JP2002061761A - Counterweight mechanism for check valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a counterweight mechanism for a check valve that can easily open a valve element against a controlled fluid in a positive direction and easily close the valve element while a small flow rate of fluid flows in the opposite direction. SOLUTION: A valve element 12 is disposed in a valve casing 11 so as to pivot on the axis of a horizontal valve stem 13 and to swing between a full closing position and a full opening position. An arm 14 swingable on the axis of the valve stem 13 integrally therewith is inclined to the vertical at a given angle in the closing direction of the valve element 12 when the valve element 12 is in the full closing state. The arm 14 is mounted on one end with a counterweight 15 swingable on the axis thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a check weight mechanism for a check valve, and more particularly to a check valve technology installed on a discharge side of a pump or a blower in a sewage treatment plant, a water purification plant, or the like.

[0002]

2. Description of the Related Art FIG. 4 shows a non-return valve of this type. In FIG. 4, a valve body 3 for opening and closing a port 2 is provided inside a valve box 1 so as to be rotatable about the axis of a horizontal support shaft 4. The valve seat 6 is disposed in contact with the valve body 3 in a watertight manner. A weight lever 7 is provided on one end side of the support shaft 4, and a counter weight 8 is provided on the weight lever 7.

According to this configuration, a moment in the closing direction due to the weight of the valve body 3 and a moment in the opening direction due to the counterweight 8 act on the valve body 3 around the axis of the support shaft 4. Since the moment in the closing direction is greater than the moment in the opening direction, the valve body 3 maintains the plugged state in a state where the water flow does not flow through the pipeline. To open.

[0004]

However, in the above-mentioned conventional construction, in order for the valve body 3 to be opened by a small flow of water, the opening direction moment by the counterweight 8 may be set to be large. The larger the moment, the slower the closing movement becomes and the more difficult it is to close, and when the water flow in the opposite direction flows at a small flow rate, the closing operation timing is shifted and the check function is disturbed, and the water stop pressure is reduced. There was a problem of leaking water.

[0005] The present invention is to solve the above problems,
Provided is a check valve counterweight mechanism in which a valve body can be easily opened for a controlled fluid in a forward direction and can be easily closed when a small amount of fluid flows in a reverse direction. The purpose is to.

[0006]

In order to solve the above-mentioned problems, a counterweight mechanism of a check valve according to the present invention is rotated around the axis of a horizontal valve rod in a valve box so as to be in a fully closed position. A valve body that swings over the fully open position is provided, and an arm that swings integrally with the valve stem around the axis of the valve stem is moved in the closing direction of the valve body with respect to the vertical direction when the valve body is fully closed. The arm is provided to be inclined at a predetermined angle, and a counter weight that swings around its axis is provided at one end of the arm.

With the above arrangement, in the fully closed state of the valve body, the arm is inclined at a predetermined angle in the closing direction of the valve body with respect to the vertical direction, and the counter weight provided on the arm is moved in the closing direction of the valve body. The posture swings to. For this reason, a closing moment due to the weight of the valve body and a closing moment due to the own weight of the arm and the counterweight act around the axis of the valve stem.

When the controlled fluid flows in the forward direction, the valve body swings from the fully closed position toward the fully open position, and the arm swings with the swing of the valve body, so that the valve body has a certain opening degree or more. When the arm is opened, the arm is inclined in the opening direction of the valve body with respect to the vertical direction, and the counter weight provided on the arm swings in the opening direction of the valve body. Due to the reversal of the counterweight, the moment due to the own weight of the arm and the counterweight is rapidly reversed and acts in the opening direction, and opposes the closing moment due to the own weight of the valve element around the axis of the valve rod. Therefore, the opening of the valve body by the forward flow can be easily performed, and the smooth operation of the valve body can be ensured even when the flow rate of the controlled fluid is small.

When the flow of the controlled fluid in the forward direction stops, the valve element is closed by the force of the difference between the opening moment of the arm and the counterweight due to its own weight and the closing moment of the valve element due to its own weight. When the arm swings with the movement and the valve body closes below a certain opening, the arm is inclined in the closing direction of the valve body with respect to the vertical direction, and the counter weight provided on the arm closes the valve body. Inverts in the moving direction and swings.
Due to the reversal of the counterweight, the moment due to the weight of the arm and the counterweight suddenly reverses and acts in the closing direction. Both act in the closing direction, the valve body closes quickly, and a certain water stopping surface pressure is generated, so that reliable water stopping can be exhibited.

Therefore, even when the flow of the controlled fluid in the forward direction stops and the controlled fluid flows in the reverse direction at a small flow rate, the valve body closes quickly near the fully closed position, thereby providing a check valve. The check function can be reliably demonstrated.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. In FIGS. 1 to 3, a valve body 12 for opening and closing a port 11 a of a flow path in the valve box is disposed inside the valve box 11. The valve element 12 is rotatably provided around the axis of the horizontal valve rod 13, and is between a fully closed position inclined at a predetermined angle with respect to the vertical direction and a fully opened position in contact with the stopper 11 b of the valve box 11. To rock.

The valve box 11 rotatably supports the valve rod 13, and has an arm 14 at one end of the valve rod 13 swinging integrally with the valve element 12. The arm 14 swings integrally with the valve rod 13 and is inclined at a predetermined angle in the closing direction of the valve body 12 with respect to the vertical direction in a state where the valve body 12 is fully closed. A counter weight 15 swinging around the axis is provided. The valve stem 13 is provided with detent portions 16, 16 for receiving the counterweight 15 at a predetermined position, and the counterweight 15 swings around the axis of the valve stem 13 between the two detent portions 16, 16. .

The operation of the above configuration will be described below. In the fully closed state of the valve body 12, the arm 14 is inclined at a predetermined angle in the closing movement direction of the valve body 12 with respect to the vertical direction, and the counter weight 15 provided on the arm 14 swings in the closing movement direction of the valve body 12. To move to the position to engage with one of the locking portions 16. Therefore, a closing moment due to the own weight of the valve body 12 and a closing moment due to the own weight of the arm 14 and the counterweight 15 act around the axis of the valve rod 13.

The valve element 12 swings from the fully closed position to the fully opened position when the controlled fluid flows in a forward flow. Valve body 12
When the arm 14 swings along with the swing of the valve body 12 and the valve body 12 is opened to a certain degree or more, the arm 14 is moved in the vertical direction.
The counter weight 15 provided on the arm 14 swings in the opening direction of the valve body 12 and engages with the other detent portion 16. Due to the reversal of the counterweight 15, the moment due to the own weight of the arm 14 and the counterweight 15 is suddenly reversed and acts in the opening direction, and is opposed to the closing moment due to the own weight of the valve body 12 around the axis of the valve rod 13. I do. Therefore, the opening movement of the valve element 12 by the forward flow can be easily performed, and the smooth operation of the valve element 12 can be ensured even when the flow rate of the controlled fluid is small.

When the forward flow of the controlled fluid stops, the valve 1
Numeral 2 is closed by a difference force between the opening moment of the arm 14 and the counterweight 15 due to its own weight and the closing moment of the valve body 12 due to its own weight. When the arm 14 swings with the swing of the valve body 12 and the valve body 12 closes below a certain opening degree, the arm 14 assumes a posture inclining in the closing direction of the valve body 12 with respect to the vertical direction. The counterweight 15 provided on the valve body 14 is inverted in the closing direction of the valve body 12 and swings.

Due to the reversal of the counterweight 15, the moment due to the own weight of the arm 14 and the counterweight 15 is rapidly reversed and acts in the closing direction, and the valve stem 1
3, the moment due to the weight of the valve body 12 and the moment due to the weight of the arm 14 and the counterweight 15 both act in the closing direction, and the valve body 1 is quickly moved.
2 is closed, and a certain water stoppage pressure is generated, so that reliable water stoppage can be exhibited.

Therefore, even when the flow of the controlled fluid in the forward direction stops and the controlled fluid flows in the reverse direction at a small flow rate, the valve body 12 quickly closes near the fully closed state,
The check function as a check valve can be reliably exhibited.

[0018]

As described above, according to the present invention, the posture of the arm is inclined in the closing direction of the valve body and the posture inclining in the opening direction of the valve body at a predetermined opening degree of the valve body. When the counterweight is reversed, the counterweight reverses and swings.The reversal of the counterweight causes the moment due to the weight of the arm and the counterweight to rapidly reverse and act in the opposite direction. The valve element easily opens and closes against the flow, and when closed, the valve element closes quickly and a certain level of water stoppage pressure can be used to ensure reliable water stoppage. Even when the fluid flows through the valve, the valve body quickly closes in the vicinity of the fully closed state, so that the check function as the check valve can be reliably exhibited.

[Brief description of the drawings]

FIG. 1 is an overall sectional view of a check valve showing an embodiment of the present invention.

FIG. 2 is a front view of a counterweight of the check valve.

FIG. 3 is a plan view of a counterweight of the check valve.

FIG. 4 is an overall sectional view of a conventional check valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Valve box 11a Port 11b Stopper 12 Valve 13 Valve stem 14 Arm 15 Counter weight 16 Stop part

Claims (1)

[Claims] 1. A valve body which is pivoted around an axis of a horizontal valve stem and swings between a fully closed position and a fully opened position in a valve box, and is integrally formed with the valve stem around the axis of the valve stem. Swinging arm
When the valve body is fully closed, the valve body is provided at a predetermined angle in the closing direction of the valve body with respect to the vertical direction, and a counter weight that swings around its axis is provided at one end of the arm. Counterweight mechanism of check valve.