JP2017180541A - Seal structure, valve and manufacturing method of seal structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal structure capable of suppressing fluctuation of a pressure receiving area.SOLUTION: A seal structure includes: a seal member 12 having a seal surface 12a, and capable of moving between a position where the seal surface 12a is seated to a valve seat 16 and a position where the seal surface 12a separates from the valve seat 16; and expansion suppression means 40 that when the seal surface 12a of the seal member 12 is seated to the valve seat 16, suppresses the seal surface 12a from expanding at a position along the valve seat 16. The expansion suppression means 40 is configured to more enhance stress of a portion on the seal surface 12a side than a portion on the opposite side to the seal surface 12a in the seal member 12.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a seal structure, a valve, and a method for manufacturing the seal structure.

  Conventionally, a seal structure used in, for example, a valve member or the like is disclosed in Patent Document 1 below. As shown in FIG. 25, the seal structure disclosed in Patent Document 1 includes a seal member 83 disposed in a circular cavity 82 provided on the lower end surface of the valve body 81. The seal member 83 is made of an elastomer, and is seated on the sealed surface 85 when the valve body 81 is pressed by the spring force of the coil spring 84. The sealed surface 85 is formed in an annular shape, and the inner peripheral surface of the sealed surface 85 defines a flow path through which a fluid that presses the sealing surface 83a flows. For this reason, the inner surface of the sealed surface 85 in the seal surface 83a is a pressure receiving surface that receives pressure from the fluid.

JP 2003-21455 A

  The sealed surface 85 has a shape protruding toward the seal member 83. When the seal surface 83 a of the seal member 83 is pressed against the surface to be sealed 85, the seal surface 83 a is deformed along the shape of the surface to be sealed 85. For this reason, in the seal structure of Patent Document 1, the pressure receiving area varies due to the deformation of the seal surface 83a. Since fluctuation of the pressure receiving area affects the valve opening pressure, it is preferable that the pressure receiving area does not change.

  Therefore, the present invention has been made in view of the above prior art, and an object of the present invention is to provide a seal structure that can suppress fluctuations in the pressure receiving area.

  In order to achieve the above object, the present invention provides a seal member having a seal surface, the seal surface being movable between a position where the seal surface is seated on a seal seat and a position where the seal surface is separated from the seal seat. And a bulge suppressing means that suppresses expansion of the position of the seal surface along the seal seat when the seal surface of the seal member is seated on the seal seat.

  In the present invention, since the swelling surface of the sealing member is restrained from swelling at a position along the seal seat by the swelling restraining means, the pressure receiving surface partitioned by the seal seat when the seal surface is seated on the seal seat. It can suppress that the area of fluctuates. Therefore, according to the present invention, it is possible to suppress the deformation of the pressure receiving area by suppressing excessive deformation of the sealing surface while ensuring the sealing performance between the sealing surface and the sealing seat.

  The said swelling suppression means may be comprised so that it may also suppress that surfaces other than the said seal surface in the said seal member swell when the said seal surface of the said seal member seats on the said seal seat.

  When the surface other than the sealing surface swells, the deformation amount of the entire sealing member in the moving direction of the sealing member is easily changed. For this reason, for example, when the coil spring is used to generate a force for pressing the seal member against the seal seat, the extension amount of the coil spring is affected. On the other hand, it is possible to prevent the amount of elongation of the coil spring from changing from the design value (correctly difficult to change) by suppressing the surface other than the sealing surface from expanding. Therefore, the set load of the coil spring can be maintained at a predetermined value, and the force necessary for separating the seal surface from the seal seat can be stabilized.

  The said swelling suppression means may be comprised so that the stress of the site | part on the seal surface side may be raised rather than the site | part on the opposite side to the said seal surface in the said sealing member.

  In this aspect, by increasing the stress at the site on the seal surface side, it is possible to suppress the swelling toward the seal seat in the entire seal surface. That is, when the stress on the part on the opposite side (back side) of the seal member as well as on the seal surface side is also increased, the stress on the part on the seal surface side is increased, Since the stress is less likely to act toward the seal surface, the stress acts toward the seal surface, and as a result, the seal surface tends to swell. On the other hand, if the stress at the site on the back side of the seal member is not increased, the stress at the site on the seal surface side is increased and the stress tends to act toward the back side, so the seal surface swells It is hard to be in a state. Therefore, fluctuations in the pressure receiving area can be further suppressed. Moreover, the excessive deformation | transformation in the whole sealing member can be suppressed.

  The said swelling suppression means may be comprised so that the said stress may be raised by compressing the site | part by the side of the sealing surface of the said sealing member from the outer side.

  In this aspect, excessive deformation of the seal surface can be suppressed while the configuration for applying stress to the seal member is not complicated. Therefore, fluctuations in the pressure receiving area can be suppressed with a simple configuration.

  The bulge suppressing means is a recess formed in the holding body that holds the seal member, and is attached to the recess at least at a site on the seal surface side in a direction orthogonal to the moving direction of the holding body. In this state, the seal member may be constituted by the concave portion having an inner dimension smaller than an outer dimension of a part on the seal surface side.

  In this aspect, the effect of the bulging suppression means can be stably exhibited with a simple configuration that only determines the dimensions of the component parts. Therefore, suppression of excessive deformation of the seal surface can be stabilized. And since the compressive stress of the direction orthogonal to the moving direction of a holding body can be generated in a sealing member, the dent of a sealing surface when pressed by a seal seat can be suppressed.

  The bulge suppressing means generates the stress at a site closer to the seal surface than an end surface on the opposite side of the seal surface of the seal member and on a side closer to the end surface than the seal surface. It may be configured as follows.

  In this aspect, stress is generated at the site where the sealing surface of the sealing member is removed, so that excessive deformation of the sealing member can be suppressed while ensuring adequate flexibility of the sealing surface so as to ensure sealing performance. it can. And since the stress of the site | part by the side of a sealing surface can be raised, the fluctuation | variation of a pressure receiving area can be suppressed. Further, since no stress is generated on the seal surface itself or excessive stress is not generated, the seal surface can be prevented from undulating and the pressure receiving area can be set more accurately.

  The seal surface may protrude toward the seal seat from the opening end of the recess.

  In this aspect, since the seal surface protrudes to the seal seat side from the opening end of the recess, the recess can generate stress at a site where the seal surface of the seal member is removed, and can secure sealing performance. Appropriate flexibility of the sealing surface can be secured. Further, it is possible to generate stress at a site closer to the seal surface than the end surface opposite to the seal surface in the seal member and on the end surface side opposite to the seal surface. Therefore, stress can be generated at a desired site with a simple configuration. In addition, even if the seal member is worn at the contact portion with the seal seat, it is possible to avoid the opening end of the recess from contacting the casing outside the seal seat.

  The said swelling suppression means may be comprised so that it may function also as an engaging part which prevents that the said sealing member remove | deviates from the said recessed part. In this aspect, since the bulging suppressing means also serves as a means for preventing the sealing member from coming off from the recess, the structure for preventing the sealing member from being detached from the holding body can be simplified. Therefore, a sealing function can be ensured with a simple configuration.

  The concave portion may include an engaging portion that prevents the seal member from being detached from the concave portion. In this aspect, since the seal member can be prevented from coming off the holding body, a sealing function can be ensured.

  The open end of the recess may be rounded. In this aspect, it is possible to prevent the seal member from being damaged at the opening end of the concave portion, although the compressive stress is generated in the seal member in a direction orthogonal to the moving direction of the holding body. Further, when the sealing member is put in the recess and attached, the sealing member can be easily put in the recess.

  The seal member has a circular cross-sectional shape parallel to the seal surface, and the bulge suppressing means is configured to increase the stress at a portion on the seal surface side from the entire circular periphery of the seal member. It may be. In this aspect, since the bulging suppression means increases the stress at a predetermined portion from the entire circumference of the seal member having a circular cross section, the direction of the stress generated in the seal member is uniform, so that excessive stress concentration does not occur in the seal member. Can be. Therefore, the lifetime of the seal member can be increased.

  The concave portion may have a truncated cone shape with a small diameter on the opening end side. In this aspect, by inserting a seal member having an outer diameter (outer dimension) larger than the inner diameter (inner dimension) of the opening end of the recess into the recess, the stress on the seal surface side portion of the seal member is increased. Can be configured. In addition, the opening end of the recess can also function as an engaging portion that prevents the seal member from coming off the recess. According to this, a recessed part can be comprised from a simple shape, and manufacture of a recessed part becomes easy.

  The seal member may have a truncated cone shape with a small diameter on the seal surface side. In this aspect, by inserting the large-diameter side of the seal member (the end surface opposite to the seal surface) into the back side of the recess, the large-diameter side portion of the seal member is related to the opening-side portion in the recess. In combination, the seal member can be configured to be prevented from coming off from the recess. According to this, the sealing member which prevented coming off from a recessed part can be comprised from a simple shape, and manufacture of a sealing member becomes easy.

  The present invention includes the seal structure, a seal seat on which the seal surface of the seal member is seated, and a biasing member that biases the seal member in a direction in which the seal surface is seated on the seal seat, Of the seal surfaces, a valve pressed by a fluid flowing in a space defined by the seal seat serves as a pressure receiving surface for moving the seal member.

  This invention is a manufacturing method of the said seal structure, Comprising: The said recessed part is opening to the said seal seat side, and is a manufacturing method of the seal structure which attaches the said sealing member to the said recessed part from the said seal seat side.

  In the manufacturing method of the seal structure of the present invention, it is possible to easily obtain a configuration that suppresses excessive deformation of the seal member and suppresses variation in the pressure receiving area by a simple method of simply attaching the seal member to the recess from the seal seat side. it can.

  As described above, according to the present invention, fluctuations in the pressure receiving area can be suppressed in the seal structure.

It is a figure showing roughly the valve to which the seal structure concerning a 1st embodiment of the present invention was applied. It is a figure for demonstrating the said seal structure. It is a figure for demonstrating the dimension of the sealing member and recessed part in the said seal structure. (A) It is a figure for demonstrating the swelling of the seal surface in a comparative example, (b) It is a figure for demonstrating the bulge of the seal surface in the said seal structure. It is a figure for demonstrating the modification of the seal structure which concerns on 1st Embodiment of this invention. It is a figure for demonstrating the modification of the seal structure which concerns on 1st Embodiment of this invention. It is a figure for demonstrating the modification of the seal structure which concerns on 1st Embodiment of this invention. It is a figure for demonstrating the modification of the seal structure which concerns on 1st Embodiment of this invention. It is a figure for demonstrating the seal structure which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the seal structure which concerns on 3rd Embodiment of this invention. It is a figure for demonstrating the seal structure which concerns on the modification of 3rd Embodiment of this invention. It is a figure for demonstrating the seal structure which concerns on the modification of 3rd Embodiment of this invention. It is a figure for demonstrating the seal structure which concerns on 4th Embodiment of this invention. It is a figure for demonstrating the seal structure which concerns on the modification of 4th Embodiment of this invention. (A) (b) It is a figure for demonstrating the seal structure which concerns on 5th Embodiment of this invention. It is a figure which shows the notch part of a holding body. It is a figure for demonstrating the seal structure which concerns on 6th Embodiment of this invention. It is a figure for demonstrating the seal structure which concerns on the modification of 6th Embodiment of this invention. It is a figure for demonstrating the seal structure which concerns on the modification of 6th Embodiment of this invention. It is a figure for demonstrating the seal structure which concerns on the modification of 6th Embodiment of this invention. It is a figure for demonstrating the seal structure which concerns on 7th Embodiment of this invention. (A) (b) It is a figure for demonstrating the seal structure which concerns on 8th Embodiment of this invention. It is a figure for demonstrating the seal structure which concerns on the modification of 8th Embodiment of this invention. (A) (b) It is a figure for demonstrating the seal structure which concerns on the modification of 8th Embodiment of this invention. It is a figure which shows roughly the valve to which the conventional seal structure was applied.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

(First embodiment)
The seal structure according to the first embodiment is applied to a valve 10 that can be used as a safety valve, for example. In addition, the seal structure of 1st Embodiment is not restricted to what is used for the valve 10, It is also possible to apply to other valve apparatuses, such as a non-return valve and a pressure-reduction valve.

  The valve 10 includes a seal member 12, a valve member 14 that holds the seal member 12, a casing 18 in which a valve seat 16 that is a seal seat is formed, a coil spring 20 that is a biasing member, and a coil spring 20. A pressing member 22 for pressing and an adjusting member 24 for adjusting the elastic force of the coil spring 20 are provided.

  The housing 18 includes a body portion 28 formed in a cylindrical shape that is long in one direction, and a bottom portion 29 that is positioned at an end portion of the body portion 28 in the longitudinal direction. An end portion (upper end portion in FIG. 1) opposite to the bottom portion 29 of the body portion 28 is open. A bottomed cylindrical adjustment member 24 is disposed at the open end of the body portion 28, and the open end portion of the body portion 28 is closed by the adjustment member 24.

  The bottom portion 29 is connected to one end portion of the body portion 28 so as to close the opening of one end portion (the lower end portion in FIG. 1) of the body portion 28 in the longitudinal direction. The bottom portion 29 has an inner surface 29 a that extends in a direction orthogonal to the longitudinal direction of the body portion 28.

  The bottom portion 29 is connected to an extending portion 30 extending in the longitudinal direction of the body portion 28 from the center portion of the outer surface. A through hole that defines an inflow path 32 through which fluid flows is formed from the bottom 29 to the extension 30. The through hole is formed from the distal end surface of the extending portion 30 to the inner surface 29 a of the bottom portion 29.

  Inside the trunk portion 28, the valve member 14, the coil spring 20, and the pressing member 22 are accommodated. The valve member 14 includes a holding body 34 having an outer peripheral surface that contacts the inner peripheral surface of the body portion 28, and a valve rod 35 connected to one end surface of the holding body 34 (one end surface in the longitudinal direction of the body portion 28). Have The valve member 14 is constituted by a single member in which a holding body 34 and a valve rod 35 are integrally formed.

  A concave portion 37 is formed in the tip surface 34 a (end surface opposite to the valve rod 35) of the holding body 34, that is, the end surface 34 a facing the bottom portion 29, and the seal member 12 is held in the concave portion 37. That is, the holding body 34 and the seal member 12 constitute a valve body for opening and closing the valve 10. The seal member 12 is made of an elastomer such as rubber or resin.

  The pressing member 22 includes a pressing portion 22a in which a through-hole through which the valve rod 35 is inserted and a side surface portion 22b extending in the axial direction along the trunk portion 28 from the outer periphery of the pressing portion 22a. The coil spring 20 is sandwiched between the pressing portion 22a and the holding body 34. A male screw 22c is formed on the outer peripheral surface of the side surface portion 22b.

  Female threaded portions 28 a and 24 a are provided on the inner peripheral surface of the body portion 28 on the open end side and the inner peripheral surface of the adjustment member 24. A male screw 22c provided on the side surface portion 22b of the pressing member 22 is screwed into the female screw portion 28a and 24a. Therefore, the pressing member 22 can be moved in the longitudinal direction of the trunk portion 28 by rotating the adjustment member 24 about the axis of the trunk portion 28. Thereby, the compression amount of the coil spring 20 can be adjusted.

  The coil spring 20 is formed by forming a wire having a rectangular cross section into a coil shape. By using the coil spring 20 made of a wire having a rectangular cross section, it is possible to prevent the coil spring 20 from buckling in a compressed state without reducing the elastic coefficient of the coil spring 20.

  The body portion 28 is provided with an exhaust hole 28b and a back pressure exhaust hole 28c. A back pressure passage 34 b is formed on the outer peripheral surface of the holding body 34. The exhaust hole 28b is a hole for discharging the fluid that has flowed into the body part 28 through the inflow path 32 to the outside of the body part 28 when the valve is opened. The back pressure exhaust hole 28 c is a hole for discharging the fluid used for applying the back pressure to the holding body 34 to the outside of the body portion 28. The back pressure passage 34 b is a passage for guiding the fluid introduced into the body portion 28 through the inflow passage 32 to the back pressure side of the holding body 34.

  The seal member 12 has a truncated cone shape, and as shown in FIG. 2, the longitudinal section of the seal member 12 is formed in a trapezoidal shape. In other words, the seal member 12 is formed in a truncated cone shape in which the seal surface 12a is smaller in diameter than the opposite end surface 12b. On the other hand, the concave portion 37 of the holding body 34 is also a truncated cone-shaped concave portion, and the cross-sectional shape of the concave portion 37 is trapezoidal. That is, the concave portion 37 is formed in a truncated cone shape in which the inner diameter of the bottom surface 37a is smaller than the inner diameter of the edge (outer edge) 37c on the opening side. The seal member 12 is attached to the recess 37 such that a portion on the seal surface 12 a side facing the valve seat 16 protrudes outside the recess 37. The back end surface (upper end surface in FIG. 1) 12b of the seal member 12 faces the bottom surface 37a of the recess 37 and is in contact with the bottom surface 37a. Moreover, the site | part in the recessed part 37 among the side surfaces 12c of the sealing member 12 is facing the internal peripheral surface 37b of the recessed part 37, and is contacting this internal peripheral surface 37b.

  A valve seat 16, which is a seal seat on which the seal member 12 is seated, is formed on the inner surface 29 a of the bottom portion 29 of the housing 18. The valve seat 16 is provided along the outer periphery of the outlet of the inflow passage 32 and has an annular shape. The holding body 34 is movable in the vertical direction in FIG. And the surface pressed by the fluid which flows through the space defined by the valve seat 16 among the sealing surfaces 12a becomes a pressure receiving surface for moving the holding body 34. The seal member 12 is movable between a position where the seal surface 12 a facing the valve seat 16 is seated on the valve seat 16 and a position where the seal surface 12 a is separated from the valve seat 16. Even when the seal surface 12 a is seated on the valve seat 16, the inner surface 29 a of the bottom 29 and the tip end surface (lower end surface in FIG. 2) 34 a of the holding body 34 do not come into contact with each other. Therefore, the sealing performance by the sealing member 12 can be ensured.

  The valve seat 16 has a shape protruding from the inner surface 29a of the bottom portion 29 toward the holding body 34 side. The tip of the valve seat 16 may be flat or curved. Even if the tip is flat, the periphery of the tip is curved.

  The seal member 12 is held by the recess 37 in a state where a portion of the seal surface 12 a side protrudes from the recess 37. And the site | part hold | maintained by the outer edge 37c of the recessed part 37 among the sealing members 12 is the state compressed to radial direction (direction orthogonal to the moving direction of the holding body 34). Specifically, as shown in FIG. 3, the length H2 in the thickness direction of the seal member 12 is longer than the length H1 in the depth direction of the recess 37. It protrudes from the outer edge 37 c (opening edge) of the recess 37 toward the valve seat 16. The ratio of the protrusion amount H3 (= H2-H1) of the seal member 12 to the length H2 in the thickness direction of the seal member 12 is preferably about 1/10 to 1/3. Within this range, even if the seal member 12 is compressed in the recess 37, excessive compressive stress does not occur on the seal surface 12a, so the flexibility of the seal surface 12a is maintained. The sealing performance with respect to the valve seat 16 can be ensured. Moreover, the compressive stress by the outer edge 37c of the recessed part 37 can be made appropriate.

  In the state before the seal member 12 is attached in the recess 37, the diameter (outside dimension) D2 of the portion that contacts the outer edge 37c when attached in the recess 37 is the diameter of the outer edge 37c of the recess 37 ( Inner dimension) It is larger than D1. That is, the recess 37 has an inner dimension smaller than the outer dimension of the portion on the seal surface 12 a side of the seal member 12 in a state before being attached to the recess 37. For this reason, when the seal member 12 is mounted in the recess 37, a portion in contact with the outer edge 37c is compressed in the radial direction, and a compressive stress in that direction is generated.

  Further, the end of the seal member 12 on the side inserted into the back of the recess 37 and the bottom surface 37a of the recess 37 have the same diameter D. In other words, the difference between the diameter of the seal member 12 and the diameter of the recess 37 gradually increases from the back side of the recess 37 toward the opening side. For this reason, the stress generated in the seal member 12 is greatest at the portion sandwiched by the outer edge 37 c of the recess 37. Therefore, since the compressive stress due to the outer edge 37c of the recess 37 is transmitted to the back side of the seal member 12, the seal surface 12a is unlikely to swell. Further, no compressive stress is generated on the seal surface 12a and the opposite end surface (end surface on the back side of the recess 37) 12b.

  The valve 10 of the present embodiment includes bulging suppression means 40 that suppresses the expansion of the position along the valve seat 16 of the seal surface 12a when the seal surface 12a is seated on the valve seat 16. This point will be described in comparison with a comparative example. In the comparative example, the seal member 42 is attached to the recess 43 without being compressed. For this reason, as shown in FIG. 4A, when the seal surface 42a is seated on the valve seat 16, the position along the valve seat 16 is reduced as the seal surface 42a is depressed by being pressed by the valve seat 16. Swell. In the state where the seal surface 42a is seated, the width W2 of the pressure receiving surface is defined by the width between the side surfaces of the valve seat 16 with which the swelled seal surface 42a contacts. The amount of swelling of the seal surface 42a varies depending on the ambient temperature, the deterioration state of the seal surface 42a, and the like. Therefore, if the bulge amount of the seal surface 42a is large, the fluctuation of the bulge amount also becomes large, so that the fluctuation of the pressure receiving area (valve opening pressure) becomes large and disturbs the stable operation of the valve.

  On the other hand, in the seal structure of the first embodiment, the compressive stress of the seal member 12 is particularly increased at a portion closer to the seal surface 12a than the end surface 12b on the back side among the portions located in the recess 37. . For this reason, as shown in FIG. 4B, even if compressive stress does not occur at the seal surface 12a close to the portion where the compressive stress is increased, the seal surface 12a is depressed by being pressed from the valve seat 16. The swelling of the sealing surface 12a is suppressed. For this reason, even if the sealing surface 12a is seated and swells along the valve seat 16, the amount of swelling is small. Therefore, there is little variation in the pressure receiving area.

  That is, in the seal structure of the valve 10 of the present embodiment, the bulge suppressing means that suppresses expansion of the position along the valve seat 16 of the seal surface 12a when the seal surface 12a of the seal member 12 is seated on the valve seat 16. 40 is provided. The bulge suppressing means 40 is constituted by a concave portion 37 to which the seal member 12 is attached. The recess 37 has an inner dimension D1 that is smaller than the outer dimension D2 of the part on the seal surface 12a side of the seal member 12 in a state before being attached. The inner dimension D1 of the concave portion 37 is a dimension of a portion that is in contact with a portion on the seal surface 12a side (a portion having an outer dimension D2) when the seal member 12 is attached. In addition, the bulging suppression means 40 is a portion closer to the seal surface 12a than the end surface 12b on the back side of the seal member 12 and a direction perpendicular to the moving direction of the holding body 34 at a portion closer to the back side than the seal surface 12a. It is comprised so that the compressive stress of this may be generated. Further, the bulge suppressing means 40 is configured to increase the stress at the site on the seal surface 12a side as compared with the site on the back side of the seal member 12. Further, the bulge suppressing means 40 increases the stress by compressing a portion of the seal member 12 on the seal surface 12a side from the outside. Further, the bulge suppressing means 40 also suppresses the bulge of the surface other than the seal surface 12a. That is, the inner peripheral surface 37 b of the recess 37 is in contact with the side surface 12 c of the seal member 12, and the bottom surface 37 a of the recess 37 is in contact with the end surface 12 b on the back side of the seal member 12. Thereby, as for the sealing member 12, it is suppressed that surfaces other than the sealing surface 12a swell.

  By providing the bulging suppression means 40 in this way, the width W3 of the pressure receiving surface at the time of sitting becomes larger than the width W2 in the comparative example. In other words, the rate at which the pressure receiving area decreases when the seal surface 12a is seated is reduced. Therefore, the variation in the pressure receiving area is suppressed, and the valve 10 has a small variation in the valve opening pressure.

  Further, the bulge suppressing means 40 is configured to function also as an engaging portion that prevents the seal member 12 from being detached from the concave portion 37. That is, the diameter (internal dimension) D1 at the outer edge 37c of the recess 37 is formed to be smaller than the diameter D at the back end face of the seal member 12. Thereby, the sealing member 12 is prevented from coming off from the recess 37.

  As described above, in the present embodiment, the bulging suppressing means 40 suppresses the bulging of the position along the valve seat 16 of the sealing surface 12a of the sealing member 12. For this reason, when the seal surface 12 a is seated on the valve seat 16, it is possible to suppress a change in the area of the pressure receiving surface defined by the valve seat 16. Therefore, while ensuring the sealing performance between the seal surface 12a and the valve seat 16, excessive deformation of the seal surface 12a can be suppressed to suppress variation in the pressure receiving area.

  When the surface other than the seal surface 12a of the seal member 12 swells when the seal surface 12a is seated on the valve seat, the entire seal member 12 is deformed so that the seal surface 12a moves away from the valve seat 16. . For this reason, when the coil spring 20 is used to generate a force for pressing the seal member 12 against the valve seat 16, the amount of elongation of the coil spring 20 is affected. On the other hand, in 1st Embodiment, the bulging suppression means 40 has also suppressed that surfaces other than the seal surface 12a bulge. For this reason, it is possible to prevent the extension amount of the coil spring 20 from greatly changing from the design value. Therefore, the set load of the coil spring 20 can be maintained at a predetermined value, and the force necessary for separating the seal surface 12a from the valve seat 16 can be stabilized. That is, since excessive deformation of the entire seal member 12 can be suppressed, the length of the coil spring 20 can be prevented from changing from the initial value, and the set load of the coil spring 20 can be stabilized. . In this respect as well, fluctuations in the pressure receiving area can be suppressed. Note that the change in the pressure receiving area has a greater influence on the valve opening performance than the change in the length of the coil spring 20 from the initial value. For this reason, even if the bulging suppression means 40 is a structure which does not suppress bulging of surfaces other than the seal surface 12a, the valve opening performance can be improved.

  Moreover, in this embodiment, the bulging suppression means 40 raises the stress of the site | part on the seal surface 12a side rather than the site | part on the opposite side to the seal surface 12a in the sealing member 12. FIG. For this reason, the swelling toward the valve seat 16 side can be suppressed in the entire seal surface 12a. That is, when the stress of not only the seal surface 12a side but also the portion of the seal member 12 opposite to the seal surface 12a (back side) is increased, when the seal surface 12a is seated on the valve seat 16, Stress is less likely to act toward the back side of the seal member 12. For this reason, stress acts toward the seal surface 12a, and as a result, the seal surface 12a tends to be in a swelled state. On the other hand, as in the present embodiment, if the stress at the back side of the seal member 12 is not increased, the stress toward the back side of the seal member 12 when the seal surface 12a is seated on the valve seat 16. Becomes easier to act. For this reason, the seal surface 12a is unlikely to swell. Therefore, fluctuations in the pressure receiving area can be further suppressed. Moreover, the excessive deformation | transformation in the sealing member 12 whole can be suppressed.

  Moreover, in this embodiment, the bulging suppression means 40 is comprised so that stress may be raised by compressing the site | part by the side of the sealing surface 12a of the sealing member 12 from the outer side. For this reason, excessive deformation of the seal surface 12a can be suppressed while the configuration for applying stress to the seal member 12 is not complicated. Therefore, fluctuations in the pressure receiving area can be suppressed with a simple configuration.

  Moreover, in this embodiment, the bulging suppression means 40 is comprised by the recessed part 37 which has an inner dimension smaller than the outer dimension of the site | part by the side of the sealing surface 12a of the sealing member 12 in the state before attaching to the recessed part 37. FIG. For this reason, the effect by the bulging suppression means 40 can be stably exhibited with a simple configuration that only determines the dimensions of the component parts. Therefore, the deformation amount of the seal surface 12a can be stabilized. And since the compressive stress of the direction orthogonal to the moving direction of the holding body 34 can be generated in the sealing member 12, the dent of the sealing surface 12a when pressed by the valve seat 16 can be suppressed.

  Further, in the present embodiment, the bulging suppressing means 40 causes the seal member 12 to generate stress at a site closer to the seal surface 12a than the end surface 12b on the back side and further to the back side than the seal surface 12a. It is configured. For this reason, the excessive deformation | transformation of the sealing member 12 can be suppressed, ensuring the moderate softness | flexibility of the sealing surface 12a so that sealing performance can be ensured. And since the stress of the site | part by the side of the seal surface 12a can be raised, the fluctuation | variation of a pressure receiving area can be suppressed. Further, since excessive stress is not generated on the seal surface 12a itself, the seal surface 12a can be prevented from undulating and the pressure receiving area can be set more accurately.

  In the present embodiment, the sealing surface 12 a protrudes toward the valve seat 16 with respect to the outer edge 37 c of the recess 37. For this reason, while the recessed part 37 can generate | occur | produce a stress in the site | part which removed the sealing surface 12a of the sealing member 12, the moderate softness | flexibility of the sealing surface 12a can be ensured so that sealing performance can be ensured. Stress can be generated at a site closer to the seal surface 12a than the end surface 12b on the back side of the seal member 12 and on the side of the end surface (back end surface 12b) on the opposite side of the seal surface 12a. Therefore, stress can be generated at a desired site with a simple configuration. In addition, even if the seal member 12 is worn at the contact portion with the valve seat 16, it is possible to avoid the outer edge 37c of the recess 37 from contacting the casing outside the valve seat 16.

  In the present embodiment, the bulge suppressing means 40 is also configured to function as an engaging portion that prevents the seal member 12 from being detached from the recess 37. For this reason, simplification of the structure for preventing the sealing member 12 from coming off the holding body 34 can be achieved. Therefore, a sealing function can be ensured with a simple configuration.

  Further, in this embodiment, the seal member 12 has a circular cross section parallel to the seal surface 12a, and the bulge suppressing means 40 applies the compressive stress at the site on the seal surface 12a side from the outer periphery of the circular shape of the seal member 12. For this reason, the direction of stress generated in the seal member 12 is uniform, and excessive stress concentration can be prevented from occurring in the seal member 12. Therefore, the lifetime of the seal member 12 can be increased.

  In this embodiment, the seal member 12 is inserted into the recess 37 from the opening side (valve seat 16 side) of the recess 37 and attached to the recess 37. For this reason, the structure which suppresses the excessive deformation | transformation of the sealing member 12 and suppresses the fluctuation | variation of a pressure receiving area by a simple method can be obtained easily.

  In the first embodiment, the specific shape of the opening edge (outer edge 37c) of the recess 37 is not mentioned, but the cross section of the opening edge of the recess 37 is rounded as shown in FIG. It may be formed in a different shape. By doing so, it is possible to prevent the sealing member 12 from being damaged by the outer edge 37 c of the recess 37, while generating a compressive stress in the direction orthogonal to the moving direction of the holding body 34 on the sealing member 12. Further, when the sealing member 12 is inserted into the recess 37 and attached, the sealing member 12 can be easily inserted into the recess 37. In addition, when the inclination of the side surface of the recessed part 37 is not attached so much (closely perpendicular), or when the sealing member 12 does not protrude from the recessed part 37 as shown in FIG. 6, the opening edge (outer edge 37c). The cross section may be angular.

  In 1st Embodiment, although the sealing member 12 demonstrated the example in which the longitudinal cross section was formed in the trapezoid shape, it is not restricted to this. Alternatively, as shown in FIG. 7, in a state before being attached to the recess 37, the seal member 12 may be formed in a rectangular shape in the longitudinal section. In this case, the seal member 12 preferably has a width corresponding to the width on the back side of the recess 37 (the width of the bottom surface 37a). And it is preferable that the site | part by the side of the sealing surface 12a is compressed by the site | part by the side of the opening end of the recessed part 37. FIG. The seal member 12 may or may not protrude from the outer edge 37 c of the recess 37.

  In 1st Embodiment, although the longitudinal cross-section of the recessed part 37 becomes trapezoid, it is not restricted to this. For example, as shown in FIG. 8, the longitudinal section of the recess 37 may be formed in a rectangular shape. In this case, the seal member 12 may be formed in a trapezoidal shape with the largest lateral width on the seal surface 12a. By arranging the seal surface 12a slightly protruding from the outer edge 37c of the concave portion 37, a compressive stress can be generated at a site on the seal surface 12a side and shifted from the seal surface 12a to the back side. . In this case, the opening edge (outer edge 37c) of the recess 37 may be rounded. Further, the sealing member 12 may be formed in such a size that the sealing surface 12a and the end surface of the holding body 34 are flush with each other. In this case, the stress at the seal surface 12a is the highest.

(Second Embodiment)
FIG. 9 shows a second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same component as 1st Embodiment here, and the detailed description is abbreviate | omitted.

  In the first embodiment, the stress generated in the seal member 12 by the bulge suppressing means 40 is gradually reduced from the seal surface 12a side to the back end surface 12b side. On the other hand, in the second embodiment, the seal member is used. 12 is configured to generate stress only at the end portion on the seal surface 12a side.

  Specifically, the seal member 12 has a concave ring portion 12d formed on the outer peripheral portion of the end portion on the seal surface 12a side. On the other hand, a convex portion 37 d that protrudes inward in the radial direction is formed at the opening edge of the concave portion 37. The convex portion 37d is formed in an annular shape. The diameter D2 of the seal surface 12a of the seal member 12 before being attached to the recess 37 is formed larger than the diameter D1 of the outer edge 37c of the recess 37 of the holding body 34. On the other hand, in other locations, the diameter of the seal member 12 and the diameter of the recess 37 are both the same as the diameter D. For this reason, the seal member 12 is compressed by the concave portion 37 of the holding body 34 in the portion where the concave ring portion 12d which is the portion on the seal surface 12a side is formed. With this configuration, the bulge suppressing means 40 is configured.

  Other configurations, functions, and effects are the same as those in the first embodiment, although explanations thereof are omitted.

(Third embodiment)
FIG. 10 shows a third embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same component as 1st Embodiment here, and the detailed description is abbreviate | omitted.

  In 1st Embodiment, it has the structure which raises the stress in the site | part which shifted | deviated to the back | inner side from the seal surface 12a, suppressing the generation | occurrence | production of the stress in the seal surface 12a because the seal member 12 protrudes from the recessed part 37. . On the other hand, in the third embodiment, the seal member 12 does not protrude from the recess 37, and the stress is increased most at the intermediate portion in the thickness direction.

  Specifically, as shown in FIG. 10, the opening end of the recess 37 (the outer edge 37c of the recess 37) has a rounded shape. The side surface 37b of the recess 37 other than the opening end is parallel to the thickness direction of the seal member 12 (the moving direction of the holding body 34). For this reason, the width D1 at the opening edge of the recess 37 is larger than the width D3 on the back side of the recess 37.

  On the other hand, the seal member 12 has a thickness H that matches the depth H of the recess 37. The seal member 12 has a trapezoidal longitudinal cross section, and the diameter of the seal surface 12a has a diameter corresponding to the diameter D1 of the opening edge of the recess 37. Further, in the sealing member 12, the diameter of the end surface 12b opposite to the sealing surface 12a has a diameter corresponding to the diameter D3 on the back side of the recess 37. With this configuration, the seal member 12 attached to the concave portion 37 is compressed by the side surface 37b of the concave portion 37 other than the opening edge portion, and spreads in a flare shape along the curved opening edge portion (outer edge 37c). The seal member 12 is a site on the seal surface 12a side, and compressive stress is generated at a position shifted from the seal surface 12a to the back side. On the other hand, no compressive stress is generated on the seal surface 12a and the back end surface 12b. Note that the seal surface 12a may protrude from the recess 37.

  FIG. 11 shows an example in which a compressive stress is generated at a portion close to the seal surface 12a by providing a bulging portion 37e on the inner peripheral surface of the recess 37. The seal member 12 has a rectangular longitudinal section, and the inner peripheral surface of the recess 37 includes a portion having a shape corresponding to the shape of the seal member 12 and a bulging portion 37e bulging inward from the portion. ing. The bulging portion 37e is formed at a position closer to the opening edge (outer edge 37c) than the inner surface (bottom surface) 37a of the recess 37. Accordingly, the stress of the seal member 12 is increased at the intermediate portion on the side close to the seal surface 12a, while no compressive stress is generated on the seal surface 12a and the back end surface 12b. Note that the seal surface 12a may protrude from the recess 37.

  FIG. 12 is an example when the longitudinal section of the recess 37 is formed in a rectangular shape. In this case, the seal member 12 is formed in a hexagonal shape in the longitudinal section, and the diameter of the portion closer to the seal surface 12a than the end surface 12b on the back side is larger than the diameter on the back side of the seal surface 12a. It is formed as follows. In this case, the diameters of the seal surface 12 a and the back end surface 12 b are the same as the diameter of the recess 37. The diameter of the intermediate portion in the thickness direction of the seal member 12 is larger than the diameter of the recess 37. Even in this case, the seal member 12 is increased in stress at the intermediate portion on the side close to the seal surface 12a, whereas no compressive stress is generated on the seal surface 12a and the end surface 12b on the back side. Note that the seal surface 12a may protrude from the recess 37.

  Other configurations, functions, and effects are the same as those in the first embodiment, although explanations thereof are omitted.

(Fourth embodiment)
FIG. 13 shows a fourth embodiment of the present invention. Here, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the first embodiment, the bulging suppression means 40 also serves as an engaging portion that prevents the seal member 12 from being detached from the recess 37. On the other hand, for example, in the fourth embodiment, an engaging portion 45 is provided separately from the bulge suppressing means 40.

  The engaging portion 45 is constituted by a flange-shaped portion 12 e provided on the end surface 12 b on the back side of the seal member 12 and a groove portion 37 f formed on the bottom surface of the concave portion 37. By fitting the key-shaped part 12e into the groove part 37f, the seal member 12 is prevented from coming off.

  The longitudinal cross-sectional shapes of the seal member 12 and the recess 37 are rectangular, but the diameter of the seal member 12 is larger than the diameter of the recess 37. For this reason, radial compressive stress is generated in the seal member 12 attached to the recess 37.

  As shown in FIG. 14, the engaging portion 45 may be provided on the side surface of the seal member 12 and the side surface of the recess 37. The engaging portion 45 is configured by a groove portion 12 f formed on the outer peripheral surface of the seal member 12 and a protruding portion 37 g formed on the inner peripheral surface of the concave portion 37. The groove portion 12f is formed at an intermediate portion in the thickness direction of the seal member 12. The portion of the seal surface 12a side with respect to the groove portion 12f has a larger diameter than the portion of the back end surface 12b side with respect to the groove portion 12f. Thereby, in the seal member 12, a compressive stress is generated at a site on the seal surface 12a side with respect to the groove 12f. In addition, the site | part by the side of the sealing surface 12a may be settled in the recessed part 37, and may protrude from the outer edge 37c of the recessed part 37. FIG.

  Other configurations, functions, and effects are the same as those in the first embodiment, although explanations thereof are omitted.

(Fifth embodiment)
15 (a) and 15 (b) show a fifth embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same component as 1st Embodiment here, and the detailed description is abbreviate | omitted.

  In the first embodiment, the seal member 12 is simply attached to the concave portion 37 of the holding body 34. However, in the fifth embodiment, the shape of the holding body 34 to which the seal member 12 is attached is changed to change the seal member. 12 generates a compressive stress. Specifically, as shown in FIG. 15A, the longitudinal cross-sectional shape of the seal member 12 matches the vertical cross-sectional shape of the recess 37, so when the seal member 12 is attached to the recess 37, No compressive stress is generated in the seal member 12. That is, at this time, the bulging suppression means 40 is not provided. Then, the seal member 12 is compressed by crushing and deforming the end portion on the bottom 29 side of the holding body 34 to which the seal member 12 is mounted from the outside. In this case, the seal member 12 is crushed so as to be closer to the seal surface 12a side. As a result, stress is generated at the site of the seal member 12 on the seal surface 12a side. That is, the bulging suppression means 40 is configured by the end portion of the holding body 34 crushed from the outside. As shown in FIG. 16, if the notch 34 c is formed on the end surface of the holding body 34 that faces the bottom 29, the holding body 34 can be easily crushed and deformed.

  Other configurations, functions, and effects are the same as those in the first embodiment, although explanations thereof are omitted.

(Sixth embodiment)
FIG. 17 shows a sixth embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same component as 1st Embodiment here, and the detailed description is abbreviate | omitted.

  In the first embodiment, the bulge suppressing means 40 that suppresses the bulging of the seal surface 12a by generating a compressive stress on the seal member 12 is provided. On the other hand, in the sixth embodiment, bulge suppressing means 40 that suppresses the swelling of the seal surface 12a by generating a tensile stress on the seal member 12 is provided.

  The seal member 12 includes a main body portion 12g having a diameter corresponding to the diameter of the concave portion 37, and an extension portion 12h extending from the outer periphery of the seal surface 12a in the main body portion 12g. The bulge suppressing means 40 has a fastening portion 40 a that fixes the extended portion 12 h to the holding body 34 in a state where the extended portion 12 h of the seal member 12 is pulled. Since the extended portion 12h is connected to the end portion of the main body portion 12g on the seal surface 12a side, tensile stress can be generated on the seal surface 12a. The main body portion 12 g is accommodated in the concave portion 37, and the side surface 12 c of the main body portion 12 g is in contact with the inner peripheral surface 37 b of the concave portion 37. For this reason, the bulging suppression means 40 can hold | maintain the main-body part 12g stably, also suppressing that surfaces other than the sealing surface 12a of the sealing member 12 swell.

  As illustrated in FIG. 18, the extending portion 12 h of the seal member 12 may be configured to extend from a portion of the main body portion 12 g that is slightly displaced from the seal surface 12 a. The bulge suppressing means 40 including the extending portion 12h generates tensile stress in a portion closer to the seal surface 12a than the end surface 12b on the back side of the main body portion 12g and on the back side from the seal surface 12a. It is configured as follows. For this reason, the excessive deformation | transformation of the sealing member 12 can be suppressed, ensuring the moderate softness | flexibility of the sealing surface 12a so that sealing performance can be ensured. In addition, fluctuations in the pressure receiving area can be suppressed.

  As shown in FIG. 19, the main body portion 12 g of the seal member 12 may not be accommodated in the concave portion 37 of the holding body 34. In this case, the seal member 12 can be attached without providing the concave portion 37 in the holding body 34. By providing the taper portion at the connection portion between the side surface 12c of the main body portion 12g and the extension portion 12h, it is possible to suppress stress from being concentrated on the connection portion as the extension portion 12h is pulled.

  20 does not suppress the deformation of the side surface 12c of the main body 12g in the seal member 12 at the inner peripheral surface 37b of the recess 37 as in FIGS. 17 and 18, but generates stress on the side 12c of the main body 12g. To suppress deformation. Specifically, the recessed part 37 formed in the holding body 34 does not have the inner peripheral surface 37b facing the side surface 12c of the main body part 12g. The recessed portion 37 is recessed from the opening edge (outer edge 37c) in a curved shape and is connected to the flat bottom surface 37a. The inner peripheral surface 37 h of the outer peripheral portion that is concavely curved in the concave portion 37 presses the outer peripheral portion of the back end surface 12 b in the main body portion 12 g of the seal member 12 in the axial direction of the seal member 12 (the moving direction of the holding portion 34). Thereby, compressive stress can be produced in the side surface 12c of the main-body part 12g of the sealing member 12, and a deformation | transformation of the side surface 12c can be suppressed. That is, the seal member 12 is suppressed from expanding other than the seal surface 12a as well as the surface other than the seal surface 12a. In addition, since the compressive stress is not produced in the center part of the radial direction of the main-body part 12g, the deformation amount as the whole sealing member 12 is suppressed.

  Other configurations, functions, and effects are the same as those in the first embodiment, although explanations thereof are omitted.

(Seventh embodiment)
FIG. 21 shows a seventh embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same component as 1st Embodiment here, and the detailed description is abbreviate | omitted.

  In the first embodiment, the bulge suppressing means 40 that suppresses the bulging of the seal surface 12a by generating stress on the seal member 12 is provided. On the other hand, in the seventh embodiment, the bulge suppressing means 40 that suppresses the swelling of the seal surface 12a without causing stress on the seal member 12 is provided.

  The bulge suppressing means 40 includes a pressing member 40 b having a pressing portion 40 c that is located on the radially inner side of the valve seat 16 and faces the sealing surface 12 a of the sealing member 12. The pressing member 40b includes a substrate portion 40d formed so that the pressing portion 40c protrudes, and a support portion 40e that supports the substrate portion 40d on the holding body 34. A through hole 12 i is formed in the radial center of the seal member 12, and the support portion 40 e is inserted into the through hole 12 i and fixed to the bottom surface 37 a of the concave portion 37 of the holding body 34.

  The seal member 12 is held in the recess 37 of the holding body 34 so that no stress is generated. When the sealing surface 12a of the sealing member 12 is seated on the valve seat 16, the pressing portion 40c of the pressing member 40b presses the sealing surface 12a so that the sealing surface 12a does not swell.

  Other configurations, functions, and effects are the same as those in the first embodiment, although explanations thereof are omitted.

(Eighth embodiment)
22 (a) and 22 (b) show an eighth embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same component as 1st Embodiment here, and the detailed description is abbreviate | omitted.

  In the first embodiment, the seal member 12 is inserted from the opening of the recess 37 and fixed to the holding body 34. On the other hand, in the eighth embodiment, the seal member 12 is inserted from an opening other than the opening of the recess 37 and fixed to the holding body 34.

  Specifically, as shown in FIG. 22A, a communication hole 34 d communicating with the space in the recess 37 is formed on the side wall of the holding body 34. The communication hole 34d opens to the outer surface of the side wall of the holding body 34, and the seal member 12 can be inserted into the recess 37 through the opening of the communication hole 34d. As shown in FIG. 22B, after the seal member 12 is inserted, the communication hole 34 d is blocked by the plug portion 47. The seal member 12 may be configured to be compressed by the plug portion 47.

  In addition, as shown in FIG. 23, the holding body 34 may be divided into two, and the sealing member 12 may be sandwiched between the both divided members 34e and 34e from the lateral direction. Further, the communication hole 34d is not limited to the configuration connected to the side surface side of the concave portion 37, and may be configured to be connected to the bottom surface 37a side of the concave portion 37 as shown in FIGS. In this case, the valve rod 35 is connected to the plug portion 47.

  Other configurations, functions, and effects are the same as those in the first embodiment, although explanations thereof are omitted.

DESCRIPTION OF SYMBOLS 10 Valve 12 Seal member 12a Seal surface 12b End surface 16 Valve seat (an example of a seal seat)
20 Coil spring 34 Holding body 37 Concave portion 37c Outer edge 40 Swelling suppression means 45 Engagement portion

Claims (15)

A seal member having a seal surface, the seal member being movable between a position where the seal surface is seated on a seal seat and a position where the seal surface is separated from the seal seat;
A swell structure that includes a bulge restraining means that restrains a bulge of a position of the seal surface along the seal seat when the seal surface of the seal member is seated on the seal seat. The seal structure according to claim 1,
The said swelling suppression means is a seal structure comprised so that it may also suppress that surfaces other than the said seal surface in the said seal member swell when the said seal surface of the said seal member seats on the said seal seat. The seal structure according to claim 1 or 2,
The bulge suppressing means is a seal structure configured to increase the stress at a site on the seal surface side rather than a site on the side opposite to the seal surface in the seal member. The seal structure according to claim 3,
The said swelling suppression means is a sealing structure comprised so that the said stress may be raised by compressing the site | part by the side of the sealing surface of the said sealing member from the outer side. The seal structure according to claim 4,
The bulge suppressing means is a recess formed in the holding body that holds the seal member, and is attached to the recess at least at a site on the seal surface side in a direction orthogonal to the moving direction of the holding body. The seal structure comprised by the said recessed part which has an internal dimension smaller than the external dimension of the site | part of the said seal surface side of the said seal member in the state of this. In the seal structure according to any one of claims 3 to 5,
The bulge suppressing means generates the stress at a portion that is closer to the seal surface than the end surface opposite to the seal surface of the seal member and is closer to the end surface opposite to the seal surface. The seal structure is configured as follows. The seal structure according to claim 5,
The seal structure, wherein the seal surface protrudes closer to the seal seat than the opening end of the recess. The seal structure according to claim 5 or 7,
The said swelling suppression means is a seal structure comprised so that it may function also as an engaging part which prevents that the said sealing member remove | deviates from the said recessed part. The seal structure according to claim 5 or 7,
The said recessed part is a sealing structure provided with the engaging part which prevents that the said sealing member remove | deviates from the said recessed part. The seal structure according to claim 5 or 7,
A seal structure in which an open end of the concave portion is rounded. The seal structure according to any one of claims 3 to 10,
The seal member has a circular cross-sectional shape parallel to the seal surface, and the bulge suppressing means is configured to increase the stress at a portion on the seal surface side from the entire circular periphery of the seal member. The seal structure. The seal structure according to claim 5 or 7,
The concave portion has a sealing structure in which the opening end side has a truncated cone shape with a small diameter. The seal structure according to any one of claims 3 to 12,
The seal member has a seal structure in which the seal surface side has a truncated cone shape with a small diameter. The seal structure according to any one of claims 1 to 13,
A seal seat on which the seal surface of the seal member is seated;
A biasing member that biases the seal member in a direction in which the seal surface is seated on the seal seat;
A valve in which a surface pressed by a fluid flowing in a space defined by the seal seat among the seal surfaces becomes a pressure receiving surface for moving the seal member. It is a manufacturing method of the seal structure according to claim 5 or 7,
The recess is open to the seal seat side,
A method for manufacturing a seal structure, wherein the seal member is attached to the recess from the seal seat side.

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