JPH04125706A - Pressure control valve - Google Patents

Abstract

PURPOSE:To set an output pressure to a desired value even in the case of the large change of an input pressure by determining a control element for output pressure data based on correspondence relations between plural output data sequence groups and control element sequence groups. CONSTITUTION:A diaphragm 3 is interposed between a valve housing 1 and a cap 2. A valve body 4 is energized in the cutting-off direction by a restoring spring 4b. An electrically controlled flow rate control valve 7 is inserted to an inlet passage 6 in the cap 2. It is connected to an inlet passage 5 connected to an output port 1b, and an electric flow rate control valve 10 is inserted in an inlet passage 9. A pair of needle valves are moved forward and backward to change passage stage areas of flow rate control valves 7 and 10. A pressure sensor 11 is attached to an outlet passage 8, and output data is outputted to a control computer C from the pressure sensor 11.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention controls the valve opening of a main valve by the action of the control pressure of a control pressure chamber that introduces input pressure and output pressure. This invention relates to a pressure control valve that uses a pressure control valve that converts input pressure into a predetermined output pressure.

[Prior Art] A common pressure control valve uses a diaphragm and an adjustment spring as disclosed in Japanese Patent Application Laid-Open No. 1-309150.

In this pressure control valve, the output pressure and the spring pressure oppose each other via a diaphragm, and the opening degree of the main valve is adjusted and controlled in accordance with fluctuations in the output pressure. During this time, the output pressure is controlled to converge to a predetermined pressure by the degree adjustment.

[Problems to be Solved by the Invention] However, such a pressure regulating valve has a characteristic that when the set input pressure is changed, the output pressure fluctuates. Therefore, the adjustment spring must be adjusted every time the set input pressure changes, making it impossible to perform highly accurate pressure control unrelated to changes in the set input pressure value.

An object of the present invention is to provide a pressure control valve whose output pressure hardly fluctuates even when the set input pressure is changed.

[Means for Solving the Problems] For this purpose, the present invention includes a first electrically controlled flow control valve interposed on an input pressure introduction path that introduces input pressure to the control pressure chamber, and a first electrically controlled flow control valve that introduces the output pressure to the control pressure chamber. The second electrically controlled flow rate control valve interposed on the introduction path of the a pressure to be introduced, and the first and second
A pressure control valve is configured by a control element determining means that determines a valve opening degree control element of an electrically controlled flow rate control valve, and a plurality of output pressure data ordered groups in which output pressure data are classified according to an order rule, and a valve The control element determining means selects a control element for the detected output pressure data based on a specific correspondence between a plurality of control element order groups in which the opening control elements are classified according to an order rule.

[For example, the output pressure data can be set to multiple outputs with order rules such as very low, low, somewhat low, normal, somewhat high, high, and very high. The pressure data is classified into ordered groups. The control element of an electrically controlled flow control valve is, for example, voltage, and the control element of this voltage is, for example, (very low), (low) (somewhat low), (normal), (somewhat high), (high). Control elements are classified into multiple control element order groups with order rules such as (very high). The plurality of control element order groups and the plurality of output pressure data order groups are linked by a specific correspondence relationship, and the control element determining means determines the control element for the detected output pressure data based on this specific correspondence relationship. . As a result, when the detected output pressure becomes high, the first electrically controlled flow control valve is controlled to close, and the second electrically controlled flow control valve is controlled to open. Conversely, when the detected output pressure becomes low, the second electrically controlled flow control valve is controlled to close, and the first electrically controlled flow control valve is controlled to open.

[Example] Hereinafter, an example embodying the present invention will be described based on the drawings.

A diaphragm 3 is interposed between the valve housing l and the cap 2, and a valve body 4 cuts off communication between the input port 1a and the output port lb on the valve housing l.
is connected to the diaphragm 3 via the valve stem 4a. The valve body 4 is urged in the shutoff direction by a return spring 4b.

A control pressure chamber 2a defined by a diaphragm 3 in the cap 2 and an input channel 5 connected to the input port la are connected by an introduction channel 6.
An electrically controlled first flow control valve 7 is interposed above. The output flow path 8 connected to the output capacitor) 1b and the control pressure chamber 2a are connected by an introduction flow path 9, and an electrically controlled second flow rate control valve IO is interposed on the introduction flow path 9. has been done.

The flow rate control valves 7, 10 change the passage cross-sectional areas in the orifices 7b, 1Ob by moving the needle valve bodies 7a, 10a back and forth, and the needle valve bodies 78, 10a have a support piece 7c made of a shape memory alloy.

10c. Support piece 7c.

10c has a shape memory function according to the applied voltage, and expands and contracts in the longitudinal direction according to the applied voltage value. This controls the valve opening degrees of the orifices 7b and 1Ob.

A pressure sensor 11 is attached on the output flow path 8, and output pressure data is output from the pressure sensor 11 to the control computer C. Control computer C has pressure sensor 11
Based on the detected output pressure data from the drive circuit 12.13
The voltage application to both flow rate control valves 7 and 10 is controlled via the flow rate control valves 7 and 10.

A control element determination program shown in the flowchart of FIG. 3 is input and set to the control computer C. The control elements in this case are the voltages Vf and Vh applied to the electrically driven flow rate control valves 7 and 10, which are determined by the control element determination program shown in the flowcharts of FIGS. 4(a) to 4(d).

Function g −2+ g −1+ g −I in Figure 2(a)
t g +I+g +4+ g +3 is the target output pressure P. Output pressure data order group G -31G -21G - in which the difference between the detected output pressure
1, G+++ G+z+ This is set to correspond to Gas. Output pressure data order group G -31G-21G-
11G+lI G+21 Gas is a collection of output pressures having the following differential pressure with respect to the target output pressure po.

G-3 = <large> negative differential pressure (P3- to P2-) G-2
=<normal> negative differential pressure (P2- to P+)G-, -<
Small> Negative differential pressure (Pl-~PG) G+, = <Small> Positive differential pressure (po - Pl'') G+2 = <Normal>
Positive differential pressure (P++ ~ P2+) Gas- (large) positive differential pressure (p2+ ~ P3+) However, P3- < P2- < P
l-<P. <P, + <p2+ <p3+.

Function g -3+ g -21g -1+ g +l
, g+2・g+s is output pressure data order group G-3
, G-4, G-1, G+l, G+2°G represents the accuracy of the group element X at 43. For example, output pressure data order group G
The accuracy of the output pressure P3-, which is a group element of -s, is l, and the accuracy of the output pressure P2 is 0. Also, output pressure data order group G
The accuracy of output pressure P3, which is a group element of -2, is 0, output pressure P2
The accuracy of - is l, the output pressure P, and the accuracy of - is 0.

Function f −3+ f 2+ f in FIG. 2(b)
-1+f+++f +1+f+3 is a voltage change amount data order group F-JI in which voltage change amount data regarding the first flow rate control valve 7 is classified according to a size order rule.
F-21F-I, F +l+F +2+ F +3
This setting corresponds to the following. Voltage change amount data order group F -3+ F -2+ F -1+ F +l+F
+2+F +3 is a collection of voltage changes as follows.

F-s=<large> negative change amount (ΔVfa-~ΔVf2
-) F-2 = <Normal> negative change amount IVf2-~ΔVf
l-) F-+ = <small> negative change amount (ΔVf, -~0
)F+, =<small>positive change amount (0~Δvf1+)F
+2 = <normal> positive change amount (ΔvfI+ ~ Δvf2+
) F+3 = <large> positive change amount (Δvf2+ ~ Δvf
3+) However, ΔVf3- <Δvrt-<ΔVf, -<
0 <Δvf1+<Δvf! +<Δvf2+te.

Function f-1+ f-z+ f-++ f+++
f+t+ f+2 is voltage change amount data order group F −
3,F-! l F −1+ F +l+F +l
It represents the accuracy of the group element ΔVfx at F +s.

For example, the accuracy of the voltage change amount ΔVf3-, which is a group element of the voltage change data ordered group F-s, is 1, and the voltage change amount ΔVf
The accuracy of , - is 0. Also, voltage change data order group F-
The voltage change amount ΔVf is a group element of No. 4.

The accuracy of the voltage change amount ΔVf2- is 1, and the accuracy of the voltage change amount ΔVf,- is 0.

Function h −31h−2+ h −1+ in Figure 2(c)
F1+++h+2+ h+a is the second flow control valve lo
Voltage change amount data order group H-31H-218-1 in which voltage change amount data related to is classified according to order rules of magnitude
+H+++H+21 This is set corresponding to H+s. Voltage change amount data order group H-3+ H-2+
H-1+ H+l+H+2. H+3 is a collection of voltage changes as follows.

H-3 = <large> negative change amount (Δvh, -~Δvh2
− ) H−t=<normal> negative change amount (ΔVh2−~Δ
vh, -) H-, +=<small> Negative change amount I Vhl
−~0) H++=<small> positive change amount (o~Δvh
I+) H+1=<normal> positive change amount (Δvh1+~Δ
Vh2+) H-s=<large> positive change amount (Δvh!+
~Δvh3+) However, Δvh3−<ΔVh2−<ΔVh
l-<0<ΔVhl"<ΔVh2"<ΔVh3+.

Function ri, +, h-2. h-+, h++, h+z, h+3
is the voltage change amount data ordered group H-3, H-2, H-1, H
++.

It represents the accuracy of the group element ΔVhx at H+218+3.

For example, the accuracy of the voltage change amount ΔVh3-, which is a group element of the voltage change data order group H-3, is l, and the voltage change amount ΔVh
The accuracy of 2- is 0. Also, voltage change data order group H-
The accuracy of the voltage change amount Δvh3, which is the second group element, is 0, the accuracy of the voltage change amount ΔVh,- is 1, and the accuracy of the voltage change amount Δvh1- is 0.

Control element order group F2 (j=1, 2, 3) corresponds to differential pressure data order group G+I, and control element order group F+ (i=1.2
．． 3) corresponds to the differential pressure data order group G-. Further, the control element order group H-+ corresponds to the differential pressure data order group G-+,
The control element order group H++ corresponds to the differential pressure data order group G+1. Classification of control element order group F-3°F+I, that is, voltage change amount ΔVf3-. ΔVf2ΔVf+-, ΔVf++
, ΔVfa", Δvf2+, and the classification of the control element order group H-1+ H++, namely ΔVh3Δvh2-.
Δvh, −, Δvh, +, Δvh2+.

The setting of ΔVhs+ is performed in light of experimental results.

Function 12- in Figure 3(a): lI n -2+ 1
−+, l ++.

j2 +2, 12 +3 is a differential pressure data ordered group L-3, L-2, L-1, L+l, L, which is obtained by classifying the difference ΔX between the previously detected output pressure and the currently detected output pressure using the order rules of magnitude.
+2. This is set corresponding to L+3. Differential pressure data order group L-3, L-2, L-1, L+I, L+t
, L+3 is a collection of differential pressures as follows.

L-3-(large) negative differential pressure (ΔP3-~ΔP2-)l
-2 = (normal) negative differential pressure (ΔP2- to ΔP1-) 1,
= <Small> Negative differential pressure (ΔP1-~0) L+1 = <Small> Positive differential pressure (0~ΔP1+) L+2- <Normal> Positive differential pressure (ΔP1+ ~ ΔP2+) L+3 = <Large> Positive differential pressure Differential pressure (8P2+~ΔP3+) However, ΔP3−<ΔP2−
<ΔP ΔP2+<ΔP3+.

<0<Δp + <function! -3,β-2+ 1-It (! +I+
1 +2+ j' +3 is the condition data ordered group L −
a, L -2, L -1+ L ++, L
It represents the accuracy of the group element ΔX at +2°L+s.

Function r −3+ r −2+ r in Figure 3(b)
−1+r+I+r+2, r+3 is a voltage change amount data order group R-3 in which voltage change amount data regarding the first flow rate control valve 7 in the case of detected output pressure X:p is classified using a magnitude order rule. , R-21R-1+ Ro
This setting corresponds to ll Roll R+3. Voltage change amount data order group R-31R-t+ R-1
, Roll Roll R+3 is a collection of voltage change amounts as follows.

R-3= R-2= R-1= R+1= R+2= R+3= <Large> Negative change amount <Normal> Negative change amount <Small> Negative change amount <Small> Positive change amount <Normal> Positive change amount <Large> Positive change amount (ΔEra−~ΔEr2−) (ΔEr, − ~ ΔEr, −) (ΔEr, -~0) (0~ΔEr,”) (ΔEr1+~ΔEr2”) (ΔEr, +~ΔEr3”) however, ΔErs <ΔE　r2− <ΔEr.

Ku0ku ΔEra"<ΔEr2"<ΔEr, +.

Function r 3+ r -2+ r-1+ r+l+
r+2- r+3 is the voltage change amount data order group R-
1+ R-2+ R-L+ RollR+2. It represents the accuracy of the group element ΔErx at R+3.

Function S -3+ S -2+ S in Figure 3(c)
−1+ S +I+S +21 S +3 is a voltage change amount data order group S −a that is obtained by classifying voltage change amount data regarding the second flow control valve 1o using a size order rule.
, S −2, S −+, S ++.

This is set corresponding to S+2+S+3.

Voltage change amount data order group S -L S -2+ S
−It S +l+Sya2+S+3 is a collection of voltage change amounts as follows.

5-3= 8-1= SKI" S+2= S+3= <Large> Negative change amount (Normal) Negative change amount (Small) Negative change amount (Small) Positive change amount (Normal) Positive change Amount (large) Positive change amount (ΔEs, - to ΔEs2-) (ΔEs2- to ΔEs, -) (ΔEs, - to 0) (0 to ΔEs, ") (ΔEs1+ to ΔEs2+) (ΔEs2+ to ΔEs3") However, , ΔEs3”−<ΔEs2−<ΔEs, −<0<Δ
EsI+<ΔES2”<ΔESI+.

Function S -313-215-It S (1+ S
+2・S+3 is the voltage change amount data order group S -3+
S -2+ S -It S +l+S +21
8 represents the accuracy of the group element ΔEsx at +3.

The control element order group R-1 (j=1.2.3) corresponds to the differential pressure data order group L+1, and the control element order group R+(i=1.
2.3) corresponds to the differential pressure data order group L-. Further, the control element order group S-+ corresponds to the differential pressure data order group L-1, and the control element order group S+1 corresponds to the differential pressure data order group L++. Classification of control element order group R-4°R++, that is, voltage change amount ΔEr3-+ ΔEr2ΔEr, -, ΔEr
,”, ΔE r2+, ΔEr3”, and the classification of the control element order group S −1+ S ++, i.e. ΔE s3−
ΔEsz−, ΔESI−+ ΔE SI+, ΔEs2
+.

The setting of ΔEs2+ is performed in light of experimental results.

When the detected output pressure X is input from the pressure sensor 11, the control computer C grasps the product set G3 G1+1 of the output pressure data ordered group G including the detected output pressure data X and the condition data ordered group G l+1. Then, a function g+ 9g+ corresponding to each pressure data ordered group G i + G ++1 of the product set G4 mouth G ++1 including the output pressure data X
++ Perform an operation on i using X as a variable. In the example of FIG. 2(a), g is g2, and g,+1 is g.

In the case of Xf-po, the control computer C controls the control element order groups F-I and F corresponding to the output pressure data order group G1.5+.
-+++ Function f of n -++ Inverse function f of f-1j+ll -'-+l Calculated value g+(x) for f-'-N+I+.

Calculation is performed using gH++ (X) as a variable. There are two calculation values for each variable g, (X)+g+++(X). The calculated value for the variable g+(x) is f−'−+ (g+ (x) ) ++, f−′−+
Cg+(X)]2, the coordinates (g+ (X), f-'-, + Cg+
(X)] I) point xCJ-4 and coordinates (g+ (x
), f-'-+ Cg+(x) ]2) point +2Q-1
is specified above the function f. Similarly, the variable gl++
The calculated value in the case of (X) is f−−＋＋＋o Cg＋＋＋
(X)) + + f'-+++nCgr++
(x)]2, the coordinates (gr++ (X) + f -'-+++
n Cg +++ (X)] Point t + Q -++ of I)
+n and coordinates (g+++(x)・f−−+++++
(g+++ (X) 〕2 ) point +2q−++++
+ is specified on the function f-(1+n.

The control computer C selects point +1 as shown in FIG. 2(b).
Trapezoid whose top base is the line connecting q+ + 12QI (indicated by hatching upward to the right) and point zQ +++n +12Q
The area centroid Qf (ΔVf
, ) is calculated. This area center of gravity Q[(ΔVf,
) is the voltage change amount component ΔVf of the coordinates.

and the previous applied voltage Vf is applied to the first flow rate control valve 7.

The control computer C has an inverse function f fence-1+ r-'-+
++ Along with the operation of the mouth, condition data order group GI, G4++
Function h+ of control element order group H1l HI+1 corresponding to
.

Calculation is performed regarding the inverse function h-Z + h-Z++ of h++1 using the calculated value g+ (X) + g+++ (X) as a variable. This calculated value is each variable g+ (X
)! There are two for each g+++(X). The calculated value for the variable g+ (X) is h−'+ [g+
(x)]+, hCg+ (X))2, the coordinates (g+ (x), h-'
+ Cg+ (x) ]1 point h+ql and coordinates (
g+ (x), h-Z Cg+(x) ) 2 )
The point hzzI of is the function specified above. Similarly, the calculated value for the variable gH++ (X) is h −'++−+
(g+++ (x)) + + h −'+++
Cg+++ (X)) 2, the coordinates (g+++ (X), h'++1
Cg+++ (x)) 1 point ++q+++ and coordinates (g+++ (X) + h 'IllCg++
+ (x)) 2) point b2Q+++ is the function h1+1
specified above.

The control computer C selects the point h+ as shown in FIG. 2(C).
2QI+ at the trapezoid whose top base is the line connecting Q+ + h2q+ (indicated by hatching upward to the right) and the point h+q+++++
The center of gravity of the union region of trapezoids (indicated by hatching upward to the left) whose upper base is the line connecting +. Calculate h(Δvh, ). The voltage change amount component ΔVh of the coordinates representing the area gravity center Qh (Δvh, ).

A voltage that is the sum of the voltage vh and the previously applied voltage vh is applied to the second flow rate control valve 10.

Detected output pressure X and set output pressure p. If there is a relationship with a large negative differential pressure, the voltage change amount component ΔVf.

is positive and its absolute value is large, and the voltage change amount component ΔVhf
is negative and its absolute value is large. As a result, the opening degree of the first flow rate control valve 7 changes greatly in the opening direction, and the opening degree of the second flow rate control valve 1O changes greatly in the closing direction, resulting in a large pressure rise in the control pressure chamber 2a.

When the detected output pressure small. As a result, the opening degree of the first flow control valve 7 changes slightly in the opening direction, and the opening degree of the second flow control valve 1 changes slightly.
The opening degree changes slightly from zero to the closing direction, and the pressure rise in the control pressure chamber 2a is small.

When the detected output pressure X and the set output pressure po have a large positive differential pressure relationship, the voltage change amount component ΔVf.

is negative and its absolute value is large, and the voltage change amount component ΔVh8
is positive and its absolute value is large. As a result, the opening degree of the first flow rate control valve 7 changes greatly in the opening direction, and the opening degree of the second flow rate control valve 1O changes greatly in the opening direction, resulting in a large pressure drop in the control pressure chamber 2a.

Detected output pressure X and set output pressure p. If there is a small positive differential pressure relationship between the voltage change amount component ΔVf.

is negative and its absolute value is small, and the voltage change amount component Δvhx
is positive and its absolute value is small. As a result, the opening degree of the first flow rate control valve 7 changes slightly in the closing direction, and the opening degree of the second flow rate control valve 10 changes slightly in the opening direction, so that the pressure drop in the control pressure chamber 2a is small.

In the case of x=p, the control computer C calculates the center of gravity of the area, calculates the voltage value, and applies the calculated voltage regarding the detected pressure difference ΔX between the previous time and this time in the same manner as in the case of the detected output pressure X. This control is shown in FIG. 4(C).

This is expressed as (d) and is performed in order to prevent the detected output pressure X from deviating from the set output pressure p0 when the detected output pressure X fluctuates and reaches the set output pressure po. In other words, the degree of variation in the detected output pressure X (this is expressed by the magnitude of ΔX)
The set output pressure p is large. , the detected output pressure X becomes the set output pressure p. However, by increasing the voltage change amounts ΔEf, . . . , ΔEft, the degree of deviation from the set output pressure 1)o can be suppressed. When the degree of variation in the detected output pressure X is small, the voltage change amount ΔEf,..., ΔEfA! becomes smaller.

Curve D+ in FIG. 5 represents the pressure regulation characteristics of the pressure control valve of this embodiment, and curve D2 represents the pressure regulation characteristics of the conventional pressure control valve.

In either case, the input pressure is changed in the direction of the arrow from a state where the output pressure is set pressure po = 2 kg/cri when the input pressure is 7 kg/c+d.

According to the pressure control valve of this embodiment, even if the input pressure changes greatly, the output pressure fluctuates very little. Such excellent characteristics are due to the fact that the output pressure data
++ G+t+ G+3+ L-2+ L-++L-+
, L++, Lyat+L+3, and a plurality of control element order groups F-3 in which valve opening degree control elements are classified with order rules.
F-z・F −+・F+l・F+2・F+3・
H-3゜H-2,8-1+ Re1r H+z+
H+s-+ R-3, R-21R-++ Re
ll Re21 Re3r 5-31 5-21
Control element ΔVf for detected output pressure data X based on a specific correspondence between S-11S +l+ S+2+ S+3.

Δvh, , ΔE rAw + ΔE s6. (generally called fuzzy control), and a pair of flow control valves 7.10 in which valve bodies 7a and 10a are supported by support pieces 7c and 10c made of shape memory alloy (generally, this type of valve is called a biometal valve). ).

The biometal valve 7.10 is different from a normal ON-OFF control valve in that it can maintain the valve body 7a and lOa at a desired valve opening position. This holding function is very advantageous for short-term or substantially continuous pressure control in the control pressure chamber 2a. Generally, in the case of an 0N-OFF control valve, pressure information obtained from the pressure sensor 11 can only be sampled at intervals of about 1 second due to its slow tracking ability, but with the biometal valve 7 and lO, at least about 0.02 Sampling available every second interval. Therefore, biometal valve 7
．． 10 makes it possible to control the pressure in the control pressure chamber 2a with high precision.

Based on this assumption, the output pressure data order group G −3
,G -2,G -1+ G +l+ Gya2+ G+
x+ L-3+L-2, L-+, L +l+
L+2. L +3 and control element ordered group F-3+
F −2+ F −1+ F +l+ F +21
F +318-s+H-2+ H-1+ H+ll H
+21 H+31 R-3+ R-21R-IT Ro
ll R4-21R+31 3-3+ S -218
The control element ΔVf for the detected output pressure data X based on a specific correspondence between -1+S and l+S+2+S+3.

In the fuzzy control that calculates Δvh□, ΔErAz+ΔE Sag, the control elements ΔVf , , Δvh ,
, ΔE ratΔEs□ determination program is very simple.

Conventionally, relatively complicated program control such as PID control is required for program control, and calculations that take processing time are required for each individual sampling. On the other hand, in fuzzy control, the control elements are directly calculated in a short time based on the simple correspondence between the output pressure data order group and the control element order group.

Both biometal valves? , 10 applied voltage Vf,
Vh, Er, and Es are control elements ΔVf f.

Δvh , , ΔEr4x+ ΔE SA! The pressure in the control pressure chamber 2a changes rapidly following the detected output pressure X sampled at short intervals. Moreover, each function gk + f* + hk + j'k
By appropriately setting the interval (fuzzy width) on the horizontal axis of + rk + 5k (k = -3 to 3) itself, the detected output pressure X can accurately converge to the set pressure po even if the input pressure changes significantly. do.

In the above embodiment, the control element is determined based on the difference between the detected output pressure data and the set pressure, but the control element may be determined based on the ratio between the detected output pressure and the set pressure.

The present invention is, of course, not limited to the above-mentioned embodiments. For example, when calculating the center of gravity in the above embodiments, the detected output pressure X and the differential pressure ΔX are included in the output pressure data order group and the differential pressure data order group. The amount of voltage change Δ
Vf, , Δvh, .

An embodiment in which weighting is applied to ΔErbxr ΔEs1 is also possible, and such an operation enables more accurate pressure control.

Further, the voltage change amount ΔErb based on the differential pressure ΔX in the above embodiment
t+ΔESA! The calculation may be omitted, and the pressure control may be performed only by calculating the voltage change amounts ΔVf, , Δvh, based on the detected output pressure X. In this case as well, accurate pressure control can be achieved.

Furthermore, in the present invention, a flow control valve whose opening degree can be adjusted by driving a motor may be used instead of the biometal valve.

[Effects of the Invention] As detailed above, the present invention provides a plurality of output pressure data order groups in which output pressure data is classified according to an order rule, and a plurality of output pressure data order groups in which valve opening control elements are classified according to an order rule. A control element for the detected output pressure data is determined based on a specific correspondence relationship with the control element order group, and an electric drive amount corresponding to the selected control element is applied to both electrically controlled flow control valves. As a result, even when the input pressure is greatly changed, the output pressure can be maintained at the desired set pressure with high accuracy, which is an excellent effect.

[Brief explanation of drawings]

The drawings show an embodiment embodying the present invention, and FIG. 1 is a vertical cross-sectional view of a pressure control valve, FIG. 2(a) is a graph showing the accuracy of an ordered group of detected output pressure data, b), (c
) is a graph showing the accuracy of the ordered group of control elements called voltage change amount, Figure 3 (a) is a graph showing the accuracy of the ordered group of differential pressure data, and Figures 3 (b) and (c) are the voltage change amount. Graphs showing the accuracy of the ordered group of control elements, Figure 4 (a) to (d)
) is a flowchart representing the control element determination block,
FIG. 5 is a graph showing output pressure characteristics. Flow rate control valves 7, 10, pressure sensor 11, control computer C0 as control element determining means Patent applicant: CKD Co., Ltd.

Claims (1)

[Claims] 1. The valve opening of the valve body (4) is controlled by the action of the control pressure of the control pressure chamber (2a) that introduces input pressure and output pressure, and the input pressure is controlled by this valve opening control. In the pressure control valve that converts to a predetermined output pressure, an input pressure introduction path (6) that introduces input pressure into the control pressure chamber (2a) is provided.
) interposed above the first electrically controlled flow control valve (7), and an output pressure introduction path (9) that introduces the output pressure into the control pressure chamber (2a).
) a second electrically controlled flow control valve (10) interposed on
and an output pressure detection means (11), and valves of the first and second electrically controlled flow control valves (7, 10) based on the detected output pressure data (x) obtained from the output pressure detection means (11). Opening control element (ΔVf_x, ΔVh_
x), and a plurality of output pressure data order groups (G_-_3, G_-_2, G_-_1,
G_+_1, G_+_2, G_+_3) and a plurality of control element order groups (F_-_3, F_-_2) in which valve opening degree control elements (ΔVf_x, ΔVh_x) are classified with order rules.
, F_-_1, F_+_1, F_+_2, F_+_3,
H_-_3, H_-_2, H_-_1, H_+_1, H
The control element (Δ
A pressure control valve characterized in that the control element determining means (C) is provided with a function of selecting Vf_x, ΔVh_x). 2. The pressure control valve according to claim 1, wherein the electrically controlled flow control valves (7, 10) are biometal valves.