JP2002286159A - Flow regulating valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve set accuracy of regulating valve opening during low flow or fine flow regulation, shorten control time and avoid getting maintenance technique sophisticated. SOLUTION: This flow regulating valve is provided with a valve rod 4 having a valve element 5 for opening and closing a valve opening 3 attached on an end part and regulating a valve opening by moving in the axial direction, a drive mechanism driving the valve rod 4 in the axial direction. The drive mechanism is provided with a servo motor 14 having a rotational axis arranged in parallel with the valve rod 4 and driven according to an electrical signal of a designated opening setting, a screw shaft 12 connected to a rotation shaft 15 of the motor 14 and rotating with the rotation shaft 15 as one body, and a positioner including a nut part 8 threadedly engaged with the screw shaft 12 and connected to the valve rod 4. Rotation action of the screw shaft 12 is converted to linear action of the positioner 7 using a screw action to move the valve rod 4 in the axial direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow control valve for controlling a flow rate of a fluid, and more particularly to a flow control valve suitable for controlling the amount of water in a water cooling zone of a wire rolling mill.

[0002]

2. Description of the Related Art As a conventional flow control valve, for example, FIG.
The following are known. In FIG. 2, reference numeral a denotes a valve rod having a valve body c for opening and closing a valve port b attached to a lower end, and the valve rod a raises the air pressure supplied above the upper positioner d and the positioner d upward. It is moved up and down due to the collapse of the force relationship with the energizing coil spring e,
The valve opening is adjusted by this vertical movement.

[0003] The air pressure supplied above the positioner d is adjusted as follows. That is, the tension coil spring i is interposed between the arm g extending horizontally from the guide f at the center of the valve rod a and the turning piece h disposed above the arm g. The rotating piece h is horizontally attracted and pulled upward by the electromagnet j against the urging force of the tension coil spring i.

On the other hand, a diaphragm type valve device m is disposed upstream of a supply path k for supplying air pressure above the positioner d, and this valve device m controls the air pressure according to the opening degree of the valve element n. A supply path o for supplying above the positioner d, a supply path s for supplying air pressure above the diaphragm p and breaking the force relationship between the air pressure and the coil spring q to move the valve body n up and down; s and a supply path t for leaking air pressure to the rotating piece h side, and the amount of leakage from the supply path t is adjusted by the rotating operation of the rotating piece h. ing.

Here, the strength of the tension coil spring i is mechanically determined by the position of the valve element c of the valve rod a.
Is changed, the rotating piece h rotates upward or downward, the gap u between the rotating piece h and the supply path t changes, and the supply path s
The pressure of the air supplied above the diaphragm p changes. For example, when the gap u increases, the amount of leakage from the supply path t increases, and the air pressure supplied from the supply path s above the diaphragm p decreases. For this reason, the position of the valve body n whose position is determined by the force relationship between the air pressure above the diaphragm p and the coil spring q changes, and the air pressure supplied above the positioner d through the supply paths o and k is reduced. As a result, the force relationship between the air pressure above the positioner d and the coil spring e collapses, so that the positioner d and, consequently, the valve rod a move up and down, the valve element c moves up and down, and the valve opening changes. Has become.

[0006]

In the above-mentioned conventional flow regulating valve, the electromagnetic force of the electromagnet j, the spring force of the tension coil spring i, and the air pressure and the spring force of the coil spring are used.
Regarding the relationship between the air pressure and the spring force of the coil spring, two-stage amplification control of the air pressure, the spring force of the coil spring q, and the air pressure and the spring force of the coil spring e is performed to increase the setting accuracy of the valve opening. I have. For this reason, the structure becomes complicated, the response at the time of control is poor, and it takes a long time to converge on the set value.

Further, a valve rod a
When the flow rate is low or when the flow rate is finely adjusted, a slight change in the air pressure causes the valve to open due to the mechanical resistance of the seal member v and guide f when the valve body c moves up and down. Since the accuracy of the degree is lowered or the valve rod a does not move, there is a disadvantage that a high level of maintenance technology is required.

The present invention has been made in order to solve such inconvenience, and it is possible to improve the setting accuracy of the valve opening at the time of a low flow rate and at the time of fine adjustment of the flow rate with a simple structure, and to improve the control time. It is an object of the present invention to provide a flow control valve capable of reducing the time required for the maintenance and avoiding the advancement of the maintenance technology.

[0009]

In order to achieve the above object, a flow control valve according to the present invention is provided with a valve body for opening and closing a valve port at an end portion, and the valve body is moved in an axial direction to open the valve. And a drive mechanism for moving the valve rod in the axial direction, wherein the drive mechanism has a rotation axis parallel to the valve rod and a predetermined opening degree. A servomotor that is driven to rotate in accordance with the set electric signal; a screw shaft that is connected to the rotation shaft of the servomotor and rotates integrally with the rotation shaft; and a nut portion that is screwed to the screw shaft. And a positioner connected to the valve rod, and converting the rotational movement of the screw shaft into a linear movement of the positioner using a screw action to move the valve rod in the axial direction. Characterized by

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory cross-sectional view illustrating a flow control valve according to an embodiment of the present invention. In this embodiment, a flow control valve used for controlling the amount of water in a water-cooled zone of a wire rod rolling line is taken as an example.

In FIG. 1, reference numeral 1 denotes an inflow passage for fluid formed in the valve body B, 2 denotes an outflow passage, and a valve port 3 is formed between the inflow passage 1 and the outflow passage 2. A valve rod 4 is inserted through the valve port 3, and a distal end (lower end) of the valve rod 4 has a valve body 5.
Are formed. As the valve rod 4 moves in the axial direction, the valve port 3 is opened and closed by the valve body 5, and
The opening is adjusted in accordance with the amount of movement of the valve rod 4 in the axial direction.

The base end (upper end) of the valve rod 4 is connected to a positioner 7 via a seal member 6. The positioner 7 includes a nut portion 8 having an axis parallel to the axis of the valve rod 4, and is supported by a linear guide mechanism 9 so as to be movable in the axial direction of the valve rod 4. In addition,
The linear guide mechanism 9 includes a slide portion 10 provided on the positioner 7 and a guide rail 11 attached to the housing H.

A screw shaft 12 having an axis parallel to the axis of the valve rod 4 is rotatably supported on the housing H via a plurality of bearings 13. The screw shaft 12 has a nut portion of the positioner 7. 8 is screwed. Further, a servomotor 14 is disposed at an end (upper end) of the screw shaft 12 on the side away from the valve body 5. The servomotor 14 is mounted on the housing H via a bracket 16 with its rotation axis aligned with the screw shaft 12 and the rotation shaft 15 facing the screw shaft 12 side.
Is connected to the screw shaft 12 via a joint 17.

Then, an electric signal corresponding to the valve opening setting is output from a control device (not shown) to the drive circuit of the servo motor 14 so that the servo motor 14 rotates forward or reverse at a rotation angle corresponding to the valve opening setting. Screw shaft 1 driven to rotate in the direction
2 rotates integrally with the rotating shaft 15 and the rotational movement of the screw shaft 12 is converted into a linear movement of the positioner 7 by a screw action, whereby the valve rod 4 moves up and down in the axial direction to adjust the valve opening. Is done.

As described above, in this embodiment, the rotation of the servomotor 14 is transmitted to the screw shaft 12, and the rotational movement of the screw shaft 12 is converted into the linear movement of the positioner 7 by utilizing the screw action, thereby providing the valve. Since the valve opening is adjusted by directly mechanically moving the rod 4 up and down, a simple structure can be achieved, and the servomotor 14 having high rotation accuracy even at low flow rate and fine flow rate adjustment. The drive accuracy and the mechanical mechanism can improve the setting accuracy of the valve opening, and the response speed during control can be greatly improved compared to the past, so the control time is shortened. And maintenance of the maintenance technology can be prevented from becoming more sophisticated.

[0016]

As is apparent from the above description, according to the present invention, it is possible to improve the setting accuracy of the valve opening at the time of low flow rate and at the time of fine adjustment of the flow rate with a simple structure and to reduce the control time. The effect of shortening the time and avoiding the advancement of maintenance technology can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view for explaining a flow control valve which is an example of an embodiment of the present invention.

FIG. 2 is an explanatory sectional view for explaining a conventional flow control valve.

[Explanation of symbols]

 3 ... Valve 4 ... Valve rod 5 ... Valve 7 ... Positioner 8 ... Nut 12 ... Screw shaft 14 ... Servo motor

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H052 AA01 BA03 BA25 CD01 CD09 DA01 EA02 EA16 3H062 AA02 BB10 BB30 BB31 CC01 DD01 EE06 FF41 HH03 HH10 3H063 AA01 BB02 BB24 BB32 BB47 DB04 DB50 EE01 GG01

Claims (1)

[Claims] 1. A valve body that opens and closes a valve port is attached to an end, and includes a valve rod that adjusts a valve opening degree by moving in an axial direction, and a drive mechanism that moves the valve rod in an axial direction. A flow adjustment valve, wherein the drive mechanism has a rotation axis parallel to the valve rod, and a servomotor that is driven to rotate in accordance with an electric signal for setting a predetermined opening degree; and a rotation axis of the servomotor. A screw shaft connected to the rotary shaft and integrally rotating with the rotary shaft; and a positioner having a nut portion screwed to the screw shaft and connected to the valve rod. A flow regulating valve characterized in that the valve rod is moved in the axial direction by converting the movement into a linear movement of the positioner using an action.