... Discharge port 11, +2.13.14.
...Opening 15, +6.18.19...Poppet valve body 17.20
...Stem 34.38...Check valve r2 -+,

Claims (1)

[Claims] (1) In a double safety valve that has two valve stems inside the main body and can detect an abnormality when one valve does not operate or is delayed in operation, a supply chamber connected to the supply port in the main body. A first fluid chamber and a second fluid chamber are respectively connected to the outlet port via a check valve, and a discharge chamber is connected to the discharge port, and the two fluid chambers are coaxially arranged. Two openings are formed that communicate with the supply chamber and the discharge chamber, each of which is pierced by a valve stem actuated by one individually piloted valve, the valve stem having two poppet discs. , the one poppet is configured to open the opening when the other poppet is seated in the opening, and the two check valves are configured to prevent flow to the outlet port. 1. A double safety valve, which is formed and connected to a fluid chamber other than the fluid chamber that opens and closes to receive an opening dynamic pressure.