JPH0320623Y2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Purpose of the Invention (Field of Industrial Application) This invention relates to a locking device for a rotary valve, particularly a butterfly valve drive device.

(Prior art and issues to be solved) In rotary valves such as butterfly valves, in which the valve body rotates to open and close, the valve is driven to open and close by a fluid cylinder device connected to the valve shaft of the valve. The device has been widely used in practice.

This type of valve, especially a butterfly valve that uses a plate-shaped valve body, vibrates due to irregular forces caused by fluid turbulence when it is fully open and fully closed, causing noise and reducing the durability of the valve. may have an adverse effect on

In order to avoid such problems, it has been proposed in the past to provide a locking means to a drive device using a fluid cylinder.

FIG. 2 shows an example of such a locking mechanism.
FIG. 3 is a plan cross-sectional view of a drive device portion.

The end of the valve shaft 11 that extends in the direction perpendicular to the plane of the paper from the valve device (not shown) to the outside of the valve is inside the casing 10 of the drive device, and a Scotch yoke 12 is attached to the end of the valve shaft 11 within the casing. There is.

A cylinder 16 is attached to the casing 10, and a piston is disposed inside the cylinder 16, which is displaced laterally in the drawing by fluid pressure, and a piston rod 13 attached to the piston extends into the casing 10.

The piston rod 13 is provided with a pin 13a, and this pin 13a is connected to the Scotch yoke 12.
It is slidably engaged with a slit 12a formed in the slit 12a.

Therefore, when the piston (not shown) in the cylinder 16 moves left and right as shown in the drawing, the valve shaft 11 rotates via the piston rod 13 and Scotch yoke 12, and the valve body in the valve device (not shown) rotates.

In such a device, the piston rod 13
If is in the extreme left position (as shown), then
Annular recess 13b formed in piston rod 13
is located in a bush 15 disposed in the casing 10, and a ball 15d disposed in the bush 15 and biased toward the piston rod 13 by a spring 15b is inserted into the annular recess 1.
3b to form a lock mechanism that prevents movement of the piston rod 13, and the Scotch yoke 1
2. Irregular movement of the valve body (not shown) via the valve stem 11 can be suppressed.

Even when the Scotch yoke 12 reaches the extreme position in the opposite direction of rotation from the illustrated position, the annular recess 13a of the piston rod has the same structure as described above.
, spring 14b in bush 14, ball 1
Similarly, the valve stem 11 is
movement can be prevented.

However, in such a configuration, a seat ring made of an elastic material such as rubber is arranged on the inner surface of the annular valve body, and a plate-shaped valve body is arranged inside the seat ring and attached to the valve body. It is difficult for a butterfly valve, which opens and closes the valve by rotating the valve stem, to function satisfactorily.

To explain this, in a butterfly valve, theoretically, the valve body can be moved from the fully open position to the fully closed position.
Normally, it rotates 90 degrees, but in reality, it depends on the fluid pressure, but it is sufficient as long as the area around the valve body is in pressure contact with the inner circumference of the seat ring, so it can rotate 90 degrees from the fully open position. The reality is that it is sufficient to rotate the valve element at the following angle, and as the seat ring wears, the valve can be used in a good seat condition for a long period of time by increasing the rotation angle.

The present invention has been developed in view of the current situation, and it is possible to change the locking position of the piston rod on the drive device side in accordance with the condition of the seat ring in the butterfly valve drive device as described above. It is an object of the present invention to provide a locking device that facilitates maintenance of the valve and provides stable and good seating action at all times.

(2) Structure of the invention (technical means for solving the problem and its operation) In order to achieve the above object, the invention provides a locking device for a butterfly valve drive device that includes a casing that surrounds the end of the valve shaft of the butterfly valve; , a fluid cylinder attached to the casing, and a pin disposed in a piston rod attached to a piston in the fluid cylinder is inserted into a slit provided in a Scotch yoke attached to the end of the valve shaft in the casing. an extension of the piston rod on the opposite side of the piston is supported by a bolt that is threadably engaged with the cylinder end and is displaceable in the axial direction of the piston rod; The device is characterized by being provided with a locking mechanism that can be fixed to the device.

With this configuration, the seat ring serving as the sealing member can be used stably for a long period of time while maintaining a good sealing mechanism.

(Description of Embodiments) FIG. 1 is a plan sectional view of the main parts showing the configuration of the valve drive device according to the present invention, and its basic configuration is as follows:
There is no particular difference from that shown in FIG. 2 above.

Inside the casing 1 is an end portion of a valve shaft 2, to which a Scotch yoke 3 is attached, and a pin 4a provided on a piston rod 4 is engaged in a slit 3a of the yoke 3.

A cylinder 5 is attached to the left side of the casing 1 in the drawing, and the piston rod 4 is attached to a piston 8 disposed within the cylinder 5.

A locking mechanism having the same structure as the left end of the piston rod 13 shown in FIG. 2 is formed at the left end of the piston rod 4 (not shown).

The illustrated right end wall of the cylinder 5 is the cylinder 5.
A locking plug 6 is screwed into the outer end of the piston rod, and a spring 7b is inserted into the hole formed in the plug 6, thereby pressing the piston rod in the 4 direction. A ball 7a is provided.

An annular recess 4b is provided at the end of the piston load 4.
As shown in the figure, when the Scotch yoke 3 is at the extreme position on the valve closing side, the ball 7a engages with this annular recess 4b to fix the piston rod 4 and close the valve via the Scotch yoke 3. axis 2
suppress the movement of

When the Scotch yoke 3 rotates from the valve open position, which is approximately 90 degrees clockwise from the illustrated position, to the illustrated closed position, the valve body may be removed while the seat ring of the butterfly valve is new or when the fluid pressure is low. completely
If the valve can be closed without turning 90 degrees, screw in the bolt 6 a suitable amount to the left in the figure in advance, so that the annular recess 4b and the ball can be closed at a position where the Scotch yoke 3 is not completely rotated. 7a acts, and within the valve, the valve body and the seal ring can be sealed in a minimum pressure state in which the seal is effective.

Therefore, if the seal ring wears out with use and the valve body needs to be rotated more for sealing, the bolt 6 can be unscrewed as appropriate to change the locking position.

In the figure, reference numeral 9 is an adjustment bolt for adjusting the position of the piston rod, and reference numeral P is a port for allowing fluid to enter and exit the cylinder 5.

(3) Effects of the invention As explained above, when the invention is applied to a butterfly valve equipped with a seat ring made of an elastic member such as rubber, when the seat ring and the area around the valve body come into contact, Good sealing can be performed stably over a long period of time in response to changes in the sealable position.

[Brief explanation of drawings]

FIG. 1 is a sectional view of essential parts showing an embodiment of a valve driving device according to the present invention, and FIG. 2 is a partially cutaway plan view showing the configuration of a known valve driving device. 1...Casing, 2...Valve shaft, 3...Scotch yoke, 4...Piston rod, 6...Lock bolt.

Claims (1)

[Claims for Utility Model Registration] A butterfly valve includes a casing surrounding the end of a valve shaft, and a fluid cylinder attached to the casing, and a slit provided in a Scotch yoke attached to the end of the valve stem includes the A pin disposed on a piston rod attached to a piston in a fluid cylinder is slidably engaged in the casing, and an extension of the piston rod on a side opposite to the piston is screwed into the end of the cylinder. A locking device for a butterfly valve drive device, comprising a locking mechanism supported by a bolt movable in the axial direction of a piston rod and capable of fixing the piston rod to the bolt.