JP2000347745A - Control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control valve which secures the stability of zero point without performing closed loop control corresponding to the fluctuation of supply pressure nor making the supply pressure constant. SOLUTION: The proportional constant of the change of signal pressure at zero point with respect to the supply pressure of nozzle flappers 45 and 60 and the proportional constant of the change of signal pressure at zero point with respect to the supply pressure of a valve main body are set almost in reverse relation to each other. The characteristics of the flappers 45 and 60 and the characteristics of the valve main body are also adjusted so that the influence of change of supply pressure can be almost offset when combined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regulating valve, and more particularly to a regulating valve for extracting an output pressure corresponding to an externally supplied electric signal.

[0002]

2. Description of the Related Art For example, a gas pressure booster proposed in Japanese Patent Publication No. Hei 7-107401 has an auxiliary plate connected to a movable plate by a connecting rod on an outer peripheral side instead of a center side, and this auxiliary plate is provided. A seal ring having an effective area substantially equal to a diaphragm for applying supply pressure is interposed between the auxiliary plate and the passage of the casing between the auxiliary plate and the passage of the casing. And cut off. According to such a booster, the output pressure is not affected by the supply pressure, the hysteresis caused by friction can be prevented, and the size and the capacity are increased.

[0003]

However, such a conventional regulating valve comprising a booster has a problem that if the supply pressure is also used as the pilot pressure, the signal pressure at the zero point is affected by the fluctuation of the supply pressure. In order to solve such a drawback, closed loop control of the supply pressure is performed, and when the output pressure fluctuates in conjunction with the supply pressure, the control valve performs a control operation to cancel the fluctuation. And take other measures. Another method is to keep the supply pressure constant.

However, in order to perform closed loop control,
In addition to requiring a sensor to detect supply pressure,
A control element for performing control in accordance with the detection output of this sensor is required, and there is a disadvantage that the configuration is complicated. In order to keep the supply pressure constant, a special adjustment mechanism is required, and in this case also, the configuration is complicated.

The present invention has been made in view of such a problem, and does not perform closed loop control by a sensor, or does not maintain a constant supply pressure, and furthermore, does not deal with fluctuations in the supply pressure. Output pressure, especially its 0
It is an object of the present invention to provide a regulating valve that operates without changing the point.

[0006]

According to one aspect of the present invention, there is provided an adjustment valve for extracting an output corresponding to an electric signal supplied from the outside, wherein an electromagnetic valve in which a signal pressure at a zero point increases as a supply pressure increases. Nozzle flapper and 0 when supply pressure increases
And a valve body having a reduced output pressure at a point, wherein the back pressure of the nozzle of the electromagnetic nozzle flapper is used as a signal pressure of the valve body. Here, the proportionality constant of the change of the signal pressure at the point 0 with respect to the supply pressure of the electromagnetic nozzle flapper and 0 with respect to the supply pressure of the valve body
The characteristics of the electromagnetic nozzle flapper and the valve body are such that the proportional constants of the changes in the output pressure at the points are substantially opposite to each other, and the effects of the changes in the supply pressure are almost offset when combined. The characteristic may be adjusted.

Here, the flapper of the electromagnetic nozzle flapper may be moved in the axial direction by the coil of the linear motor to adjust the gap between the flapper and the tip of the nozzle. Further, the supply pressure may be applied to the nozzles of the electromagnetic nozzle flapper as an operating pressure, and the back pressure of the nozzles may be extracted as a signal pressure.

The valve body has an input diaphragm for receiving a signal pressure and an output diaphragm for receiving an output pressure, and the input diaphragm and the output diaphragm are arranged so as to press each other via a rigid body for transmitting a force. Further, a balance diaphragm receiving a supply pressure may be provided, and the balance diaphragm may press the output diaphragm toward the input diaphragm through a pressure plate.
Further, the effective area of the balance diaphragm may be sufficiently smaller than the effective areas of the input diaphragm and the output diaphragm. Further, a poppet may be provided and connected to the pressure plate via a rod slidably supported in a guide hole in the body. Further, one of the pressure plate and the poppet connected to each other by a rod may be pressed by a spring so as to cancel the weight of both.

[0009]

FIG. 1 shows an entire configuration of a regulating valve according to an embodiment of the present invention. The regulating valve has a body 10 and a lower portion of the body 10 is provided. A supply port 11 is formed on the left side of the portion, and an output port 12 is formed on the right side thereof.

The body 10 has a first recess 16 on its upper side, and an input diaphragm 17 so as to close the upper opening of the recess 16. The input diaphragm 17 is adapted to be received by a pressure plate 18 disposed below the input diaphragm 17. The pressure plate 18 has a center boss 19 having a relatively large diameter so as to protrude downward. The center boss 19 presses a substantially central portion of the output diaphragm 20. The space between the input diaphragm 17 and the output diaphragm 20 in the first recess 16 is communicated with the outside by the small hole 21,
It is maintained at a pressure equal to the atmospheric pressure.

A second recess 22 is provided below the first recess 16. The output diaphragm 20 is arranged so as to block the first recess 16 and the second recess 22 from each other. The receiving plate 2 is provided in the second recess 22 so as to receive such an output diaphragm 20.
Three are arranged. The receiving plate 23 is urged upward by a spring 24.

A pressure plate 25 is provided in the second recess 22 so as to contact the lower surface of the receiving plate 23. The pressure plate 25 is connected to a lower poppet 27 via a rod 26. Here, the poppet 27 is disposed in the third recess 28. The rod 26 is slidably supported on the body 10 by a through hole 29. An O-ring 30 is attached to the upper surface of the poppet 27, and the O-ring 30 is pressed against the upper surface inside the recess 28.

A projection 35 is provided below the pressure plate 25, and the projection 35 is connected to a balance diaphragm 36.
Is pressed. The balance diaphragm 36 receives a pressing force of a cancel spring 38 via a spring receiver 37 disposed below the balance diaphragm 36.

Next, the mechanism of the nozzle flapper disposed above the valve body composed of the body 10 having such a configuration will be described. The nozzle 45 has a center hole 46, and a portion on the base end side of the nozzle 45 is configured as a holding portion 47, and the concave portion 4 provided in the upper body 48 is provided.
9 is supported.

The nozzle 45 has a horizontal hole 50 communicating with the center hole 46, and the horizontal hole 50 communicates with a communication groove 51 formed on the outer peripheral surface of the holding portion 47. A port 52 is formed in the body 48 so as to communicate with the communication groove 51, and the port 52 communicates with the space inside the recess 16 above the input diaphragm 17. The port 52 is connected to the supply port 11 via the throttle passage 53 and the communication passage 54.

Next, the flapper 60 arranged to face the tip of the nozzle 45 will be described. The flapper 60 is made of, for example, a thin plate of phosphor bronze, and an opening 61 is formed in an outer peripheral portion thereof so as to communicate the front and back sides. Further, the periphery of such a flapper 60 is stretched by a casing 62.

A yoke 63 is provided in the casing 62, and a magnet 64 is provided inside the yoke 63.
And a center core 65 are respectively attached. Further, a coil 66 is arranged on the outer peripheral side of the center core 65 and in the gap between the inner peripheral side of the yoke 63. The coil 66 is attached to the bobbin 67. The coil 66 is connected to the flapper 60 via a bobbin 67. A small hole 68 is formed so as to penetrate the yoke 63 and the casing 62, so that the pressure inside the casing 62 is maintained at the atmospheric pressure.

Next, an outline of the operation of such a regulating valve will be described. A signal current is applied to the coil 66 in the casing 62. Since the coil 66 is disposed in the air gap of the magnetic circuit formed by the magnet 64, the signal current applied to the coil 66 causes the coil 66 to move in the axial direction. That is, here, a linear motor is constituted by the coil 66, the magnet 64, the yoke 63, and the center core 65, and the flapper 60 receives a force in the left and right directions in FIG. 1 by such a linear motor. Therefore, the flapper 60 is displaced with respect to the tip of the nozzle 45 by such a force.

The supply pressure applied through the supply port 11 is applied as an operating pressure to the nozzle 45 through the communication passage 54 and the throttle passage 53. Such an operating pressure is reduced according to the amount of outflow flowing through the gap between the flapper 60 and the nozzle 45, and the reduced pressure is applied to the signal pressure through the center hole 46, the lateral hole 50, the communication groove 51, and the port 52. And this signal pressure acts on the upper surface of the input diaphragm 17.

On the other hand, since the lower recess 28 communicates with the output port 12, the inside of the recess 28 is maintained at the output pressure. Since such an output pressure is applied to the concave portion 22 through the through hole 29 of the body 10, the concave portion 2
The pressure in 2 becomes equal to the output pressure, and the lower surface of the output diaphragm 20 receives the output pressure.

On the other hand, since the supply pressure from the supply port 11 is applied to the center hole 40 formed in the center of the body 10 so as to penetrate vertically, the supply pressure is applied to the lower surface of the balance diaphragm 36. Pressure is applied. Further, the elastic restoring force of the cancel spring 38 is applied to the lower surface of the balance diaphragm 36 via the spring receiver 37.
Further, the supply pressure applied to the center hole 40 is applied to a region on the upper surface of the poppet 27 and closer to the center than the O-ring 30.

When the signal current flowing through the coil 66 is increased, the flapper 60 is pressed to the left in FIG. 1 and approaches the tip of the nozzle 45, thereby increasing the back pressure of the nozzle 45, that is, the signal pressure. I do. Therefore, the diaphragm 17 to which the signal pressure is applied to the upper surface receives a larger force downward and moves downward. Then, the force of the input diaphragm 17 is applied to the pressure plate 25 via the pressure plate 18, the center boss 19, the output diaphragm 20, and the receiving plate 23. Therefore, the pressure plate 25 moves downward.

Since the pressure plate 25 is connected to the poppet 27 via the rod 26, when the pressure plate 25 moves downward, the poppet 27 also moves downward. Therefore, the O-ring 30 provided on the upper surface of the poppet 27 is
8 away from the upper surface. Therefore, the supply pressure from the supply port 11 flows from the center hole 40 to the third concave portion 28, and the output pressure taken out through the output port 12 increases.

The output pressure is applied to the lower surface of the output diaphragm 20 within the recess 22. As the output pressure increases, the force of pushing the output diaphragm 20 upward gradually increases, and then the output pressure is lowered by the input diaphragm 17. When the amount of increase in the force is canceled, the balance of the force is reached again, and the pressure plate 25 and the poppet 27 move upward as shown in FIG. , Shut off the supply pressure. This will reach a new equilibrium.

When the signal current applied to the coil 66 is reduced, the force of the coil 66 pressing the flapper 60 to the left decreases, and the balance between the flapper 60 itself and the elastic restoring force reduces the nozzle 45 and Flapper 60
The gap between them increases. Therefore, in this case, the nozzle 4
5 will be reduced.

When the back pressure of the nozzle 45, that is, the signal pressure decreases, the signal pressure applied to the upper surface of the input diaphragm 17 decreases, so that the output diaphragm 2 receives the output pressure.
The input diaphragm 17 is moved upward by the zero pressing force. Therefore, the pressure plate 18 and the center boss 1
9 also moves upward by the elastic restoring force of the spring 24.

Then, the tip of the center boss 19 is separated from the output diaphragm 20. Therefore, the output diaphragm 2
0 and the center hole 4 formed through the receiving plate 23
1 will open. Therefore, the output pressure of the space in the second recess 22 through the center hole 41 is reduced by the first recess 16.
And escapes to the outside of the body 10 through the small holes 21. This gradually reduces the output pressure. When the force due to the output pressure reaches a state where the force due to the signal pressure balances, the center boss 19 again contacts the upper surface of the output diaphragm 20, closes the center hole 41, and reaches a new equilibrium state of the force.

Next, in the case of such an adjusting valve, especially the nozzle 45
The influence of the supply pressure on the signal pressure taken out as the back pressure of the vehicle will be described using mathematical expressions. Here, the symbols used in the mathematical expressions are transcribed as follows.

[0029] Q _1: flow rate Q ₂ to which passes through the orifice 53: Flow pass between the nozzle 45 and the flapper 60 P _s: supply pressure P _i: signal pressure (input pressure) P _a: atmospheric C _1: Orifice Resistance of 53 C ₂ : Resistance of flapper 60 K ₁ : Proportional constant K _s : Proportional constant (spring constant of flapper 60) s: Inner diameter of central hole 46 of nozzle 45 _Ko : Constant First, operating pressure is applied to nozzle 45. flow rate to Q ₁ supply pressure P _{s is, Q 1 = C 1 · P} s (1) the flow rate Q ₂ to which flows out from the tip of the flapper 60 is opposed to the nozzle _{45, Q 2 = C 2 · (} P i - P _a ) ^1/2 (2) where C ₂ = K ₁ · x (3) where x indicates a gap between the tip of the nozzle 45 and the flapper 60. When the gap is x, the balance of the force in the flapper 60 is as follows.

K _s · x = (P _i −P _a ) · s (4) Here, if Q ₁ = Q ₂ and P _a = 0, the following equation is established.

C ₁ · P _s = C ₂ · P _i ^1/2 = K ₁ · x · P _i ^1/2 = K ₁ · s · P _i ^3/2 / K
_s (5) P _i = {(C ₁ · K _s · P _s ) / (K ₁ · s)} ^2/3 (6) Here, _Ko is set as follows.

{(C ₁ · K _s ) / (K ₁ · s)} ^3/2 = K _o (7) Using this equation, equation (6) is expressed as follows.

P _i = K _o · P _s ^2/3 (8) As is apparent from the above equation, the signal pressure P _i is equal to the supply pressure P _s
Function. Coil 6 supply pressure P _s as a parameter
Relationship between the signal pressure P _i obtained as a back pressure of the signal current and the nozzle 45 to flow to 6 is illustrated by Figure 3. As is apparent from this equation, the signal pressure P _i will increase in accordance with supply pressure P _s is increased.

[0034] Attention is now directed to the signal pressure P _i of 0 points. FIG. 4 shows a change in the signal pressure P _i when a signal current corresponding to the zero point of the regulating valve flows through the coil 66. That is, 0
The signal pressure P _i of the point will depend on the supply pressure P _s, it tends to increase the supply pressure P _s is increased is shown by Figure 4.

[0035] If now supply pressure P _s is set the signal pressure P _i when the 5 kgf / cm ² so as to 0.2 kgf / cm ^2, becomes K _o = 0.068 K _o of (7) . Therefore, equation (8) is represented by the following equation.

[0036] ^{_{P i = 0.068P s 2/3 (9}} ) When representing this equation (9) graphically becomes as shown in FIG. 5, the signal pressure of zero point of the control valve to changes in the signal pressure P _s changes in P _i is indicated as a change in specific numerical values.

[0037] Next, consider the equation for the change in the output pressure P _o by the supply pressure P _s of the valve body for adjusting operation in response to the signal pressure P _i. Here, the symbols are set as follows.

P _o : Output pressure A ₁ : Effective area of input diaphragm 17 A ₂ : Effective area of output diaphragm 20 A ₃ : Effective area of balance diaphragm 36 A ₄ : Effective area of poppet 30 (inside of O-ring 30) Area) The formula of the balance of the force of the valve body of the regulating valve shown in FIG. 1 is as follows.

P _i · A ₁ = P _o · A ₂ + P _s · (A ₃ -A ₄ ) (10) Here, P _i · A ₁ on the left side is a downward direction that the input diaphragm 17 receives due to the signal pressure P _i . Power. The first term on the right side is the upward force experienced by the output diaphragm 20 by the output pressure P _o. The second term of the right side shows values balance diaphragm 30 is the poppet 27 from the upward force experienced by the supply pressure P _s minus the downward force experienced by the supply pressure P _s.

Here, _assuming that A ₃ −A ₄ = ＰA, P _i · A ₁ = P _o · A ₂ + ＰA · P _s (11) Therefore, P _o = P _i · (A ₁ / A ₂ ) −P _s · (△ A / A ₂ ) (12) By substituting equation (8) into equation (12), P _o = K _o · (A ₁ / A ₂ ) · P _s ^2/3 − (△ A / A ₂ ) P _s (13) As is apparent from the above equation (13), the output pressure _Po is a function of the supply pressure P _s . Change of the output pressure P _o when the supply pressure P _s was varied signal pressure P _i as a parameter 6
It becomes as shown in. Here the relationship between the output pressure P _o and the supply pressure P _s in the zero point of the regulating valve is shown in FIG. As it is apparent from the equation of FIG. 7, the output pressure P _o and the supply pressure P _s is increased tends to decrease gradually. That is, the characteristic shown in FIG. 7 is opposite to the characteristic shown in FIG.

Accordingly, the nozzle 45 and the flapper 60
Nozzle flapper signal pressure P _iConstant of the characteristic of
And the supply pressure P of the valve body shown in FIG._sOutput for
Pressure P_oBy skillfully selecting the proportional constant of the characteristic of
As shown in the figure, a regulating valve with flat characteristics
can get. Such a characteristic is caused by the supply pressure P_sThe change of
Output pressure P at 0 point_oIs a characteristic that makes
You.

[0042] According to such a characteristic, it is possible to substantially constant value the output pressure P _o of even zero point the supply pressure P _s is changed. Therefore, by adopting such characteristics, not only can the stability of the zero point of the regulating valve be secured,
The closed loop control eliminates the need to set the value of the output pressure _{Po at} the zero point to a constant value. Alternatively, there is no need for a special adjusting device for _{keeping the} supply pressure Ps applied through the supply port 11 constant.

As shown in FIG. 2, the input diaphragm 1
Effective area A of 7 effective area A ₁ and the output diaphragm 20
₂ and A ₁ = A ₂ ,
When the K _o = 0.068, further △ A / A ₂ a and 0.24, (13) is represented as follows.

P _o = 0.068 P _s ^2/3 −0.024 P _s (14) FIG. 9 shows the above equation (14) in a graph.
As is apparent from this equation, the change in the value of the output pressure P _o of the 0-point by the signal pressure P _s has become extremely small, it is possible to be regarded as practically almost constant value. That also supply pressure P _s is changed, 0 as a general characteristic of the regulating valve
The change in the output pressure _{Po at} the point is almost negligible.

[0045]

According to one aspect of the present invention, there is provided a control valve for extracting an output corresponding to an electric signal supplied from the outside, wherein an electromagnetic nozzle flapper in which a signal pressure at a zero point increases as a supply pressure increases, A valve body that reduces the output pressure at point 0 when the pressure increases, and uses the back pressure of the nozzle of the electromagnetic nozzle flapper as the signal pressure of the valve body.

Accordingly, the characteristics of the electromagnetic nozzle flapper and the characteristics of the valve body function so as to cancel each other out, thereby making it possible to reduce the influence of the change in the supply pressure on the change in the output pressure.

According to another aspect of the invention, the proportional constant of the change of the signal pressure at the zero point with respect to the supply pressure of the electromagnetic nozzle flapper and the proportional constant of the change of the output pressure at the zero point with respect to the supply pressure of the valve body are substantially opposite to each other. In addition, the characteristics of the electromagnetic nozzle flapper and the characteristics of the valve body are adjusted so that the effects of changes in the supply pressure are almost canceled when combined.

Therefore, the change in the signal pressure at the zero point of the nozzle flapper and the change in the output pressure of the valve body when the supply pressure changes are offset each other. Therefore, regardless of the change in the supply pressure, the output pressure at the zero point does not change. There is no change. Therefore, the zero point is stably secured irrespective of the change in the supply pressure, and it is not necessary to perform closed loop control or provide a mechanism for maintaining the supply pressure constant.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a configuration of a regulating valve.

FIG. 2 is a longitudinal sectional view of a regulating valve in which an input diaphragm and an output diaphragm have the same area.

FIG. 3 is a graph showing a change in signal pressure with respect to a change in signal current of a nozzle flapper.

FIG. 4 is a graph showing a change in a signal pressure at a point 0 with respect to a change in a supply pressure of a nozzle flapper.

FIG. 5 is a graph showing specific zero-point characteristics of a nozzle flapper.

FIG. 6 is a graph showing a change in output pressure with respect to a signal pressure of a valve body.

FIG. 7 is a graph showing a change in an output pressure at a point 0 with respect to a signal pressure of a valve body.

FIG. 8 is a graph showing the overall characteristics of the output pressure at point 0.

FIG. 9 is a graph showing specific overall characteristics of a regulating valve.

[Explanation of symbols]

 Reference Signs List 10 Body 11 Supply port 12 Output port 16 First recess 17 Input diaphragm 18 Pressure plate 19 Center boss 20 Output diaphragm 21 Small hole 22 Second recess 23 Receiving plate 24 Spring 25 Pressure plate 26 Rod 27 Poppet 28 Third recess 29 Through-hole 30 O-ring 35 Projection 36 Balance diaphragm 37 Spring receiver 38 Cancel spring 40 Center hole 41 Center hole 45 Nozzle 46 Center hole 47 Holder 48 Upper body 49 Recess 50 Horizontal hole 51 Communication groove 52 Port 53 Restriction passage 54 Communication passage 60 Flapper 61 Opening 62 Casing 63 Yoke 64 Magnet 65 Center core 66 Coil 67 Bobbin 68 Small hole

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 3H056 AA02 AA07 BB02 BB24 BB32 CA07 CA13 CB02 CB07 CC15 CD04 CD06 DD04 EE06 GG02 3H059 AA09 BB05 BB07 BB22 CA24 CD05 CD12 CE04 CE05 DD17 EE13 FF04 CC12 CB04 CC05 CB12 CC15 CD01 3H106 DA03 DA23 DA26 DB02 DB12 DB32 DC05 DC17 DD06 EE34 GA08 GA10 GB06 GB11 GC14 HH08 5H316 BB02 DD06 EE02 EE10 EE12 EE20 JJ03 JJ04 JJ07 JJ13 KK02

Claims (8)

[Claims] 1. An adjusting valve which takes out an output corresponding to an electric signal supplied from the outside, wherein an electromagnetic nozzle flapper in which a signal pressure at a point 0 increases when the supply pressure increases, and a point 0 when the supply pressure increases. And a valve body for reducing the output pressure of the electromagnetic nozzle flapper, wherein a back pressure of the nozzle of the electromagnetic nozzle flapper is used as a signal pressure of the valve body. 2. The method according to claim 1, wherein the pressure is 0 to the supply pressure of the electromagnetic nozzle flapper.
The proportionality constant of the change of the signal pressure at the point and the proportionality constant of the change of the output pressure at the zero point with respect to the supply pressure of the valve body are substantially opposite to each other. 2. The regulating valve according to claim 1, wherein a characteristic of the electromagnetic nozzle flapper and a characteristic of the valve body are adjusted so as to cancel each other. 3. The regulating valve according to claim 1, wherein the flapper of the electromagnetic nozzle flapper is moved in the axial direction by a coil of the linear motor to adjust a gap between the flapper and the tip of the nozzle. 4. The regulating valve according to claim 1, wherein a supply pressure is applied as a working pressure to a nozzle of the electromagnetic nozzle flapper, and a back pressure of the nozzle is taken out as a signal pressure. 5. The valve body includes an input diaphragm receiving a signal pressure and an output diaphragm receiving an output pressure.
The input diaphragm and the output diaphragm are arranged so as to press each other via a rigid body that transmits force, and further include a balance diaphragm that receives a supply pressure,
The regulating valve according to claim 1, wherein the balance diaphragm presses the output diaphragm toward an input diaphragm via a pressure plate. 6. The regulating valve according to claim 5, wherein the effective area of the balance diaphragm is sufficiently smaller than the effective areas of the input diaphragm and the output diaphragm. 7. The regulating valve according to claim 5, further comprising a poppet, which is connected to the pressure plate via a rod slidably supported in a guide hole in the body. . 8. The poppet according to claim 5, wherein one of the pressure plate and the poppet connected to each other by a rod is pressed by a spring so as to negate the weight of both.
The regulating valve according to 1.