JPH1122833A - Butterfly valve - Google Patents

Abstract

(57) [Summary] [PROBLEMS] Even if backlash is generated in a fastening portion only by performing a simple structural improvement, the position is reliably maintained when the valve body is rotated to the fully open position, and the valve body swings. The inconvenience can be prevented from occurring. SOLUTION: A valve stem held in a valve box 1 in a state perpendicular to an axis a of a flow path 1A of the valve box 1 and rotatable around an axis b passing through the center of the stream line. A butterfly formed by fixing a circular valve element 5 for opening and closing the flow path 1A by rotation in the flow path 1A to 2A and 2B, and connecting an actuator 4 to one end 2A of a valve rod via a key 3 In the valve, when the valve element 5 is rotated to the fully open position, the valve rods 2A and 2B and the valve box 1 come into contact with each other, and
A stopper 14 and a contact portion 16 are provided to prevent the rotation of.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a butterfly valve and, more particularly, to an opening / closing operation mechanism such as an actuator or an operating handle for opening and closing a circular valve element provided in a flow path in a valve box having a cylindrical flow path. The present invention relates to a butterfly valve which is connected to an operating mechanism and is configured to be opened and closed via a valve stem which is rotated around an axis perpendicular to the axis of the flow path.

[0002]

2. Description of the Related Art In a conventional butterfly valve of this kind, an opening / closing operation mechanism is connected to one end of the valve stem through a fastening portion such as a rotary transmission element such as a key or a gear. When rotated to the fully open position, the pressure of the fluid flowing in the flow path divided left and right by the valve body acts on both the front and back surfaces of the valve body in a balanced manner, and the opening / closing operation mechanism itself has a position holding function. From the perspective of having
No special configuration for holding the valve in the fully open position has been employed.

[0003]

In the conventional general butterfly valve having the above-mentioned structure, the loosening of the key or the backlash of the rotary transmission mechanism is caused in the fastening portion between the opening / closing operation mechanism and the valve stem. When rattling occurs, especially when the fluid flowing in the flow path pulsates and the pressure balance acting on the front and back surfaces of the valve body is lost, the valve body swings, and as a result, the valve body is fully opened. Fluctuations in the fluid flow and pressure to the downstream side of the valve cause fluctuations in the valve body, and the valve body swings violently in the opening and closing direction due to the influence of the fluid. There was a problem that it also led to a decrease in aqueous solution.

[0004] The present invention has been made in view of the above circumstances, and even if a simple structure is improved, even if the fastening portion is loose, the position can be reliably maintained when the valve body is rotated to the fully open position. It is another object of the present invention to provide a butterfly valve which can prevent the occurrence of inconvenience due to the swing of the valve body.

[0005]

In order to achieve the above object, a butterfly valve according to the present invention comprises: a valve box having a cylindrical flow path; And, a valve stem held in the valve box in a rotatable state around an axis passing through the center of the streamline, and the inside of the flow passage is rotated by rotation of the valve stem to form the flow passage. In a butterfly valve having a circular valve body that opens and closes and an opening and closing operation mechanism connected to one end of the valve stem through a fastening portion, the valve stem and the valve box have the valve body in a fully open position. A stopper and a contact portion are provided for contacting each other when rotated to prevent rotation of the valve body. The stopper and the contact portion are rotated by rotating the valve body to the fully open position. To prevent further rotation of the valve body by contact with the Therefore, even if there is play in the fastening portion between the opening / closing operation mechanism and the valve stem, the valve body is always surely kept at the predetermined fully open position without being affected by the play. The valve body can be prevented from swinging irrespective of the pulsation of the fluid.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical sectional side view of a butterfly valve according to the present invention. The butterfly valve radially opposes a substantially central portion in the axial direction of the flow path 1A in a valve box 1 having a cylindrical flow path 1A. At the upper and lower positions, the valve stems 2A and 2B divided into upper and lower portions are respectively provided with the axis a of the flow path 1A.
Axis b that is perpendicular to the axis and passes through the center of the flow path 1A
A rotatable actuator 4 serving as an example of a rotary opening / closing operation mechanism is connected to the upper end of the upper valve stem 2A by using the key 3 as a fastening portion.

[0007] A circular valve element 5 arranged in the flow path 1A
As shown in FIG. 2, two upper and lower radially opposed portions are fixedly connected to the valve stems 2A and 2B via tapered bolts 6 and 6 and tightening nuts 7 and 7, respectively. With the rotation of 2B, the valve element 5 rotates in the flow path 1A to open and close the flow path 1A. This valve element 5
A valve body side seat surface portion 5A is formed on the outer peripheral side of the valve body, and a valve box side seat surface portion 8 is formed on the inner peripheral surface of the flow path 1A of the valve box 1 corresponding to the valve body side seat surface portion 5A. .

A cylindrical body 10 is fixed to the lower end of the lower valve stem 2B via a key 9, and the cylindrical body 10 is downwardly directed from the valve box 1 so as to rotatably fit and hold the cylindrical body 10. 1
A lid 12 for receiving and supporting a lower end surface of the lower valve stem 2B is detachably fixed to a lower end opening of the cylindrical portion 11 via a bolt 13.

The outer peripheral surface of the cylindrical body 10 fixed to the lower end of the lower valve stem 2B is provided with stoppers 14, 14 at the diametrically opposed positions facing radially outward as shown in FIG.
Are formed integrally, while the cylindrical portion 11 on the valve box 1 side is formed.
The stoppers 14, 14 are fitted on the inner peripheral surface of the valve body 5, and the circumferential grooves 15, 15 that allow rotation of the valve body 5 in a 90 ° range over the fully closed position and the fully open position, and the valve body 5. When the is rotated to the fully closed position and the fully open position, the stopper 1
4, 14 circumferential surfaces 14a, 14a, 14b, 14b
Butts 16, 16 having surfaces 16 a, 16 a, 16 b, 16 b that come into contact with each other and are integrally protruded radially inward so as to prevent rotation of the valve element 5 are formed.

In the butterfly valve configured as described above, the valve body 5 is fully urged through the actuator 4 and the valve rods 2A and 2B such that the outer peripheral surface 5A faces the valve box side surface 8. Rotate to closed position and flow path 1
In the state where A is closed, the cylindrical body 1 fixed to the lower valve stem 2B side.
One end surfaces 14a, 14a of stoppers 14, 14 integrally formed on the outer periphery of the cylindrical portion 11 are integrally formed on the inner peripheral surface of the cylindrical portion 11 on the valve box 1 side. The fully closed position of the valve body 5 is held by abutting on the end faces 16a, 16a.

When the valve body 5 is rotated by 90 ° to the fully open position via the actuator 4 and the valve rods 2A and 2B, as shown in FIG.
The other end surfaces 14b, 14b in the circumferential direction of the
6 is prevented from rotating further by contacting the other end surfaces 16b, 16b in the circumferential direction of the key 6, so that a torque can be applied to the fastening portion by the key 3 via the actuator 4. Therefore, even if looseness occurs due to looseness of the key 3 or the like at the fastening portion between the actuator 4 and the upper valve stem 2A, the valve element 5 is always kept at a predetermined fully open position without being affected by the play. To prevent the valve element 5 from oscillating irrespective of the pulsation of the fluid.

In the above-described embodiment, a description has been given of the case where the rotary drive actuator 4 is used as the opening / closing operation mechanism. However, the same effect can be obtained by using a manual rotation operation handle. .

[0013]

As described above, according to the present invention, only a simple structural improvement is provided between the valve stem and the valve box, such as providing a stopper and a contact portion which come into contact with each other at the fully opened position of the valve element. Therefore, even if play occurs in the fastening portion connecting the opening / closing operation mechanism and the valve stem, when the valve body is rotated to the fully open position, the fully open position can be reliably held, so that the fluid in the fully open state can be maintained. Regardless of the pulsation of the valve, the fluctuation of the valve body and the fluctuation of the fluid flow rate and pressure to the downstream side caused by the fluctuation and the occurrence of inconveniences such as a decrease in the water stoppage at the fully closed position are caused for a long time. This has the effect that the prevention can be surely achieved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a main part of a butterfly valve according to the present invention.

FIG. 2 is an enlarged cross-sectional view taken along line AA of FIG.

FIG. 3 is an enlarged cross-sectional view taken along the line BB of FIG. 1, showing a fully closed state of the valve element.

FIG. 4 is an enlarged cross-sectional view taken along the line BB of FIG. 1 and showing a fully opened state of the valve element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve box 1A Flow path 2A, 2B Valve stem 3 Key (an example of a fastening part) 4 Actuator (an example of an opening / closing operation mechanism) 5 Valve element 14 Stopper 16 Contact part a Flow path axis b Rotation axis

Claims (1)

[Claims] 1. A valve box having a cylindrical flow path, wherein the valve box is rotatable about an axis perpendicular to the axis of the flow path of the valve box and passing through the center of the stream line. A valve stem held by the valve box, a circular valve body that opens and closes the flow passage by rotating in the flow passage with rotation of the valve stem, and a fastening portion at one end of the valve stem. A butterfly valve having a connected opening / closing operation mechanism, wherein the valve stem and the valve box are in contact with each other when the valve body is rotated to the fully open position to prevent rotation of the valve body. A butterfly valve having a contact portion.