JPH0435652Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a drive device for rapid shutoff of a ball valve, particularly a large ball valve.

Prior Art Large on-off valves are widely used in gas combustion piping and the like. If an accident occurs in a part of the piping, such as a burner to which the piping is connected, it is necessary to quickly shut off the valve. However, in the case of a large-sized valve, large inertia acts upon the valve when it moves to shut off the flow path from the open state to the closed state, and the kinetic energy becomes extremely large when attempting to shut off the flow path in a short period of time. If the valve body, which has a large amount of kinetic energy, comes into contact with the stopper and attempts to stop it at a predetermined position, it is inevitable that a large impact will be generated, causing vibrations in the piping and possibly destroying the valve itself. For this reason, rapid shutoff using large valves was considered impossible. However, in recent years, in order to effectively shut off the gas in the event of an explosion in large-diameter piping, there has been a rapidly increasing demand for shutting off the gas within, for example, about one second.

To reduce the impact of rapidly closing the valve,
A method of buffering the fluid by constricting the fluid passage at the stroke end of the piston of the fluid cylinder of a rotary actuator can be considered based on the ordinary cylinder structure, but in a cylinder with such a structure, the flow passage is constricted even when the piston starts driving. There is a problem that the operating speed and output decrease.

Purpose The purpose of the present invention is to provide a rapid shutoff drive device as a large ball valve, which has not been available in the past.

Structure and operation In order to achieve the above object, the present invention has a large ball valve and a rotary actuator that drives the ball valve, and the piston is in direct or indirect contact with the fluid pressure cylinder of the rotary actuator. This was achieved by installing the shock absorber as an independent component.

With this invention, in a large ball valve, the ball as a valve body has a relatively long holding stroke after opening/closing the flow path, and there is no need to stop the ball etc. with a stopper at the end of the opening/closing stroke when opening/closing the valve. It is sufficient if it can be stopped within the range. Therefore, when the ball closes the flow path, the valve body is rotated at a predetermined high speed until it reaches the closing position, and then stopped while absorbing the impact within a predetermined short time after closing. For this purpose, a single shock absorber is removably installed in the fluid pressure cylinder part of the rotary actuator, such as an air cylinder part, and after the flow path of the valve is closed, the piston comes into contact with the shock absorber, and during a short stroke, the shock absorber is Stop while absorbing.

The piston can always operate the ball valve at the required speed and output without restricting the flow path like the normally used buffer mechanism of a fluid cylinder.

Embodiments The details of the structure and operation of the present invention will be explained based on embodiments shown in the drawings.

1 and 2, the ball valve driving device according to the present invention is equipped with a large ball valve 1 and a rotary actuator 2 for driving the large ball valve 1.

The large ball valve 1 itself is a widely used ball valve, and a detailed explanation of its structure will be omitted.
Inlet channel 3, outlet channel 4, and both channels 3, 4
The main body 6 has a valve chamber 5 formed therebetween, and a ball valve body 7 rotatably accommodated in the valve chamber 5. The ball valve body 7 has an inlet passage 3 and an outlet passage 4.
A through flow path 7' is formed which can communicate with the two at the same time.

A seat 8 is in contact with the ball valve body 7, and the flow path 3,
4, 7' and the valve chamber 5 are sealed.

A support shaft 9 and a stem 10, which are rotatably supported by the main body 6, extend coaxially to the ball valve body 7.
It is fixed so that it extends from both sides. stem 10
passes through the main body 6 and is sealed by a ground portion 11.

An intermediate support 12 is fixed to the main body 6 of the ball valve 1 with bolts 13, and a casing 14 of the rotary actuator 2 is fixed to the intermediate support 12 with bolts 15.

The stem 10 of the ball valve 1 and the output shaft 16 of the rotary actuator 2 are connected to each other by a coupling 17. The coupling ring 17 has a stem 1 attached to one end.
The output shaft 16 has an engagement hole 18 that engages with the square end of the output shaft 16, and is inserted into a hollow hole of the output shaft 16 and locked with a key. If the coupling ring 17 is integrally formed with the output shaft 16, the output shaft 16 of the rotary actuator 2
It is also possible to have a structure in which the valve is connected directly to the stem 10 of the ball valve 1 by insertion. Output shaft 16 and stem 10
The connection mode of is not limited to this example,
Any structure can be used as long as the rotational motion of the output shaft 16 is reliably transmitted to the stem 10.

As shown in FIGS. 3 and 4, the rotary actuator 2 converts linear motion of an output shaft 16 rotatably supported by a casing 14, a fluid pressure cylinder 19, and a piston rod 20 of the fluid pressure cylinder 19 into rotational motion and outputs the output shaft. Linear/rotational conversion device 2 transmitting to shaft 16
1.

The linear/rotational conversion device 21 is a piston rod 2
A pin 22 attached to or integrally formed with the pin 22 and a ring 23 fitted to the pin 22
The arm 2 has a long groove 24 into which the arm is inserted and guided.
5, and the arm 25 is fixedly fitted or integrally formed with the output shaft 16. The arm 25 is reciprocated and pivoted about the axis of the output shaft 16 by the movement of the pin 22 as the piston rod 20 reciprocates.
An adjustment screw 26 that acts as a stopper for limiting the range of rotation of the arm 25 is screwed into the casing 14, and the rotation angle of the arm 25 is finely adjusted by adjusting the screwing amount of the adjustment screw 26. The adjusting screw 26 is locked in the adjusted position by a locking nut 27.

A lock cover 28 of the hydraulic cylinder 19 is fixed to the casing 14. Fluid pressure cylinder 19
has a rod cover 28, a head cover 29, a cylinder tube 30 mounted between both covers 28, 29, a piston 31 slidingly guided by the cylinder tube 30, and a piston rod 20 fixed to the piston 31. piston rod 2
0 extends into the casing 14 and is slidably supported by the bushing 32. Reciprocating piston rod 2
0 is prevented from being exposed to the outside by a cover 33 fixed to the casing 14.

A shock absorber 34 is attached to the head cover 29 of the fluid pressure cylinder 19. It is convenient that the shock absorber 34 is attached to the head cover 29 by screwing, for example, and the position of contact with the piston 31 or the piston rod 20 can be adjusted by adjusting the amount of screwing. The mounting position of the shock absorber 34 is not limited to the illustrated position, but may be any position as long as it is in direct or indirect contact with the piston 31 and can absorb the kinetic energy acting on the piston.

As the shock absorber 34, for example, a structure as shown in FIG. 5 can be used. Fifth
In the figure, 51 is a piston rod, 52 is a head housing, 53 is an integrated rod seal, 54 is an O-ring, 55 is a metal, 56 is a piston, and 57
is the check ball, 58 is the check spring,
59 is a screw case, 60 is a mounting nut, 61 is a return spring, 62 is an accumulator, and 63 is a fuel plug.

The piston 31 is reciprocated by fluid pressure, such as air pressure, supplied to the fluid pressure cylinder 19, and the reciprocation is caused by the arm 25 via the piston rod 20.
The rotational motion is transmitted to the stem 10 via the output shaft 16, and transmitted to the stem 10 in a reciprocating manner. The reciprocating rotation of the stem 10 causes the ball valve body 7 to reciprocate and open and close the flow path. Since there is nothing to directly prevent the ball valve body 7 from rotating when the valve is opened or closed, no impact is applied to the ball valve body 7 itself. Therefore, the valve body 7 itself does not pose any obstacle to high-speed rotation.
In order to transmit high-speed rotation to the valve body 7, it is necessary to reciprocate the piston of the fluid pressure cylinder 19 at high speed. Furthermore, the piston 31 must be stopped at a predetermined position. When the piston 31 stops, the kinetic energy is absorbed by the shock absorber 34,
To avoid impact on the piston 31 or piston rod 20.

When the ball valve body 7 blocks the flow path by rotation,
In a large ball valve, the circumferential area of the ball is relatively large compared to the diameter area of the flow path, and it is possible to maintain shutoff within a certain angular range. Therefore, the piston 31 moves at high speed without providing any resistance until the flow path is blocked, and from immediately after the blockage to the piston stop position, that is, within the angular range where the ball valve body blocks the flow path. The piston 31 comes into contact with the piston rod 51 of the shock absorber 34 in the shortest possible range, and the kinetic energy is absorbed by the hydraulic pressure inside the shock absorber 34, causing the piston 31 to decelerate, and at a predetermined position, the arm 25 comes into silent contact with the adjustment screw 26. This causes the piston 31 and the ball valve body 7 to stop.

When the ball valve body 7 opens and closes, the fluid pressure cylinder 19 can operate with maximum output at startup.

Effects With this invention, the ball valve can open and close at high speed.
The hydraulic cylinder always operates at maximum output, and when it stops, it is now possible to stop it quietly without creating a shock due to the action of the shock absorber. The present invention makes it possible to perform rapid shutoff without adverse effects of shock or vibration on piping, etc., making it possible to provide a large-sized rapid shutoff valve that was previously considered impossible.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view of the quick shutoff valve according to the present invention, Fig. 2 is a right side view, Fig. 3 is a plan cross-sectional view of the rotary actuator, Fig. 4 is a - sectional view of Fig. 3; The figure is a sectional view of an example of a single shock absorber. 1...Ball valve, 2...Rotary actuator,
10... Stem, 16... Output shaft, 19... Fluid pressure cylinder, 20... Piston rod, 21...
Linear/rotational conversion device, 31...Piston, 34...
...Shock absorber.

Claims (1)

[Scope of utility model registration request] The rotary actuator has a ball valve and an output shaft connectable to a stem provided on a ball valve body of the ball valve, and the rotary actuator converts a fluid pressure cylinder and linear motion of the fluid pressure cylinder into rotational motion. In a ball valve driving device having a linear/rotational conversion device, the piston of the fluid pressure cylinder is directly or indirectly operated only between a rotational position where the ball valve body closes the flow path and a rotational position where the ball valve body stops. A ball valve driving device, characterized in that a shock absorber is attached to the fluid pressure cylinder so as to be able to come into contact with it.