JP5512308B2 - Pressure release valve - Google Patents

Description

  The present invention relates to a pressure release valve that opens when a fluid pressure exceeds a certain value to release the pressure. The pressure relief valve of the present invention is used, for example, as a pressure relief valve for an electric water heater, or used in equipment that requires a pressure relief for water. The release valve of the present invention is used as a pressure release valve for a fuel cell, for example.

  FIG. 9 shows a conventional pressure release valve of this type (see Patent Document 1 and the like). As the structure or function of this release valve, when the primary side pressure is received by the diaphragm 51, the diaphragm is used. The valve seat 53 is lifted in the opening direction against the load of the spring 52 that biases 51. Since the position of the valve body 54 cannot be moved from a certain position due to the restriction of the upper shaft 55, the valve portion is opened when the primary side pressure exceeds a certain value (abnormal increase in hot water tank internal pressure), and the primary side pressure is increased. Can be kept below a certain value. Further, in order to forcibly open the valve portion manually, the valve body 54 itself is moved in the opening direction by the load transmitted through the shaft 55 by operating the lever 56, so that there is no pressure receiving load of the diaphragm 51 and the valve seat. Even when the position of the portion 53 is in an unloaded state, the valve portion can be opened.

However, in the above prior art, the inner peripheral edge portion of the diaphragm 51 that receives the primary pressure is configured to be caulked and held by the caulking portion 58 of the center plate 57 that forms the valve seat portion 53. Since a spring retainer 59 which is a separate part is disposed on the outer peripheral side of the portion 58 and the spring retainer 59 is configured to receive one end of the spring 52,
(1) The degree of freedom of the set size of the spring 52 is small (the diameter of the spring 52 must be set larger than the diameter of the caulking portion 58, and therefore much larger than the inner diameter of the diaphragm 51. )
(2) A space 62 that is a part of the inflow chamber 61 that communicates with the inflow port 60 and is located below the diaphragm 51 in the drawing is not effectively utilized as a dead space.
(3) Since the center plate 57 is in contact with the stopper portion 64 provided on the inner surface of the casing 63, the stroke limit of the valve seat portion 53 is defined. Durability against (impact) is required,
(4) The diaphragm 51 is prevented from rotating with respect to the casing 63 by being sandwiched between the pair of upper and lower casings 63 at the outer peripheral edge thereof, but the diaphragm 51 is sufficiently prevented from rotating with respect to the casing 63 at the inner peripheral edge thereof. It has not been. Therefore, when torque acts on the inner peripheral edge, the diaphragm 51 may be twisted.
There are inconveniences such as.

JP 2008-138784 A

  In view of the above points, the present invention has an automatic valve opening function (a function for automatically opening the pressure when the primary side pressure exceeds a certain value and releasing the pressure) and a forced valve opening function, as in the prior art. In a pressure release valve equipped with a function that can be manually and forcibly opened regardless of the pressure level, it is possible to increase the degree of freedom of the set size of the spring and to effectively use the dead space of the inflow chamber. An object is to provide a pressure relief valve that can be used. In addition to this, since the center plate does not directly contact the stopper portion, the center plate is not required to have durability against a collision, and the inner peripheral edge portion of the diaphragm is sufficiently prevented from being twisted to generate the twist. The diameter of the poppet that holds the valve body can be increased to increase its strength, and even if the spring is compressed to its limit, fluid can be circulated inside or outside, or an adjustment screw can be attached to the casing. An object of the present invention is to provide a pressure regulating valve that can sufficiently prevent rotation.

In order to achieve the above object, a pressure relief valve according to claim 1 of the present invention includes a casing provided with an inflow port and an outflow port for fluid, an inflow chamber communicating with the inflow port through an internal space of the casing, and an outflow port. An annular diaphragm arranged so as to divide into an outflow chamber that communicates, and an annular protrusion-shaped valve seat that is fixed to the inner peripheral edge of the diaphragm and is provided integrally at the end on the inflow chamber side , and its outer peripheral surface An annular and cylindrical center plate integrally provided with an annular flange-like spring retainer positioned on the outflow chamber side, a poppet disposed on the inner peripheral side of the center plate so as to be axially displaceable, and the poppet is held in an end portion of the inflow chamber side, a valve body which is capable separable and the valve seat while being positioned to face the valve seat, arranged in the outflow chamber side of the poppet Wherein together with a piston displaceably held in rotatably and axially in the circumferential direction by a bearing portion provided on the casing, it is interposed between the spring retainer and the casing, provided with the valve seat a spring for elastically urging the center plate to the valve body, a male screw portion provided at the end opposite to the poppet in the piston, relative to the casing with screwed to the male screw portion An adjustment screw that can be displaced in the axial direction, and is disposed outside the casing and is swung. When the swinging operation is performed, the adjustment screw, piston, poppet, and valve body are displaced in one axial direction. said valve body and having a forced valve opening lever to separate from the valve seat, at the inflow chamber screwed nut on the outer periphery of said center plate Te, By the spring retainer and the nut of the serial center plate and having a structure for holding and clamping the inner peripheral edge portion of the diaphragm.

  The pressure relief valve according to claim 2 of the present invention is the pressure relief valve according to claim 1, wherein the nut is urged by the spring when the center plate strokes toward the valve body. A structure is provided in which one end of the stroke is defined by abutting against a stopper portion set inside the casing.

The pressure relief valve according to claim 3 of the present invention is the pressure relief valve according to claim 1 or 2, wherein the nut is a hexagonal nut and is located at a target position of 180 degrees out of the six outer peripheral surfaces of the hexagonal nut. A two-sided inner peripheral plane having a width equivalent to the width of the two sides is provided on the inner surface of the casing, and a detent of a two-sided width structure is provided between the nut and the casing by engaging them with each other. It is characterized by being.

The pressure relief valve according to claim 4 of the present invention is the pressure relief valve according to claim 1, 2, or 3, wherein the poppet has an outward hook-like spring engaging portion at the piston side end portion. An inwardly hooked spring engaging portion is provided on the inner peripheral surface of the center plate and is provided on the inflow chamber side of the engaging portion, and a return spring is interposed between the engaging portions. A groove extending in the axial direction on the inner peripheral side of the return spring and extending in the axial direction on the outer peripheral portion of the poppet for guiding the fluid that has passed between the valve seat and the valve body to the outflow chamber. Or a through hole extending in the axial direction .

The pressure relief valve according to claim 5 of the present invention is the pressure relief valve according to claim 1, 2, or 3, wherein an annular spring receiving surface for holding the other end of the spring is provided on the inner surface of the casing. In addition, a radial flow path for guiding fluid from the inner peripheral side to the outer peripheral side of the spring is provided in the spring receiving surface in a concave shape .

The pressure relief valve according to claim 6 of the present invention is the pressure relief valve according to claim 1, 2, or 3, wherein a second return spring is provided between the bearing portion and the adjusting screw in the casing. The adjustment screw is prevented from rotating with respect to the casing. For this reason, the bearing portion of the casing is provided with a convex portion on the circumference toward the adjustment screw and correspondingly a circle on the adjustment screw. A part of the circumference is provided in the recess, and the rotation prevention structure of the adjustment screw with respect to the casing is provided by the engagement of the protrusion and the recess.

  In the pressure relief valve of the present invention having the above-described configuration, a spring retainer portion that is disposed in the outflow chamber and that holds one end of the spring is integrally provided on the outer peripheral portion of the center plate, and is provided on the outer peripheral portion of the center plate in the inflow chamber. A nut is screwed together, and the inner peripheral end of the diaphragm is sandwiched and held by the spring retainer and the nut. Therefore, in comparison with the above-described prior art, the caulking portion is omitted from the center plate, and the spring retainer portion is disposed at the position where the caulking portion exists, and accordingly, a small-diameter spring can be installed. In addition, since the nut is arranged in a part of the inflow chamber, which is a dead space in the past, this space can be effectively used. As the nut has a space, it is possible to use a commercially available product that is easily available.

  The nut is arranged on the stroke front side of the inner peripheral edge of the diaphragm when the center plate is urged by the spring to make a stroke toward the valve body. Therefore, the nut is configured so that one end of the stroke is defined by coming into contact with a stopper set inside the casing, so that the nut is replaced with one end of the stroke in place of the center plate in the prior art. Accordingly, the center plate is not required to have durability against contact (contact).

  In addition, hexagon nuts are widely known as nuts, and hexagon nuts have six outer peripheral surfaces. Therefore, in order to set a detent for a two-sided width structure using two of the 180-degree symmetrical positions. Convenient. Therefore, in the present invention, a two-side width structure detent is provided between the hexagon nut and the casing, thereby sufficiently derotating the inner peripheral edge of the diaphragm.

  The present invention also proposes the following open valve structure.

  A return spring is interposed between the center plate and the poppet on the inner peripheral side of the center plate, and on the inner peripheral side of the return spring and on the circumference of the outer peripheral portion of the poppet, a valve seat and a valve body An axial flow path is provided for guiding the fluid that has passed through to the outflow chamber. According to this structure, the axial flow path may be a groove-shaped flow path extending in the axial direction, so that the poppet is enlarged in diameter, so that the strength of the poppet can be increased, and the poppet material is not a conventional metal. It is also possible to use a relatively lightweight resin.

  An annular spring receiving surface for holding the other end of the spring is provided on the inner surface of the casing, and a radial flow path for guiding fluid from the inner peripheral side to the outer peripheral side of the spring on a part of the circumference of the spring receiving surface Is provided. According to this structure, even if the coiled spring is compressed to the limit and the gap between the pitches is closed, the fluid can be circulated inside and outside the spring via the radial flow path. It becomes possible to prevent becoming a factor.

  The adjustment screw is prevented from rotating with respect to the casing, and in order to realize this rotation prevention, a convex part of the circumference is provided on the bearing part of the casing toward the adjustment screw, and a part of the circumference of the adjustment screw is correspondingly provided. The concave portion is provided, and the protrusion and the concave portion are engaged with each other to provide a structure for preventing the adjustment screw from rotating relative to the casing. According to this structure, when adjusting the spring load of the spring with a jig in order to adjust the spring load of the spring, the adjustment screw is not rotated, so that the adjustment accuracy of the spring load can be stabilized. It becomes.

  The pressure relief valve according to claim 4 of the present invention is a so-called drainage spring, that is, a so-called drainage spring, wherein the above-mentioned “spring that elastically biases the center plate provided with the valve seat toward the valve body” has a spring action. 1) and the above-mentioned “return spring”, a plurality of the latter return springs may be installed. In this case, one of them is the inner peripheral side of the center plate, and the center plate and poppet It is preferable to install between the bearing portion and the adjusting screw in the casing.

  The present invention has the following effects.

  That is, in the pressure release valve of the present invention, as described above, the inner peripheral edge of the diaphragm is sandwiched and held between the spring retainer integrally formed with the center plate and the nut screwed to the center plate. The degree of freedom of the set size of the spring can be increased, and the dead space of the inflow chamber can be effectively utilized. If a commercial item is used as the nut, the part cost can be reduced.

  Further, since the nut is in contact with the stopper portion and the center plate is not in contact as a defined structure at one end of the stroke, the center plate is not required to have durability against contact. Therefore, a relatively lightweight resin can be used as the material of the center plate instead of a metal.

  Further, by providing a two-sided width detent between the nut and the casing, the inner peripheral edge of the diaphragm can be sufficiently detented to prevent malfunctions such as twisting in the diaphragm. .

  Further, by providing an axial flow path on the inner peripheral side of the return spring and on the outer peripheral portion of the poppet, the poppet holding the valve element can be increased in diameter and its strength can be increased. Accordingly, a relatively lightweight resin can be used as the poppet material instead of metal.

  Further, by providing a radial flow path on the spring receiving surface of the casing, the fluid can be circulated inside and outside even when the spring is compressed to the limit.

  Furthermore, by providing a convex portion on the bearing portion of the casing and correspondingly providing a concave portion on the adjustment screw, and providing an anti-rotation structure for the adjustment screw comprising a combination of the convex portion and the concave portion, the adjustment screw is attached to the casing. The rotation can be sufficiently prevented, and the adjustment accuracy of the spring load of the spring can be stabilized.

1 is an external perspective view of a pressure release valve according to an embodiment of the present invention. Vertical sectional view of the same pressure release valve Illustration of the internal structure of the same pressure release valve (A) is explanatory drawing of a spring and a spring receiving surface, (B) is explanatory drawing which shows the state by which the spring was compressed from the state of (A). DD main part enlarged sectional view in FIG. Longitudinal sectional view showing the state when the pressure release valve is forcibly opened The longitudinal cross-sectional view of the pressure relief valve which concerns on the other Example of this invention. EE sectional view in FIG. Sectional view of pressure release valve according to conventional example

The present invention includes the following embodiments.
(1) In order to satisfy the automatic valve opening function and the forced valve opening function, the conventional product has a large number of parts, there is a problem of cost, and there is a disadvantage that the size is increased.

(2) Configuration Therefore, in the present invention, in order to reduce the number of parts as much as possible and to make a small and inexpensive relief valve structure,
(2-1) A structure in which a fastening portion of the center plate and the hexagon nut is provided on the lower side of the diaphragm.
(2-2) Further, by installing a spring that biases the valve element and the valve seat at the low-pressure (no load) in the outer diameter portion of the poppet, it is possible to reduce the number of spring fixing parts and to make the poppet resin.
(2-3) Also, as the structure of the operating lever part, by providing a rotation stop on the inner diameter side of the adjusting screw and the return spring, the screw adjustment of the piston can be reliably performed even when the adjusting screw is in no load state (valve position adjustment) It has a structure that can
(2-4) Moreover, about the installation surface of a cover and a drainage spring, it becomes a shape which ensured the flow path for draining to an output side by providing a rib shape in a cover installation surface, even when a spring is close to a contact state. .

(3) Effect (3-1) A structure in which the fastening portion of the center plate and the hexagon nut is carried out at the lower part of the diaphragm (the caulking structure is conventionally the upper side).
・ Reduced size ・ Improves flexibility in setting the drainage spring ・ Reduces costs by improving the flexibility in setting the hexagon nut (because it can be set with a commercial product instead of a special size product)
(3-2) Structure in which the spring energizing the poppet is the outer diameter of the flow path (conventional flow path inner diameter structure)
・ Reduced number of parts (Internal springs require parts to fix)
-Since the inner diameter of the poppet can be made larger, it is more advantageous in terms of strength than conventional ones (thus making it possible to use a resin and reduce component costs)
(3-3) A structure in which the rotation of the adjustment screw is provided at the inner diameter part of the return spring. The accuracy is improved in the adjustment screw adjustment state by having a rotation stopper. This adjustment screw, piston, and return spring can be installed in the inside, and the structure becomes small (small in the axial direction). (3-4) The structure where the drainage spring installation seat surface of the cover is ribbed, and the cover installation seat By adding ribs to the surface, the flow path is secured even in a state close to the close contact of the drainage spring, and stable drainage is possible.

(4) Further, by providing a two-sided width detent between the nut and the casing, once assembled, the screw is not loosened. Conventionally, since an adhesive, caulking, or the like has been used for the screw fastening portion, the cost can be reduced in comparison with this.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an external perspective view of a pressure release valve according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view in the initial state. The pressure release valve according to this embodiment is configured as follows.

  That is, first, a casing 1 of the pressure relief valve is provided by combining a body 2 in the upper and lower half of the figure and a cover 3 in the upper half, and the casing 1 has a fluid inflow port 4 at its bottom position and a side surface. An outflow port 5 is provided at the position. Further, as shown in FIG. 2, in the casing 1, an inflow chamber (primary side pressure chamber) 6 that leads to the inflow port 4 and an outflow chamber (secondary side pressure chamber) 7 that leads to the outflow port 5 are formed. An annular diaphragm 21 is installed so as to partition, and a center plate 22 is disposed on the inner peripheral side of the diaphragm 21. The center plate 22 is an annular and cylindrical part, and an annular protrusion-shaped valve seat 23 is integrally provided at the end on the inflow chamber 6 side in the vertical direction of the figure, and flows out to the outer peripheral surface thereof. An annular hook-shaped spring retainer portion 24 located on the chamber 7 side is integrally provided. The diaphragm 21 has an outer peripheral edge (fixed end) sandwiched between the body 2 and the cover 3, and an inner peripheral edge (free end) of the diaphragm 21 is on the side of the spring retainer 24 and the inflow chamber 6. Are sandwiched between nuts 25 screwed onto the outer peripheral surface of the center plate 22. An annular protective plate 26 for preventing the diaphragm 21 from being scratched is interposed between the inner peripheral edge of the diaphragm 21 and the nut 25, but this plate 26 may be omitted. As the nut 25, as shown in the figure, since there is a sufficient space for installation, a commercially available hexagonal nut is appropriately selected and used.

  A poppet (first valve lift shaft) 27 is disposed on the inner peripheral side of the center plate 22 so as to be capable of stroke in the axial direction (the vertical direction in the figure, that is, the operating direction of the valve seat 23 and the valve body 28). The annular valve body 28 is held by the attachment screw 30 together with the valve body cover 29 at the end portion on the inflow chamber 6 side. The valve body 28 is arranged on the inflow chamber 6 side of the valve seat 23 and is arranged upward in the figure. Therefore, the valve body 28 and the valve seat 23 face each other in the axial direction, and are brought into contact with and separated from each other during operation. Opens and closes.

  The poppet 27 is held by the center plate 22 via a return spring (first return spring) 31. That is, as shown in the partial perspective view of FIG. 3, the poppet 27 is basically a cylindrical part having a constant diameter, and an outward hook-like spring engaging part 32 is integrally provided in the vicinity of the upper end part thereof. It has been. An inwardly hooked spring engaging portion 33 is provided on the inner peripheral surface of the center plate 22 and is located on the inflow chamber 6 side of the engaging portion 32, and a return spring is provided between the engaging portions 32, 33. Thus, the poppet 27 is held by the center plate 22 via the return spring 31. Reference numeral 27a denotes a screw hole into which the mounting screw 30 is screwed, 27b denotes a cavity for adjusting the weight, and 27c denotes a valve body pressing part.

  Further, an axial flow path 34 for guiding the fluid that has passed between the valve seat 23 and the valve body 28 when the valve is opened to the outflow chamber 7 is provided on the outer peripheral surface of the poppet 27 located on the inner peripheral side of the return spring 31. It has been. That is, the flow path 34 has a groove shape extending in the axial direction and a through hole shape continuously extending in the axial direction in the vicinity of the engaging portion 32, and an upper end portion thereof opens to the upper end surface 27 d of the poppet 27. ing. In this embodiment, the five flow paths 34 are provided in a uniform arrangement, but the number of the flow paths 34 is arbitrary.

  Returning to the description of FIG. 2, the outflow chamber 7 is provided with a spring (drainage spring) 35 that elastically biases a group of components such as the center plate 22 provided with the valve seat 23 toward the valve element 28. . The spring 35 is interposed between the spring retainer portion 24 provided on the center plate 22 and the casing 1 above the spring retainer portion 24, and includes a group of parts including the center plate 22, the inner peripheral edge of the diaphragm 21, the plate 26 and the nut 25. Is pressed downward in the figure. The inner surface of the inflow chamber 6 is provided with a stopper portion 8 that defines one end limit (stroke limit toward the inflow chamber 6 side) of the stroke of the parts group such as the center plate 22 by contacting the nut 25. Therefore, in the initial state, the stroke is stopped by the nut 25 coming into contact with the stopper portion 8. As shown in the figure, the stopper portion 8 has a plurality of protrusions on the circumference, but other stopper components may be arranged in the inflow chamber 6.

  Further, as shown in an enlarged view in FIG. 4A, on the receiving surface (receiving portion bottom surface) 9a of the annular recessed spring receiving portion 9 provided on the inner surface of the casing 1 to hold the upper end portion of the spring 35, A radial flow path 10 for guiding fluid from the inner peripheral side (right side in the figure) to the outer peripheral side (left side in the figure) of the spring 35 is provided in a part of the circumference. That is, as shown in FIG. 2A, when there is an interval c between the pitches of the coiled springs 35, the fluid passes through the interval c between the pitches and flows from the inner peripheral side to the outer peripheral side of the springs 35. However, if the spring 35 is compressed to the limit as shown in FIG. 5B and the pitch c is temporarily lost, the fluid cannot pass through the pitch c at this time. In view of this, the spring receiving surface 9a of the casing 1 is provided with a radial flow path 10 having a groove shape or a recess shape, whereby the spring 35 passes through this flow path 10 as indicated by an arrow in FIG. The fluid flows from the inner periphery side to the outer periphery side. In this embodiment, six channels 10 are provided in a uniform manner, that is, in a radial manner, but the number of the passages 10 is arbitrary.

  Returning to the description of FIG. 2 again, a piston (second valve shaft) 36 is arranged on the outflow chamber 7 side of the poppet 27, and this piston 36 is a cylindrical shape provided integrally with the casing 1. The bearing portion 11 is held so as to be rotatable and capable of axial stroke. The bearing 11 and the piston 36 are sealed with a sealing material 37 such as an O-ring. A small-diameter male screw portion 38 is integrally provided at the upper end portion of the piston 36, and an adjustment screw 39 is screwed into the male screw portion 38.

  The adjustment screw 39 is an annular component having a screw hole (female screw portion) 40 provided on the inner peripheral surface thereof, and is fitted into the bearing hole portion 12 provided on the outer surface of the casing 1, so that the axial stroke with respect to the casing 1 is achieved. Although possible, it is prevented from rotating relative to the casing 1 so as not to rotate. As shown in FIG. 5, as the structure of the rotation stopper, a convex part 13 on the circumference is provided at the upper end of the bearing part 11 in the casing 1 upward, that is, toward the adjustment screw 39. The adjustment screw 39 is provided with a part of the concave portion 41 on the circumference, and the adjustment screw 39 is prevented from rotating with respect to the casing 1 by the engagement of the convex portion 13 and the concave portion 41. In this embodiment, two sets of anti-rotation structures composed of combinations of the convex portions 13 and the concave portions 41 are provided in a uniform manner, but the number of formations is arbitrary. A second return spring 42 is interposed between the bearing portion 11 and the adjustment screw 39.

  Further, the upper end portion of the adjustment screw 39 protrudes outside the casing 1, and a lever 43 for pressing the adjustment screw 39 is provided outside the casing 1. The lever 43 is manually operated, with the horizontal center axis 43b shown in FIG. 1 or 5 as the center, and from the steady position (side-down state) shown in FIG. 1 or FIG. 6), the adjusting screw 39 is pressed downward when the operating position shown in FIG. 6 is reached, and the return springs 31 and 42 are elastic. Against this, the parts group consisting of the piston 36, poppet 27, mounting screw 30, valve body cover 29 and valve body 28 is displaced downward, and the valve body 28 is separated from the valve seat 23 to forcibly open the valve. On the other hand, when the operating position shown in FIG. 6 is returned to the steady position shown in FIG. 2, the parts of the piston 36, poppet 27, mounting screw 30, valve body cover 29, and valve body 28 are formed by the elasticity of the return springs 31 and 42. The valve returns to its original position and the valve closes.

  The lever 43 has a lever main body 43a, and a pair of central shafts (rotating shafts) 43b are integrally provided on the left and right side surfaces of the lever main body 43a. The pair of central shafts 43b is press-fitted into a pair of notched shaft holes 14 provided corresponding to the head of the casing 1, that is, a structure that is assembled into the shaft hole 14 of the casing 1 by one-touch press-fitting by a snap-fit structure. ing.

  Further, the lever 43 is provided with a through-hole-like through portion 43c for inserting a jig such as a screwdriver in the vertical direction at the normal position, and below the screw hole 40 of the adjustment screw 39 and the piston 36. A male screw portion 38 is disposed. Therefore, when the lever 43 is in the steady position, it is possible to rotate the male screw portion 38 by inserting a jig such as a screwdriver from the through portion 43 c, and thereby the screwing amount of the male screw portion 38 with respect to the adjustment screw 39. Thus, the initial load of the spring 35 can be adjusted.

  In the component group, the body 2, the cover 3, the center plate 22, the poppet 27, the piston 36, the adjusting screw 39, and the lever 43 are made of resin.

  Next, the operation of the pressure release valve will be described.

<Initial state and valve closed>
FIG. 2 shows the initial state of the pressure release valve as described above. In this initial state, the nut 25 is urged by the spring 35 and abuts against the stopper portion 8, and the center plate 22 and the diaphragm 21 are in contact with each other. A group of parts including the peripheral portion, the plate 26 and the nut 25 is located at one end of the stroke. The valve body 28 is urged by the first return spring 31 and comes into contact with the valve seat 23, so that the valve is closed. In this state, the initial load of the spring 35 can be adjusted. That is, when the male thread portion 38 is rotated using a jig such as a screwdriver to retract the piston 36 upward, the piston 36 An initial clearance (not shown) for retraction is set between the poppet 27 and the poppet 27. When the open valve is connected to a pipe (not shown) and a low-pressure fluid flows from the inflow port 4, the fluid pressure (primary side pressure) is changed to the diaphragm 21, the nut 25, the center plate 22, the valve body cover 29, and When acting on the mounting screw 30, these parts move together with the poppet 27 and the first return spring 31 while moving the spring 35 toward the outflow chamber 7, and when the initial clearance disappears and the poppet 27 comes into contact with the piston 36. The movement stops. Since the fluid pressure (primary pressure) is low (steady state), the valve remains closed, so the pressure has not yet been released.

<Automatic valve opening>
When the fluid pressure (primary side pressure) increases and exceeds a certain value in the above valve closed state, the component group consisting of the center plate 22, the inner peripheral edge of the diaphragm 21, the plate 26 and the nut 25 becomes the spring 35 and the first return spring. It moves toward the outflow chamber 7 while compressing 31. Since the valve body 28 cannot move because the poppet 27 is in contact with the piston 36, the valve seat 23 moves away from the valve body 28 and opens. Accordingly, the pressure is released. When the fluid pressure (primary side pressure) falls below a certain value, the component group consisting of the center plate 22, the inner peripheral edge of the diaphragm 21, the plate 26 and the nut 25 is brought into the inflow chamber by the elasticity of the spring 35 and the first return spring 31. The valve seat 23 comes into contact with the valve body 28 and closes. Accordingly, the pressure release ends. Note that the magnitude of the valve opening pressure at this time is adjusted by inserting a jig such as a screwdriver into the penetrating portion 43c provided in the lever 43 as described above, and adjusting the screwing amount of the male screw portion 38 with respect to the adjusting screw 39. Therefore, it can be adjusted in advance.

<When forced open>
Further, when the pressure release valve is forcibly opened as required, when the lever 43 is manually rotated as shown in FIG. 6, the lever 43 presses the adjustment screw 39, and the adjustment screw 39, piston 36, poppet 27, the mounting screw 30, the valve body cover 29, and the valve body 28 move toward the inflow chamber 6 while compressing the first and second return springs 31 and 42, and the valve body 28 is separated from the valve seat 23. Therefore, the valve is opened and the pressure is released. When the lever 43 is returned to the steady position after being opened, the parts including the adjusting screw 39, the piston 36, the poppet 27, the mounting screw 30, the valve body cover 29, and the valve body 28 by the elasticity of the first and second return springs 31 and 42. The group returns to the outflow chamber 7 and the valve element 28 comes into contact with the valve seat 23, so that the valve is closed and the pressure release ends.

  The pressure release valve operates as described above, and is characterized by the following operational effects as an invention.

  In other words, the pressure release valve having the above-described configuration includes the casing 1 provided with the fluid inflow port 4 and the outflow port 5, the inflow chamber 6 that communicates the internal space of the casing 1 with the inflow port 4, and the outflow chamber 7 that communicates with the outflow port 5. A diaphragm 21 arranged to partition, a center plate 22 fixed to the inner peripheral edge of the diaphragm 21 and provided with a valve seat 23 at the end on the inflow chamber 6 side, and disposed on the inflow chamber 6 side of the valve seat 23 And a valve body 28 that can be brought into and out of contact with the valve seat 23, a spring 35 that elastically biases the center plate 22 provided with the valve seat 23 toward the valve body 28, and an inner peripheral side of the center plate 22 The poppet 27 is disposed so as to be displaceable in the axial direction and holds the valve element 28, and the bearing 11 provided in the casing 1 and disposed on the outflow chamber 7 side of the poppet 27. The piston 36 is rotatably held in the circumferential direction and is displaceable in the axial direction, a male screw portion 38 provided at an end of the piston 36 opposite to the poppet 27, and a male screw portion 38. An adjustment screw 39 that is axially displaceable with respect to the casing 1 and an adjustment screw 39 that is disposed outside the casing 1 and is swayed. When the swaying operation is performed, the piston 36, the poppet 27, and the valve body 28. And a forced opening valve lever 43 for separating the valve body 28 from the valve seat 23 by displacing a group of parts in the axial direction, and is arranged in the outflow chamber 7 on the outer periphery of the center plate 22 and is a spring. A spring retainer portion 24 that holds one end of 35 is integrally provided, and a nut 25 is screwed onto the outer peripheral portion of the center plate 22 in the inflow chamber 6, Ring retainer 24 and the nut 25 is an inner peripheral end portion sandwich the retention structures of the diaphragm 21. Therefore, in the pressure release valve having the automatic valve opening function and the forced valve opening function, the crimping portion is omitted from the center plate 22 in comparison with the conventional technique, and the spring retainer portion 24 is disposed at the position where the crimping portion exists. Therefore, it is possible to install a small-diameter spring 35 along with this. Therefore, the degree of freedom of the set size of the spring 35 can be increased, and the nut 25 is disposed in a part of the inflow chamber 6 which was a conventional dead space, so that this space can be used effectively. . Therefore, from these facts, it is possible to reduce the size of the valve. Further, by using a commercially available nut 25, the part cost can be reduced.

  Further, in the pressure release valve having the above configuration, when the center plate 22 is urged by the spring 35 and strokes toward the valve body 28, the nut 25 comes into contact with the stopper portion 8 set inside the casing 1. A structure is provided in which one end of the stroke is defined. Therefore, the nut 25 is in contact with the stopper portion 8 and the center plate 22 is not in contact as a defined structure at one end of the stroke, so that the center plate 22 is not required to have durability against contact. Therefore, a relatively light resin can be used as the material of the center plate 22 instead of a metal.

  In the pressure release valve having the above-described configuration, the return spring 31 is interposed between the center plate 22 and the poppet 27 on the inner peripheral side of the center plate 22. An axial flow path 34 for guiding the fluid that has passed between the valve seat 23 and the valve body 28 to the outflow chamber 7 is provided in a part of the circumference of the outer peripheral portion. Therefore, the diameter of the poppet 27 can be increased to increase its strength, and a relatively lightweight resin can be used as the material of the poppet 27 instead of a metal.

  In the pressure release valve having the above-described configuration, an annular spring receiving surface 9a for holding the other end of the spring 35 is provided on the inner surface of the casing 1, and the inner portion of the spring 35 is formed on a part of the circumference of the spring receiving surface 9a. A radial flow path 10 is provided for guiding fluid from the circumferential side to the outer circumferential side. Therefore, even if the spring 35 is compressed to the limit, the fluid can be circulated inside and outside.

  Further, in the pressure release valve having the above-described configuration, the adjustment screw 39 is prevented from rotating with respect to the casing 1, and for this reason, the bearing portion 11 in the casing 1 is provided with a convex portion 13 on the circumference toward the adjustment screw 39. Correspondingly, a part of the recess 41 on the circumference is provided in the adjustment screw 39, and the rotation prevention structure of the adjustment screw 39 with respect to the casing 1 is provided by the engagement of the protrusion 13 and the recess 41. Therefore, the adjustment screw 39 can be sufficiently prevented from rotating with respect to the casing 1, and the adjustment accuracy of the spring load of the spring 35 can be stabilized.

  As another structure, there is a concern that the diaphragm 21 may be twisted as described above. However, in the pressure release valve, the nut 25 is disposed in the inflow chamber 6 of the casing 1. It is conceivable that a hexagonal nut is used (a commercially available product may be used as described above), and the inner peripheral edge of the diaphragm 21 is prevented from rotating using this hexagonal nut.

  That is, as shown in FIG. 7 and FIG. 8, two surfaces 25a and 25d that are 180-degree symmetric positions among the planes 25a to 25f of the outer peripheral six surfaces provided in the hexagon nut 25 are used. Two-sided inner peripheral planes 1a and 1d having the same width are provided on the inner surface of the inflow chamber 6 of the casing 1, and these are engaged with each other to set a detent of the two-sided width structure. In this manner, the nut 25, the center plate 22, the inner peripheral edge portion of the diaphragm 21 and the plate 26 are prevented from rotating with respect to the casing 1, so that the diaphragm 21 is prevented from being twisted in the circumferential direction. Can be suppressed.

DESCRIPTION OF SYMBOLS 1 Casing 1a, 1d Inner peripheral plane 2 Body 3 Cover 4 Inflow port 5 Outflow port 6 Inflow chamber 7 Outflow chamber 8 Stopper part 9 Spring receiving part 9a Spring receiving surface 10 Radial flow path 11 Bearing part 12 Bearing hole part 13 Convex part 14 Shaft hole 21 Diaphragm 22 Center plate 23 Valve seat 24 Spring retainer portion 25 Nut 25a to 25f Peripheral plane 26 Plate 27 Poppet 28 Valve body 29 Valve body cover 30 Mounting screw 31 Return spring 32, 33 Spring engagement portion 34 Axial flow Path 35 Spring 36 Piston 37 Sealing material 38 Male thread part 39 Adjustment screw 40 Screw hole 41 Recess 42 Second return spring 43 Lever

Claims (6)

A casing provided with an inflow port and an outflow port for fluid, an annular diaphragm arranged to partition an internal space of the casing into an inflow chamber that communicates with the inflow port and an outflow chamber that communicates with the outflow port; and the diaphragm An annular protrusion-shaped valve seat is integrally provided at the end on the inflow chamber side, and an annular flange-like spring retainer portion located on the outflow chamber side is integrally provided on the outer peripheral surface of the valve seat. An annular and cylindrical center plate, a poppet disposed on the inner peripheral side of the center plate so as to be axially displaceable, and held at an end portion on the inflow chamber side of the poppet and disposed opposite to the valve seat rotation in the circumferential direction by a bearing portion provided on the casing and detachably and to the valve body and the valve seat, while being arranged in the outflow chamber side of the poppet with the Noh and pistons displaceably held in the axial direction, said interposed between the spring retainer and said casing, a spring for elastically urging said center plate provided with the valve seat to the valve body When, from said poppet in the piston and the male threaded portion provided at the opposite end, the adjustment screw that is capable axial displacement relative to the casing with screwed to the male screw portion, of the casing Forced valve opening that is arranged outside and is operated to swing, and when the swing operation is performed, the adjustment screw, piston, poppet and valve body are displaced in one axial direction to separate the valve body from the valve seat and a use lever,
A nut is screwed into the outer peripheral portion of the center plate in the inflow chamber, and the inner peripheral end portion of the diaphragm is sandwiched and held by the spring retainer portion and the nut of the center plate. Pressure relief valve. The pressure relief valve of claim 1,
A structure is provided in which one end of the stroke is defined by the nut abutting against a stopper set inside the casing when the center plate is urged by the spring and strokes toward the valve body. A pressure relief valve. The pressure relief valve according to claim 1 or 2,
The nut is a hexagonal nut, and a two-sided inner peripheral plane having a width equivalent to the width of two sides at a target position of 180 degrees among the six outer sides of the hexagonal nut is provided on the inner surface of the casing. pressure relief valve, wherein a detent two surface width structures by engaging with each other are provided between the nut and the casing. The pressure relief valve according to claim 1, 2 or 3,
The poppet is integrally provided with an outward hook-like spring engaging portion at the piston side end, and is located on the inflow chamber side of the engaging portion on the inner peripheral surface of the center plate. Spring engagement portions are provided, and a return spring is interposed between the two engagement portions, and passes between the valve seat and the valve body on the inner peripheral side of the return spring and on the outer peripheral portion of the poppet. The pressure relief valve is characterized in that an axial flow path for guiding the fluid to the outflow chamber is provided in the form of a groove extending in the axial direction or a through hole extending in the axial direction . The pressure relief valve according to claim 1, 2 or 3,
An annular spring receiving surface for holding the other end of the spring is provided on the inner surface of the casing, and a radial flow path for guiding fluid from the inner peripheral side to the outer peripheral side of the spring is formed in a concave shape on the spring receiving surface. A pressure relief valve characterized by being provided. The pressure relief valve according to claim 1, 2 or 3,
A second return spring is provided between the bearing portion and the adjustment screw in the casing, and the adjustment screw is prevented from rotating with respect to the casing. For this reason, the bearing portion in the casing faces the adjustment screw. A convex part on the circumference is provided, and a part on the circumference is provided in the concave part correspondingly to the adjusting screw, and the convex part and the concave part are engaged with each other to engage the adjusting screw with respect to the casing. A pressure relief valve, characterized in that a detent structure is provided.

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