JPS6141003Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a cutoff valve that is installed in a gas supply pipe of a gas appliance, etc., to cut off the gas supply in the event of a gas leak, especially on the secondary side. This invention relates to a seal valve that has the function of checking for gas leakage.

Generally speaking, it is desirable for this type of cut-off valve to have a secondary side leak check function when the valve is reopened after the cut-off operation. To prevent dangers such as explosions,
The secondary side leak check function described above is essential.

This idea was made in view of the above circumstances,
The purpose of this system is to automatically detect whether or not there is a leak on the secondary side of a gas supply pipeline, and to automatically shut off the temporary side in the event of a leak. do.

An embodiment of this invention will be described below based on the drawings. The emergency valve opening shown in Figures 1 and 2 is as follows:
It basically consists of three parts: an actuator part A, a valve part B, and a leak detection part C.

The actuator section A is a controller D which will be described later.
An electromagnetic pump 3 operates only when a drive signal is input from the tank 1 (see Fig. 4), and pumps the hydraulic oil in the tank 1 to the pressure chamber 2. The displacement is transmitted to the valve part B via the rod 5.

Further, when the responsive body 4 is displaced to a predetermined position, the micro switch 6 detects this and sends a signal to the controller D, and the supply of the drive signal to the electromagnetic pump 3 is stopped.

This state is maintained until the normally closed valve 7 is opened by an external signal. When the valve is opened, the pressure within the pressure chamber 2 is released and the responsive body 4 returns to its original position by the action of the spring 8.

The valve part B includes an inlet passage 11 and an outlet passage 12 arranged substantially coaxially, an oblique valve seat 13 provided at the boundary between the two, and a valve body 15 that opens and closes a port 14 of the valve seat 13. has.

The valve body 15 is supported by one end of a lever 17 that is rotatably supported around a support shaft 16, and the other end of this lever 17 supports a roller 18 that comes into contact with the tip of the rod 5. , the lever 17 is moved clockwise in FIG.
In other words, the valve body 15 is biased in a direction to press against the valve seat 13.

Therefore, when the lever 17 is not receiving any pressing force from the rod 5, the valve body 15 is in close contact with the valve seat 13 and closes the port 14, but due to the displacement of the rod 5, the lever 17 is moved to the second position. When rotated counterclockwise in the figure, it moves to the position shown by the imaginary line in Figure 2,
Open port 14.

The inlet passages 11 and 12 are arranged coaxially,
Moreover, since the valve seat 13 is inclined with respect to this axis, the resistance acting on the gas flowing from the inlet passage 11 to the outlet passage 12 is extremely small.

The illustrated valve seat 13 and valve body 15 each have a double structure in order to obtain redundant operation.

That is, the valve seat 13 has a first valve seat arranged on a concentric circle.
It consists of a valve seat 13a and a second valve seat 13b, and the valve body 15 has a first valve seat 13a that contacts the first valve seat 13a.
The valve 15a and the second valve 1 that abuts on the second valve seat 13b
It consists of 5b.

The first valve 15a is supported at the tip of a shaft 22 attached to the lever 17 so that its direction can be changed within a predetermined range, and the second valve 15b is supported in the axial direction within a predetermined range by the first valve 15a. The first valve 15a is supported so as to be movable and biased by a spring 23 in a direction away from the first valve 15a.

Furthermore, the leak detection section C has a bypass passage 31 that connects the inlet passage 11 and the outlet passage 12 by bypassing the port 14 that is opened and closed by the valve body 15.

Inside this bypass passage 31, a governor 32, a solenoid valve 33, an orifice 34, and a pressure detector 35 are installed.
is provided.

The pressure sensor 35 in the illustrated example has a bypass passage 35
a diaphragm 36 that is displaced according to the internal pressure;
It consists of a reed relay 38 which generates an output signal when a magnet 37 attached to the center of the diaphragm 36 reaches a predetermined position. In addition,
As a means for detecting the displacement of the diaphragm 36,
A micro switch can also be used.

The specific structure of the electromagnetic pump 3 is shown in FIG.
Two mutually independent coils 53 and 54 are arranged on the outer peripheral surface of the support passage 52 to which the cap 51 is attached.
is fixed therein, and a stator 55 and a plunger 56 each having a cylindrical shape are housed inside.

The plunger 56 is held at a predetermined position within its movement range by two balance springs 57 and 58 that act in opposite directions. It has a cylindrical body 61 that protrudes into the center hole.

Further, the stator 55 is also provided with a check valve 62.

Further, a sleeve 63 that forms an annular passage with the support cylinder 52 is fixed to the stator 55, and a second plunger 64 that supports the normally closed valve 7 is disposed within the sleeve 63 in the axial direction. Stored in a movable manner.

This plunger 64 is urged to close one end of a passage 66 provided at its center by pressing the normally closed valve 7 into contact with the tip of the member 65, and is fixed to a passage 67 formed around this member 65. child 55
It has a plurality of through holes 68 that connect the center hole of the main hole.

When the coil 54 is de-energized, the plunger 64 is held in a position where the normally-closed valve 7 is pressed against the member 65, and when the coil 54 is energized, the plunger 64 moves against the biasing force to close the normally-closed valve. Open 7,
The passage 66 is communicated with a passage 67.

The passage 67 communicates with the tank 1 side, and the annular passage between the support cylinder 52 and the sleeve 63 communicates with the pressure chamber 2 side via a passage 69.

The coil 54 with the normally closed valve 7 closing one end of the passage 66
In the de-energized state, when the coil 53 is energized, the plunger 56 reciprocates, whereby the hydraulic oil in the passage 67 connected to the tank 1 side is force-fed to the passage 69 side, and the hydraulic oil in the pressure chamber 2 is Pressure increases.

At this time, the hydraulic oil enters the center hole of the stator 55 from the passage 67 through the through hole 68 and the check valve 6
When the check valve 59 opens, it flows into the cylinder body 61 through the cylinder body 60, and then into the cap 51 when the check valve 59 opens. (not shown)
The liquid flows within the annular passageway between the support tube 52 and the sleeve 63 to reach the passageway 69 .

Further, when the coil 54 is energized, the plunger 56 is attracted toward the stator 55, and the normally closed valve 7 is separated from the member 65, so that the passage 6
9 and 67 communicate with each other via a passage 66, and the pressure within the pressure chamber 2 is released.

The operation will be explained with reference to FIG. 4, which schematically shows the configuration of this emergency shutoff valve.

When a reset command is given to the controller D with the valve body 15 in the closed position, the controller D closes the solenoid valve 3.
An operating signal is supplied to 3 to cause it to open.

Gas in the inlet passage 11 thereby flows through the bypass passage 31 and into the outlet passage 12. At this time, if there is no damage to the piping connected to the outlet passage 12 and all the appliance plugs are closed, the outlet passage 12
The secondary pressure inside 2 increases.

This increase in secondary side pressure is detected by the pressure detector 35, and when this detected value reaches a predetermined value (set value), the reed relay 38 sends an output signal to the controller D.

After the leak check of the secondary side pressure is performed in this way, the controller D supplies a drive signal to the electromagnetic pump 3 via the micro switch 6, and by operating the electromagnetic pump 3, the inside of the tank 1 is of hydraulic fluid is pumped into the pressure chamber 2. At this time, since the normally closed valve 7 is closed, the pressure within the pressure chamber 2 increases.

This increase in pressure within the pressure chamber 2 causes displacement of the responsive body 4 and the rod 5, which causes the lever 17 to rotate in the counterclockwise direction in FIG. Leaving the seat 13, the inlet passage 11 communicates with the output passage 12. This state is
It is held until an abnormality such as a gas leak is detected.

When an abnormality such as a gas leak or an earthquake is detected, a signal from a normal detector (not shown) is sent to the controller D as a shutdown command, which causes the controller D to shut down regardless of the state of the micro switch 6. While cutting off the signal supply to the electromagnetic pump 3,
An opening operation control signal is supplied to the normally closed valve 7.

As a result, when the normally closed valve 7 opens, the pressure in the pressure chamber 2 is instantly released, so the lever 17 rotates clockwise in FIG. 4 under the action of the spring 21, and the valve body 15 Entrance passage 11 in close contact with seat 13
The communication between the valve and the outlet passage 12 is then cut off.

In this state, when a reset command is given to controller D from the outside, the above-mentioned reset operation will be repeated if there is no gas leak on the secondary side.
If there is a leak due to damage to the piping or forgetting to tighten the appliance stopper, a signal from controller D will activate solenoid valve 3.
3 is opened, the pressure on the outlet passage 12 side does not increase, so no output signal from the reed relay 38 is generated.

If the pressure within the outlet passage 12 does not rise to the set value even after a set time (for example, about 30 seconds) has elapsed since the above reset command was given, the controller D stops the subsequent sequence and turns off the solenoid valve. Close 33.

Therefore, if there is a leak on the secondary side, valve body 1
5 will not be opened.

In the emergency valve disconnection structured in this way,
When resetting after the shrinking operation, first open the solenoid valve 33 to send the gas in the inlet passage 11 to the outlet passage 12 side through the bypass passage 31, and if there is no leak on the outlet passage 12 side, Although the pressure within the outlet passage 12 increases within the set time, if a leak were to occur, the time required for the pressure within the outlet passage 12 to rise to the set value would be increased.

Therefore, the pressure (P ^* ) at which the pressure detector 35 detects a rise in pressure and generates an output signal is set to a predetermined value, and the pressure detector 35 is activated within a set time after the solenoid valve 33 opens. If an output signal is generated, it can be determined that there is no leak.

Here, the opening area of the outlet passage 12 is (S _OR ),
Assuming that the opening area causing the leak is (S _R ) and the pressure in the inlet passage 11 is (Pin), the pressure (P∞) in the output passage 12 at the time of the maximum allowable leak is expressed by the following equation.

P∞= _SOR2 ^/ _SOR2 × ^SOR2 ×Pin... ₍ 1) Therefore, the operating pressure (P ^* ) of the pressure detector ³⁵ is set to a value somewhat higher than (P∞). If there is a leak that exceeds the allowable amount, it will be reliably detected.
is limited to certain cases.

However, the gas supply pressure is generally 50 to 200 mm.
Since it usually fluctuates over a wide range of up to H ₂ O, the operating point of the pressure detector 35 and the magnitude of the leakage amount may not correspond.

However, in this invention, the governor 32 is inserted into the bypass passage 31 to prevent pressure fluctuations in the inlet passage 11 from reaching the outlet passage 12.
If there is a leak exceeding the set amount on the outlet passage 12 side, the pressure detector 35 will not malfunction in that it will output an output within the set time.

As described above, according to this invention, when the secondary side pressure value detected by the pressure detector is equal to or higher than the set value, the pressure detector outputs a valve opening command signal to the controller. It can be guaranteed that there is no leakage of the secondary pressure. If there is a leak, the detected secondary pressure value will not rise to the set value, and the valve body will remain closed after the set time has elapsed when it is below the set value. Since the solenoid valve in the bypass passage is closed by the output signal from the controller, even if there are pressure fluctuations in the inlet passage, the outlet passage side can be reliably cut off in an emergency in the event of the above-mentioned leak. A high degree of safety can be obtained as a closed valve.

Further, since the governor is provided in the bypass passage where the flow rate is small, it may be small, and there is an advantage that the entire structure can be made compact.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view showing the main parts of an emergency shutoff valve according to an embodiment of the invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig. 3 is a diagram of an electromagnetic pump. The vertical sectional view and FIG. 4 are control circuit diagrams for the emergency valve opening. A...actuator, D...controller,
11... Entrance passage, 12... Exit passage, 14...
Valve seat port, 15... Valve body, 31... Bypass passage, 32... Governor, 35... Pressure detector.

Claims (1)

[Scope of utility model registration request] A valve body that opens and closes a valve seat port provided between an inlet passage and an outlet passage, an actuator that opens and closes the valve body, and a valve body that bypasses the valve seat port and connects the inlet passage and the outlet passage. a bypass passage; a solenoid valve and a governor provided in the bypass passage; a controller that receives a reset signal to control the opening and closing of the valve body and the solenoid valve; A pressure detector that detects the secondary pressure of the valve, outputs a valve opening command signal for the valve body to the controller when the detected value is equal to or higher than a set value, and does not output the valve open command signal when the detected value is equal to or lower than the set value. and
The controller is characterized in that it outputs a valve closing signal to the solenoid valve when the secondary side pressure is below a set value after a set time has elapsed when the valve body is closed and the solenoid valve is open. Denunciation.