JP2005042859A - Differential pressure control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a differential pressure control valve capable of precisely controlling fluid pressure in response to adopted reference pressure by adopting reference pressure such as that of the air. <P>SOLUTION: The differential pressure control valve controls the pressure of a fluid in response to the adopted reference pressure by adopting the reference pressure such as the air. The differential pressure control valve comprises a housing 2 having a reference pressure port 9, a control pressure port 10, and an outlet port 11, a bellows 6 partitioning the housing 2 into a reference pressure chamber 3 connected with the reference pressure port 9 and a control pressure chamber 4a formed on a part of a passage which connects the control pressure port 10 and the outlet port 11, and a valve body 7 supported on the tip of the bellows 6. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a differential pressure control valve capable of taking in a gas such as air or gas and operating the opening of the valve in accordance with the taken-in gas pressure.

  Conventionally, a diaphragm, which is a membrane plate for isolation, has been provided in the valve to completely isolate the gas and liquid inside the valve from the working fluid, and a valve shaft is attached directly or indirectly to this diaphragm, thereby distorting the diaphragm. A diaphragm valve in which the valve shaft is displaced according to the amount is known. The diaphragm valve utilizes the fact that the air pressure applied to the diaphragm is proportional to the displacement of the valve shaft, and the opening of the valve is operated in response to a signal such as air pressure. The diaphragm is mainly composed of a combination of synthetic rubber and nylon, hemp, glass fiber, or a thin plate made of synthetic resin or metal.

  By the way, as this kind of diaphragm valve, there exists a thing shown in FIG. 18, for example (refer patent document 1).

  Explaining this, the diaphragm valve 30 has a housing (valve body) 31 having a flow path for fluid flow from an inlet 32 to an outlet 33, and a valve seat 40 is provided to intersect the flow path in the housing 31. It has been. A valve body 39 is provided below the valve seat 40, and the valve body 39 is connected to a support body 37 and a diaphragm 36 via a valve rod (valve shaft) 38. The diaphragm chamber 41 defined by the support 37 and the diaphragm 36 is connected to the pressure adjustment source 35 so that the diaphragm 36 is displaced by the balance between the pressure supplied from the pressure adjustment source 35 and the fluid pressure in the fluid chamber 42. It is configured. Therefore, the valve body 39 moves up and down with the displacement of the diaphragm 36, and the valve body 39 and the valve seat 40 come into contact with and separate from each other.

  FIG. 19 shows an example in which the diaphragm valve 30 is applied, and is for controlling the liquid level in the toilet tank 50.

  The diaphragm valve 30 is disposed at a height slightly below the desired liquid level in the (toilet) tank 50, and the suction pipe 53 extends from the outlet 33 of the diaphragm valve 30 to the vicinity of the bottom of the tank 50. The diaphragm chamber 41 is open to the atmosphere.

  In such a system, for example, when the tank 50 is filled with a fluid, the pressure of the fluid acting on the valve body 39 via the suction pipe 53 exceeds the atmospheric pressure in the diaphragm chamber 41. 36 is distorted to the diaphragm chamber 41 side, and the valve body 39 is closed.

  However, when the fluid in the tank 50 decreases and the tank 50 is empty or close to the state, the pressure in the suction pipe 53 is lowered below the atmospheric pressure, and the diaphragm 36 is moved to the fluid chamber 42 side. Distortion, the valve body 39 is opened. When the valve body 39 is opened, the fluid that has entered from the inlet 32 passes through the fluid chamber 42 and flows into the tank 50 from the outlet 33, so that the tank 50 is replenished with fluid. When the liquid flows into the tank 50 and the pressure in the suction pipe 53 starts to rise, the diaphragm 36 is distorted toward the diaphragm chamber 41 and the valve body 39 is closed again. When the liquid is filled in the tank 50, that is, when the liquid level in the tank 50 approaches a desired height, the valve body 39 is completely closed so that the fluid does not flow into the tank 50. Become.

  As described above, the diaphragm valve 30 controls the liquid level in the tank 50 by operating the opening of the valve in accordance with the atmospheric pressure in the diaphragm chamber 41 based on the atmospheric pressure in the diaphragm chamber 41. .

The tank 50 has a rod extending through the lid 52 to the valve 54 at the bottom of the tank 50. When the rod is raised, the valve 54 is opened and the liquid in the tank 50 is discharged.
Published Patent Publication P2003-507779

  As described above, the diaphragm valve operates the valve shaft based on the displacement or strain amount of the diaphragm, but since the diaphragm is a membrane plate made of synthetic resin or synthetic rubber, the displacement or strain amount is It's not that big. That is, the fact that the amount of displacement of the diaphragm is not so large means that the stroke range of the valve shaft that operates in proportion to the diaphragm is extremely limited.

  However, when the fluid pressure is controlled according to the atmospheric pressure as the external environment, for example, when high-precision control is required under a low pressure of about several kPa, the diaphragm or valve shaft If the stroke range is extremely limited, the pressure loss becomes large and high-precision control becomes difficult. In the above example, it becomes difficult to control the liquid level in the tank with high accuracy.

  Therefore, an object of the present invention is to provide a differential pressure control valve that takes in a reference pressure such as the atmosphere and can control the pressure of a fluid with high accuracy in accordance with the reference pressure.

  In order to solve the above problems, the present invention provides a housing having a reference pressure port, a control pressure port, and a discharge port, and a reference pressure chamber, a control pressure port, and a discharge that communicate with the reference pressure port in the housing. A bellows that divides into a control pressure chamber formed in a part of a passage connecting the port is provided. And the valve body is supported at the front-end | tip of a bellows, and it is comprised so that a valve body may also be displaced with expansion / contraction of a bellows. That is, the opening degree of the valve is operated with the expansion and contraction of the bellows.

  As described above, the reference pressure chamber and the control pressure chamber in the housing are completely separated by the bellows and the valve body, and the opening degree of the valve is controlled by the expansion and contraction of the bellows. (Stroke range) can be increased, and in controlling the pressure of the working fluid, the pressure loss can be reduced, so that highly accurate control is possible.

  Furthermore, the present invention is characterized in that a stroke regulating rod and a valve body pin for regulating the expansion / contraction range of the bellows (the stroke range of the valve body) are provided.

  By regulating the expansion / contraction range of the bellows, the responsiveness of the valve body can be improved, and buckling and plastic deformation of the bellows can be prevented.

  Furthermore, the present invention is characterized in that a predetermined gap for allowing fluid to flow is provided in a portion where the valve body and the valve body pin are fitted.

  As a result, the gap portion serves as a kind of orifice, and finer damping force control is possible.

  The differential pressure control valve according to the present invention divides the inside of a housing into a reference pressure chamber and a control pressure chamber by a bellows, and supports the valve body at the tip of the bellows, thereby operating the opening of the valve by the expansion and contraction of the bellows. Since it did in this way, the stroke range of a valve body can be taken large, pressure loss can be reduced, and more highly accurate control is attained. Further, since the bellows is expanded and contracted based on the reference pressure, minute pressure control of the fluid can be stably performed.

  Further, by providing a stroke restricting rod and a valve body pin and restricting the expansion / contraction range of the bellows, the responsiveness of the valve can be improved, and buckling and plastic deformation of the bellows can be prevented.

  Furthermore, since a predetermined gap is provided in a fitting portion between the valve body pin and the concave portion such as the valve body, and a fluid flows in this gap portion, a damping force is generated here, so that finer details are obtained. Control becomes possible.

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

  As shown in FIG. 1, the differential pressure control valve according to the present invention includes a housing 2 having at least three ports and a bellows 6 that divides the inside of the housing 2 into two chambers. One of the three ports (reference pressure port) 9 communicates with one chamber 3 defined by the bellows 6, and the other two ports (control pressure port and control pressure port) are communicated with the other chamber 4a. The discharge ports 10 and 11 are in communication.

  One chamber 3 that communicates with the reference pressure port 9 forms a gas chamber that is exclusively opened to a gas such as the atmosphere, and this chamber is referred to as a reference pressure chamber 3. The other chamber 4a communicating with the control pressure port 10 and the discharge port 11 is a fluid chamber formed in a part of a passage connecting the control pressure port 10 and the discharge port 11, and this chamber is used as the control pressure chamber. This is referred to as 4a.

  The bellows 6 is a bellows (bellows) having a base end portion supported by the inner wall of the housing 2 and a distal end portion having flexibility to expand and contract in the coaxial direction with the housing 2. A valve body 7 is fixedly supported at the tip of the bellows 6, and the valve body 7 is displaced in the vertical direction of the drawing as the bellows 6 expands and contracts. Accordingly, the bellows 6 serves as a kind of valve shaft.

  By the way, since the front-end | tip part is obstruct | occluded with the valve body 7, the bellows 6 has sealing performance. Therefore, the reference pressure chamber 3 configured on the inner side of the bellows 6 (upper side of the bellows 6 in the drawing) and the fluid pressure chamber 4a configured on the outer side of the bellows (lower side of the valve body 7 in the drawing) are separated from the bellows 6. Completely isolated by. Therefore, gas such as the atmosphere that has entered from the reference pressure port 9 accumulates in the bellows 6, and this pressure acts in the direction of extending the bellows 6 via the valve body 7. On the other hand, the pressure of the fluid in the control pressure chamber 4 a that has entered from the control pressure port 10 acts in the direction of contracting the bellows 6 via the valve body 7. That is, the pressure acting on the valve body 7 from the reference pressure chamber 3 side and the pressure acting on the valve body 7 from the control pressure chamber 4a side are balanced with a certain differential pressure, and the valve body 7 is held in the balanced position. .

  Thus, according to this differential pressure control valve, the opening degree of the valve is operated in accordance with the pressure of the gas acting on the valve body 7 from the inside of the bellows 6.

  The material of the bellows 6 is often made of phosphor bronze, but is not limited thereto, and may be copper, aluminum bronze, stainless bronze, pure iron, or the like.

  The above is the configuration of the differential pressure control valve according to the present invention. Next, the operation will be described.

  For example, when the reference pressure chamber 3 is opened to the atmosphere via the reference pressure port 9, the taken-in atmosphere enters the bellows 6 via the reference pressure chamber 3. On the other hand, the working fluid that has entered from the control pressure port 10 is discharged from the discharge port 11 via the control pressure chamber 4a. Since the reference pressure chamber 3 and the fluid pressure chamber 4a are completely separated by the bellows 6, the atmospheric pressure that has entered the bellows 6 acts on the valve body 7 from the inside of the bellows 6, and the fluid in the control pressure chamber 4a is It acts on the valve body 7 from the outside of the bellows 6 (control pressure chamber 4a side).

  Accordingly, when the force due to the atmospheric pressure in the reference pressure chamber 3 and the spring force due to the bellows 6 exceed the force due to the fluid pressure in the fluid pressure chamber 4a, the bellows 6 begins to expand, and the valve body 7 descends accordingly (downward in the drawing). To be displaced). On the contrary, when the force by the fluid pressure in the control pressure chamber 4a and the spring force by the bellows 6 exceed the atmospheric pressure of the reference pressure chamber 3, the bellows 6 contracts and the valve body 7 rises (displaces upward in the drawing). . In this manner, the valve body 7 is maintained at a position where the mutual force between the atmospheric pressure and the fluid pressure and the spring force of the bellows 6 are balanced. That is, since the fluid pressure flowing in the control pressure chamber 4a is controlled according to the atmospheric pressure in the reference pressure chamber 3, the atmospheric pressure in the reference pressure chamber 3 functions as a so-called reference (standard) pressure. It will be.

  In the above, the case where the reference pressure chamber 3 is open to the atmosphere has been described. However, the reference pressure chamber 3 does not necessarily have to be open to the atmosphere. You may make it send. In this case, the gas functioning as the reference pressure may be not only air but also gas.

  Thus, since the differential pressure control valve 1 controls the pressure of the fluid according to the reference pressure, the pressure of the working fluid is uniquely determined by the spring characteristics of the bellows 6, and changes in the reference pressure. Accordingly, the fluid pressure can be changed, and the differential pressure between the reference pressure and the fluid pressure can be kept constant. Further, since the stroke range of the valve body 7 can be increased by the characteristics of the bellows 6, the pressure loss is smaller than that of the diaphragm valve, and for example, highly accurate control under a low pressure is possible.

  The embodiment shown in FIG. 2 is provided with a partition wall 5 that supports the bellows 6 and partitions the inside of the housing 2.

  The partition wall 5 is a flat wall that divides the interior of the housing 2 into a reference pressure chamber 3 and a control pressure chamber 4 a, and is fixedly supported or integrally formed with the inner wall of the housing 2 in the housing 2. Further, a hole 5a is formed in the partition wall 5. The hole 5a is covered with a bellows 6 from the control pressure chamber 4a side so that the reference pressure chamber 3 and the inside of the bellows 6 communicate with each other through the hole 5a. It has become. Therefore, the gas in the reference pressure chamber 3 enters the bellows 6 through the hole 5a of the partition wall 5, but the bellows 6 whose end portion is closed (supported by closing) by the valve body 7 is as described above. Due to the sealing property, the reference pressure chamber 3 and the control pressure chamber 4 a are completely separated by the partition wall 5 and the bellows 6.

  The hole 5a formed in the partition wall 5 is formed with a diameter smaller than the inner diameter of the bellows 6. However, if this condition is satisfied, the size of the hole 5a is particularly limited to a specific size. Is not to be done. However, it goes without saying that finer control can be achieved by adjusting the size of the hole 5a according to the use situation or the like. Moreover, the shape of the hole 5a does not need to be limited to, for example, a circle, and may be other shapes such as a rectangle.

  In the embodiment shown in FIG. 3, a valve seat 8 is provided at a position facing the valve body 7 supported at the tip of the bellows 6.

The valve seat 8 is a seat on which the valve body 7 is attached to the inner wall of the housing 2 and is formed so as to project annularly toward the radially inner side of the housing 2. Since the valve seat 8 is provided at a position below the valve body 7 (lower side of the valve body 7 in the drawing) and opposite to the valve body 7, when the bellows 6 is extended and the valve body 7 is lowered, The distance between the body 7 and the valve seat 8 is reduced, and the opening of the valve is closed. On the other hand, when the valve body 7 rises due to the contraction of the bellows 6, the distance between the valve body 7 and the valve seat 8 increases, and the valve opening degree is opened.
In the present embodiment, the valve seat 8 is a flat seat together with the flat plate-like valve body 7, but may be, for example, a conical seat, a spherical seat, an implanted seat, and the like. Various shapes of the valve body 7 are conceivable.

  According to the differential pressure control valve according to the present embodiment, for example, when the atmospheric pressure in the reference pressure chamber 3 exceeds the fluid pressure in the fluid pressure chamber 4a at a certain operating point, the bellows 6 expands, and accordingly, the valve body 7 Descends. When the valve body 7 is lowered, the valve body 7 approaches the valve seat 8 and the flow rate of the fluid discharged from the discharge port 11 is reduced. On the other hand, when the fluid pressure in the fluid pressure chamber 4a exceeds the atmospheric pressure in the reference pressure chamber 3, the bellows 6 contracts and the valve body 7 rises accordingly. When the valve body 7 rises, the valve body 7 moves away from the valve seat 8 and the flow rate of the fluid discharged from the discharge port 11 increases. That is, when the valve body 7 is closed by the expansion of the bellows 6, the fluid pressure in the control pressure chamber 4a formed between the control pressure port 10 and the valve seat 8 rises and the bellows 6 contracts. When the valve body 7 is opened by this, the fluid pressure in the control pressure chamber 4a decreases.

  As described above, in this embodiment, since the valve body 7 is displaced by the expansion and contraction of the bellows 6, the stroke range of the valve body 7 can be increased, and the valve seat is positioned at a position facing the valve body 7. 8 is provided, and the opening degree of the valve is adjusted according to the distance between the valve body 7 and the valve seat 8, so that there is a merit that the degree of freedom in controlling the fluid pressure is greater than that in the above embodiment.

  The embodiment shown in FIG. 4 is provided with a partition wall 5 that partitions the reference pressure chamber 3, the exhaust pressure chamber 4b, and the control pressure chamber 4a.

  The exhaust pressure chamber 4 b is a chamber surrounded by the bellows 6, the valve body 7, and the valve seat 8, and is located just above the control pressure chamber 4 a through the valve seat 8. In this differential pressure control valve, the fluid pressure in the control pressure chamber 4a formed between the control pressure port 10 and the valve seat 8 is controlled by the expansion and contraction of the bellows 6, so that the control pressure chamber 4a is located above the control pressure chamber 4a. The formed exhaust pressure chamber 4b and the control pressure chamber 4a are clearly distinguished in terms of function.

  The partition wall 5 is a flat wall that divides the inside of the housing 2 into a reference pressure chamber 3 and an exhaust pressure chamber 4 b, and is fixedly supported or integrally formed with the inner wall of the housing 2 in the housing 2. Further, a hole 5a is formed in the partition wall 5, and this hole 5a is covered with the bellows 6 from the exhaust pressure chamber 4b side so that the reference pressure chamber 3 and the inside of the bellows 6 communicate with each other through the hole 5a. It has become. Therefore, the gas in the reference pressure chamber 3 enters the bellows 6 through the hole 5a of the partition wall 5, but the bellows 6 whose end portion is blocked by the valve body 7 has a sealing property as described above. The reference pressure chamber 3, the exhaust pressure chamber 4b, and the control pressure chamber 4a are completely separated by the partition wall 5 and the bellows 6.

  Note that the hole 5a formed in the partition wall 5 is formed to have a diameter smaller than the inner diameter of the bellows 6, and if this condition is satisfied, the size of the hole 5a is particularly limited to a specific size. It is the same as above that it is not a thing.

  5 to 10 show an embodiment in which any one of the stroke regulating rods 12a, 12b, 12c, 12d, 12e, and 12f is provided.

  In the embodiment shown in FIG. 5, the base end portion of the stroke regulating rod 12 a is supported by the upper inner wall surface (upward in the drawing) of the housing 2, and the distal end portion passes through the hole 5 a of the partition wall 5 and passes through the bellows 6. 7 (downward in the drawing).

  The stroke regulating rod 12a regulates the contraction range of the bellows 6, and is provided so that the bellows 6 does not contract more than a certain amount. Therefore, for example, when the fluid pressure in the control pressure chamber 4a exceeds the reference pressure, the bellows 6 starts to contract, but when the bellows 6 comes to a certain contraction position, the tip portion of the stroke regulating rod 12a comes into contact with the valve body 7. The bellows 6 does not shrink any further. Therefore, the length of the stroke restricting rod 12a is determined so that the valve body 7 stops at that position when the bellows 6 (valve body 7) reaches a predetermined maximum contracted position.

  With the above configuration, according to this embodiment, for example, even if the bellows 6 contracts, when the bellows 6 comes to a predetermined contraction position, the bellows 6 is not further contracted by the stroke restricting rod 12a. The contraction range (the rising range of the valve body 7) can be regulated.

  By regulating the contraction range of the bellows 6 with the stroke regulating rod 12a, it is possible to prevent buckling, plastic deformation, and the like of the bellows 6, and to improve the responsiveness of the valve.

  FIG. 6 shows an example in which the base end portion of the stroke regulating rod 12b is supported by the upper inner wall surface of the housing 2 and the front end portion penetrates the partition wall 5 and protrudes toward the valve body 7 in the bellows 6. It is.

  Also in this embodiment, when the fluid pressure in the control pressure chamber 4a exceeds the reference pressure at a certain operating point, the bellows 6 begins to contract, but when the bellows 6 reaches a certain contraction position, the tip of the stroke regulating rod 12b. The portion comes into contact with the valve body 7 and the bellows 6 does not contract any more.

  Thereby, buckling, plastic deformation, etc. of the bellows 6 can be prevented and the responsiveness of the valve is improved. Further, since the stroke restricting rod 12b is also supported by the partition wall 5, the support of the stroke restricting rod 12b becomes stronger.

  FIG. 7 shows an example in which the base end portion of the stroke regulating rod 12c is supported by the partition wall 5 and the tip portion projects toward the valve body 7 in the bellows 6. FIG. 8 shows the stroke regulating rod 12d. This shows an example in which the base end portion is supported by the valve body 7 and the tip end portion protrudes toward the partition wall 5 in the bellows 6.

  In any of the embodiments, when the bellows 6 comes to a contracted position, the stroke restricting rod 12c or 12d comes into contact with the valve body 7, and the contraction is restricted, so that the bellows 6 is prevented from buckling or plastic deformation. Of course, the responsiveness of the valve can be improved.

  In the above-described embodiment, the stroke regulating rod 12c or 12d may be plate-shaped instead of rod-shaped.

  Further, the stroke regulating rod 12d applied to the embodiment shown in FIG. 8 can also be applied to the embodiment shown in FIG. 1 or 2 in which the partition wall 5 is not provided. In this case, the stroke restricting rod 12d extends in the bellows 6 toward the upper inner wall surface of the housing 6 instead of the partition wall 5 in the bellows 6.

  FIG. 9 shows an example in which the base end portion of the stroke restricting rod 12e is supported by the partition wall 5, and the tip portion protrudes toward the valve body 7 outside (outer periphery) of the bellows 6. FIG. 10 shows the stroke restricting rod. An example in which the base end portion of 12f is supported by the valve body 7 and the tip portion protrudes toward the partition wall 5 outside (outer periphery) of the bellows 6 is shown.

  In this case, the stroke regulating rod 12e or 12f may be provided with a plurality of rod-like or plate-like ones, or may be a cylindrical one that covers the periphery of the bellows 6 in an annular shape.

  According to these embodiments, when the bellows 6 comes to a certain contraction position, the stroke restricting rod 12e contacts the valve body 7 or the stroke restricting rod 12f contacts the partition wall 5, and the contraction thereof is restricted. 6 can prevent buckling, plastic deformation, and the like, and can improve the responsiveness of the valve. In addition, since a plurality of stroke regulating rods 12e or 12f or an annular stroke regulating rod 12e or 12f are provided around the outer periphery of the bellows 6, the stroke regulating rod 12e or 12f can be improved in durability, Regulation can be performed more reliably.

11 to 14 show an embodiment in which any one of the valve body pins 13a, 13b, 13c, and 13d is provided.
The valve body pins 13a to 13d are for regulating the extension range of the bellows 6 (the descending range of the valve body 7).

  In the embodiment shown in FIG. 11, the base end portion of the valve body pin 13a is supported on the bottom inner wall surface (downward in the drawing) of the housing 2, and the distal end portion is the lower portion of the valve body 7 (the inner side of the bellows 6 of the valve body 7). This is an example in the case of being fitted in a recess 7a formed on the control pressure chamber 4a side).

  The valve body pin 13a is not fitted and fixedly supported in the recess 7a without any gap, but the axial direction (the recess depth direction) and the diameter so that the valve body 7 can move vertically along the valve body pin 13a. It is inserted with a predetermined gap in the direction. That is, the inner diameter of the recess 7a is formed larger than the outer diameter of the valve body pin 13a (a gap is formed between the inner peripheral surface of the recess 7a and the outer peripheral surface of the valve body pin 13a), and the recess 7a. When the valve body 7 descends to the lowest position, the deepest part of the recess 7a and the tip of the valve body pin 13a come into contact with each other (the deepest part of the recess 7a and the tip (top) of the valve body pin 13a). A gap is formed between each other.)

  The valve body pin 13a configured as described above regulates the positioning of the valve body 7, that is, the lowering range of the valve body 7, and the valve body 7 or the bellows 6 is lowered or extended beyond a predetermined position. It is for not to be. Accordingly, the bellows 6 expands and contracts along the valve body pin 13a, and when the bellows 6 contracts to a certain position, the valve body pin 13a and the deepest portion of the recess 7a come into contact with each other so that the bellows 6 does not extend any further. It has become. That is, the length of the valve body pin 13a and the depth of the recess 7a are determined such that when the bellows 6 reaches a predetermined maximum extension position, the valve body pin 13a stops at that position.

  In this way, by restricting the descending range of the valve body 7 by the valve body pin 13a, the bellows 6 expands and contracts along the valve body pin 13a. For example, the valve body is installed sideways. In addition, the bellows 6 can be prevented from tilting (falling down) by its own weight.

  Further, for example, when the differential pressure control valve functions as a bidirectional valve, that is, when a reverse flow in which fluid flows from the discharge port 11 and is discharged to the control pressure port 10 is allowed, It is possible to restrict the body 7 from being completely closed by the valve body pin 13a. In this case, the valve body 7 and the valve body pin 13a are brought into contact with each other before the valve body 7 and the valve seat 8 are closed.

  In the above description, it has been described that a gap is formed in the fitting portion of the valve body recess 7a and the valve body pin 13a. However, as shown in FIG. 16, the control pressure chamber 4a and the exhaust pressure are formed in this gap portion. It is also intended that a part of the fluid flowing through the chamber 4b passes through. That is, when the fluid passes through the gap, the gap produces a so-called damping effect, and gives a certain resistance to the fluid flow. A part of the fluid flows in this gap in the fitting portion between the valve body concave portion 7a and the valve body pin 13a, thereby generating a predetermined damping force, enabling finer control, and suppressing vibrations. Can contribute.

In FIG. 12, the base end portion of the valve body pin 13 b is fixedly supported on the lower portion of the valve body 7, and the distal end portion is slidably movable with the recess 7 b formed on the bottom inner wall surface of the housing 2. is there. Therefore, the valve body pin 13b slides in the recess 7b along the vertical direction of the drawing, and a predetermined damping force is generated in the recess 7b on the bottom surface of the housing 2.
In the case of this embodiment as well, the valve body can be installed sideways in the same manner as in the previous embodiment, and it can be used as a bidirectional valve by adjusting the length of the valve body pin 13b.
In addition, the valve body pin 13a or 13b is not necessarily limited to a rod-like one, and may be, for example, a plate-like one.

  FIG. 13 shows a case where the base end portion of the valve body pin 13c is supported by the valve seat 8 and the distal end portion is fitted into a recess 7c formed in the lower portion of the valve body 7, and FIG. This shows a case where the base end portion is supported by the lower portion of the valve body 7 and the distal end portion is fitted into a recess 7 d formed in the valve seat 8.

  In the embodiment shown in FIG. 13, two or a plurality of rod-like or plate-like valve body pins 13c are supported on the annular valve seat 8, and in the embodiment shown in FIG. A plurality of rod-like or plate-like valve body pins 13 protrude. Instead of using a rod-like or plate-like valve body pin, an annular and cylindrical valve body pin 13c or 13d may be used along the surface of the annular valve seat 8 or the valve body 7. In this case, recesses 7c and 7d formed in the lower part of the valve body 7 and the valve seat 8 are also engraved in an annular shape.

  Also in the above embodiment, a predetermined gap is formed in the fitting portion between the valve body pin 13c or 13d and the recess 7c or 7d, and the valve body 7 slides along the valve body pin 13c or 13d. Damping force is generated in the gap.

  According to this embodiment, the valve body 7 can be supported by a plurality of or annular valve body pins 13c or 13d, so that the rigidity of the apparatus can be improved and the bellows 6 can be reliably extended beyond a predetermined position. Can be prevented.

  FIG. 15 shows an embodiment in which both the stroke regulating rod 12b and the valve body pin 13a are provided.

  According to the figure, the differential pressure control valve according to this embodiment covers the partition wall 5 that partitions the reference pressure chamber 3, the exhaust pressure chamber 4b, and the control pressure chamber 4a, and the hole 5a formed in the partition wall 5. In the differential pressure control valve having a bellows 6 attached to the valve body and a valve seat 8 provided at a position facing the valve body 7 supported at the tip of the bellows 6, the base end portion is supported on the upper inner wall surface of the housing 2 The front end portion penetrates the partition wall 5 and protrudes toward the valve body 7 in the bellows 6, the base end portion is supported by the bottom inner wall surface of the housing 2, and the front end portion is the valve body. 7 is provided with a valve body pin 13a fitted in a recess 7a provided in a lower portion of the valve. The valve body pin 13a is fitted with a predetermined gap in the axial direction (recess depth direction) and the radial direction so that the valve body 7 can move in the vertical direction along the valve body pin 13a. That is, a predetermined gap is formed between the inner peripheral surface of the concave portion 7a and the outer peripheral surface of the valve body pin 13a and between the deepest portion of the concave portion 7a and the distal end portion of the valve body pin 13a.

  With the above configuration, the present embodiment has the following effects.

  For example, when the atmospheric pressure in the reference pressure chamber 3 exceeds the fluid pressure in the control pressure chamber 4a and the bellows 6 begins to expand, the valve body 7 also descends accordingly. When the valve body 7 is lowered to a predetermined position, the valve body pin 13 (the tip portion thereof) and the concave portion 7a of the valve body 7 come into contact with each other, and the lowering of the valve body 7 is restricted. On the other hand, when the fluid pressure in the control pressure chamber 4 exceeds the atmospheric pressure in the reference pressure chamber 3 and the bellows 6 starts to contract, the valve body 7 rises, but when the valve body 7 rises to a certain position, this time, the stroke The restricting rod 12b (the tip portion thereof) and the valve body 7 come into contact with each other, and the ascent of the valve body 7 is restricted. That is, the displacement of the valve body 7 or the expansion / contraction of the bellows 6 is performed within a predetermined range by the stroke regulating rod 12b and the valve body pin 13a.

  In addition, part of the fluid flowing in the control pressure chamber 4a and the exhaust pressure chamber 4b flows into the gap formed in the fitting portion of the valve body 7 and the valve body pin 13a. As in the case of the example, a predetermined damping force is generated in this portion. This enables finer control and contributes to vibration suppression and the like.

  As described above, by providing both the stroke regulating rod 12b and the valve body pin 13a, not only the contraction direction of the bellows 6 but also the extension direction is regulated, and further improvement in response can be expected. The valve body 7 slidably fitted into the body pin 13a can be prevented from coming off.

  In this embodiment, the base end portion of the stroke regulating rod 12b is supported by the upper inner wall surface of the housing 2, and the distal end portion penetrates the partition wall 5 and protrudes inside the bellows 6 toward the valve body 7. Although the case where the base end portion of the valve body pin 13a is supported by the inner wall surface of the bottom portion of the housing 2 and the distal end portion is fitted in the recess 7a provided in the lower portion of the valve body 7 is shown, The stroke restriction rod may be any of the embodiments shown in FIGS. 7 to 10 (stroke restriction rods 12a and 12c to 12f), and the valve pin is also shown in FIGS. Any form (valve body pins 13b to 13d) shown in FIG.

  By providing both the stroke restricting rods 12a to 12f and the valve body pins 13a to 13d, not only the contraction direction but also the expansion direction of the bellows 6 is controlled, and further improvement in responsiveness can be expected. It is also possible to prevent the valve body 7 slidably inserted into the pins 13a to 13d from being removed.

  Although not shown, a spring or the like may be added together with the bellows 6. For example, by providing a spring in the bellows 6 in the expansion and contraction direction of the bellows 6, the settable differential pressure range can be expanded when the differential pressure cannot be set only by the spring constant of the bellows 6. .

  Next, an example in which this differential pressure control valve is applied will be described. Since this differential pressure control valve maintains the differential pressure between the reference pressure and the fluid pressure constant and controls the pressure of the working fluid with high accuracy, for example, a fuel cell system as shown in FIG. Can be applied to.

  FIG. 17 is a schematic configuration diagram of a solid polymer fuel cell system. As shown in the figure, the fuel cell system includes a fuel cell main body 20 in which a plurality of cells (unit cells) in which a polymer electrolyte membrane 23 is disposed between a fuel electrode 21 and an oxidant electrode 22 are stacked, and a fuel cell main body. 20 includes a fuel gas supply system 25 for supplying a fuel gas such as hydrogen, an oxidant gas supply system 26 for supplying an oxidant gas such as air, and a cooling water system 27 for removing heat generated during power generation. The

  With the above configuration, for example, when fuel gas is supplied to the fuel electrode 21, hydrogen ions move from the fuel electrode 21 to the oxidant electrode 22 side in the form of protons, and electrons pass through an external load. It moves to the oxidant electrode 21 side, and the hydrogen ions and electrons move to react with oxygen in the oxidizing gas and produce water. A fuel cell system takes out electric energy generated by such a series of electrochemical reactions and uses it as power.

  By the way, for example, in a fuel cell system for a vehicle having a large load fluctuation, an oxidant gas supply amount is changed according to a required load. For this reason, the cooling amount must be changed according to the supply amount of the oxidant gas. Therefore, as shown in FIG. 17, the cooling water system 27 is provided with the differential pressure control valve 1 to adjust the pressure of the cooling water in the cooling plate 24 in accordance with the oxidant gas pressure.

  Specifically, a part of the oxidant gas from the oxidant gas supply system 27 is taken into the reference pressure chamber 3 through the reference pressure port 9, and the cooling water from the cooling plate 24 is supplied to the differential pressure control valve. 1 (passed from the control pressure port 10 and discharged from the discharge port 11). The cooling water that has passed through the differential pressure control valve 1 is guided into the tank 28.

  With the above configuration, for example, when the oxidant gas supply amount (oxidant gas pressure) increases, the bellows 6 in the differential pressure control valve 1 expands, and the valve opening degree of the differential pressure control bubble 1 is closed. When the valve opening is closed, the fluid pressure in the control pressure chamber 4a, that is, the pressure of the cooling water increases, and the amount of cooling due to, for example, latent heat of evaporation (heat taken from the fuel cell body when water evaporates) increases. .

  On the other hand, when the air supply amount decreases, this time, the valve opening degree of the differential pressure control valve 1 acts to open the fluid pressure in the control pressure chamber 4a, that is, the pressure of the cooling water, for example, latent heat of evaporation. The amount of cooling due to is also reduced.

  In this way, by applying the differential pressure control valve 1, the pressure of the cooling water can be adjusted according to the supply amount of the oxidant gas, and the cooling amount can be controlled.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  The differential pressure control valve of the present invention can be applied to the fuel cell system, and is not limited to this, and can also be used for other devices that operate the opening of the valve in accordance with the gas pressure.

1 is a schematic cross-sectional view of a differential pressure control valve according to the present invention. It is an Example when a partition is provided. It is an Example at the time of providing a valve seat. It is an Example at the time of providing a partition and a valve seat. It is an Example at the time of providing a stroke control rod. Similarly, it is an embodiment when a stroke regulating rod is provided. Similarly, it is an embodiment when a stroke regulating rod is provided. Similarly, it is an embodiment when a stroke regulating rod is provided. Similarly, it is an embodiment when a stroke regulating rod is provided. Similarly, it is an embodiment when a stroke regulating rod is provided. It is an Example at the time of providing a valve body pin. Similarly, it is an embodiment when a valve body pin is provided. Similarly, it is an embodiment when a valve body pin is provided. Similarly, it is an embodiment when a valve body pin is provided. This is an embodiment in which both a stroke regulating rod and a valve body pin are provided. It is an enlarged view of the insertion part of a valve body pin and a valve body recessed part. It is a schematic block diagram of the fuel cell system to which this differential pressure control valve was applied. It is a schematic sectional drawing of the diaphragm valve which concerns on a prior art example. It is a block diagram at the time of applying a diaphragm valve to a toilet tank.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Differential pressure control valve 2 Housing 3 Reference pressure chamber 4a Control pressure chamber 4b Exhaust pressure chamber 5 Partition 5a Hole 6 Bellows 7 Valve body 7a-7d Recessed part 8 Valve seat 9 Reference pressure port 10 Control pressure port 11 Exhaust port 12a-12f Stroke Regulating rod 13a-13d Valve body pin

Claims (14)

A housing having a reference pressure port, a control pressure port, and a discharge port;
A bellows that divides the housing into a reference pressure chamber that communicates with the reference pressure port and a control pressure chamber that is configured as a part of a passage that connects the control pressure port and the discharge port;
A differential pressure control valve having a valve body supported at a tip of the bellows. A partition partitioning the inside of the housing;
Holes formed in the partition;
A bellows supported by the partition;
The bellows is attached to the partition so as to cover the hole,
The differential pressure control valve according to claim 1, wherein the differential pressure control valve is configured to expand and contract in a direction coaxial with the housing toward the control pressure chamber. A valve seat is provided inside the housing at a position facing the valve body,
The pressure in a control pressure chamber formed between the control pressure port and the valve seat is controlled by contacting and separating the valve body and the valve seat. The differential pressure control valve. A partition partitioning the inside of the housing;
Holes formed in the partition;
A bellows supported by the partition;
The bellows is attached to the partition so as to cover the hole,
3. The difference according to claim 2, wherein in the exhaust pressure chamber surrounded by the bellows, the valve body, and the valve seat, the difference is configured to expand and contract in a direction coaxial with the housing toward the control pressure chamber. Pressure control valve.   The base end portion is supported by the inner wall surface of the upper part of the housing, and a stroke restricting rod that protrudes toward the valve body in the bellows at the distal end side is provided. Differential pressure control valve described in 1.   The base end portion is supported by the inner wall surface of the upper part of the housing, and a stroke restricting rod is provided that protrudes in the direction of the valve body in the bellows through the partition wall. Alternatively, the differential pressure control valve according to claim 4.   5. The differential pressure according to claim 3, wherein a base end portion is supported by the partition wall, and a stroke restricting rod that protrudes toward the valve body in the bellows at a distal end side is provided. Control valve.   5. The stroke regulating rod according to claim 1, wherein a base end portion is supported by the valve body and a distal end side thereof is provided in the bellows so as to protrude toward the upper portion of the housing or the partition wall. Differential pressure control valve described in 1.   The base end portion is supported by the partition wall, and the front end side is an outer periphery of the bellows, and a stroke restricting rod that protrudes toward the valve body is provided. The differential pressure control valve.   The base end portion is supported by the valve body, and the front end side is an outer periphery of the bellows, and a stroke restricting rod that protrudes toward the upper portion of the housing or the partition wall is provided. The differential pressure control valve according to any one of the above.   A base end portion is supported on the inner wall surface of the bottom portion of the housing, and a valve body pin is provided that fits into a recess formed on a lower end side of the valve body, and an inner peripheral surface of the recess and an outer peripheral surface of the valve body pin And a predetermined gap between the deepest part of the recess and the tip of the valve body pin, the valve body slides along the valve body pin, and a predetermined gap is formed in the gap. The differential pressure control valve according to any one of claims 1 to 10, wherein a fluid flows.   A base end portion is supported by the valve body, and a distal end side is provided with a valve body pin that fits into a recess formed in the inner wall surface of the bottom of the housing, and an inner peripheral surface of the recess and an outer peripheral surface of the valve body pin By forming a predetermined gap between the deepest part of the recess and the tip of the valve body pin, the valve body pin supported by the valve body slides in the recess, and this The differential pressure control valve according to any one of claims 1 to 10, wherein a predetermined fluid flows in the gap.   A base end portion is supported by the valve seat, and a valve body pin that fits into a concave portion formed at a lower end of the valve body is provided on the distal end side, and is provided between the inner peripheral surface of the concave portion and the outer peripheral surface of the valve body pin. And by forming a predetermined gap between the deepest part of the recess and the tip of the valve body pin, the valve body slides along the valve body pin, and a predetermined fluid flows into the gap. 11. The differential pressure control valve according to claim 2, wherein the differential pressure control valve is configured to flow.   A base end portion is supported by the valve body, and a valve body pin that fits into a recess formed in the valve seat on the distal end side is provided, and between the inner peripheral surface of the recess and the outer peripheral surface of the valve body pin and the By forming a predetermined gap between the deepest part of the recess and the tip of the valve body pin, the valve body pin supported by the valve body slides in the recess, and a predetermined gap is formed in the gap. The differential pressure control valve according to any one of claims 2 and 3 to 10, characterized in that the fluid of the above is flowed.

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