JP2018112226A - Relief valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a relief valve that can suppress variation in set pressure on a primary side until a valve element opens as much as possible.SOLUTION: A forcible valve opening mechanism 40 for forcibly opening a pressure response valve 20 has: a valve lifting shaft 41 arranged so as to be movable relative to the pressure response valve 20; and a manual operation lever 60 for pressing down the valve lifting shaft 41 by acting on the valve lifting shaft 41. A pressure adjustment member 45 for adjusting primary-side preset pressure until the pressure response valve 20 opens is screwed to a valve body 10.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a relief valve used in, for example, a hot water supply device.

  Conventionally, as a relief valve, a valve body with a primary side connection port and a secondary side connection port, and provided between the primary side connection port and the secondary side connection port, when the pressure on the primary side exceeds the set pressure A valve body for releasing the pressure on the primary side to the secondary side, and a forcible valve opening mechanism for forcibly opening the valve body in an emergency or maintenance inspection, etc. There is known one provided with a pressure adjusting mechanism for adjusting the set pressure on the primary side until the valve is opened.

  As the forced valve opening mechanism, for example, as described in Patent Documents 1 and 2 below, a manual operation lever rotatably supported by the valve body, a movement that moves in the axial direction in accordance with the operation of the manual operation lever A nut member that is a body, a valve shaft that is screwed into a nut member (screw hole thereof) and is slidably fitted into the upper portion of the valve body, and is operated by operating a manual operation lever. A lift valve shaft that is integrally connected to the nut member is pushed down.

  On the other hand, the pressure adjusting mechanism utilizes screw engagement between a valve lift shaft and a nut member constituting a forced valve opening mechanism, and the valve lift shaft is rotated relative to the nut member to move in the axial direction. The set pressure on the primary side can be adjusted by changing the clearance between the lift shaft (lower end) and the valve body (upper end).

Japanese Patent No. 5518029 JP 2013-87805 A

  However, in the conventional relief valves described in Patent Documents 1 and 2, since the manual operation lever directly acts on the nut member constituting the pressure regulating mechanism when the valve body is forcibly opened, the operation of the manual operation lever The nut member is worn by the repetition of the above, the screw shaft between the valve shaft and the nut member constituting the pressure adjusting mechanism is loosened, and the gap between the valve shaft and the valve body changes, and the primary side There was a possibility that the set pressure of would change.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a relief valve that can suppress the change in the set pressure on the primary side until the valve is opened as much as possible. There is to do.

  In order to solve the above problems, a relief valve according to the present invention is disposed between a valve body having a primary side connection port and a secondary side connection port, and between the primary side connection port and the secondary side connection port. A valve body that opens when the pressure on the primary side becomes equal to or higher than a set pressure, and releases the pressure on the primary side to the secondary side, and in order to forcibly open the valve body, A lift valve shaft that is movably disposed on the valve shaft, and a forcible valve opening mechanism that has a manual operation lever that acts on the lift valve shaft to push down the lift valve shaft. The pressure adjusting member for adjusting the set pressure on the side is screwed to the valve body and is attached.

  In a preferred aspect, the pressure adjusting member is inserted into an inner cylinder portion formed in the valve body along the opening / closing direction of the valve body and screwed.

  In another preferred embodiment, the pressure regulating member has a cylindrical shape, and the valve lift shaft is slidably inserted into the pressure regulating member.

  In a more preferred embodiment, a compression coil spring is mounted between the pressure regulating member and the lift shaft.

  In another preferred embodiment, the pressure regulating member is provided with a stopper portion that defines a movement limit of the valve shaft relative to the valve body.

  In a further preferred aspect, the stopper portion is provided at an upper end portion of the pressure adjusting member.

  In a further preferred aspect, an engagement groove for rotating the pressure regulating member relative to the valve body is provided at the upper end of the pressure regulating member.

  According to the relief valve of the present invention, the forcible valve opening mechanism for forcibly opening the valve element acts on the valve lift shaft disposed to be movable with respect to the valve element and the valve lift shaft. In addition to having a manual operation lever that pushes down the valve shaft, a pressure adjustment member that adjusts the set pressure on the primary side until the valve body opens is screwed onto the valve body. The manual operation lever does not directly act on the pressure adjusting member. Therefore, deformation due to wear or the like of the pressure adjusting member and loosening of the screwing of the pressure adjusting member with respect to the valve body are suppressed, so that changes in the set pressure on the primary side until the valve body opens can be suppressed as much as possible. it can.

The perspective view which shows one Embodiment of the relief valve which concerns on this invention. The longitudinal cross-sectional view which shows the valve closing state of the relief valve shown by FIG. The longitudinal cross-sectional view which shows the valve opening state of the relief valve shown by FIG. The longitudinal cross-sectional view which shows the operation state of the forced valve opening state of the relief valve shown by FIG. The longitudinal cross-sectional view which shows the hold state of the forced valve opening state of the relief valve shown by FIG.

  Hereinafter, embodiments of a relief valve according to the present invention will be described with reference to the drawings.

<Configuration of relief valve 1>
FIG. 1 is a perspective view showing an embodiment of a relief valve according to the present invention. 2 to 5 are longitudinal sectional views showing the relief valve shown in FIG. 1. FIG. 2 is a valve closing state, FIG. 3 is a valve opening state, FIG. 4 is an operation state in a forced valve opening state, FIG. Reference numeral 5 denotes a hold state in the forced valve opening state.

  Note that the relief valve 1 of the present embodiment is basically used in a state where the secondary side connection port 8 provided in the valve main body 10 is in the lower side and is incorporated in the hot water supply apparatus.

  The relief valve 1 of the illustrated embodiment mainly includes a valve body 10, a pressure response valve (valve element) 20 that is disposed inside the valve body 10 and opens and closes according to the pressure on the primary side, and a diaphragm valve body. 30 and a forced valve opening mechanism 40 including a valve lift shaft 41, a manual operation lever 60, and the like.

  The valve body 10 is divided into a synthetic resin lower case 10A and upper case 10B. The lower case 10A has a cylindrical shape with a large step toward the upper side, and the upper case 10B has a cylindrical shape with a large step toward the lower side. The lower case 10A and the upper case 10B are fastened and fixed to each other by, for example, a tapping screw 19.

  An accommodation hole 13 for accommodating the pressure response valve 20 is formed in a substantially inverted truncated cone shape from the upper stage part to the middle stage part of the lower case 10A. A support portion 13 a that supports the outer peripheral side (outer skirt portion 22 c) of the pressure response valve 20 in order to guide the movement of the pressure response valve 20 is provided in the accommodation hole 13 (inner peripheral surface thereof) along the circumferential direction. And projecting at a plurality of locations (three locations at equal angular intervals in the illustrated example). Between the adjacent support portions 13a, a vertical passage having a fan shape in which a fluid such as steam or hot water flows is formed, and the upper end portion of the support portion 13a is lowered by the diaphragm valve body 30 (the diaphragm 31 thereof). It is a stopper that defines the limit. A lower primary portion of the lower case 10A is provided with a cylindrical primary side connection port 7 that communicates with the accommodation hole 13 and is connected to a primary side (for example, an upper portion of a hot water storage tank) by piping or the like.

  The primary side connection port 7 has a diameter slightly smaller than the minimum diameter of the accommodation hole 13, and a (annular) stepped portion (step surface) formed between the primary side connection port 7 and the accommodation hole 13. ) 11 is a spring receiver that receives the lower end of the first valve closing spring 12 that urges the pressure response valve 20 upward (in the valve closing direction). The stepped portion 11 has a fan-shaped positioning portion 11a in a plan view in which a lower end portion of the first valve closing spring 12 is fitted inside to limit the movement of the first valve closing spring 12. A plurality of locations (in the illustrated example, three locations at equal angular intervals and below the support portion 13a) are provided along the circumference of the spring 12.

  The pressure response valve (valve element) 20 has a stepped cylindrical shape whose upper end is closed. From the upper side, a small diameter portion 21 having a relatively small diameter, and a small diameter portion 21 are integrated with the small diameter portion 21. And a large-diameter portion 22 formed relatively large. The small-diameter portion 21 is inserted into a contact member 32 (a cylindrical portion thereof) of a diaphragm valve body 30 described later, and an upper surface thereof is formed in a planar shape in order to efficiently receive a pressing force from the valve lift shaft 41. ing. Further, an annular flange portion 23 for projecting and holding a seal member 15 to be described later is provided on the outer periphery of the substantially middle portion of the small diameter portion 21.

  On the other hand, the large-diameter portion 22 is disposed on the ceiling 22a connected to the lower end of the small-diameter portion 21, an inner skirt 22b extending downward from the ceiling 22a, and outside the inner skirt 22b. The outer skirt portion 22c extends downward from the portion 22a. The inner skirt portion 22b is formed longer (in the vertical direction) than the outer skirt portion 22c, and the upper end portion of the first valve closing spring 12 is housed between the inner skirt portion 22b and the outer skirt portion 22c. That is, the first valve closing spring 12 is formed by the ceiling portion 22a of the large diameter portion 22 of the pressure response valve 20 (the portion between the inner skirt portion 22b and the outer skirt portion 22c) and the lower case 10A of the valve body 10 described above. It is shrink | fitted between the level | step-difference part 11 (part inside the positioning part 11a in).

  A rubber seal member 15 is externally mounted on the small diameter portion 21 of the pressure response valve 20. The seal member 15 is formed in a thick disk shape having a slightly smaller diameter than the ceiling portion 22 a of the large diameter portion 22, and is sandwiched between the ceiling portion 22 a of the large diameter portion 22 and the flange portion 23 of the small diameter portion 21. Yes. An annular valve seat 16 with an annular valve port 16a is formed on the outer peripheral end of the upper surface of the seal member 15 so as to come into contact with and separate from an attachment member 32 (a flat plate portion thereof) of a diaphragm valve body 30 described later.

  The uppermost step portion of the lower case 10A is an L-shaped and bowl-shaped diaphragm receiving portion 10a that is laid down in cross section. An annular protrusion 10b is provided on the inner peripheral end of the diaphragm receiving portion 10a so as to protrude upward (diaphragm 31 side).

  An inner cylinder portion 18 into which a pressure adjusting member 45 and the like to be described later are inserted (along the vertical direction) is provided on the inner periphery of the upper step portion of the upper case 10B. The secondary side connection port 8 is provided. Further, the inner periphery of the lower step portion is a diaphragm working chamber 14 for accommodating the diaphragm valve body 30. The inner cylinder portion 18 is positioned coaxially with the accommodation hole 13 of the lower case 10A described above, and the diaphragm valve body 30 is positioned downward (between the inner cylinder portion 18 and the outer cylinder portion 17 of the upper case 10B ( The upper end side of the second valve closing spring 34 energizing in the valve closing direction) is accommodated. That is, the upper end of the second valve closing spring 34 is received by the ceiling portion 10c of the upper case 10B (the portion between the inner cylinder portion 18 and the outer cylinder portion 17).

  The diaphragm valve body 30 includes a rubber diaphragm 31, a flat plate-like attachment member 32 on which the sealing member 15 (the valve seat 16) of the pressure response valve 20 is seated, and a second valve closing spring 34. And a bottomed short cylindrical spring receiver 33 with a central hole for receiving the lower end of the second valve spring, and the second valve-closing spring 34 is mounted between the ceiling portion 10c of the upper case 10B and the spring receiver 33. . The spring receiver 33 is formed of, for example, a stainless material, and also serves as a stopper that determines the rising limit position of the diaphragm 31.

  The outer peripheral portion of the diaphragm 31 is held between the flange-shaped portion 10d provided at the lower end of the upper case 10B and the uppermost diaphragm receiving portion 10a of the lower case 10A. The inner peripheral portion of the diaphragm 31 is held between the contact member 32 and the spring receiver 33. Specifically, in the state where the inner peripheral portion of the diaphragm 31 is interposed between the attachment member 32 (the flat plate portion thereof) and the spring receiver 33 (the bottom portion thereof), the upper end portion of the attachment member 32 (the cylindrical portion thereof) By caulking the formed thin protruding portion to the outside, the diaphragm 31, the attachment member 32, and the spring receiver 33 are integrated.

  The secondary side connection port 8 communicating with the diaphragm working chamber 14 is connected to a connecting pipe 9 for connecting a hose or the like to the outer end (opening), and the intermediate portion (opening formed therein) has an intake air. A valve 50 is attached.

  The intake valve 50 has an intake pipe 52 for sucking the atmosphere into the valve body 10 via the secondary side connection port 8, and the base end of the intake pipe 52 is an intermediate portion of the secondary side connection port 8. It is fitted and connected to (the formed opening) (with an O-ring 54 interposed therebetween). A shielding wall 52d for preventing steam or hot water from the primary side from entering the intake pipe 52 (secondary side connection port 8) is provided at the valve body 10 side portion at the proximal end of the intake pipe 52. (Toward the inside).

  The intake pipe 52 includes a first passage portion 52a that extends substantially vertically from the secondary side connection port 8, and a second passage portion 52b that bends substantially vertically from the tip of the first passage portion 52a, and the second passage portion 52b. The connection tool 53 in which the intake valve port 53b having substantially the same diameter as the second passage portion 52b and the valve body housing chamber 53a having a larger diameter than the second passage portion 52b and the intake valve port 53b are formed is connected to the distal end side of the second passage portion 52b. Yes. The end of the connecting member 53 on the valve body accommodating chamber 53a side is fitted on the tip of the second passage portion 52b of the intake pipe 52 and fixed by, for example, ultrasonic welding, and the valve body accommodating chamber 53a is made of, for example, rubber. A ball valve body 51 is movably accommodated.

  The ball valve body 51 is sucked into the distal end side of the second passage portion 52b or pressed against the intake valve port 53b side according to a pressure change in the relief valve 1 or the like. When the ball valve body 51 is pressed against the intake valve port 53b, the intake valve port 53b is closed. On the other hand, when the ball valve body 51 is sucked into the distal end side of the second passage portion 52b, the inner periphery of the distal end of the second passage portion 52b is arranged so that the second passage portion 52b is not blocked by the ball valve body 51. The standing wall 52c for restricting the movement of the ball valve body 51 toward the second passage portion 52b is provided with an interval of 90 °, for example.

  The relief valve 1 of the present embodiment is incorporated into the hot water supply apparatus in a posture in which the secondary side connection port 8 and the connection tool 53 (the intake valve port 53b) of the intake valve 50 are on the lower side. Accordingly, during normal times, the ball valve body 51 is in a state in which the intake valve port 53b is closed by its own weight. On the other hand, when the pressure on the primary side becomes equal to or lower than the set negative pressure, the ball valve body 51 is sucked up to the standing wall 52c at the tip of the second passage portion 52b by the negative pressure, and the intake valve port 53b is opened. As a result, the external air flows through the intake valve port 53b → the valve body accommodating chamber 53a → the intake pipe 52 (between the standing walls 52c of the second passage portion 52b and the first passage portion 52a) → the secondary side connection port 8. Through the valve body 10. When the outside air is sucked into the valve body 10, the pressure response valve 20 is opened and sucked into the primary side.

  A substantially cylindrical pressure adjusting member 45 is inserted into and screwed into the inner cylindrical portion 18 of the upper case 10B, and a stepped shaft-like valve lift shaft 41 is slidable on the pressure adjusting member 45. It is inserted. The pressure adjusting member 45 and the valve lift shaft 41 are made of, for example, a synthetic resin, and the lower end portion of the pressure adjusting member 45 has a smaller outer diameter than the attachment member 32 (the cylindrical portion thereof) of the diaphragm valve body 30 described above. The inner diameter (the diameter of the lower small-diameter hole 44b) (in other words, the outer diameter of the lower end portion of the valve lift shaft 41) is slightly smaller than the small-diameter portion 21 of the pressure response valve 20 described above.

  More specifically, the pressure adjusting member 45 is inserted into the inner cylindrical portion 18 (in this example, inserted from the lower side), and a male screw portion 45 a provided on the outer periphery of the pressure adjusting member 45 is provided on the inner cylindrical portion 18. It is attached to the inner side of the inner cylinder portion 18 by being screwed into a female screw portion 18a provided in the inner peripheral abdomen. A rubber O-ring as a sealing material is provided between the pressure adjusting member 45 and the inner cylindrical portion 18 (specifically, an annular groove provided below the male screw portion 45a on the outer periphery of the pressure adjusting member 45). 46 is attached. Engaging grooves 47 and 48 for rotating (screw feeding) the pressure adjusting member 45 with respect to the inner cylinder portion 18 (that is, the valve body 10) are provided at the upper end portion and the lower end portion of the pressure adjusting member 45. Is provided. Here, the engagement grooves 47 and 48 are formed in a cross shape or a straight line shape in a plan view, for example.

  Further, the inside of the pressure adjusting member 45 is formed with a step having a relatively large diameter upper large diameter hole 44a and a relatively small diameter lower small diameter hole 44b, and the valve lift shaft 41 has a relatively large diameter. On the lower side of the large-diameter shaft portion 41a, a small-diameter shaft portion 41b that is formed with a relatively small diameter and a relatively long length (in the vertical direction) projects (integrally). The large-diameter shaft portion 41a is slidably inserted into the upper large-diameter hole 44a, and the small-diameter shaft portion 41b is inserted into the lower small-diameter hole 44b so that the valve lift shaft 41 is adjusted. It is arranged inside the pressure member 45 so as to be movable up and down. A rubber O-ring 42 as a sealing material is provided between the valve lift shaft 41 and the pressure adjusting member 45 (specifically, an annular groove provided on the outer periphery of the upper large diameter portion 41a of the valve lift shaft 41). Is installed. A pedestal portion 41c having a slightly wider and substantially rectangular flat plate shape is provided at the upper end portion of the valve lift shaft 41 (the large diameter shaft portion 41a) so as to be brought into contact with the manual operation lever 60 attached above the lift shaft 41. . The pedestal portion 41c is formed wider than the upper end portion of the pressure adjusting member 45. When the manual operation lever 60 is operated (rotated) and the lift shaft 41 is pushed down, the pedestal portion 41c is adjusted. It abuts on the upper end of the pressure member 45 (detailed later).

  The upper part of the inner cylinder part 18 (the part above the female thread part 18a) has an inner shape so as to avoid interference with the pedestal part 41c when the lift valve shaft 41 is pushed down by the operation of the manual operation lever 60. Is formed slightly larger.

  More specifically, between the valve shaft 41 and the pressure regulating member 45, more specifically, the outer peripheral step surface formed between the large diameter shaft portion 41a and the small diameter shaft portion 41b of the valve lifting shaft 41 and the upper portion of the pressure regulating member 45. A compression coil spring 43 that constantly biases the lift shaft 41 upward (to the manual operation lever 60 side) is contracted between an inner circumferential step surface formed between the large diameter hole 44a and the lower small diameter hole 44b. It is disguised.

  The pressure regulating member 45 and the valve lift shaft 41 inserted in the inner cylinder portion 18 are arranged coaxially with the pressure response valve 20 accommodated in the accommodation hole 13, and in a steady state (valve closed state), The pressure response valve 20 is opposed to the upper end of the pressure response valve 20 with a predetermined distance (see FIG. 2).

  Before inserting the valve lift shaft 41 into the pressure adjusting member 45, for example, using a tool such as a plus driver or a minus driver, the pressure adjusting member 45 is inserted into the inner cylinder portion via the engagement groove 47 provided at the upper end portion. 18 (that is, the valve body 10) is rotated to move the pressure regulating member 45 up and down accordingly, and the distance from the bottom surface of the pressure regulating member 45 to the top surface of the pressure response valve 20 is changed (adjusted). Is done. By increasing the distance, the set pressure on the primary side until the pressure response valve 20 is opened can be increased, and by reducing the distance, the set pressure on the primary side until the pressure response valve 20 is opened can be decreased.

  That is, in this example, the female screw portion 18a formed on the inner periphery of the inner cylinder portion 18 of the valve body 10, and the female screw portion 18a formed on the outer periphery of the pressure adjusting member 45 inserted in the inner cylinder portion 18. A pressure adjusting mechanism 49 for adjusting the set pressure on the primary side until the valve opening of the pressure response valve (valve element) 20 is configured by the male screw portion 45a to be screwed together.

  Further, the manual operation lever 60 has a U-shaped surface cut by a virtual plane including the central axis (center line) of the valve lift shaft 41, and a pair of parallel plates of the U-shape. A pair of insertion grooves 61 a that are inclined with respect to the central axis are provided inside the portion 61. A rotating shaft 10f projecting outward from a pair of mounting portions 10e erected on the ceiling portion 10c of the upper case 10B is inserted toward the back of the pair of insertion grooves 61a of the manual operation lever 60, Furthermore, the compression coil spring 43 (biasing force) interposed between the pressure adjusting member 45 and the valve lift shaft 41 causes the upper surface of the pedestal portion 41c of the valve lift shaft 41 to move to the manual operation lever 60 (the pair of flat plates). It is pressed against the lower surface of a substantially rectangular pressing plate portion 62) provided between the portions 61. Thereby, the manual operation lever 60 is rotatably attached to the rotating shaft 10f without the rotating shaft 10f being detached from the insertion groove 61a. In this example, by rotating the manual operation lever 60 clockwise or counterclockwise around the rotation shaft 10f on which the manual operation lever 60 is pivotally supported, the manual operation lever 60 (the pressing plate portion 62) and the valve lift shaft are rotated. 41 (the pedestal portion 41c) and the cam shaft 41 push down the valve shaft 41 (against the urging force of the compression coil spring 43), and the lower end of the valve shaft 41 is the small diameter portion 21 of the pressure response valve 20. The pressure response valve 20 is lowered by contacting the upper end, the valve seat 16 of the seal member 15 of the pressure response valve 20 is separated from the contact member 32 (the lower surface thereof) of the diaphragm valve body 30, and the pressure response valve 20 is opened. It is.

  That is, in this example, the above-described valve lift shaft 41 and the manual operation lever 60 constitute a forced valve opening mechanism 40 that forcibly opens the pressure response valve (valve element) 20.

<Operation of relief valve 1>
The basic opening / closing operation of the relief valve 1 of the present embodiment having the above-described configuration will be outlined below.

[Valve closed]
As shown in FIG. 2, in the steady state (valve closed state), the valve lift shaft 41 (lower end) and the pressure regulating member 45 (lower end) are separated from the upper end of the pressure response valve 20 by a predetermined distance, The lower end of the lift valve shaft 41 is positioned slightly above the lower end of the pressure adjusting member 45.

[Valve open state]
As shown in FIG. 3, when the primary pressure becomes equal to or higher than the set pressure, the diaphragm valve body 30 is pushed up against the urging force of the second valve closing spring 34 by the pressure. On the other hand, the pressure response valve 20 is also pushed up by the pressure and the urging force of the first valve closing spring 12. When the upper end of the small diameter portion 21 of the pressure response valve 20 comes into contact with the lower end of the pressure regulating member 45, the pressure response valve 20 Accordingly, the valve seat 16 of the seal member 15 is separated from the attachment member 32 and the pressure response valve 20 is opened.

  As a result, the steam and hot water from the primary side are connected to the primary side connection port 7 → the receiving hole 13 → the gap between the valve seat 16 and the attachment member 32 → the gap between the small diameter portion 21 and the attachment member 32 → Diaphragm working chamber 14 → discharged to the outside through the secondary side connection port 8. At this time, the ball valve body 51 is pressed toward the intake valve port 53b, and the intake valve 50 is closed.

[Forced valve open state (operation state)]
Further, when the pressure response valve 20 is forcibly opened temporarily (that is, only when the manual operation lever 60 is operated) in an emergency or maintenance check, as shown in FIG. The user holds the manual operation lever 60 and rotates (rotates clockwise in the figure). As a result, the valve lift shaft 41 is pushed down by the cam mechanism between the manual operation lever 60 and the valve lift shaft 41 described above, and the lower end of the valve lift shaft 41 comes into contact with the upper end of the small diameter portion 21 of the pressure response valve 20. The pressure response valve 20 is lowered, the valve seat 16 of the seat member 15 is separated from the attachment member 32, and the pressure response valve 20 is forcibly opened.

  In this example, the movement (amount) of the valve lift shaft 41 associated with the operation of the manual operation lever 60 is limited by the upper end portion of the pressure regulating member 45 mounted on the valve lift shaft 41. . That is, the upper end portion of the pressure adjusting member 45 is a stopper portion that defines a lower movement limit of the valve lift shaft 41 (movement limit of the valve lift shaft 41 with respect to the pressure response valve 20) by the operation of the manual operation lever 60.

  Thereby, the steam and hot water from the primary side are substantially the same as described with reference to FIG. 3, the clearance between the primary side connection port 7 → the receiving hole 13 → the valve seat 16 and the attachment member 32 → the small diameter portion 21. And the contact member 32 → the diaphragm working chamber 14 → the secondary side connection port 8 to be discharged to the outside. When the primary side has a negative pressure and the connecting pipe 9 of the secondary side connection port 8 is connected to the atmosphere, the atmosphere from the outside is reversed from the secondary side connection port 8 to the primary side. When it is sucked into the hot water storage tank through the connection port 7 and the connecting pipe 9 of the secondary side connection port 8 is not connected to the atmosphere, the intake valve port 53b → the valve body storage chamber 53a → the intake pipe of the connection tool 53 52 (between the standing walls 52c of the second passage portion 52b and the first passage portion 52a) → secondary side connection port 8 → diaphragm working chamber 14 → gap between the small diameter portion 21 and the attachment member 32 → valve seat 16 is inserted into the hot water storage tank via the gap between the contact member 16 and the attachment member 32 → the accommodation hole 13 → the primary connection port 7.

[Forced valve open state (hold state)]
Further, when the pressure response valve 20 is forcibly opened and held (held) in an emergency or maintenance check, as shown in FIG. 5, the manual operation lever 60 is rotated (counterclockwise in the figure). Rotate about 90 °). At this time, even if the user releases the hand from the manual operation lever 60, the manual operation lever 60 is not returned to the original position but is held (held) in that state. As a result, the pressure response valve 20 is forcibly opened in the same manner as described with reference to FIG. 4, and steam and hot water from the primary side are discharged to the outside via the same route as that described above. .

<Effect of relief valve 1>
In the relief valve 1 of the present embodiment configured as described above, the forced valve opening mechanism 40 that forcibly opens the pressure response valve (valve element) 20 is movable with respect to the pressure response valve 20. While having the valve shaft 41 distributed and the manual operation lever 60 which acts on the valve shaft 41 to push down the valve shaft 41, the set pressure on the primary side until the pressure response valve 20 is opened is adjusted. The pressure regulating member 45 is screwed onto the valve main body 10 and the manual operation lever 60 does not directly act on the pressure regulating member 45 when the pressure response valve 20 is forcibly opened. Therefore, deformation due to wear or the like of the pressure adjusting member 45 and loosening of the screwing of the pressure adjusting member 45 with respect to the valve body 10 are suppressed, so that a change in the set pressure on the primary side until the pressure response valve 20 is opened is allowed. Can be suppressed.

  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. Changes can be made. For example, it is needless to say that each component constituting the relief valve 1 of the above-described embodiment may be made of an appropriate material other than the above-described materials.

DESCRIPTION OF SYMBOLS 1 Relief valve 7 Primary side connection port 8 Secondary side connection port 10 Valve main body 10A Lower case 10B Upper case 12 First valve closing spring 13 Housing hole 14 Diaphragm working chamber 15 Seal member 16 Valve seat 16a Valve port 17 Outer cylinder part 18 Inner cylinder part 18a Female thread part 20 Pressure response valve (valve element)
21 Small-diameter portion 22 Large-diameter portion 30 Diaphragm valve body 31 Diaphragm 32 Contact member 33 Spring receiver 34 Second valve-closing spring 40 Forced valve-opening mechanism 41 Valve shaft 43 Compression coil spring 45 Pressure-regulating member 45a Male thread portion 47 Engaging groove (Upper end side)
48 Engagement groove (lower end side)
49 Pressure regulating mechanism 50 Intake valve 51 Ball valve body 52 Intake pipe 53 Connector 60 Manual operation lever

Claims (7)

A valve body having a primary side connection port and a secondary side connection port, and disposed between the primary side connection port and the secondary side connection port, and opens when the pressure on the primary side exceeds a set pressure. And a relief valve comprising a valve body for releasing the pressure on the primary side to the secondary side,
In order to forcibly open the valve body, there is a lift valve shaft that is movably disposed with respect to the valve body, and a forcible opening that has a manual operation lever that acts on the valve shaft and pushes down the valve shaft. A valve mechanism is provided,
A relief valve characterized in that a pressure regulating member for adjusting a set pressure on the primary side until the valve body is opened is screwed onto the valve body.   2. The relief valve according to claim 1, wherein the pressure regulating member is inserted and screwed into an inner cylinder portion formed in the valve body along an opening / closing direction of the valve body.   The relief valve according to claim 1 or 2, wherein the pressure regulating member has a cylindrical shape, and the valve lift shaft is slidably inserted into the pressure regulating member.   The relief valve according to claim 3, wherein a compression coil spring is mounted between the pressure regulating member and the lift shaft.   The relief valve according to any one of claims 1 to 4, wherein the pressure regulating member is provided with a stopper portion that defines a movement limit of the valve shaft relative to the valve body.   The relief valve according to claim 5, wherein the stopper portion is provided at an upper end portion of the pressure regulating member.   The relief valve according to claim 6, wherein an engagement groove for rotating the pressure regulating member with respect to the valve body is provided at an upper end portion of the pressure regulating member.

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