JP5091926B2 - Resin check valve and fluid equipment unit using the same - Google Patents

Description

  The present invention relates to a resin check valve that is interposed in a pipe and allows a fluid to flow only in one direction, and a fluid device unit that uses the check valve.

  For example, in a cleaning device or an etching device used in a semiconductor manufacturing process, a check valve for preventing a high-purity cleaning solution or a highly corrosive etching solution from flowing back to the supply side may be used. Further, for example, it is disposed at a branch portion of a pure water line for purging the chemical liquid line, and prevents mixing of a plurality of chemical liquids in the pure water line. This type of check valve requires high corrosion resistance and cleanliness, and all parts are made of resin.

FIG. 10 is a cross-sectional view of a conventional resin check valve 100.
As shown in FIG. 10, the resin check valve 100 has a valve body 104 slidably housed in a valve body housing chamber 103 formed between an upstream body 101 and a downstream body 102. The valve body 104 includes a tapered portion 104a whose right end surface in the drawing has a smaller diameter toward the upstream body 101 side, and is biased by a spring 105 that is contracted between the downstream body 102 and the valve body 104. The taper portion 104a is arranged in a state of being inserted into the opening peripheral edge portion 101a of the upstream body 101.

  In the resin check valve 100, when the fluid pressure acting on the valve body 104 from the upstream body 101 side is less than the resultant force of the urging force of the spring 105 and the fluid pressure acting on the valve body 104 from the downstream body 102 side. For this, the outer peripheral surface of the tapered portion 104a is pressed against the opening peripheral portion 101a to close the valve. On the other hand, when the fluid pressure acting on the valve body 104 from the upstream body 101 side becomes larger than the resultant force of the urging force of the spring 105 and the fluid pressure acting on the valve body 104 from the downstream body 102 side, the valve body 104 is moved to the spring 105. The taper portion 104a is moved away from the opening peripheral edge portion 101a against the urging force, and the fluid flows from the upstream body 101 to the downstream body 102 (see, for example, Patent Document 1).

JP 2001-182852 A

  However, the conventional resin check valve 100 performs line sealing by pressing the tapered portion 104a against the edge of the opening peripheral edge portion 101a and closes the valve. For example, when the resin check valve 100 is arranged in series with the automatic valve, repeated pressure generated in the fluid by the valve opening / closing operation of the automatic valve or a high pressure such as a water hammer is generated when the resin check valve 100 is closed. When acting on the valve body 104 from the downstream body 102 side, as shown in FIG. 11, in the valve body 104, the edge of the opening peripheral edge portion 101a bites into the tapered portion 104a, and a step 110 is formed on the outer periphery of the tapered portion 104a. The step 110 was pressed into the opening peripheral edge 101a. In this case, in the resin check valve 100, the fluid pressure from the upstream body 101 side to the valve body 104 is a resultant force of the urging force of the spring 105 and the fluid pressure acting on the valve body 104 from the downstream body 102 side. In addition, if the pressure does not become larger than the pressure input of the step 110, the valve is not opened and the cracking pressure fluctuates. If the pressure setting of the fluid is lower than the cracking pressure after the fluctuation, the fluctuation of the cracking pressure cannot flow the fluid, and causes problems such as cleaning failure and etching failure in semiconductor manufacturing.

  The present invention has been made to solve the above-mentioned problems, and provides a resin check valve capable of obtaining stable sealing performance without fluctuation of cracking pressure and a fluid device unit using the same. The purpose is to do.

The resin check valve according to the present invention and the fluid device unit using the same have the following configuration.
(1) a valve body including a valve body storage chamber communicating with the upstream flow path and the downstream flow path, a valve seat provided in an opening portion where the upstream flow path opens in the valve body storage chamber, A valve body that is housed in the valve body storage chamber and contacts or separates from the valve seat; and a spring that is contracted in the valve body storage chamber and biases the valve body in the valve seat direction, In the resin check valve in which the valve body, the valve seat, the valve body, and the spring are made of resin, the valve seat is on the outer periphery of the opening portion where the upstream flow path of the valve body storage chamber is opened, A valve seat surface constituted by a flat surface provided on a surface orthogonal to the axis of the valve body storage chamber, wherein the valve body protrudes in a ring shape on a surface facing the valve seat surface. The valve seat surface has an annular seal portion provided with a flat surface, and the valve seat surface is made of a material having high hardness after cutting. With member, by finishing by burnishing pressing a jig which is flat finish mirror and plastic deformation of the surface portion at least said annular sealing portion is in contact, is reduced flatness. When the fluid of the repetitive pressure flows back, the flat annular seal portion is brought into contact with the valve seat surface finished by the burnishing process. While the cracking pressure is prevented from fluctuating without being digged into the seat surface, the sealing performance is stabilized even when the spring made of resin having a weak spring force is used when the pressure of the backflowing fluid is low.

( 2 ) In the invention described in (1), at least one of the valve seat and the valve body is made of PTFE.

( 3 ) A fluid device unit having the resin check valve described in (1) or (2) and a fluid device in which the resin check valve is disposed on the downstream side of the flow path, The fluid device includes a flow channel block in which a flow channel is formed, a fixed block fixed to the flow channel block, and a screw that fixes the fixed block to the flow channel block. The upstream body having the upstream flow path and the valve seat surface and the downstream body having the downstream flow path are connected to each other, and the valve body storage chamber is provided between the upstream body and the downstream body. The flow path block has an insertion hole through which the upstream body is integrally formed at the output side opening of the flow path, the screw is inserted, and the valve seat surface is the insertion hole. It is provided outside the hole.

( 4 ) A fluid device unit comprising the resin check valve described in (1) or (2) and a fluid device in which the resin check valve is disposed on the upstream side of the flow path, The fluid device includes a flow channel block in which a flow channel is formed, a fixed block fixed to the flow channel block, and a screw that fixes the fixed block to the flow channel block. The upstream body having the upstream flow path and the valve seat surface and the downstream body having the downstream flow path are connected to each other, and the valve body storage chamber is provided between the upstream body and the downstream body. that are formed over a substrate wherein the flow path block, the downstream body on the input side opening of the flow path is integrally molded, and have a through hole in which the screw is inserted, the valve seat surface is the insertion wherein the are found provided outside the hole.

( 5 ) In the invention described in (3) or (4) , the flow path block has a notch groove between the valve seat surface and the insertion hole.

  In the resin check valve, the valve seat surface plastically deforms at least the surface of the portion where the annular seal portion abuts, and the flatness of the portion where the annular seal portion abuts is reduced. Even when the same resin spring is used, when the valve body is brought into contact with a valve seat surface that has been plastically processed to improve flatness, the valve body is brought into contact with a valve seat surface that is not plastically processed. It has better adhesion and seals with low pressure. Moreover, since the resin check valve seals the flat surface of the annular seal portion in contact with the valve seat surface, the valve body does not bite into the opening peripheral edge of the valve seat surface. Therefore, according to the above-described resin check valve, even when a high pressure such as pressure or water hammer is repeatedly applied from the downstream flow path to the valve body when the valve is closed, the valve body does not deform. The stable sealing performance can be maintained by preventing the fluctuation of the above.

  The above-mentioned check valve made of resin is finished by burnishing after cutting the valve seat surface, and the surface roughness and flatness of the valve seat surface are reduced, so a resin spring that cannot increase the spring force is used. However, the sealing performance can be stabilized by bringing the annular seal portion into close contact with the valve seat surface.

  In the resin check valve, since at least one of the valve main body or the valve body is made of PTFE having low hardness, a member having low hardness is deformed following the unevenness of the counterpart, and the surface between the annular seal portion and the valve seat surface Fill the gap formed in the seal part. Therefore, according to the resin check valve, the adhesion between the annular seal portion and the valve seat surface can be improved, and the sealing performance can be stabilized.

  In the fluid device unit, the upstream body (or downstream body) of the check valve is integrally formed in the downstream opening (or upstream opening) of the flow block, and the check valve is built in the flow block. ing. When assembling a fluid device by fixing the flow path block and the fixing block with screws, the flow path block may be distorted by the fastening force of the screws, and the distortion may act on the valve seat surface and cause the valve seat surface to swell. . However, according to the present invention, since the valve seat surface is provided outside the insertion hole through which the screw is inserted, the fastening force of the screw hardly affects the valve seat surface, and the stable sealing performance can be maintained.

  The fluid device unit releases strain generated in the flow channel block when the screw inserted into the insertion hole of the flow channel block is fastened to a notch groove provided between the valve seat surface and the insertion hole, Since the distortion does not affect the valve seat surface, it is possible to prevent the valve seat surface from wobbling when the flow path device unit is assembled and the sealing performance from being deteriorated.

It is a side view of a fluid equipment unit using a resin check valve according to the first embodiment of the present invention. It is sectional drawing of the resin check valve which concerns on embodiment of this invention. It is an exploded sectional view of a resin check valve. It is a side view of a spring. It is AA sectional drawing of FIG. It is a figure which shows the result of having compared flatness, surface roughness, and sealing pressure according to the processing method of a valve seat surface. It is a graph which shows the relationship between surface roughness and flatness, and an internal sealing force. It is sectional drawing of the fluid apparatus unit which concerns on 2nd Embodiment of this invention. It is sectional drawing of the fluid apparatus unit which concerns on 3rd Embodiment of this invention. It is sectional drawing of the conventional resin check valve. It is a figure which shows a deformation | transformation of a taper part.

  Hereinafter, an embodiment of a resin check valve and a fluid device unit using the resin check valve according to the present invention will be described with reference to the drawings.

<Example of fluid equipment unit>
FIG. 1 is a side view of a fluid device unit 1 using a resin check valve 10 according to an embodiment of the present invention.
The fluid equipment unit 1 connects a fluid control valve 2, a pipe 3, and a resin check valve (hereinafter referred to as “check valve”) 10 via a joint 4 from the upstream side to the downstream side. Backflow to the fluid control valve 2 is prevented.

<Check valve configuration>
FIG. 2 is a cross-sectional view of the check valve 10.
In the check valve 10, all parts are made of resin in order to ensure corrosion resistance. In the check valve 10, an upstream body 12 and a downstream body 13 are integrated by a connecting nut 14 to constitute a valve body 11. A valve body storage chamber 16 is formed inside the valve body 11 so as to communicate with the upstream flow path 12b and the downstream flow path 13b. In the valve body storage chamber 16, a valve seat surface 19 is provided around an opening where the upstream flow path 12 b opens, and a valve body 17 biased by a spring 18 is in contact with the valve seat surface 19. The valve body 17 and the spring 18 are provided with a clearance between the inner wall of the valve body storage chamber 16, and the guide portion 18 f is slidably contacted with the inner wall of the valve body storage chamber 16 during the valve opening / closing operation. The portion 18a is prevented from coming into contact with the spring housing recess 13a to prevent generation of particles. When the internal pressure of the upstream flow path 12b overcomes the resultant force of the urging force of the spring 18 and the internal pressure of the valve body storage chamber 16, the check body 10 moves the valve body 17 toward the downstream flow path 13b. However, the movement amount of the valve element 17 is regulated by applying the guide part 18 f of the spring 18 to the stopper part 22 provided on the inner peripheral surface of the valve element storage chamber 16.

FIG. 3 is an exploded cross-sectional view of the check valve 10.
The upstream body 12 has an upstream joint port 12a, an upstream flow path 12b, and a valve body housing recess 12c provided coaxially to form a flow path. The upstream body 12 has an insertion recess 12d formed coaxially with the valve body storage recess 12c from the left end face in the figure. The valve body housing recess 12c has an inner diameter larger than the maximum outer diameter of the valve body 17 and the spring 18 so that the guide body 18f of the valve body 17 and the spring 18 can reciprocate linearly in the axial direction. The insertion recess 12d has an inner diameter larger than that of the valve body storage recess 12c, and an annular seal groove 12e is coaxial with the valve body storage recess 12c at the step portion between the insertion recess 12d and the valve body storage recess 12c. Is provided.

  The downstream body 13 is provided with a spring housing recess 13a, a downstream flow path 13b, and a downstream joint port 13c on the same axis to form a flow path. An insertion portion 13i that is slidably inserted into the insertion recess 12d is provided on the right end surface of the downstream body 13 in the drawing. The insertion portion 13i has a spring housing recess 13a formed in a cylindrical shape having a smaller diameter than the valve body housing recess 12c from the right end surface in the drawing. The spring accommodating recess 13a accommodates the inner diameter dimension larger than the outer diameter dimension of the coil portion 18a of the spring 18 so that the spring 18 can be expanded and contracted without contact. An annular projection 13d corresponding to the annular seal groove 12e is provided concentrically with the spring housing recess 13a on the right end surface of the insertion portion 13i in the figure, and protrudes in the axial direction. The downstream body 13 is provided with an annular flange portion 13e along the outer peripheral surface for restricting the amount of insertion of the insertion portion 13i into the insertion recess 12d.

  The downstream body 13 is inserted through the connecting nut 14 from the left end in the drawing so that the flange portion 13e is pressed by the pressing portion 14a of the connecting nut 14, and the female screw portion 14b of the connecting nut 14 is formed on the outer peripheral surface of the upstream body 12. It is fastened to the formed connecting male screw portion 12i. When the connecting nut 14 is tightened, the downstream body 13 is pressed toward the upstream body 12 via the flange portion 13e, and the annular protrusion 13d is press-fitted into the annular seal groove 12e to be tightly fitted. Thereby, as shown in FIG. 2, the connection part of the valve body accommodation recessed part 12c and the spring accommodation recessed part 13a is sealed by radial direction, and the airtight valve body accommodation chamber 16 is formed. And the valve body storage chamber 16 is provided with the stopper part 22 by the level | step difference formed between the valve body storage recessed part 12c and the spring storage recessed part 13a.

  As shown in FIGS. 2 and 3, a plurality of pin fixing portions 12 f are formed at equal intervals in the circumferential direction along the outside of the opening of the insertion recess 12 d on the left end surface of the upstream body 12 in the drawing. . The rotation stopper pin 20 is press-fitted and fixed to the pin fixing portion 12f. The downstream body 13 is provided with pin holes 13f corresponding to the pin fixing portions 12f on the end surface of the flange portion 13e facing the upstream body 12. When the connecting nut 14 is tightened, the downstream body 13 is prevented from rotating relative to the upstream body 12 by inserting the rotation prevention pin 20 into the pin hole 13f. Therefore, the downstream body 13 moves only in the axial direction, and presses the annular protrusion 13d into the annular seal groove 12e.

  The upstream body 12 has a pin fixing portion 12g adjacent to the right side of the connecting male screw portion 12i in the drawing. The connection nut 14 is formed with an anti-rotation groove 14c in the axial direction from the end surface opposite to the pressing portion 14a. The rotation stop pin 21 is inserted into the rotation stop groove 14c so as to be slidable. The anti-rotation grooves 14c are provided at equal intervals at a short pitch in the outer peripheral direction of the end face of the connection nut 14 so as to secure the rigidity against the force received in the rotation direction from the anti-rotation pin 21 while facilitating positioning with the pin fixing portion 12g. (See FIG. 1). The rotation prevention pin 21 is fixed by being pushed into the pin fixing portion 12g so as to be engaged with one of the rotation prevention grooves 14c after the connection nut 14 is tightened to a specified position, and the connection nut 14 is fixed to the upstream body 12. On the other hand, it is prevented from rotating and loosening.

  In the downstream body 13, a spring receiving portion 13h is formed coaxially with the spring accommodating recess 13a between the spring accommodating recess 13a and the downstream flow passage 13b. The spring receiving portion 13h is provided so as to be fitted only to the rear end portion 18d of the coil portion 18a of the spring 18, and the spring 18 is positioned, and clearance is provided so that the coil portion 18a does not rub against the spring housing recess portion 13a during expansion and contraction. Keep.

FIG. 4 is a side view of the spring 18. FIG. 5 is a cross-sectional view taken along the line AA in FIG.
The spring 18 is an injection molded product of fluororesin such as PFA. In the spring 18, a rear end surface 18d of the coil portion 18a and a front end surface 18e of the pressing portion 18c are provided at a right angle to the axial direction. As shown in FIGS. 2 and 3, the spring receiving portion 13h is provided with a surface that abuts against the rear end surface 18d of the coil portion 18a at a right angle to the axial direction. Therefore, the spring 18 is disposed coaxially with the valve body storage chamber 16 by attaching the rear end face 18d to the spring receiving portion 13h. The coil portion 18a has an inner diameter dimension that is substantially the same as the inner diameter dimension of the downstream flow path 13b, and the fluid that has flowed from the upstream flow path 12b into the valve body storage chamber 16 into the downstream flow path 13b from the inside of the coil section 18a. It is designed to flow without resistance.

  As shown in FIG. 4, the spring 18 is provided with a pressing portion 18c at one end of the coil portion 18a so that the elastic force of the coil portion 18a acts on the valve body 17 (see FIG. 2) in a planar shape. As shown in FIGS. 4 and 5, a guide portion 18f is fixed to the pressing portion 18c so as to protrude outward. The guide portions 18f are provided at equal intervals along the circumferential direction of the pressing portion 18c, and the fluid flowing out from the valve seat surface 19 easily flows into the coil portion 18a through the guide portions 18f.

  As shown in FIGS. 2 and 3, in the spring 18, the positioning protrusion 17b protruding from the center of the end surface of the valve body 17 is fitted into the holding hole 18b formed in the center of the end surface of the pressing portion 18c without any gap. Thus, the valve body 17 is attached. The valve body 17 is provided in a disk shape having the same diameter as the tip surface 18e of the pressing portion 18c, and comes into surface contact with the tip surface 18e of the pressing portion 18c so that the spring force of the coil portion 18a can be uniformly transmitted. Yes. The valve body 17 is provided with an annular seal portion 17a protruding in the axial direction on the end surface opposite to the end surface provided with the positioning projection 17b. The annular seal portion 17a is provided concentrically with the valve body 17 on substantially the extension of the coil portion 18a so that the elastic force of the coil portion 18a acts directly. The annular seal portion 17a is wide so that the radial width dimension is not deformed even when the load of the spring 18 is received, and the surface facing the valve seat surface 19 is flattened.

  The valve seat surface 19 is provided flat on a step portion between the valve body housing recess 12c of the upstream body 12 and the upstream flow path 12b. In the present embodiment, the material of the upstream body 12 is PFA (tetrafluoroethylene perfluoroalkyl vinyl ether copolymer), and the material of the valve body 17 is PTFE (polytetrafluoroethylene). From the viewpoint of improving the sealing performance, one of the valve seat surface 19 and the valve body 17 may be made of a low-hardness resin (such as PTFE), and the material of the upstream body 12 may be PTFE. The upstream body 12 is provided with a valve body housing recess 12c so that the valve seat surface 19 is a plane perpendicular to the axis of the upstream flow path 12b. Then, a member made of a material harder than the upstream body 12 (for example, SUS) is pressed on the valve seat surface 19 with a jig finished flat with a mirror surface and burnished to form the valve seat surface 19 by drilling. The fine irregularities are crushed and plastically deformed to reduce the surface roughness while maintaining the flatness. Therefore, the flatness and surface roughness of the portion where the annular seal portion 17a abuts on the valve seat surface 19 is improved as compared with the case where the valve seat surface 19 is simply formed by cutting or the like.

<Effects of valve seat surface processing on surface roughness, flatness, and sealing pressure>
The inventor burns the valve seat surface using an upstream body formed by cutting the valve seat surface (hereinafter referred to as “cutting body” in the explanation of the experiment) and a SUS jig flattened with a mirror surface. For the finished upstream body (hereinafter referred to as “polishing body” in the description of the experiment), circumferential flatness (μm), radial flatness (μm), and surface roughness were measured.

The circumferential flatness was measured using a detector rotating roundness measuring machine. In the experiment, the upstream body, which is the object to be measured, is set on the measuring machine, and the measuring element is set at a position where the valve body comes into contact with the valve seat and rotated to measure the flatness of one circumference on the valve seat surface. did.
The radial flatness was measured using a shape measuring machine. In the experiment, the measuring element of the measuring device was moved in the outer diameter direction within the range from the edge portion of the valve seat surface opening to the diameter of the valve seat surface of 11.4 mm, and the flatness in the radial direction was measured.
For the surface roughness, the upstream body was set on the surface roughness meter, and the arithmetic average roughness Ra and the maximum roughness (height difference) Ry of the valve seat surface were measured.

The experimental results are shown in FIG.
As shown in FIG. 6, the circumferential flatness of the cutting body was 21.7 μm, whereas the polishing body was 8.5 μm, and the polishing body had less circumferential waviness than the cutting body. found.
The radial flatness was 12.6 μm for the cutting body, while 5.0 μm for the polishing body, and it was found that the waviness in the radial direction of the polishing body was smaller than that of the cutting body.
The arithmetic average roughness Ra was 0.187 for the cutting body, but 0.091 for the polishing body, and it was found that the polishing body had smaller irregularities on average than the cutting body.
The maximum roughness Ry was 1.387 for the cutting body, but 0.546 for the polishing body, and it was found that the polishing body had a smaller maximum height difference in the unevenness of the valve seat surface than the cutting body.

  From the above experimental results, the body finished the valve seat surface only by cutting by pressing a SUS jig that was flattened with a mirror surface against the valve seat surface that had been flattened by cutting and burnishing. It was found that the flatness and surface roughness improved. This is because minute unevenness formed on the valve seat surface during cutting is crushed and flattened by the jig, and the height difference between the peak and valley is reduced.

<Effects of valve seat surface processing on sealing pressure>
The inventor conducted an experiment to examine the influence of the processing of the valve seat surface on the sealing pressure. The sealing pressure refers to a pressure that can prevent fluid leakage when pressure is applied downstream. In the experiment, with the valve body 17 in contact with the valve seat surface of the upstream body, pressure was applied to the downstream side of the valve body (opposite to the upstream flow path 12b) to check for fluid leakage. . In this experiment, the pressure for pressing the valve element 17 against the valve seat surface was gradually increased, the minimum value of pressure that could prevent fluid leakage was obtained, and the minimum value was taken as the sealing pressure. The experimental results are shown in FIG.

  As shown in FIG. 6, the cutting body had a sealing pressure of 0.083 MPa, whereas the polishing body had a sealing pressure of 0.048 MPa. Therefore, the check valve using the polishing body is a spring 18 having a smaller spring force than the check valve using the cutting body, and prevents the valve element 17 from leaking fluid against the pressure acting from the downstream side. Can do. In other words, if the spring force is the same, it can be said that the margin for the seal is improved. This is because the valve seat surface 19 of the polishing body is small in flatness and surface roughness, so that the clearance between the annular seal portion 17a of the valve body 17 is smaller than the valve seat surface flattened only by cutting, and the fluid flows. It is considered that it is difficult to enter between the annular seal portion 17a and the valve seat surface 19, and the seal surface pressure (stress necessary for sealing) is reduced.

<Relationship between flatness and surface roughness and sealing pressure>
The inventor conducted an experiment to examine which of flatness and surface roughness increases the sealing pressure. In the experiment, the sealing pressure was measured in the same procedure as above for five types of polishing bodies having different surface roughness and circumferential flatness. The experimental results are shown in FIG. In FIG. 7, the vertical axis represents the sealing pressure (MPa), and the horizontal axis represents the circumferential flatness (μm) and surface roughness (μm).

  As shown by the black squares (■) in FIG. 7, the circumferential flatness has a proportional relationship with the sealing pressure in the range of 2 μm to 22 μm. On the other hand, as shown by the black circles (●) in the figure, the surface roughness varies in sealing pressure around 1 μm, and no proportional relationship is recognized between the surface roughness and the sealing pressure. Therefore, it has been found that it is more effective to reduce the circumferential flatness than the surface roughness in order to reduce the sealing pressure. This is considered to be because the valve body 17 is brought into contact with the valve seat surface 19 in a planar shape, and if the swell of the valve seat surface 19 is small, the fluid hardly enters between the valve body 17 and the valve seat surface 19. .

<Description of operation>
In the fluid device unit 1, the fluid is not supplied from the pipe 3 to the check valve 10 when the fluid control valve 2 is closed. In this case, the check valve 10 seals the valve body 17 to the valve seat surface 19 in a planar shape by the urging force of the spring 18, and blocks the flow path between the upstream flow path 12b and the downstream flow path 13b. ing. Therefore, the fluid does not flow backward from the downstream channel 13b to the fluid control valve 2 side.

  When the fluid control valve 2 is opened, fluid is supplied from the pipe 3 to the check valve 10. The check valve 10 is closed when the internal pressure of the upstream flow path 12b is equal to or less than the resultant force of the urging force of the spring 18 and the internal pressure of the valve body storage chamber 16, thereby blocking the flow path. However, when the internal pressure of the upstream flow path 12b exceeds the resultant force of the biasing force of the spring 18 and the internal pressure of the valve body storage chamber 16, the valve body 17 resists the biasing force of the spring 18 and the downstream flow path 13b side. The fluid flows into the valve body storage chamber 16 from the valve seat surface 19. Then, the fluid flows into the coil portion 18a from between the guide portions 18f and flows to the downstream side flow path 13b. At this time, since the coil part 18a moves in the spring housing recess 13a in a non-contact manner, no particles are generated.

  After that, when the fluid control valve 2 is closed, the fluid is not supplied to the check valve 10, so that the check valve 10 expands as the pressure of the upstream flow path 12 b decreases and the check valve 10 expands. The portion 17a is pressed against the valve seat surface 19 to seal it in a planar shape, thereby blocking the flow path. For example, even if a pulsation occurs in the internal pressure of the downstream flow path 13b due to the opening and closing operation of the valve disposed on the downstream side of the check valve 10, the check valve 10 is closed and the pulsation is transmitted to the fluid control valve 2 side. I won't let you. Therefore, the fluid control valve 2 can perform the valve opening operation without being affected by the pressure fluctuation generated on the downstream side of the check valve 10 and can prevent the durability of the fluid control valve 2 from being lowered.

  Here, the valve body 17 is restricted in movement to the upstream flow path 12b side by bringing the annular seal portion 17a into surface contact with the valve seat surface 19, so that the stress is small and is not easily deformed. Therefore, even if the fluid control valve 2 repeats the valve opening / closing operation thousands or tens of thousands of times, the check valve 10 keeps the annular seal portion 17a in contact with the valve seat surface 19 in a planar shape, thereby providing a stable seal. Performance can be maintained.

<Effect>
Therefore, in the check valve 10 of the present embodiment, the valve seat surface 19 is plastically deformed by crushing minute irregularities formed on at least the surface of the portion where the annular seal portion 17a abuts, and the annular seal portion 17a is applied. The flatness of the contacting part is reduced. Even when the same resin spring 18 is used, when the annular seal portion 17a is brought into contact with the valve seat surface 19 improved in flatness by plastic processing, the annular seal portion is applied to the valve seat surface not plastically processed. The close contact between the annular seal portion 17a and the valve seat surface 19 is better than when the 17a is brought into contact, and the fluid enters the gap between the annular seal portion 17a and the valve seat surface 19 so that the valve element 17 is not easily moved. Moreover, since the check valve 10 seals the flat surface of the annular seal portion 17a by contacting the valve seat surface 19, the valve body 17 does not bite into the opening peripheral portion of the valve seat surface 19 as in the prior art. . Therefore, according to the check valve 10 of the present embodiment, the valve body 17 can be deformed even when a high pressure such as a pressure or a water hammer is repeatedly applied to the valve body 17 from the downstream flow path 13b when the valve is closed. Therefore, the fluctuation of cracking pressure can be prevented and stable sealing performance can be maintained.

  The check valve 10 of the present embodiment is finished by burnishing after the valve seat surface 19 is cut, and the surface roughness and flatness of the valve seat surface 19 are reduced. Even when the spring 18 is used, the sealing performance can be stabilized by bringing the annular seal portion 17a into close contact with the valve seat surface 19.

  In the check valve 10 of the present embodiment, the PTFE valve element 17 having a low hardness is deformed following the unevenness of the valve seat surface 19 made of PFA having a high hardness, and the annular seal portion 17a and the valve seat surface 19 are deformed. The gap formed in the face seal portion is filled. Therefore, according to the check valve 10, it is possible to improve the adhesion between the annular seal portion 17a and the valve seat surface 19 and to stabilize the sealing performance.

  In the check valve 10 of the present embodiment, the flat surface of the annular seal portion 17a is sealed to the valve seat surface 19, and since an O-ring is not used, components do not deteriorate when flowing corrosive fluid. Difficult to contaminate fluid.

  In the check valve 1 of the present embodiment, the rotation prevention pin 21 is press-fitted and fixed to the pin fixing portion 12g from the rotation prevention groove 14c, so that it is possible to prevent the connecting nut 14 from loosening and disassembling after assembly. .

  The fluid device unit 1 using the resin check valve 10 of the present embodiment prevents the downstream body 13 from rotating relative to the upstream body 12 by the rotation prevention pin 20 when the connection nut 14 is tightened. Since the annular protrusion 13d is moved only in the axial direction and press-fitted into the annular seal groove 12e, the valve body storage chamber 16 can be reliably kept airtight. Moreover, in order not to rotate the upstream body 12 and the downstream body 13 relatively, it is easy to perform a pipe construction work for connecting the check valve 10 to the pipe 3.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 8 is a cross-sectional view of a fluid device unit 31 according to the second embodiment of the present invention.
The fluid device unit 31 of the second embodiment is a fluid device unit using the resin check valve 10 of the first embodiment in that a check valve is built in a joint portion of the fluid device to reduce the foot space. 1 and different. Therefore, here, it demonstrates centering on a different point from 1st Embodiment, the point which is common in 1st Embodiment describes the same code | symbol as 1st Embodiment in drawing, and abbreviate | omits description suitably.

  The fluid device unit 31 is provided with the check valve 36 integrally with the fluid control valve 32, and the operation thereof is the same as that of the fluid device unit 1 using the resin check valve 10 of the first embodiment. . The fluid control valve 32 is configured by stacking a drive unit (an example of a fixed block) 34, a flow path block 33, and a mounting plate 37 and fixing them with screws 35. In the fluid control valve 32, except for a spring built in the drive unit 34, each component is made of resin in order to ensure corrosion resistance. The fluid control valve 32 controls the fluid flowing through the first flow path 33a and the second flow path 33b of the flow path block 33 by causing the drive unit 34 to contact or separate a valve body (not shown) from a valve seat (not shown). .

  The flow path block 33 is obtained by cutting and molding a fluororesin (PTFE in this embodiment). The flow path block 33 includes an upstream body 33c at the opening of the second flow path 33b. The upstream body 33 c corresponds to the upstream body 12 of the first embodiment, and is integrally formed with the flow path block 33. The valve seat surface 19 of the upstream body 33c is also flattened by cutting, and then pressed with a SUS jig finished flat with a mirror surface and burnished to reduce flatness and surface roughness. Yes. In the flow path block 33, the valve seat surface 19 is provided outside the insertion hole 33e through which the screw 35 is inserted, and a notch groove 33d is formed annularly between the valve seat surface 19 and the insertion hole 33e.

  In the fluid device unit 31, the upstream body 33 c of the check valve 36 is integrally formed in the opening of the second flow path 33 b of the flow path block 33, and the check valve 36 is built in the flow path block 33. . When the fluid control valve 32 is assembled by fixing the flow path block 33 and the drive unit 34 with the screw 35, the flow path block 33 is distorted by the fastening force of the screw 35, and the distortion acts on the valve seat surface 19 to cause the valve. There is a possibility that the seat surface 19 may swell. However, in the fluid device unit 31 using the resin check valve 36, the valve seat surface 19 is provided outside the insertion hole 33 e through which the screw 35 is inserted, so that the fastening force of the screw 35 is applied to the valve seat surface 19. It is less affected and can maintain stable sealing performance.

  The fluid device unit 31 has a notch groove provided between the valve seat surface 19 and the insertion hole 33e for distortion generated in the flow path block 33 when the screw 35 inserted into the insertion hole 33e of the flow path block 33 is fastened. 33d, and the distortion of the flow path block 33 is prevented from affecting the valve seat surface 19. Therefore, it is possible to prevent the valve seat surface 19 from swelling and lowering the sealing performance when the flow path device unit is assembled.

  In such a fluid device unit 31, the upstream body of the check valve 36 is formed integrally with the flow channel block 33, and the check valve 36 is built in the flow channel block 33, so the fluid device of the first embodiment. The foot space can be reduced by omitting the pipe 3 portion of the unit 1.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to the drawings. FIG. 9 is a sectional view of a fluid device unit 41 according to the third embodiment of the present invention.
The fluid device unit 41 of the second embodiment is a fluid device unit using the resin check valve 36 of the second embodiment in that the downstream body 43a of the check valve 44 is integrally formed with the flow path block 43. 31. Therefore, here, it demonstrates focusing on the point which is different from 2nd Embodiment, and the point which is common in 2nd Embodiment describes the same code | symbol as 2nd Embodiment in drawing, and abbreviate | omits description suitably.

  In the fluid device unit 41, the downstream body 43 a is integrally provided at the opening of the first flow path 33 a of the flow path block 43. The downstream body 43a corresponds to the downstream body 13 of the check valve 10 of the first embodiment, but the connection structure with the upstream body 45 is the reverse of that of the first embodiment.

  Specifically, in the flow path block 43, an insertion recess 43b for inserting the upstream body 45 is provided in the opening of the spring storage recess 13a, and an annular seal is formed at the step portion between the spring storage recess 13a and the insertion recess 43b. A groove 43c is formed. On the outer periphery of the downstream body 43a, a connecting male screw portion 43d to which the connecting nut 14 is screwed is formed, and on the left side of the connecting male screw portion 43d in the drawing, a pin fixing portion to which the rotation-preventing pin 21 is press-fitted and fixed. 43f is formed. A plurality of rotation-preventing pins 20 for preventing the upstream body 45 from rotating with respect to the flow path block 43 when the connecting nut 14 is fastened are press-fitted and fixed to the right end surface in the drawing of the downstream body 43a. Are fixed evenly in the circumferential direction outside the opening of the insertion recess 43b.

  On the other hand, the upstream body 45 includes an insertion portion 45a to be inserted into the insertion recess 43b, and the valve body housing recess 12c is opened at the end surface of the insertion portion 45a. An annular projection 45b is provided on the end surface of the insertion portion 45a along the outer periphery of the opening of the valve body housing recess 12c. The annular projection 45b is press-fitted into the annular seal groove 43c for sealing. Further, a flange portion 45c projects from the outer peripheral surface of the upstream body 45, and the connection nut 14 is engaged so as not to be detached. An anti-rotation groove 45d is formed on the left end surface of the flange portion 45c in the drawing so as to correspond to the pin fixing portion 43e.

  In such a fluid device unit 41, the rotation-preventing pin 20 is press-fitted and fixed to the pin fixing portion 43e, and the spring 18 having the valve element 17 attached thereto is set to the spring receiving portion 13h of the flow path block 43. Then, the upstream body 45 is inserted into the connecting nut 14 so as to press the flange portion 45c with the pressing portion 14a. Then, with the rotation-preventing pin 20 inserted into the rotation-preventing groove 45d, the connecting nut 14 is tightened into the connecting male screw portion 43d, and the upstream body 45 is moved toward the flow path block 43 along the axis. At this time, the annular protrusion 45b is inserted into the annular seal groove 43c, and the connecting portion between the valve body housing recess 12c and the spring housing recess 13a is sealed in the radial direction. Thereby, the check valve 44 is built in the fluid control valve 42.

  In the fluid device unit 41, the downstream body 43 a of the check valve 44 is integrally formed in the opening of the first flow path 33 a of the flow path block 43, and the check valve 44 is built in the flow path block 43. When the fluid control valve 42 is assembled by fixing the flow path block 43 and the drive unit 34 with the screw 35, the flow path block 43 is distorted by the fastening force of the screw 35, and the distortion acts on the valve seat surface 19 to cause the valve There is a possibility that the seat surface 19 may swell. However, in the fluid device unit 41 using the resin check valve 44, the valve seat surface 19 is provided outside the insertion hole 33 e through which the screw 35 is inserted, so that the fastening force of the screw 35 is applied to the valve seat surface 19. It is less affected and can maintain stable sealing performance.

  Further, the fluid device unit 41 using the resin check valve 44 has the check valve 44 built in the flow path block 43, so that the foot space can be reduced by omitting the pipe 3 portion.

In addition, this invention is not limited to the said embodiment, Various application is possible.
For example, in the above embodiment, the upstream body 12 is made of a fluororesin (PFA or the like) having a hardness higher than that of the valve body 17, but the upstream body 12 may be made of a fluororesin (PTFE or the like) having the same hardness as the valve body 17. . Even in this case, the valve body 17 is easily deformed following the unevenness of the valve seat surface 19, and the annular seal portion 17 a can be satisfactorily adhered to the valve seat surface 19.
For example, in the said embodiment, the fluid control valves 32 and 42 were mentioned as an example of the fluid apparatus. On the other hand, a check valve may be incorporated in a flow path block of a fluid device such as a pressure gauge, a flow meter, a mass flow controller, or a regulator.

2, 32, 42 Fluid control valve (an example of fluid equipment)
10, 36, 44 Check valve 12, 45 Upstream body 12b Upstream passage 13 Downstream body 13b Downstream passage 16 Valve body storage chamber 17 Valve body 17a Annular seal 18 Spring 19 Valve seat surface 31, 41 Fluid Equipment Unit 33c Upstream Body 33d Notch Groove 33e Insertion Hole 34 Drive Unit (Example of Fixed Block)
35 screws

Claims (5)

A valve body having a valve body storage chamber communicating with the upstream flow path and the downstream flow path; a valve seat provided in an opening portion where the upstream flow path opens into the valve body storage chamber; and the valve body storage A valve body that is housed in a chamber and contacts or separates from the valve seat; and a spring that is contracted in the valve body housing chamber and biases the valve body in the valve seat direction; In the resin check valve in which the valve seat, the valve body, and the spring are made of resin,
The valve seat is constituted by a flat surface provided on a surface orthogonal to the axis of the valve body storage chamber on the outer periphery of the opening portion where the upstream flow path of the valve body storage chamber opens. Surface,
The valve body has an annular seal portion that is annularly projected on a surface facing the valve seat surface, and a surface that contacts the valve seat surface is provided flat.
The valve seat surface is finished by a burnishing process that presses a jig finished flat on a mirror surface using a member having a high hardness after cutting, so that at least the surface of the portion where the annular seal portion abuts is formed. Plastic deformation and reduced flatness ,
When the fluid of the repetitive pressure flows back, the flat annular seal portion is brought into contact with the valve seat surface finished by the burnishing process. Prevents cracking pressure fluctuations without biting into the seating surface, and stabilizes sealing performance even when using a spring made of resin with weak spring force when the backflowing fluid pressure is low. A check valve made of resin. In the resin check valve according to claim 1 ,
A resin check valve, wherein at least one of the valve seat and the valve body is made of PTFE. A fluid device unit comprising: the resin check valve according to claim 1 or 2 ; and a fluid device in which the resin check valve is disposed on the downstream side of the flow path,
The fluid device includes a flow channel block in which a flow channel is formed, a fixed block fixed to the flow channel block, and a screw that fixes the fixed block to the flow channel block.
The valve body connects the upstream body having the upstream flow path and the valve seat surface, and the downstream body having the downstream flow path, and between the upstream body and the downstream body. The valve body storage chamber is formed;
The flow path block has the upstream body integrally formed at the output side opening of the flow path, has an insertion hole through which the screw is inserted, and the valve seat surface is provided outside the insertion hole. A fluid device unit characterized by comprising: A fluid device unit comprising: the resin check valve according to claim 1 or 2 ; and a fluid device in which the resin check valve is disposed on the upstream side of the flow path,
The fluid device includes a flow channel block in which a flow channel is formed, a fixed block fixed to the flow channel block, and a screw that fixes the fixed block to the flow channel block.
The valve body connects the upstream body having the upstream flow path and the valve seat surface, and the downstream body having the downstream flow path, and between the upstream body and the downstream body. The valve body storage chamber is formed;
The flow path block, the downstream body on the input side opening of the flow path is integrally molded, and have a through hole in which the screw is inserted, the valve seat surface Re et provided outside than the through hole A fluid equipment unit characterized by comprising: In the fluid equipment unit according to claim 3 or 4 ,
The fluid passage unit, wherein the flow path block has a notch groove between the valve seat surface and the insertion hole.

Images