JPH09144899A - Butterfly valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent beforehand any water hammer produced by the free rotation of a valve body. SOLUTION: A fluid pressure cylinder 14 by which an anchor pin 15 is advanceted/retreated in parallel with the axial center direction of a valve rod 2a is installed on the suitable place near to the valve rod 2a of a valve box 1 and lock plate 17 formed plural lock holes 16 in a periphery direction at a specified interval while facing to an anchor pin 15 is stuck on the valve rod 2a and a limit switch 20 for detecting the position of valve rod 2a dislocated for a drive shaft 7a is installed and also limit switch 22 for detecting that the position of a stand 6 is shifted for the valve box 1 is installed. A fluid pressure cylinder 14 is driven based on the detection signals of respective limit switches 20, 22 and the anchor pin 15 is inserted in either one of lock holes 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a butterfly valve capable of preventing a water hammer caused by free rotation of a valve body.

[0002]

2. Description of the Related Art An example of a butterfly valve is shown in FIG. This is an upper bearing in which a valve element 2 is arranged to be openable and closable in a valve box 1, and a valve rod 2a of the valve element 2 is rotatably supported above and below the valve box 1 via bushes 3 and 4. Part 1
a and the lower bearing portion 1b are fixed by fastening bolts 5c and 5d. A valve drive device 7 having a speed reducer is fastened by a fastening bolt 5b on a stand 6 fixed on the upper flange portion 1c of the valve box 1 by a fastening bolt 5a, and is attached to a lower end portion of a drive shaft 7a of the valve drive device 7. The valve rod 2 is attached to the boss portion 8 provided.
The upper end of a is fitted, and the boss 8 and the valve rod 2a
A valve body 2 which is connected to the upper end of the lower bearing 1b by a key 9 and closes the bottom opening of the lower boss portion 1d of the valve box 1.
The upper head of the position adjusting fastening bolt 10 is rotatably connected to the lower surface of the valve rod 2a by the pressing plate 11, and the lock nut 12 screwed to the position adjusting fastening bolt 10 of the valve body 2 is attached to the lower surface of the lower bearing 1b. Abutted.

Conventionally, as a preventive measure against a water hammer caused by free rotation of the valve body 2, a fastening bolt 5a for fastening the valve box 1 and the stand 6 and a fastening bolt 5b for fastening the stand 6 and the valve drive device 7 and the like. As a concrete measure, (1) confirmation of looseness of the fastening bolts 5a, 5b by the wire, (2) fastening bolts 5a,
Torque management when fastening 5b, (3) fastening bolts 5a, 5
After tightening b, insert a matching mark to attach the bolts 5a, 5b.
Checking for looseness.

[0004]

SUMMARY OF THE INVENTION In the above conventional configuration,
Insufficient measures to prevent water hammer,
There is a possibility that the valve rod 2a, the fastening bolts 5a and 5b, the stand 6, the key 9 and the like may be broken due to corrosion and the valve body 2 may rotate freely to cause a water hammer.

In view of the above problems, it is an object of the present invention to provide a butterfly valve capable of preventing a water hammer caused by free rotation of a valve body.

[0006]

In order to achieve the above object, the present invention provides a drive shaft of a valve drive device on a stand, in which a valve element is openably and closably arranged in a valve box and fixed on the valve box. And a valve rod of the valve element are concentrically connected to each other, and by driving the valve driving device, the valve element is opened and closed through the drive shaft and the valve rod. A pin withdrawal drive device for withdrawing and retracting the anchor pin in parallel with the axial direction of the valve rod is provided at a proper position in the vicinity of the valve rod, and a plurality of lock holes are provided facing the anchor pin at predetermined circumferential intervals. The formed lock plate is fixed to the valve rod, and the position shift detector is provided between the drive shaft and the valve rod, between the valve box and the stand, and between the stand and the valve drive device, or a part thereof. Is provided, and the pin output is based on the detection signal of the position shift detector. By protruding said anchor pin to drive the drive unit, it is characterized by being configured so as to fit into any of the locking holes of the anchor pin.

According to the above construction, a connecting tool such as a key for connecting the drive shaft and the valve rod, a connecting tool for connecting the valve box and the stand, and a connecting tool for connecting the stand and the valve drive device. If all or part of it corrodes and breaks, the valve becomes free-rotating, and when the valve rod is displaced in the circumferential direction with respect to the drive shaft due to the water pressure applied to the valve, it is detected. The pin withdrawal drive device is driven based on the detection signal of the position shift detector, whereby the protruding anchor pin is fitted into one of the lock holes of the lock plate fixed to the valve rod, and the valve body rotates freely. Can be prevented.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show a butterfly valve according to an embodiment of the present invention, in which a fluid pressure cylinder such as an air cylinder or a hydraulic cylinder (pin push-out drive device) is provided on an upper flange portion 1c of a valve box 1. 14 is provided, and an anchor pin 15 is provided in a projecting manner on a piston rod 14a protruding and retracting in parallel to the axial direction of the valve rod 2a of the fluid pressure cylinder 14, and facing the anchor pin 15 at a predetermined circumferential interval. A lock plate 17 penetrating a plurality of lock holes 16 is externally fitted and fixed to the valve rod 2a, and an electromagnetic switching valve 19 is interposed in the middle of a flow path connecting the fluid pressure cylinder 14 and the pump 18. A valve rod side limit switch (positional deviation detector) 20 is provided on the boss portion 8 of the valve rod 7a, and the valve rod 2 faces the detection lever 20a of the limit switch 20.
A protruding piece 21 is fixed to a, a valve box side limit switch (positional deviation detector) 22 is arranged at the lower end of the stand 6, and an upper flange of the valve box 1 faces a detection lever 22a of the limit switch 22. A protrusion 24 is fixed to the portion 1c, and a control device 24 for projecting the piston rod 14a of the fluid pressure cylinder 14 by switching the electromagnetic switching valve 19 based on a detection signal from each of the limit switches 20 and 22 is provided. There is.

In the above structure, the drive shaft 7a and the valve rod 2a
As the key 9 connecting the and is corroded and broken,
When the valve body 2 is in a freely rotatable state and the valve rod 2a is displaced in the circumferential direction with respect to the drive shaft 7a by the water pressure applied to the valve body 2, the detection lever 20a of the limit switch 20 is moved.
Is disengaged from the protruding piece 21, a detection signal is input from the limit switch 20 to the control device 24, the electromagnetic switching valve 19 is switched by the control device 24 based on the input signal, and the piston rod 14a of the fluid pressure cylinder 14 is moved. As shown by the phantom line in FIG. 1, the anchor pin 15 is fitted into one of the lock holes 16 of the lock plate 17 to prevent the valve body 2 from freely rotating through the valve rod 2a, and to prevent the water hammer. Can be prevented in advance.

Further, the fastening bolt 5a connecting the valve box 1 and the stand 6 is corroded and broken, so that the valve body 2
When the stand 6 is displaced in the circumferential direction with respect to the valve box 1 via the valve rod 2a and the valve drive device 7 due to the water pressure applied to the valve body 2, the detection lever 22a of the limit switch 22 moves. When the detection signal is input from the limit switch 22 to the control device 24, the anchor pin 15 is fitted into one of the lock holes 16 of the lock plate 17, and the valve body 2 is disengaged from the protruding piece 23.
Can be prevented from rotating freely, and a water hammer can be prevented in advance.

In the above configuration, the limit switches 20 and 2 are
2 is provided on the boss 8 and the stand 6, and the projection piece 2
1, 23 are provided on the valve rod 2a and the upper flange portion 1c of the valve box 1, but conversely, the limit switches 20 and 22 are provided on the valve rod 2a and the upper flange portion 1c of the valve box 1 and the protrusions are provided. The pieces 21 and 23 may be provided on the boss portion 8 and the stand 6. Further, instead of the limit switches 20 and 22, various relative speed detecting means may be used.

Further, instead of the fluid pressure cylinder 14, various driving devices such as solenoids may be used. Furthermore, in place of the pump 18, various pressure supply means such as a compressor or a gas cylinder may be used.

Although not shown, a positional deviation detector similar to the limit switches 20 and 22 and the protruding pieces 21 and 23 may be provided between the stand 6 and the valve drive device 7. As a result, the fastening bolts 5b (see FIG. 3) that connect the stand 6 and the valve drive device 7 are corroded and broken, so that the valve body 2 is in a freely rotatable state, and the water pressure applied to the valve body 2 causes the valve body 2 to rotate freely. When the valve drive device 7 is displaced in the circumferential direction with respect to the stand 6, a detection signal is input from the displacement detector to the control device 24, and the anchor pin 15 is moved to one of the lock plates 17 as in the case described above. It is possible to prevent the valve body 2 from freely rotating by being fitted into the lock hole 16 of the.

[0014]

According to the present invention, all of the connectors such as keys for connecting the drive shaft and the valve rod, the connectors for connecting the valve box and the stand, and the connectors for connecting the stand and the valve drive device. Or, if a part of it corrodes and breaks, the valve body becomes free-rotating, and the water pressure applied to the valve body causes the valve rod to be displaced in the circumferential direction with respect to the drive shaft.
The pin advance / retreat drive device is driven based on the detection signal of the position shift detector that detects it, whereby the protruding anchor pin is fitted into one of the lock holes of the lock plate fixed to the valve rod, and the valve body To prevent free rotation of
It is possible to prevent a water hammer from occurring.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a main part of a butterfly valve that is an embodiment of the present invention.

FIG. 2 is a view as viewed in the direction of arrows AA in FIG. 1;

FIG. 3 is a vertical sectional view showing an example of a butterfly valve.

[Explanation of symbols]

 1 Valve Box 2 Valve Body 2a Valve Rod 5a, 5b, 5c, 5d Fastening Bolt 6 Stand 7 Valve Drive 7a Drive Shaft 9 Key 14 Fluid Pressure Cylinder (Pin Advance / Retract Drive) 15 Anchor Pin 16 Lock Hole 17 Lock Plate 18 Pump 19 Electromagnetic switching valve 20 Limit switch (positional deviation detector) 21 Projection piece 22 Limit switch (positional deviation detector) 23 Projection piece 24 Control device

Claims (1)

[Claims] 1. A valve body is openably and closably arranged in a valve box, and a drive shaft of a valve drive device on a stand fixed on the valve box and a valve rod of the valve body are concentrically connected to each other. In a butterfly valve in which the valve body is opened and closed through the drive shaft and the valve stem by driving the valve drive device, an anchor pin is provided at an appropriate position near the valve stem of the valve box. A pin withdrawal / withdrawal drive device for withdrawing / removing in parallel with the direction is provided, and a lock plate facing the anchor pin and having a plurality of lock holes at predetermined intervals in the circumferential direction is fixed to the valve rod, and the drive shaft is provided. Between the valve stem and the valve stem, between the valve box and the stand, and between the stand and the valve drive device, or a part thereof, and a positional deviation detector is provided. Drive the pin push-out drive device to project the anchor pin. A butterfly valve characterized in that the anchor pin is fitted into any one of the lock holes by the above.