JPH04315206A - Diaphragm type flow rate regulating valve - Google Patents

Abstract

PURPOSE:To prevent the influence of secondary pressure by canceling the secondary pressure loaded to a diaphragm constituting the valve body of a main valve by secondary pressure loaded to a secondary diaphragm provided on the secondary side of a flow passage in counter to the above-mentioned diaphragm with a pressure receiving plane having the almost same diameter as the valve seat diameter of this main valve. CONSTITUTION:A flow rate regulating valve A is equipped with a variable aperture pilot valve (b) and by controlling the aperture of this pilot valve (b), the aperture of a diaphragm type main valve (a) is indirectly controlled. On a secondary side 1b of the low passage, a secondary side diaphragm 4 equipped with the pressure receiving plane having the almost same diameter as the valve seat diameter of the main valve (a) is provided concentrically to the valve seat in counter to a diaphragm 2 constituting the valve body of the main valve (a). The secondary side diaphragm 4 is linked to the diaphragm 2 constituting the valve body of the main valve (a) by a linking member 5. Therefore, the secondary pressure loaded to this diaphragm 2 is canceled by the secondary pressure loaded to the secondary side diaphragm 4. Thus, the aperture of the valve A is prevented from being changed by the fluctuation of the secondary pressure.

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, particularly a diaphragm type flow control valve.

0002

[Prior Art] Various structures have been known as flow control valves, but most of them are ball valve types that directly limit the opening area, and the valves are mainly operated manually or by motor drive via a speed reducer. are doing.

0003

These conventional flow control valves that directly limit the opening area require a large operating force to control the flow rate, that is, to adjust the opening degree of the valve.

Therefore, the inventors of the present invention changed the flow rate control valve to a pilot-type diaphragm valve, and indirectly controlled the opening of the main valve by adjusting the opening of the pilot valve, thereby reducing the operating force. I came up with an idea to alleviate it.

However, since such a diaphragm type flow rate control valve operates using fluid pressure, it is easily affected by the pressure on the secondary side of the flow path (hereinafter referred to as secondary pressure). However, there was a possibility that the position of the diaphragm valve would change due to fluctuations in the secondary pressure, which caused some problems in flow rate adjustment performance.

The present invention has been made in view of the above-mentioned conventional circumstances, and its object is to provide a diaphragm type flow control valve that is less susceptible to the influence of secondary pressure.

[0007]

[Means to solve the problem]

In order to achieve the above object, the diaphragm type flow control valve of the present invention is provided with a pilot valve whose opening degree is variable, and the opening degree of the diaphragm type main valve is indirectly controlled by adjusting the opening degree of the pilot valve. A diaphragm type valve structure is formed, and a secondary side diaphragm having a pressure-receiving surface having a diameter approximately the same as the valve seat diameter of the main valve on the secondary side of the flow path is arranged opposite to the diaphragm constituting the valve body of the main valve, The secondary diaphragm is provided concentrically with the valve seat, and the secondary diaphragm is connected to the diaphragm constituting the valve body of the main valve by a connecting member.

[0009]

[Operation] In the diaphragm flow rate control valve configured as described above, the force applied by the secondary pressure to the diaphragm constituting the valve body of the main valve and the force applied to the secondary side diaphragm are of the same magnitude. The force that pushes the diaphragm of the main valve in the opening direction due to the secondary pressure is offset by the force that is applied to the secondary diaphragm and pulls the diaphragm of the main valve in the closing direction via the connecting member. The valve diaphragm is not affected by secondary pressure.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. In the figure, (A) is the main body of the flow control valve, (6) is its inlet, and (7) is its outlet.
(7) A main valve seat (3) is formed in the middle of the flow path (1) that communicates with the main valve seat (3).

Furthermore, an opening (8) is provided concentrically with the main valve seat (3) on the primary side (1a) and secondary side (1b) of the flow path (1), respectively.
)(9) is opened in the main body (A).

[0012] A lid (11) integrally equipped with a drive unit (10) for driving a pilot valve (b) to be described later is attached to the primary side opening (8), and the lid (11) and the main body are connected to each other. A diaphragm (2) is disposed facing and concentrically with the main valve seat (3), with its periphery sandwiched between the stepped portion (12) provided in (A).

This diaphragm (2) corresponds to the main valve seat (3) and constitutes the main valve (a) (hereinafter referred to as the main valve diaphragm), and behind it there is a space between it and the lid (11). A back pressure chamber (13) is formed.

The main valve diaphragm (2) has a main valve seat (3).
) In order to prevent deformation of the seating part, a contact plate (14) with a diameter slightly larger than the seat diameter of the main valve seat (3) is placed on the back side, and at a position where the main valve seat (3) is removed outwardly. Our board (1
4) and the diaphragm (2) in the form of a small hole to form a back pressure chamber (
13) and a small passage (
15) is formed.

The abutting plate (14) is provided with a protrusion (16) that passes through the center of the main valve diaphragm (2), and a protrusion (16) that passes through the center of the protrusion (16) in the axial direction. A pilot hole (17) is formed and this pilot hole (1
A pilot valve seat (18) is installed on the back pressure chamber (13) side opening edge of 7).
) is formed.

A valve body (19) constituting the pilot valve (b) corresponding to the pilot valve seat (18) extends from the drive section (10), penetrates the lid (11), and opens the back pressure chamber ( 1
3) It is integrally provided at the tip of the plunger (20) inserted into the plunger (20). The drive unit (10) includes a plunger (20) and an electric drive device such as an electromagnetic solenoid or a motor that can rotate in forward and reverse directions to move the plunger (20) forward and backward and change its forward or backward position. (21)
etc., the electric drive device is housed in the casing (22), and the plunger (20) is housed in the casing bottom plate (22).
2a) is provided through the casing (22a).
) is attached and fixed to the back of the lid (11), and the plunger (
20) is inserted into the back pressure chamber (13) of the main body (A) through the insertion hole (23) provided in the lid (11) so as to be concentric with the pilot valve seat (18), and the tip of the plunger (20) The pilot valve body (19) corresponds to the pilot valve seat (18).

On the other hand, a ring-shaped fastener (24) is screwed into the secondary opening (9), and the fastener (24) and a step (25) provided in the main body (A) The secondary side diaphragm (4) closes the secondary side opening (9) by sandwiching the peripheral edge thereof, and is arranged concentrically opposite to the main valve diaphragm (2).

The pressure receiving surface diameter AD of this secondary diaphragm (4) is formed to be approximately the same diameter as the seat diameter AS of the main valve seat (3), and the secondary diaphragm (4) is formed in the center thereof.
4) to the main valve diaphragm (2).
5) is fixed with screws (26).

The connecting member (5) has one end fixed to the center of the secondary diaphragm (4) with a screw (26), and moves in the flow path (1) toward the main valve seat (3) concentrically with the main valve seat (3). A recessed hole (27) is opened in the axial direction at the other end, and a flange (28) with a slightly smaller diameter than the main valve seat (3) is provided on the periphery, and the recessed hole (27) and the contact plate ( 14) and the protrusion (16) with the screws (29) provided on both sides, and the flange (28)
) and the contact plate (14) sandwich the main valve diaphragm (2), thereby connecting the secondary side diaphragm (4) and the main valve diaphragm (2).

A through hole (30) connecting the outside of the connecting member (5) and the inner bottom of the recessed hole (27) is opened on the circumferential side of the connecting member (5), so that the pilot hole (17) is connected to the flow path 2.
It is now possible to connect to the next side (1b).

[0021] Thus, such a flow rate control valve adjusts the pressure and back pressure on the primary side (1a) of the flow path by opening the pilot valve (b) and releasing the pressure in the back pressure chamber (13). A pressure difference with the internal pressure of the chamber (13) is generated, and the main valve (a) opens due to the pressure difference. By moving the plunger (20) back and forth and adjusting the position of the pilot valve (b), , the valve opening degree of the main valve (a) is adjusted. That is, the flow rate is adjusted.

At this time, the secondary pressure is applied to the main valve diaphragm (2
) and the secondary diaphragm (4), but since the pressure receiving surfaces of the main valve diaphragm (2) and the secondary diaphragm (4) face each other, the diaphragm (2) (4) ) They act as urging forces in opposite directions to each other.

However, the seat diameter AS of the main valve seat (3)
(The diameter of the surface where the main valve diaphragm receives secondary pressure) and the pressure receiving surface diameter AD of the secondary diaphragm (4) are almost the same diameter, so the force exerted on the main valve diaphragm (2) by the secondary pressure and the force applied to the secondary diaphragm (4) are almost equal, and since both diaphragms (2) and (4) are connected to each other by the connecting member (5), Such forces are canceled out.

Therefore, if the downstream faucet is opened and closed,
Even if the secondary pressure fluctuates, the main valve diaphragm (2) is not affected by it, and the valve opening of the main valve (a) does not change.

In this embodiment, the lid (11) of the main body (A) and the casing bottom plate (22a) of the drive section (10) are
), but the plunger (20)
However, the portion through which the seat plate (22a) and the lid (11) are inserted is not sealed, and water in the back pressure chamber (13) flows behind the plunger (20).

Next, in FIG. 3, there is basically no difference from the above embodiment, but the plunger (20) is attached to the casing bottom plate (
The part where the valve (22a) is inserted is sealed with an O-ring (31), and the diameter AP of the sealing part is set to the pilot valve seat (
18) is formed to have the same diameter as the seat diameter AR.

With this structure, the flow control valve of this embodiment cancels the force in the valve closing direction and the force in the valve opening direction applied to the plunger (20) by the water pressure in the back pressure chamber (13). This makes it possible to adjust the flow rate with a smaller operating force than in the previous embodiment.

[0028]

[Effects] As described above, the present invention includes a secondary diaphragm having a pressure receiving surface having a diameter approximately the same as the valve seat diameter of the main valve on the secondary side of the flow path, which faces the diaphragm constituting the valve body of the main valve. Since the secondary diaphragm is connected to the diaphragm constituting the valve body of the main valve by a connecting member, the secondary pressure applied to the diaphragm constituting the valve body of the main valve is on the secondary side. This is offset by the secondary pressure on the diaphragm.

Therefore, even though the valve is a diaphragm type flow control valve that uses fluid, it is not possible to obtain a high-performance flow control valve in which the opening degree of the main valve does not change due to fluctuations in the secondary pressure. can.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a diaphragm flow control valve showing one embodiment of the present invention.

FIG. 2 is a sectional view showing the main parts in a state where the valve is closed.

FIG. 3 is a sectional view showing another embodiment.

[Explanation of symbols]

a: Main valve b: Pilot valve 1: Flow path 1a: Flow path primary side 1b: Flow path 2
Next side 2: Diaphragm that constitutes the valve body of the main valve (main valve diaphragm) 3: Main valve seat 4: Secondary side diaphragm 5
:Connection member

Claims (1)

[Claims] 1. A diaphragm type flow control valve comprising a pilot valve with a variable opening degree, and indirectly controlling the opening degree of a diaphragm type main valve by adjusting the opening degree of the pilot valve, wherein the valve is provided on the secondary side of a flow path. A secondary diaphragm having a pressure-receiving surface of approximately the same diameter as the valve seat diameter of the main valve is provided concentrically with the valve seat, facing the diaphragm constituting the valve body of the main valve. A diaphragm type flow control valve, characterized in that it is connected to a diaphragm constituting a valve body of the valve through a connecting member.