JP2004052797A - Flow control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow control valve using a less number of component parts, capable of reducing the manufacturing cost owing to a less number of processing and assembly processes, and excellent in the regulating accuracy for the rate of flow. <P>SOLUTION: The flow control valve includes a motor 4 installed in a cover of a valve box consisting of a base 2 and a cover 3 mounted thereon, and a feed screw part is formed by direct processing on a downward protruding rotary shaft 5 of the motor, and a space 2a penetrating crosswise is formed in the base. In this space, a tube 7 as flow passage is installed whose section shape deforms when pressed in the radial direction but restitutes with its elastic restoring force, and a vertical hole 10 is provided in the center of the base, and in the vertical hole, an elevating body 11 is installed, which is furnished with a nut part 15 where a screw part of a motor rotary shaft is engaged and at the bottom, with a push stop piece 16 confronting the upper side face of the tube, and the tube 7 is pushed in the radial direction by a bottom push stop piece of the elevating body moving in the vertical direction with the regular and reverse operations of the motor and also the pushing force is released. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a flow control valve.
[0002]
[Prior art]
Among flow control valves, there is a type in which a motor provided in a valve box is driven forward and reverse to move a valve body up and down to adjust a flow rate.
[0003]
In this type of conventional type, a screw shaft is attached to the rotating shaft of the motor with various joints, a nut is screwed on this screw shaft, the nut is raised and lowered by forward and reverse rotation of the screw shaft, and a valve body that is integral with the nut The valve hole is opened / closed or throttled to open / close and throttle the valve hole.
[0004]
Such a conventional device requires a joint for connecting the motor rotation shaft and the screw shaft, and also requires a valve seat for the valve hole and sealing means for closing the valve hole. The number of processes increases and the manufacturing cost increases.
[0005]
[Object of the present invention]
The present invention can provide a flow control valve which has a small number of parts, a small number of processing and assembling steps, can reduce manufacturing costs, and has excellent control accuracy.
[0006]
[Means of the present invention]
In order to achieve the above object, a flow control valve of the present invention is provided with a motor in a cover of a valve box including a base body and a cover attached thereto, and a feed screw portion is directly provided on a downwardly projecting rotation shaft of the motor. Processed and formed a space part penetrating in the lateral direction in the base body, the cross-sectional shape is deformed by being pressed in the radial direction in the space part, but a flow path tube having elastic restoring force is formed. In addition, a vertical hole is formed in a central portion of the base body, an elevating body is provided in the vertical hole, a nut portion with which a screw portion of the motor rotating shaft is screwed is provided on the elevating body, and the tube is provided at a lower end. A pressing body facing the upper side is provided, and the lower pressing body of the lifting body which is moved up and down by forward and reverse driving of the motor presses the tube in the radial direction or releases the pressing force, Use a stepping motor for the motor. The feed screw mechanism consisting of the nut unit screwed to the threaded portion and threaded portion of the rotating shaft are constituted by a ball screw means.
[0007]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to a specific example shown in the accompanying drawings.
The flow control valve 1 of the present invention shown in FIGS. 1 and 2 has a valve body case 3 attached to a base body 2, and a motor 4 is provided by a stay 6 in an upper space in the case. The rotary shaft 5 is directly threaded.
[0008]
The base body 2 has a space portion 2a penetrating in the lateral direction, and a flow rate control tube 7 is disposed in the space portion 2a, and both ends of the tube are connected through joints 8a and 8b. It is connected to the outflow pipe 9b.
[0009]
Thus, the tube 7 is preferably made of a material having elastic restoring force and having corrosion resistance to chemical fluids, for example, a tube made of a fluororesin-based copolymer.
[0010]
A vertical hole 10 is formed in the base body 2, and an elevating body 11 is fitted into the vertical hole 10 so as to be vertically movable. The elevating body 11 has a vertical hole 12 formed in an upper flange 11 a. A guide pin 13 provided on the upper surface of the base body 2 is fitted so as to be movable only in the vertical direction.
[0011]
A vertical hole 14 is formed in the center of the elevating body 11, and a nut 15 is fitted and fixed in this vertical hole, and the rotary screw shaft 5 of the motor is screwed into this nut. At the lower end, a pressing body 16 facing the upper side surface of the tube 7 is provided.
[0012]
The motor 4 is a stepping motor, and a screw formed directly on the rotating shaft of the motor is a ball screw as shown in FIGS. 3 and 4, and a nut also has a loop path 18 for circulating the ball 17.
[0013]
In the above-described flow control valve of the present invention, the elevating body 11 is screwed downward by forward rotation of the motor, and the pressing body 16 at the lower end gradually crushes the tube, thereby narrowing the flow path in the tube, or Completely crush and close the channel.
[0014]
By rotating the motor in the reverse direction, the lifting body 11 is screwed upward, the pressing force of the pressing body 16 against the tube 7 is gradually released, and the tube is expanded by its own restoring force and the pressure of the fluid in the tube. Therefore, the flow path becomes large.
[0015]
Therefore, in the flow rate control valve of the present invention, the flow path tube is pressed by the forward / reverse rotation of the motor, or the pressing force is released, the flow path area of the tube is set as required, and the opening and closing of the flow path and the flow rate can be adjusted. .
[0016]
In addition, by using a stepping motor as the motor, the vertical movement of the elevating body can be finely adjusted to finely deform the cross-sectional shape of the tube by the pressing body, and the flow rate can be adjusted. By using a ball screw mechanism as the nut to be screwed, screw feed with almost no backlash can be performed, and fine adjustment of the flow rate can be performed accurately.
[0017]
Furthermore, the state in which the flow path is completely closed by the pressing body (zero flow rate point) can be known by detecting the state in which the shaft does not rotate even when the driving power is supplied to the motor, and the state in which the shaft cannot rotate. By further supplying drive power to the motor, the flow path can be completely closed.
[0018]
Specifically, the motor is a stepping motor, and its rotation position and rotation speed are detected by an encoder, so that the shaft cannot rotate even when a drive pulse is supplied to the motor, that is, the step-out state is determined by the encoder. By detecting this step-out state, it is possible to know that the flow path is completely closed by the pressing body (flow rate zero point). By supplying, the flow path can be completely closed.
[0019]
In addition, since the screw part for screw feed is formed by directly processing the rotary shaft of the motor, it is not necessary to attach the screw shaft to the motor rotary shaft with a joint as in the past, and the number of parts can be reduced and the assembly can be reduced. Since the number of mounting steps can be reduced, and the flow rate adjusting section main body is formed of a tube, there is no need to form a valve hole and a valve seat which require precision in the base main body, and the manufacturing cost can be reduced much more than the conventional one. There are advantages.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional front view showing an embodiment of a flow control valve according to the present invention.
FIG. 2 is a vertical sectional front view showing a state in which a flow path is narrowed in the embodiment of the flow control valve according to the present invention.
FIG. 3 is a longitudinal sectional view showing an example of a ball screw.
FIG. 4 is a cross-sectional view showing an example of a hole screw.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Flow control valve 2 Base body 3 Valve case 4 Motor 5 Rotating shaft 6 Stay 7 Tube 8a, 8b Joint 9a Inflow pipe 9b Outflow pipe 10 Vertical hole 11 of base body Lifting body 12 Vertical hole 13 of flange of lifting body 13 Guide pin 14 Vertical hole of lifting body 15 Nut 16 Retainer 17 Ball 18 Loop path

Claims (3)

A motor is provided in the cover of the valve box consisting of the base body and the cover attached to the base body, the feed screw part is formed directly on the downwardly projecting rotation shaft of the motor, and the base body has a space penetrating in the lateral direction. Formed, the cross-sectional shape is deformed by being pressed in the radial direction in the space, but a tube for flow path having elastic restoring force is provided, and a vertical hole is formed in the center of the base body. An elevating body is provided in the vertical hole, a nut part with which the screw part of the motor rotating shaft is screwed is provided on the elevating body, and a pressing body facing the upper surface of the tube is provided at the lower end, and the motor is driven in the forward and reverse directions. A flow control valve that presses the tube in the radial direction with the lower end pressing body of the elevating body that is moved up and down by the valve or releases the pressing force. A flow control valve, wherein the motor according to claim 1 is a stepping motor. 2. A flow control valve according to claim 1, wherein the screw portion of the motor rotation shaft and the nut portion screwed to the screw portion are constituted by ball screw means.

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