JP6681723B2 - Valve device - Google Patents

Description

  The present invention relates to a valve device that moves a valve element in a vertical direction with respect to a valve seat to bring the valve element into and out of contact with the valve seat.

  Conventionally, in various industries such as chemical factories, agriculture / fisheries, semiconductor manufacturing fields, liquid crystal manufacturing fields, and food fields, the valve body is moved vertically toward and away from the valve seat to open and close the flow path. A valve device is used. As such a valve device, for example, there is a diaphragm valve described in Patent Document 1.

  In a diaphragm valve, a valve seat is generally formed around the opening from the flow passage to the valve chamber in the valve body, and the valve body is supported by a diaphragm whose outer edge is fixed to the valve body. By driving the stem connected to the valve body by the drive unit, the valve body is moved in a direction perpendicular to the valve seat, and the valve body is brought into contact with and separated from the valve seat to open and close. Further, in order to enhance the sealing property between the valve body and the valve seat, as in the valve device (diaphragm valve) disclosed in Patent Document 1, a bottom end of the valve body facing the valve seat has a tip with a semicircular cross section. The contact area is reduced by providing a lined contact between the valve body and the valve seat so that a large surface pressure can be obtained between the valve seat and the valve body even under the action of a relatively small pressing force. It is common to

JP, 2008-291911, A JP, 2012-26476, A

  In the field where high cleanliness is required, particles generated in the valve device may be a problem. For example, in the manufacturing process of a semiconductor wafer, contaminants such as particles and various metals and polymer compounds are generated, and if they remain or adhere to the semiconductor wafer, the quality is greatly affected. Therefore, in the semiconductor wafer manufacturing process, the semiconductor wafer is cleaned using the cleaning liquid. However, like the valve device described in Patent Document 1, when an annular rib having a semicircular cross-section tip is provided in the bottom surface region of the valve body that contacts the valve seat, the valve body contacts the valve seat. Since the force per unit area that acts sometimes becomes large, the ribs may be deformed or rubbed to generate particles. When the cleaning liquid containing such particles is discharged from the valve device and used for cleaning the semiconductor wafer, sufficient cleaning is not performed, and the cleanliness of the semiconductor wafer deteriorates.

  In order to suppress the generation of particles due to such contact between the valve body and the valve seat, for example, as described in Patent Document 2, a flat surface is provided on each of the valve seat and the valve body, and the valve seat and the valve body are provided. A method of making surface contact with and is also proposed. When the valve seat and the valve body are brought into surface contact with each other in this way, the impact at the time of collision is received by the surface, the impact is easily absorbed, and the generation of particles can be suppressed. However, in the valve device having the structure in which the valve seat and the valve body are in surface contact as described in Patent Document 2, compared with the valve device in which the valve seat and the valve body are in line contact as described in Patent Document 1. Then, under the action of the same pressing force, the pressure per unit area at the time of contact decreases, and the sealing property deteriorates. Therefore, in order to ensure the same sealing performance as in the case of line contact, it is necessary to increase the thrust of the drive unit in order to increase the pressing force of the valve body against the valve seat. However, when the thrust of the drive unit is increased, the impact at the time of contact between the valve seat and the valve body is increased, the valve seat and the valve body are easily deformed, and particles are easily generated. Further, if the thrust of the valve element is increased, there is a problem in that the drive unit is increased in size.

  Therefore, an object of the present invention is to solve the problems existing in the prior art, and to provide a valve device capable of suppressing the generation of particles when the valve body is seated on the valve seat and also suppressing the deterioration of the sealing property. Especially.

  In view of the above object, the present invention provides a valve body having a valve chamber and a first flow passage and a second flow passage communicating with the valve chamber, and an opening from the first flow passage to the valve chamber. A valve device having an annular valve seat formed around the valve seat and a valve body that is moved in the vertical direction with respect to the valve seat by a drive unit and is brought into contact with and separated from the valve seat, wherein the valve seat and the valve body On the one hand, a flat annular surface and a convex abutting curved surface extending in a convex shape from one of the inner peripheral side and the outer peripheral side of the annular surface in a direction away from the other of the valve seat and the valve body, A flat abutment surface is formed on the other of the valve seat and the valve body so as to face the annular surface, and when the valve body abuts the valve seat, the annular surface contacts the abutment surface. After the surface contact with the contact surface, the convex contact curved surface and the contact surface are deformed by deformation of at least one of the valve seat and the valve body. Providing a valve device which is adapted to shift to the contact.

  In the above valve device, when the valve body is seated on the valve seat, first, the annular surface formed on one of the valve seat and the valve body comes into surface contact with the contact surface formed on the other of the valve seat and the valve body. After that, due to the deformation of the valve seat or the valve body, the convex contact curved surface adjacent to the annular surface comes into line contact with the contact surface. For this reason, under the condition that the pressing force of the valve body against the valve seat is the same, immediately after the seating of the valve body and the valve seat, the contact area becomes wider due to the surface contact, and the pressing force per unit area decreases. The impact when sitting is reduced. Further, after the surface contact, the contact area is changed to the line contact, so that the contact area is narrowed, the pressing force per unit area is increased, and the adhesion between the valve seat and the valve body is improved.

  In the above valve device, it is preferable that the convex contact curved surface is formed such that a tangent plane at a boundary between the annular surface and the convex contact curved surface extends parallel to the annular surface. As a result, the transition between the annular surface and the convex abutting curved surface adjacent thereto becomes smooth, and the edge is not formed at the boundary between the annular surface and the convex abutting curved surface. Occurrence can be prevented or suppressed.

  Further, it is preferable that one of the valve seat and the valve body is provided with an annular rib protruding toward the other, and the annular surface is formed on the top of the rib.

  In this case, on the side surface of the rib on the side opposite to the convex contact curved surface with the annular surface sandwiched, there is a convex auxiliary curved surface extending in a convex shape from the annular surface in a direction away from the annular surface. It is preferable that the convex auxiliary curved surface is formed so that a tangent plane at a boundary between the annular surface and the convex auxiliary curved surface extends parallel to the annular surface. . The formation of the convex auxiliary curved surface has the effect of reducing the impact when the valve body is seated on the valve seat, and the annular surface is the tangent plane of the convex auxiliary curved surface at the boundary with the convex auxiliary curved surface. By forming them so that they are parallel to each other, no edge is formed at the boundary, and it is possible to suppress the generation of particles due to the scraping of the edge when sitting.

  Moreover, it is preferable that the radius of curvature of the convex contact curved surface is larger than the radius of curvature of the convex auxiliary curved surface.

  In one embodiment, the rib is formed on a bottom surface of the valve body facing the valve seat.

  In this case, the bottom surface of the valve body may be a flat surface, and the side surface of the rib and the flat surface may be connected by a concave curved surface.

  Further, the valve body may be connected to a connection end provided at a tip of a stem driven by the drive unit. In this case, the annular surface has an annular shape, the convex contact curved surface is formed on the inner peripheral side surface of the rib, and the outer diameter of the connecting end of the stem is the annular shape. The annular surface is preferably formed so as to be smaller than the inner diameter of the surface. Further, it is preferable that the valve body is connected to the connection end by press-fitting the connection end of the stem into the valve body.

  As one embodiment, the valve device may further include a diaphragm extending radially outward from the periphery of the front valve body, and the valve body may be supported by the valve body via the diaphragm. it can.

  Further, the drive unit may be, for example, an air drive type or a spring drive type.

  According to the valve device of the present invention, when the valve body is seated on the valve seat, it first comes into surface contact and then into line contact. Therefore, at the time of surface contact, the impact at the time of sitting is reduced, and at the time of line contact after the surface contact, the pressing force per unit area becomes high. Therefore, while suppressing the generation of particles when the valve body is seated on the valve seat, it becomes possible to secure a high sealing property between the valve seat and the valve body thereafter.

It is a longitudinal cross-sectional view showing a closed state of the diaphragm valve which is the first embodiment of the valve device of the present invention. FIG. 2 is a vertical sectional view showing an open state of the diaphragm valve shown in FIG. 1. FIG. 2 is an enlarged cross-sectional view of a main part showing a state in which a valve body is seated on a valve seat in the diaphragm valve shown in FIG. It is a partial expanded sectional view which expands and shows the rib of the valve body of the diaphragm valve shown in FIG. 2A and 2B are explanatory views of deformation of the valve element of the diaphragm valve shown in FIG. 1 when seated, in which FIG. 1A shows a state immediately after the valve element is seated on the valve seat, and FIG. The body is deformed. FIG. 2A is an explanatory view of a change in abutment state between a rib of a valve body and a valve seat of the diaphragm valve shown in FIG. 1, and FIG. 3A shows a state of surface contact immediately after the valve body is seated on the valve seat. (B) shows the state of line contact after the valve body is seated on the valve seat and the valve body is deformed. It is a principal part expanded sectional view which shows 2nd Embodiment of the valve apparatus of this invention, (a) has shown the state of surface contact immediately after a valve body seated on a valve seat, (b) shows a valve body. Shows the state of line contact after seated on the valve seat and the valve body is deformed. It is a principal part expanded sectional view which shows 3rd Embodiment of the valve device of this invention, (a) has shown the state of surface contact immediately after the valve body was seated on the rib of a valve seat, (b) shows. It shows a state of line contact after the valve body is seated on the rib of the valve seat and the rib is deformed. It is a principal part expanded sectional view which shows 4th Embodiment of the valve device of this invention, (a) has shown the state of surface contact immediately after a valve body seated on a valve seat, (b) shows a valve body. Shows the state of line contact after seated on the valve seat and the valve body is deformed. It is a principal part expanded sectional view which shows 5th Embodiment of the valve apparatus of this invention, (a) has shown the state of surface contact immediately after a valve body seated on a valve seat, (b) shows a valve body. Shows the state of line contact after seated on the valve seat and the valve body is deformed.

Hereinafter, embodiments of a valve device according to the present invention will be described with reference to the drawings.
First, with reference to FIGS. 1 and 2, the overall configuration of a diaphragm valve 11, which is a first embodiment of a valve device, will be described.

  The diaphragm valve 11 includes a valve body 13, a valve body 15, and a drive unit 17 for driving the valve body 15, and the drive unit 17 is attached to the upper portion of the valve body 13.

  A valve chamber 19 is formed in the center of the upper part of the valve body 13, and a first channel and a second channel communicating with the valve chamber 19 are also formed. An annular valve seat 21 for contacting and separating the valve body 15 is formed around the opening to 19 by cutting. In the illustrated embodiment, an inflow passage 25 extending from an inflow port 23 formed on one side surface of the valve body 13 and opening to the center of the bottom of the valve chamber 19 is formed as the first flow path. As the second flow path, an outflow path 29 extending from the outflow port 27 formed on the other side surface of the valve body 13 and opening to the side surface of the valve chamber 21 is formed. An annular valve seat 21 is formed around the opening.

  The valve body 15 has a weight shape in which the upper end is tapered like a circular truncated cone is connected, and is supported by the valve body 13 so that the bottom surface faces the valve seat 21. .

  The drive unit 17 is housed in the cylinder unit, which is attached to the upper part of the valve body 13 and in which a space for the cylinder unit is formed, a lid member 33 attached to the upper part of the cylinder body 31. A piston 35 and a compression coil spring 37 as a biasing member are provided.

  The piston 35 includes a piston body 35a slidably accommodated in the cylinder portion of the cylinder body 31, a guide shaft 35b extending upward from the upper surface of the piston body 35a, and a stem 35c extending downward from the lower surface of the piston body 35a. Have An outer peripheral surface of the piston body 35a is slidably in contact with an inner peripheral surface of the cylinder portion in the up-down direction, and an inner space of the cylinder portion is defined by an upper surface of the piston body 35a, an inner peripheral wall of the cylinder portion, and a ceiling of the cylinder portion. An upper space 39 surrounded by a surface (that is, a lower surface of the lid member 33), a lower space 41 surrounded by a lower surface of the piston body 35a, an inner peripheral wall of the cylinder portion, and a bottom surface of the cylinder portion (that is, a bottom portion of the cylinder body 31). It is divided into and. The guide shaft 35b is slidably inserted into a through hole provided through the lid member 33, and guides the vertical movement of the piston 35. The stem 35c is slidably inserted into a through hole provided through the bottom of the cylinder body 31, extends to the valve chamber 19, and the valve body 15 is connected to a connecting end 35d located at the tip thereof. ing.

  In the present embodiment, a connecting portion 35d of the stem 35c is provided with an enlarged locking portion, and a complementary connecting hole 15a provided in the valve body 15 is provided with a connecting end (locking portion) 35d of the stem 35c. The valve body 15 is connected to the connection end 35d of the stem 35c by press-fitting. However, the connection of the valve body 15 to the connection end 35d of the stem 35c is not limited to press fitting, and for example, a male screw portion is provided on the outer peripheral surface of the connection end 35d of the stem 35c and the connection hole 15a of the valve body 15 is formed. A female screw portion may be provided on the inner peripheral surface, and the valve body 15 may be connected to the connection end 35d of the stem 35c by screwing.

  The lid member 33 is formed with a ventilation port 43 communicating with the ceiling surface of the cylinder section that defines the upper space 39, and allows ventilation between the upper space 39 and the outside through the ventilation port 43. In addition, a working fluid supply port 45 that communicates with the bottom surface of the cylinder section that defines the lower space 41 is formed on the side of the cylinder body 31, and the working fluid supply port 45 operates into the lower space 41. Can supply fluid. Further, annular grooves 47 and 49 functioning as spring seats are formed on the outer peripheral portion of the upper surface of the piston body 35a and the lower surface of the lid member 33 (the outer peripheral portion of the ceiling surface of the cylinder portion), and both end portions are formed. Inserted in the annular grooves 47, 49, the compression coil spring 37 is arranged between the lower surface of the lid member 33 (the ceiling surface of the cylinder portion) and the upper surface of the piston body 35a.

  The drive unit 17 is attached to the valve body 13 so that the guide shaft 35b of the piston 35 and the stem 35c are perpendicular to the valve seat surface. Further, O-rings 51 and 53 are attached to the outer peripheral surface of the piston main body 35a and the outer peripheral surface of the stem 35c inserted into the through hole at the bottom of the cylinder main body 31, respectively. Between the outer peripheral surface of the stem 35c and the inner peripheral surface of the through hole of the bottom portion (bottom surface of the cylinder portion) of the cylinder body 31 to prevent the working fluid supplied to the lower space 41 from leaking. There is.

  With such a configuration, the piston body 35a is normally urged downward by the compression coil spring 37 and pushed down, and the valve body 15 connected to the piston body 35a via the stem 35c is pressed against the valve seat 21. It As a result, the inflow passage 25 is closed, and the diaphragm valve 11 is closed as shown in FIG. When a working fluid (for example, compressed air) is supplied to the working fluid supply port 45 from this state, the working fluid flows into the lower space 41 of the cylinder portion, an upward fluid pressure acts on the piston body 35a, and the piston body 35a moves. It is pushed up against the biasing force of the compression coil spring 37. At this time, the air in the upper space 39 of the cylinder portion is discharged to the outside from the ventilation passage 43. When the piston main body 35 a moves upward, the valve body 15 connected to the piston main body 35 a via the stem 35 c moves upward and separates from the valve seat 21. As a result, the inflow passage 25 is opened, and the diaphragm valve 11 is opened, as shown in FIG. In the open state, the fluid flowing from the inflow port 23 of the diaphragm valve 11 into the inflow passage 25 flows out from the outflow port 27 through the valve chamber 19 and the outflow passage 29.

  In the diaphragm valve 11, the diaphragm 55 extends radially outward from the outer peripheral portion of the upper end of the valve body 15, and the valve body 15 is supported by the valve body 13 via the diaphragm 55. More specifically, as shown in detail in FIG. 3, an annular horizontal support portion 55a, which is located at the outermost edge portion and extends in the horizontal direction, is provided on the outer peripheral edge portion of the diaphragm 55 and inside the horizontal support portion 55a. And an annular vertical support portion 55b which is vertically located and extends in the vertical direction (vertical direction), and the protrusion 31a extending from the center of the bottom of the cylinder body 31 is inserted into the upper opening of the valve chamber 19 of the valve body 13. At this time, the horizontal support portion 55a is sandwiched between the bottom surface of the cylinder body 31 located outside the protruding portion 31a and the top surface of the peripheral region of the upper opening of the valve chamber 19 of the valve body 13 and the cylinder body 31 By sandwiching the vertical support portion 55b between the outer peripheral surface of the protruding portion 31a and the inner peripheral surface of the upper portion of the valve chamber 19 of the valve body 13, the diaphragm 55 is fixed to the valve body 13. That. An annular groove 55c having a trapezoidal cross section is provided on the bottom surface of the horizontal support portion 55a, and an annular protrusion 55d having a semicircular cross section is provided on the outer surface of the vertical support portion 55b, while the valve of the valve body 13 is provided. An annular projection 13a having a semicircular cross section is provided on the upper surface of the peripheral region of the upper opening of the chamber 19, and an annular groove 13b having a trapezoidal cross section is provided on the inner peripheral surface of the upper portion of the valve chamber 19 of the valve body 13. There is. The annular protrusions 13a and 55d are formed to be slightly larger than the annular grooves 55c and 13b, respectively. The annular protrusions 13a on the upper surface of the valve body 13 are engaged with the annular grooves 55c of the horizontal support portion 55a and the vertical support portions 55b are formed. With the annular projection 55d on the outer surface engaged with the annular groove 13b on the inner peripheral surface of the valve chamber 19, the protrusion 31a of the cylinder body 31 is inserted into the valve chamber 19 of the valve body 13 to remove the cylinder body 31. When attached to the upper portion of the valve body 13, the annular protrusions 13a and 55d are deformed and closely fit into the annular grooves 55c and 13b, so that the sealing performance is improved.

  In the present embodiment, as described above, the horizontal support portion 55a of the diaphragm 55 is provided with the annular groove 55c, the vertical support portion 55b is provided with the annular protrusion 55d, and the annular groove 55c and the annular protrusion 55d are respectively provided on the upper portion of the valve body 13. The annular projection 13a and the annular groove 13b on the inner peripheral surface of the valve chamber 19 are engaged with each other. However, an annular protrusion is provided on the horizontal support portion 55a of the diaphragm 55 and an annular groove is provided on the vertical support portion 55b, and the provided annular protrusion and annular groove are respectively provided on the upper portion of the valve body 13 and the valve chamber 19. You may make it engage with the annular protrusion provided in the inner peripheral surface, and provide an annular protrusion or an annular groove in both the horizontal support part 55a and the vertical support part 55b, or one of the horizontal support part 55a and the vertical support part 55b. Only the annular groove or the annular protrusion may be provided only in this case.

  In the valve device according to the present invention, one of the valve body 15 and the valve seat 21 is further provided with a flat annular surface 57, and a convex surface in a direction adjacent to the annular surface 57 and away from the other of the valve body 15 and the valve seat 21. A convex contact curved surface 59 that curves and extends is formed, and a flat contact surface 61 that faces the annular surface 57 and extends parallel to the annular surface 57 is formed on the other side of the valve body 15 and the valve seat 21. ing. In the present embodiment, as shown in FIGS. 3 and 4, a ring-shaped rib 63 extending toward the valve seat 21 is provided on the bottom surface of the valve body 15 facing the valve seat 21. An annular flat annular surface 57 is formed on the top of the rib 63, and a flat contact surface 61 that faces the annular surface 57 and extends parallel to the annular surface 57 is formed on the valve seat 21. . Further, on the side surface of the rib 63, a convex contact curved surface 59 that is curved and extends in a convex shape from the inner peripheral side of the annular surface 57 in the direction away from the valve seat 21 is formed. The convex contact curved surface 59 is formed so that the tangent plane of the convex contact curved surface 59 at the boundary between the annular surface 57 and the convex contact curved surface 59 extends parallel to the annular surface 57. preferable.

  In this way, the annular surface 57 is formed on the top surface of the rib 63 provided on the bottom surface of the valve body 15, and the contact surface 61 that faces the annular surface 57 and extends parallel to the annular surface 57 on the valve seat 21. If the valve body 15 is made to approach the valve seat 21 and seated, the annular surface 57 of the valve body 15 and the contact surface 61 of the valve seat 21 make surface contact. Therefore, the impact when seated can be reduced, and the generation of particles can be suppressed. Further, if the convex contact curved surface 59 is provided adjacent to the annular surface 57, the valve element 15 is further moved from the state where the annular surface 57 of the valve body 15 is seated on the contact surface 61 of the valve seat 21. When pressed against, the rib 63 is deformed, and the convex contact curved surface 59 comes into contact with the contact surface 61 of the valve seat 21. At this time, the convex contact curved surface 59 and the contact surface 61 are in line contact. That is, the contact between the valve element 15 and the valve seat 21 shifts from surface contact to line contact. Due to such a transition from surface contact to line contact, the pressing force per unit area of the valve body 15 against the valve seat 21 is increased, and the sealing property is improved.

  Further, if the annular surface 57 extends parallel to the tangent plane of the convex contact curved surface 59 at the boundary with the convex contact curved surface 59, the boundary does not become edge-shaped, and therefore, it abuts against the contact surface 61. The area on the valve body 15 in contact can smoothly transition from the annular surface 57 to the convex contact curved surface 59, and it is possible to suppress the generation of particles due to the friction between the valve body 15 and the valve seat 21 at the boundary. . Therefore, as the radius of curvature of the convex contact curved surface 59 is larger, the boundary between the annular surface 57 and the convex contact curved surface 59 becomes smoother, and the effect of suppressing the generation of particles is enhanced. The radius of curvature of the convex contact curved surface 59 means the radius of a circle that approximates the curve line formed by the convex contact curved surface 59 in the cross section of the rib 63.

  The annular surface 57 is preferably formed so that its inner diameter is larger than the outer diameter of the connection end of the stem 35c press-fitted into the valve body 15. With such an inner diameter, when the valve body 15 is further pressed against the valve seat 21 by the stem 35c while the annular surface 57 of the rib 63 is in contact with the contact surface 61 of the valve seat 21, the valve body 15 is pressed. The central portion of 15 is deformed in a convex shape toward the valve seat 21 side. By the deformation of the ribs 63 accompanying the deformation of the valve body 15, the convex contact curved surface 59 extending from the inner peripheral side of the annular surface 57 can be surely brought into contact with the contact surface 61. For this reason, it is preferable that the region between the central portion 15b of the bottom surface of the valve body 15 and the connection end of the stem 35c press-fitted into the valve body 15 be thin so that the valve body 15 is easily deformed.

  As shown in FIG. 4, a bottom surface portion (hereinafter, referred to as a bottom surface central portion 15b) of the valve body 15 surrounded by the annular rib 63 is formed flat, and the bottom surface central portion 15b and the convex contact portion are formed. It is preferable that the curved surface 59 is connected to the curved surface 59 by the concave curved surface 15c. Since the central portion 15b of the bottom surface is flat, stress concentration is less likely to occur when the valve body 15 is deformed by being pressed by the stem 35c, and durability is improved. Further, since the bottom center portion 15b and the convex contact curved surface 59 are connected by the concave curved surface 15c, no corner is formed at the boundary between the two, and stress concentration due to deformation of the rib 63 is less likely to occur. And durability is improved.

  Further, in the present embodiment, a convex auxiliary curved surface 65 curved in a convex shape in a direction away from the annular surface 57 is formed on the side surface of the rib 63 opposite to the convex contact curved surface 59 with the annular surface 57 interposed therebetween. Has been done. By making the side surfaces of the ribs 63 curved in this way, it becomes easier to absorb the impact when the valve body 15 is seated on the valve seat 21, and the effect of suppressing the generation of particles is achieved. The radius of curvature of the convex contact curved surface 59 is preferably larger than the radius of curvature of the convex auxiliary curved surface 65. In this case, the contour change from the annular surface 57 to the convex contact curved surface 59 is more gradual than the contour change from the annular surface 57 to the convex auxiliary curved surface 65. The smooth transition from the surface contact with the contact surface 61 of the valve 21 to the line contact between the convex contact curved surface 59 and the contact surface 61 of the valve seat 21 enhances the effect of suppressing the generation of particles. Further, similarly to the convex contact curved surface 59, the tangential plane of the convex auxiliary curved surface 65 at the boundary between the convex auxiliary curved surface 65 and the annular surface 57 is parallel to the annular surface 57. It is preferable that it is formed so as to extend. As a result, no edge is formed at the boundary, and it is possible to suppress the generation of particles due to the edge being scraped by the impact when the valve body 15 is seated on the valve seat 21.

  The material of the valve body 13, the valve body 15, the cylinder body 31, the piston 35, and the diaphragm 55 is, for example, PVC (vinyl chloride resin), PVDF (polyvinylidene fluoride), PP (polypropylene), PTFE (polytetrafluoro). Ethylene), PFA (perfluoroalkoxyethylene), or the like.

  Next, the operation of the diaphragm valve 11 will be described with reference to FIGS. 5 and 6 in addition to FIGS.

  During normal operation when the working fluid is not supplied from the working fluid supply port 45 to the drive unit 17, the piston 35 of the drive unit 17 is urged downward by the compression coil spring 37 and pushed down. As a result, the valve body 15 is pressed against the valve seat 21, and the diaphragm valve 11 is closed as shown in FIG. When the working fluid is supplied to the working fluid supply port 45 of the drive unit 17 from this state, the fluid pressure of the working fluid flowing into the lower space 41 of the cylinder portion acts upward on the piston main body 35a, and the piston 35 causes the compression coil spring 37. It is pushed up against the urging force of. As a result, the valve body 15 separates from the valve seat 21, and the diaphragm valve 11 is opened as shown in FIG.

  When the supply of the working fluid to the working fluid supply port 45 is stopped, the piston 35 is again urged downward by the compression coil spring 37 and pushed down, and as shown in FIG. Sits on the valve seat 21. At this time, first, as shown in FIG. 6A, the annular surface 57 of the rib 63 of the valve body 15 comes into surface contact with the contact surface 61 of the valve seat 21. When the piston 35 moves further downward, the central portion of the valve body 15 is moved downward by the stem 35c of the drive unit 17 in a state where the annular surface 57 of the rib 63 of the valve body 15 is in contact with the contact surface 61 of the valve seat 21. Pressed. Therefore, as shown in FIG. 5B, the central portion of the valve body 15 is deformed in a downward convex shape, and the tips of the ribs 63 are pushed outward. With such deformation of the valve body 15, as shown in FIG. 6B, the convex contact curved surface 59 on the side surface of the rib 63 of the valve body 15 is changed to the contact surface 61 of the valve seat 21. The contact between the valve element 15 and the valve seat 21 shifts from surface contact to line contact.

  Thus, in the diaphragm 11, the annular surface 57 of the valve body 15 and the contact surface 61 of the valve seat 21 come into surface contact immediately after the valve body 15 is seated by approaching the valve seat 21, and the drive unit 17 is driven. It receives the pressing force (thrust) by a large area. Therefore, the impact when the valve body 15 is seated on the valve seat 21 is reduced, and the generation of particles can be suppressed. When the drive unit 17 further presses the valve body 15 against the valve seat 21 from the state where the annular surface 57 of the valve body 15 and the contact surface 61 of the valve seat 21 are in contact with each other, the valve body 15 is deformed. Then, the convex contact curved surface 59 adjacent to the annular surface 57 of the rib 63 comes into contact with the contact surface 61 of the valve seat 21, and the contact between the valve body 15 and the valve seat 21 is changed from the surface contact. Line contact with a smaller contact area. Therefore, even if the pressing force of the valve body 15 against the valve seat 21 by the drive unit 17 is the same, the pressing force per unit area is high and the sealing property is improved. Therefore, the pressing force of the drive unit 17 is weakened to weaken the impact of the valve body 15 on the valve seat 21 when the valve seat 15 is seated to further suppress the generation of particles, and it is also possible to secure good sealing performance. .

  Further, the convex contact curved surface 59 is formed so that the tangent plane of the convex contact curved surface 59 at the boundary between the annular surface 57 and the convex contact curved surface 59 extends parallel to the annular surface 57. For example, since the boundary between the annular surface 57 and the convex contact curved surface 59 does not form an edge shape, the annular surface 57 of the valve body 15 and the contact surface 61 of the valve seat 21 are not in contact with each other, and thus the convex shape of the valve body 15 is changed. The line contact between the contact curved surface 59 and the contact surface 61 of the valve seat 21 can be smoothly changed, and the valve body 15 or the valve seat 21 is scraped by friction between the valve body 15 and the valve seat 21 at the boundary. Generation of particles can be suppressed.

Next, another embodiment of the valve device according to the present invention will be described.
FIG. 7 shows essential parts of a diaphragm valve 71 according to a second embodiment of the valve device of the present invention. In FIG. 7, constituent elements common to the first embodiment are designated by the same reference numerals as those in the first embodiment. The structure of the diaphragm valve 71 of the second embodiment is the same as the diaphragm valve 11 of the first embodiment, except for the structures of the valve body 73 and the valve seat 75, so here, the valve body 73 and the valve seat are used. The structure of 75 will be mainly described.

  In the first embodiment, the valve body 15 has a cone shape, but the shape of the valve body of the valve device is not limited to the cone shape. The valve body 73 of the diaphragm valve 71 of the second embodiment has a disc shape, and extends radially outward from the outer peripheral portion of the upper end portion thereof, like the diaphragm valve 11 of the first embodiment. It is supported by the valve body 13 so as to face the valve seat 75 via the diaphragm 77. The valve seat 75 is formed on an upward surface of an annular step portion formed around the opening of the inflow passage 25 to the valve chamber 19.

  Similar to the valve body 15 and the valve seat 21 of the diaphragm valve 11 of the first embodiment, an annular shape extending toward the valve seat 75 is formed on the outer peripheral portion of the bottom surface of the valve body 73 facing the valve seat 75. Ribs 79 are provided. An annular flat annular surface 81 is formed on the top of the rib 79, and a flat abutting surface 83 that faces the annular surface 81 and extends parallel to the annular surface 81 is formed on the valve seat 75. ing. The side surface of the rib 79 is provided with a convex contact curved surface 85 and a convex auxiliary curved surface 87 that extend in a convex shape from the inner peripheral side and the outer peripheral side of the annular surface 81 in the direction away from the valve seat 75. The convex contact curved surface 85 and the convex auxiliary curved surface 87 are formed such that the tangent plane at the boundary with the annular surface 81 extends parallel to the annular surface 81.

  In the valve body 73 of the present embodiment, the male screw provided on the outer periphery of the connection end 35d of the stem 35c of the drive unit 17 is screwed into the female screw formed in the connection hole 73a at the upper center of the valve body 73 to allow the stem 35c. Is connected to the connection end 35d of the drive seat 17 and is driven by the drive unit 17 in a direction of approaching and separating from the valve seat 75. However, the connection of the valve body 73 to the connection end 35d of the stem 35c is not limited to screwing, and an appropriate method can be adopted. For example, as in the first embodiment, the valve body 73 may be connected to the connection end 35d of the stem 35c by press-fitting the connection end 35d of the stem 35c into the valve body 73. The outer diameter of the connection end 35d of the stem 35c is smaller than the inner diameter of the annular rib 79.

  In the diaphragm valve 71 of the present embodiment, when the valve body 73 is pushed down by the drive of the stem 35c of the drive unit 17 from the open state in which the valve body 73 is separated from the valve seat 75, it is shown in FIG. As described above, the annular surface 81 of the rib 79 of the valve body 73 comes into surface-contact with the contact surface 83 of the valve seat 75 to be seated, and the impact at the time of sitting is reduced. Further, when the valve body 73 is pushed downward by the drive of the stem 35c of the drive unit 17 from the state where the annular surface 81 of the valve body 73 is in contact with the contact surface 83 of the valve seat 75, the central portion of the valve body 15 is pressed. Bends in a convex shape toward the valve seat 75. Due to the deformation of the rib 79 associated with the deformation of the valve body 15, as shown in FIG. 7B, the convex contact curved surface 85 extending from the inner peripheral side of the annular surface 81 forms the valve seat 75. It comes into line contact with the contact surface 83, and the pressing force per unit area is increased. In this embodiment, at this time, the convex auxiliary curved surface 87 extending from the outer peripheral side of the annular surface 81 also comes into line contact with the outer peripheral surface 89 of the annular groove to perform an additional sealing function. Other actions and effects of the diaphragm valve 71 of the second embodiment are the same as those of the diaphragm valve 11 of the first embodiment, and therefore the description thereof is omitted here.

  FIG. 8 shows a main part of a diaphragm valve 91 according to a third embodiment of the valve device of the present invention. In FIG. 8, the same components as those in the first embodiment are designated by the same reference numerals as those in the first embodiment. The structure of the diaphragm valve 91 of the third embodiment is the same as that of the diaphragm valve 11 of the first embodiment, except for the structures of the valve body 93 and the valve seat 95, so here, the valve body 93 and the valve seat are used. The description will focus on 95.

  In the first embodiment, the rib 63 having the annular surface 57 formed on the top is provided on the valve body 15 side, and the contact surface 61 with which the annular surface 57 abuts is provided on the valve seat side. The arrangement of the contact surface 61 is not limited to the arrangement of the first embodiment. The valve element 93 of the diaphragm valve 91 of the third embodiment is similar to that of the first embodiment, and has a generally cylindrical shape with a tapered tip end portion, and is radially outward from the outer peripheral portion of its upper end portion. It is supported by the valve body 13 so as to face the valve seat 95 via a diaphragm 97 that extends toward one side. The valve seat 95 is formed around the opening of the inflow passage 25 to the valve chamber 19, and the valve seat 95 is provided with an annular rib 99 that projects and extends toward the valve body 93. In the third embodiment, the separate rib 99 is attached to the valve seat 95, but the rib 99 may be formed integrally with the valve seat 95.

  An annular flat annular surface 101 is formed on the top of the rib 99, and a flat abutment surface 103 facing the annular surface 101 and extending parallel to the annular surface 101 is formed on the bottom of the valve body 93. Has been formed. In addition, on the side surface of the rib 99, a convex contact curved surface 105 and a convex auxiliary curved surface 107 that are curved and extend in a convex shape from the inner peripheral side and the outer peripheral side of the annular surface 101 in the direction away from the valve body 93, respectively. The convex contact curved surface 105 and the convex auxiliary curved surface 107 are formed such that the tangent plane at the boundary with the annular surface 101 extends parallel to the annular surface 101. Further, a wedge-shaped annular notch 109 is provided on the outer peripheral side of the base end of the rib 99.

  The valve body 93 of the present embodiment is configured such that a female thread portion provided at the connection end 35d of the stem 35c of the drive unit 17 is screwed with a male thread portion formed so as to project to the center of the upper portion of the valve body, thereby connecting the stem 35c. It is connected to the valve 35d and is driven in a direction of approaching and separating from the valve seat 95. However, the connection of the valve body 93 to the connection end 35d of the stem 35c is not limited to screwing, and an appropriate method can be adopted. For example, similarly to the first embodiment, the valve body 93 may be connected to the connection end 35d of the stem 35c by press-fitting the connection end 35d of the stem 35c into the valve body 93.

  In the diaphragm valve 97 of the present embodiment, when the valve body 93 is pushed down by the drive of the stem 35c of the drive unit 17 from the open state in which the valve body 93 is separated from the valve seat 95, it is shown in FIG. Thus, the abutment surface 103 on the bottom surface of the valve body 93 comes into surface-contact with the annular surface 101 of the rib 99 provided on the valve seat 95 to be seated, and the impact at the time of sitting is reduced. Furthermore, when the valve body 93 is pushed downward by the drive of the stem 35c of the drive unit 17 from the state where the contact surface 103 of the valve body 93 contacts the annular surface 101 of the rib 99 of the valve seat 95, the rib 99 is moved downward. It is pressed downward by the valve element 93, and the tip of the rib 99 bends outward due to the presence of the notch 109 on the outer peripheral side of the rib 99. As a result, as shown in FIG. 8B, the convex contact curved surface 105 extending from the inner peripheral side of the annular surface 101 comes into line contact with the contact surface 103 of the bottom surface of the valve body 93. , The pressing force per unit area is increased. Other actions and effects of the diaphragm valve 91 of the third embodiment are similar to those of the diaphragm valve 11 of the first embodiment, and therefore the description thereof is omitted here.

  FIG. 9 shows a main part of a globe valve 111 according to a fourth embodiment of the valve device of the present invention. The basic structure of the globe valve 111 of the fourth embodiment is the same as that of the diaphragm valve of the first embodiment, except for the structures of the valve body 113 and the valve seat 115. The explanation will focus on the seat.

  In the first to third embodiments, the present invention is applied to the diaphragm valve, but the present invention is a valve that opens and closes when the valve body moves toward and away from the valve seat in a substantially vertical direction. However, the application is not limited to the diaphragm valve. The fourth embodiment is an example in which the present invention is applied to the globe valve 111. Further, in the first to third embodiments, the annular surface and the convex contact curved surface adjacent to the annular surface are formed on the rib provided on the valve body or the valve seat. The curved contact curved surface may be formed at a place other than the top of the rib. In the fourth embodiment, an annular flat annular surface 117 is formed as the valve seat surface of the valve seat 115 and is adjacent to the annular surface 117 by chamfering the peripheral edge of the opening of the inflow passage 25 to the valve chamber 19. The curved surface thus formed is referred to as a convex contact curved surface 119. Further, on the bottom surface of the valve body 113, a flat contact surface 121 that faces the annular surface 117 formed on the valve seat 115 and extends parallel to the annular surface 117 is formed. The convex contact curved surface 119 is formed so that the tangential plane at the boundary with the annular surface 117 extends parallel to the annular surface 117.

  The valve body 113 of the present embodiment has a flat plate shape, and a female screw portion provided at the connecting end 35d of the stem 35c of the drive unit 17 is screwed with a male screw portion formed so as to project to the center of the upper portion of the valve body 113. By connecting them, they are connected to the connecting end 35d of the stem 35c and are driven in a direction of approaching and separating from the valve seat 115. However, the connection of the valve body 113 to the connection end 35d of the stem 35c is not limited to screwing, and an appropriate method can be adopted. For example, as in the first embodiment, the valve body 113 may be connected to the connecting end 35d of the stem 35c by press-fitting the connecting end 35d of the stem 35c into the valve body 113.

  In the globe valve 111 of the present embodiment, when the valve body 113 is pushed down by the drive of the stem 35c of the drive unit 17 from the open state in which the valve body 113 is separated from the valve seat 115, it is shown in FIG. 9 (a). As described above, the contact surface 121 of the bottom surface of the valve body 113 comes into surface-contact with the annular surface 117 of the valve seat 115 to be seated, and the impact during seating is reduced. Furthermore, when the valve body 113 is pushed downward by the drive of the stem 35c of the drive unit 17 from the state where the contact surface 121 of the valve body 113 is in contact with the annular surface 117 of the valve seat 115, the central portion of the valve body 113 is depressed. Bends in a convex shape toward the valve seat 115 side. As a result, as shown in FIG. 9B, the contact surface 121 of the valve body 113 comes into line contact with the convex contact curved surface 119 extending from the inner peripheral side of the annular surface 117 of the valve seat 115. Therefore, the pressing force per unit area is increased. The other actions and effects of the fourth embodiment are similar to those of the first embodiment, and therefore the description thereof is omitted here.

  FIG. 10 shows a globe valve 131 according to a fifth embodiment of the valve device of the present invention. The basic structure of the globe valve 131 of the fifth embodiment is the same as that of the first embodiment, except for the structures of the valve body 133 and the valve seat 135, so here, the valve body 133 and the valve seat 135. I will explain mainly.

  In the first to fourth embodiments, the valve body is connected to the connecting end 35d of the stem 35c of the drive unit 17 at the center of the upper portion of the valve body. However, the stem 35c causes the valve body to approach and separate from the valve seat. The connecting portion with the stem 35c is not limited to the center of the upper portion of the valve body as long as it is possible. In the fifth embodiment, the connection end 35d of the stem 35c is formed in a tubular shape, and the valve body 133 is connected to the stem 35c by mounting the outer extending portion of the upper portion of the valve body 133 on the outer peripheral portion of the connection end 35d. It is connected to the end 35d.

  In the present embodiment, an annular rib 137 that projects and extends toward the valve seat 135 is provided inside the outer periphery of the bottom surface of the valve body 133 that is connected to the connection end 35d of the stem 35c. An annular flat annular surface 139 is formed on the top. Further, the valve seat 135 is provided with an annular rib 141 that faces the annular surface 139 and extends so as to project toward the valve body 133, and an annular shape that extends parallel to the annular surface 139 is provided at the top of the rib 141. A flat contact surface 143 is formed. Further, a convex contact curved surface 145 is formed on the side surface of the rib 137 so as to curve in a convex shape from the outer peripheral side of the annular surface 139 in the direction away from the valve seat 135. The convex contact curved surface 145 is formed such that the tangent plane at the boundary with the annular surface 139 extends parallel to the annular surface 139.

  In the globe valve 131 of the present embodiment, when the valve body 133 is pushed down by the drive of the stem 35c of the drive unit 17 from the open state in which the valve body 133 is separated from the valve seat 135, it is shown in FIG. As described above, the annular surface 139 of the rib 137 of the valve body 133 comes into surface-contact with the contact surface 143 formed on the rib 141 of the valve seat 135 to be seated, and the impact at the time of seating is reduced. Further, when the valve body 133 is pushed down by the drive of the stem 35c of the drive unit 17 from the state where the annular surface 139 of the valve body 133 is in contact with the contact surface 143 of the valve seat 135, the pressing force by the stem 35c is reduced. It acts on the outer peripheral portion of the valve body 133, and the central portion of the valve body 133 is concavely curved in a direction away from the valve seat 135. As a result, as shown in FIG. 10B, the convex contact curved surface 145 extending from the outer peripheral side of the annular surface 139 comes into line contact with the contact surface 143 of the valve seat 135, and the unit area The pressing force per hit is increased. Other operations and effects of the globe valve 131 of the fifth embodiment are the same as those of the diaphragm valve 11 of the first embodiment, so description thereof will be omitted here.

  As described above, also in the second to fifth embodiments, similarly to the diaphragm valve 11 of the first embodiment, at the beginning of the seating of the valve body on the valve seat, the valve body makes surface contact with the valve seat. It is possible to reduce the impact at the time of sitting and suppress the generation of particles. In addition, when the valve body is pressed against the valve seat from the seated state, the valve body and the valve seat move from surface contact to line contact, increasing the pressing force per unit area and improving the sealing performance. Can be made.

  Although the present invention has been described above with reference to the illustrated embodiments, the present invention is not limited to the illustrated embodiments and various modifications are possible. For example, in the illustrated first embodiment, the inflow passage 25 is formed as the first flow passage and the outflow passage 29 is formed as the second flow passage, and the inflow passage 25 from the inflow passage 25 to the valve chamber 21 is formed. An annular valve seat 21 is formed around the opening. However, an outflow passage opening to the center of the bottom portion of the valve chamber 19 is formed as the first flow passage, and an inflow passage opening to the side surface of the valve chamber 19 is provided as the second flow passage, and the outflow passage is connected to the valve chamber. An annular valve seat 21 may be formed around the opening to 19. Further, the position of the valve seat 21 is not limited to the bottom of the valve chamber 15 as long as the valve body 15 can be brought into contact with and separated from the valve seat 21.

11 Diaphragm valve 13 Valve body 15 Valve body 17 Drive part 19 Valve chamber 21 Valve seat 25 Inflow passage 29 Outflow passage 55 Diaphragm 57 Annular surface 59 Convex abutment curved surface 61 Abutment surface 63 Rib 65 Convex auxiliary curved surface 71 Diaphragm Valve 73 Valve body 75 Valve seat 77 Diaphragm 79 Rib 81 Annular surface 83 Abutting surface 85 Convex abutting curved surface 87 Convex auxiliary curved surface 91 Diaphragm valve 93 Valve body 95 Valve seat 97 Diaphragm 99 Rib 101 Annular surface 103 Abutting Surface 105 Convex contact curved surface 107 Convex auxiliary curved surface 111 Globe valve 113 Valve body 115 Valve seat 117 Annular surface 119 Convex abutted curved surface 121 Contact surface 131 Globe valve 133 Valve body 135 Valve seat 137 Rib 139 Annular Surface 143 Contact surface 145 Convex contact curved surface

Claims (13)

A valve body having a valve chamber and a first flow passage and a second flow passage communicating with the valve chamber, and an annular valve formed around an opening from the first flow passage to the valve chamber. A valve device comprising a seat and a valve element that is moved in a direction perpendicular to the valve seat by a drive unit and is brought into contact with and separated from the valve seat,
A flat annular surface is provided on one of the valve seat and the valve body, and a convex curved surface extends from one of the inner peripheral side and the outer peripheral side of the annular surface in a direction away from the other of the valve seat and the valve body. A convex contact curved surface is formed, and a flat contact surface is formed on the other of the valve seat and the valve body so as to face the annular surface, and the valve body contacts the valve seat. In addition, after the surface contact between the annular surface and the contact surface, the linear contact between the convex contact curved surface and the contact surface is caused by the deformation of at least one of the valve seat and the valve body. A valve device characterized in that.   The valve device according to claim 1, wherein the convex contact curved surface is formed such that a tangent plane at a boundary between the annular surface and the convex contact curved surface extends parallel to the annular surface.   The valve according to claim 1 or 2, wherein one of the valve seat and the valve body is provided with an annular rib projecting toward the other, and the annular surface is formed on a top portion of the rib. apparatus.   A convex auxiliary curved surface is formed on the side surface of the rib opposite to the convex contact curved surface with the annular surface sandwiched between the annular surface and the convex auxiliary curved surface extending in a convex shape from the annular surface. The valve device according to claim 3, wherein   The valve device according to claim 4, wherein the convex auxiliary curved surface is formed such that a tangent plane at a boundary between the annular surface and the convex auxiliary curved surface extends parallel to the annular surface.   The valve device according to claim 4 or 5, wherein a radius of curvature of the convex contact curved surface is larger than a radius of curvature of the convex auxiliary curved surface.   The valve device according to any one of claims 3 to 6, wherein the rib is formed on a bottom surface of the valve body facing the valve seat.   The valve device according to claim 7, wherein the bottom surface of the valve body is a flat surface, and the side surface of the rib and the flat surface are connected by a concave curved surface.   The valve device according to claim 7, wherein the valve body is connected to a connection end provided at a tip of a stem driven by the drive unit.   The annular surface has an annular shape, the convex contact curved surface is formed on the inner peripheral side surface of the rib, and the outer diameter of the connecting end of the stem is the inner diameter of the annular surface. The valve device according to claim 9, wherein the annular surface is formed so as to be smaller than the above.   The valve device according to claim 9, wherein the valve body is connected to the connection end by press-fitting the connection end of the stem into the valve body.   The diaphragm according to any one of claims 1 to 11, further comprising a diaphragm extending radially outward from the periphery of the front valve body, the valve body being supported by the valve body via the diaphragm. Valve device.   The valve device according to any one of claims 1 to 12, wherein the drive unit is an air drive type or a spring drive type.

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