JPH04275609A - Flow rate controller - Google Patents

Abstract

PURPOSE:To completely preclude the danger of a leak of working liquid in the liquid chamber of a piezoelectric actuator by determining the reference positions of a pilot valve and a pilot valve seat by a position adjusting mechanism provided to a pilot valve seat body. CONSTITUTION:The pilot valve main body 10 consists of the pilot valve body 11, a hemispherical pilot valve 13 provided at one end of this pilot valve body 11, a pilot valve seat 14 facing the pilot valve 13, and a pilot valve seat body 15 constituting the pilot valve seat 14. The pilot valve seat body 15 is provided with the position adjusting mechanism. A male screw part 15-1 is formed at the outer periphery of the pilot valve seat body 15 as this position adjusting mechanism and the reference positions of the pilot valve seat 14 and pilot valve 13 are adjusted. Consequently, the danger of the leak of the liquid charged in the liquid chamber of the piezoelectric actuator 12 can completely be precluded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow control device, and more particularly to a flow control device using an externally piloted valve.

0002

2. Description of the Related Art Conventionally, an actuator such as that disclosed in Japanese Patent Application No. 1-290879 has been used as an actuator for an external pilot type flow control valve. This actuator is configured to expand the displacement of a piezoelectric element via an input piston and a liquid sealed in a liquid chamber and convert it into displacement of an output piston, and the output piston comes into contact with a pilot valve body to drive the pilot valve. . In addition, this actuator is constructed by fitting a sealing body that is movable in the direction of the liquid chamber in close contact with a through-hole for liquid sealing that communicates the liquid chamber with the outside. , the reference position of the output piston of this piezoelectric actuator is adjusted. The reference position of the output piston is adjusted by providing an adjusting screw that biases the sealing body and moving the sealing body forward toward the liquid chamber by turning this adjusting screw.

0003

[Problems to be Solved by the Invention] However, as mentioned above, when adjusting the water stop position using a piezoelectric actuator, the sealing body that is the position adjustment mechanism is provided in the through hole that communicates the liquid chamber with the outside. Therefore, there is a risk that the working fluid inside the fluid chamber may leak. Further, since the position of the output piston is adjusted only by advancing the sealing body toward the liquid chamber, if it is moved too far forward, the position of the output piston cannot be corrected any longer.

0004

Means for Solving the Problems In order to solve the above problems, a flow rate regulating device according to the present invention is characterized in that a position adjustment mechanism is provided on the pilot valve seat body.

[0005]

[Operation] The flow rate regulating device according to the present invention adjusts the reference positions of the pilot valve seat and the pilot valve using a position adjustment mechanism provided on the pilot valve seat body.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view of a flow rate regulating device according to an embodiment of the present invention. The flow rate adjustment device 1 includes casings 2 and 3.
, a diaphragm valve 6 provided between the inflow passage 4 and the outflow passage 5, a diaphragm back chamber 8 formed on the back surface of the diaphragm valve 6 so as to communicate with the inflow passage 4 via a bleed hole 7, and this diaphragm valve 6. A pilot valve body 10 provided between the back chamber 8 and an external pilot chamber 9 which is an open space to the atmosphere, and a pilot valve body 11 of the pilot valve body 10.
The piezoelectric actuator 12 is configured to drive a piezoelectric actuator 12.

The pilot valve body 10 includes a pilot valve body 11, a hemispherical pilot valve 13 provided at one end of the pilot valve body 11, a pilot valve seat 14 facing the pilot valve 13, and a pilot valve seat 14. The pilot valve seat body 15 is supported by the casing 2 in a fluid-tight manner. Note that 16 indicates a discharge flow path that communicates the diaphragm back chamber 8 with the external space.

As the piezoelectric actuator 12, a piezoelectric actuator 12, which has been used in the past and is disclosed in Japanese Patent Application No. 1-290879, has an input piston and a liquid chamber sealed in the piezoelectric element so that the displacement of the piezoelectric element is controlled by applying electric power to the piezoelectric element. Although a device that converts the displacement of the output piston into the displacement of the output piston via the liquid may be used, it is not necessary to provide a sealing body, which is a position adjustment mechanism, in the through hole that communicates the liquid chamber with the outside. In addition, in the figure,
12-1 is a piezoelectric element, 12-2 is its power supply line, 12
-3 is an input piston, 12-4 is a liquid chamber, 12-5 is a bellows, and 12-6 is a diaphragm.

In this embodiment, a male threaded portion 15-1 is formed on the outer periphery of the pilot valve seat body 15 as a position adjustment mechanism, and a notch 1 is provided at the bottom as shown in FIG.
7, and by turning this notch 17 to the right or left, the pilot valve seat body 15 (i.e., the pilot valve seat 14
) can move forward or backward relative to the pilot valve main body 10, which has a female threaded portion 10-1 on the inner peripheral surface that is screwed into a male thread formed on the outer periphery of the pilot valve seat body 15. Note that a pilot valve guide 22 provided to cover the pilot valve body 11 is fixed to the pilot valve seat body 15, and the pilot valve body 11 slides along this pilot valve guide 22.

Adjustment of the reference positions of the pilot valve 13 and the pilot valve seat 14 of the flow rate regulating device having such a configuration is as follows.
By turning the notch 17 using a screwdriver or the like, the pilot valve seat body 15 is raised and lowered to open the pilot valve 1.
3 and the pilot valve seat 14. By doing so, the position can be adjusted regardless of the amount of protrusion of the output piston 18 protruding from the piezoelectric actuator 12.

After determining the reference position of the pilot valve seat body 15 through this adjustment, the valve body 19 enclosed by the casing 3 is attached to the lower part of the pilot valve body 10 to complete the valve. In the above configuration, when no voltage is applied to the piezoelectric actuator 12, the pilot valve body 11 is pushed by the output piston 18, and the pilot valve 13 comes into contact with the pilot valve seat 14, and the pilot valve hole 2
Therefore, the diaphragm valve 6 is closed by the pressure of the fluid flowing into the diaphragm back chamber 8.

On the other hand, when the piezoelectric actuator 12 is driven to move the output piston 18 backward, the pilot valve 13 is separated from the pilot valve seat 14 and the pilot valve hole 20 is opened. Then, the fluid in the diaphragm back chamber 8 flows into the external pilot chamber 9 and further flows out to the outside of the casing 2 via the discharge flow path 16. This allows the diaphragm back chamber 8
, the pressure from the inlet passage 4 pushes up the diaphragm valve 6, and water begins to flow to the outlet passage 5. By adjusting the voltage applied to the piezoelectric actuator 12, the amount of movement of the output piston 18, that is, the amount of movement of the pilot valve body 11 is adjusted, and the flow rate of the fluid flowing through the valve hole 21 is adjusted. When the output piston 18 is moved back and forth repeatedly in this manner, there is a risk that the sealed liquid will leak in the actuator used in the conventional flow rate adjusting device described above, but the flow rate adjusting device according to the present invention has the risk of leaking liquid. It is not necessary to use actuators that are dangerous. Furthermore, if the reference position shifts due to use, the valve body 1
By removing 9, the reference positions of the pilot valve 13 and the pilot valve seat 14 can be easily adjusted.

[0013]

Effects of the Invention The flow rate adjusting device according to the present invention determines the reference positions of the pilot valve and the pilot valve seat by the position adjustment mechanism provided on the pilot valve seat body, so that the working liquid inside the liquid chamber of the piezoelectric actuator is There is no risk of leakage, and the structure can be simplified. Further, since the position adjustment mechanism can move not only forward but also backward, the position can also be corrected.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a flow rate regulating device according to an embodiment of the present invention.

FIG. 2 is an enlarged bottom view of a pilot valve seat body as a position adjustment mechanism of a flow rate adjustment device according to an embodiment of the present invention.

[Explanation of symbols]

1...Flow control device, 2, 3...Casing, 4...Inflow path,
5...Outflow path, 6...Diaphragm valve, 7...Bleed hole, 8
...Diaphragm back chamber, 9...External pilot chamber, 10...Pilot valve body, 10-1...Female screw portion, 11...Pilot valve body, 12...Piezoelectric actuator, 12-1...Piezoelectric element, 12-2...Power supply line , 12-3...input piston,
12-4...Liquid chamber, 12-5...Bellows, 12-6...Diaphragm, 13...Pilot valve, 14...Pilot valve seat, 15...Pilot valve seat body, 15-1...Male thread part, 1
6... Discharge flow path, 17... Notch, 18... Output piston,
19... Valve body, 20... Pilot valve hole, 21... Valve hole, 22... Pilot valve guide.

Claims (1)

[Claims] Claim 1: A diaphragm valve provided between an inflow passage and an outflow passage so as to be freely openable and closable; a diaphragm back chamber formed on the back surface of the diaphragm valve so as to communicate with the inflow passage through a bleed hole; Equipped with a pilot valve hole to release the fluid to the outside or the outflow path side,
The flow rate of the fluid flowing through the pilot valve hole is controlled by the clearance between the pilot valve body and the pilot valve seat, and the flow rate flowing from the inflow path side to the outflow path side is adjusted, and the displacement of the piezoelectric element is input to the piston and the liquid sealed in the liquid chamber. A flow rate adjustment device operated by a piezoelectric actuator configured to convert the displacement of an output piston into a displacement of an output piston, characterized in that a position adjustment mechanism is provided on a pilot valve seat body constituting a pilot valve seat. Device.