JP2003314724A - Flow control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow control valve wherein rotational driving torque of a stepping motor is reduced when the rotation of the stepping motor is displaced to an axis direction by a screw feeding mechanism and a poppet valve is operated. <P>SOLUTION: A stator 2 is arranged on an outside of a body 1 of a valve, a rotor 3 is arranged in an inside, and a rotor magnet 4 is fitted on an outer periphery of the rotor 3 to constitute the stepping motor SM. A female screw 3N of the rotor 3 and a male screw 5 of the body 1 are screwed to each other, the poppet valve 6 is displaced to the axis direction by rotations of rotor 3 by the screw feeding mechanism NM while a valve shaft 6S of the poppet valve 6 is supported by a guide 11 of the body 1 to control the flow. At this time, a ball bearing 12 intervenes between the valve shaft 6S of the poppet valve 6 and a fitting part of the rotor 3, and thereby the rotational torque is reduced during operation of the poppet valve 6, to miniaturize a whole of the flow control valve. <P>COPYRIGHT: (C)2004,JPO

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 by displacing a valve shaft by utilizing a rotational force of a motor.

[0002]

2. Description of the Related Art Conventionally, in order to perform fine flow rate control,
The rotational displacement of the stepping motor is converted into a linear displacement by the screw feed mechanism, and the poppet valve is locked to this displacement body.
A control valve that controls the flow rate by finely controlling the position of the poppet valve has been proposed.

FIG. 4 is a longitudinal sectional view showing this conventional control valve, in which the stator 2 of the stepping motor SM is arranged outside the body 1 of the poppet valve 6 and the rotor 3 is arranged inside. . A rotor magnet 4 is integrally joined to the outer circumference of the rotor 3. A female screw 3N is provided on the inner circumference of the rotor 3 and the poppet valve 6
A fixed male screw 5 is provided on the body 1 side, and both are screwed together. The screw feeding mechanism NM is configured by screwing the female screw 3N and the male screw 5 together. The rotor 3 is rotatably supported on the body 1. The valve shaft 6S of the poppet valve 6 is supported by the guide 11 of the body 1, and the upper end of the valve shaft 6S is locked to the rotor 3. A compression spring 7 is interposed so as to urge the valve shaft 6S downward. Ie poppet valve 6
A compression spring 7 is interposed so as to operate as a relief when fully closed. The tip of the poppet valve 6 has a conical shape and moves forward and backward with respect to a valve opening 1V provided in the body 1 to form a valve. Reference numeral 8 is a retaining ring for locking the valve shaft 6S and the rotor 3.

The conventional flow control valve is constructed as described above, and when a rotating magnetic field is formed in the stator 2 for controlling the flow rate in the stepping motor SM, a rotating force is generated in the rotor magnet 4, and as a result, the rotor 3 is rotated. Rotates about a fixed male screw 5 as an axis and is axially displaced by a screw feeding mechanism NM. Due to the displacement, the poppet valve 6 is opened and closed to control the flow rate. Since the opening / closing of the poppet valve 6, that is, the axial displacement can be expanded to the rotational displacement of the rotor 3 by the screw feeding mechanism NM, the displacement of the poppet valve 6 can be finely adjusted by adjusting the rotation amount.

When the rotating magnetic field is stopped, the rotation of the rotor 3 is fixed, so that the opening degree (position) of the poppet valve 6 can be maintained. Since the driving force for opening / closing the poppet valve 6 is internally generated by the indirect transmission of the rotating magnetic field, the inside and outside of the valve can be completely shielded and the control fluid does not leak. The open / closed state of the valve is shown in FIG. 5. In FIG. 5, the right side of the center line shows the closed state of the poppet valve 6, and the left side of the center line shows the opened state of the poppet valve 6.

[0006]

This type of flow control valve has the excellent characteristics as described above, but the driving force required for opening the poppet valve 6 is large, and therefore the stepping motor is required. There is a problem that it becomes large and it is difficult to downsize the entire control valve. That is, the rotational torque from the stepping motor SM is supplied as the driving force for opening and closing the poppet valve 6, and the magnitude of this rotational torque is the rotational friction torque in the screw feed mechanism NM and the compression spring 7 and the rotor 3. Is the total torque of the rotational friction torque of the poppet valve 6 and the rotational friction torque of the valve opening 1V. This is because the valve shaft 6S of the poppet valve 6 is engaged with the rotor 3 via the retaining ring 8 in a surface-bonding manner and is biased by the compression spring 7.

Due to the characteristics of the flow control valve, it is often necessary for the poppet valve 6 to be displaced from the rest state in which the poppet valve 6 is seated at the valve opening 1V. At this time, the stepping motor SM is used.
It is necessary to generate a large starting torque such as the above total torque, the stator 2 and the rotor magnet 4 must be made large, the stepping motor SM becomes large, and the flow control valve as a whole is made small. Is difficult. In addition, when the compression spring 7 and the rotor 3, the poppet valve 6 and the valve opening 1V are rotated and slipped, metal powder is generated, and when the wear powder is caught in the valve seat, the flow rate control malfunctions. There was also a problem that there is a possibility of clinging between the poppet valve 6 and the valve opening 1V.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a flow control valve capable of reducing the size of a stepping motor and improving the durability and reliability of flow control. I am trying.

[0009]

In order to achieve the above-mentioned object, a flow control valve provided by the present invention comprises a screw provided on a peripheral surface of a rotor of a motor and a fixing screw on a body side of the valve screwed together. In a flow rate control valve having a screw feed mechanism, the valve shaft is locked to the rotor that is displaced in the axial direction by the operation of the screw feed mechanism, and the flow rate is controlled by the valve displacement. It is characterized in that a rolling bearing is interposed between the locking portions of and. Since the flow control valve of the present invention is configured as described above, the rotation friction torque is generated specifically, the rotation at the spring and the rotor, the poppet valve and the valve opening is reduced, and the operation of the rolling bearing is reduced. The required starting torque of the stepping motor can be reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A flow control valve according to the present invention will be described below with reference to an embodiment shown in the drawings. FIG. 1 is a diagram showing a basic configuration of a flow control valve provided by the present invention, and shows the entire control valve in a vertical cross section.

A stepping motor SM is provided outside the body 1.
The stator 2 is installed and the rotor 3 is provided inside.
Are arranged. A rotor magnet 4 is integrally joined to the outer circumference of the rotor 3. A female screw 3N is provided on the inner circumference of the rotor 3, and a fixed male screw 5 is provided on the body 1 side of the poppet valve 6, which are screwed together. The screw feeding mechanism NM is configured by screwing the female screw 3N and the male screw 5 together. The rotor 3 is rotatably supported by a male screw 5 of the body 1 and a female screw 3N of the rotor 3. An outer ring of a ball bearing 12 is locked to the rotor 3 by a retaining ring 9. Further, the compression spring 7 is arranged on the outer circumference of the valve shaft 6S and is interposed so as to urge the inner ring of the ball bearing 12 upward and the poppet valve 6 downward. On the other hand, the upper end of the valve shaft 6S is locked to the inner ring of the ball bearing 12 by the repulsive force of the compression spring 7 and the retaining ring 8.
That is, the rotor 3 and the valve shaft 6S are locked by the ball bearing 12. The inner ring of the ball bearing 12 and the valve shaft 6S are fitted to each other so that when the poppet valve 6 is completely closed, the displacement of the rotor 3 can be further escaped by slipping through the compression spring 7. A valve shaft 6S of the poppet valve 6 is supported by a guide 11 of the body 1. The tip of the poppet valve 6 has a conical shape and the valve port 1V provided in the body 1
To move back and forth to form a valve.

In the above structure, the present invention is characterized in that the radial type ball bearing 12 capable of applying a thrust load is interposed between the portion of the poppet valve 6 that engages with the rotor 3, that is, the valve shaft 6S. That is, this ball bearing 12
As a result, the rotational torque of the rotor 3 is not transmitted to the valve shaft 6S, and the valve shaft 6S does not rotate. The rotating magnetic field generated in the stator 2 for controlling the flow rate causes the rotor magnet 4 to generate a rotating force. As a result, the rotor 3 is driven to rotate with the male screw 5 as an axis, and the screw feeding mechanism NM is used.
Is displaced in the axial direction by. Due to this displacement, the poppet valve 6 locked to the rotor 3 opens and closes the valve opening 1V, but since the rotational component of the poppet valve 6 unnecessary for opening and closing disappears, the ball bearing 12 is interposed.

The flow control valve provided by the present invention is as described above in detail, but is not limited to the above and illustrated examples, and includes various modified embodiments. 2 and 3 show a modified embodiment of the control valve as a whole in a longitudinal section. 1 shows a configuration in which the poppet valve 6 is opened by moving upward, the embodiment shown in FIG. 2 is a flow control valve having a configuration in which the poppet valve 6 is opened by moving downward. See also FIG.
In the embodiment shown in, the thrust ball bearing 10 and the thrust ball bearing 1 are shown.
This is a flow rate control valve having a structure in which the rotor 3 and the poppet valve 6S are locked with 0A interposed.

In FIG. 2, the stator 2 of the stepping motor SM is arranged outside the body 1, and the rotor 3 is arranged inside. The body 1A is obtained by dividing the body 1 in order to assemble the poppet valve 6 to the body 1, and is the same as the body 1 after the assembly. A rotor magnet 4 is integrally joined to the outer circumference of the rotor 3. A female screw 3N is provided on the inner circumference of the rotor 3, and a fixed male screw 5 is provided on the body 1 side of the poppet valve 6, which are screwed together. By screwing the female screw 3N and the male screw 5, the screw feeding mechanism NM
Is configured. The rotor 3 is rotatably supported by a male screw 5 of the body 1 and a female screw 3N of the rotor 3.
An outer ring of a ball bearing 12 is locked to the rotor 3 by a retaining ring 9. Further, the compression spring 7 is arranged on the outer periphery of the valve shaft 6S and is interposed so as to urge the inner ring of the ball bearing 12 downward and the poppet valve 6 upward. On the other hand, the valve shaft 6S is locked to the inner ring of the ball bearing 12 by the repulsive force of the compression spring 7 and the retaining ring 8. That is, the rotor 3 and the valve shaft 6S are locked by the ball bearing 12. The inner ring of the ball bearing 12 and the valve shaft 6S are fitted to each other when the poppet valve 6 is completely closed.
As a relief of the further displacement of the rotor 3, it is fitted so that it can slide through the compression spring 7. Also, the poppet valve 6
The valve shaft 6S is supported by the guide 11 of the body 1. The tip of the poppet valve 6 has a conical shape and moves up and down to form a valve.

In FIG. 3, the stator 2 of the stepping motor MS is arranged outside the body 1, and the rotor 3 is arranged inside. A rotor magnet 4 is integrally joined to the outer circumference of the rotor 3. A female screw 3N is provided on the inner circumference of the rotor 3, and a fixed male screw 5 is provided on the body 1 side of the poppet valve 6, which are screwed together. The screw feeding mechanism NM is configured by screwing the female screw 3N and the male screw 5 together. The rotor 3 is rotatably supported by a male screw 5 of the body 1 and a female screw 3N of the rotor 3. The compression spring 7 is arranged on the outer circumference of the valve shaft 6S and intervenes so as to urge the inner ring of the thrust ball bearing 10A upward, and the outer ring of the thrust ball bearing 10A and the outer ring of the thrust ball bearing 10 are the rotor 3 and the outer ring of the thrust ball bearing 10A.
Thrust ball bearing 10
The inner ring of is locked to the valve shaft 6S by a retaining ring 8. That is, the rotor 3 and the valve shaft 6S are locked by the thrust ball bearing 10 and the thrust ball bearing 10A. The thrust ball bearing 10 and the inner ring of the thrust ball bearing 10A and the valve shaft 6S can be fitted to each other when the poppet valve 6 is completely closed so as to allow the rotor 3 to be displaced further by slipping the compression spring 7 through the compression spring 7. There is. Also, the poppet valve 6 has its valve shaft 6
S is supported by the guide 11 of the body 1. The tip of the poppet valve 6 has a conical shape and moves up and down to form a valve.

Although the rolling bearing of the ball bearing is illustrated in the illustrated example, a roller type rolling bearing may be used, and the type and structure of the rolling bearing are not limited to the illustrated example. Further, the valve is not limited to the poppet valve, and various valves can be adopted. Further, the screw provided on the rotor 3 may be formed on the inner peripheral surface of the rotor 3 and is not limited to the outer peripheral surface. The present invention is
It is intended to include all of these variations.

[0017]

Since the flow control valve provided by the present invention is configured as described above and the rotation of the poppet is eliminated, the rotational drive torque for valve operation is reduced, and the outer shape of the flow control valve can be miniaturized. it can. Further, non-rotation of the poppet can reduce wear of the flow rate control mechanism, and can improve durability and reliability. It should be noted that the reduction of the driving force also reduces the power consumption and can provide an economical flow control valve.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the basic configuration of a flow control valve provided by the present invention.

FIG. 2 is a vertical cross-sectional view showing a modified poppet of a flow control valve provided by the present invention.

FIG. 3 is a vertical sectional view showing a modified example of the flow control valve provided by the present invention.

FIG. 4 is a vertical cross-sectional view showing the configuration of a conventional flow control valve.

FIG. 5 is a vertical cross-sectional view showing a valve opening / closing state of a conventional flow control valve.

[Explanation of symbols]

1, 1A ... Body 1V ... valve mouth 2 ... Stator 3 ... rotor 3N ... female screw 4 ... Rotor magnet 5 ... Male screw 6 ... Poppet valve 6S ... Valve shaft 7 ... Compression spring 8, 9 ... Retaining ring 10, 10A ... Thrust ball bearing 11 ... Guide 12 ... Ball bearing NM ... Screw feed mechanism

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masahisa Ando             1st Nishinokyo Kuwabara-cho, Nakagyo-ku, Kyoto City Stock Association             Inside the Shimadzu factory (72) Inventor Kazushi Otono             1st Nishinokyo Kuwabara-cho, Nakagyo-ku, Kyoto City Stock Association             Inside the Shimadzu factory F term (reference) 3H062 AA02 AA15 BB10 BB30 CC02                       DD01 EE06

Claims (2)

[Claims] 1. A rotor having a screw feed mechanism in which a screw provided on a peripheral surface of a rotor of a motor and a fixed screw on a body side of a valve are screwed together, and the rotor being displaced in an axial direction by the operation of the screw feed mechanism. A flow control valve in which a valve shaft is locked to a valve, and a flow rate is controlled by displacement of the valve, wherein a rolling bearing is interposed at a locking portion between the valve shaft and the rotor. 2. The flow control valve according to claim 1, wherein the motor is a stepping motor.