JP3590572B2 - Check valve structure - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a check valve structure that restricts the flow of a fluid only in a forward direction by a valve body and prevents the flow in the reverse direction.
[0002]
[Prior art]
For example, in a pipeline in a factory that handles ultrapure water or chemicals, such as a semiconductor manufacturing factory, a non-return that prevents a backflow by restricting the flow of a fluid flowing through the pipeline to only one direction (forward direction). Valves may be provided.
[0003]
Conventionally, a check valve 50 as shown in FIG. The check valve 50 includes a valve chamber 51 having an inlet 52 and an outlet 53 for a controlled fluid, a spherical valve body 55 that opens and closes the inlet 52 and receives fluid pressure from the outlet 53. And a spring 60 provided in the valve chamber 51 and constantly biasing the valve body 55 in the inflow port closing direction. In the illustrated example, the valve chamber 51 is formed by a first block 51a having an inlet 52 formed therein, and a second block 51b screwed to the first block 51a and having an outlet 53 formed therein. . In the drawing, reference numeral 54 denotes a valve seat, and 61 denotes a seal member such as packing interposed between the first block 51a and the second block 51b.
[0004]
In the check valve 50, when the fluid pressure on the inflow port 52 side (primary side) becomes equal to or more than a predetermined value, the valve body 55 is separated from the valve seat 54 by overcoming the urging force of the spring 60, and the inflow port 52 is closed. By opening, the controlled fluid flows to the outlet 53. On the other hand, when the fluid pressure on the outlet 53 side (secondary side) becomes higher than the fluid pressure on the inlet 52 side, the controlled fluid on the outlet 53 side tends to flow back to the inlet 52 side. The valve body 55 is seated on the valve seat 54 by the flow and pressure of the fluid to close the inflow port 52, thereby preventing the controlled fluid from flowing back to the inflow port 52 side.
[0005]
However, in the conventional check valve 50, since the spring 60 for urging the valve body 55 is disposed in the valve chamber 51, the spring 60 comes into contact with the fluid. When the spring 60 comes in contact with the fluid to be controlled in this way, there is a concern that fine dust or debris called particles are mixed into the fluid to be controlled due to corrosion or deterioration of the spring 60. In particular, when ultrapure water or a high-purity chemical is used as the fluid to be controlled, the above problem becomes a serious problem. Further, the check valve 50 cannot open and close the inflow port 52, that is, cannot control the valve element 55 freely, but there is a demand from the user to freely control the valve element.
[0006]
[Problems to be solved by the invention]
The present invention has been proposed in view of the above points, has no risk of generating fine dust, and can be used optimally when ultra-pure water or a high-purity chemical is used as a controlled fluid, and can be freely used. It is an object of the present invention to provide a novel check valve structure capable of controlling a valve element.
[0007]
[Means for Solving the Problems]
That is, according to the invention of claim 1, the inlet of the controlled fluid (21) and the outlet (22) have a said inlet valve chamber in which the valve seat (23) is formed between the outlet (20 ) , A valve shaft (31) , a sealing portion (33) formed in a bulging shape on the valve shaft and opening and closing the valve seat on the front side, and a pressure receiving portion (34) receiving fluid pressure from the outlet on the rear side. ) and a valve portion (32) having said valve shaft and is formed integrally the valve diaphragm mounted in the room on the opposite side of the valve portion (35) poppet (30 to have a and), and a pressure regulating means for opening the sealing portion of the valve portion by the inflow pressure of the constantly advancing direction regulating pressure and the controlled fluid the poppet valve body provided in the valve chamber outside of the diaphragm portion (40), said poppet valve body The diameter distance (SD) of the seal part of the valve part is determined by comparing the maximum diameter of the diaphragm part with the diaphragm part. The diameter is formed to be larger than the diameter distance (MD) at the position where the small diameter is divided into two, and a force acting on the valve portion from the controlled fluid in the valve body forward direction (X) is applied to the membrane of the diaphragm portion from the controlled fluid. The present invention relates to a check valve structure characterized in that a force acting on a portion in a valve body retreating direction (Y) is made larger .
[0008]
According to a second aspect of the present invention, in the first aspect, the pressure adjusting means comprises a piston formed integrally with the valve shaft, a cylinder portion into which the piston is inserted, and a drive mechanism for adjusting the pressure of the piston. Related to stop valve structure.
[0009]
Further, the invention according to claim 3 relates to the check valve structure according to claim 2, wherein the drive mechanism for adjusting the pressure of the piston is a spring body that constantly biases the piston in the forward direction.
[0010]
Still further, the invention according to claim 4 relates to the check valve structure according to claim 2 or 3, further comprising a pressure adjusting air mechanism capable of adjusting the movement of the piston of the pressure adjusting means in the forward and backward directions.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a longitudinal sectional view showing an open state of a check valve according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view showing a closed state of the check valve, and FIG. 3 is a check section according to another embodiment. It is a longitudinal section showing a valve.
[0012]
The check valve 10 shown in FIG. 1 and FIG. 2 relates to an embodiment of the present invention, and is disposed in a pipe or the like in a semiconductor manufacturing plant or the like, and controls the flow of a controlled fluid flowing through the pipe or the like. The backflow is prevented by restricting only in the direction (forward direction). The check valve 10 includes a valve chamber 20, a poppet valve body 30, and a pressure adjusting unit 40. In the embodiment, the valve chamber 20 is formed inside the body 11 made of a resin having high corrosion resistance and high chemical resistance such as fluororesin.
[0013]
The valve chamber 20 has an inlet 21 and an outlet 22 for a controlled fluid, and a valve seat 23 is formed between the inlet 21 and the outlet 22.
[0014]
The poppet valve body 30 is formed of a resin having high corrosion resistance and chemical resistance, such as a fluororesin, similarly to the body body 11, and has a valve shaft 31, a valve portion 32, and a diaphragm portion 35. The valve portion 32 is formed in a bulging shape on one end side (front side) of the valve shaft 31, and a seal portion 33 for opening and closing the valve seat 23 is formed on the front side, and the outlet port is provided on the rear side. A pressure receiving portion 34 that receives the fluid pressure from 22 is formed. In this embodiment, as can be understood from the figure, the front side of the valve portion 32 is formed in a tapered shape tapering toward the front end, and a part of the inclined surface 32a obtained thereby is seated on and separated from the valve seat 23. It is a seal portion 33 that can be seated. Further, in the embodiment, a flat rear end face of the valve portion 32 is the pressure receiving portion 34.
[0015]
The diaphragm portion 35 is formed integrally with the valve shaft 31 on the opposite side (rear side) of the valve shaft 31 from the valve portion 32, 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. Further, in the embodiment, the outer peripheral portion 37 of the diaphragm portion 35 is sandwiched and fixed between the body 11 and a cylinder portion 42 of the pressure adjusting means 40 described later.
[0016]
In the check valve 10 according to the present invention, the diameter distance (the distance equal to the opening diameter (orifice diameter) inside the valve seat 23 in the illustrated example) SD of the seal part 33 of the valve part 32 is equal to the diaphragm part. A diameter distance MD at a position where the maximum diameter L1 of the film portion 36 and the minimum diameter L2 of the film portion 36 of the diaphragm portion 35, which is the effective diameter 35, is divided into two, is formed. The diameter distance MD at a position obtained by dividing the maximum diameter L1 of the membrane portion 36 of the diaphragm portion 35 and the minimum diameter L2 of the membrane portion 36 into two can be considered as a so-called effective pressure receiving diameter of the membrane portion 36 of the diaphragm portion 35. If the diameter distance SD of the seal portion 33 is made larger than the diameter distance MD of the diaphragm portion 35 based on the diameter distance MD (SD> MD), the valve body is moved from the controlled fluid to the film portion 36 of the diaphragm portion 35. The force acting on the valve portion 32 in the valve body forward direction (downward in the figure) X from the controlled fluid becomes larger than the force acting in the backward direction (upward in the figure) Y. Therefore, when the fluid pressure on the outlet 22 side (secondary side) becomes higher than the fluid pressure on the inlet 21 side and the controlled fluid on the outlet 22 side tries to flow back to the inlet 21 side, the valve 30 force acts in X (downward in the drawing) the valve body forward direction, the valve unit 32 it is possible to prevent backflow of the controlled fluid seated on the valve seat 23.
[0017]
The pressure adjusting means 40 is provided outside the valve chamber 20 of the diaphragm portion 35, constantly adjusts the pressure of the poppet valve body 30 in the forward direction X (pressurizes in the embodiment), and controls the valve portion by the inflow pressure of the fluid to be controlled. It is configured to open 32 seal portions 33, that is, the inflow port 21. In this embodiment, the pressure adjusting means 40 adjusts the pressure of the piston 41 integrally formed with the valve shaft 31 of the poppet valve body 30, the cylinder portion 42 into which the piston 41 is inserted, and the piston 41. And a driving mechanism 43 for applying pressure in the embodiment. In the illustrated example, the piston 41 is screwed to a rear portion (an upper portion in the illustrated example) of the valve shaft 31. Needless to say, the method of connecting the piston 41 and the valve shaft 31 is not limited to the screw connection described above. For example, the piston 41 and the valve shaft 31 may be integrally formed. The cylinder portion 42 is fixed to the body 11 by appropriate means.
[0018]
Further, in the embodiment, a spring receiving portion 41d is provided on the rear side (upper side in the figure) of the piston 41, and a spring which constantly urges the piston 41 in the forward direction (downward direction in the figure) X by the spring receiving portion 41d. The body is provided as a drive mechanism 43 that regulates (presses in this example) the piston 41. Further, in this embodiment, a pressure adjusting air mechanism (in this example, a pressurized air mechanism) capable of arbitrarily adjusting the movement of the piston 41 in a backward direction (upward in the figure) and a forward direction (downward in the figure). A) is provided. The pressure regulating air mechanism A includes a supply source A1 for supplying a pressure regulating gas (in this example, a pressurized gas) and an adjustment / control of an electropneumatic converter or an electropneumatic regulator for regulating / controlling the pressure of the pressure regulating gas. It has the device A2. Reference numeral P1 in the drawing denotes a first pressure supply gas to a space between a rear portion (large-diameter portion) 41a of the piston 41 and the inner wall of the cylinder portion 42 and a discharge pressure gas from the space. A port P2 is a second port 44 for supplying a pressure-regulated gas to a space between the central portion (small diameter portion) 41b of the piston 41 and the inner wall of the cylinder portion 42 and discharging the pressure-regulated gas from the space. Sealing member such as packing interposed between the rear portion 41a of the piston 41 and the inner wall of the cylinder portion 42, sealing member 45 such as packing interposed between the front portion 41c of the piston 41 and the inner wall of the cylinder portion 42, 46 It is a breathing hole formed to allow air in the rear (outer) space of the diaphragm 35 to enter and exit outside.
[0019]
The drive mechanism 43 for adjusting the pressure of the piston 41 is not limited to a spring body. The drive mechanism 43 may adjust the pressure of the piston 41 only with the pressure-adjusted gas by the pressure-adjusted air mechanism A, or may adjust the load. The pressure of the piston 41 may be adjusted by a spring device or a solenoid. When a load-adjustable spring device is used as the driving mechanism 43, a servo motor or the like may be connected to the load-adjustable spring device so that the spring constant can be automatically controlled.
[0020]
Next, an operation example of the check valve 10 having the above structure will be described.
In the check valve 10, when the fluid pressure on the inflow port 21 side (primary side) becomes a predetermined value or more, as shown in FIG. The seal portion 33 of the valve portion 32 of the valve body 30 is separated from the valve seat 23, and the seal portion 33 of the valve portion 32 is opened (more specifically, fluid flow between the seal portion 33 and the valve seat 23). By forming a space), the controlled fluid flows from the inlet 21 to the outlet 22 (forward direction).
[0021]
On the other hand, if the fluid pressure on the outlet 22 side (secondary side) becomes higher than the fluid pressure on the inlet 21 side, the controlled fluid on the outlet 22 side tends to flow back to the inlet 21 side. As described above, the diameter distance SD of the seal portion 33 of the valve portion 32 is formed to be larger than the diameter distance MD at a position where the maximum diameter L1 of the membrane portion 36 and the minimum diameter L2 of the membrane portion 36 of the diaphragm portion 35 are divided into two. Therefore, the force acting on the pressure receiving portion 34 of the valve portion 32 in the valve body forward direction X from the controlled fluid acts on the membrane portion 36 of the diaphragm portion 35 from the controlled fluid in the valve body retreating direction Y. 2, the valve portion 32 is seated on the valve seat 23 and the seal portion 33 of the valve portion 32 is closed, thereby preventing the controlled fluid from flowing backward.
[0022]
In the check valve 10, when the inflow port 21 is in the open state, the pressure adjusting air mechanism A causes the rear portion (large diameter portion) 41 a of the piston 41 to communicate with the inner wall of the cylinder portion 42 via the first port P 1. The piston 41 is pushed in the forward direction X, and the poppet valve body 30 moves forward, and the inflow port 21, more precisely, the seal portion 33 of the valve portion 32 is closed. On the other hand, when the inflow port 21 is in the closed state, the pressure adjusting gas is supplied to the space between the central portion (small diameter portion) 41b of the piston 41 and the inner wall of the cylinder portion 42 through the second port P2 by the pressure adjusting air mechanism A. By causing the inflow, the piston 41 is pushed in the retreating direction Y, and the poppet valve body 30 retreats, and the inflow port 21, or more precisely, the seal portion 33 of the valve portion 32 is opened. That is, in the check valve 10, the poppet valve body 30 can be freely controlled, and the inflow port 21 can be arbitrarily opened and closed.
[0023]
The present invention is not limited to the above-described embodiment, and can be implemented by appropriately changing a part of the configuration without departing from the spirit of the invention. For example, as in a check valve 10A shown in FIG. 3, a seal portion 33A of a valve portion 32A of a poppet valve body 30A is formed by a protrusion formed on a front end surface (outside of the front end surface in the figure) of the valve portion 32A. May be done. In this case, the diameter distance SD of the seal portion 33A of the valve portion 32A is equal to or larger than the opening diameter (orifice diameter) OD inside the valve seat 23. In FIG. 3, the same members as those in the embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted.
[0024]
Further, in the check valve 10 of the above embodiment, two ports P1 and P2 are provided between the piston 41 and the inner wall of the cylinder portion 42 for sending the pressure-regulated gas from the pressure-regulating air mechanism A. The movement of the piston 41 is adjusted by flowing the pressure-regulated gas between the piston 41 and the inner wall of the cylinder portion 42 from the ports P1 and P2. However, the present invention is not limited to this, and any one of the ports P1 and P2 is used. The pressure control gas from the pressure control air mechanism A flows in and out between the piston 41 and the inner wall of the cylinder portion 42 through the port, and pressurizes and depressurizes the piston 41, thereby moving the piston 41. Adjustment may be performed.
[0025]
【The invention's effect】
As described above, in the check valve structure according to the present invention, since there is no biasing means for biasing the valve element such as a spring in the valve chamber, fine dust is generated in the controlled fluid. And the liquid contacting part of the check valve can be made only of a material having high corrosion resistance or high chemical resistance. You can use it optimally.
[0026]
Further, as in the second and third aspects of the present invention, the pressure adjusting means for adjusting the pressure of the poppet valve element includes a piston formed integrally with the valve shaft of the poppet valve element, a cylinder portion into which the piston is inserted, and the piston. With a driving mechanism for adjusting the pressure, the poppet valve can be operated by adjusting the pressure of the poppet with a simple structure and efficiently. In particular, if the driving mechanism for adjusting the pressure of the piston is a spring body that constantly urges the piston in the forward direction, the structure can be further simplified and the cost is also advantageous. is there.
[0027]
Furthermore, if a pressure adjusting air mechanism that allows the piston of the pressure adjusting means to move and adjust in the forward and backward directions is provided as in the invention of claim 4, the poppet valve body can be freely controlled, and can be arbitrarily controlled. Since the inflow port can be opened and closed, a completely new use mode that has been impossible with the conventional check valve of this type is created, and the convenience of the check valve of this type is greatly improved. .
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a check valve according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view showing a closed state of the check valve.
FIG. 3 is a longitudinal sectional view showing a check valve according to another embodiment.
FIG. 4 is a longitudinal sectional view showing an example of a conventional check valve.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Check valve 20 Valve room 21 Inflow port 22 Outflow port 30 Poppet valve element 31 Valve shaft 32 Valve part 33 Seal part 34 Pressure receiving part 35 Diaphragm part 36 Membrane part 40 Pressure control means 41 Piston 42 Cylinder part 43 Drive mechanism A Pressure control Air mechanism SD Diameter distance of the seal part of the valve part MD Diameter distance at the position where the maximum diameter of the membrane part and the minimum diameter of the membrane part are divided into two

Claims (4)

The inlet of the controlled fluid (21) and the outlet (22) Yes and the valve seat (23) is formed a valve chamber between the inlet and the outlet (20),
A valve shaft (31) , a seal portion (33) formed in a bulging shape on the valve shaft to open and close the valve seat on the front side, and a pressure receiving portion (34) on the rear side for receiving fluid pressure from the outlet. the valve unit having a (32), the valve shaft and is formed integrally the valve diaphragm mounted in the room on the opposite side of the valve portion (35) poppet valve body (30) which have a and,
Pressure regulating means (40) provided outside the valve chamber of the diaphragm section to constantly regulate the pressure of the poppet valve body in the forward direction and to open the seal section of the valve section by the inflow pressure of the controlled fluid ;
A diameter distance (SD) of the seal portion of the valve portion of the poppet valve body is formed to be larger than a diameter distance (MD) at a position where the maximum diameter and the minimum diameter of the membrane portion of the diaphragm portion are divided into two. Thus, the force acting on the valve portion in the valve body forward direction (X) is greater than the force acting on the membrane portion of the diaphragm portion from the controlled fluid in the valve body retreat direction (Y). check valve structure, characterized in that <br/> you. 2. The check valve structure according to claim 1, wherein the pressure adjusting means comprises a piston formed integrally with the valve shaft, a cylinder portion into which the piston is inserted, and a drive mechanism for adjusting the pressure of the piston. 3. The check valve structure according to claim 2, wherein the drive mechanism for adjusting the pressure of the piston is a spring that constantly biases the piston in the forward direction. The check valve structure according to claim 2 or 3, further comprising a pressure adjusting air mechanism that enables movement and adjustment of a piston of the pressure adjusting means in a forward direction and a backward direction.

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