JPH07180773A - Minute flow rate regulating valve - Google Patents

Abstract

PURPOSE:To easily work a groove part for regulating a minute flow rate, reducing a cost, and to maintain regulating function and blocking function for the minute flow rate for a long period. CONSTITUTION:In a cylindrical opening part 5 which is formed in a contraction pipe 13 installed on a bulk-head 4, a cylindrical control valve 12 formed integratedly with a closing valve 10 is inserted, and it can be slid in vertical direction together with the closing valve 10. On a part of the circumferential surface of the control valve 12, a groove 12a whose cross section is formed in the shape of an arc having a constant diameter and whose depth is changed is formed by using, for example, an end mill, a milling cutter, and the like, and the sectional area of a flow passage formed toward the opening part 5 is minutely changed continuously by the vertical movement of the control valve 12. It is thus possible to minutely change the flow rate of fluid which flows in from an inlet flow passage 2 according to the effective sectional area of the groove 12a. When the sitting part 11 of the closing valve 10 is brought in contact with the valve seat part 14 of a bulk-head 4, completely closed valve condition is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a minute flow rate control valve used in a fluid transportation pipe which requires a minute amount of flow rate control.

[0002]

2. Description of the Related Art The present applicant has previously filed a patent on the invention of a control valve which can obtain a flow rate characteristic with high accuracy by adopting a control valve having a collar portion and can control a wide range from a minute flow rate to a large flow rate. Filed an application (JP-A-4-2)
36861). However, recently, there is a growing need for control of a minute flow rate, and the structure according to the invention of the prior application has a limit in the size of the collar portion.
It has been found that it is difficult to make a minute flow rate adjustment.

On the other hand, as a control valve for adjusting a minute flow rate, a cylindrical plug having a V-shaped notch on a part of its peripheral surface is slidably fitted into the opening of the seat ring to open the notch. The one that regulates the flow rate is often adopted.

FIG. 4 shows a vertical cross section of a plug and a seat ring in an example of a conventional control valve. A V-shaped notch 21a is formed on the peripheral surface of a small diameter portion of a cylindrical plug 21 having a step. It is provided and inserted into the inner hole of the seat ring 22. 5 (a) and 5 (b) are cross-sectional views of a conventional plug having a V-shaped notch.
Since the cross-sectional area of the conventional V-shaped notch 21a is changed depending on the groove width L, the groove depth H is constant.

When the plug 21 is moved up and down, the groove width of the V-shaped notch 21a changes and the flow rate is continuously adjusted. Further, the stepped portion of the plug 21 has a tapered seat portion 2
1b is provided, and the valve is configured to be fully closed by seating and pressing the same on a valve seat portion 22a of the same taper provided on the seat ring 22 side.

[0006]

In the conventional control valve described above, since the opening area of the fluid passage portion is adjusted by the groove width L of the V-shaped notch 21a formed in the plug 21, a minute opening is formed. In order to obtain the area, it is necessary to perform precision grinding of the V-shaped notch 21a with a special cutting tool, which causes a problem that a lot of labor and cost are required for processing.

In order to completely close the valve, the seat portion 21b of the plug 21 and the valve seat portion 22 of the seat ring 22 are required.
It is necessary to rub the a by rubbing to rub the contact surface, which is not only difficult to process and requires high accuracy, but also the contact surface is damaged due to repeated valve opening and closing operations.
There was a problem that it could not be closed or adjusted.

The present invention has been made in view of the problems of the prior art as described above, and an object thereof is to make it possible to easily and inexpensively process a groove portion for adjusting a minute flow rate, and to make a minute groove for a long time. An object of the present invention is to provide a minute flow rate control valve capable of maintaining the flow rate control function and the valve closing function.

[0009]

A structure of the present invention for solving the above problems will be described with reference to FIG. 1 corresponding to an embodiment of the present invention. The minute flow rate control valve of the present invention includes a valve body 1
A partition wall 4 provided between the inner inlet flow path 2 and the outlet flow path 3 to bend the flow direction, and an opening provided in the partition wall 4 to communicate the inlet flow path 2 and the outlet flow path 3 Part 5 and
A shutoff valve 10 disposed opposite to the opening,
The shut-off valve 10 has a lower end arranged coaxially with the axis of the opening 5, slidably fitted in and supported by the opening 5, and has a cross-sectional area proportional to the tip on the peripheral surface. A control valve 12 having a groove 12a having an arcuate cross section for increasing the flow rate is provided in a protruding manner, and the shutoff valve 10 is vertically movable and its lower end surface is formed around the opening 5. Valve seat 1
It is characterized in that it can come into contact with No. 4.

The material of the minute flow rate control valve of the present invention may be plastic or metal and is not particularly limited. In addition, the direction of inflow and outflow of the fluid is not limited, and the fluid can be introduced from either side of the valve, and there is no difference in the adjusting function thereof.

[0011]

The operation of the present invention having the above construction will be described based on the minute flow rate control valve shown in FIG. 1 (valve open state) and FIG. 2 (valve closed state). In FIG. 1, the fluid that has flowed in via the inlet flow passage 2 is controlled by the arcuate groove 12 a formed in the opening 5 and the peripheral surface of the control valve 12 and flows out to the outlet flow passage 3.

When the shut-off valve 10 is moved toward the opening 5 (downward in the figure), the control valve 12 also moves downward, following the arc-shaped groove 12a and the opening 5.
Since the opening area of the fluid passage portion formed by and becomes proportionally smaller, the flow rate decreases in proportion to the moving amount of the control valve 12. Conversely, when the stop valve 10 is moved in a direction away from the opening 5 (upward in the figure), the opening area of the fluid passage portion increases proportionally, and the flow rate increases in proportion to the moving amount of the control valve 12. To increase. In this way, the minute flow rate of the fluid is adjusted in proportion to the moving amount of the control valve 12.

When the closing valve 10 is continuously moved in the direction of the opening 5, the seating portion 11, which is the lower end surface of the closing valve 10, finally comes into contact with the valve seat portion 14 around the opening 5 and is pressed. . Therefore, the space between the inlet flow passage 2 and the outlet flow passage 3 is completely closed, and the valve is closed. (State of Figure 2)

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing an embodiment of the present invention. In FIG. 1, reference numeral 1 is a valve main body, inside of which a partition wall 4 for partitioning an inlet passage 2 and an outlet passage 3 is provided. A curved flow path is formed between the flow paths 2 and 3. A valve chamber 8 is formed inside the valve body 1 in a direction perpendicular to the axes of the inlet passage 2 and the outlet passage 3.
A stop valve 10 is arranged in the valve chamber 8.

The partition wall 4 is provided with a cylindrical opening 5 which connects the inlet passage 2 and the outlet passage 3 with each other. This opening 5
Specifically, it is formed by penetrating the contraction tube 13 screwed and bonded to the partition wall 4.

The contraction pipe 13 has a valve seat portion 14 made of an elastic body for sealing which is fitted and adhered to an upper outer peripheral surface of the contraction pipe 13 and is provided on a partition wall 4 which separates the inlet passage 2 and the outlet passage 3 from each other. The valve seat portion 14 is screwed and adhered to a large opening having a female screw portion as a part thereof so as to sandwich the valve seat portion 14. In the present embodiment, the opening 5 is provided by screwing and adhering the contraction pipe 13 into the valve body 1, but it may be provided by directly opening the partition wall 4.

The shut-off valve 10 is integrally formed on the lower end portion of the valve shaft 9 held by the lid body 7 fixed to the upper portion of the valve body 1, and the axis line of the valve shaft 9 is aligned with the axis line of the opening 5. The valve body 1 is airtightly fitted in a valve chamber 8 formed by a neck portion 6 located above the valve body 1, and is held so as to be movable back and forth in the vertical direction. An annular seat 11 is formed around the lower end of the stop valve 10 so as to be able to contact the valve seat 14.

Reference numeral 12 denotes a control valve, which is screwed and adhered to the lower end of the shutoff valve 10 so that the axis of the opening 5 coincides with the axis thereof and is slidably and airtightly fitted in the opening 5. While being fitted and supported, a groove 12a having an arc-shaped cross section for adjusting the flow rate is formed on the peripheral surface so that the cross-sectional area increases proportionally toward the tip.

3A and 3B are cross-sectional views of the control valve 12 including the arcuate groove 12a, and FIG. 3A is the arcuate groove 1
2A shows a cross section in the vicinity of the position where the cross sectional area is maximum, while FIG. 2B shows a cross section at a position which is 1/10 of the cross sectional area in the case of FIG.

The arcuate groove 12a is an arcuate groove having the same radius R, and is formed so that the cross-sectional area increases proportionally by changing the length of the arc and the depth of the groove. The cross-sectional area of the arcuate groove 12a in FIG. 3 (a) is substantially equal to the cross-sectional area of the notch 21a in FIG. 5 (a) showing the conventional example. The area is approximately equal to the cross-sectional area of the cutout in FIG.

In this embodiment, the arcuate groove 12a is formed by a method in which the depth of cut is gradually increased using an end mill having a hemispherical tip or a milling cutter having an arcuate outer edge. They may be formed at the same time when the control valve 12 is molded by injection molding or the like.

In this embodiment, one arcuate groove 12a is provided, but two or more arcuate grooves 12a may be provided in parallel. Further, the control valve 12 may be integrally formed on the lower end portion of the shutoff valve 10.

The operation of the minute flow rate control valve of the present embodiment having the above structure is as follows. In FIG. 1, the fluid that has flowed in through the inlet channel 2 is the opening 5 and the control valve 1.
It is controlled by the arcuate groove 12a formed on the peripheral surface of No. 2 and flows out to the outlet channel 3. Here, when the stop valve 10 is moved toward the opening 5 via the valve shaft 9 by actuation or manual operation of the drive unit by the automatic control device, the control valve 1
2 also follows this and moves. Accordingly, the arcuate groove 12
Since the opening area of the fluid passage portion formed by a and the opening portion 5 becomes proportionally smaller, the flow rate decreases proportionally to the moving amount of the control valve 12. On the contrary, when the stop valve 10 is moved in the direction away from the opening 5, the opening area of the fluid passage portion is proportionally increased, and the flow rate is increased proportionally to the movement amount of the control valve 12. In this way, the minute flow rate of the fluid is adjusted by proportionally increasing or decreasing with respect to the movement amount of the control valve 12.

When the closing valve 10 is continuously moved in the direction of the opening 5, the seating portion 11, which is the lower end surface of the closing valve 10, finally comes into contact with the valve seat portion 14 around the opening 5 and is pressed. As a result, the space between the inlet passage 2 and the outlet passage 3 is completely closed, and the flow of fluid is stopped. This state is shown in FIG. With the above-mentioned actions, the flow rate of the fluid is continuously and minutely adjusted, and the valve is completely closed.

[0025]

The following effects can be obtained by using the minute flow rate control valve of the present invention described above. Since the arcuate groove capable of proportionally increasing and decreasing the minute flow rate can be formed easily and inexpensively, the labor and cost for processing can be significantly reduced, and it is economical. Since there are no troublesome tapered seats and valve seats that require machining and rubbing, it can be manufactured easily and inexpensively, and the contact surface is not easily damaged by repeated valve opening and closing operations. Therefore, the function of adjusting the minute flow rate and the function of closing the valve can be maintained for a long period of time.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view including a partial front view showing an embodiment of a minute flow rate control valve of the present invention.

FIG. 2 is a vertical sectional view showing a fully closed state of the minute flow rate control valve in FIG.

3 is a cross-sectional view of the control valve including the arcuate groove portion in FIG.

FIG. 4 is a front view including a partial cross-sectional view showing a main part of a plug and a seat ring in a conventional minute flow rate control valve.

FIG. 5 is a cross-sectional view of a conventional plug having a V-shaped notch.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Valve main body 2 ... Inlet flow path 3 ... Outlet flow path 4 ... Partition wall 5 ... Opening part 6 ... Neck part 7 ... Lid body 8 ... Valve chamber 9 ... Valve shaft 10 ... Stop valve 11 ... Seating part 12 ... Control valve 12a ... Arc-shaped groove 13 ... Contraction pipe 14 ... Valve seat 21 ... Plug 21a ... V-shaped notch 21b ... Tapered seat 22 ... Seat ring 22a ... Tapered valve seat

Claims (1)

[Claims] 1. A partition wall provided between an inlet flow path and an outlet flow path inside the valve body to bend the flow direction, and a partition wall provided in the partition wall to communicate the inlet flow path and the outlet flow path. An opening portion and a shutoff valve disposed so as to face the opening portion are provided, and a lower end of the shutoff valve is disposed coaxially with an axis line of the opening portion and slidably in the opening portion. Fitted and supported, a control valve with a groove with an arcuate cross-section for adjusting the flow rate, whose cross-sectional area increases proportionally toward the tip, is protrudingly provided on the peripheral surface, and the stop valve moves up and down. A minute flow rate control valve, which is capable of contacting a lower end surface thereof with a valve seat portion formed around the opening.