JPH0127310B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION When an emergency occurs in a relatively large-diameter pipe, this invention utilizes the repulsive force of a spring to rapidly close the pipe to prevent damage to the pipe or connected equipment. This relates to emergency shutoff valves.

In order for the emergency shutoff valve to open and close reliably, (1) it must be possible to confirm that the closing operation is performed without fully closing the valve body when it is fully closed; In an emergency, it is necessary to be able to perform an emergency shutoff, and (3) when fluid pressure such as hydraulic pressure is used for opening, holding fully open, and emergency shutoff, it is necessary to be able to confirm the operation of the circuit switching valve.

However, conventional emergency shutoff valves do not meet the above requirements; for example, even though the one disclosed in Publication of Utility Model Publication No. 1341/1983 satisfies the requirements (1) and (2) above, (3)
It did not meet the requirements of

In other words, the system disclosed in the above-mentioned publication has two hydraulic circuits: an emergency cutoff circuit and a separate test operation circuit, so the operation of the valve body can be confirmed by periodically operating the test circuit. However, since this test circuit does not use an emergency switching valve, it is not possible to confirm the operation of the switching valve itself. Therefore, by operating such a test circuit, it cannot be confirmed whether the original emergency cutoff circuit is operating normally.

The object of the present invention is to provide an emergency shutoff valve that solves all of the above three unresolved problems in the conventional emergency shutoff valves.

The present invention will be described below with reference to embodiments shown in the drawings.

In Figs. 1 and 2, 1 is a valve box, and 2 is a valve body fixed to valve stems 3a and 3b that are pivotally supported by the valve body 1. This valve body 2 is rotated by rotating the valve stem 3a. The valve port 4 is opened or closed.

Reference numeral 5 denotes an operating lever, which is fixed to the end of a valve stem 3a that passes through the valve box 1 and projects outside the valve box. One end 6 of this operating lever 5 is connected by a pin 10 to a piston rod 9 of a hydraulic cylinder 8 which is swingably supported on a bracket 7 fixed to the valve box 1, and the other end 11 is swingably supported on the bracket 7. It is connected by a pin 15 to a rod 14 which is pressed by a spring 13 in a pivoted spring case 12. Therefore, the valve body 2 is rotated in the opening direction by the hydraulic cylinder 8 and held fully open, and the spring 13
The repulsive force causes the valve to rotate in the closing direction and remain fully closed.

In Figs. 4 and 2, reference numeral 16 denotes a spring return type hydraulic cylinder with a built-in spring 17. This cylinder 16 is also rotatably supported by the bracket 7, and the piston rod 18 is a hook member rotatably supported by the bracket. It is connected to a connecting link 20 on the opposite side of 19 by a pin 21.

When confirming the closing operation, the hook member 19 is rotated by the hydraulic cylinder 16 to the position shown by the chain line in FIG. It's getting old.

Further, 22 is a pressure oil pipe that sends pressure oil from the oil pressure generator A, and 23 is a return pipe that returns the used oil to the oil pressure generator A. The hydraulic cylinder 8 is a pressure oil pipe 22
A 2-port 2-position switching valve 24 and a throttle valve 25 are connected to each other by a pipe 26, and a return pipe 23, a throttle valve 27, and a directional switching valve 28 are connected to a branch pipe 29. The directional control valve 28 is connected to the pilot pipe 3
0 is connected to a 3-port 2-position switching valve 31, and this switching valve 31 is connected to a pressure oil pipe 22 and a pipe 32, and a return pipe 23 and a pipe 33, respectively.

The hydraulic cylinder 16 is connected to a pipe 35 that connects the pressure oil pipe 22 and the two-port two-position switching valve 34, and is connected to a branch pipe 37 that connects the return pipe 23 and the directional switching valve 36. The directional switching valve 36 is connected to a 3-port 2-position switching valve 39 through a pilot pipe 38, and this switching valve 39 is connected to the pressure oil pipe 22, the pipe 40, and the return pipe 23.
and are connected by pipes 41, respectively. Note that the switching valves 24, 31, 34, and 39 are electromagnetic valves operated by electric signals.

As shown in FIGS. 4 and 5, the directional control valves 28 and 36 have a pilot chamber 42 connected to the pilot pipes 30 and 38, a port 43 connected to the hydraulic cylinders 8 and 16 through branch pipes 29 and 37, and a port 44 connected to the hydraulic cylinders 8 and 16. is connected to the return pipe 23 side, and the piston 46 pressed by the spring 45 connects the pilot chamber 42 and the port 4.
Ports 43 and 44 are communicated or closed by a pressure difference of 3. However, switching from communication to closure and from closure to communication is not performed by a slight change in differential pressure, so a stable state of communication or closure is maintained, and since the port 43 is pressed by the spring 45, the port 43 side is closer to the pilot chamber 42. Even if the pressure is high, it will be closed if the differential pressure is small.

For example, the pressing force f of the spring 45, the pilot chamber 4
If the pressure Pp of 2, the cross-sectional area Ap of the piston 46, the pressure Pb of the port 43, and the diameter area Ab are, the conditions for communication from occlusion are PpAp+f<PbAb→Pp<PpAb/Ap-f/Ap...(1) From communication to occlusion The conditions for this are PpAp+f>PbAp→Pp>Pb−f/Ap (2), and if Ab/Ap=1/1.6, f/Ap=2.5Kg/cm ² and Pb=70 Kg/cm ² , then from occlusion. To communicate, from equation (1), Pp<70/1.6-2.5=41.25 [Kg/cm ² ] To block from communication, from equation (2), Pp>70-2.5=67.5 [Kg/cm ² ], To communicate from blockage: 70−41.25=28.75
[Kg/cm ² ] or more, 67.5− to block the communication
Switching will not occur unless the differential pressure fluctuates by 41.25 = 26.25 [Kg/cm ² ] or more. Further, if Pb-Pp<2.5 [Kg/cm ² ], the blockage is always closed even if Pp is 0.

Next, for convenience, the operation of the embodiment will be explained in five cases depending on the operating state of the valve body 2, that is, when the valve body 2 operates from a fully open position, a fully closed position, and an intermediate position between fully open and fully closed.

(1) When changing from fully closed to fully open: The switching valve 24 communicates the pressure oil pipe 22 and the pipe 26, the switching valve 31 communicates the pressure oil pipe 22, that is, the pipe 32, and the pilot pipe 30, and the switching valve 34 communicates the pressure oil pipe 22 and the pipe 35. When the switching valve 39 is switched to cut off the pressure oil pipe 22, that is, the pipe 40, and the pilot pipe 38, the pressures in the branch pipe 29 and the pilot pipe 30 become almost the same, and the directional switching valve 2
8 is closed, the pressure oil sent from the hydraulic pressure generator A through the pressure oil pipe 22 is transferred to the switching valve 2.
4. Enters the hydraulic cylinder 8 through the throttle valve 25 and pipe 26, overcomes the repulsive force of the spring 13, pushes up the piston rod 9, and releases the actuating lever 5.
By rotating the valve stems 3a, 3b and the valve body 2, the valve body 2 is opened and kept fully open.

(2) For emergency shutoff from full open: The switching valve 24 cuts off the pressure oil pipe 22 and the pipe 26, the switching valve 31 cuts off the pressure oil pipe 22, that is, the pipe 32, and the pilot pipe 30, and the switching valves 34 and 39 are the same as in (1). When the pressure in the pilot chamber 42 of the directional control valve 28 decreases, the oil in the hydraulic cylinder 8 is pressurized by the repulsive force of the spring 13, and the pressure in the port 43 becomes higher than that in the pilot chamber 42. Because the height is higher, ports 43 and 44 communicate with each other, and the oil in the hydraulic cylinder 8 flows through the pipe 2.
6. The valve body 2 is closed because it is discharged to the return pipe 23 via the branch pipe 29.

(3) When moving from fully open to an intermediate position between fully open and fully closed The switching valve 34 switches between the pressure oil pipe 22 and the pipe 3
When the switching valve 39 connects the pressure oil pipe 22, that is, the pipe 40, and the pilot pipe 38, the branch pipe 37 and the pilot pipe 3 communicate with each other.
8 are almost the same, and ports 43 and 44 of the directional switching valve 36 are closed, so the pressure oil passes through the switching valve 34 and the pipe 35 to the hydraulic cylinder 16.
The piston rod 18 is pushed up by overcoming the repulsive force of the spring 17, and the connecting link 2
The hook member 19 connected through 0 is rotated to the position indicated by the chain line in FIG. Thereafter, when the switching valve 24 is switched to cut off the pressure oil pipe 22 and the pipe 26, and the switching valve 31 is switched to cut off the pressure oil pipe 22 and the pilot pipe 30, the valve body 2 is closed as explained in (2). However, at this time, the roller 10a engages with the hook member 19 and prevents the valve body 2 from rotating closed.
It is confirmed that the valve closes at an intermediate position without fully closing.

(4) Resetting when fully opening from the intermediate position From the state of (3), the switching valve 24 is
6 is in communication, the switching valve 31 is switched to communicate the pressure oil pipe 22, that is, the pipe 32, and the pilot pipe 30, and then the switching valves 34 and 39 are switched to cut off the valve body 2 at (1). After starting the opening rotation as described, the hook member 19 also rotates, and the fourth
It is reset to the solid line position in the figure.

(5) When performing emergency shutoff from an intermediate position The switching valve 24 switches between the pressure oil pipe 2 and the pipe 26 from the state of (3).
The switching valve 31 switches to cut off the pressure oil pipe 26 and the pilot pipe 30, and the switching valve 34
shuts off the pressure oil pipe 22 and the pipe 35, and the switching valve 39 shuts off the pressure oil pipe 22, that is, the pipe 40 and the pilot pipe 3.
8, the closing operation of the valve body 2 and the reset rotation of the hook member 19 are started, but at this time, even if the roller 10a and the hook member 19 are engaged, the roller 10a does not rotate. Therefore, the engagement can be easily disengaged, and the valve body 2 can be closed for emergency shutoff.

FIG. 6 shows another embodiment of this invention,
A check valve 5 is used instead of the switching valves 24 and 34 of the above embodiment.
0 and 51 are connected via pipes 52 and 53 between the pipes 26 and 35 and the three-port two-position switching valves 31' and 39'. Since the other parts are the same as those of the previous embodiment, the same parts are given the same reference numerals and the explanation will be omitted.

Since the present invention is configured as described above, the hook member engages with the operating lever at an intermediate position between fully open and fully closed, so the closing operation can be confirmed even if the valve body is not fully closed, and the valve body can be fully opened from this intermediate position. Moreover, when making an emergency cutoff from an intermediate position, even if the hook member and the actuating lever are engaged, the actuating lever rotates, so the engagement can be disengaged and the emergency cutoff can be performed. The same hydraulic circuit is used instead of separate hydraulic circuits as in the past, and this is done through a switching valve built into this circuit, so the operation of this switching valve can be checked at the same time as each valve element is operated. It has excellent effects such as:

[Brief explanation of drawings]

Fig. 1 is a front view of the valve according to the present invention, Fig. 2 is a side view thereof, Fig. 3 is a sectional view taken along the line - - in Fig. 1, and Fig. 4 is a combination diagram of the operating cylinder and hydraulic circuit. , FIG. 5 is a sectional view of the directional control valve, and FIG. 6 is a combination diagram of a cylinder and a hydraulic circuit showing another embodiment. 1...Valve box, 2...Valve body, 3a, 3b...Valve stem, 5...
Operating lever, 7...Bracket, 8...Hydraulic cylinder, 13...Spring, 16...Spring return type hydraulic cylinder, 17...Spring, 19...Hook member, 22...Pressure oil pipe, 23...Return pipe, 24,3
1, 34, 39... switching valve, 28, 36... directional switching valve, 29, 37... branch pipe, 30, 38... pilot pipe, A... hydraulic pressure generator.

Claims (1)

[Scope of Claims] 1. Rotating valve stems 3a and 3b are provided through the valve body 1 and a bracket 7 attached to one side of the valve body, and the valve body 2 is fixed to the inner portion of the valve body. At the same time, an operating lever 5 is fixed to the outside of the valve box, and a hydraulic cylinder 8 is attached to this operating lever to fully open the valve body.
and a biasing member 13 that biases the valve body toward the fully closed side. A hook member 19 is rotatably provided on the bracket 7 to hold the hook member 9 in an intermediate position between fully closed and fully closed, and a hydraulic cylinder 16 drives the hook member 9 to a position where it engages with the operating lever 5 and does not engage with the operating lever 5. A hydraulic pressure generator A is provided which is operatively connected to a biasing member 17 for biasing the position, and has a pressure oil pipe 22 and a return pipe 23. The pressure oil pipe 22 and the hydraulic cylinder 16 are connected by an oil pipe 26, and the pressure oil pipe 22 and the hydraulic cylinder 16 are connected by an oil pipe 35. Also, the return pipe 23 of the hydraulic pressure generator A and the hydraulic cylinder 8 are connected to the return pipe 2.
9, and a switching valve 28 is provided on this oil return pipe 29, and when confirming the closing operation of the valve body 2, the switching valve 34 or the switching valve 39' connects the oil supply pipe 35 and the pressure oil pipe 22. The pressure in the hydraulic cylinder 16 is increased to overcome the biasing force of the biasing member 17, and the hook member 1
9 is rotated to the position where it engages with the operating lever 5, the switching valve 24 or 31' cuts off the oil feed pipe 26 and the pressure oil pipe 22, and the switching valve 28 connects the oil return pipe 29 and the return pipe 23. The actuating lever 5 engages the hook member 19 to fully open and close the valve body 2, and the valve body 2 is closed by the biasing member 13 due to this pressure reduction. When the valve body 2 is held in an intermediate position, and when the valve body 2 is urgently shut off from this intermediate position, the switching valve 34 or 39'
, the pressure oil pipe 22 is switched to be cut off, the hydraulic cylinder 16 is depressurized, and this depressurization causes the biasing member 1 to
7, the hook member 19 is rotated to a position where it does not engage with the operating lever 5, and the valve body 2 is held in the fully closed position by the biasing member 13.