JP2014001759A - Relief valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a relief valve capable of incorporating therein an intake valve without a significant increase in the number of part items and man-hours, where the inlet valve is operable to open and close in response to a pressure on a primary side for the case that atmospheric air is not suctioned from the outside even if the pressure on the primary side is decreased to a set negative pressure or less (negative pressure-large).SOLUTION: In the case that atmospheric air is not suctioned from a second connection port 8 even if the pressure on the primary side is decreased to the set negative pressure or less, in the relief valve, a lifting valve stem 40 is provided with an intake passage 45 for suctioning atmospheric air into a valve chamber 22, and the lifting valve stem 40 further includes the intake valve 70 that is configured to automatically open to allow the intake passage 45 to suction atmospheric air from the outside when the pressure on the primary side is decreased to the set negative pressure or less.

Description

  The present invention relates to a relief valve used in a hot water supply device or the like, and in particular, when the pressure on the primary side (for example, in a hot water storage tank) exceeds a set pressure, the valve is opened and the primary side pressure is changed to the secondary side. In addition to the function of releasing the air to the atmosphere (opening to the atmosphere), it also relates to a relief valve that has the function of opening the valve when the pressure on the primary side falls below the set negative pressure (large negative pressure) and sucking the atmosphere to the primary side. .

  Conventionally, as a relief valve, a valve body provided with a valve chamber, a primary side connection port, and a secondary side connection port, and an opening and closing operation according to the pressure on the primary side introduced into the valve chamber from the primary side connection port To open and close the opening / closing operation member, the valve shaft that is slidably inserted into the upper part of the valve body, and to push down the valve operation shaft in order to force the opening / closing operation member to open in an emergency or maintenance inspection A forced valve opening mechanism having a manual operation lever, and the opening / closing operation member is provided when the pressure on the primary side exceeds a set pressure in order to prevent deformation or destruction of the primary side components such as a hot water storage tank. Opening operation releases the primary side pressure to the secondary side, and when the primary side pressure becomes equal to or lower than the set negative pressure, the opening / closing operation member opens and sucks the air from the second connection port to perform the primary operation. The thing which made it inhale to the side is known.

  The primary side connection port is connected to the upper part of the hot water storage tank by a conduit, and the secondary side connection port is connected to a hose whose end is routed to an external drainage port (open to the atmosphere). When the pressure in the hot water tank exceeds the set pressure, steam or hot water in the hot water tank is discharged to the drain through the hose, and the pressure in the hot water tank is below the set pressure negative pressure (the negative pressure is high ), Air is sucked through the hose.

  As the opening / closing operation member, conventionally, for example, as described in the following patent document, it has a protruding shaft portion and a valve body portion provided at a lower portion of the protruding shaft portion, and the upper surface side of the valve body portion is a sealing surface. A negative pressure valve body, a valve seat integrated diaphragm integrally attached with a valve seat with a valve port that contacts and separates from the sealing surface, and a first closing that biases the negative pressure valve body upward (in the valve closing direction). A valve spring and a second valve closing spring that urges the diaphragm downward (in the valve closing direction) are known.

  In this relief valve, during normal times when the pressure in the hot water storage tank is within the allowable range, the diaphragm abuts against a stopper portion provided in the valve body to prevent its lowering, and the sealing surface of the negative pressure valve body is the diaphragm. The valve port is closed by being pressed against the valve seat attached to the.

  On the other hand, when the valve in the hot water storage tank exceeds the set pressure and opens, the diaphragm and the negative pressure valve body first rise together (with the valve closed), and the negative pressure valve body (the shaft part thereof) ) Is in contact with the lower end of the pumping shaft, the lift of the negative pressure valve body is stopped, and the diaphragm is further lifted to open the valve.

  Further, when the pressure in the hot water storage tank becomes equal to or lower than the set pressure (negative pressure), only the negative pressure valve body is pulled down and opened.

JP 2008-138784 A

  In the relief valve as described above, even when the primary side pressure falls below the set negative pressure (negative pressure is large), the situation where the atmosphere cannot be sucked from the outside (for example, the hose connected to the connection port is twisted, foreign matter Etc.) may occur. In preparation for such an emergency situation, conventionally, an intake valve (a kind of check valve) that opens and closes according to the pressure on the primary side is separately manufactured and attached to the valve body.

  However, in the method of separately manufacturing the intake valve and attaching it to the valve body, the number of parts and man-hours are greatly increased, resulting in an increase in cost.

  The present invention has been made in view of the above circumstances, and its purpose is to prepare for a situation where the atmosphere cannot be sucked from the outside even if the pressure on the primary side becomes equal to or lower than the set negative pressure (the negative pressure is large). Another object of the present invention is to provide a relief valve that can incorporate an intake valve that opens and closes according to the pressure on the primary side without increasing the number of parts or man-hours.

  In order to achieve the above object, the relief valve according to the present invention basically includes a valve body provided with a valve chamber, a primary side connection port, and a secondary side connection port, and the valve from the primary side connection port. An opening / closing operation member that opens and closes in response to a primary pressure introduced into the chamber, and a lift shaft that is slidably inserted into the upper portion of the valve body to forcibly open the opening / closing operation member, and A forced valve opening mechanism having a manual operation lever for pushing down the lift shaft, and a function of releasing the primary side pressure to the secondary side when the primary side pressure becomes equal to or higher than a set pressure, and the primary side An intake passage for sucking air into the valve chamber in the lift shaft, having a function of sucking air from the second connection port and sucking it into the primary side when the pressure of the air becomes equal to or lower than a set pressure Is provided, and when the pressure on the primary side of the lift valve shaft falls below the set negative pressure An intake valve for intake air into the intake passage is characterized in that provided automatically from the outside opened.

Preferably, the intake valve closes the intake valve port when the pressure on the primary side exceeds a set pressure, and closes the intake valve port when the pressure on the primary side is less than the set pressure. An open ball valve body; and a valve body housing chamber provided between one end of the intake passage and the intake valve port.
The ball valve body is preferably made of rubber.

  In the relief valve according to the present invention, the air is sucked into the valve main body into the valve body in preparation for a situation where the air cannot be sucked from the outside even if the pressure on the primary side is equal to or lower than the set negative pressure (the negative pressure is large). An intake valve is integrated with the valve lift shaft to close the intake passage during normal (normal) operation and automatically open the intake passage when the pressure on the primary side falls below the set negative pressure Therefore, as compared with the conventional case where an intake valve is separately manufactured and attached to the valve body as in the prior art, the number of parts and man-hours can be greatly reduced, and the cost can be reduced.

The longitudinal cross-sectional view which shows one Example of the relief valve which concerns on this invention. FIG. 2 is a partial cutaway view of the relief valve shown in FIG. 1 (a portion with a central angle of 90 degrees in a plan view). The top view of the relief valve shown by FIG. The lower case of the relief valve shown by FIG. 1 is shown, (A) is a top view, (B) is BB sectional drawing of (A). The double-sided sealing member of the relief valve shown by FIG. 1 is shown, (A) is AA arrow sectional drawing of FIG. 1, (B) is XX sectional drawing of (A). The figure used for description of adjustment of the set load of the 2nd valve closing spring of the relief valve shown in FIG. The manual operation lever of the relief valve shown by FIG. 1 is shown, (A) is a three-view figure, (B) is a figure with which it uses for description at the time of an assembly | attachment. The side view with which it uses for operation | movement description of the manual operation lever of the relief valve shown by FIG. FIG. 6 is a three-side view showing a modification of the manual operation lever of the relief valve shown in FIG. FIG. 2 shows the vicinity of the intake valve of the relief valve shown in FIG. The figure which is provided for description of the assembly posture of the relief valve shown in FIG. FIG. 2 is a longitudinal sectional view for explaining the operation of the relief valve shown in FIG. 1 (when the pressure on the primary side becomes equal to or higher than a set pressure). FIG. 2 is a longitudinal sectional view for explaining the operation of the relief valve shown in FIG. 1 (when the pressure on the primary side becomes equal to or lower than a set negative pressure). FIG. 2 is a longitudinal sectional view for explaining the operation of the relief valve shown in FIG. 1 (when a forced valve opening mechanism is operated). FIG. 2 is a longitudinal sectional view for explaining the operation of the relief valve shown in FIG. 1 (when the intake valve is opened).

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing an embodiment of a relief valve according to the present invention, FIG. 2 is a partially cutaway perspective view (a portion having a central angle of 90 degrees in plan view), and FIG. 3 is a plan view. .

  The illustrated relief valve 1 includes a valve body 10, a negative pressure valve body 25 and a diaphragm valve body 30 as opening and closing operation members that open and close according to the pressure on the primary side, a double-sided seal member 50, a lift shaft 40 and a manual operation. And a forced valve opening mechanism 60 including an operation lever 65 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 stage, and the upper case 10B has a cylindrical shape with a large step toward the lower stage, and is provided at four locations on the lower end surface of the upper case 10. The screwing portion 10c (FIG. 3) is fastened and fixed to the screwing portions 10d (FIG. 4) provided at four positions on the upper end surface portion of the lower case 10A with, for example, tapping screws 39.

  As can be understood with reference to FIG. 4, the lower case 10 </ b> A is provided with a mounting hole 13 into which the double-sided seal member 50 is fitted, and a bottom portion 13 b of the mounting hole 13 in the middle step and the lower step. An insertion hole 11 is provided in the opening. The lower part of the insertion hole 11 (the lower part of the lower case 10A) is a primary side connection port 7 connected by a conduit to the primary side (upper part of the hot water storage tank), and the upper part of the insertion hole 11 is a negative pressure valve body. 25 is a valve body working chamber 19 into which the lower cylindrical portion 25a is loosely inserted. An elongated plate-shaped spring receiver 17 that receives the lower end of the first valve closing spring 28 that urges the negative pressure valve body 25 upward is installed at the lower end of the valve body working chamber 19 (intermediate portion of the insertion hole 11). ing.

  In the middle part of the lower case 10A (the outer peripheral side of the valve element working chamber 19), four vertical groove passages 15 having a fan shape in a plan view opened at the inner peripheral side are provided at intervals of 90 degrees.

  Further, the uppermost portion of the lower case 10A is an L-shaped diaphragm-shaped diaphragm receiving portion 10a that has an L-shaped cross section, and an annular protruding portion 10b is projected from the inner peripheral end of the diaphragm receiving portion 10a. Yes.

  As shown in FIG. 5, the double-sided seal member 50 fitted into the mounting hole 13 of the lower case 10 </ b> A is vertically symmetrical, and has a stepped annular synthetic resin frame-like portion 51, It is composed of a thick disc-shaped rubber seal portion 52 integrally formed by pouring a molten rubber material into the peripheral side.

  A central communication port 55 is formed at the center of the rubber seal portion 52. The lower surface of the rubber seal portion 52 is a lower seal surface 5A where the valve seat 27 of the negative pressure valve body 25 contacts and separates, and the upper surface thereof is an upper seal surface 5B where the valve seat 37 of the diaphragm valve body 30 contacts and separates. Yes.

  On the upper and lower sides on the inner peripheral side of the frame-like portion 51, four convex portions 51d each having an arc shape in plan view are provided so as to protrude by 90 degrees.

  The frame-shaped portion 51 is provided with four longitudinal through passages 56 each having a fan-shaped cross section at intervals of 90 degrees so as to penetrate in the vertical direction. On the inner peripheral side of the upper and lower end portions of the longitudinal communication passage 56, a cross-sectional fan-shaped horizontal passage 56a is formed so that the side surface is defined by adjacent convex portions 51d.

  Note that the double-sided seal member 50 is made vertically symmetrical for convenience and the like when assembled to the lower case 10A.

  The double-sided seal member 50 having such a configuration is fitted into the mounting hole 13 of the lower case 10A and fixed by ultrasonic welding.

  On the inner periphery of the upper stage part (outer cylinder part 16) of the upper case 10B, an inner cylinder part 18 into which a valve shaft 40 (a rod-like part 40A) described later is slidably fitted is provided. A secondary connection port 8 is provided to which a hose is connected from the center of the upper part to the lower part. Further, the inner periphery of the lower stage is a diaphragm working chamber 14.

  A portion between the outer cylinder portion 16 and the inner cylinder portion 18 of the upper case 10B serves as a housing chamber for the second valve closing spring 38 that urges the diaphragm valve body 30 downward (in the valve closing direction).

  The negative pressure valve body 25 has a lower cylindrical portion 25a and a protruding shaft portion 25b having a T-shaped cross section protruding upward from the center of the ceiling portion 25c of the lower cylindrical portion 25a. A first valve seat 27 with an annular first valve port 26 that contacts and separates from the lower seal surface 5A of the double-sided seal member 50 is provided.

  The diaphragm valve body 30 includes a rubber diaphragm 32, a stepped cylindrical valve body constituting member 35, and a bottomed short cylindrical spring receiver 33 with a central hole that receives the lower end of the second valve closing spring 38. ,have. The spring receiver 33 also serves as a stopper that determines the rising limit position of the diaphragm 32 (see FIG. 12). The outer peripheral portion of the diaphragm 32 is held between the flange-shaped portion 10g provided at the lower end portion of the upper case 10b and the diaphragm receiving portion 10a of the lower case 10B.

  The valve body constituting member 35 is provided with a second valve seat 37 with a second valve port 36 that contacts and separates from the upper seal surface 5B of the double-sided seal member 50 on the inner peripheral side thereof.

  The inner peripheral portion of the diaphragm 32 is sandwiched and held by the valve body constituting member 35 and the spring receiver 33. Specifically, the diaphragm 32, the valve body constituent member 35, and the spring receiver 33 are integrated by caulking a thin protruding portion formed on the inner peripheral side of the valve body constituent member 35.

  In the present embodiment, a mechanism (screw portion or the like) for adjusting the set load of the second valve closing spring 38 that is compactly mounted between the ceiling portion 10f of the upper case 10B and the spring receiver 33 is not provided. The load is kept within an allowable range by strictly controlling the dimensions of each part. In the case where it does not fall within the allowable range, for example, as shown in FIG. 6, a washer 67 is sandwiched between the ceiling portion 10 f of the upper case 10 </ b> B and the upper end of the second valve closing spring 38.

  In the relief valve 1 of the present embodiment having the above-described configuration, the lower chamber 21 is defined below the double-sided seal member 50, and the upper chamber 22 is defined above the diaphragm valve body 30, and the double-sided seal member A pressure sensitive chamber 23 is defined between 50 and the diaphragm valve body 30.

  Next, a forced valve opening mechanism 60 having a valve lift shaft 40 and a manual operation lever 65 for forcibly opening the negative pressure valve body 25 will be described.

  The lift shaft 40 is made of synthetic resin, and is folded sideways from the rod-like portion 40A slidably fitted into the inner cylinder portion 18 (the guide hole 42 portion) of the upper case 10B and the upper end portion of the rod-like portion 40A. It has a horizontal side portion 40B that bends and a hook-like portion 44 provided near the upper end of the rod-like portion 40A, and the lower portion of the rod-like portion 40A protrudes further downward from the lower end of the inner cylinder portion 18, and the lower end surface thereof is The upper end surface of the protruding shaft portion 25b of the negative pressure valve body 25 is opposed to the negative pressure valve body 25 with a slight gap.

  The lift valve shaft 40 is compressed between the bottom portion of the spring receiving hole 43 formed in the upper portion of the inner cylindrical portion 18 of the upper case 10B (stepped portion with the guide hole 42) and the flange portion 44. The coil spring 48 is always urged upward, and is latched and locked by a manual operation lever 65 pressed against the flange 44.

  An annular groove 49 having a long axial direction (vertical direction) is formed in the lower part of the rod-like part 40A of the lift shaft 40 (the part fitted in the guide hole 42). A ring 47 is attached. The reason why the width of the annular groove 49 is increased is that the valve shaft 40 can be pushed down without the O-ring 47.

  The manual operation lever 65 pushes down the lift shaft 40 by utilizing this principle, and as shown in FIG. 7A, a side view is obtained by bending one metal wire. It is made in a roughly key shape.

  Specifically, the manual operation lever 65 includes a U-shaped gripping portion 65a extending in the front-rear direction, an upright portion 65b bent strongly 90 degrees downward so as to draw an arc from both ends of the U-shaped gripping portion 65a, and the upright portion 65b. A lower side portion 65c that bends in the front-rear direction so as to draw an arc, a laterally inclined L-shaped side portion 65d that bends outward in the left-right direction from the lower side portion 65c, and a pin that extends further outward in the left-right direction from the lateral side portion 65d It consists of a shaft part 65e, and the lower side part 65c is brought into pressure contact with the flanged part 44 of the valve shaft 40 in a normal state.

  The pin shaft portion 65e of the manual operation lever 65 is rotatably fitted in a bearing hole 63 provided in a pair of left and right support columns 62 protruding upward from the ceiling portion 10f of the upper case 10B. In order to insert the pin shaft portion 65e into the bearing hole 63, as shown in FIG. 7 (B), the opposite side of the U-shaped gripping portion 65a is gripped with a finger and the width thereof is narrowed. That's fine.

  As described above, the manual operation lever can be assembled very easily and easily as compared with the case where the manual operation lever is made of sheet metal.

  Needless to say, the gripping portion 65a may have another shape such as a pull tab shape (65a ') like the manual operation lever 65' shown in FIG.

  In the forced valve opening mechanism 60 configured as described above, when the negative pressure valve body 25 is forcibly opened, the handle 65a of the manual operation lever 65 is held counterclockwise as shown in FIG. Rotate around 90 degrees. As a result, the handle portion 65a serves as a force point and the pin shaft portion 65e serves as a fulcrum, and the operating point shifts from the lower side portion 65c to the upright portion 65b, whereby the lift shaft 40 is pushed down, and the lower end of the lift shaft 40 is a negative pressure valve. The negative pressure valve body 25 is pushed down in contact with the upper end of the protruding shaft portion 25b of the body 25. Thereby, the valve seat 27 of the negative pressure valve body 25 is separated from the lower seal surface 5A of the double-sided seal member 50, and the negative pressure valve body 25 is forcibly opened.

  In addition to the above configuration, in the relief valve 1 of the present embodiment, a situation in which the atmosphere cannot be sucked from the second connection port 8 even when the pressure on the primary side becomes equal to or lower than the set negative pressure (the negative pressure is large) (for example, the second pressure) In preparation for the case where the hose connected to the connection port 8 is twisted or clogged with foreign matter, the following measures are taken.

  That is, an intake passage 45 for sucking air into the valve body 10 is provided in the lift shaft 40, and the intake passage 45 is closed to the intake passage 45 in a normal time (normal time) so that the pressure on the primary side There is provided an intake valve 70 that automatically opens the intake passage 45 in the event of an abnormality in which becomes below the set negative pressure.

  The intake passage 45 includes a vertical passage portion 45a provided in the rod-like portion 40A of the lift shaft 40, and a horizontal passage portion 45b that is bent laterally from the upper end of the vertical passage portion 45a. An intake valve 70 is provided on the end side.

  The intake valve 70 has a rubber ball valve body 75 and is integrated with the lateral side portion 40B of the valve lift shaft 40. That is, the connection tool 71 in which the intake valve port 72 having the same diameter as that of the lateral passage portion 45b is fixed to the outer end portion of the lateral side portion 40B by ultrasonic welding. A lateral passage portion that guides the ball valve body 75 movably in the opening and closing direction of the intake valve port 72 between the outer end 45c of the lateral passage portion 45b and the inner end portion of the intake valve port 72 in the lateral side portion 45B. A valve body accommodating chamber 73 having a diameter larger than that of 45b and the intake valve port 72 is provided. Further, on the outer peripheral side of the outer end portion 45c of the horizontal passage portion 45b, as shown in FIG. 10 (C), the air passage 45b is closed even when the outer end portion 45c of the horizontal passage portion 45b is closed by the ball valve body 75. So as to be able to be sucked into the valve main body 10, four expansion passages 76 having a fan shape in a plan view opened on the inner peripheral side are provided at intervals of 90 degrees.

  Here, as shown in FIG. 11, the relief valve 1 of the present embodiment is incorporated into the hot water supply apparatus in such a posture that the secondary side connection port 8 and the intake valve 70 are on the lower side. Accordingly, during normal time (normal time), as shown in FIG. 10A, the ball valve body 75 closes the intake valve port 72 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, as shown in FIG. 10B, the ball valve body 75 is sucked up to the outer end 45c of the lateral passage portion 45b by the negative pressure. Then, the intake valve port 72 is opened. As a result, the outside air is sucked into the valve body 10 (the upper chamber 22) through the intake valve port 71 → the valve body accommodating chamber 73 → the expansion passage 76 → the intake passage 45 (when this abnormality occurs, as described later) The intake valve body 25 is opened).

  In the relief valve 1 of the present embodiment having such a configuration, when the primary pressure becomes equal to or higher than the set pressure, the diaphragm valve body 30 is attached to the second valve closing spring 38 as shown in FIG. The second valve seat 37 is pushed up against the force to move away from the upper seal surface 5B, the diaphragm valve body 30 is opened, and the steam and hot water from the primary side are connected to the primary side connection port 7 → the lower chamber 21 → the longitudinal groove passage. 15 → Lower side passage 56a → Double side communication passage 56 → Upper side passage 56a and pressure sensing chamber 23 → Gap formed between the second valve seat 37 and the upper seal surface 5B → Second valve It is discharged to the outside through the port 36 → the upper chamber 22 → the secondary side connection port 8 → the hose.

  On the other hand, when the pressure on the primary side becomes equal to or lower than the set negative pressure (the negative pressure is large), as shown in FIG. 13, the diaphragm valve body 30 remains closed and the negative pressure valve body 25 is pulled down, so that the negative pressure valve The first valve seat 27 of the body 25 is separated from the lower seal surface 5A, the negative pressure valve body 25 is opened, and the atmosphere from the outside is sequentially connected to the secondary side connection port 8 → the upper chamber 22 → the second valve port 36 → the central communication. It is sucked into the hot water storage tank through the opening 55 → the gap formed between the first valve seat 27 and the lower seal surface → the lower chamber 21 → the primary connection port 7. In this case, depending on the magnitude of the negative pressure on the primary side, the intake valve 70 may open, and in this case, atmospheric suction is performed through the intake passage 45.

  On the other hand, in order to forcibly open the negative pressure valve body 25 in an emergency or maintenance inspection, as shown in FIG. Turn it. Thereby, the valve lift shaft 40 is pushed down, the lower end of the valve lift shaft 40 comes into contact with the upper end of the protruding shaft portion 25b of the negative pressure valve body 25, and the negative pressure valve body 25 is pushed down.

  As a result, the valve seat 27 of the negative pressure valve body 25 is separated from the lower seal surface 5A, and the negative pressure valve body 25 is forcibly opened. Steam or hot water from the primary side is connected to the primary side connection port 7 → the lower chamber 21 → the longitudinal groove passage 15 → the gap formed between the first valve seat 27 and the lower seal surface → the central communication port 55 → the second It is discharged to the outside through the valve port 36 → the upper chamber 22 → the secondary side connection port 8 → the hose. In addition, when the primary side is a negative pressure, air from the outside is connected to the secondary side connection port 8 → the upper chamber 22 → the second valve port 36 → the central communication port 55 → the first valve seat 27 and the lower seal surface. It is sucked into the hot water storage tank through the gap formed therebetween → the lower chamber 21 → the primary side connection port 7.

  In addition to the above, for example, even if the hose connected to the second connection port 8 is twisted or clogged with foreign matter, the second connection port even if the primary pressure falls below the set negative pressure (the negative pressure is large) When an abnormal situation in which the atmosphere cannot be sucked from 8 occurs, the negative pressure valve body 25 is open, and therefore, as shown in FIG. 15 (FIG. 10 (B)), the ball valve body 75 is moved by the negative pressure to the lateral passage portion 45b. Is sucked up to the outer end 45c of the valve, and the intake valve port 72 is opened. As a result, the outside air is sucked into the valve body 10 (the upper chamber 22) through the intake valve port 71 → the valve body accommodating chamber 73 → the bypass passage 76 → the intake passage 45, and thereafter, from the second connection port 8. As in the case of sucking air, the upper chamber 22 → the second valve port 36 → the central communication port 55 → the gap formed between the first valve seat 27 and the lower seal surface → the lower chamber 21 → the primary side It is sucked into the hot water storage tank through the connection port 7.

  In the relief valve 1 of this embodiment having such a configuration, the diaphragm valve body 30 and the negative pressure valve body 25 are opened and closed independently, and the double-sided seal member 50 and the diaphragm valve body 30 The primary side pressure is opened when the pressure on the primary side becomes equal to or higher than the set pressure, and the primary side pressure is released to the secondary side. With the double-sided seal member 50 and the negative pressure valve body 25, the primary side pressure is Since the valve is opened when the pressure becomes lower than the set negative pressure and the air is sucked into the primary side, the design flexibility of each part including the diaphragm valve body 30 and the negative pressure valve body 25 is remarkably increased. For example, the diameter of the first valve port 26 on the negative pressure valve body 25 side and the diameter of the second valve port 36 on the diaphragm valve body 30 side can be set to different dimensions. Conflicts that couldn't be met That can also meet each request, as a result, it is possible to provide a high relief valve in performance and quality than those of conventional low cost.

  Conventionally, the momentum of steam or hot water coming from the primary side is directly received by the diaphragm. However, in the relief valve 1 of this embodiment, a double-sided seal member is provided between the primary side connection port 7 and the diaphragm valve body 30. 50, and the flow path from the primary side connection port 7 to the diaphragm valve body 30 is formed in a complicated manner (the lower chamber 21 → the longitudinal groove passage 15 → the lower side passage 56a of the double-sided seal member 50 → Therefore, even if the pressure on the primary side changes suddenly, the impact of the pressure change is absorbed by the flow path wall and is not easily transmitted to the diaphragm valve body 30. Therefore, the undesired behavior of the diaphragm valve is suppressed and leakage is less likely to occur.

  Further, the manual operation lever 65 of this embodiment is produced by bending a single metal wire, so that it is extremely simple compared to a conventional sheet metal, and the valve body 10 can be connected to the valve body 10. Assembling only requires grasping the anti-grip part side of the U-shaped grip part 65a with a finger, narrowing its width and inserting the pin shaft part 65e into the bearing hole 63. Parts cost and assembly cost can be greatly reduced.

  In addition, in the present embodiment, in order to prepare for a situation where the atmosphere cannot be sucked from the second connection port 8 even when the primary side pressure is equal to or lower than the set negative pressure (the negative pressure is large), The main body 10 is provided with an intake passage 45 for inhaling, and the intake passage 45 is closed during normal (normal) time, and the intake passage 45 is automatically opened when the primary side pressure becomes lower than a set negative pressure. Since the intake valve 70 is provided integrally with the valve lift shaft 40 (lateral side portion 40B), an intake valve (the structure of which is well known) is separately prepared as in the prior art. Compared with the case of attaching to the valve body, the number of parts and man-hours can be greatly reduced, and the cost can be reduced.

  Furthermore, in the present embodiment, the first valve closing spring 28 is accommodated inside the lower cylindrical portion 25a of the negative pressure valve body 25, and steam and hot water are supplied to the lower cylindrical portion 25a as shown by arrows in FIGS. Therefore, the first valve closing spring 28 is not significantly affected by steam and hot water. As a result, corrosion and deterioration of the first valve closing spring 28 are reduced, vibration is suppressed, and noise is reduced. And durability can be improved.

  The outer diameter of the lower cylindrical portion 25a is made smaller than the inner diameter of the first valve closing spring 28, and a flange portion is formed on the outer side of the ceiling portion 25c so as to be sandwiched between the flange portion and the spring receiver 17. Naturally, the first valve closing spring 28 may be provided outside the lower cylindrical portion 25c. That is, the first valve closing spring 28 is expanded and contracted using the outer peripheral portion of the lower cylindrical portion 25a as a guide.

  In addition, although the ball valve body 75 has been described as being made of rubber, the present invention is not limited to this and may be made of resin or metal.

DESCRIPTION OF SYMBOLS 1 Relief valve 7 Primary side connection port 8 Secondary side connection port 25 Negative pressure valve body 26 First valve port 28 First valve closing spring 30 Diaphragm valve element 36 Second valve port 38 Second valve closing spring 40 Lifting shaft 45 Intake Passage 50 Double-side seal member 5A Lower seal surface 5B Upper seal surface 55 Central communication port 56 Longitudinal communication passage 60 Forced valve opening mechanism 65 Manual operation lever 70 Intake valve 75 Ball valve body

Claims (3)

A valve body provided with a valve chamber, a primary side connection port, and a secondary side connection port; an opening / closing operation member that opens and closes according to a primary pressure introduced from the primary side connection port into the valve chamber; A lift valve shaft slidably fitted in the upper part of the valve main body to forcibly open the opening / closing operation member, and a forced valve opening mechanism having a manual operation lever for pushing down the valve lift shaft. The function of releasing the primary side pressure to the secondary side when the primary side pressure becomes higher than the set pressure, and the air is sucked from the second connection port when the primary side pressure becomes lower than the set pressure. And a relief valve that has the function of inhaling to the primary side.
An intake passage for sucking air into the valve chamber is provided in the valve lift shaft, and the valve lift valve shaft is automatically opened when the pressure on the primary side falls below a set negative pressure. A relief valve comprising an intake valve for sucking air into the intake passage from outside.   The intake valve is a ball valve that closes the intake valve port when the pressure on the primary side exceeds a set pressure, and opens the intake valve port when the pressure on the primary side is less than the set pressure. The relief valve according to claim 1, further comprising: a body, and a valve body storage chamber provided between one end of the intake passage and the intake valve port.   The relief valve according to claim 2, wherein the ball valve body is made of rubber.

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