JPH03210609A - Valve device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a valve device that controls the primary pressure of a fluid such as fuel gas to a predetermined secondary pressure.

[Conventional technology]

A conventional valve device of this type uses a control valve to control the primary pressure to a predetermined secondary pressure, and such a valve device is used when supplying fuel gas to a gas burner. In addition, as a publicly known example regarding this invention, Japanese Patent Publication No. 5B-4
There are techniques disclosed in Japanese Utility Model Publication No. 5629 and Japanese Utility Model Publication No. 61-19251.

[Problem to be solved by the invention]

When using a conventional valve device in a gas burner, when the control valve is opened when there is no or little gas on the secondary pressure path side (gas burner side) of the valve device and the control valve is closed, the primary pressure path Since the gas rushes into the gas burner through the secondary pressure path, there are problems in that when ignition occurs at this time, it makes a very loud noise and the flames protrude, which is dangerous. This invention was made in view of the above-mentioned circumstances, and an object thereof is to provide a valve device that can gradually increase the magnitude of secondary pressure.

[Means to solve the problem]

In this invention, a control valve is disposed on the primary pressure path side of the valve port to control opening and closing, and a shutoff valve is provided on the secondary pressure path side of the valve port, and a pressure chamber that applies operating pressure to the shutoff valve has a control valve. It is configured to selectively apply the secondary pressure or the secondary pressure, and further provides a delay time until the pressure chamber reaches the secondary pressure when the pressure in the pressure chamber is switched from the primary pressure to the secondary pressure. This is how it was done.

[For use]

When the control valve is closed, primary pressure is applied to the pressure chamber to close the isolation valve, and then secondary pressure is applied to the pressure chamber by switching from the primary pressure, so that the isolation valve closes the pressure chamber. It is gradually opened with a delay time determined by a time constant determined by the volume and the pressure applied to the pressure chamber, and the shutoff valve is accordingly opened, thereby preventing fluid from entering the secondary pressure path.

【Example】

An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, ■ is the valve body, 2 is the main flow path having a valve port 3 at the boundary between the primary pressure path 21 where fluid flows in and the secondary pressure path 2-2 through which fluid flows out, and 4 is the valve port 3. This is a diaphragm equipped with a control valve 5 for controlling the opening area on the primary pressure side of the diaphragm 4, and the area of the diaphragm 4 is made to match the effective area of the valve port 3. 6 is a diaphragm to which a shutoff valve 7 is attached, which is arranged on the secondary pressure side of the valve port 3; 8 is a pressure chamber formed between the diaphragm 6 and the valve body 1; 9 is an operating pressure path 10 leading to the pressure chamber 8. It is a switching means that switches and connects the flow path 11 leading to the primary pressure path 2-1 and the flow path 12 leading to the secondary pressure path 2-2, and although a three-way valve is shown in the illustrated example, a two-way valve is used. Two valves may be used; however, normally the operating pressure path 10 and the flow path 12 are connected. 13 is a secondary pressure chamber, and this secondary pressure chamber 13 is connected to the secondary pressure path 22 of the main flow path 1 via a communication hole 14. 15 is a diaphragm provided in the secondary pressure chamber 13, and this diaphragm 15 is provided with a valve body 19. 16 is a linkage mechanism provided in the secondary pressure chamber 13. This linkage mechanism 16 includes a lever 16-1 whose one end is rotatably supported on the valve body 1, a lever 16-2 which is rotatably supported at its intermediate portion, and the lever 16-1 and the lever 16.
A link 16-5 connects one end of the lever 16-2 to the diaphragm 4 via a bendable joint 16-3 and 16-4, and a link 16-5 connects one end of the lever 16-2 to the diaphragm 4 via a bendable joint 16-6. It consists of a connecting link 16-7, and the lever 1
6-1 is connected to the valve body 19 through a joint 16-8. 17 is a setting means for setting a control pressure in the linkage mechanism 16. This setting means 17 has a spring 17-
One of the catches 17-2 and 17-3 provided at the upper and lower ends of the lever 17-2, the lower end catch 17-3 is attached to the free end of the lever 16-1, and the upper end catch 17-2 is integrated with a tension rod. 17-4 is configured to protrude from the valve body 1 with a seal member 18 interposed therebetween, and the control pressure is set by changing the screwing amount of the threaded rod 17-4. 20 is a relief hole provided in the secondary pressure chamber 13, 21 is an adjustment hole for adjusting the pressure applied to the switching means 9 from the flow path 12, and 22 is a fixed resistor provided in the flow path 12. , 23 are springs that bias the valve port 3 in the direction of opening. Note that the adjustment screw 21. The fixed resistor 22 and the volume of the pressure chamber 8 constitute a delay time providing means. Next, the operation of the above configuration will be explained. It is now assumed that both the control valve 5 and the isolation valve 7 close the valve port 3. At this time, the switching means 9 connects the flow path 11 to the operating pressure path lO, and the primary pressure of the primary pressure path 2-1 is applied to the pressure chamber 8, thereby maintaining the closing of the shutoff valve 7. has been done. Next, from this state, the switching means 9 is switched to connect the flow path 12 to the operating pressure path IO. As a result, the secondary pressure path 2-
A fixed throttle resistor 22 is connected to the secondary pressure side of 2 through the flow path 12.
and the resistance of the aperture adjustment screw 21 and a composite aperture resistance. Due to the switching of the switching means 9, the pressure in the pressure chamber 8 gradually decreases and approaches the secondary pressure, but the speed of this pressure decrease depends on the magnitude of the composite throttle resistance and the volume of the pressure chamber 8. It is determined according to the delay time due to the determined time constant. As the pressure in the pressure chamber 8 gradually decreases, the cutoff valve 7 gradually opens due to the spring 23. This causes the secondary pressure to rise, causing the diaphragm 15 to rise and the control valve 5 to be controlled via the linkage mechanism 16. The flow rate flowing from the primary pressure path 2-1 to the secondary pressure path 2-2 is adjusted. At this time, even if the secondary pressure is small, the shutoff valve 7 is gradually opened as described above, so fluid does not rush into the secondary pressure path 2-2. Further, the delay time can be adjusted by turning the adjustment screw 21 to adjust the magnitude of the secondary pressure applied from the flow path 12 to the switching means 9. The fluid flowing into the primary pressure path 2-1 is throttled by the control valve 5 and reduced in pressure to a predetermined size, and then enters the secondary pressure path 2-2. In the above state, if the pressure in the secondary pressure path 2-2 increases for some reason, the pressure in the secondary pressure chamber 13 also increases through the communication hole 14. For this reason, diaphragm 1
5 responds to the increased pressure, and this movement of the diaphragm 15 operates the control valve 5 in the closing direction via the linkage mechanism 16, reducing the pressure in the secondary pressure path 2-2. In addition, when the pressure in the secondary pressure path 2-2 decreases, contrary to the above, each of the above parts operates in the opposite direction to the above, and automatically controls the pressure in the secondary pressure path 2-2. do. In this case, since the area of the diaphragm 4 is made to match the effective area of the valve port 3, even if there is a pressure fluctuation in the primary pressure path 21, the control system of the diaphragm 15 of the secondary pressure chamber 13, the linkage mechanism 16, etc. has almost no effect on FIG. 2 shows the main parts of a valve device according to another embodiment of the present invention, in which a recess 8a is provided in the pressure chamber 8, a bellows 24 is provided in the recess 8a, and the bellows 24 is expanded and contracted from the outside. By providing an adjustment screw 25 for
This constitutes a delay time providing means. According to the above configuration, by turning the adjustment screw 25, the entire volume of the pressure chamber 8 including the recess 8a can be changed. Therefore, the pressure in the pressure chamber 8 is reduced to 1 by the switching means 9.
When switching from the secondary pressure to the secondary pressure, the delay time until the pressure in the pressure chamber 8 reaches the secondary pressure can be adjusted.

【Effect of the invention】

According to this invention, a control valve is disposed on the primary pressure path side of the valve port to control opening and closing, and a shutoff valve is provided on the secondary pressure path side of the valve port, and a pressure chamber that applies operating pressure to the shutoff valve is connected to the control valve. The primary pressure path It is possible to prevent fluid from entering the secondary pressure path, the opening speed of the shutoff valve can be arbitrarily adjusted, and it is possible to obtain a valve device that is small and compact overall. The effect of this can be obtained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view showing a valve device according to one embodiment of the invention, and FIG. 2 is a cross-sectional side view showing essential parts of a valve device according to another embodiment of the invention. 3 is a valve port, 5 is a control valve, 7 is a cutoff valve, 8 is a pressure chamber,
9 is a switching means, 10 is an operating pressure path, 11° and 12 are flow paths,
15 is a diaphragm, 16 is a linkage mechanism, 19 is a valve body, 24 is a bellows, and 21.25 is an adjustment screw.

Claims (1)

[Claims] a valve port provided between a primary pressure path and a secondary pressure path in the main flow path of fluid; a control valve that opens and closes the valve port from the primary pressure path side; and a control valve that opens and closes the valve port from the primary pressure path side; a shutoff valve that opens and closes from the pressure of the primary pressure path, a response means that controls the control valve in response to the pressure of the secondary pressure path, a pressure chamber that operates the shutoff valve, and a pressure chamber that controls the pressure of the primary pressure path or a switching means for selectively applying pressure to the secondary pressure path; and a delay time required for the primary pressure in the pressure chamber to become the secondary pressure when the switching means is switched from the primary pressure path to the secondary pressure path. and a delay time applying means for giving.