JPH0650446A - Totally closed seal mechanism of emergency shutdown valve - Google Patents

Abstract

PURPOSE:To save the weight of the counter weight, and secure the sealing property while improving the operability and safely by generating a large torque when the valve element is closed by the self-weight of a counter weight in the emergency shut-down operation, and thereby the valve element being strongly bit into the rubber sheet. CONSTITUTION:A cylinder 15 having a spring to give the pushingly pressing force in the closing direction to the valve body 5 which is closed by the self- weight of a counter weight 7, in the totally closed position, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a butterfly or the like, and is an emergency system constructed so that a valve body is closed by the weight of a counterweight so as to automatically cut off a flow path in an emergency. The present invention relates to a fully closed sealing mechanism of a shutoff valve.

[0002]

2. Description of the Related Art Conventionally, in a general emergency shutoff valve of this type, a counterweight is connected to the valve body via a lever for closing the valve body in an emergency, and the counterweight is generated by its own weight. The valve body is configured to bite and closely adhere to the rubber sheet on the valve box side at the fully closed position to seal the flow path via the generated torque.

[0003]

However, according to the conventional fully closed seal mechanism for the emergency shutoff valve having the above-mentioned structure,
It is necessary to use a heavy counterweight in order to forcefully bite the valve body in the fully closed position into the rubber sheet to completely seal the flow passage in the case of emergency shutoff. That is, for example, in a butterfly valve or the like, an unbalanced torque in the closing direction works at the intermediate opening, so that a counterweight of a large weight is not necessary, but when fully closed, the valve body is bitten into a rubber sheet to seal. A heavy counterweight is required only to ensure the quality.
When the weight of the counterweight increases in this way, the cylinder used for the opening operation of the valve body also becomes larger. Further, when a heavy counterweight is used, there is a problem that particularly strict control in terms of safety is required.

The present invention has been made to solve the above-mentioned conventional problems. The counterweight is lightened to improve the operability and safety, and at the same time, the sealing performance in the emergency cutoff is sufficiently improved. It is an object of the present invention to provide a fully-closed sealing mechanism for an emergency shutoff valve that can be secured in the.

[0005]

In order to achieve the above object, a fully closed sealing mechanism for an emergency shutoff valve according to the present invention has a counterweight via a lever on a valve body which is set to a predetermined opening position by cylinder drive. In the fully closed sealing mechanism of the emergency shutoff valve, the valve body is closed by its own weight in an emergency in the event of an emergency. The spring-loaded cylinder for applying a pressing force to the closing direction of the valve body is provided to the valve body.

[0006]

According to the fully closed seal mechanism of the emergency shutoff valve having the above structure, when the valve body closed by the weight of the counterweight is in the fully closed position in an emergency, it is closed to the valve body via the spring-loaded cylinder. Since the pressing force in the forming direction is applied, the valve element comes into close contact with the rubber sheet on the valve box side with a large torque. In other words, while using the counterweight that is light in weight, the valve body can be squeezed into the rubber sheet with a large torque at the time of closing to ensure a sufficient sealability in an emergency cutoff.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4, reference numeral 1 is a cylindrical valve box having a stainless steel valve box seat 1a. Reference numerals 2 and 3 denote a pair of left and right bearings fixed to the valve box 1, and both bearings 2 and 3
A valve body 5 is fixed to a valve shaft 4 supported by the.

Reference numeral 6 denotes a lever whose base end portion 6a is connected to the valve shaft 4 side, and has at its tip end portion 6b a counterweight 7 for closing the valve body 5 by its own weight at the time of emergency interruption.
Are fixed with bolts 8 or the like. Reference numeral 9 is a hydraulic cylinder which is arranged in a vertical posture and whose base end portion 9a is pivotally supported by a support bracket 11 via a pin 10 and a tip of a piston rod 12 of which is supported by a pin 13. Is connected to the lever 6, and the valve body 5 is set to the fully open position shown by the chain line in FIG. 2 through the lever 6 during normal use. Reference numeral 14 is a lock mechanism for holding the valve body 5 in the fully closed and open position.

Reference numeral 15 is a spring-loaded cylinder which is attached to the stand 16 so as to face the counterweight 7. This spring-loaded cylinder 15 is, for example, as shown in FIG. 3, a piston 19 fitted in a cylinder body 17 and urged by a spring 18 to exert a spring force in the axial direction.
The rod 20 is fixed to the rod 20, and the pressing member 21 connected to the tip of the rod 20 applies a pressing force to the valve body 5 in the closing direction via the counter weight 7 in the fully closed position at the time of emergency interruption. It is supposed to do. 22, 23
Is a hydraulic port, 24 is a guide rod connected to the pressing member 21 via a connecting member 25, and 26 and 27 are guide rods 2.
4 is a member for setting a stroke attached to No. 4. In the fully closed seal mechanism of the emergency shutoff valve configured as described above, during normal use, the hydraulic cylinder 9 is operated to rotate the lever 6 by the piston rod 12 to rotate the counterweight 7.
Is displaced to the position indicated by the chain line in FIG. 2, the valve body 5 is set to the fully open position. When the valve body 5 is set to the fully open position, the lock mechanism 14 holds it and the hydraulic cylinder 9 is switched to the free state. On the other hand, at this time, the spring-loaded cylinder 15 drives the piston 19 against the spring force of the spring 18 by hydraulic pressure to retract the pressing member 21.

In the event of an emergency, the lock mechanism 1
When the lock of 4 is released, the counterweight 7 is displaced downward from the chain line position to the solid line position by its own weight, and accordingly, the valve body 5 is also moved to the fully closed position via the lever 6. At this time, since the hydraulic cylinder with spring 15 operates and the piston 19 is driven forward by the spring force, the pressing member 21 moves forward and the pressing force in the closing direction is applied to the valve body 5 via the counter weight 7. Give. For this reason, the rubber sheet 5a of the valve body 5 bites into the valve box sheet 1a on the valve box 1 side with a large torque and comes into close contact therewith.

In this way, a large torque can be obtained for the bite of the valve body 5, so that a lightweight counterweight 7 can be used. In addition, the hydraulic cylinder 9 can be made smaller and have a smaller capacity than when the counterweight 7 has a large weight, and the safety can be easily managed.

[0012]

As described above, according to the present invention, when the valve body, which has been closed by the weight of the counterweight in an emergency, is in the fully closed position, the spring-loaded cylinder pushes the valve body in the closing direction. Since the pressure is applied, it is possible to make the valve body bite into the rubber sheet on the valve box side with a large torque to be brought into close contact with it. Therefore, the weight of the counterweight can be reduced, and the operability and safety can be improved, while the effect of being able to secure the sealing performance in an emergency is achieved.

[Brief description of drawings]

FIG. 1 is a front view showing a fully closed seal mechanism of an emergency cutoff valve according to an embodiment of the present invention applied to a butterfly valve.

FIG. 2 is a side sectional view showing a fully closed seal mechanism of the emergency shutoff valve in the embodiment.

FIG. 3 is a half sectional view showing a hydraulic cylinder with a spring in the same sealing mechanism.

FIG. 4 is an enlarged view of part A in FIG.

[Explanation of symbols]

 5 Valve body 6 Lever 7 Counter weight 9 Cylinder 15 Cylinder with spring

Claims (1)

[Claims] 1. A counterweight is connected to a valve body, which is set at a predetermined opening position by driving a cylinder, via a lever, and the valve body is closed by its own weight in an emergency. In the emergency shut-off valve full-closed sealing mechanism, a spring-loaded cylinder that applies a pressing force in the closing direction of the valve body is provided to the valve body that is closed to the fully closed position via the counterweight in the event of an emergency. A fully closed seal mechanism for emergency shutoff valves.