JP7649276B2 - Fluid Control Valve - Google Patents

Description

The present invention relates to a fluid control valve that controls a fluid by moving a valve body into or out of contact with a valve seat.

Fluid control valves are known that control fluid by bringing a valve disc into contact with or away from a valve seat. The fluid control valve comprises an actuator connected to the valve disc, and a valve body with a valve seat, and the actuator and valve body are connected using a mounting bolt. Fluid control valves include normally closed type valves in which the valve disc seals against the valve seat to block the flow path when the actuator does not operate. In normally closed type fluid control valves, the actuator has a built-in compression spring that generates a sealing load to seal the valve disc against the valve seat.

JP 2019-23816 A

For example, to prevent the intrusion of impurities and for sanitation management, fluid control valves undergo periodic maintenance such as replacing the valve body and cleaning the flow path. During maintenance, the mounting bolts are removed to separate the valve body from the actuator, and the mounting bolts are tightened to connect the valve body to the actuator. In normally closed type fluid control valves, the spring force of the compression spring is set strong so that the flow path is completely blocked when the valve is closed. The load of the compression spring acts on the fastening part of the mounting bolt. Therefore, when removing the mounting bolt to separate the valve body from the actuator, the fastening part of the mounting bolt may be burned or damaged by the load of the compression spring. In addition, when connecting the valve body and the actuator using the mounting bolt, the mounting bolt must be tightened against the compression spring, which increases the torque required to tighten the mounting bolt.

Conventionally, normally closed type fluid control valves have had their mounting bolts removed with the actuator in the valve open position. This reduces the load of the compression spring acting on the fastening portion of the mounting bolt, but it is time-consuming because the actuator must be made to open the valve every time the mounting bolt is removed or replaced.

The fluid control valve that has been developed to solve the above-mentioned problems is (1) a fluid control valve that includes a valve body with a valve seat, a valve element that abuts against or moves away from the valve seat, an actuator that is connected to the valve element and has a built-in compression spring that urges the valve element toward the valve seat, and a number of mounting bolts that attach the valve body to the actuator, and is configured to be manually operable and to have a stopper mechanism that limits the operation of the actuator when the number of mounting bolts are attached or detached.

In the fluid control valve of the above configuration, when the mounting bolt is attached or detached, the stopper mechanism limits the operation of the actuator without the actuator being operated to open the valve in order to reduce the load of the compression spring. This reduces the load of the compression spring acting on the fastening part of the mounting bolt when the mounting bolt is attached or detached. Therefore, when the mounting bolt is removed to separate the valve body and the actuator, the fastening part of the mounting bolt can be prevented from burning or being damaged. In addition, when the valve body and the actuator are connected using the mounting bolt, there is no need to fasten the mounting bolt against the compression spring, and the torque required to fasten the mounting bolt can be reduced. Therefore, according to the above configuration, in a normally closed type fluid control valve in which the valve body is attached to the actuator using the mounting bolt, the mounting bolt can be easily attached and detached without operating the actuator.

(2) In the fluid control valve described in (1), it is preferable that the valve has an indicator that is exposed to the outside of the actuator and displaces in response to the operation of the actuator, and the stopper mechanism has a stopper member that is attached to the indicator and engages with the actuator, and a screw portion that is provided between the stopper member and the indicator and adjusts the position of the stopper member.

The fluid control valve with the above configuration allows the screw mechanism to be provided in a compact structure because the position at which the stopper member limits the actuator movement can be adjusted by the screw portion.

(3) In the fluid control valve described in (2), it is preferable that the stopper mechanism has a fixing member that fixes the position of the stopper member.

The fluid control valve of the above configuration can, for example, prevent the position of the stopper member from shifting due to vibrations that occur when the fluid control valve is opened or closed.

(4) In the fluid control valve described in (2) or (3), it is preferable that a gap is formed between the stopper member and the actuator when the fluid control valve is closed.

When the fluid control valve of the above configuration is closed, a gap is formed between the stopper member and the actuator, so the stopper mechanism does not impair the sealing performance of the fluid control valve when the valve is closed.

(5) In the fluid control valve described in (4), it is preferable to have a gap management mechanism that manages the gap size.

The fluid control valve with the above configuration allows anyone to easily adjust the gap when assembling the fluid control valve, for example.

(6) In the fluid control valve described in any one of (1) to (5), the valve seat is provided by a seal surface provided to cross the flow path formed in the valve body, and the valve body is a diaphragm having a deformation portion that deforms in response to the operation of the actuator to abut against or move away from the seal surface, and a flat portion that is provided flat along the outer edge of the deformation portion and has a plurality of insertion holes through which the mounting bolt is inserted, and the actuator has a first flange portion that is in surface contact with one surface of the flat portion and has a plurality of female threaded holes through which the mounting bolt is fastened, and the valve body has a second flange portion that is in surface contact with the other surface of the flat portion and has a plurality of through holes through which the mounting bolt passes.

The fluid control valve of the above configuration is a wear-type diaphragm valve in which the flat portion of the diaphragm is crushed between the first flange portion of the actuator and the second flange portion of the valve body to form a seal, and the deformed portion of the diaphragm is brought into contact with or separated from a sealing surface provided across the flow path. This type of fluid control valve is convenient because the stopper mechanism can be manually operated to limit the operation of the actuator to make it easier to replace the diaphragm.

The technology disclosed in this specification makes it possible to easily attach and detach the mounting bolts in a normally closed type fluid control valve in which the valve body is attached to the actuator using the mounting bolts without operating the actuator.

FIG. 2 is a side view of the fluid control valve. FIG. 2 is a bottom view of the fluid control valve. 2 is a cross-sectional view taken along line AA of FIG. 1. FIG. 2 is an exploded perspective view of the fluid control valve. FIG. 2 is an exploded perspective view of the fluid control valve. FIG. 13 is a cross-sectional view of a fluid control valve that does not include a stopper mechanism. 7 shows the fluid control valve shown in FIG. 6 with the mounting bolts loosened. 1 shows a fluid control valve equipped with a stopper mechanism with a mounting bolt loosened.

The technology disclosed in this specification is explained below with reference to the drawings. The technology disclosed in this specification is applied to a normally closed type fluid control valve in which the valve body and the actuator are connected using a mounting bolt.

Figure 1 is a side view of a fluid control valve 1. The fluid control valve 1 of this embodiment is a normally closed type Weir-type diaphragm valve. A Weir-type diaphragm valve is a valve that controls a fluid by abutting or separating a diaphragm against a sealing surface that is provided across the flow path. Weir-type diaphragms are less likely to leave fluid in the liquid-contacting area, and are used, for example, in manufacturing equipment for pharmaceuticals, food, fuel cells, etc. In the fluid control valve 1, a diaphragm 4 is disposed between an actuator 2 and a valve body 3, and the actuator 2 and the valve body 3 are connected using multiple mounting bolts 5.

Figure 2 is a bottom view of the fluid control valve 1. In this embodiment, the fluid control valve 1 has the valve body 3 attached to the actuator 2 using four mounting bolts 5. Note that the number and arrangement of the mounting bolts 5 are not limited to this embodiment.

Returning to FIG. 1, the fluid control valve 1 is equipped with an indicator 73 that indicates the operating state of the fluid control valve 1. The indicator 73 is provided with a stopper mechanism 7. The stopper mechanism 7 can be manually operated and limits the operation of the actuator 2 when the multiple mounting bolts 5 are attached or detached. The stopper mechanism 7 will be described later.

Figure 3 is a cross-sectional view taken along line A-A in Figure 1. The actuator 2 is an air-operated driving device that operates using operating air. The actuator 2 includes a cylinder 21, a piston 23, a compression spring 26, a piston rod 27, a rod cover 28, a compressor 29, and an indicator 73. The piston 23 is slidably mounted in a piston chamber 22 provided in the cylinder 21, and air-tightly divides the piston chamber 22 into a first chamber 22A and a second chamber 22B.

As shown in FIG. 1, the cylinder 21 has an operation port 24 that communicates with the first chamber 22A, and a breathing hole 25 that communicates with the second chamber 22B. An operation air control device (not shown) is connected to the operation port 24 and controls the internal pressure of the first chamber 22A by supplying and exhausting operation air to the first chamber 22A. The breathing hole 25 is open to the atmosphere, allowing air to flow freely in and out of the second chamber 22B.

As shown in FIG. 3, the compression spring 26 is compressed in the second chamber 22B and constantly biases the piston 23 toward the valve body 3 (downward in the figure). The actuator 2 allows the piston 23 to move up and down in the cylinder 21 according to the balance between the internal pressure of the first chamber 22A and the spring force of the compression spring 26.

A piston rod 27 and an indicator 73 are connected to the piston 23. A connecting screw 20 is insert-molded into the upper end of the piston rod 27 in the figure. The connecting screw 20 of the piston rod 27 penetrates the piston 23 from the valve body 3 side, and the indicator 73 is screwed into the connecting screw 20 from the side opposite the valve body 3, so that the piston rod 27 and the indicator 73 are attached integrally.

The piston rod 27 is slidably inserted into the end face (lower end face in the figure) of the cylinder 21 located on the valve body 3 side. The rod cover 28 is cylindrical and is screwed to the lower end face of the cylinder 21 in the figure. The lower end of the piston rod 27 is disposed inside the rod cover 28. Inside the rod cover 28, a compressor 29 is disposed so as to be movable in the vertical direction in the figure while being prevented from rotating. The lower end of the piston rod 27 is connected to this compressor 29. The end face (lower end face in the figure) of the compressor 29 located on the valve body 3 side is spherical and protrudes toward the valve body 3 side, and is connected to the diaphragm 4.

The valve body 3 is made of a metal such as stainless steel. The valve body 3 has a straight flow path 31. The valve body 3 has an opening 34 that connects the actuator 2 side to the flow path 31. Note that the flow path 31 does not have to be straight.

The valve body 3 has a weir portion 32 inside the flow path 31. The weir portion 32 is provided at a position corresponding to the opening 34 so as to cross the flow path 31. The flow path 31 is divided into a first flow path portion 31A and a second flow path portion 31B by the weir portion 32. The weir portion 32 is provided so that the cross section cut along the flow path axis direction has a mountain shape in order to reduce the fluid remaining in the flow path 31. The weir portion 32 has an internal seal surface 33 at its top, and a space can be formed between the diaphragm 4 and the internal seal surface 33 to communicate the first flow path portion 31A and the second flow path portion 31B. The internal seal surface 33 is provided in an arc shape with the center portion lower than both ends, corresponding to the lower end surface of the compressor 29.

The diaphragm 4 is made of a resin such as a fluororesin, and its surface is coated with rubber to improve sealing performance. The diaphragm 4 has a deformation portion 41 and a flat portion 42.

The deformation portion 41 is dome-shaped, with a seal portion 46 protruding from its apex located on the valve body 3 side. The seal portion 46 is provided straight along the diameter direction. The diaphragm 4 is insert-molded in the center of the deformation portion 41 so that the connecting shaft 47 protrudes toward the actuator 2 side. The connecting shaft 47 and the compressor 29 are connected by rotating the diaphragm 4 90° forward, and are disconnected by rotating the diaphragm 4 90° reverse. The flat portion 42 extends outward from the outer edge of the deformation portion 41 and is provided flat along the outer edge of the deformation portion 41.

The diaphragm 4 has its flat portion 42 sandwiched between the actuator 2 and the valve body 3, with its sealing portion 46 facing the internal sealing surface 33. The load of the compression spring 26 built into the actuator 2 is transmitted via the compressor 29, piston rod 27, and piston 23, and the sealing portion 46 of the diaphragm 4 is pressed against the internal sealing surface 33 to seal. The deformation portion 41 of the diaphragm 4 abuts against or moves away from the internal sealing surface 33 depending on the movement of the piston 23. The diaphragm 4 is an example of a valve body. The internal sealing surface 33 is an example of a valve seat.

Figures 4 and 5 are exploded perspective views of the fluid control valve 1. The flat portion 42 of the diaphragm 4 is rectangular. As shown in Figure 4, the flat portion 42 has a first annular protrusion 43 provided in an annular shape on the outside of the deformation portion 41 on the surface (upper surface in the figure) located on the actuator 2 side. As shown in Figure 5, the flat portion 42 has a second annular protrusion 44 provided in an annular shape on the outside of the deformation portion 41 on the surface (lower surface in the figure) located on the valve body 3 side. The flat portion 42 has insertion holes 45 formed at the four corners outside the first annular protrusion 43 and the second annular protrusion 44, through which the mounting bolts 5 are inserted.

As shown in FIG. 5, the rod cover 28 of the actuator 2 is provided with a first flange portion 28a at the end (lower end in the figure) located opposite the cylinder 21. The first flange portion 28a is provided in a rectangular shape corresponding to one surface of the flat portion 42 so as to be in surface contact with one surface of the flat portion 42. The first flange portion 28a has a first annular groove 28b formed in an annular shape on the surface located on the valve body 3 side (lower surface in the figure), into which the first annular protrusion 43 is attached. The first flange portion 28a has female threaded holes 28c formed in the four corners outside the first annular groove 28b, into which the mounting bolts 5 are fastened.

As shown in FIG. 4, the valve body 3 has a second flange portion 35 at a portion facing the actuator 2. A cylindrical opening 34 is formed in the center of the second flange portion 35. The second flange portion 35 is formed in a rectangular shape corresponding to the flat portion 42 so as to be in surface contact with the other surface of the flat portion 42. The second flange portion 35 has a second annular groove 36 formed in an annular shape on the surface (top surface in the figure) located on the actuator 2 side, into which the second annular protrusion 44 is attached. The second flange portion 35 has through holes 37 formed at the four corners outside the second annular groove 36, through which the mounting bolts 5 pass.

As shown in Figures 4 and 5, the mounting bolts 5 are inserted through the through holes 37 of the valve body 3 and the insertion holes 45 of the diaphragm 4 via the washers 6, and are then fastened to the female threaded holes 28c of the actuator 2. This attaches the valve body 3 to the actuator 2 via the diaphragm 4.

As shown in FIG. 3, when the mounting bolts 5 are tightened, the flat portion 42 of the diaphragm 4 is crushed between the first flange portion 28a and the second flange portion 35 of the fluid control valve 1, forming a sealing surface on the outside of the deformation portion 41. This prevents the fluid flowing through the flow path 31 of the valve body 3 from leaking out from between the actuator 2 and the valve body 3.

The above-mentioned stopper mechanism 7 will now be described. As shown in Figures 3 and 4, the stopper mechanism 7 includes a stopper nut 71, a lock nut 72, and a threaded portion 74. The stopper nut 71 is an example of a stopper member. The lock nut 72 is an example of a fixing member.

The threaded portion 74 is composed of a male threaded portion 73a provided on the outer peripheral surface of the indicator 73 and a female threaded portion 71a formed on the inner peripheral surface of the stopper nut 71. The indicator 73 is rod-shaped. The indicator 73 is slidably inserted into the end face (upper end face in the figure) of the cylinder 21 located opposite the valve body 3, and the upper end is exposed to the outside of the actuator 2. The lower end of the indicator 73 is connected to the piston 23, and the position of the upper end is displaced in response to the movement of the piston 23. In other words, the indicator 73 is displaced in response to the movement of the actuator 2.

As shown in FIG. 3, the stopper nut 71 is attached to the indicator 73 via a threaded portion 74 so that its position can be adjusted. The stopper nut 71 has a size larger than the insertion hole formed in the cylinder 21 for inserting the indicator 73, and is engaged with the cylinder 21 to limit the movement of the actuator 2.

The position of the stopper nut 71 is adjusted so that a gap S is formed between the stopper nut 71 and the cylinder 21 when the fluid control valve 1 is closed. The gap S is set within a range in which the stopper nut 71 does not interfere with the closing operation of the fluid control valve 1.

It is preferable that the gap S be set within a range that allows for deformation of the diaphragm 4 and the seal portion 46. If the gap S is set to a value smaller than the lower limit of the range that allows for deformation of the diaphragm 4 and the seal portion 46, the compression spring 26 may not be able to provide a sufficient valve closing force. If the gap S is set to a value that significantly exceeds the upper limit of the range that allows for deformation of the diaphragm 4 and the seal portion 46, the load of the compression spring 26 acts on the fastening portion of the mounting bolt 5 over a wider range when the mounting bolt 5 is attached or detached, making it difficult to disassemble and assemble the valve.

The lock nut 72 is screwed onto the male threaded portion 73a of the indicator 73. The lock nut 72 is tightened onto the male threaded portion 73a from the side opposite the cylinder 21 so that it abuts against the stopper nut 71, preventing the stopper nut 71 from loosening. In other words, the position of the stopper nut 71 is fixed by the lock nut 72.

As shown in FIG. 4, the spacer 8 is U-shaped. The spacer 8 has a thickness according to the width of the gap S, and manages the width of the gap S when the stopper nut 71 is tightened onto the male threaded portion 73a. The spacer 8 is disposed between the stopper nut 71 and the cylinder 21 when assembling the fluid control valve 1, and is removed from the fluid control valve 1 after assembly is complete. The spacer 8 is an example of a gap management mechanism.

Next, the operation of the fluid control valve 1 will be described. In this embodiment, it is assumed that the fluid flows from the first flow path portion 31A to the second flow path portion 31B. As shown in FIG. 3, when the operating air is not supplied to the first chamber 22A, the piston 23 is biased by the compression spring 26 to seal the seal portion 46 of the diaphragm 4 against the internal seal surface 33. The flow path 31 is blocked between the first flow path portion 31A and the second flow path portion 31B, and the fluid does not flow from the first flow path portion 31A to the second flow path portion 31B.

When the first chamber 22A of the fluid control valve 1 is supplied with operating air, the piston 23 rises to a position where the internal pressure of the first chamber 22A and the spring force of the compression spring 26 are balanced. The diaphragm 4 is deformed as the deformation portion 41 is pulled up by the piston 23 via the compressor 29 and piston rod 27, and the seal portion 46 is separated from the internal seal surface 33. The fluid flows from the first flow path portion 31A to the second flow path portion 31B through the space between the seal portion 46 and the internal seal surface 33.

After that, when the operating air is discharged from the first chamber 22A, the piston 23 of the fluid control valve 1 is urged downward by the compression spring 26. The deformation portion 41 of the diaphragm 4 is pulled downward by the piston 23 via the compressor 29 and piston rod 27, and deforms, coming into contact with the internal seal surface 33. The spring force of the compression spring 26 is transmitted to the diaphragm 4 via the piston 23, piston rod 27, and compressor 29, and the seal portion 46 seals against the internal seal surface 33. This prevents fluid from flowing from the first flow path portion 31A to the second flow path portion 31B.

The fluid control valve 1 can repeatedly open and close in the manner described above. In this case, the indicator 73 moves up and down integrally with the piston 23. In other words, the position of the upper end of the indicator 73 changes in accordance with the stroke of the actuator 2. Therefore, the operating state of the fluid control valve 1 can be confirmed based on the position of the upper end of the indicator 73.

The stopper nut 71 is positioned to form a gap S between it and the cylinder 21. Therefore, the stopper nut 71 does not impair the sealing performance of the fluid control valve 1 when the valve is closed.

The stopper nut 71 may move due to vibrations that occur when the fluid control valve 1 opens and closes. However, the lock nut 72 limits the movement of the stopper nut 71. Therefore, even if the fluid control valve 1 repeatedly opens and closes, the stopper nut 71 does not shift from its initial position and the gap S can be maintained.

Next, the procedure for replacing the diaphragm 4 will be described. Before describing the fluid control valve 1 of this embodiment, the mounting bolt 5 of the fluid control valve 1X that does not have a stopper mechanism 7 will be described.

Figure 6 is a cross-sectional view of the fluid control valve 1X. In the fluid control valve 1X, the indicator 73X does not have a male thread portion 73a, and the stopper nut 71 and the lock nut 72 are not screwed onto the indicator 73. This is different from the fluid control valve 1 of this embodiment in which the stopper nut 71 and the lock nut 72 are screwed onto the male thread portion 73a formed on the indicator 73. Note that, among the configurations of the fluid control valve 1X, the same reference numerals as those of the fluid control valve 1 are used for the configurations that are common to the fluid control valve 1.

Figure 7 shows the fluid control valve 1X shown in Figure 6 with the mounting bolt 5 loosened. When the mounting bolt 5 is loosened in the fluid control valve 1X in a valve-closed state in which the actuator 2 is not operating and the diaphragm 4 is in contact with the internal seal surface 33, the compression spring 26 expands as the mounting bolt 5 is loosened. Because the fluid control valve 1X does not have a stopper mechanism 7, the compression spring 26 can expand until the piston 23 engages with the inner wall of the cylinder 21.

In the fluid control valve 1X, while the mounting bolt 5 is being loosened, the spring force of the compression spring 26 presses the diaphragm 4 against the internal seal surface 33. As a result, the actuator 2 is pushed up in a direction away from the valve body 3 as the compression spring 26 expands. Therefore, the load of the compression spring 26 acts on the fastening portion between the mounting bolt 5 and the female threaded hole 28c shown as P1 in the figure in the direction opposite to the direction in which the mounting bolt 5 is loosened.

In a normally closed type fluid control valve 1X, the spring force of the compression spring 26 is set strong to obtain a sealing load when the valve is closed. Therefore, the load of the compression spring 26 acting on the fastening portion of the mounting bolt 5 is large. If the mounting bolt 5 is forcibly rotated in this state, there is a risk that the threaded portion shown as P1 in the figure will seize or be damaged.

Therefore, before removing the mounting bolt 5, the fluid control valve 1X supplies operating air to the first chamber 22A to cause the actuator 2 to open the valve. This prevents the load of the compression spring 26 from acting on the portion where the mounting bolt 5 is screwed into the female threaded hole 28c. Therefore, the mounting bolt 5 can be removed without damaging the portion where it is fastened to the female threaded hole 28c.

When the valve body 3 is removed from the actuator 2, the operating air of the fluid control valve 1X is discharged from the first chamber 22A. This causes the diaphragm 4 to no longer be pressed against the first flange portion 28a. The diaphragm 4 is rotated 90° in the opposite direction, which releases the connection between the connecting shaft 47 and the compressor 29 and allows it to be removed from the compressor 29.

When the new diaphragm 4 is rotated 90° in the forward direction to connect the connecting shaft 47 to the compressor 29, the fluid control valve 1X supplies operating air to the first chamber 22A of the actuator 2, causing the actuator 2 to open the valve. This eliminates the need for the mounting bolt 5 to be tightened into the female threaded hole 28c against the compression spring 26, and allows it to be tightened into the female threaded hole 28c with a small torque.

The fluid control valve 1X makes it easy to attach and remove the mounting bolt 5 by supplying operating air to the first chamber 22A to cause the actuator 2 to open the valve before removing or fastening the mounting bolt 5. However, with this method, operating air must be supplied to the actuator 2 to open the valve every time the mounting bolt 5 is attached or removed, which is time-consuming.

In contrast, the fluid control valve 1 is equipped with a stopper mechanism 7, which makes it easy to attach and remove the mounting bolt 5 without operating the actuator 2. The procedure for replacing the diaphragm 4 of the fluid control valve 1 will be described with reference to Figure 8. Figure 8 shows the fluid control valve 1 equipped with the stopper mechanism 7 with the mounting bolt 5 loosened.

The fluid control valve 1 loosens the mounting bolt 5. When the mounting bolt 5 begins to be loosened, the compression spring 26 tries to expand. However, when the piston 23 is urged by the compression spring 26 and moves toward the valve body 3 by the gap S, the stopper nut 71 is locked to the cylinder 21. The piston 23 of the actuator 2 is locked to the cylinder 21 via the indicator 73 and the stopper nut 71, and cannot move any further toward the valve body 3. In other words, the operation of the actuator 2 is restricted.

When the operation of the actuator 2 is restricted, the load of the compression spring 26 does not act on the threaded portion between the mounting bolt 5 and the female threaded hole 28c shown in P2 in the figure, even if operating air is not supplied to the first chamber 22A. Therefore, the fluid control valve 1 can avoid the threaded portion between the mounting bolt 5 and the female threaded hole 28c shown in P2 in the figure from burning or breaking when loosening the mounting bolt 5, even if the actuator 2 is not supplied with operating air to open the valve, as in the fluid control valve 1X.

While the mounting bolt 5 is being loosened by the gap S between the stopper nut 71 and the cylinder 21, the load of the compression spring 26 acts on the fastening portion of the mounting bolt 5. However, the gap S is a very small gap that is set within a range that allows deformation of the diaphragm 4 and the seal portion 46. Therefore, the load of the compression spring 26 acts on the fastening portion of the mounting bolt 5 only for the moment when the mounting bolt 5 begins to be loosened, and the load of the compression spring 26 does not act on the majority of the time the mounting bolt 5 is loosened. Therefore, the fluid control valve 1 requires less torque to loosen the mounting bolt 5 compared to the fluid control valve 1X.

When the mounting bolt 5 of the actuator 2 is loosened, the compression spring 26 pushes the diaphragm 4 toward the valve body 3 via the piston 23, piston rod 27, and compressor 29 by the amount of gap S. This automatically creates a gap S2 between the flat portion 42 of the diaphragm 4 and the first flange portion 28a of the actuator 2. The mounting bolt 5 of the fluid control valve 1 is removed while maintaining the gap S2, that is, while the diaphragm 4 does not protrude too much from the bottom surface of the cylinder 21.

When the existing diaphragm 4 of the fluid control valve 1 is removed from the compressor 29 after the mounting bolts 5 have been removed and the valve body 3 has been separated from the actuator 2, the diaphragm 4 is separated from the first flange portion 28a via the gap S2. Therefore, even if the actuator 2 does not exhaust the operating air to close the valve, the existing diaphragm 4 of the fluid control valve 1 can be easily removed from the compressor 29 by rotating it 90° in the reverse direction, and a new diaphragm 4 can be easily attached to the compressor 29 by rotating it 90° in the forward direction.

When the new diaphragm 4 is attached to the fluid control valve 1, the second flange portion 35 of the valve body 3 is overlapped with the first flange portion 28a of the actuator 2 via the new diaphragm 4, and the mounting bolt 5 is inserted into the through hole 37 of the second flange portion 35 and the insertion hole 45 of the diaphragm 4, respectively, and fastened to the female threaded hole 28c of the first flange portion 28a.

Even if the actuator 2 is not supplied with operating air to open the valve, the operation of the actuator 2 is restricted by the stopper mechanism 7, just as when the mounting bolt 5 is removed. In other words, the movement of the piston 23 is restricted, and the load of the compression spring 26 does not act on the diaphragm 4. When the mounting bolt 5 is fastened to the female threaded hole 28c, the load of the compression spring 26 does not act on the fastening portion of the mounting bolt 5, so the mounting bolt 5 can be fastened with a small torque. The new diaphragm 4 does not protrude too much from the bottom surface of the cylinder 21 when the fluid control valve 1 is assembled, so it is unlikely to be damaged by rubbing against other components when the valve is assembled. This completes the replacement of the diaphragm 4.

As described above, in the fluid control valve 1 of this embodiment, when the mounting bolt 5 is removed, the stopper mechanism 7 limits the operation of the actuator 2 without supplying operating air to the actuator 2 to reduce the load of the compression spring 26 and open the valve. This reduces the load of the compression spring 26 acting on the fastening portion of the mounting bolt 5 when the mounting bolt 5 is removed. Therefore, when the mounting bolt 5 is removed to separate the valve body 3 and the actuator 2, the fastening portion of the mounting bolt 5 can be prevented from burning or being damaged. In addition, when the valve body 3 and the actuator 2 are connected using the mounting bolt 5, it is not necessary to fasten the mounting bolt 5 against the compression spring 26, and the torque required for fastening the mounting bolt 5 can be reduced. Therefore, according to this embodiment, in a normally closed type fluid control valve 1 in which the valve body 3 is attached to the actuator 2 using the mounting bolt 5, the mounting bolt 5 can be easily attached and detached without operating the actuator 2. As a result, the workability of disassembling and assembling the fluid control valve 1 is improved.

The present invention is not limited to the above embodiment, but can be applied in various ways. For example, the actuator 2 is not limited to an air-operated type drive device, but may be a solenoid type drive device. The materials of each component are not limited to the above embodiment, but may be changed as appropriate depending on the application, etc.

In addition, the method of manually operating the stopper mechanism 7 is not limited to the screw structure. For example, the stopper mechanism 7 may be structured to be manually operated by a toggle handle or the like. When the stopper mechanism 7 is manually operated by a toggle handle, the stopper mechanism 7 can be easily positioned at a first position that limits the extension of the compression spring 26, or at a second position that does not limit the extension of the compression spring 26. However, if the stopper mechanism 7 is manually operated by a screw structure, the structure of the stopper mechanism 7 can be made more compact than when it is manually operated by a toggle handle, and further, it is easier to exert a strong force when restricting the operation of the actuator 2.

In addition, instead of the lock nut 72, a fixing pin may be inserted through the stopper nut 71 and the indicator 73 to fix the position of the stopper nut 71. The position of the stopper nut 71 may also be fixed. In this case, the fixing pin is an example of a fixing member. The position of the stopper nut 71 does not have to be fixed by the lock nut 72 or the like. However, if the position of the stopper nut 71 is fixed by the lock nut 72 or the like, it is possible to prevent the position of the stopper nut 71 from shifting due to vibrations during the opening and closing operations of the fluid control valve 1, for example.

Alternatively, the gap S may be omitted and the stopper nut 71 may be positioned so that it contacts the cylinder 21 when the valve is closed. However, by forming the gap S between the stopper nut 71 and the cylinder 21 when the valve is closed, the stopper mechanism 7 does not impair the sealing performance of the fluid control valve when the valve is closed.

Instead of the spacer 8, a mark showing the tightening position of the stopper nut 71 may be provided on the indicator 73 to manage the size of the gap S. This reduces the number of parts and makes parts management easier.

The gap management mechanism that manages the size of the gap S by placing the spacer 8 or providing a mark on the indicator 73 may be omitted. However, by providing a gap management mechanism that includes the spacer 8 and a mark, for example, anyone can easily adjust the size of the gap S when assembling the fluid control valve 1.

Furthermore, the fluid control valve 1 is not limited to a Weir-type diaphragm valve, but may be a valve incorporating a poppet valve, or a diaphragm valve in which a diaphragm abuts against or separates from an annular valve seat. However, if the fluid control valve 1 is a Weir-type diaphragm valve, it is convenient to manually operate the stopper mechanism 7 to limit the operation of the actuator 2 so that the diaphragm 4 can be easily replaced.

It goes without saying that the structure, operation, and maintenance work such as diaphragm replacement of the fluid control valve 1 can be modified as appropriate without departing from the spirit of the technology disclosed in this specification.

1... Fluid control valve, 2... Actuator, 3... Valve body, 4... Diaphragm, 5... Mounting bolt, 7... Stopper mechanism, 8... Spacer, 26... Compression spring, 33... Internal seal surface, 71... Stopper nut, 72... Double nut, 73... Indicator, 74... Threaded portion, S... Gap

Claims (6)

A fluid control valve comprising: a valve body having a valve seat; a valve element abutting or separating from the valve seat ; a cylinder; a piston slidably mounted in the cylinder; a piston rod applying a driving force to the valve element in response to an operation of the piston; a compression spring urging the piston toward the valve seat; and a plurality of mounting bolts for mounting the valve body to the cylinder ,
an indicator that is exposed to the outside of the cylinder and displaces in response to the movement of the piston;
a stopper member attached to the indicator and engaged with the cylinder when the mounting bolts are being attached or detached, thereby limiting the movement of the piston ;
a position adjustment mechanism for adjusting the position of the stopper member;
having
A fluid control valve configured as follows. 2. The fluid control valve according to claim 1,
The position adjustment mechanism is a screw portion provided between the stopper member and the indicator and adapted to adjust the position of the stopper member .
A fluid control valve configured as follows. 2. The fluid control valve according to claim 1 ,
A fixing member for fixing the position of the stopper member.
A fluid control valve configured as follows. 2. The fluid control valve according to claim 1 ,
When the fluid control valve is closed, a gap is formed between the stopper member and the cylinder .
A fluid control valve configured as follows. 5. The fluid control valve according to claim 4,
A gap control mechanism for controlling the gap is provided.
A fluid control valve configured as follows. The fluid control valve according to any one of claims 1 to 5 ,
the valve seat is provided by a sealing surface provided across a flow passage formed in the valve body,
the valve body is a diaphragm having a deformable portion that deforms in response to the movement of the piston to come into contact with or separate from the seal surface, and a flat portion that is provided flat along an outer edge of the deformable portion and has a plurality of insertion holes through which the mounting bolts are inserted,
the cylinder has a first flange portion that is in surface contact with one surface of the flat portion and has a plurality of female threaded holes into which the mounting bolts are fastened;
The valve body has a second flange portion that is in surface contact with the other surface of the flat portion and has a plurality of through holes through which the mounting bolts pass.
A fluid control valve configured as follows.

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