JP2019206995A - Control valve - Google Patents

Abstract

To provide a control valve capable of suppressing leakage of fluid even when a parting line exists on a valve element.SOLUTION: A control valve 100 includes a body 200, and a valve element 400 attachable to and detachable from a valve seat 232 and opening and closing a valve portion. The valve element 400 includes a main body 420 provided with a recessed fitting portion 422 along an outer periphery, and a seal ring 440 fitted to the fitting portion 422 and attachable to and detachable from the valve seat 232. The fitting portion 422 has a first side surface and a second side surface opposed to each other in an axial direction of the valve element 400, the seal ring 440 has a first end surface opposed to the first side surface and a second end surface opposed to the second side surface, and the end surface at least on a low pressure side of the first end surface and the second end surface has an annular contact portion kept into contact with the opposed side surface in a linear contact manner.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a control valve having a seal ring in a valve body.

  Conventionally, for example, a flow rate control valve that controls the flow rate of a gas water heater (hereinafter, simply referred to as “control valve”) is known. (For example, refer to Patent Document 1). Such a control valve includes a seal member that is provided in the valve body and seals the valve portion in contact with the valve seat in the closed state. This seal member is, for example, a rubber seal ring, is dimensioned to fit in an annular groove provided in the main body of the valve body, and is fixed by a binding force.

JP 2005-282649 A

  Generally, such a main body is obtained by injection molding of a resin material. At the time of molding, a plurality of molds constituting a so-called split mold are used. Therefore, a parting line is formed in the molded body along the boundary lines of the plurality of molds.

  In the conventional structure, this parting line exists on the surface where the seal ring and the main body come into contact, so there is a slight gap between the main body and the seal ring in the vicinity of the parting line, causing minute fluid leakage. It was. For this reason, in the case of a control valve that does not allow slight leakage, it is necessary to cut the main body to remove the step due to the parting line, resulting in high costs.

  The present invention has been made in view of such problems, and one of its purposes is to provide a control valve capable of suppressing fluid leakage even when a parting line is present in the main body of the valve body. is there.

  A control valve according to an aspect of the present invention includes a body having an introduction port for introducing fluid from the upstream side, a derivation port for guiding fluid to the downstream side, and a valve seat provided in a passage connecting the introduction port and the derivation port. And a valve body that opens and closes the valve portion by attaching and detaching to the valve seat, and an actuator that opens and closes the valve portion by driving the valve body in the axial direction, and the valve body has a concave fitting portion along the outer periphery. And a seal ring that is fitted to the fitting portion and is attached to and detached from the valve seat. The fitting portion includes a first side surface and a second side surface that face each other in the axial direction of the valve body. And the seal ring has a first end surface facing the first side surface and a second end surface facing the second side surface, and at least of the first end surface and the second end surface The end surface which becomes a low voltage | pressure side has the cyclic | annular contact part contact | abutted by the line contact mode with respect to the opposing side surface.

  A control valve according to another aspect of the present invention includes an introduction port that introduces fluid from the upstream side, a derivation port that guides fluid to the downstream side, and a valve seat that is provided in a passage that connects the introduction port and the derivation port. A valve body that opens and closes the valve portion by attaching to and detaching from the valve seat; and an actuator that opens and closes the valve portion by driving the valve body in the axial direction, and the valve body has a concave fitting along the outer periphery. A seal ring that is fitted to the fitting portion and is attached to and detached from the valve seat, and the seal ring is in a line contact mode with the fitting portion on a surface facing the fitting portion. It has an annular contact portion that contacts.

  A control valve according to another aspect of the present invention includes an introduction port that introduces fluid from the upstream side, a derivation port that guides fluid to the downstream side, and a valve seat that is provided in a passage that connects the introduction port and the derivation port. A valve body that opens and closes the valve portion by attaching to and detaching from the valve seat; and an actuator that opens and closes the valve portion by driving the valve body in the axial direction, and the valve body has a concave fitting along the outer periphery. A main body having a peripheral portion and a seal ring that is fitted to the fitting portion and is attached to and detached from the valve seat. The fitting portion includes a first side surface and a second side surface that face each other in the axial direction of the valve body. And the seal ring has a first end face facing the first side face and a second end face facing the second side face, and at least of the first end face and the second end face It includes an annular low-rigidity portion whose cross section is narrowed toward one end surface, and the height of the portion where the low-rigidity portion is located But it is set to be larger than the distance between the first and second sides before fitting of the fitting portion.

  ADVANTAGE OF THE INVENTION According to this invention, even if a parting line exists in a valve body, the control valve which can suppress a fluid leak can be provided.

It is sectional drawing showing the whole structure of the control valve which concerns on 1st Embodiment. It is a perspective view of a valve body. It is a seal ring in this embodiment. It is sectional drawing of a fitting part vicinity. Fig.5 (a) is AA sectional drawing in FIG.4 (b). FIG. 5B is a BB cross section in FIG. Fig.6 (a) is CC sectional drawing in FIG.5 (b). FIG. 6B is a view showing the outer periphery of the cross section of the seal ring in FIG. Fig.7 (a) is CC sectional drawing at the time of fitting the seal ring of a comparative example. FIG.7 (b) is a figure which shows the cross-sectional outer periphery of a seal ring among Fig.7 (a). It is sectional drawing of the modification of the seal ring of 1st Embodiment. FIG. 9A is a central sectional view of a seal ring used in the second embodiment. FIG. 9B is a cross-sectional view of the vicinity of the fitting portion when the seal ring in the second embodiment is used. FIG. 10A is a central longitudinal sectional view of a seal ring provided with annular beads at the upper end and the lower end. FIG.10 (b) is sectional drawing of the fitting part vicinity at the time of making the seal ring of Fig.10 (a) fit. FIG. 11A is a central longitudinal cross-sectional view when a bead is provided on the inner peripheral surface of the seal ring. FIG.11 (b) is sectional drawing of the fitting part vicinity when the seal ring of Fig.11 (a) is fitted. FIG. 12A is a central longitudinal sectional view when an R portion is provided in the vicinity of the outer peripheral edge of the lower end surface of the seal ring instead of the taper. FIG. 12B is a cross-sectional view of the vicinity of the fitting portion when the seal ring of FIG. 12A is fitted.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, for the sake of convenience, the positional relationship between the structures may be expressed based on the illustrated state. In the following embodiments and modifications thereof, substantially the same components are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

[First Embodiment]
FIG. 1 is a cross-sectional view illustrating the overall configuration of a control valve 100 according to the first embodiment. The control valve 100 is a flow control valve used for a hot water supply apparatus. The control valve 100 includes a body 200, a drive unit 300, and a valve body 400.

  The body 200 has a first body 220 and a second body 240. The first body 220 includes a cylindrical main body 221, an introduction pipe part 222 provided continuously with a side portion of the main body 221, and a lead-out pipe part 226 provided continuously below the main body 221. The introduction pipe portion 222 is provided at a right angle to the side surface of the main body 221, and the lead-out pipe portion 226 is provided coaxially with the main body 221. The introduction pipe part 222 has an introduction port 224 for introducing hot water (fluid) from the upstream side, and the outlet pipe part 226 has a outlet port 228 for leading fluid to the downstream side. A valve hole 230 is formed in the boundary portion between the main body 221 and the outlet tube portion 226 by an inner peripheral portion thereof. A valve seat 232 is formed at the end of the valve hole 230. The valve body 400 and the valve seat 232 form a “valve portion” that opens or blocks a passage connecting the introduction port 224 and the outlet port 228. The fluid is introduced from the introduction port 224, passes through the valve portion, and is led out from the outlet port 228. When the valve body 400 is attached to or detached from the valve seat 232, the valve portion is opened and closed. The second body 240 has a stepped cylindrical shape, and its lower half is assembled to the first body 220 via an O-ring 241. A guide hole 242 that slidably supports the valve body 400 is formed on the inner peripheral surface of the second body 240.

The valve body 400 has a stepped cylindrical main body 420. Recessed fitting portions 422 and 423 are provided on the outer periphery of the lower end portion and the upper end portion of the main body 420, respectively. The fitting part 422 is fitted with a seal ring 440 for sealing the valve part. The seal ring 440 is made of a ring-shaped elastic body (for example, rubber). A seal ring 460 for sealing the sliding portion is fitted to the fitting portion 423. In this embodiment, an O-ring is used as the seal ring 460. The seal ring 440 is attached to and detached from the valve seat 232 to open and close the valve portion, and when the valve is closed, the sealing performance of the valve portion is ensured.
An elongated operating rod 120 is provided so as to penetrate the second body 240 and the valve body 400 in the axial direction, and the valve body 400 is supported from below at the lower end. Between the valve body 400 and the second body 240, a spring 140 (functioning as an “urging member”) that biases the valve body 400 in the valve closing direction is interposed. The upper end of the main body 420 is slidably supported by the guide hole 242. A plurality of leg portions 421 are supported at the lower end portion of the main body 420 so as to be supported while sliding in the valve hole 230. The valve body 400 can operate stably in the axial direction by sliding the lower end portion along the valve hole 230 and sliding the upper end portion along the guide hole 242.

  The drive unit 300 includes a motor 320 as an actuator and a worm gear 340. The worm gear 340 includes a worm 342 provided on the output shaft of the motor 320 and a worm wheel 344 that meshes with the worm 342. The actuating rod 120 forms the rotation axis of the worm wheel 344. An O-ring 245 as a “seal ring” is interposed between the second body 240 and the operating rod 120. Moreover, the housing 160 is attached so that the upper half part of the 2nd body 240 may be covered. The motor 320 and the worm gear 340 are accommodated in a space surrounded by the housing 160 and the second body 240.

  The worm wheel 344 has an upper stopper 346 projecting from the upper end surface thereof, and a lower stopper (not shown in the drawing) provided at the lower end surface thereof. The upper stopper 346 cooperates with a stopper protruding from the inside of the housing 160 to restrict one of the movable ranges in which the worm wheel 344 can rotate, that is, the upper limit of the lift of the valve body 400. The lower stopper cooperates with the stopper of the second body 240 to regulate the other lower movable range in which the worm wheel 344 can rotate, that is, the lower limit of lift of the valve body 400.

  A small-diameter male screw portion 348 is formed in the lower half portion of the worm wheel 344 and is screwed into a female screw portion 244 projecting from the second body 240. The rotational motion of the worm wheel 344 is converted into translational motion by the screw mechanism formed by the male screw portion 348 and the female screw portion 244. That is, when the worm wheel 344 is rotated by driving the motor 320, the operating rod 120 is translated in the axial direction together with the worm wheel 344.

  The valve body 400 is supported from below by a stopper 122 provided at the lower end portion of the operating rod 120, and is urged downward by a spring 140. On the other hand, a step portion 121 is provided on the upper portion of the operating rod 120. The worm wheel 344 is inserted into the operating rod 120 and is locked to the stepped portion 121. A stopper 124 is provided at the upper end of the operating rod 120, and the worm wheel 344 is assembled to the operating rod 120 so as to be sandwiched between the stepped portion 121 and the stopper 124. A sliding bearing 123 is interposed between the upper surface of the worm wheel 344 and the stopper 124. With such a structure, the translational motion (vertical movement) of the worm wheel 344 is transmitted to the operating rod 120, but the rotational motion is not transmitted. That is, the rotation of the worm wheel 344 is not transmitted to the valve body 400 via the operating rod 120. In the open state in which the valve body 400 is separated from the valve seat 232, the valve body 400 and the operating rod 120 are integrally displaced while being stretched, but when the valve body 400 is in the closed state in which the valve body 400 is seated on the valve seat 232, The valve body 400 and the operating rod 120 can be relatively displaced.

FIG. 2 is a perspective view of the valve body 400. FIG. 2A is a perspective view showing a state in which a part of the valve body 400 is cut away. FIG. 2B is an exploded perspective view of the valve body 400.
The seal ring 440 is a member for ensuring the sealing performance of the valve portion by the valve body 400 when the valve is closed. The sealing function of the seal ring 440 is particularly important because fluid is introduced from the inlet port 224, passes through the valve section, and is led out from the outlet port 228.
The main body 420 is obtained by injection molding of a resin material. When the main body 420 is molded, a plurality of molds constituting a split mold are used. The main body 420 is formed with a parting line 424 at the time of molding. The parting line 424 is formed so as to go around the longitudinal section of the main body 420 as shown in FIG. Hereinafter, the main body 420 and the seal ring 440 will be described in detail.

FIG. 3 is a diagram illustrating the seal ring 440. 3A is a perspective view of the seal ring 440 as viewed from below, and FIG. 3B is a central longitudinal sectional view of the seal ring 440. FIG.3 (c) is the Y section enlarged view of FIG.3 (b).
The seal ring 440 has a rectangular cross section, and an upper end surface 441 and a lower end surface 443 thereof correspond to a “first end surface” and a “second end surface”, respectively. The vicinity of the outer peripheral edge of the lower end surface 443 is a tapered surface 456 complementary to the valve seat 232. The valve body 400 is attached to and detached from the valve seat 232 at its tapered surface 456.
An annular bead 442 is provided on the lower end surface 443 of the seal ring 440. This bead 442 is less rigid than the rest of the seal ring 440. For this reason, the bead 442 may be particularly referred to as a “low rigidity portion”. The bead 442 functions as an “annular contact portion”.

FIG. 4 is a partially enlarged view corresponding to a portion X in FIG. FIG. 4A shows a cross section without the parting line 424. FIG. 4B shows a cross section on the parting line 424.
The seal ring 440 is fitted into the fitting portion 422 of the main body 420. The fitting portion 422 has an upper side 426, a lower side 428, and a bottom 430. The upper side surface 426 and the lower side surface 428 face each other in the axial direction of the valve body 400, and correspond to the “first side surface” and the “second side surface”, respectively. In the closed state, the seal ring 440 is seated on the valve seat 232. At this time, the upstream side of the valve portion has a high pressure and the downstream side has a low pressure. For this reason, the differential pressure between the upstream pressure and the downstream pressure acts on the seal ring 440. As shown in FIG. 4A, the seal ring 440 is in contact with the lower side surface 428 and the bottom surface 430 where there is no parting line 424.

  On the other hand, as shown in FIG. 4B, the seal ring 440 floats at the parting line 424 at the part where the parting line 424 exists in the fitting portion 422. That is, a gap is generated between the seal ring 440 and the lower side surface 428 in the vicinity of the apex of the parting line 424. Hereinafter, in particular, the vicinity of the parting line 424 will be described in detail with respect to a cross section that does not include the beads 442 and a cross section that includes the beads 442 in the seal ring 440.

  FIG. 5A is a diagram illustrating an AA cross section in FIG. 4B, that is, a cross section not including the bead 442. FIG. 5B is a view showing a cross section including the BB cross section in FIG. 4B, that is, a bead 442. The dotted line in FIG. 5 is a parting line width 425 indicating the width of the parting line 424. 5B indicates the base end of the parting line 424 (the portion connected to the flat bottom surface of the seal ring 440). The bead height BH indicates the distance between the flat surface and the apex of the bead 442.

  Due to the differential pressure between the upstream pressure and the downstream pressure, the lower end surface 443 of the seal ring 440 is pressed against the lower surface 428 of the fitting portion 422. However, as shown in FIG. 5A, the lower flat surface of the seal ring 440 is locally pushed up at the parting line 424 and floats. For this reason, a gap G is formed between the seal ring 440 and the lower side surface 428. This is because the seal ring 440 is not easily deformed locally on a flat surface, and the seal ring 440 cannot follow the slope of the parting line 424.

  On the other hand, as shown in FIG. 5B, a bead 442 is provided on the lower end surface 443 of the seal ring 440. Since the bead 442 has a small cross section, it has low rigidity and is easily deformed. The bead height BH is larger than the height of the parting line 424. Since the annular bead 442 contacts the lower side surface 428 in a line contact manner, the annular bead 442 can be in close contact with the parting line 424 with a high surface pressure without a gap. On the other hand, the seal ring 440 is compressed in the axial direction by the differential pressure between the upstream pressure and the downstream pressure. For this reason, in this embodiment, a gap is formed between the upper end surface 441 of the seal ring 440 and the upper side surface 426 of the fitting portion 422.

6A is a cross-sectional view taken along the line C-C in FIG. 5B, that is, a cross-sectional view in the vicinity of the top of the parting line 424. FIG. 6B is a diagram schematically illustrating a pressure distribution acting on the seal ring 440. A thick line region R1 represents a high pressure region, and a middle line region R2 represents a low pressure region.
FIG. 7 is a view showing a case where there is no bead as a comparative example of FIG. In the seal ring 500 of the comparative example, the material used is the same as that of the seal ring 440, and the size and shape are the same as those of the seal ring 440 except for the beads 442. FIG. 7A is a partially enlarged sectional view showing the periphery of the seal ring 500. FIG. 7B schematically shows the pressure distribution acting on the seal ring 500.

  6 and 7, the fluid is introduced from the right direction and led out downward. In the closed state, the seal ring 440 and the seal ring 500 are seated on the valve seat 232, respectively. The pressure from the fluid concerning the seal ring 440 and the seal ring 500 at this time will be described.

  First, the pressure applied to the seal ring 440 in this embodiment will be described. As shown in FIG. 6A, a gap is formed between the fitting portion 422 and the seal ring 440 at a location where the vicinity of the parting line 424 is a flat surface. For this reason, the high-pressure fluid on the upstream side wraps around the seal ring 440 along the parting line 424. However, since the gap is closed at the bead 442, the fluid can be blocked. As a result, the pressure distribution as shown in FIG. Since the lower end surface 443 has a low pressure with respect to the upper end surface 441 of the seal ring 440, a downward differential pressure acts on the seal ring 440. As a result, the bead 442 is firmly attached to the lower side surface 428 even at the position of the parting line 424, and fluid leakage is suppressed.

  Next, the pressure applied to the seal ring 500 of the comparative example will be described. As shown in FIG. 7A, the seal ring 500 is not provided with beads. Therefore, the high-pressure fluid on the upstream side wraps around the seal ring 440 along the parting line 424 and passes through the valve portion as it is. At this time, the pressure distribution is as shown in FIG. Since the differential pressure in the downward direction is small in the seal ring 440 and there is no low rigidity portion to be pressed, the gap along the parting line 424 cannot be closed. As a result, fluid leaks from the upstream side to the downstream side.

  As described above, the seal ring 440 of the present embodiment includes the low-rigidity bead 442 on the end surface (the lower end surface 443 in the present embodiment) on the low pressure side of the upper end surface 441 and the lower end surface 443. For this reason, even if the valve body 400 has the parting line 424, the bead 442 is brought into close contact with the lower side surface 428 when the valve is closed, and fluid leakage can be prevented. The bead height BH may be appropriately designed so that no fluid leaks when the valve is closed according to the height of the parting line 424, the rigidity of the resin material used for the seal ring 440, or the like. When the rigidity of the resin material itself is relatively low, the bead height BH may be equal to or smaller than the height of the parting line 424.

FIG. 8 is a central longitudinal sectional view showing a seal ring according to a modification. FIG. 8A shows a first modification, and FIG. 8B shows a second modification. The seal ring 444 of the first modification has a tapered portion 445 whose transverse section is narrowed toward the lower end surface. The tip of the taper portion 445 is an annular low rigidity portion. Even when such a seal ring 444 is used, the low-rigidity portion is deformed and is brought into close contact with the parting line 424, so that fluid leakage can be suppressed in a closed state.
On the other hand, the seal ring 446 of the second modified example includes another bead 447 on the radially inner side of the bead 442. By setting it as such a double seal structure, sealing performance can be improved more.

[Second Embodiment]
The second embodiment differs from the first embodiment in the direction of fluid flow in the control valve. Hereinafter, the difference from the first embodiment will be mainly described.
FIG. 9A is a central sectional view of the seal ring 448 used in the second embodiment. FIG. 9B is a partially enlarged sectional view showing the periphery of the seal ring 448. As shown in FIG. 9A, the seal ring 448 is provided with an annular bead 449 on the upper end surface 441 thereof.

In the present embodiment, the fluid flows from the lower side to the upper side in FIG. In the closed state, the seal ring 448 receives pressure upward from the fluid. This pressure causes the bead 449 to closely contact the upper side surface 426 in the circumferential direction without any gap. Even if the high-pressure fluid wraps around between the fitting portion 422 and the seal ring 448, the bead 449 blocks the flow. Therefore, fluid leakage when the valve is closed can be suppressed.
Also in this embodiment, a bead 449 is provided on an end surface (upper end surface 441 in the present embodiment) on the low pressure side of the upper end surface 441 and the lower end surface 443 of the seal ring 448. This point is common to the first embodiment. With such a configuration, even if there is a parting line in the fitting portion, the bead can be firmly pressed using the differential pressure between the upstream pressure and the downstream pressure, and the sealing performance is ensured. be able to.

  As in the case of the first embodiment, instead of providing an annular bead on the seal ring 448, the upper end surface of the seal ring 448 may be tapered. Further, two annular beads having different diameters may be provided on the upper end surface of the seal ring 448. You may provide an annular bead in both the upper end surface and lower end surface of a seal ring. In either case, the low-rigidity portion of the seal ring is in close contact with the fitting portion 422 regardless of the position of the parting line, and fluid leakage in the closed state can be suppressed.

[Third Embodiment]
The third embodiment differs from the first embodiment in the structure of the seal ring.
FIG. 10A is a central longitudinal sectional view of a seal ring 450 according to the third embodiment. H1 in the drawing indicates the height of the main body of the seal ring 450 (distance between the upper flat surface and the lower flat surface: hereinafter also referred to as “main body height”). H2 indicates the height of the portion where the low-rigidity portion is located before the seal ring 450 is fitted to the fitting portion (hereinafter also referred to as “total height”). FIG. 10B is a partially enlarged sectional view showing the periphery of the seal ring 450. W in the drawing indicates a distance between the upper side surface 426 and the lower side surface 428 of the fitting portion 422 (hereinafter also referred to as “fitting portion width”).
In the first and second embodiments, considering that the seal ring is compressed in the axial direction due to the differential pressure between the upstream pressure and the downstream pressure, a bead is provided on the end surface on the low pressure side. The low-rigidity bead is pressed against the opposing surface of the fitting portion using the differential pressure. However, with such a configuration, a gap between the end surface on the high pressure side of the seal ring and the opposing surface of the fitting portion is increased, and the entry of the high pressure fluid is also promoted.
On the other hand, it can be said that it is preferable to originally set the height to such an extent that the seal ring has a crushing margin with respect to the fitting portion width, since the sealing ring uses the crushing margin to exhibit sealing performance. However, such a height setting makes it difficult to assemble the seal ring to the fitting portion.
Therefore, in this embodiment, the sealing performance is improved by securing the crushing allowance for the overall height of the seal ring and making the height of the main body having high rigidity smaller than the fitting portion width. That is, the seal ring 450 includes annular beads 451 and 452 on the upper end surface 441 and the lower end surface 443, respectively. In the present embodiment, the height of the portion where the beads 451 and 452 are located is the overall height H2. The main body height H1 is smaller than the fitting portion width W, and the overall height H2 is larger than the fitting portion width W.

  With such a configuration, the low-rigid beads 451 and 452 in the seal ring 450 function as crushing allowances for the fitting portion 422. Since the beads 451 and 452 are in close contact with both the upper side surface 426 and the lower side surface 428 of the fitting portion 422, leakage of fluid when the valve is closed can be suppressed.

  In addition, in a modification, it is good also as an aspect which ensures a crushing margin, providing low rigidity parts, such as a bead, in one of the upper end surface and lower end surface of a seal ring. That is, any seal ring may be used as long as it has a low-rigidity portion in an annular shape and can be brought into close contact with the fitting portion 422 in a line contact manner, and increases in the order of main body height H1 <fitting portion width W <overall height H2. Further, as in the case of the first embodiment, the seal ring may be provided with a tapered portion whose transverse section is narrowed toward the lower end surface, and the tip end portion of the tapered portion may be an annular low-rigidity portion. With such a seal ring, regardless of the presence or absence of the parting line 424, the fitting portion 422 and the seal ring can be brought into close contact with each other in the axial direction of the valve body 400, and fluid leakage in the closed state can be achieved. Can be prevented.

[Fourth Embodiment]
The fourth embodiment is different from the first embodiment in the structure of the seal ring.
FIG. 11A is a central longitudinal sectional view of a seal ring 454 according to the fourth embodiment. FIG. 11B is a partially enlarged cross-sectional view showing the periphery of the seal ring 454.

  In the present embodiment, an annular bead 455 is provided on the inner peripheral surface 457 of the seal ring 454. The seal ring 454 is fixed to the fitting portion 422 by its tight binding force. This binding force acts in the centripetal direction of the seal ring 454 and presses the bead 455 against the parting line 424. As a result, the bead 455 is firmly attached to the bottom surface 430 of the fitting portion 422 even at the position of the parting line 424, and fluid leakage is suppressed.

[Fifth Embodiment]
The fifth embodiment is different from the first embodiment in the structure of the seal ring.
FIG. 12A is a central longitudinal sectional view of a seal ring 458 according to the fifth embodiment. FIG. 12B is a partially enlarged cross-sectional view showing the periphery of the seal ring 458. An annular bead 459 is provided on the lower end surface of the seal ring 458. The seal ring 458 has a substantially rectangular cross section, and has a corner 462 at the lower part of the outer peripheral edge. The corner portion 462 has an R shape with a relatively small radius of curvature. In the present embodiment, the radius of curvature of the corner 462 is smaller than the radius of curvature of the corner 463 on the inner peripheral edge side. In the modified example, the corner may be an edge, or a C chamfer or other chamfer.

  In this embodiment, the bead 459 is in close contact with the fitting portion 422 due to the differential pressure between the upstream pressure and the downstream pressure of the fluid with respect to the seal ring 458. The seal ring 458 of the present embodiment is provided with a corner 462 instead of a taper so that the contact point with the valve seat 232 is in the vicinity of the lower end surface of the outer peripheral edge. Thereby, the seal ring 458 of the present embodiment can ensure the adhesion force due to the differential pressure to the extent that the adhesion between the bead 459 and the fitting portion 422 is sufficient. In the present embodiment, an example of the seating point of the corner portion 462 with respect to the valve seat 232 is shown. However, as the seating point is positioned on the radially outer side of the valve seat 232, the adhesion force due to the differential pressure can be increased.

In this embodiment, the corner portion 462 of the seal ring 458 abuts with the valve seat 232 in a line contact manner in an annular shape. Therefore, the seal ring 458 can be in close contact with the valve seat with higher sealing performance than when the seal ring and the valve seat abut in a surface contact manner.
Moreover, although the example which made a valve seat a taper surface was shown in this embodiment, it is good also as a surface perpendicular | vertical with respect to the axis line of a valve hole. In that case, a bead (protrusion) projecting toward the valve seat may be provided on the outer peripheral edge of the seal ring or in the vicinity thereof, and may be annularly contacted with the valve seat in a line contact manner. As the seating point of the bead is positioned on the radially outer side of the valve seat, the adhesion force due to the differential pressure can be increased.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments, and various modifications can be made within the scope of the technical idea of the present invention. Nor.

  In the embodiment, the configuration in which the seal ring effectively functions with respect to the valve body having the parting line 424 is exemplified. In the modified example, the seal ring may be applied not only to the parting line but also to traces (processing traces) remaining when the valve body is molded. The processing mark may be, for example, a protruding portion caused by scratches or burrs. The low-rigidity portion of the seal ring is in close contact with the machining mark of the fitting portion 422, and fluid leakage when the valve is closed can be suppressed.

  In the embodiment, a seal ring having a substantially square cross section is illustrated. The shape of the seal ring is not limited to this, and may be a circular cross section such as an O ring. A low-rigidity portion such as a bead (projection) may be provided along the side surface of the seal ring having a circular cross section. What is necessary is just a seal ring which has the low-rigidity part closely_contact | adhered to either surface of the fitting part 422 in the circumferential direction.

  In the embodiment, the mode in which the bead and the fitting portion 422 are in line contact is illustrated. However, the embodiment is not limited to the bead, and any mode can be used as long as the low-rigidity portion can be in close contact with the fitting portion 422 in the circumferential direction. You may make it include the cyclic | annular low-rigidity part by which the cross section was narrowed toward at least one end surface among the upper end surface and lower end surface of a seal ring. It is good also as a shape where a cross section narrows toward the end surface used as a low voltage | pressure side from the end surface used as a high voltage | pressure side among an upper end surface and a lower end surface. For example, a taper may be provided from the upper end surface to the lower end surface of the seal ring so that the longitudinal cross-sectional shape becomes a trapezoidal shape or a step shape.

  In the embodiment, the seal ring that contacts and separates from the valve seat of the control valve has been described. However, the seal ring may be applied to other places that require a sealing function. For example, you may apply to the location used for sliding parts, such as the seal ring 460. FIG.

DESCRIPTION OF SYMBOLS 100 Control valve, 120 Acting rod, 121 Step part, 122 Stopper, 123 Sliding bearing, 124 Stopper, 140 Spring, 160 Housing, 200 Body, 220 1st body, 221 Main body, 222 Introducing pipe part, 224 Introducing port, 226 Deriving Pipe part, 228 outlet port, 230 valve hole, 232 valve seat, 240 second body, 241 O-ring, 242 guide hole, 244 female thread part, 245 O-ring, 300 drive unit, 320 motor, 340 worm gear, 342 worm, 344 Worm wheel, 346 Upper stopper, 348 Male thread part, 400 Valve body, 420 Main body, 421 Leg part, 422 Fitting part, 423 Fitting part, 424 Parting line, 425 Parting line width, 426 Upper side, 428 Lower Side surface, 430 Bottom surface, 440 Seal ring, 441 Upper end surface, 442 Bead, 443 Lower end surface, 444 Seal ring, 445 Tapered part, 446 Seal ring, 447 Bead, 448 Seal ring, 449 Bead, 450 Seal ring, 451 Bead, 454 Seal ring, 455 bead, 456 taper surface, 457 inner peripheral surface, 458 seal ring, 458 bead, 460 seal ring, 462 corner, 463 corner.

Claims (5)

A body having an introduction port for introducing fluid from the upstream side, a derivation port for deriving fluid to the downstream side, and a valve seat provided in a passage connecting the introduction port and the derivation port;
A valve body that opens and closes the valve portion by attaching to and detaching from the valve seat;
An actuator that opens and closes the valve portion by driving the valve body in an axial direction,
The valve body is
A main body having a concave fitting portion provided along the outer periphery;
A seal ring fitted to the fitting portion and attached to and detached from the valve seat,
The fitting portion is
Having a first side surface and a second side surface facing in the axial direction of the valve body;
The seal ring is
A first end surface facing the first side surface and a second end surface facing the second side surface;
A control valve having an annular abutting portion that abuts against the opposite side surface in a line contact manner on at least one of the first end surface and the second end surface on the low pressure side.   The control valve according to claim 1, wherein the annular contact portion is a protrusion provided on the end face. A trace of molding remains on the body,
The control valve according to claim 1, wherein the annular abutting portion abuts on the side surface so as to intersect with the trace appearing on the side surface. A body having an introduction port for introducing fluid from the upstream side, a derivation port for deriving fluid to the downstream side, and a valve seat provided in a passage connecting the introduction port and the derivation port;
A valve body that opens and closes the valve portion by attaching to and detaching from the valve seat;
An actuator that opens and closes the valve portion by driving the valve body in an axial direction,
The valve body is
A main body having a concave fitting portion provided along the outer periphery;
A seal ring fitted to the fitting portion and attached to and detached from the valve seat,
The seal ring is
A control valve having an annular contact portion that contacts the fitting portion in a line contact manner on a surface facing the fitting portion. A body having an introduction port for introducing fluid from the upstream side, a derivation port for deriving fluid to the downstream side, and a valve seat provided in a passage connecting the introduction port and the derivation port;
A valve body that opens and closes the valve portion by attaching to and detaching from the valve seat;
An actuator that opens and closes the valve portion by driving the valve body in an axial direction,
The valve body is
A main body having a concave fitting portion provided along the outer periphery;
A seal ring fitted to the fitting portion and attached to and detached from the valve seat,
The fitting portion is
Having a first side surface and a second side surface facing in the axial direction of the valve body;
The seal ring is
A first end face facing the first side face and a second end face facing the second side face;
An annular low-rigidity portion whose transverse section is narrowed toward at least one of the first end surface and the second end surface;
The height of the portion where the low-rigidity portion is located is set to be larger than the distance between the first side surface and the second side surface before fitting to the fitting portion. And control valve.

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