JPH11265216A - Pressure type flow controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure type flow controller in which different kinds of flow rates can be easily obtained. SOLUTION: In this pressure type flow controller, a restriction mechanism is provided on the downstream side from a fluid control valve, and the flow control of gas is operated in a state that a pressure on the upstream side from the restriction mechanism is held about two times or more as high as the pressure on the downstream side. The venture mechanism is constituted of a first restriction mechanism member 21 having plural holes 23-25 in different sizes which are arranged in a fixed direction, and a second restriction mechanism member 21 having one hole 26 larger than the holes 23-25 which is moved in the arraying direction in contact with the first restriction mechanism member 21. The position of the hole 26 of the second restriction mechanism member 22 is matched with one of the positions of the plural holes 23-25 of the first restriction mechanism member 21 so that an aperture in the restriction mechanism can be set.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure type flow control device for controlling the flow rate of a fluid such as a gas, and more particularly, to a throttle mechanism provided downstream of a fluid control valve, and a pressure upstream of the throttle mechanism is reduced. The present invention relates to a pressure-type flow control device that controls the flow rate of gas while maintaining the pressure at about twice or more the pressure on the side.

[0002]

2. Description of the Related Art One of the characteristics of gas flow through a nozzle is a pressure ratio P ₂ / upstream pressure P ₁ and downstream pressure P ₂ of the nozzle.
P ₁ is the critical pressure ratio of the gas (approximately 0.
When the value of 5) is 0.5 or less, the flow velocity of the gas passing through the nozzle becomes a sonic velocity, the pressure fluctuation on the downstream side of the nozzle does not propagate to the upstream side, and a stable mass flow rate corresponding to the state on the upstream side of the nozzle is obtained. There are things that can be done.

As an apparatus utilizing the above-mentioned phenomenon, for example, JP-A-8-335117 and JP-A-8-33854
There is a pressure-type flow control device disclosed in, for example, Japanese Patent Application Laid-Open Publication No. 6-206.
This pressure type flow control device is provided with a throttle mechanism downstream of the fluid control valve, and controls the flow rate of the fluid while maintaining the pressure on the upstream side of the throttle mechanism at about twice or more the pressure on the downstream side. Therefore, there is an advantage that the flow rate control can be performed with higher accuracy than a conventional fluid control device such as a mass flow controller.

[0004]

However, in the pressure type flow rate control device described in the above publication, the aperture diameter in the throttle mechanism is single and fixed, so that
There was an inconvenience that only a specific flow rate could be set.

The present invention has been made in consideration of the above-mentioned matters, and an object of the present invention is to provide a pressure type flow control device which can easily obtain various different flow rates.

[0006]

In order to achieve the above object, according to the first aspect of the invention, a throttle mechanism is provided downstream of the fluid control valve, and the pressure on the upstream side of the throttle mechanism is reduced by the pressure on the downstream side. A pressure-controlled flow rate control device for controlling the flow rate of gas while maintaining the pressure at about twice or more, a first throttle mechanism member having the throttle mechanism in a state in which a plurality of holes having different sizes are arranged in a certain direction. And a second diaphragm mechanism member having one hole larger than the hole and moving in the arrangement direction while being in close contact with the first diaphragm mechanism member, and the position of the hole in the second diaphragm mechanism member. Is adjusted to one of the plurality of holes of the first aperture mechanism member to set the aperture diameter of the aperture mechanism.

In the pressure type flow rate control device having the above-described structure, by selectively moving the second throttle mechanism member, only one of the plurality of holes of the first throttle mechanism member is selectively opened. And a flow rate set based on the cross-sectional area of the hole is obtained.

According to the second aspect of the present invention, a throttle mechanism is provided on the downstream side of the fluid control valve, and the gas flow rate is maintained while maintaining the pressure on the upstream side of the throttle mechanism at about twice or more the pressure on the downstream side. In the pressure-type flow rate control device that performs control, the throttle mechanism has a first throttle mechanism member having a plurality of holes having different sizes, and a plurality of holes larger than the holes,
A second aperture mechanism member that moves while being in close contact with the first aperture mechanism member, and positions the holes of the second aperture mechanism member in at least one of the plurality of holes of the first aperture mechanism member. By adjusting the position, the hole diameter in the aperture mechanism is set.

In the pressure-type flow rate control device having the above-described structure, the second throttle mechanism member is appropriately moved so that one of the plurality of holes of the first throttle mechanism member or a state in which these are combined appropriately. It can be opened and a flow rate set based on the sum of the cross-sectional areas of the opened holes is obtained.

According to the third aspect of the present invention, a throttle mechanism is provided on the downstream side of the fluid control valve, and the gas flow rate is maintained while maintaining the pressure on the upstream side of the throttle mechanism at about twice or more the pressure on the downstream side. In the pressure type flow control device for controlling, a plurality of the throttle mechanisms are formed so as to be in parallel with each other, an on-off valve is connected to each of the throttle mechanisms in series, and the downstream side of each on-off valve is united. Have joined.

In the pressure type flow control device having the above-described structure, by opening the on-off valve, gas flows through one or a plurality of throttle mechanisms, and the gas is connected in series with the on-off valve in the open state. The flow rate set based on the total cross-sectional area of the throttle mechanism is obtained.

According to the pressure type flow control device of the present invention,
A number of different flow rates can easily be set.

[0013]

Embodiments of the present invention will be described with reference to the drawings. 1 and 2 show a first embodiment of the present invention. First, FIG. 1 shows an example of a pressure type flow control device of the present invention. In this figure, 1 is a rectangular parallelepiped main body block, for example, made of a material having chemical resistance, for example, stainless steel. This body block 1
At the left and right ends, joint blocks 2 and 3 for introducing and discharging a fluid such as a gas are integrally connected to each other by welding. These joint blocks 2 and 3 are also made of, for example, stainless steel.

A gas flow path 4 is formed inside the main body block 1 so that the upstream side is connected to the joint block 2 and the downstream side is connected to the joint block 3. The valve 5, the pressure sensor 6, and the throttle mechanism 7 are provided in this order. The flow path 4
Is a flow path 4a from the inlet of the joint block 2 to the fluid control valve 5, and a flow path 4b from the fluid control valve 5 to the throttle mechanism 7.
And the flow path 4 from the throttle mechanism 7 to the outlet of the joint block 3
c.

The fluid control valve 5 is configured as follows. That is, an orifice block 10 having a valve port 8 and a flow path 9 connected to the downstream gas flow path 4b is provided in the upstream gas flow path 4a extending on the upper surface side of the main body block 1. In addition, a valve body 13, which comprises a valve head 11 and a plunger portion 12 and adjusts the opening of the valve port 8, is provided with the valve head 11 close to the valve port 8. Normally, the valve body 13 has a slight gap between the valve body 13 and the upper surface of the orifice block 10 by a metal diaphragm 15 provided in a lower space of a valve block 14 provided above the main body block 1. So that
It is held up and down freely.

Reference numeral 16 denotes a piezoelectric element-type actuator for driving the valve 13 in the vertical direction, and is housed in a cylindrical case 17 screwed to the valve block 14. By applying a predetermined voltage to the piezoelectric element type actuator 16, the valve element 1 is moved through a ruby ball 18 as a transmission member.
3 is driven to be pressed, whereby the opening of the valve port 8 is adjusted, and the flow rate of the gas flowing through the fluid flow path 4 is controlled.

The pressure sensor 6 comprises, for example, a strain sensor and is provided so as to face a concave portion 19 formed in the flow path 4b on the downstream side of the fluid control valve 5.

The throttle mechanism 7 is provided downstream of the flow path 4b. The configuration of the aperture mechanism 7 will be described with reference to FIG. 2. In FIG. 2A, reference numeral 20 denotes an aperture mechanism block which is provided detachably with respect to the main body block 1; A first throttle mechanism member 21 erected so as to face the terminal end of the flow path 4b facing upward, and the first throttle mechanism member 21
There is provided a diaphragm mechanism 7 including a second diaphragm mechanism member 22 which moves up and down in the upright direction in a state of being in close contact with the flow path 4c so as to face the flow path 4c.

The structure of the first diaphragm mechanism member 21 and the second diaphragm mechanism member 22 will be described in more detail. First, the first diaphragm mechanism member 21 is formed of a plate member having an appropriate thickness. In the direction, for example, three tapered holes 23, 24, and 25 having a narrowed end are formed in a straight line vertically. As shown in FIG. 2B, these holes 23 to 25 have different diameters on the downstream surface 21a of the first throttle mechanism member 21. In the illustrated example, the hole 23 is the largest, 25 is the minimum. However, the diameter of the largest diameter hole 23 is, for example, 0.5 mm (flow rate A), and the smallest diameter hole 25 is 25 mm.
Is 0.1 mm (flow rate C) and that of the middle hole 24 is 0.3 mm (flow rate B).

The second aperture mechanism member 22 is configured to slide in the up and down direction indicated by the arrow X or Y while being in close contact with the downstream surface 21a of the first aperture mechanism member 21. That is, the second aperture mechanism member 22
Is a hole 26 having a diameter larger than any of the holes 23 to 25.
22A penetrating in the thickness direction and a guided portion 22 connected to the upper portion thereof and guided by the downstream surface 21a and the guide surface 20a of the throttle mechanism block 20.
B, an output shaft 27a of an appropriate driving device 27 such as a solenoid type driving device is connected to the guided portion 22B.

In the pressure type flow control device having the above-described structure, the driving device 27 is operated to operate the second throttle mechanism member 22.
Is appropriately moved in the vertical direction, for example, as shown in FIG.
As shown in (A), the hole 26 of the second throttle mechanism member 22
Coincides with one of the plurality of holes 23 to 25 formed in the plate-shaped portion 22 </ b> A of the first aperture mechanism member 21.
As a result, only the hole 24 is opened, and the other holes 2 are opened.
3 and 25 are closed by the plate-shaped portion 22A. As a result, a flow rate B determined by the sectional area of the hole 24 is obtained.

That is, according to the above configuration, the diameter of the hole in the throttle mechanism 7 can be set alternatively, and any one of the flow rates A, B, and C set based on the sectional area of the hole can be set. Can be set to one.

In the above-mentioned pressure type flow controller, the throttle mechanism 7 is provided in the main body block 1 in which the fluid control valve 5 and the like are provided.

In the above-described first embodiment, there are three holes 23 to 25 provided in the throttle mechanism 7, and the flow rate can be set to only one of the three types of flow rates A, B, and C. However, the present invention is not limited to this, and more kinds of flow rates can be set by providing an appropriate number of holes and appropriately setting their arrangement positions. Hereinafter, this will be described as a second embodiment with reference to FIG.

As shown in FIG. 3, the first throttle mechanism member 2
In one, three holes 23 to 25 are provided so that their centers are located at the vertices of an equilateral triangle. At this time, the holes 261 to 268 provided in the second aperture mechanism member 22 are
At least one of the holes 23 to 25 needs to be larger than the largest diameter hole (in this case, the hole 25), and they are arranged as follows.

That is, the holes 261 and 262 are
The center-to-center distance is set to correspond to 25. Holes 262, 263, and 264 have a center-to-center distance set to correspond to holes 25, 23, and 24. Holes 263, 2
In the numeral 65, the center-to-center distance is set so that the holes 25 and 24 have a positional relationship. The hole 266 is provided above the hole 265, and the center distance between the holes 266 and 267 is set so that the holes 24 and 23 have a positional relationship. Further, the hole 268 is provided at a position slightly away from the hole 266 so that the other holes 261 to 267 do not match the positions of the holes 23 and 25 when the hole 268 is at a position matching the hole 24.

Reference numeral 28 denotes a horizontal line passing through the center of the hole 24, 29 denotes a horizontal line bisecting the center between the holes 261 and 262, 30 denotes a horizontal line passing through the center of the hole 264, and 31 denotes a hole. Reference numeral 32 denotes a horizontal line passing through the center of the hole 266, and reference numeral 32 denotes a horizontal line passing through the center of the hole 266.

In the throttle mechanism 7 configured as described above, the following seven types of flow rates can be set by sliding the second throttle mechanism member 22 in the directions of arrows X and Y in FIG.

The second aperture mechanism member 22 is moved in the X direction so that the lowermost hole 261 of the second aperture mechanism member 22 matches the
Only 3 is opened and holes 24 and 25 are closed. The flow rate at this time is A.

The second aperture mechanism member 22 is moved in the Y direction so that the uppermost hole 268 of the second aperture mechanism member 22 matches
Only 4 is opened and holes 23 and 25 are closed. The flow rate at this time is B.

By moving the second aperture mechanism member 22 in the Y direction and aligning the hole 267 with the hole 25, only the hole 25 is opened and the holes 23 and 24 are closed. The flow rate at this time is C.

When the second diaphragm mechanism member 22 is moved in the Y direction to make the horizontal line 32 coincide with the horizontal line 28,
The holes 267 and 266 are aligned with the holes 23 and 24, respectively, so that the holes 23 and 24 are opened and the hole 25 is closed. The flow rate at this time is A + B.

By moving the second aperture mechanism member 22,
When the horizontal line 31 is matched with the horizontal line 28, the hole 26
5,263 are aligned with holes 24,25, respectively.
25 is opened and hole 23 is closed. The flow rate at this time is B + C.

By moving the second aperture mechanism member 22,
When the horizontal line 29 matches the horizontal line 28, the hole 26
1 and 262 coincide with holes 25 and 23, respectively.
23 is opened and hole 24 is closed. The flow rate at this time is C + A.

By moving the second aperture mechanism member 22,
When the horizontal line 30 matches the horizontal line 28, the holes 26
3, 262, 264 are aligned with holes 23, 25, 24, respectively, and all holes 23, 25, 24 are opened. The flow rate at this time is A + B + C.

According to the second embodiment, a plurality of combinations (seven combinations in the illustrated example) can be easily realized, so that the flow rate can be selected in a wider range and the setting thereof can be performed very easily.

Also, in the pressure type flow control device of the second embodiment, the throttle mechanism 7 is provided in the main body block 1 in which the fluid control valve 5 and the like are provided, so that the overall configuration becomes compact. There are practical effects such as:

In each of the above embodiments, the diaphragm mechanism 7 is
Although various flow rates are realized by a so-called movable member in which a throttle mechanism member 21 and a movable second throttle mechanism member 22 are combined with the throttle mechanism member 21, a stationary type is realized by combining a throttle mechanism and an on-off valve. Can also be configured. Hereinafter, this will be described as a third embodiment with reference to FIG.

In FIG. 4, reference numerals 33 to 35 denote joint blocks formed integrally with the main body block 1 on the gas outlet side flow path 4c side of the main body block 1, and one joint block 33 is provided.
Is attached to the end of the body block 1 and the other two joint blocks 3
4 and 35 are located in a direction (vertical direction) orthogonal to the joint block 33. Numerals 36 to 38 are parallel flow paths provided so as to be connected to a downstream point of the flow path 4c. Throttle mechanisms 39 to 41 having different cross-sectional areas are formed at ends of the flow paths. I have.

Reference numerals 42 to 44 denote flow paths connected to the parallel throttle mechanisms 39 to 41, respectively.
For example, on-off valves 45 to 47 such as solenoid valves are connected to the on-off valves 45 to 44.
At point 48 downstream of 7, they merge together.

When the flow rates set by the throttle mechanisms 39 to 41 are A, B, and C, the on-off valves 45 to 48 are used.
When opening and closing are individually controlled, the following seven flow rates can be set. That is, when only the on-off valve 45 is opened, when the flow rate A is when only the on-off valve 46 is open, when flow rate B is when only the on-off valve 47 is open, and when flow rate C is when the on-off valves 45, 46 are open. When the valves 47 and 45 are open, the flow rate is C + A. When the on-off valves 45 to 47 are open, the flow rate is A + B + C.

Also in the third embodiment, a plurality (seven in the illustrated example) of combinations can be easily realized, and the flow rate selection range can be expanded accordingly, and the setting can be performed very easily.

[0043]

According to the pressure type flow control device of the present invention, a number of different flow rates can be easily set.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a configuration of a pressure type flow control device according to a first embodiment.

FIGS. 2A and 2B are diagrams illustrating an example of a configuration of a throttle mechanism in the pressure type flow control device, wherein FIG. 2A is a cross-sectional view of a main part, and FIG.

FIG. 3 is a diagram schematically showing a configuration of a diaphragm mechanism according to a second embodiment.

FIG. 4 is a diagram schematically showing a configuration of an aperture mechanism according to a third embodiment.

[Explanation of symbols]

5: fluid control valve, 7: throttle mechanism, 21: first throttle mechanism member, 22: second throttle mechanism member, 23, 24, 25,
26, 261, 262, 263, 264, 265, 26
7,268 ... holes, 39, 40, 41 ... squeezing mechanism, 45,
46, 47 ... On-off valves.

Claims (3)

[Claims] A throttle mechanism provided downstream of the fluid control valve;
In a pressure type flow control device for controlling the flow rate of gas while maintaining the pressure on the upstream side of the throttle mechanism at about twice or more the pressure on the downstream side, the throttle mechanism is configured such that a plurality of holes having different sizes are fixed. A first aperture mechanism member having a state of being arranged in the direction, and having one hole larger than the hole,
A second aperture mechanism member that moves in the arrangement direction while being in close contact with the first aperture mechanism member, and positions the holes of the second aperture mechanism member among a plurality of holes of the first aperture mechanism member. A pressure type flow control device, wherein the diameter of the hole in the throttle mechanism is set by adjusting to one of the positions. 2. A throttle mechanism is provided downstream of the fluid control valve,
In a pressure type flow rate control device for controlling a gas flow rate while maintaining the pressure on the upstream side of the throttle mechanism at about twice or more the pressure on the downstream side, the throttle mechanism has a plurality of holes having different sizes. A first aperture mechanism member and a second aperture mechanism member having a plurality of holes larger than the holes and moving while being in close contact with the first aperture mechanism member; The pressure type flow control device is characterized in that the hole diameter in the throttle mechanism is set by adjusting the position of the throttle mechanism to at least one of the plurality of holes of the first throttle mechanism member. 3. A throttle mechanism is provided downstream of the fluid control valve,
In a pressure type flow control device for controlling a gas flow rate while maintaining the pressure on the upstream side of the throttle mechanism at about twice or more the pressure on the downstream side, a plurality of the throttle mechanisms are formed so as to be parallel to each other. An on-off valve is connected in series to each of the throttle mechanisms, and the downstream side of each on-off valve is merged into one.