KR20190051736A - Pneumatic servo valve using 2way proportional valve and control method thereof - Google Patents

Abstract

According to one embodiment of the present invention, a pneumatic servo valve using a two-way proportional valve comprises: a valve body having an input side insertion hole in which an inflow pipe is inserted and an output side insertion hole in which a supply pipe is inserted are respectively recessed on both ends, and having a main flow path formed therein for providing a path so that the fluid of the inflow pipe flows to the supply pipe by connecting the input side insertion hole and the output side insertion hole; a pressure sensing unit connected to the main flow path to transmit a measured pressure measuring an internal pressure of the main flow path; an opening and closing unit connected to the main flow path and capable of opening and closing the main flow path; and, a control unit connected to the pressure sensing unit and the opening and closing unit and transmitting to the opening and closing unit a control signal including information on an opening rate generated by comparing the measured pressure transmitted from the pressure sensing unit with a target pressure.

Description

TECHNICAL FIELD [0001] The present invention relates to a pneumatic servo valve using a 2-way proportional valve,

The present invention relates to a pneumatic servo valve and a control method thereof, and more particularly to a pneumatic servo valve and a control method thereof that prevent an overshoot in which a control amount rises above a target value, To a pneumatic servo valve using a direction proportional valve and a control method thereof.

In general, a servo valve is a valve that controls the flow rate or pressure using a function of an input signal. These servo valves are widely used in various industrial fields such as various hydraulic systems for automobiles, automatic transmissions for automobiles, and construction machines.

In particular, a mushroom-shaped poppet valve with a valve cap and a valve stem is used for the pneumatic servo valve.

However, such a pneumatic servo valve has a limitation in controlling minute pressure or flow rate, so that there is a problem that fluid flow amount and flow pressure can not be precisely controlled.

In addition, there is a problem in that an overshoot occurs in which the control amount exceeds the target value and the output pressure of the external tank can not be precisely controlled.

Korean Patent Registration No. 10-0285928 (Mar. 15, 2001)

The present invention provides a pneumatic servo valve using a bi-directional proportional valve that can precisely control an output pressure of an external tank by preventing an overshoot in which a control amount exceeds a target value, and a control method thereof .

Another problem to be solved by the present invention is to provide a pneumatic servo valve using a bi-directional proportional valve capable of precisely controlling a fluid flow amount and a flow pressure, and a control method thereof.

Further objects to be solved by the present invention will become more apparent from the following detailed description and drawings.

According to an embodiment of the present invention, the pneumatic servo valve using the bi-directional proportional valve is characterized in that the input side inlet port into which the inlet pipe is inserted and the output side inlet port into which the supply pipe is inserted are formed at both ends, respectively, A valve body having a main passage formed therein for connecting the inlet pipe to the supply pipe and providing a path for the fluid to flow into the supply pipe; A pressure sensing unit connected to the main flow path to transmit a measurement pressure measuring an internal pressure of the main flow path; An opening / closing unit connected to the main flow path and capable of opening and closing the main flow path; And a control unit connected to the pressure sensing unit and the opening and closing unit and transmitting a control signal including opening and closing amount information generated by comparing the measured pressure transmitted from the pressure sensing unit with a target pressure to the opening and closing unit .

The control signal may include a first control signal and a second control signal, wherein the opening and closing unit may include a first proportional valve and a second proportional valve, each of which is operated by the first control signal and the second control signal, respectively have.

Wherein the main flow path includes a first main flow path connected to the input side inlet and opened and closed by the first proportional valve; A second main passage communicating with the first main passage when the first main passage is opened; A third main flow path having one end connected to the second main flow path and the other end connected to the output side insertion port; A fourth main flow path whose one end is connected to the second proportional valve and opened and closed and the other end is connected to the third main flow path; And a fifth main passage communicated with the fourth main passage when one end is connected to the second proportional valve and the fourth main passage is opened.

The pressure sensing unit may include: a pressure sensing channel having one end connected to the third main channel; And a pressure sensor connected to the other end of the pressure sensing flow path to measure the internal pressure of the pressure sensing flow path.

The valve body may be formed with a buffer passage having one end communicating with the third main passage and the other end communicating with the outside.

The diameter of the buffer passage may be less than 50% of the diameter of the third main passage. And preferably 20% to 30%.

According to another embodiment of the present invention, there is provided a method of controlling a pneumatic servo valve using a bi-directional proportional valve, comprising the steps of: measuring pressure inside the main flow path by the pressure sensing unit; The control unit comparing the measured pressure with a target pressure to transmit a control signal including information on opening / closing amount; And a step of opening and closing the main flow path by receiving the control signal from the closure unit.

The control signal may include a first control signal and a second control signal, wherein the opening and closing unit may include a first proportional valve and a second proportional valve, each of which is operated by the first control signal and the second control signal, respectively have.

Advantages of the pneumatic servo valve and the control method thereof using the two-way proportional valve according to the present invention are as follows.

First, there is an advantage that the output pressure of the external tank can be precisely controlled by preventing an overshoot in which the control amount exceeds the target value.

Second, there is an advantage that the flow amount and flow pressure of the fluid can be precisely controlled.

1 is a use state diagram of a pneumatic servo valve using a two-way proportional valve according to an embodiment of the present invention.
2 is a sectional view of a pneumatic servo valve using a bi-directional proportional valve according to an embodiment of the present invention.
3 is a control block diagram of a pneumatic servo valve using a two-way proportional valve according to an embodiment of the present invention.
4 to 6 are views showing the operation of the pneumatic servo valve using the bi-directional proportional valve of Fig.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The embodiments of the present invention can be modified in various forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments are provided to explain the present invention to a person having ordinary skill in the art to which the present invention belongs. Accordingly, the shape of each element shown in the drawings may be exaggerated to emphasize a clearer description.

1 is a use state diagram of a pneumatic servo valve using a two-way proportional valve according to an embodiment of the present invention. 1, a pneumatic servo valve 1 using a bi-directional proportional valve according to the present embodiment is configured to supply a fluid to an external tank 7 or to discharge a fluid from an external tank 7, The output pressure can be adjusted.

The pneumatic servo valve 1 is installed between the inflow pipe 3 and the supply pipe 5 and connects the inflow pipe 3 and the supply pipe 5. The pneumatic servo valve 1 can increase the output pressure of the external tank 7 by supplying the fluid introduced from the inflow pipe 3 to the supply pipe 5. [ The pneumatic servo valve 1 can lower the output pressure of the outer tank 7 by exhausting the fluid from the supply pipe 5 connected to the outer tank 7. [

FIG. 2 is a sectional view of a pneumatic servo valve using a 2-way proportional valve according to an embodiment of the present invention, and FIG. 3 is a control block diagram of a pneumatic servo valve using a 2-way proportional valve according to an embodiment of the present invention. 2 and 3, the pneumatic servo valve 1 using the bi-directional proportional valve according to the present embodiment controls the pressure and the flow rate due to the movement of the fluid when the fluid passes through the valve body 9, An opening / closing unit 30, a pressure sensing unit 40, and a control unit 50. [

The valve body 9 is formed at one end with an input side insertion portion 2 into which an end portion of the inlet pipe 3 is inserted and at the other end with an output side inlet port 4 into which an end portion of the supply pipe 5 is inserted . A main flow path 10 is formed in the valve body 9. The fluid flowing through the inflow pipe 3 moves to the supply pipe 5 through the main flow path 10 of the valve body 9.

The main flow path 10 connects the input side inlet 2 and the output side inlet 4 and guides the fluid flowing through the inlet pipe 3 to the supply pipe 5. The main channel 10 includes a first main channel 11, a second main channel 12, a third main channel 13, a fourth main channel 14 and a fifth main channel 15.

One end of the first main passage 11 is connected to the input side inlet 2 and the other end is connected to the first proportional valve 31. The first main flow passage 11 is opened and closed by the first proportional valve 31. Specifically, the other end of the first main passage 11 is connected to the lower portion of the first orifice 31a to communicate with the first orifice 31a, and the upper end of the first orifice 31a is opened. The opened upper end of the first orifice 31a can be opened and closed by the lifting movement of the first stopper 31b connected to the lower end of the first spider ring 31c. The first stopper 31b opens the first orifice 31a by the magnetic force of an electromagnet (not shown) installed in the upper space of the first proportional valve 31 and, in a state where the magnetic force of the electromagnet is blocked, The first orifice 31a can be closed by the elastic restoring force of the ring 31c.

One end of the second main flow path 12 is connected to the second proportional valve 32 and the other end is connected to the third main flow path 13. When the first proportional valve 31 is operated by the first control signal of the control unit 50 and the first main flow passage 11 is opened by the first proportional valve 31, ) Communicates with the first main flow passage (11).

One end of the third main flow path 13 is connected to the other end of the second main flow path 12 and the other end is connected to the output side insertion port 4. [

One end of the fourth flow path (14) is connected to the second proportional control valve (32) and the other end is connected to the third main flow path (13).

The fifth main passage 15 has one end connected to the second proportional valve 32 and the other end connected to the outside of the valve body 9. The second proportional valve 32 is operated by the second control signal of the control unit 50 and when the fourth main flow passage 14 is opened by the first proportional valve 32, 15 communicate with the fourth main flow path 14. Specifically, one end of the fifth main passage 11 is connected to the lower portion of the second orifice 32a to communicate with the second orifice 32a, and the upper end of the second orifice 32a is opened. The second stopper 32b opens the second orifice 32a by the magnetic force of an electromagnet (not shown) installed in the upper space of the second proportional valve 32, The second orifice 32a can be closed by the elastic restoring force of the ring 32c.

The first stopper 31b and the second stopper 32b may be made of a material attached to a magnet such as iron.

The first spider ring 31c and the second spider ring 32c are in the form of leaf springs made of metal and have a fast recovery speed in the original phase and hardly change in the elastic modulus and can be used semi-permanently for a long life.

When the first proportional valve 31 and the second proportional valve 32 are opened by the control signal of the control unit 50, the fluid flowing through the inflow pipe 3 flows through the first main flow passage 11, The main flow path 12, the third main flow path 13, the fourth main flow path 14 and the fifth main flow path 15 in this order.

When the first proportional valve 31 is opened by the control signal of the control unit 50 and the second proportional valve 32 is not opened, the fluid flowing through the inflow pipe 3 flows into the first main flow passage 11 A part of the fluid introduced into the third main flow path 13 flows into the supply piping 5 through the second main flow path 12 and part of the fluid flowing into the third main flow path 13 flows into the fourth main flow path 13, Thereby filling the interior of the main flow path 14. At this time, since the fourth main passage 14 and the fifth main passage 15 are not communicated with each other, no fluid flows into the fifth main passage 15. [ At this time, since the fluid is exhausted to the outside through the buffer flow path 20 communicating with the third main flow path 13, the function of buffering the pressure of the fluid supplied to the external tank 7 is buffered.

When the second proportional valve 32 is opened by the control signal of the control unit 50 and the first proportional valve 31 is not opened, the fluid flowing through the supply pipe 5 flows into the third main flow passage 13 Is exhausted to the outside through the fifth main passage (15) via the fourth main passage (14). Therefore, the output pressure of the external tank 7 becomes low. At this time, since the second main flow path 12 and the first main flow path 11 do not communicate with each other, the fluid does not flow into the first main flow path 11.

The opening / closing unit 30 is installed on the outer surface of the valve body 9 and opens / closes the main flow path 10 by a control signal of the control unit 50. The opening and closing unit 30 includes a first proportional valve 31 and a second proportional valve 32.

The first proportional valve 31 is installed on the side closer to the inflow pipe 3 and the second proportional valve 32 is provided on the side close to the supply pipe 5. As can be seen from the name of the first proportional valve 31 and the second proportional valve 32, the opening and closing unit 30 according to the present invention may be constituted by a proportional valve.

The proportional control valve is a valve that is controlled by the pressure, temperature, flow rate, etc. of the primary and secondary, and controls the speed or opening degree of operation according to the input operation value (called pid value) The diaphragm inside the diaphragm adjusts the amount of air and sends it back to the controller called positioner to determine the degree of opening of the valve.

The pressure sensing unit 40 is connected to the third main passage 13 and measures the internal pressure of the third main passage 13. The pressure sensing unit 40 includes a pressure sensing sensor 41 and a pressure sensing passage 42.

One end of the pressure sensing flow path 42 communicates with the third main flow path 13, and the other end is connected to the pressure sensing sensor 41.

The pressure sensing sensor 41 is electrically connected to the control unit 50 and transmits to the control unit 50 a measured pressure that measures the internal pressure of the pressure sensing flow path 42.

The control unit 50 is electrically connected to the pressure sensing unit 40 and the opening and closing unit 30 and compares opening and closing amount information calculated by comparing the measured pressure transmitted from the pressure sensing unit 40 with a predetermined target pressure, Unit 30 as shown in FIG. The first proportional valve 31 and the second proportional valve 32 open and close the first main flow passage 11 and the fourth main flow passage 14 in accordance with the opening / closing amount information, respectively.

The control unit 50 may also be connected to the user terminal 60 and may download the time information required to reach the target pressure from the user terminal 60 and transmit the information to the first and second opening / Information can be transferred to the first proportional valve 31 and the second proportional valve 32.

On the other hand, the buffer passage 20 serves to buffer the actual output pressure of the external tank 7 from being higher than the target pressure due to the velocity of the fluid when the fluid is supplied to the external tank 7, One end of the buffer passage 20 communicates with the third main passage 13, and the other end communicates with the outside. Therefore, the fluid in the third main flow path 13 is exhausted to the outside through the buffer flow path 20, so that the internal pressure of the third main flow path 13 is lowered to some extent. The diameter of the buffer passage 20 may be 50% or less of the diameter of the first orifice 31a of the first proportional valve 31. And more preferably 20 to 30%. For example, if the diameter of the first orifice 31a is 1 [mm], the diameters of the buffer passage 20 may be 0.05, 0.1, 0.2, 0.3 and 0.4 [mm].

4 to 6 are views showing the operation of the pneumatic servo valve using the bi-directional proportional valve of Fig. Hereinafter, the operation of the pneumatic servo valve using the two-way proportional valve according to the present embodiment will be described step by step with reference to Figs.

4, when the first proportional valve 31 and the second proportional valve 32 are shut off, the fluid flowing through the inflow pipe 3 moves to the first main flow passage 11. At this time, since the first main flow passage 11 and the second main flow passage 12 are not communicated with each other, the fluid does not flow into the second main flow passage 12.

Next, as shown in Fig. 5, when the first proportional valve 31 is opened by the control signal of the control unit 50 and the second proportional valve 32 is not opened, the fluid flowing through the inflow pipe 3 Flows into the third main flow path 13 through the first main flow path 11 and the second main flow path 12 and moves into the supply piping 5 and flows into the third main flow path 13 A portion of the fluid flowing into the fourth main flow path 14 is filled. Therefore, the output pressure of the external tank 7 becomes high. At this time, since the fourth main passage 14 and the fifth main passage 15 are not communicated with each other, no fluid flows into the fifth main passage 15. [

Next, when the second proportional valve 32 is opened and the first proportional valve 31 is not opened by the control signal of the control unit 50 as shown in Fig. 6, the fluid flowing through the supply pipe 5 Is discharged to the outside through the fifth main passage (15) via the third main passage (13) and the fourth main passage (14). Therefore, the output pressure of the external tank 7 becomes low. At this time, since the second main flow path 12 and the first main flow path 11 do not communicate with each other, the fluid does not flow into the first main flow path 11.

As a result, the pneumatic servo valve using the bi-directional proportional valve according to the present invention can prevent the overshoot where the control amount exceeds the target value, thereby precisely controlling the output pressure of the external tank, The flow pressure can be precisely controlled.

Although the present invention has been described in detail by way of preferred embodiments thereof, other forms of embodiment are possible. Therefore, the technical idea and scope of the claims set forth below are not limited to the preferred embodiments.

1: Pneumatic servo valve with 2-way proportional valve 2: Input port
3: inflow pipe 4: output side inlet
5: Supply piping 7: External tank
9: valve body 10: main flow path
11: first main flow path 12: second main flow path
13: third main flow channel 14: fourth main flow channel
15: fifth main flow path 20: buffer flow path
30: opening and closing unit 31: first proportional valve
32: second proportional valve 40: pressure sensing unit
41: pressure sensing channel 42: pressure sensing sensor
50: control unit 60:

Claims (8)

A main inlet port through which the inlet pipe is inserted and an outlet port through which the supply pipe is inserted are formed at both ends of the inlet port and a port for connecting the inlet port and the outlet port to provide a path for moving the fluid of the inlet pipe to the supply pipe, A valve body having a flow path formed therein;
A pressure sensing unit connected to the main flow path to transmit a measurement pressure measuring an internal pressure of the main flow path;
An opening / closing unit connected to the main flow path and capable of opening and closing the main flow path; And
And a control unit connected to the pressure sensing unit and the opening and closing unit and transmitting a control signal including opening and closing amount information generated by comparing the measured pressure transmitted from the pressure sensing unit with a target pressure to the opening and closing unit Pneumatic servo valve with two-way proportional valve. The method according to claim 1,
Wherein the control signal comprises a first control signal and a second control signal,
Wherein the opening and closing unit includes a first proportional valve and a second proportional valve that are respectively operated by the first control signal and the second control signal,
The main flow path,
A first main flow path connected to the input side inlet and opened / closed by the first proportional valve;
A second main passage communicating with the first main passage when the first main passage is opened;
A third main flow path having one end connected to the second main flow path and the other end connected to the output side insertion port;
A fourth main flow passage whose one end is connected to the second proportional valve to open and close and the other end to the third main flow passage;
And a fifth main flow passage, one end of which is connected to the second proportional valve and is in communication with the fourth main flow passage when the fourth main flow passage is opened. The method of claim 2,
The pressure sensing unit includes:
A pressure sensing flow path whose one end is connected to the third main flow path; And
And a pressure sensor connected to the other end of the pressure sensing flow path to measure an internal pressure of the pressure sensing flow path. The method of claim 2,
Wherein the valve body has a buffer flow path having one end communicating with the third main flow path and the other end communicating with the outside. The method of claim 4,
Wherein the diameter of the buffer passage is less than 50% of the diameter of the third main passage. The method of claim 5,
Wherein the diameter of the buffer passage is 20% to 30% of the diameter of the third main passage. A method for controlling a pneumatic servo valve using a two-way proportional valve according to claim 1,
The internal pressure of the main flow path is measured by the pressure sensing unit, and the measurement pressure is transmitted;
The control unit comparing the measured pressure with a target pressure to transmit a control signal including information on opening / closing amount; And
And a step of opening and closing the main flow path by receiving the control signal from the closure unit. The method of claim 7,
Wherein the control signal comprises a first control signal and a second control signal,
Wherein the opening / closing unit includes a first proportional valve and a second proportional valve that are respectively operated by the first control signal and the second control signal.

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