JP3160276U - Pressure control valve - Google Patents

Abstract

An object of the present invention is to suppress the opening of a valve seat when the fluid pressure on the secondary side downstream of the pressure control valve becomes higher than the set pressure on the primary side without contaminating the fluid flow path, and to reduce the fluid pressure on the primary side. Provided is a pressure control valve that realizes suppression of an increase in internal volume of a flow path in a control valve due to influence by a simple mechanism. A poppet valve section having a valve chamber 20 having an inflow section 21 and an outflow section 22, a valve seat 23 formed therebetween, a valve shaft 31, a seal section 33 for sealing the valve seat so as to be movable back and forth, and a pressure receiving section 34. 32, a valve mechanism 30 including a diaphragm portion 35 mounted in the valve chamber, and a poppet valve portion which is provided outside the valve chamber of the diaphragm portion and constantly energizes the valve mechanism body and by the inflow pressure of the controlled fluid on the primary side And an urging means 40 for opening the seal portion of the valve mechanism, and the diameter distance SD of the seal portion of the poppet valve portion of the valve mechanism body is a diameter at a position obtained by dividing the maximum diameter of the membrane portion of the diaphragm portion and the minimum diameter of the membrane portion. The size is set to be within 10% of the distance MD. [Selection] Figure 1

Description

  The present invention relates to a pressure control valve.

  In the manufacture of semiconductors and the like, when supplying fluid such as pure water and chemicals for cleaning silicon wafers, it is necessary to accurately control the flow rate and pressure of the supply fluid. Fluctuations in fluid pressure greatly affect product yield.

  Conventionally, there is a pressure control valve 70 functioning as a relief valve disclosed in FIG. 3 as an apparatus for controlling (holding) a primary fluid to a predetermined pressure state. The pressure control valve 70 includes a first chamber 72 having a fluid inflow portion 73 on the primary side, a second chamber 74 having a fluid outflow portion 75 on the secondary side, and the first chamber 72 and the second chamber 74. A communication passage 76 having a valve seat 77 is formed. On the first chamber 72 side of the communication passage 77, a valve mechanism 80 including a valve portion 81 that opens and closes the valve seat 77 and a diaphragm portion 82 that is connected to the first passage 72 and is disposed on the first chamber 72 side is disposed. The valve mechanism 82 is constantly biased toward the valve seat 77 by a pressurizing means such as a pressure adjusting gas 93 or a spring (not shown) and is maintained in a seated state.

  When the fluid pressure on the primary side rises higher than the urging force to the valve mechanism 80, the valve portion 81 is separated from the valve seat 77, and the fluid flows out from the outflow portion 75 via the second chamber 74. However, in the pressure control valve 70 of FIG. 3, the fluid pressure on the secondary side downstream of the pressure control valve may be higher than the set pressure on the primary side (the urging force to the valve mechanism). In this case, when the valve mechanism 80 (valve portion 81) receives the secondary pressure, the valve seat 77 is opened, and as a result, pressure control becomes difficult.

  In addition, an on-off valve may be installed downstream of the pressure control valve 70 in this example. When the on-off valve is closed, the diaphragm portion 82 is lifted upward due to the influence of the fluid pressure on the primary side, and the internal volume of the communication passage 76 is increased. Then, when the opening / closing valve is opened, the fluid of the increased volume is pushed out regardless of the control of the control valve, and the control accuracy of the fluid is lowered.

  Furthermore, a control valve that includes a piston portion 120 above the diaphragm portion 115 and suppresses fluctuations that occur in the valve mechanism 110 has been proposed as in the pressure control valve 100 of FIG. The pressure control valve 100 communicates the first chamber 103 having the fluid inflow portion 101 on the primary side, the second chamber 104 having the fluid outflow portion 102 on the secondary side, and the first chamber 103 and the second chamber 104. Thus, a communication passage 106 having a valve seat 105 is formed. On the first chamber 103 side of the communication passage 106, a valve mechanism 110 including a valve portion 111 that opens and closes the valve seat 105 and a diaphragm portion 115 that is connected to the first passage 103 and is disposed on the first chamber 103 side is disposed.

  A piston portion 120 is provided above the valve mechanism 110 and is slidably accommodated on the inner surface of the piston accommodating portion 121 of the pressure control valve 100. The valve mechanism 110 is always urged toward the valve seat 105 by a pressurizing means such as the pressure adjusting gas 130 and is maintained in the seated state. Sealing members 123 and 124 such as O-rings are attached to the piston part 120 so that the advancing / retreating operation of the piston part in the piston housing part 121 is stabilized. Reference numerals 125 and 126 are vent holes.

  However, even in the case of the pressure control valve 100, similarly to the pressure control valve 70 of FIG. 3, the pressure control becomes difficult due to the fluctuation of the secondary side fluid pressure downstream of the pressure control valve. In addition, since the seal members 123 and 124 are attached to the pressure control valve 100, the sliding resistance between the piston part 120 and the piston housing part 121 is increased, and the valve mechanism 110 connected to the piston part 120 is improved. A decrease in control accuracy is also pointed out.

  In order to cope with the problems existing in the pressure control valve having the conventional structure, a pressure control valve in which diaphragm portions are arranged on both the primary side and the secondary side has been proposed (see Patent Document 1). According to the control valve of this document, it is possible to control the fluid pressure on the primary side without being influenced by the fluid pressure on the secondary side. However, the structure of the pressure control valve itself tends to be complicated.

Japanese Patent No. 3467438

  The present invention has been made in view of the above points, and the valve seat in the case where the fluid pressure on the secondary side downstream of the pressure control valve becomes higher than the set pressure on the primary side without contaminating the flow path of the fluid. The pressure control valve that realizes the suppression of the opening of the valve and the increase in the internal volume of the flow path in the control valve due to the influence of the fluid pressure on the primary side is realized by a simple mechanism.

  That is, the invention of claim 1 is a valve having an inflow portion for a controlled fluid on the primary side and an outflow portion for the controlled fluid on the secondary side, and a valve seat formed between the inflow portion and the outflow portion. A chamber, a valve shaft, a seal portion that is formed in a bulging shape on the valve seat side of the valve shaft and seals the valve seat on one side so as to be able to advance and retract, and a controlled fluid pressure from the outflow portion side on the other side. A valve mechanism including a poppet valve portion having a pressure receiving portion; a diaphragm portion formed on the opposite side to the valve seat side of the valve shaft and mounted in the valve chamber; and on the outer side of the valve chamber of the diaphragm portion Provided with a biasing means for constantly biasing the valve mechanism body and opening the seal portion of the poppet valve portion by the inflow pressure of the controlled fluid on the primary side, of the seal portion of the poppet valve portion of the valve mechanism body The diameter distance (SD) is the maximum diameter of the membrane part of the diaphragm part and the minimum straight line of the membrane part. The according to the pressure control valve, characterized in that formed on the magnitude to be within ± 10% of the diameter distance (MD) in 2 minutes position.

  The invention according to claim 2 relates to the pressure control valve according to claim 1, wherein the biasing means is one or both of a spring and a pressure adjusting gas.

  The invention according to claim 3 is the pressure control according to claim 1 or 2, wherein in the diaphragm portion, a film portion of the diaphragm portion and an outer peripheral portion of the diaphragm portion are formed with a step through an upright portion. Related to the valve.

  According to the pressure control valve according to the first aspect of the present invention, there is an inflow portion of the controlled fluid on the primary side and an outflow portion of the controlled fluid on the secondary side, and a valve seat between the inflow portion and the outflow portion. A valve chamber in which the valve seat is formed, a seal portion that is formed in a bulging shape on the valve seat side of the valve shaft and seals the valve seat on one side so as to be movable forward and backward, and a cover portion from the outflow portion side on the other side. A valve mechanism having a pressure receiving portion for receiving a control fluid pressure; a diaphragm portion formed on the opposite side of the valve seat to the valve seat side and mounted in the valve chamber; and the diaphragm portion A poppet valve portion of the valve mechanism provided with an urging means that is provided outside the valve chamber and constantly biases the valve mechanism body and opens a seal portion of the poppet valve portion by an inflow pressure of a controlled fluid on the primary side. The diameter distance (SD) of the seal portion of the diaphragm portion and the maximum diameter of the membrane portion of the diaphragm portion Since the minimum diameter of the part is formed to be within ± 10% of the diameter distance (MD) at the position where the diameter is divided into two, the fluid pressure on the secondary side downstream of the pressure control valve is reduced without contaminating the fluid flow path. A simple mechanism can suppress the opening of the valve seat when the pressure is higher than the set pressure on the primary side, and further suppress the increase in the internal volume of the flow path in the control valve due to the influence of the fluid pressure on the primary side.

  According to the pressure control valve according to the second aspect of the present invention, in the device according to the first aspect, the biasing means is either one or both of a spring and a pressure-regulating gas. Can be In addition, the operation control of the valve mechanism is facilitated.

  According to the pressure control valve according to the invention of claim 3, in the invention according to claim 1 or 2, in the diaphragm part, the film part of the diaphragm part and the outer peripheral part of the diaphragm part are stepped through the standing part. Since it is provided and formed, the replacement characteristics of the controlled fluid in the valve chamber can be enhanced, and the retention of excess fluid can be suppressed.

It is a longitudinal cross-sectional view of the pressure control valve which concerns on one Example of this invention. It is a longitudinal cross-sectional view of the open state of the pressure control valve. It is a longitudinal cross-sectional view of the conventional pressure control valve. It is a longitudinal cross-sectional view of the other conventional pressure control valve.

  A pressure control valve 10 of the present invention shown in FIGS. 1 and 2 is mainly disposed in a fluid pipe line of a semiconductor manufacturing factory or the like, and the flow of a controlled fluid such as pure water or a chemical flowing through the pipe line is unidirectional. It is a valve that keeps the fluid pressure of the controlled fluid on the primary side (upstream side) of the pressure control valve constant (only in the forward direction). The pressure control valve 10 includes a valve chamber 20, a valve mechanism 30, and an urging means 40. The valve chamber 20 of the pressure control valve of the embodiment is formed inside the body body 11 made of a fluororesin such as PTFE having high corrosion resistance and chemical resistance. The valve chamber 20 has an inflow portion 21 and an outflow portion 22 for a controlled fluid, and a valve seat 23 is formed between the inflow portion 21 and the outflow portion 22.

  The valve mechanism body 30 is formed of a resin such as a fluororesin, like the body body 11, and includes a valve shaft 31, a poppet valve portion 32, and a diaphragm portion 35. The poppet valve portion 32 is formed in a bulging shape on the valve seat side (front side) of the valve shaft 31, and a seal portion 33 is formed on one side (lower side in the drawing) to seal the valve seat 23 so as to be able to advance and retract. A pressure receiving portion 34 that receives the controlled fluid pressure from the outflow portion 22 is formed on the other side (the illustrated valve shaft side). In this embodiment, as can be understood from the drawing, the front side of the poppet valve portion 32 is formed in a tapered shape that becomes narrower toward the front end, and a part of the inclined surface can be seated and separated from the valve seat 23. Part 33.

  The urging means 40 is provided outside the valve chamber 20 of the diaphragm portion 35, constantly urges (pressurizes in the embodiment) the valve mechanism 30 in the forward direction x (downward arrow in the drawing), and flows in the controlled fluid. Adjustment is performed to open the seal portion 33 of the poppet valve portion 32, that is, the flow path from the inflow portion 21 to the outflow portion 22 by the increase in pressure. As defined in the invention of claim 2, one or both of the spring 41 and the pressure adjusting gas 45 are used for the biasing means. The embodiment discloses an example in which both are applied.

  An urging receiving portion 50 connected to the valve shaft 31 of the valve mechanism 30 is connected above the diaphragm portion 35 of the pressure control valve 10 of the present invention, and the urging receiving portion 50 forms a space portion 55. The upper body 51 is accommodated so as to freely advance and retract. A spring holding portion 53 is formed at the rear portion of the bias receiving portion 50 of the embodiment, and a spring 41 that is one of the biasing means 40 is attached to the spring holding portion 53. When the spring 41 is sandwiched between the upper body 51 and the bias receiving portion 50, a biasing force is generated in the spring 41. The biasing force of the spring 41 is transmitted to the poppet valve portion 32 of the valve shaft 31 connected to the tip portion 52 of the bias receiving portion 50 by screwing or the like. Thus, there is an effect that the seal portion 33 of the poppet valve portion 32 is always seated on the valve seat 23.

  In the embodiment, the pressure adjusting air mechanism A is used to create the pressure adjusting gas 45 of the biasing means 40 that arbitrarily moves and adjusts the bias receiving portion 50 in the forward direction (downward direction x) and the backward direction (upward direction y). Is provided. The pressure adjusting air mechanism A includes a supply source for supplying a pressure adjusting gas (in this example, a pressurized gas), and an adjustment / control device 46 such as an electropneumatic converter or an electropneumatic regulator for adjusting / controlling the pressure of the pressure adjusting gas. have.

  Reference numeral P in the figure denotes a port portion for supplying pressure-controlled gas to the space portion 55, and 56 denotes a breathing hole for taking in and out the air in the space portion to the outside. Although illustration is omitted, when only the pressure adjusting gas is used as the urging means, it is possible to omit the urging receiving portion 50 of the embodiment and directly press the diaphragm portion 35 of the valve mechanism 30.

  The diaphragm portion 35 is formed on the rear side of the poppet valve portion 32 of the valve shaft 31 and is mounted in the valve chamber 20. The diaphragm portion 35 has a thin film portion (movable portion) 36 that is a diaphragm surface and an outer peripheral portion 37 on the outer peripheral side thereof, and is made of a resin such as a fluororesin, like the valve mechanism 30 and the body body 11. It is formed. In the embodiment, the outer peripheral portion 37 of the diaphragm portion 35 is sandwiched and fixed between the body body 11 and the upper body 51. Further, as defined in the invention of claim 3, the film portion 36 of the diaphragm portion 35 and the outer peripheral portion 37 thereof are formed with each other via a step portion 38 having a step Δ.

  The step portion 38 brings the membrane portion 36 in the diaphragm portion 35 closer to the valve chamber 20 side. As can be understood from the drawing, the internal volume of the valve chamber 20 above the pressure receiving portion 34 of the poppet valve portion 32 can be reduced. That is, it is possible to enhance the replacement characteristics of the controlled fluid in the valve chamber and suppress the retention of excess fluid. In addition, the amount of fluid pushed out due to an increase in internal volume accompanying a change in the pressure of the primary controlled fluid can be suppressed. Therefore, it is desirable from the viewpoint of maintaining the cleanliness of the fluid and controlling accuracy.

  In particular, as defined in the pressure control valve 10 of the present invention, the diameter distance of the seal portion 33 of the poppet valve portion 32 (in the example shown, the distance equal to the opening diameter (orifice diameter) inside the valve seat 23) SD is the diaphragm portion. A size within ± 10% with respect to the diameter distance MD at a position obtained by dividing the maximum diameter L1 of the membrane portion 36 and the minimum diameter L2 of the membrane portion 36 into an effective diameter of 35, preferably both are the same Formed in size. In the illustrated embodiment, the diameter distance SD and the diameter distance MD are the same. The diameter distance MD at the position obtained by dividing the membrane portion 36 maximum diameter L1 of the diaphragm portion 35 and the minimum diameter L2 of the membrane portion 36 into two can be considered as an effective pressure receiving diameter of the membrane portion 36 of the diaphragm portion.

  Control and adjustment of the fluid pressure of the controlled fluid in the pressure control valve 10 are performed by a forward force (downward x) applied to the valve mechanism 30 by the biasing means 40 and a seal portion 33 (diameter distance) of the poppet valve portion 32. This is performed by balancing with the force acting in the backward direction (upward direction y) of the valve mechanism 30 applied to the area of SD).

  When the fluid pressure on the inflow portion 21 side (primary side) becomes a predetermined value or more, as shown in FIG. By acting in the (upward direction y), the seal portion 33 of the poppet valve portion 32 is separated from the valve seat 23. Therefore, a fluid circulation space is created between the seal portion 33 and the valve seat 23. Therefore, the controlled fluid can be circulated from the inlet 21 toward the outlet 22 (forward direction). As can be seen from the drawing, the controlled fluid is in contact with only the valve chamber 20, the diaphragm 35 and the like of the body body 11, so that the cleanliness is maintained.

  In the case where the pressure of the controlled fluid on the secondary side of the pressure control valve 10 (downstream of the outflow portion 22) rises and a back flow is generated from the secondary side toward the pressure control valve 10, as in the present invention, the diaphragm The diameter distance MD, which is the effective pressure receiving diameter of the membrane portion 36, and the diameter distance SD of the seal portion 33 are within ± 10%, and preferably both are the same size (SD = MD). The pressure in the upward direction y received by the membrane part (proportional to the area calculated from the diameter distance MD of the effective pressure receiving diameter) and the pressure in the downward direction x received by the pressure receiving part 34 of the poppet valve part 32 (diameter distance of the seal part) (The opening diameter of the valve seat) is proportional to the area calculated from SD) and is balanced.

  Therefore, even if the fluid pressure on the secondary side of the pressure control valve fluctuates, the pressure applied to the valve mechanism itself cancels out, reducing the effect of the poppet valve part moving forward and backward (opening and closing of the valve seat). Is done. Therefore, in the pressure control valve of the present invention, the fluid pressure of the controlled fluid on the primary side of the pressure control valve and the pressure fluctuation thereof are not affected by the fluid pressure fluctuation on the secondary side of the pressure control valve. The poppet valve part (valve mechanism) can be moved back and forth in response to only the flow of the controlled fluid in only one direction (forward direction), and the controlled fluid on the primary side (upstream side) of the pressure control valve Fluid pressure can be kept constant.

DESCRIPTION OF SYMBOLS 10 Pressure control valve 20 Valve chamber 21 Inflow part 22 Outflow part 23 Valve seat 30 Valve mechanism 31 Valve shaft 32 Poppet valve part 33 Seal part 34 Pressure receiving part 35 Diaphragm part 36 Film | membrane part 37 Outer peripheral part 38 Step part 40 Energizing means 41 Spring 45 Pressure-regulating gas 50 Energizing receiving portion SD Diameter distance of the seal part of the poppet valve part MD Diameter distance at the position where the maximum and minimum diameters of the membrane part of the diaphragm part are divided into two

Claims (3)

A valve chamber having an inflow portion of the controlled fluid on the primary side and an outflow portion of the controlled fluid on the secondary side, and forming a valve seat between the inflow portion and the outflow portion;
A valve shaft, a seal portion that is formed in a bulging shape on the valve seat side of the valve shaft, and seals the valve seat on one side so as to be able to advance and retreat; A valve mechanism comprising: a poppet valve portion having a diaphragm portion that is formed on the opposite side to the valve seat side of the valve shaft and is mounted in the valve chamber;
An urging means that is provided outside the valve chamber of the diaphragm portion and constantly urges the valve mechanism body and opens a seal portion of the poppet valve portion by an inflow pressure of a primary controlled fluid;
The diameter distance (SD) of the seal part of the poppet valve part of the valve mechanism is within ± 10% of the diameter distance (MD) at a position obtained by dividing the maximum diameter of the membrane part of the diaphragm part and the minimum diameter of the membrane part. A pressure control valve characterized in that it is formed in the size of   The pressure control valve according to claim 1, wherein the urging means is one or both of a spring and a pressure adjusting gas.   The pressure control valve according to claim 1 or 2, wherein in the diaphragm portion, a film portion of the diaphragm portion and an outer peripheral portion of the diaphragm portion are formed with a step through an upright portion.

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