JP4147211B2 - Pressure regulating valve - Google Patents

Description

  The present invention relates to a pressure regulating valve (relief valve), and more particularly, is used in a piping system for fluids such as cleaning liquid, chemical liquid, and corrosive liquid in semiconductor manufacturing equipment, medical equipment, food manufacturing equipment, chemical processing equipment, and the like. The present invention relates to a pressure regulating valve.

  The pressure regulating valve includes a communication port between the supply-side channel and the discharge-side channel, a valve box having a valve body that opens and closes the valve, and a biasing unit that biases the valve body so that the communication port is closed. When the pressure of the supply side flow path exceeds a predetermined value, the valve body is opened and moved against the urging force of the urging means, the communication port is opened, and the supply side flow When the pressure in the passage is below a predetermined value, the communication port is kept closed, and is used as a pump discharge pressure regulation, circuit pressure control and safety valve. For example, used as a relief valve or pressure reducing valve that keeps the pressure in the circuit below the set value, or as a sequence valve or unload valve that automatically switches the circuit when the pressure in the circuit reaches the set value It is a valve.

  Conventionally, as a pressure regulating valve used in a piping system, as disclosed in Patent Document 1, a spring box (lid box) and a valve box are provided in an annular space where a supply side flow path and a discharge side flow path are connected. A diaphragm fixed between them is arranged, and this diaphragm is pressed against the valve seat by a relief spring via a spring receiver, that is, a diaphragm type valve. In the pressure regulating valve having such a configuration, when the pressure of the fluid existing in the supply side flow path becomes larger than the urging force acting on the diaphragm by the relief spring, the spring receiver is pushed back via the diaphragm, and the diaphragm and the valve seat The fluid flows from the gap generated between the two to the discharge side flow path. That is, the upper limit of the circuit pressure is adjusted by the urging force of the relief spring.

According to the pressure regulating valve having the above-described structure, an excellent advantage that liquid leakage does not occur first can be obtained by opening and closing the valve seat using the diaphragm. However, since the diaphragm has a large diameter and a large pressure receiving area with respect to the size of the entire valve, there is a disadvantage that the diaphragm is easily influenced by the fluid pressure of the supply side flow path and easily vibrates. When the pump that supplies the fluid has pulsation, the vibration tends to become remarkable, and the operation tends to become unstable. If pressure accuracy varies in pressure control, the environmental load may increase. Further, since the diaphragm is made of a flexible thin film material such as a synthetic resin sheet, it may be damaged when excessive pressure is applied.
JP-A-6-94147

  In view of the above circumstances, the present invention is less susceptible to fluid pressure fluctuations, can stably perform pressure adjustment operations, and does not cause a possibility of being damaged even if a slight excessive pressure is applied. The object is to provide an improved pressure regulating valve.

The invention according to claim 1 is such that the communication port 3A between the supply-side flow path 3 and the discharge-side flow path 4 and the valve box 1 having the valve body 5 for opening and closing the same are closed. The lid box 2 having the urging means 7 for urging the valve body 5 is assembled. When the pressure of the supply side flow path 3 exceeds a predetermined value, the urging force by the urging means 7 is resisted. A pressure regulating valve configured to maintain the closed state of the communication port 3A when the valve body 5 is opened and moved to open the communication port 3A and the pressure of the supply-side flow path 3 is not more than a predetermined value. In
The valve body 5 can be freely opened and closed by the bottom surface 10a at the front end , and the valve portion 10 to which the urging force is applied is formed integrally with the valve portion 10 in an airtight manner. And the bellows 11 whose other end is fixed in an airtight manner to the valve box 1 ,
The height H of the peripheral surface 10b rising from the bottom surface 8c of the valve portion 10 is set to be larger than the diameter of the opening edge 4a of the discharge-side flow path 4 formed to face the peripheral surface 10b. And

  According to a second aspect of the present invention, in the pressure regulating valve according to the first aspect, the lid box 2 is formed with an air hole 30 that allows the outside of the lid box 2 to communicate with the internal space 22 in which the biasing means 7 is accommodated. It is characterized by being.

  The invention according to claim 3 is the pressure regulating valve according to claim 1 or 2, wherein the moving direction of the valve body 5 for opening and closing the communication port 3A and the direction of the supply side flow path 3 are the same. It is set and it is comprised so that the direction of the said discharge side flow path 4 may orthogonally cross with respect to this direction.

  According to a fourth aspect of the present invention, in the pressure regulating valve according to any one of the first to third aspects, the biasing means 7 is a coil spring 26 that elastically biases the valve portion 10 via a rod-shaped member 25a. The bellows 11 has an inner peripheral portion guided by the rod-like member 25a and an outer peripheral portion guided by the peripheral wall 8a of the recessed space 8 for accommodating the valve body 5 of the valve box 1. It is characterized by being formed in a bellows cylindrical shape.

  The invention according to claim 5 is the pressure regulating valve according to claim 4, wherein the discharge-side flow path 4 is configured to open to the peripheral wall 8 a of the recessed space 8, and the distal end periphery of the valve portion 10. Is chamfered.

  The invention according to claim 6 is the pressure regulating valve according to any one of claims 1 to 5, wherein the valve portion 10 and the bellows 11 are integrally formed of a synthetic resin material, and the lid box side end The portion is formed in a flange portion 12 that is sandwiched between the valve box 1 and the lid box 2.

  The invention according to claim 7 is the pressure regulating valve according to claim 6, wherein the synthetic resin material is a fluororesin.

  According to the first aspect of the invention, since the movable part is a bellows, the size of the valve body in the plan view direction can be made compact, and it is impossible even if the movement of the valve portion is large while the pressure receiving area is small. Compared to the diaphragm type, there is an advantage that the valve can withstand high pressure and can be made compact. As a result, an improved pressure control valve is provided that is less susceptible to the effects of fluid pressure fluctuations, enables stable pressure adjustment operations, and does not cause damage even if a slight excessive pressure is applied. can do. In this case, as in claim 4, if the inner and outer sides of the bellows are guided by the outer peripheral portion of the rod-shaped member that is a member for transmitting the biasing force of the biasing means and the peripheral wall of the recessed space, In addition, it is possible to provide a pressure regulating valve which can smoothly move up and down of the bellows during the valve closing operation without being tilted or deformed, has a good opening / closing operation, and has a good response.

  According to invention of Claim 2, there exist the following effects. That is, when the fluid pressure in the supply-side flow path increases and the valve body is lifted and moved to open and move, the internal space of the lid box partitioned by the bellows or the like is compressed. Since the valve body is almost closed, the compression reaction force acts when the valve body opens and moves, making it difficult for the valve body to open and moving, adversely affecting the responsiveness, and also due to fluid pressure fluctuations The risk of hunting increases. Therefore, as described in claim 2, if an air hole is provided to communicate the internal space with the outside of the lid box, the above-described adverse effect due to the compression of the air in the internal space does not occur. As a result, the body can move up quickly and the valve opening operation is performed instantaneously, so that the responsiveness is excellent and hunting hardly occurs.

  According to the invention of claim 3, the moving direction of the valve body for opening and closing the communication port and the direction of the supply side flow path are set to be the same, and the direction of the discharge side flow path is orthogonal to this direction. Since it is configured in a state, that is, an L-shaped flow path, the flow of the fluid when the valve body is opened and moved by the pressure increase only needs to be changed once in the direction of 90 degrees. The pressure loss at the time of passing can be suppressed small, and the pressure regulating valve that can contribute to suppressing the pressure loss of the piping system can be provided.

  According to the invention of claim 5, even if the opening edge of the discharge-side flow channel opening in the peripheral wall of the valve chamber is a sharp corner (pin corner) due to the chamfering process of the peripheral edge of the valve portion, Since the opening edge and the valve portion slide relative to each other, inconvenience that the tip edge of the valve portion is damaged or scraped can be prevented in advance, and the valve portion can be opened and closed smoothly and smoothly. It will be a thing.

  According to the invention of claim 6, since the valve portion and the bellows are integrated, and the flange portion is formed integrally with the bellows, the valve body using the bellows is realized by the integral structure of the valve body having the bellows. There is an advantage that the function of partitioning the fluid-existing side and the fluid non-existing side in an airtight manner can be realized with almost perfect airtightness and durability.

  According to the invention of claim 7, since the valve body, which is the most important part and is a movable member, is formed of a fluororesin, it has excellent chemical resistance, resistance to the external atmosphere, and high temperature and high pressure. A pressure regulating valve that can withstand is obtained.

  Embodiments of a pressure regulating valve according to the present invention will be described below with reference to the drawings. 1 and 2 are a front view and a bottom view of the pressure regulating valve, FIG. 3 is a sectional view showing the structure of the pressure regulating valve, FIG. 4 is a sectional view showing a valve opening state, and FIG. 5 is a sectional view of a single valve box. 6 is a detailed view of a portion A in FIG. 5, FIG. 7 is a cross-sectional view showing the structure of the pipe joint portion, FIG. 8 is a front view of a partially cutout valve body, and FIG. 9 is a detailed view of the bellows portion in FIG. It is.

  The pressure regulating valve A is made of a fluororesin (PTFE or the like) having a supply side flow path 3, a discharge side flow path 4, these communication ports 3 </ b> A, and a valve body 5 as shown in FIGS. 1 to 4. The valve box 1 and a lid box 2 made of a fluororesin (PTFE or the like) having a pressure (relief pressure) adjusting mechanism 6 and an urging means 7 are assembled so as to be screwed together. In this pressure regulating valve, the moving direction of the valve body 5 for opening and closing the communication port 3A and the direction of the supply side flow path 3 are set to the same valve axis P, and the adjusting mechanism 6 and the urging means 7 Is configured with its valve axis P as the center. When the fluid pressure in the supply side flow path 3 exceeds a predetermined value, the pressure regulating valve A opens and moves the valve body 5 against the urging force of the urging means 7 to open the communication port 3A. When the fluid in the passage 3 flows into the discharge side passage 4 and the fluid pressure in the supply side passage 3 is equal to or less than a predetermined value, the urging force by the urging means 3 is greater than the fluid pressure, and the communication port by the valve body 5 It functions as a relief valve that maintains the closed state of 3A.

  As shown in FIGS. 3 to 5, the rectangular columnar valve box 1 has an upper surface 1 </ b> A that opens to the upper surface 1 </ b> A, a cylindrical valve chamber 8 centered on the valve axis P, and an upper portion that extends below the valve chamber 8. A tubular supply-side flow path 3 centering on the valve axis P in the downward direction and a lateral discharge-side flow path 4 opening in the lower end portion of the peripheral wall 8a of the valve chamber 8 are formed, and A male screw portion 9 is formed on the outer periphery. The bottom surface 8c of the valve chamber 8 is a portion that functions as a valve seat with excellent surface accuracy, and the communication port 3A is a location where the supply-side flow path 3 opens into the valve seat 8c. The tube center X of the discharge side flow path 4 is orthogonal to the valve center P, so that the flow path of the fluid in the valve box 1 is such that the direction of the discharge side flow path 4 is relative to the vertical supply side flow path 3. It is formed in a substantially L-shaped path that is horizontally oriented (left-right orientation).

  On the center side of the upper surface 1A of the valve box 1, as shown in FIGS. 5 and 6, a highly precise finished seal surface 1a, which is a surface that comes into contact with the flange portion 12 of the valve body 5, is formed from the surrounding portion. Is also formed as a slightly lowered surface. A ring-shaped seal lip 19 having a wedge-shaped cross section is formed in the middle (center) portion in the radial direction of the seal surface 1a. The peripheral edge 8b of the upper end opening of the valve chamber 8 has a chamfered shape so as to be an inclined surface, and the communication port 3A has a chamfered shape. Further, as shown in FIG. 1, an arrow display B indicating the flow from the in-side supply side flow path 3 to the out-side discharge side flow path 4 when the valve is opened is provided on the front surface of the valve box 1. Yes.

  A pipe joint device (pipe joint structure) T for connecting and connecting a fluid transfer tube 41 made of synthetic resin such as fluororesin in a sealed state is provided at the outlet portion of each flow path 3, 4 in the valve box 1. A joint B is formed. For reference, the structures of the pipe joint device T and the joint part B having these known structures will be described using the discharge side flow path 4.

  As shown in FIGS. 1 to 5 and FIG. 7, the pipe joint device T includes a receiving portion 58 that receives the end portion of the tube 41 and three sealing surfaces 50 to 52 provided in the receiving portion 58. An union nut 56 made of a fluororesin such as PFA, which can be externally fitted and screwed to an end of the supply / exhaust port 55 in a state of being externally fitted to the end of the tube 41, and a union The tube 41 is pressed from the outside by tightening the nut 56 to the supply / discharge port 55 by screwing, and the end portion of the tube 41 and the sealing surfaces 50 to 52 of the supply / discharge port 55 are brought into close contact with each other by this pressing action. It is comprised from the three seal parts S1-S3 formed. The joint part B is composed of portions excluding the tube 41, that is, a supply / discharge port 55, an inner ring 65, and a union nut 56.

  The supply / discharge port 55 is a cylindrical portion protruding from the valve box 1, and a main body cylinder portion 57 having a receiving portion 58, which is a portion into which the tube 41 is fitted, on the inner diameter side thereof, It is formed in a substantially double cylinder composed of a small protruding auxiliary cylinder part 59. Then, as shown in FIG. 7, first to third seal surfaces 50 to 52 are provided inside the receiving portion 58 of the supply / discharge port 55. The first seal surface 50 is a front end surface of the auxiliary cylinder portion 59 located inward from the inlet of the receiving port 58 of the supply / discharge port 55 and intersects the tube center X of the supply / discharge port 55. That is, it is constituted by a tapered surface that gradually increases in diameter toward the outside in the tube center X direction. The second seal surface 51 is formed at the inlet of the receiving port 58 by a tapered surface that intersects the tube center X, that is, gradually increases in diameter toward the outside in the tube center X direction. The third seal surface 52 is radially outward from the first seal surface 50 in the groove between the main body cylinder portion 57 and the auxiliary cylinder portion 59, that is, in the back of the receiving portion 58 of the supply / discharge port 55. And an annular groove 53 formed in parallel with the tube center X. A male screw 54 is formed on the outer periphery of the receiving port 58 of the supply / discharge port 55.

  On the other hand, an inner ring 65 made of a fluororesin such as PFA is press-fitted into the distal end portion of the tube 41. As shown in FIG. 7, the inner ring 65 is press-fitted into the end portion of the tube 41, and a press-fit portion 66 having an abacus-shaped cross section that expands the end portion into a cross-sectional mountain shape, and is connected to the press-fit portion 66. It is formed in a sleeve shape having a protruding portion 69 that is provided and protrudes from an end portion of the tube 41. The press-fitting portion 66 having a mountain-shaped cross section has an end portion of the tube 41 sandwiched in an inclined state between an outwardly tapered surface 68 on one slope portion and a second seal surface 51 on the other slope portion. An inwardly tapered surface 60 that forms the seal portion S2 is formed. At the tip of the projecting portion 69, the projecting end surface 62, which is a tapered surface that is in close contact with the first seal surface 50 to form the first seal portion S1, and the annular groove 53 are fitted into the third seal portion. A cylindrical portion 64 that forms S3 is formed. The inner diameter of the inner ring 65 is set to be the same as or substantially the same as the inner diameter of the tube 41 so that the fluid can flow smoothly without stagnation.

  As shown in FIG. 7, the union nut 56 is formed with a female screw 56a threadedly engaged with the male screw 54 of the supply / exhaust port 55 on its inner periphery, and an annular flange 61 is projected inwardly at one end. Further, an acute angle or right angle pressing edge 63 is provided at the axially inner end of the inner peripheral surface of the annular flange 61. Then, the end portion of the tube 41 into which the inner ring 65 is press-fitted is inserted into the receiving portion 58 of the supply / exhaust port 55, and the female screw 56a of the union nut 56 that is loosely fitted in advance to the outer periphery of the end portion of the tube 41 is supplied. Screw into the male thread 54 of the exhaust port 55 and tighten. A gauge ring 49 made of ethylene tetrafluoroethylene (ethylene tetrafluoroethylene polymer: ETFE) is fitted on the base side portion of the supply / discharge port 55 so as to define the tightening limit of the union nut 56. .

  Along with this tightening, the pressing edge portion 63 of the union nut 56 abuts against the enlarged diameter root portion of the enlarged diameter portion 67 of the tube 41 to press the inner ring 65 from the axial direction. As a result, as shown in FIG. 7, the protruding end surface 62 of the inner ring 65 is pressed against the first seal surface 50 of the supply / discharge port 55 to form the first seal portion S1, and the inner ring 65 The end portion of the tube 41 is sandwiched between the direction taper surface 60 and the second seal surface 51 of the supply / discharge port 55 to form the second seal portion S2, and the cylindrical portion 64 of the inner ring 65 is further formed. Is pressed into the annular groove 53 to form the third seal portion S3. These first to third seal portions S1 to S3 exhibit a highly reliable seal function.

As shown in FIGS. 3, 4, 8, and 9, the valve body 5 is in contact with the valve seat 8 c by the bottom surface 10 a at the tip to freely open and close the communication port 3 </ b> A, and the urging force by the urging means 7. And a bellows 11 having a lower end integrated with the valve portion 10 and fixed at one end in an airtight manner, and an upper end fixed at the valve box 1 in an airtight manner. ing. The upper end of the bellows 11 is formed in a flange portion 12 that is sandwiched between the upper and lower sides of the lid box 2 and the valve box 1 by tightening the lid box 2 and the valve box 1. It is a single part made of a fluororesin (PTFE or the like) having a bellows 11 and a flange portion 12 and having a cylindrical hole 20 for fitting a pressing rod (described later) 25b at the center. Is formed into a thing. The function of partitioning the valve chamber 8 in an airtight manner by using the bellows 11 is almost completely airtight, for example, compared to means for connecting the separate members in an airtight manner by the integrated structure of the valve body 5. Moreover, it can be realized with durability.

The valve portion 10 is a cylindrical portion having a circular bottom surface 10a that has been surface-finished with high precision so as to come into surface contact with the valve seat 8c, and a peripheral edge 10f that is a corner portion at the lower end of the bottom surface 10a is chamfered and inclined. Formed on the surface. By this chamfering process, the opening edge 4a of the discharge-side flow path 4 that opens to the peripheral wall 8a of the valve chamber 8 is opposed to the peripheral surface 10b rising from the bottom surface 10a of the valve portion 10 to a sharp corner (so-called pin corner). Even if it becomes, it has the structure where the inconvenience that the front edge of the valve part 10 is damaged or scraped off by the opening edge 4a is prevented beforehand. The height H of the peripheral surface 10b rising from the bottom surface 10a of the valve portion 10 is a value larger than the diameter of the opening edge 4a formed facing the peripheral surface 10b of the valve portion 10, and when the valve body 5 is expanded or contracted ( When the upper edge of the opening edge 4a and the valve portion 10 are in contact with each other, the condition of the opening edge 4a is not changed. It is set as the structure by which the catch by separation does not arise.

  In addition, a circumferential groove 14 for planting a fluororubber O-ring 13 is formed on the bottom surface 10a, and this circumferential groove 14 has a width at the lower end outlet in order to prevent the O-ring 13 from dropping downward. It is formed in the cross-sectional shape which becomes narrow and narrows. The bottom surface 10a of the valve body 10 and the valve seat 8c are in surface contact with each other, and an O-ring 13 is interposed between the two so that the communication port 3A is completely sealed in the closed state. Realizing performance. The valve body 5 includes a valve body 10, a bellows 11, and a flange portion 12, which are separate parts. The upper end portion of the bellows 11 is connected to the flange portion 12 in an airtight manner, and the lower end portion of the bellows 11 is A structure in which the valve body 10 is connected in an airtight manner may be used.

  As shown in FIGS. 8 and 9, the bellows 11 includes upper and lower hook-shaped portions 15 and 16 arranged in a plurality of upper and lower stages, and a mountain fold portion 17 on the outer peripheral side that alternately connects the hook-shaped portions 15 and 16. It is formed in a bellows-like shape composed of a valley fold portion 18 on the inner peripheral side, and all the mountain fold portions 17 and valleys are formed in a state where all the flange-like portions 15 and 16 are horizontal in design. The folded portion 18 is set to be a vertical peripheral wall. The inner peripheral surface 17a of the mountain fold portion 17 is formed on a curved surface and an inclined edge 17b in which the upper and lower corners of the outer peripheral surface are cut obliquely. The outer peripheral surface 18b of the valley fold portion 18 is formed on a curved surface and an inclined edge 18a in which the upper and lower corners of the inner peripheral surface are obliquely cut.

  The flange portion 12 includes a small-diameter portion 12A having the same outer diameter as that of the mountain fold portion 17, and an outer peripheral flange 12B sandwiched between the valve box 1 and the lid box 2, and the small-diameter portion 12A. The uppermost end valley fold 18 is formed in a continuous state at the inner peripheral side end portion. The ring-shaped bottom surface 12b of the outer peripheral flange 12B that is in contact with a sealing surface (described later) 1a on the upper surface of the valve box 1 is subjected to a highly accurate finishing process so as to obtain high sealing performance. In addition, the outer diameter of the valve part 10 is also formed in the same dimension as the outer diameter of the mountain fold part 17.

  The valve body 5 having the above structure is set to a dimension whose outer diameter is slightly smaller than the inner diameter of the valve chamber 8, and the inner diameter, that is, the diameter of the cylindrical hole 20 is a pressure bar (described later) 25 b. The dimension is set to a value slightly larger than the outer diameter. As a result, the valve body 5 is guided by the outer peripheral portion of a pressing rod (described later) 25b and the inner peripheral wall 8a of the valve chamber 8 so that the bellows 11 can be smoothly expanded and contracted vertically. The valve body 5 is moved up and down smoothly when the valve is opened and closed.

  Next, as shown in FIGS. 1, 3, and 4, the lid box 2 is a cylindrical block body, and a female screw portion that can be screwed into the male screw portion 9 of the valve box 1 is provided at a lower portion inside the lid box 2. 21 is formed, a cylinder chamber 22 for accommodating the urging means 7 is formed in the upper and lower intermediate portions, and a nut portion 23 which is a female screw for supporting the pressure adjusting mechanism 6 is formed in the upper portion. Yes. The nut portion 23 is configured to have a sufficiently long length so that a pressure adjusting screw (described later) 27 that receives the urging force of the urging means 7 is sufficiently screwed. Further, the lid box 2 is formed with an air hole 30 that communicates the outside with the cylinder chamber 22 that is an internal space in which the biasing means 7 is accommodated. The air hole 30 may be a means for forming an upper spring receiver (described later) 24, a pressure adjusting screw (described later) 27, and a knob (described later) 29 as a hole (not shown) penetrating vertically.

  As shown in FIGS. 3 and 4, the biasing means 7 includes upper and lower spring receivers 24 and 25 that are slidably fitted in the cylinder chamber 22, and upper and lower spring receivers 24 and 25. It comprises a coil spring 26 made of spring steel interposed therebetween. The upper spring receiver 24 is made of stainless steel with a substantially downward U-shaped cross section, and the lower spring receiver 25 is a spring receiver 25a having a substantially upward U-shaped cross section and a columnar cylinder of the valve body 5. A pressing rod (an example of a rod-like member) 25b fitted inside the hole 20 is integrally formed of a stainless steel. That is, the urging means 7 has a structure in which the tip of the pressing rod 25 b inserted into the cylindrical hole 13 presses the valve portion 10 by an elastic restoring force in the extension direction of the coil spring 26.

  As shown in FIGS. 1, 3, and 4, the pressure adjusting mechanism 6 is provided at the upper end portion of the pressure adjusting screw 27, the lock nut 28, and the pressure adjusting screw 27 that are screwed into the nut portion 23 of the lid box 2. It is composed of a PP (polypropylene) knob 29 that is externally fitted in an integrally rotated state, and a contact seat 27 a having a large diameter that contacts the upper spring receiver 24 is formed at the lower end portion of the pressure adjusting screw 27. Has been. As shown in FIG. 2, the pressure adjusting screw 27 has two operation holes 27 h that are opened on the lower surface of the contact seat 27 a on both sides of the valve shaft center P. These operation holes 27h are for rotating the pressure adjusting screw 27 when the pressure adjusting screw 27 is screwed from the cylinder chamber 22 to the nut portion 23. For example, a pair of tool tips of radio pliers is used. The part can be inserted into the operation hole 27h and rotated easily. As another example of replacing the operation hole 27h, a means for forming a screwdriver insertion hole having a minus or plus shape on the valve shaft center P is possible.

  When the pressure adjusting screw 27 made of fluororesin (PTFE or the like) is screwed into a predetermined position with respect to the lid box 2, the lock nut 28 made of fluororesin (PTFE or the like) is turned to fix the pressure adjusting screw 27. Since the position of the upper spring receiver 24 is determined by the position of the pressure adjusting screw 27 with which it contacts, the lock nut 28 is loosened to adjust the position of the pressure adjusting screw 27 with respect to the lid box 2 in the direction of the valve axis P. Thus, the force by which the valve unit 10 pushes the communication port 3A, that is, the relief pressure can be adjusted and set.

  At the upper end of the pressure adjusting screw 27, an upper end shaft portion 27b having a cross-sectional shape that fits the knob 29 in a relatively non-rotatable manner is formed, and an insertion hole 29a having the same shape as that is formed in the knob 29. . The knob 29 inserted into the upper end shaft portion 27b is prevented from coming off from the upper end shaft portion 27b by inserting the tip of a set screw 31 screwed into the upper end shaft portion 27b into the horizontal hole 27c of the upper end shaft portion 27b. It has a structure.

  Next, functions and the like of the pressure regulating valve A will be described. Since the movable part for following the reciprocating movement of the valve part 10 and sealing between the valve part 10 and the valve box 1 is used as the valve body 5, the bellows 11 is used. While the size can be made compact, the valve unit 10 can move with ease even if the movement of the valve unit 10 is large. Compared with the diaphragm type, the valve can withstand high pressure and can be made compact. is there. In this case, since the inside and outside of the bellows 11 are guided by the outer peripheral portion of the pressing rod 25a of the lower spring receiver 25 and the inner peripheral portion of the valve chamber 8, the bellows during the valve opening and closing operations. The up-and-down movement of No. 11 is performed smoothly without falling over or deforming, contributing to the realization of a pressure regulating valve that has a good opening and closing operation and good responsiveness.

  The components constituting the pressure regulating valve A are all made of fluororesin except for the upper and lower spring receivers 24 and 25, the coil spring 26, and the knob 29, so that they are excellent in chemical resistance, have a resistance to the external atmosphere, and have a high temperature. Can withstand high pressure.

  In the pressure regulating valve A, when the fluid pressure in the supply side flow path 3 increases and the valve body 5 is pushed up to open and move, the valve body 5 that partitions the valve chamber 8 and the cylinder chamber 22 moves upward. As a result, the cylinder chamber 22 is compressed. In this case, since the cylinder chamber 22 is almost in a closed chamber state, the volume of the space portion on the cylinder chamber 22 side is reduced and compressed by the rise of the valve body 5 due to the bellows 11 being contracted and deformed. The reaction force also acts on the valve body 5, and it is difficult for the valve body 5 to move upward and the responsiveness deteriorates, and inconveniences such as hunting due to fluid pressure fluctuations easily occur.

  However, according to the present invention, since the air hole 30 that communicates between the cylinder chamber 22 and the outside of the lid box 2 is provided, the air in the space portion on the cylinder chamber 22 side partitioned by the valve body 5 is compressed (or expanded). ), The valve body 5 can be quickly moved up and down and the valve opening operation is instantaneously performed, and the valve body 5 is hunted. A difficult effect is obtained. In order to obtain such an excellent effect, the ratio Y: D, which is the ratio between the volume Ycc (ml) of the space portion on the cylinder chamber 22 side and the diameter Dmm of the air hole 30, is set to 10: 1 to 5: 1. It is preferable to set in the range.

  The movement direction of the valve body 5 for opening and closing the communication port 3A and the direction of the supply side flow path 3 are set to be the same, and the direction X of the discharge side flow path 4 is orthogonal to this direction P, that is, L Since it is configured as a letter-shaped flow path, the flow of the fluid when the valve body 5 is moved upward and opened by the pressure increase only needs to be changed by 90 degrees from the upward movement to the lateral movement. The pressure loss when passing through can be kept small. In the above-mentioned Patent Document 1, the directions of the supply-side flow path and the discharge-side flow path are the same, and the flow of the fluid at the time of valve opening is a path that bends at right angles: lateral direction → upward → lateral direction → downward → lateral direction. Is a structure in which the direction of the flow changes 360 degrees continuously for a total of 360 degrees. Compared with this, the pressure regulating valve A of the present invention is clearly advantageous.

  Moreover, in the thing of the patent document 1 mentioned above, in order to avoid the enlargement of a fluid channel | path part, the thickness of the valve seat which a valve body, ie, a diaphragm contacts, must be made thin, and it is not suitable for high pressure. On the other hand, in the pressure regulating valve A of the present invention, the thickness of the bottom surface 8c of the valve chamber 8, which is the valve seat, that is, the lower thickness of the valve box 1 is sufficiently increased so that the strength is sufficient. It can be set and is advantageous to withstand high pressure and high temperature. In addition, the diaphragm type having a large area is disadvantageous in that it easily vibrates, but the bellows type valve element 5 is advantageous in that the pressure receiving area can be reduced and vibration is difficult.

  When the lid box 2 is screwed to the valve box 1 and tightened, the bottom surface 12b of the outer peripheral flange 12B sandwiched between the upper and lower sides of these two 2, 1 is formed on the seal surface 1a as shown in FIG. The seal lip 19 is pierced (bite in), thereby exerting a strong sealing function. However, if the outer peripheral flange 12B deteriorates (weakens) due to a change over time or the like, the excellent sealing performance due to the sticking of the seal lip 19 may be lowered. By setting it as a consumable part that replaces the valve box 1, the valve box 1 having a large size and high cost can be used several times for the valve body 5, thereby achieving both durability and cost merit. .

  When the resin is used as the valve seal structure in which the valve portion 10 and the valve seat 8c come into contact with each other, a seal lip is generally provided on one side as in the seal structure of the valve box 1 and the outer peripheral flange 12B. The sealing performance is likely to deteriorate due to changes over time. Therefore, by interposing an elastic O-ring 13 between the valve part 10 and the valve seat 8c (see FIG. 8), it is possible to flexibly cope with the operation in the vertical direction (movement direction of the valve part 10), When the sealing performance deteriorates, it can be easily improved by replacing the O-ring 13 parts.

Overall front view of pressure control valve Bottom view of FIG. Sectional view showing structure of pressure control valve Sectional view showing the open state of the pressure control valve Cross section of a single valve box The enlarged view which shows the A section of FIG. Enlarged sectional view of the main part showing the pipe joint structure Cross section of a single valve body The enlarged view which shows the A section of FIG.

Explanation of symbols

1 Valve box 2 Lid box 3 Supply side flow path 3A Communication port 4 Discharge side flow path
4a opening edge 5 valve body 7 urging means 8 recessed space 8a peripheral wall 10 valve part
10a bottom
10b peripheral surface 11 bellows 12 flange portion 22 internal space 25a rod-shaped member 26 coil spring 30 air hole A pressure regulating valve

Claims (7)

A lid having a communication port between the supply side channel and the discharge side channel, a valve box having a valve body for opening and closing the channel, and a biasing means for biasing the valve body so that the communication port is closed. And when the pressure of the supply side flow path exceeds a predetermined value, the valve body is opened and moved against the urging force of the urging means, the communication port is opened, and the supply side A pressure regulating valve configured to maintain a closed state of the communication port when the pressure of the flow path is a predetermined value or less,
The valve body can be freely opened and closed by a bottom surface at the tip , and a valve portion to which the urging force is applied is formed integrally with the valve portion in an airtight manner. The other end is configured with a bellows fixed in an airtight manner ,
The pressure regulating valve , wherein the height of the peripheral surface rising from the bottom surface of the valve portion is set to be larger than the diameter of the opening edge of the discharge-side flow passage formed facing the peripheral surface .   The pressure regulating valve according to claim 1, wherein an air hole is formed in the lid box to communicate the outside of the lid box with an internal space in which the urging means is accommodated.   The moving direction of the valve body for opening and closing the communication port and the direction of the supply side flow path are set to be the same, and the direction of the discharge side flow path is orthogonal to this direction. The pressure regulating valve according to claim 1 or 2.   The biasing means is a coil spring that elastically biases the valve portion via a rod-shaped member, and the bellows has an inner peripheral portion guided by the rod-shaped member and an outer peripheral portion that is a valve of the valve box. The pressure regulating valve according to any one of claims 1 to 3, wherein the pressure regulating valve is formed in a bellows tube shape guided by a peripheral wall of a recessed space for accommodating a body.   The pressure regulating valve according to claim 4, wherein the discharge-side flow path is configured to open to a peripheral wall of the recessed space, and a distal end periphery of the valve portion is chamfered.   2. The valve portion and the bellows are integrally formed of a synthetic resin material, and the lid box side end portion is formed in a flange portion that is sandwiched between the valve box and the lid box. The pressure regulation valve as described in any one of -5.   The pressure regulating valve according to claim 6, wherein the synthetic resin material is a fluororesin.

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