JP6449208B2 - Pressure reducing valve - Google Patents

Description

  The present invention relates to a pressure reducing valve used in a hot water supply facility or the like.

  As this kind of pressure-reducing valve, as described in Patent Document 1 below, for example, a valve having a resin valve body, a valve rod, and a pressure-sensitive reaction member (diaphragm device) is known.

  Specifically, in the pressure reducing valve described in Patent Document 1, a valve chamber having a valve seat with a valve port is provided therein, an outflow chamber is provided below the valve port, and the valve chamber is provided at an outer peripheral portion. A valve main body comprising a single member provided with a primary side inlet connected to the outlet and a secondary side outlet connected to the outflow chamber, and a valve body part for opening and closing the valve port from below, the valve A valve stem that is slidably inserted in the main body in the vertical direction, and a feeling that is attached to the valve main body to drive the valve rod in the vertical direction by sensing the secondary pressure at the secondary outlet. A pressure response member.

JP2015-210535A

  By the way, in such a conventional pressure reducing valve, a substantially short cylindrical rubber seal member that contacts and separates from the valve chamber is externally fixed to the lower end portion of the valve shaft that is inserted into the valve port. The upper surface (specifically, a portion exposed from a substantially conical locking portion formed integrally with the valve shaft so as to sandwich the seal member) has a substantially flat shape. Therefore, when the fluid passes between the valve shaft and the valve port and passes through the valve port, the flow path suddenly narrows, and the fluid collides with the upper surface of the seal member and flows in a substantially perpendicular direction. Therefore, there is a possibility that fluid separation occurs on the upper surface of the upper surface and negative pressure is generated on the valve port side to cause cavitation. As a result, the balance of the pressure applied to the valve body portion changes abruptly, and there is a concern that a force in the valve closing direction acts on the valve body portion.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a pressure reducing valve that can prevent the occurrence of cavitation associated with fluid separation and can effectively suppress a change in pressure balance applied to a valve body portion. And

In order to achieve the above object, a pressure reducing valve according to the present invention includes a valve chamber having a valve seat with a valve port therein, an outflow chamber provided below the valve port, and the valve on an outer peripheral portion. A valve body provided with a primary side inlet connected to a chamber and a secondary side outlet connected to the outlet chamber, a valve body for opening and closing the valve port from below, and a valve body And a pressure sensitive sensor attached to the valve body to drive the valve stem in the vertical direction by detecting the secondary pressure at the secondary outlet. A pressure-reducing valve comprising: a responsive member, and continuously extending from a horizontal direction toward a lower side as it goes from the inside to the outside on at least a part of a facing surface of the valve body portion facing and separating from the valve seat. inclined surface portion that inclines are provided on the valve body portion, a valve to be inserted into the valve port And the upper surface of the valve body part is brought into contact with the lower surface of the upper pressing part projecting from the outer periphery of the valve shaft, and the opposing surface is placed on the outer peripheral part from the upper pressing part in the valve body part. And a pressure receiving recess that is recessed downward is provided at the outer end of the outer peripheral portion of the valve body portion .

  In a preferred embodiment, the entire facing surface is the inclined surface portion.

  In a preferred embodiment, the inclination angle of the inclined surface portion with respect to the horizontal direction is constant or continuously reduced from the inside toward the outside.

  In another preferred embodiment, the outer peripheral surface of the upper pressing portion and the opposed surface of the valve body portion are continuously connected.

  In a further preferred form, the valve body portion is constituted by a seal member that contacts and separates from the valve seat, and a lower pressing member that presses the lower side and the outer periphery of the seal member, and the pressure receiving recess includes the seal It is formed in the space between the outer peripheral part of a member and the inner wall of the upper end part of the outer cylinder part distribute | arranged to the outer periphery of the said sealing member in the said lower side pressing member.

  According to the pressure reducing valve according to the present invention, at least a part of the facing surface facing and separating from the valve seat in the valve body portion, the slope continuously tilting downward from the horizontal direction as it goes from the inside to the outside. Since the surface portion is provided, for example, compared with the conventional one in which the upper surface of the valve body portion is substantially flat, the fluid can flow smoothly along the inclined surface portion to the secondary outlet side. It becomes possible and generation | occurrence | production of fluid peeling can be suppressed. Therefore, it is possible to prevent the occurrence of cavitation due to fluid separation, and to suppress a change in pressure balance applied to the valve body portion.

  Further, the upper surface of the valve body portion is brought into contact with the lower surface of the upper pressing portion projecting from the outer periphery of the valve shaft, and the outer peripheral surface of the upper pressing portion and the opposing surface of the valve body portion are continuously connected. Therefore, the flow of the fluid becomes smoother, the effect of preventing the occurrence of cavitation due to fluid separation can be enhanced, and the change in the pressure balance applied to the valve body can be more effectively suppressed.

  Furthermore, since the pressure receiving recess is provided at the outer end of the outer peripheral portion from the upper pressing portion in the valve body portion, it is possible to suppress a change in flow rate characteristics by allowing the valve body portion to receive dynamic pressure through the pressure receiving recess. Can do.

Sectional drawing which shows the pressure-reduction valve which concerns on 1st Embodiment. The expanded sectional view which shows the part of the valve body part at the time of valve opening. The expanded sectional view which shows the part of the valve body part at the time of valve closing. It is a disassembled perspective view which shows the part of a relief valve. The partial expanded sectional view for demonstrating the flow of the fluid regarding the pressure-reduction valve of 1st Embodiment. The fragmentary sectional view which shows the valve body part of the pressure-reduction valve which concerns on 2nd Embodiment.

  Hereinafter, an embodiment of a pressure reducing valve according to the present invention will be described with reference to the drawings. In the following description, descriptions representing positions and directions such as up and down, left and right, and front and rear are given for the sake of convenience in accordance with the drawings in order to avoid complicated description, and the positions and directions in the actual use state. It does not point to.

<First Embodiment>
FIG. 1 is a sectional view showing a pressure reducing valve according to the first embodiment. The pressure reducing valve 1 according to the present embodiment is used in, for example, hot water supply equipment, and mainly includes a valve body 10, a valve rod 30 housed in the valve body 10, and a diaphragm as a pressure sensitive response member. Device 40.

  The valve body 10 is formed of, for example, a resin material, and a cylindrical valve chamber 21 having a valve seat 23 with a valve port 22 is provided therein, and an outflow chamber 26 is provided below the valve port 22. Is provided. The valve body 10 has an upper surface opening 10a that opens so as to be continuous with the valve chamber 21, and a lower surface opening 10b that opens so as to be continuous with the outflow chamber 26. The lower surface opening 10b has a thick, substantially disk-shaped bottom lid. It is blocked by the member 60. The upper surface opening 10 a is closed by the diaphragm device 40.

  A primary side inlet 11 connected to the valve chamber 21 and a secondary side outlet 12 connected to the outlet chamber 26 are respectively formed laterally on the outer periphery of the valve body 10. The valve chamber 21, the primary side inlet 11, the outflow chamber 26, and the secondary side outlet 12 are juxtaposed in the horizontal direction (that is, the horizontal direction), and their central axes are in the vertical direction (that is, the vertical direction). Are arranged at a predetermined distance. In other words, the primary side inlet 11 and the secondary side outlet 12 are not coaxially arranged in the vertical direction. For this reason, a step portion 13 is formed between the valve chamber 21 and the secondary outlet 12 which constitutes a part of the valve seat 23 with the valve port 22 described above. In addition, the primary side inlet port 11 and the secondary side outlet port 12 are arrange | positioned coaxially in the vertical direction, and the level | step-difference part 13 can be formed by changing the internal shape of the valve main body 10. FIG.

  A guide hole 19 extending in the vertical direction is formed between the upper surface opening 10 a of the valve body 10 and the valve chamber 21 so as to hold the valve rod 30. The valve rod 30 is slidably fitted into the guide hole 19 along the vertical direction in order to open and close the valve port 22 from the lower side (that is, the outflow chamber 26 side). This valve stem 30 is mainly provided in a valve shaft 38 that is slidably inserted into the guide hole 19 of the valve body 10 and is inserted into the valve port 22, and a valve port provided at the lower end of the valve shaft 38. And a valve body portion 35 for opening and closing 22 from the lower side.

  The valve shaft 38 extends from the upper side to the outflow chamber 26 through the diaphragm support portion 32 for supporting the diaphragm device 40, the sliding large diameter portion 33 slidably inserted into the guide hole 19, and the valve port 22. While having the insertion small diameter part 34, the cone-shaped upper side press part 36 which presses down the sealing member 37 (after-mentioned) of the valve body part 35 from upper direction protrudes from the substantially outer periphery of the insertion small diameter part 34. As shown in FIG. A through hole 31 extending in the vertical direction is formed in the center of the valve shaft 38. Female threaded portions 31 a and 31 b are respectively screwed on the peripheral walls of the upper end portion and the lower end portion of the through hole 31. An O-ring 28 is attached to an annular groove provided on the outer periphery of the sliding large-diameter portion 33 so as to seal a clearance between sliding surfaces formed between the guide hole 19 and the annular groove.

  The valve body portion 35 has a substantially truncated cone shape and is externally mounted on the lower end portion of the valve shaft 38. Specifically, the valve body portion 35 is attached to the outer periphery of the lower end portion of the insertion small-diameter portion 34, has a substantially truncated cone shape that is externally mounted on the lower end portion of the insertion small-diameter portion 34, and has a slightly larger diameter than the valve port 22. And a bottomed cylindrical lower pressing member 39 that is fixed to the bottom of the insertion small-diameter portion 34 and presses the seal member 37 from the lower side and the outer periphery. The seal member 37 is fixed to the valve shaft 38 by a fastening screw 27 that is screwed into a female screw portion 31 b provided at the lower end portion of the through hole 31 so as to be sandwiched between the upper pressing portion 36 and the lower pressing member 39. Has been.

  FIG. 2 is an enlarged cross-sectional view showing a portion of the valve body portion when the valve is opened, and FIG. 3 is an enlarged cross-sectional view showing a portion of the valve body portion when the valve is closed. The substantially frustoconical seal member 37 is formed of, for example, rubber suitable for sealing the valve port 22, and can be brought into contact with and separated from the valve seat 23 as the valve rod 30 moves up and down. An upper surface 37b that contacts the lower surface 36b, and an opposing surface 37a that is a truncated cone surface (that is, a tapered surface) that faces and separates from the valve seat 23.

  The upper surface 37 b of the seal member 37 is formed in a flat shape and is brought into contact with the lower surface 36 b of the upper pressing portion 36. On the other hand, the opposing surface 37a of the seal member 37 is formed at the outer peripheral portion (that is, the outer peripheral portion from the upper presser portion 36 in the valve body portion 35) than the upper presser portion 36 in the seal member 37, and the whole is outside from the inner side. It is set as the inclined surface part which inclines toward the downward direction from a horizontal direction as it goes to. In the following description, the facing surface 37a is referred to as an inclined surface portion 37a. In the present embodiment, the inclination angle θ with respect to the horizontal direction of the inclined surface portion 37a is constant, and the inclination angle θ is 32.5 °.

  Here, the upper surface 37b of the seal member 37 is “the upper surface of the valve body part” described in the claims, and the inclined surface part 37a of the seal member 37 is “opposite the valve seat in the valve body part”. And the “facing surfaces separated from each other”.

  Further, in the present embodiment, like the inclined surface portion 37a of the seal member 37, the outer peripheral surface 36a of the upper pressing portion 36 is inclined downward from the horizontal direction as it goes from the inside to the outside. The outer peripheral surface 36a and the inclined surface portion 37a are continuously connected without a step. Here, the continuous connection means that the angle of inclination (in other words, the tangential direction) is the same at the connecting portion between the outer peripheral surface 36a of the upper pressing portion 36 and the inclined surface portion 37a of the seal member 37. means.

  On the other hand, the lower pressing member 39 is formed of, for example, a metal material, and extends from the peripheral surface of the flat plate portion 39a and has a circular flat plate portion 39a extending along the bottom surface 37c of the seal member 37. It is comprised from the distributed outer cylinder part 39b.

  A pressure receiving recess S is provided at the outer end of the inclined surface portion 37 a of the seal member 37. Specifically, the upper end portion 39c of the outer cylindrical portion 39b of the lower pressing member 39 protrudes upward from the outer end of the inclined surface portion 37a of the seal member 37, and the inner wall of the protruding portion and the outer periphery of the inclined surface portion 37a. A pressure receiving recess S having a triangular cross section for receiving dynamic pressure is defined.

  Further, as shown in FIG. 1, the diaphragm device 40 senses the secondary pressure of the secondary outlet 12 and closes the upper surface opening 10a of the valve body 10 so as to drive the valve rod 30 in the vertical direction. It is attached to the top.

  Specifically, the diaphragm device 40 cooperates with a diaphragm 41 disposed so as to cover the upper surface opening 10 a of the valve body 10, and a diaphragm receiving portion 10 c provided on the outer periphery of the diaphragm 41 at the upper end of the valve body 10. A bell-shaped cap 42 having a stepped cross section that is pressed and sealed at the lower end surface portion 42b, and a compression coil spring that is arranged between the diaphragm 41 and the upper portion of the cap 42 and biases the diaphragm 41 downward. 45 and an insertion hole 43a through which a fastening screw 29 screwed into the female thread portion 31a is inserted, and is placed on the inner peripheral portion of the diaphragm 41 to receive the lower end of the compression coil spring 45. The lower spring receiving member 43 having a generally inverted cross-sectional shape that holds the diaphragm 41 in cooperation with the diaphragm support portion 32 and the upper end of the compression coil spring 45 An upper spring receiving member 46 having a generally concave shape in cross section, in which a receiving seat 46a projecting outward from the upper end, and a substantially cylindrical shape in which a lower end is in contact with the upper spring receiving member 46 and a hexagonal hole is formed at the upper end. The hexagon socket head adjusting screw 47 is provided. The diaphragm device 40 is assembled to the valve body 10 by fastening and fixing the lower end surface portion 42b of the cap 42 to the diaphragm receiving portion 10c of the valve body 10 with a plurality of bolts (not shown).

  In the diaphragm device 40, in order to adjust the set load of the compression coil spring 45, a female screw portion 42c is formed on the inner periphery of the upper mouth tube portion 42a of the cap 42, and the outer periphery of the female screw portion 42c and the hexagonal hole adjusting screw 47 is formed. And a male threaded portion 47a provided on the screw. When the adjusting screw 47 is rotated, the set load of the compression coil spring 45 that is compressed between the lower spring receiving member 43 and the upper spring receiving member 46 is adjusted. Thereby, the pressure when the diaphragm device 40 is opened is adjusted.

  A pressure sensitive chamber 24 is defined between the diaphragm 41 and the upper surface of the diaphragm support portion 32 of the valve shaft 38. In addition, although not shown in the drawing, a pressure-sensitive pressure comprising a vertical hole connected to the pressure-sensitive chamber 24 at the peripheral side of the valve body 10 on the secondary outlet 12 side so as to avoid interference with a later-described relief valve 50. A passage is formed. The secondary side pressure of the secondary side outlet 12 is detected by the diaphragm device 40 as a pressure sensitive response member via the pressure sensitive passage and the pressure sensitive chamber 24, so that it is connected to the diaphragm 41 of the diaphragm device 40. The valve stem 30 is driven in the vertical direction within the valve body 10.

  The bottom cover member 60 that closes the lower surface opening 10b of the valve body 10 from below has a disk-like base 61, and is a fastening screw fastened to the lower end of the valve shaft 38 of the valve stem 30 on the upper surface of the base 61. In order to avoid interference with 27, a bowl-shaped recess 63 is provided, and a substantially annular stopper 62 is erected from the upper surface of the base 61 so as to surround the recess 63. Further, an O-ring 64 as a sealing material is attached to the annular groove provided on the outer periphery of the base 61.

  The base 61 of the bottom cover member 60 is fastened and fixed to the valve body 10 by a plurality of bolts 65. The stopper portion 62 provided on the base portion 61 is a structure for restricting the downward movement of the valve stem 30, and when the valve stem 30 is lowered when the valve port 22 is opened, the lower side of the valve body portion 35 is provided. The pressing member 39 comes into contact with the stopper portion 62, and the valve stem 30 cannot be lowered any further. Further, in order to prevent sticking to the lower pressing member 39 of the valve rod 30 at the time of contact, the stopper portion 62 has a plurality of notches (in the illustrated example, with respect to the paper surface). Cutouts are provided at four positions on the front, rear, left and right.

  Further, in the pressure reducing valve 1 of the present embodiment, in order to protect the resin valve body 10 and other components from abnormally high pressure, the primary pressure is a predetermined value (the pressure resistance of the valve body 10 and other components). A relief valve 50 that opens when the limit value is exceeded is provided in the step portion 13.

  FIG. 4 is an exploded perspective view showing a relief valve portion. 2, 3, and 4, the relief valve 50 communicates with the relief valve port 51 including an orifice that opens to the valve chamber 21, and communicates with the relief valve port 51 and opens to the secondary outlet 12. And a storage hole 57 formed of a stepped cylindrical space. The storage hole 57 further includes a first storage hole 52 formed of a cylindrical space that communicates with the relief valve port 51, and a second storage hole that opens to the secondary side outlet 12 and has a larger diameter than the first storage hole 52. 53a. And the relief valve port 51, the 1st accommodation hole 52, and the 2nd accommodation hole 53a are each formed laterally, and are arrange | positioned coaxially so that it may have a level | step difference toward the right side from the left side.

  Specifically, the first storage hole 52 has an inner diameter larger than that of the relief valve port 51, and a rubber ball valve body 55 that opens and closes the relief valve port 51 inside the first storage hole 52, and closes the ball valve body 55. A valve closing spring 56 made of a compression coil spring that is biased in the direction is housed. The second storage hole 53 a having a diameter larger than that of the first storage hole 52 is a through-hole of the cylindrical member 53 fixed to the secondary-side outlet 12 side (the mounting hole 58 provided in the first storage hole 52). One end of which communicates with the first storage hole 52 and the other end opens to the secondary outlet 12.

  More specifically, the stepped portion 13 of the valve body 10 is provided with a mounting hole 58 that communicates with the first storage hole 52 and has a larger diameter than either the first storage hole 52 or the second storage hole 53a. An annular groove 58a that opens to the secondary outlet 12 side is formed on the outer periphery of the relief hole 51 side in the mounting hole 58. A part of the cylindrical member 53 is inserted into the mounting hole 58 in the mounting hole 58, and the remaining part is exposed to the outside of the mounting hole 58 (secondary outlet 12 side). It is fixed.

  A through hole that forms the second storage hole 53 a is formed in the center of the cylindrical member 53. The second storage hole 53 a has a circular cross section and has a size that allows the ball valve body 55 and the valve closing spring 56 to be inserted therethrough. A pair of projecting portions 53b projecting from the inner wall surface are provided on the inner wall surface of the second storage hole 53a at the end on the secondary outlet 12 side. The pair of protrusions 53b are arranged at an interval of 180 ° along the circumferential direction of the second storage hole 53a.

  On the other hand, an annular weld 53c having an inner diameter larger than the inner diameter of the second storage hole 53a is provided at the end of the cylindrical member 53 opposite to the end where the projection 53b is formed. The welded portion 53c is fitted into the annular groove 58a of the mounting hole 58, and the resin material is instantaneously melted by ultrasonic welding and joined to the stepped portion 13 provided with the mounting hole 58. Thus, the cylindrical member 53 is integrated with the valve body 10.

  A spring receiving lid 54 that holds the valve closing spring 56 in a compressed state is engaged and fixed inside the second storage hole 53 a in the storage hole 57. The spring receiving lid 54 is disposed in the storage hole 57 so as to be movable along the direction of the axis O and rotatable about the axis O. Specifically, the spring receiving lid 54 includes a left small diameter portion 66 having a slightly smaller diameter than the first storage hole 52 and a right large diameter portion 59 having a slightly larger diameter than the first storage hole 52.

  The left small diameter portion 66 has a cylindrical shape, and is inserted into the first storage hole 52 when the spring receiving lid 54 is inserted into the storage hole 57, and comes into contact with the distal end portion of the valve closing spring 56 to thereby close the valve closing. The spring 56 is pressed against the ball valve body 55 to compress it.

  The right large-diameter portion 59 is formed integrally with the left small-diameter portion 66, and its outer diameter is substantially the same as or slightly smaller than the inner diameter of the second storage hole 53a so as to be inscribed in the second storage hole 53a. It is getting smaller. The right large diameter portion 59 is engageable with the protrusion 53b and a clearance groove 59a for avoiding interference with the protrusion 53b on the outer periphery according to the shape of the protrusion 53b of the cylindrical member 53. A plurality of engagement recesses 59b are provided (two in this embodiment). In the present embodiment, the escape grooves 59a and the engagement recesses 59b are alternately arranged at 90 ° intervals along the circumferential direction of the second storage hole 53a.

  Further, when the spring receiving lid 54 is inserted into the storage hole 57, an engagement recess 59b is formed on the outer periphery of the right large diameter portion 59 so that air inside the second storage hole 53a and the first storage hole 52 is released. An air escape groove 59d is provided so as to communicate with each other. By doing so, even when the cylindrical member 53 and the spring receiving cover 54 are in close contact with each other, the operation of inserting the spring receiving cover 54 into the storage hole 57 can be performed more smoothly.

  Further, the large-diameter portion 59 on the right side of the spring receiving lid 54 abuts against the protrusion 53 b of the cylindrical member 53 as the circumferential rotation in the accommodation hole 57 and restricts the rotation of the spring receiving lid 54. A rotation restricting portion 59e is provided. The rotation restricting portion 59e is located between the adjacent escape groove 59a and the engagement recess 59b, and protrudes from the front end surface 59c to the secondary side outlet 12 side.

  A through hole 54 a is provided in the center of the spring receiving lid 54 along the direction of insertion into the cylindrical member 53 (that is, the direction of the axis O). The through hole 54a is provided for releasing the air inside the first storage hole 52 and the primary pressure when the valve is opened to the secondary outlet 12 side.

  As shown in FIGS. 2 and 3, the through hole 54 a has a stepped structure, a portion near the first storage hole 52 is a small-diameter cross-sectional circular portion, and a portion near the secondary outlet 12 side. Is a non-circular portion having a large cross section. The large-diameter non-circular cross section is a tool insertion hole 59f. The tool insertion hole 59f is a structure for rotating the spring receiving cover 54, and the length of the through hole 54a from the end surface on the secondary outlet 12 side of the spring receiving cover 54 (that is, the front end surface 59c of the through hole 54a). It extends to about half the length. In the present embodiment, the tool insertion hole 59f has a hexagonal cross section, but may have a noncircular shape such as a polygonal shape or an elliptical shape other than the hexagonal shape.

  By providing the tool insertion hole 59f in this way, the spring receiving cover 54 can be easily rotated with, for example, a hexagon wrench after the spring receiving cover 54 is inserted into the storage hole 57.

  In the relief valve 50 having the above structure, when the primary pressure exceeds a predetermined value, the force in the valve opening direction acting on the ball valve body 55 overcomes the urging force in the valve closing direction of the valve closing spring 56, and the relief valve 50 opens. Therefore, the primary side inlet 11 and the secondary side outlet 12 communicate with each other. Accordingly, the primary pressure flows to the secondary outlet 12 side through the valve chamber 21 → the relief valve port 51 → the first storage hole 52 → the through hole 54 a of the spring receiving lid 54. Thereby, the primary pressure is reduced.

  In the pressure reducing valve 1 of the present embodiment, the entire facing surface facing and separating from the valve seat 23 of the seal member 37 is an inclined surface portion 37a that is inclined downward from the horizontal direction as it goes from the inside to the outside. At the same time, the outer peripheral surface 36a of the upper pressing portion 36 is similarly inclined, and is continuously connected to the inclined surface portion 37a with virtually no step. Therefore, as shown in FIG. 5, the fluid can smoothly flow to the secondary outlet side along the inclination of the outer peripheral surface 36 a of the upper pressing portion 36 and the inclined surface portion 37 a of the seal member 37. Become. As a result, the occurrence of fluid separation can be suppressed, the occurrence of cavitation accompanying fluid separation can be prevented, and the change in the pressure balance applied to the valve body portion 35 can be suppressed.

  In addition, a pressure receiving recess formed between the upper end portion 36c of the lower pressing member 39 and the inner wall of the upper end portion 39c of the lower pressing member 39 at the outer end of the outer pressing portion 36 (ie, the inclined surface portion 37a) from the upper pressing portion 36 of the seal member 37. Since S is provided, dynamic pressure can be stably received by the valve body 35 in the pressure receiving recess S (see arrow F). Thereby, a change in the flow rate characteristic can be suppressed.

Second Embodiment
FIG. 6 is a partial cross-sectional view showing a valve body portion of a pressure reducing valve according to the second embodiment. The difference between the pressure reducing valve 2 of the present embodiment and the first embodiment is a curved surface in which the inclined surface portion 37d of the seal member 37 and the outer peripheral surface 36c of the upper pressing portion 36 are respectively convex downward in a sectional view. Since the other structure is the same as that of the first embodiment, repeated description of the same structure is omitted.

  As shown in FIG. 6, the outer peripheral surface 36c of the upper pressing portion 36 and the inclined surface portion 37d of the seal member 37 are formed such that the inclination angle θ continuously decreases from the inside toward the outside. The inclined surface portion 37d of the seal member 37 is continuously connected to the outer peripheral surface 36c of the upper pressing portion 36 without a step.

  Since the pressure reducing valve 2 configured in this way has a smoother fluid flow than the first embodiment, the pressure applied to the valve body 35 and the effect of preventing the occurrence of cavitation due to fluid separation. The effect of suppressing changes in balance can be further enhanced.

  In this case, the dynamic pressure received by the valve body 35 (especially the seal member 37) is larger than that of the first embodiment, so that the upper end portion 39c of the outer cylinder portion 39b of the lower pressing member 39 does not protrude. (That is, the pressure receiving recess S may be omitted).

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the present invention described in the claims. It can be changed.

  For example, in the first and second embodiments described above, the outer peripheral surfaces 36a and 36c of the upper pressing portion 36 and the inclined surface portions 37a and 37d of the seal member 37 are both tapered surfaces or curved surfaces that protrude downward. One of the outer peripheral surface of the upper pressing portion 36 and the inclined surface portion of the seal member 37 may be a tapered surface and the other may be a curved surface that protrudes downward. The entire upper surface of the seal member 37 may be an inclined surface portion without providing the upper pressing portion 36.

  Further, the pressure receiving recess S is not necessarily formed on the inner wall of the upper end portion 39c of the outer cylinder portion 39b of the lower pressing member 39. For example, the pressure receiving recess S is formed on the outer peripheral portion of the inclined surface portion 37a of the seal member 37, for example, with the seal member 37 You may provide the pressure receiving recessed part which consists of an integrated recessed part.

1, 2 Pressure reducing valve 10 Valve body 11 Primary side inlet 12 Secondary side outlet 13 Stepped portion 21 Valve chamber 22 Valve port 23 Valve seat 26 Outflow chamber 30 Valve rod 35 Valve body portion 36 Upper pressing portions 36a, 36c 37 Seal member 37a Inclined surface (opposite surface)
37d Inclined surface portion 38 Valve shaft 39 Lower pressing member 39a Flat plate portion 39b Outer tube portion 39c Upper end portion 40 Diaphragm device 41 Diaphragm 42 Cap 43 Lower spring receiving member 45 Compression coil spring 46 Upper spring receiving member 47 Adjustment screw 50 Relief valve 51 Relief valve port 52 First storage hole 53 Cylindrical member 53a Second storage hole 53b Protruding part 53c Welding part 54 Spring receiving cover 54a Through hole 55 Ball valve body 56 Valve closing spring 57 Storage hole 58 Mounting hole 59 Right large diameter part 59a Escape groove 59b Engagement recess 59c End face 59d Air escape groove 59e Rotation restricting part 59f Tool insertion hole 60 Bottom cover member 66 Left small diameter part S Pressure receiving recess

Claims (5)

A valve chamber having a valve seat with a valve port is provided therein, an outflow chamber is provided below the valve port, and a primary side inflow port connected to the valve chamber on an outer peripheral portion and a secondary side connected to the outflow chamber A valve body provided with an outlet, a valve body part for opening and closing the valve port from below, and a valve rod slidably inserted in the valve body in a vertical direction; A pressure-sensitive responsive member attached to the valve body to sense the secondary pressure at the secondary outlet and drive the valve stem in the vertical direction,
An inclined surface portion that is continuously inclined downward from the horizontal direction as it goes from the inside to the outside is provided on at least a part of the facing surface facing and separating from the valve seat in the valve body portion ,
The valve body is externally mounted on a valve shaft inserted through the valve port,
The upper surface of the valve body part is brought into contact with the lower surface of the upper pressing part protruding from the outer periphery of the valve shaft, and the opposing surface is provided on the outer peripheral part of the upper pressing part in the valve body part,
A pressure-reducing valve, wherein a pressure- receiving recess that is recessed downward is provided at an outer end of the outer peripheral portion of the valve body portion .   The pressure reducing valve according to claim 1, wherein the entire opposing surface is the inclined surface portion.   3. The pressure reducing valve according to claim 1, wherein an inclination angle of the inclined surface portion with respect to a horizontal direction is constant or continuously decreased from an inner side toward an outer side. The pressure reducing valve according to any one of claims 1 to 3, wherein an outer peripheral surface of the upper pressing portion and the opposing surface of the valve body portion are continuously connected. The valve body portion is composed of a seal member that contacts and separates from the valve seat, and a lower pressing member that presses the lower side and outer periphery of the sealing member,
The pressure receiving recess is formed in a space between an outer peripheral portion of the seal member and an inner wall of an upper end portion of an outer cylinder portion disposed on an outer periphery of the seal member in the lower pressing member. The pressure reducing valve according to any one of claims 1 to 4 .

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