JP2007292278A - Equal differential pressure control pilot valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an equal differential pressure control pilot valve capable of controlling the secondary pressure of a control valve so that differential pressure with fluid pressure is constant by sensing the pressure of the fluid flowing in a passage of the other system. <P>SOLUTION: A valve element 22 is disposed in a main body 1 so as to be approachable to and separable from a valve seat 21, a diaphragm 5 is disposed in the main body 1 so as to partition an operation chamber to a first operation chamber 6 and a second operation chamber 7 in the approaching and separating direction of the valve element 22 to the valve seat 21, and a spring 27 is disposed so as to energize the diaphragm 5 in the direction of separating the valve element from the valve seat 21. A second shaft 31 is disposed so as to transmit the displacement of the diaphragm 5 to the valve element 22. Reference pressure is introduced into the first operation chamber 6 through a reference fluid connection port 8, and pressure regulation pressure is introduced into the second operation chamber 7 through a secondary-side connection port 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an equal differential pressure control pilot valve applied to, for example, a foam mixing device that mixes fire-extinguishing water and foam stock solution at a predetermined mixing ratio.

  The conventional pilot valve that controls the secondary pressure of the pressure regulating valve senses the pressure on the secondary side of the pressure regulating valve, and controls the opening of the pressure regulating valve based on the differential pressure between the pressure and the spring force of the pilot valve. (For example, refer to Patent Document 1).

JP-A-6-241334

In the conventional pilot valve, the secondary pressure of the pressure regulating valve can be regulated to the spring force, and further, the secondary pressure of the pressure regulating valve can be adjusted by adjusting the spring force.
However, since the conventional pilot valve cannot sense the pressure of the fluid flowing in the flow path of the other system, for example, for an application in which the differential pressure of the fluid flowing in the flow path of the two systems is constant, A pair of conventional pilot valves is arranged in each of the two flow paths, and the spring force of each conventional pilot valve is adjusted so that a desired differential pressure is obtained. Had to be adjusted to the adjusted spring force.

  The present invention has been made to solve the above-described problem, and is capable of sensing the pressure of a fluid flowing in a flow path of another system so that the differential pressure with respect to the fluid pressure is constant. An object of the present invention is to obtain an equal differential pressure control pilot valve capable of adjusting the secondary pressure.

  An equal differential pressure control pilot valve according to the present invention includes a valve device having a main valve disposed so as to be able to contact with and separate from a valve seat that partitions an inlet and an outlet, and the main valve with respect to the valve seat in an axial direction. An operation chamber having a contact / separation direction between the first operation chamber and the first operation chamber in which the reference pressure is introduced in the axial direction in the operation chamber and a pressure regulation pressure. A partition member defined in the second operation chamber to be introduced; urging means for urging pressure on the partition member in the axial direction; and transmitting the axial displacement of the partition member to the main valve. And a power transmission member for bringing the main valve into and out of contact with the valve seat.

  According to this invention, the reference pressure introduced into the first operation chamber, the pressure regulation pressure introduced into the second operation chamber, and the pressure urged by the urging means act on the partition member. The partition member is displaced according to the magnitude relationship between the differential pressure between the reference pressure and the regulated pressure and the pressure urged by the urging means. The displacement of the partition member is transmitted to the valve device by the power transmission member, and the valve device is opened and closed. Therefore, if the control fluid supply path of the control valve is opened and closed by the valve device, the secondary pressure of the control valve is used as the regulated pressure, and the pressure of the fluid flowing through the flow path of the other system is used as the reference pressure, the flow of the other system Even if the pressure of the fluid flowing through the passage fluctuates, the secondary pressure of the control valve can be adjusted so that the differential pressure from the pressure of the fluid becomes the pressure by the urging means.

Embodiment 1 FIG.
1 is a cross-sectional view showing an open state of an equal differential pressure control pilot valve according to Embodiment 1 of the present invention, and FIG. 1 (b) is a cross section in a plane orthogonal to FIG. 1 (a). The figure is shown. FIG. 2 is a sectional view showing a closed state of the equal differential pressure control pilot valve according to the first embodiment of the present invention, and FIG. 3 is a bubble mixing to which the equal differential pressure control pilot valve according to the first embodiment of the present invention is applied. FIG. 4 is a cross-sectional view showing the closed state of the control valve in the foam mixing apparatus shown in FIG. 3, and FIG. 5 is a schematic view of the control valve in the foam mixing apparatus shown in FIG. It is sectional drawing which shows a valve opening state.

  In FIG. 1, a main body 1 is configured by fastening a first divided body 2 and a second divided body 3, and an operation chamber is formed inside. A diaphragm 5 as a partition member held by the diaphragm presser 4 is sandwiched between the first divided body 2 and the second divided body 3, and the first operation chamber 6 and the second operation chamber are axially arranged in the operation chamber. 7 is attached to the inside of the main body 1 so as to be defined.

  The first operation chamber 6 is defined in the first divided body 2 by the diaphragm 5. A reference fluid connection port 8 is formed in the first divided body 2. And the through-hole 9 is formed in the 1st division body 2 so that the 1st operation chamber 6 and the reference | standard fluid connection port 8 may be connected.

  The second operation chamber 7 is defined in the second divided body 3 by the diaphragm 5. Further, the second divided body 3 has connection ports in four directions, that is, a primary side connection port 10, a secondary side connection port 11, a cylinder connection port 12, and a closed connection port 13 sealed by a plug 14. ,have. And the through-hole 15 is formed in the 2nd division body 3 so that the 2nd operation chamber 7 and the secondary side connection port 11 may be connected. Further, the through hole 16 is formed in the second divided body 3 so as to communicate the cylinder connection port 12 and the closed connection port 13.

  A valve chamber 17 is formed inside the second divided body 3. The valve chamber 17 communicates with the primary side connection port 10 through the through hole 18, and communicates with the through hole 16 that communicates the cylinder connection port 12 and the closed connection port 13 through the through hole 19. . The valve chamber 17 is provided with a valve body 22 as a main valve that is seated on the valve seat 21 at the opening edge of the through hole 19 by the biasing force of the spring 20. Here, the valve chamber 17, the primary side connection port 10, the through holes 16, 18, 19, the cylinder connection port 12, the valve seat 21 and the valve body 22 constitute a valve device. The primary side connection port 10 corresponds to an inflow port, and the cylinder connection port 12 corresponds to an outflow port.

  The case 23 has a bottomed cylindrical shape, and is fastened and fixed to the first divided body 2 with the opening facing the first divided body 2. The piston 24 is slidably disposed in a recess 25 that is recessed on the case 23 side of the first divided body 2. A spring receiver 26 is disposed in the case 23 so as to face the piston 24, and a spring 27 is contracted between the piston 24 and the spring receiver 26. The adjustment screw 28 is screwed onto the head of the case 23, and the tip of the adjustment screw 28 presses the spring receiver 26 to adjust the spring pressure. The adjustment screw 28 is fixed by a nut 29. Further, the first shaft 30 is disposed so that one end is fixed to the diaphragm retainer 4, the first divided body 2 is inserted, and the tip thereof is in contact with the piston 24. Here, the adjusting screw 28, the spring receiver 26, the spring 27, the piston 24, and the first shaft 30 constitute an urging means.

A second shaft 31 as a power transmission member is disposed so that one end thereof is fixed to the valve body 22, passes through the through hole 19, is inserted through the second divided body 3, and the tip thereof is in contact with the diaphragm holder 4. ing.
Note that an O-ring is interposed in the insertion portion of the first divided body 2 of the first shaft 30 to prevent fluid leakage, and the first shaft 30 is slidable. In addition, a minute gap is formed in the insertion portion of the second divided body 3 of the second shaft 31 so that the second shaft 31 can move in the axial direction. Further, the first shaft 30 and the second shaft 31 are arranged coaxially. The urging direction of the spring 27 to the diaphragm 5, the displacement direction of the diaphragm 5, and the contact / separation direction of the valve body 22 with respect to the valve seat 21 are the axial directions of the first shaft 30 and the second shaft 31, that is, the axis of the operation chamber. Match the direction.

The operation of the equal differential pressure control pilot valve 100 configured as described above will be described. Here, the pressure (reference pressure) in the first operation chamber 6 is P3, the pressure (pressure regulation pressure) in the second operation chamber 7 is P2, and the spring pressure (biasing force) by the spring 27 adjusted by the adjusting screw 28 is set. Let α be.
First, the spring pressure α by the spring 27 acts so as to press the diaphragm 5 downward in FIG. 1 via the piston 24 and the first shaft 30. Further, the pressure in the first operation chamber 6 acts so as to press the diaphragm 5 downward in FIG. On the other hand, the pressure in the second operation chamber 7 acts to press the diaphragm 5 upward in FIG.

Therefore, when P3 + α> P2, as shown in FIGS. 1A and 1B, the diaphragm 5 is displaced downward. A downward displacement force of the diaphragm 5 is transmitted to the valve body 22 via the second shaft 31, and the valve body 22 descends against the urging force of the spring 20. Thereby, the valve body 22 is separated from the valve seat 21, and the primary side connection port 10 and the cylinder connection port 12 are communicated with each other. At the same time, the spring 20 contracts and accumulates a repulsive force.
When P3 + α ≦ P2, the diaphragm 5 is displaced upward as shown in FIG. Therefore, the repulsive force of the spring 20 is released, and the second shaft 31 and the valve body 22 rise. As a result, the valve body 22 is seated on the valve seat 21 and communication between the primary side connection port 10 and the cylinder connection port 12 is blocked. The seating state of the valve element 22 on the valve seat 21 is maintained by the urging force of the spring 20.

In the equal differential pressure control pilot valve 100 configured as described above, the height position of the spring receiver 26 can be changed by loosening the nut 29 and changing the extension amount of the adjusting screw 28 into the case 23. Thereby, the length of the spring 27 is changed, and the spring pressure α is adjusted. That is, the differential pressure between P2 and P3 is adjusted.
Further, by combining this equal differential pressure control pilot valve 100 and a control valve 200, which will be described later, the control valve 200 is controlled so that the differential pressure with respect to the pressure in the first operation chamber 6 (reference pressure) becomes constant. The next pressure can be adjusted.

  Next, the effect of the equal differential pressure control pilot valve 100 will be described using the foam mixing device shown in FIG.

  In FIG. 3, the foam mixing device includes a mixer 43 that mixes the fire-extinguishing water 41 and the foam stock solution 42, and a fire-extinguishing pump 46 that pumps the fire-extinguishing water 41 in the fire-extinguishing water tank 44 to the mixer 43 via the water supply pipe 45. A foam stock solution pump 50 that pumps the foam stock solution 42 in the foam stock solution tank 47 to the mixer 43 via the primary side foam stock solution pipe 48 and the secondary side foam stock solution pipe 49, the primary side foam stock solution pipe 48, and the secondary The control valve is interposed between the side foam stock solution pipe 49 and adjusts the flow rate of the foam stock solution 42 flowing from the primary side foam stock solution pipe 48 to the secondary side foam stock solution pipe 49 by changing the opening degree of the main valve 67. 200, the primary valve foam solution 42 is supplied to the control valve 200 and the control valve 200 is started to activate the control valve 200, and the main pressure is controlled so that the differential pressure between the fire extinguishing water 41 and the secondary foam solution 42 is constant. An equal differential pressure control pilot that controls the opening degree of the valve 67 to a set opening degree Is provided with a valve 100, a. The foam stock solution 42 is supplied into the mixer 43 from a radiation nozzle 52 attached to the secondary side foam stock solution pipe 49.

Next, the structure of the control valve 200 will be described with reference to FIGS. 4 and 5 indicate the flow of the foam stock solution 2.
The valve body 61 includes a primary side flow path 62 to which the primary side foam stock solution pipe 48 is connected, a secondary side flow path 63 to which the secondary side foam stock solution pipe 49 is connected, a primary side flow path 62 and a secondary side. A communication hole 64 that communicates with the flow path 63, and a cylinder chamber 65 that is formed opposite to the communication hole 64 with the axis aligned with the hole center of the communication hole 64 and with the secondary side flow path 63 interposed therebetween. And. A valve seat 66 is fitted into the communication hole 64.

  The main valve 67 includes a disc portion 68, a plurality of guide portions 69 extending in the axial direction of the main valve 67 at an equiangular pitch in the circumferential direction from the vicinity of one edge of the disc portion 68, and the disc portion 68, and an O-ring 70 disposed on one outer peripheral edge portion. The main valve 67 is slidably mounted by inserting the guide portion 69 into the communication hole 64 from the primary channel 62 side.

  One end of the valve rod 71 is fixed to the other central portion of the disc portion 68 of the valve body 67, and the other side is slidably inserted into a receiving member 73 attached to the lid body 72. The lid 72 is attached to the valve main body 61 so as to close an opening formed opposite to the communication hole 64 with the primary channel 62 interposed therebetween and to prevent fluid leakage. The receiving member 73 is inserted through the lid 72 so as to prevent fluid leakage, and the valve stem 71 is inserted through the receiving member 73 so as to prevent fluid leakage. A spring 74 is contracted between the lid 72 and the disc portion 68 of the main valve 67 to press the disc portion 68 toward the secondary channel 63. As a result, the O-ring 70 is in close contact with the valve seat 66.

  The piston 75 is slidably mounted in the cylinder chamber 65 so as to define the inside of the cylinder chamber 65 into a piston chamber 65a on the secondary flow path side and a working chamber 65b on the anti-secondary flow path side. Then, one end of the connecting rod 76 is fixed to the center position of the piston 75, and a receiving member 77 attached to a partition wall between the secondary side flow path 63 and the cylinder chamber 65 is slidably inserted. The end is fixed to the central portion on one side of the disc portion 68 of the valve body 67. Further, a communication hole 78 is formed in the partition wall between the secondary side flow path 63 and the cylinder chamber 65 so as to communicate the secondary side flow path 63 and the piston chamber 65a, and the inflow / outlet 79 is provided in the working chamber 65b. The valve body 61 is drilled to communicate with the outside. The receiving member 77 is inserted into the partition wall so as to prevent fluid leakage, and the connecting rod 76 is inserted through the receiving member 77 so as to prevent fluid leakage.

In the control valve 200 configured as described above, when the pressurized fluid is not supplied from the inlet / outlet 79 to the working chamber 65 b, the main valve 67 is moved downward in FIG. Then, the O-ring 70 of the main valve 67 is pressed against the valve seat 66 of the communication hole 64, and the flow path between the primary side flow path 62 and the secondary side flow path 63 is blocked.
Further, when the pressurized fluid is supplied from the inflow / outflow port 79 to the working chamber 65 b, the piston 75 is moved upward in FIG. 4 against the urging force of the spring 74. Then, the O-ring 70 of the main valve 67 is separated from the valve seat 66 of the communication hole 64, and the flow path between the primary flow path 62 and the secondary flow path 63 is opened as shown in FIG. The

  Here, the first pipe 55 is disposed so as to communicate with the primary side foam stock solution pipe 48 and the primary side connection port 10 of the equal differential pressure control pilot valve 100, and the motor valve 51 is disposed in the path of the first pipe 55. It is arranged. A second pipe 56 is disposed so as to communicate the secondary side foam stock solution pipe 49 and the secondary side connection port 11 of the equal differential pressure control pilot valve 100. The third pipe 57 is disposed so as to communicate the inflow / outlet 79 of the control valve 200 with the cylinder connection port 12 of the equal differential pressure control pilot valve 100. Further, the fourth pipe 58 is disposed so as to communicate the water supply pipe 45 and the reference fluid connection port 8 of the equal differential pressure control pilot valve 100.

Next, the operation of the foam mixing apparatus configured as described above will be described.
First, when the motor valve 51 is actuated, the foam stock solution 42 in the primary side foam stock solution pipe 48 is controlled via the first pipe 55 from the primary side connection port 10 of the equal differential pressure control pilot valve 100 into the valve chamber 17. It flows in as 200 working fluids. Further, the fire extinguishing water 41 (pressure P3) in the water supply pipe 45 flows into the first operation chamber 6 from the reference fluid connection port 8 through the fourth pipe 58. At this time, since the control valve 200 is closed, the foam stock solution 42 does not flow into the secondary foam stock solution pipe 49. Therefore, P3 + α> P2, and the primary side connection port 10 and the cylinder connection port 12 communicate with each other. As a result, the foam stock solution 42 flows into the working chamber 65 b from the inlet / outlet 79 of the control valve 200 via the third pipe 57. When the foam stock solution 42 is filled in the working chamber 65b, the piston 75 is raised, the main valve 67 is separated from the valve seat 66, and the flow between the primary side flow path 62 and the secondary side flow path 63 is increased. The road is opened. At this time, the foam stock solution 42 in the piston chamber 65 a flows out through the opening 78 into the secondary side flow path 63. Therefore, the foam stock solution 42 flows from the primary side foam stock solution pipe 48 through the control valve 200 into the secondary side foam stock solution pipe 49, and the pressure of the foam stock solution 42 in the secondary side foam stock solution pipe 49 increases.

  When the pressure of the foam concentrate 42 in the secondary foam concentrate pipe 49 increases, the pressure in the second operation chamber 7 of the equal differential pressure control pilot valve 100 increases. When P3 + α ≦ P2, the valve body 22 is seated on the valve seat 21, and the communication between the primary side connection port 10 and the cylinder connection port 12 is blocked. Thereby, the supply of the foam stock solution 42 into the working chamber 65b is stopped. Therefore, the urging force of the spring 74 acts on the foam stock solution 42 in the working chamber 65 b via the piston 75. Thereby, the foam concentrate 42 in the working chamber 65 b passes through the third pipe 57, the cylinder connection port 12, and the through holes 16 and 19, from a minute gap in the insertion portion of the second shaft 31 with the second divided body 3. It gradually flows into the second operation chamber 7 and escapes to the second pipe 56 through the through hole 15 and the secondary side connection port 11. Therefore, the pressure in the working chamber 65b is reduced, the piston 75 is lowered, and the cross-sectional area of the flow path between the primary flow path 62 and the secondary flow path 63 is reduced, that is, the opening degree of the control valve 200. Becomes smaller. Therefore, the flow rate of the foam concentrate 42 flowing from the primary foam concentrate pipe 48 through the control valve 200 to the secondary foam concentrate pipe 49 decreases, and the pressure of the foam concentrate 42 in the secondary foam concentrate pipe 49 decreases. To do.

  Subsequently, when the pressure of the foam stock solution 42 in the secondary side foam stock solution pipe 49 is reduced and the pressure in the second operation chamber 7 of the equal differential pressure control pilot valve 100 is reduced to P3 + α> P2, the valve element 22 is obtained. Is separated from the valve seat 21, and the primary side connection port 10 and the cylinder connection port 12 are communicated with each other. Then, the raw foam solution 42 flows into the working chamber 65b, the pressure in the working chamber 65b increases, and the opening degree of the control valve 200 increases.

This operation is repeated, and the pressure P2 of the foam raw solution 42 in the secondary side foam raw solution pipe 49 is adjusted to a pressure that is larger than the pressure P3 of the fire-extinguishing water 41 in the water supply pipe 45 by α. That is, the differential pressure ΔP between the pressure P2 of the foam concentrate 42 in the secondary side foam concentrate pipe 49 and the pressure P3 of the fire-extinguishing water 41 in the water supply pipe 45 is controlled to be constant.
Then, the fire extinguishing water 41 having the pressure P3 is pumped to the mixer 43 through the water supply pipe 45. On the other hand, the foam stock solution 42 is pressure-regulated to a constant pressure ΔP with respect to the pressure P 3, and is pumped to the mixer 43 through the secondary side foam stock solution pipe 49. Then, the fire-extinguishing water 41 and the foam stock solution 42 are mixed in the mixer 43 to obtain a foam aqueous solution having a predetermined mixing ratio.

In this foam mixing apparatus, the effect of making the pressure difference ΔP between P2 and P3 constant will be described.
First, it is assumed that fire extinguishing water 41 having a pressure (P3) of 1 MPa and a flow rate (Q) of 10,000 L / min is discharged from the fire pump 46. When the pressure fluctuates, the flow rate changes based on Q = k · P ^1/2 (where k is a flow coefficient).
That is, when P3 = 0.9 MPa, Q = 9487 L / min, when P3 = 0.8 MPa, Q = 8944 L / min, and when P3 = 0.7 MPa, Q = 8367 L / min. .

Here, for example, when the differential pressure ΔP is 0.05 MPa, it is assumed that the flow rate of the foam stock solution 42 flowing through the control valve 200 is always controlled to be 101 L / min.
Therefore, when P3 is 1 MPa, the mixing ratio A = {101 / (10000 + 101)} × 100 = 1% of the water for fire extinguishing and the foam stock solution.
When P3 is 0.9 MPa, A = {101 / (9487 + 101)} × 100 = 1.053%, and when P3 is 0.8 MPa, A = {101 / (8944 + 101)} × 100 = When P3 is 0.7 MPa, A = {101 / (8367 + 101)} × 100 = 1.193%.
Thus, it can be seen that even when the pressure P3 of the fire-extinguishing water 41 varies greatly, the mixing ratio of the fire-extinguishing water 41 and the foam stock solution 42 is maintained substantially constant. This change in the mixing ratio has no problem in fire fighting operation.

Thus, the equal differential pressure control pilot valve 100 senses the pressure (reference pressure) P3 of the fire-extinguishing water 41 in the water supply pipe 45, and converts the secondary pressure (pressure regulation pressure) P2 of the control valve 200 to the pressure P3. The pressure is regulated so that the differential pressure ΔP is constant. Therefore, even if the pressure P3 of the fire fighting water 41 changes, the pressure P2 of the foam concentrate 42 in the secondary side foam concentrate pipe 49 changes following the change of the pressure P3, and the differential pressure ΔP becomes constant. A foam aqueous solution in which the fire-extinguishing water 41 and the foam stock solution 42 are always mixed at a predetermined mixing ratio is obtained.
Therefore, by using the equal differential pressure control pilot valve 100, there is no need to install the control valve and the pilot valve in the path of the water supply pipe 45, and the differential pressure ΔP between the fire extinguishing water 41 and the foam stock solution 42 is kept constant. Can be realized with a simple configuration.

Embodiment 2. FIG.
6 is a cross-sectional view showing an open state of an equal differential pressure control pilot valve according to Embodiment 2 of the present invention, and FIG. 6 (b) is a cross section in a plane orthogonal to FIG. 6 (a). The figure is shown. FIG. 7 is a sectional view showing a closed state of the equal differential pressure control pilot valve according to the second embodiment of the present invention.

  In FIG. 6, the main body 1 </ b> A is configured by fastening a first divided body 2 </ b> A and a second divided body 3. A diaphragm 5 as a partition member held by the diaphragm presser 4 is sandwiched between the first divided body 2A and the second divided body 3 and attached in the main body 1A. Furthermore, a bottomed cylindrical case 23A is fastened and fixed to the first divided body 2A with the opening directed to the first divided body 2A. Thereby, the adjustment chamber formed by the main body 1A and the case 23A is defined by the diaphragm 5 in the first operation chamber 6A and the second operation chamber 7 in the axial direction.

  The first operation chamber 6A is defined by the diaphragm 5 in the first divided body 2A and the case 23A. A reference fluid connection port 8 is formed in the first divided body 2A. And the through-hole 9 is formed in the 1st division body 2A so that 6A of 1st operation chambers and the reference | standard fluid connection port 8 may be connected.

  The second operation chamber 7 is defined in the second divided body 3 by the diaphragm 5. Further, the second divided body 3 has connection ports in four directions, that is, a primary side connection port 10, a secondary side connection port 11, a cylinder connection port 12, and a closed connection port 13 sealed by a plug 14. ,have. And the through-hole 15 is formed in the 2nd division body 3 so that the 2nd operation chamber 7 and the secondary side connection port 11 may be connected. Further, the through hole 16 is formed in the second divided body 3 so as to communicate the cylinder connection port 12 and the closed connection port 13.

  A valve chamber 17 is formed in the second divided body 3, and a cover 32 is attached to the second divided body 3 so as to close the valve chamber 17. The valve chamber 17 communicates with the primary side connection port 10 through the through hole 18, and communicates with the through hole 16 that communicates the cylinder connection port 12 and the closed connection port 13 through the through hole 19. . The valve chamber 17 is provided with a valve body 22 </ b> A as a main valve that is seated on the valve seat 21 at the opening edge of the through hole 19 by the biasing force of the spring 20. Here, the valve chamber 17, the primary side connection port 10, the through holes 16, 18, and 19, the cylinder connection port 12, the valve seat 21, and the valve body 22A constitute a valve device. The primary side connection port 10 corresponds to an inflow port, and the cylinder connection port 12 corresponds to an outflow port.

  The spring receiving guide hole 33 is recessed on the head side of the case 23A so that the hole direction coincides with the axial center of the case 23A and opens to the first operation chamber 6A. The spring receiver 26A is slidably disposed in the spring receiver guide hole 33 so as to face the diaphragm retainer 4, and the spring 27 is contracted between the diaphragm retainer 4 and the spring receiver 26A. The adjustment screw 28 is screwed onto the head of the case 23A, and the tip of the adjustment screw 28 presses the spring receiver 26A to adjust the spring pressure. The adjustment screw 28 is fixed by a nut 29. Here, the adjusting screw 28, the spring receiver 26A, and the spring 27 constitute an urging means.

A second shaft 31A as a power transmission member is arranged so that one end thereof is fixed to the surface of the valve body 22A, passes through the through hole 19, is inserted through the second divided body 3, and the tip thereof is in contact with the diaphragm retainer 4. It is installed. Note that the second shaft 31A may be made as a single body with the valve body 22A.
The first through hole 34 is formed on one end side of the second shaft 31A with the hole direction orthogonal to the axial direction of the second shaft 31A. Further, the second through hole 35 makes the hole direction coincide with the axial direction of the second shaft 31A, and communicates the second through hole 35 and the outside of the back surface of the valve element 22A at the axial center position of the second shaft 31A. It is formed as follows.

  Note that a minute gap is formed in the insertion portion of the second divided body 3 of the second shaft 31A, and the second shaft 31A is movable in the axial direction. The urging direction of the spring 27 to the diaphragm 5, the displacement direction of the diaphragm 5, and the contact / separation direction of the valve body 22A with respect to the valve seat 21 coincide with the axial direction of the second shaft 31A, that is, the axial direction of the operation chamber. Yes.

The operation of the equal differential pressure control pilot valve 101 configured as described above will be described. Here, as in the first embodiment, the pressure (reference pressure) in the first operation chamber 6A is P3, the pressure (pressure regulation pressure) in the second operation chamber 7 is P2, and the spring is adjusted by the adjusting screw 28. The spring pressure (biasing force) by 27 is defined as α.
First, the spring pressure α by the spring 27 acts to press the diaphragm 5 downward in FIG. Further, the pressure in the first operation chamber 6A acts to press the diaphragm 5 downward in FIG. On the other hand, the pressure in the second operation chamber 7 acts to press the diaphragm 5 upward in FIG.

Therefore, when P3 + α> P2, as shown in FIGS. 6A and 6B, the diaphragm 5 is displaced downward. The downward displacement force of the diaphragm 5 is transmitted to the valve body 22A via the second shaft 31A, and the valve body 22A descends against the biasing force of the spring 20. Thereby, the valve body 22A is separated from the valve seat 21, and the primary side connection port 10 and the cylinder connection port 12 are communicated. At the same time, the spring 20 contracts and accumulates a repulsive force.
When P3 + α ≦ P2, the diaphragm 5 is displaced upward as shown in FIG. Therefore, the repulsive force of the spring 20 is released, and the second shaft 31A and the valve body 22A rise. Thereby, the valve body 22A is seated on the valve seat 21, and the communication between the primary side connection port 10 and the cylinder connection port 12 is blocked. The seating state of the valve body 22A on the valve seat 21 is maintained by the urging force of the spring 20.

  In the differential pressure control pilot valve 101 configured as described above, the height position of the spring receiver 26A can be changed by loosening the nut 29 and changing the amount of extension of the adjusting screw 28 into the case 23. Thereby, the length of the spring 27 is changed, and the spring pressure α is adjusted. That is, the differential pressure between P2 and P3 is adjusted.

Further, by combining this equal differential pressure control pilot valve 101 with the control valve 200 in place of the equal differential pressure control pilot valve 100, the differential pressure with respect to the pressure (reference pressure) in the first operation chamber 6A becomes constant. In addition, the secondary pressure of the control valve 200 can be regulated.
Therefore, if this equal differential pressure control pilot valve 101 is applied to a foam mixing device instead of the equal differential pressure control pilot valve 100, the same effect as in the first embodiment can be obtained. That is, even if the pressure P3 of the fire fighting water 41 changes, the pressure P2 of the foam concentrate 42 in the secondary side foam concentrate pipe 49 changes following the change of the pressure P3, the differential pressure ΔP becomes constant, and the fire fighting water A foam aqueous solution in which 41 and foam stock solution 42 are always mixed at a predetermined mixing ratio is obtained.

  Here, in the equal differential pressure control pilot valve 101, the spring 27 is contracted between the diaphragm retainer 4 in the first operation chamber 6A and the spring receiver 26A. That is, the equal differential pressure control pilot valve 101 is different from the equal differential pressure control pilot valve 100 in that the first shaft 30 is omitted.

  Therefore, in the equal differential pressure control pilot valve 100, as shown in FIG. 8A, the pressure of the reference fluid that is introduced into the first operation chamber 6 and presses the diaphragm 5 downward is the pressure of the first shaft 30. Seeing the diaphragm retainer 4 and the diaphragm 5 from above in the axial direction, it acts on the area excluding the first shaft 30 (S1 = P3a + P3b + P3c). The pressure of the pressure regulating fluid introduced into the second operation chamber 7 and pressing the diaphragm 5 upward is the total area (S2 = P2a + P2b + P2c) when the diaphragm retainer 4 and the diaphragm 5 are viewed from below in the axial direction of the first shaft 30. Act on. As described above, in the equal differential pressure control pilot valve 100, the area S1 where the pressure of the reference fluid acts and the area S2 where the pressure of the pressure regulating fluid act are different from each other in the cross-sectional integral of the first shaft 30. An error occurs in the pressure balance between the reference pressure (reference fluid pressure) P3 and the pressure regulation pressure (pressure fluid pressure) P2 acting on the diaphragm 4 and the diaphragm 5 from above and below.

  On the other hand, in the equal differential pressure control pilot valve 101, as shown in FIG. 8B, the pressure of the reference fluid that is introduced into the first operation chamber 6A and presses the diaphragm 5 downward is applied to the second shaft 31A. Seeing the diaphragm presser 4 and the diaphragm 5 from above in the axial direction, it acts on the entire area (S3 = P3A + P3B + P3C). Further, the pressure of the pressure regulating fluid introduced into the second operation chamber 7 and pressing the diaphragm 5 upward is the entire area (S4 = P2A + P2B + P2C) when the diaphragm retainer 4 and the diaphragm 5 are viewed from below in the axial direction of the second shaft 31A. Act on. As described above, in the equal differential pressure control pilot valve 101, the area S3 on which the reference fluid acts and the area S4 on which the pressure regulating fluid acts are substantially equal. Therefore, the occurrence of an error in the pressure balance between the reference pressure P3 and the regulated pressure P2 acting on the diaphragm retainer 4 and the diaphragm 5 from above and below is suppressed, so that the differential pressure between the regulated pressure P2 and the reference pressure P3 becomes constant. Therefore, the pressure can be adjusted with high accuracy.

  In the equal differential pressure control pilot valve 101, the first through hole 34 is formed on one end side of the second shaft 31A with the hole direction orthogonal to the axial direction of the second shaft 31A. Is formed so that the second through hole 35 communicates with the outer side of the back surface of the valve body 22A at the axial center position of the second shaft 31A with the hole direction aligned with the axial direction of the second shaft 31A. That is, the equal differential pressure control pilot valve 101 is different from the equal differential pressure control pilot valve 100 in that the first through hole 34 and the second through hole 35 are formed in the second shaft 31A.

  Since the equal differential pressure control pilot valve 101 is configured in this way, in the state where the valve body 22A is in contact with the valve seat 21, the primary side fluid introduced into the valve chamber 17 is on the through hole 19 side. Inflow is blocked. Further, the pressure adjusting fluid introduced into the second operation chamber 7 gradually flows into the through hole 19 from a minute gap in the insertion portion of the second shaft 31A with the second divided body 3, and further into the first through hole. 34 and the second through hole 35 and flows into the back surface side of the valve body 22A. The inflow of the pressure adjusting fluid that has flowed into the through hole 19 into the valve chamber 17 is prevented by the contact between the valve body 22 </ b> A and the valve seat 21.

  Therefore, the pressure of the fluid that presses the valve body 22A and the second shaft 31A downward is applied to the valve body 22A and the second shaft 31A from above in the axial direction of the second shaft 31A, as shown in FIG. It acts on the total area (S7 = P1A + P2A). Further, the pressure of the fluid that presses the valve body 22A and the second shaft 31A upward acts on the entire area (S8 = P1B + P2B) when viewing the valve body 22A and the second shaft 31A from below in the axial direction of the second shaft 31A. . Here, P1A is an area in which the pressure of the primary fluid in the valve chamber 17 presses the valve body 22A and the second shaft 31A downward, and P1B is the pressure of the primary fluid in the valve chamber 17 and the valve body 22A and the second shaft. The area where the shaft 31A is pressed upward, P2A is the area where the pressure of the pressure adjusting fluid in the second operation chamber 7 and the through hole 19 presses the valve body 22A and the second shaft 31A downward, and P2B is the back surface of the valve body 22A. The pressure of the pressure regulating fluid on the side is an area for pressing the valve body 22A and the second shaft 31A upward.

  The area P1A where the primary fluid presses the valve body 22A and the second shaft 31A downward is substantially equal to the area P1B where the primary fluid presses the valve body 22A and the second shaft 31A upward. . Further, the area P2A where the pressure regulating fluid presses the valve body 22A and the second shaft 31A downward is equal to the area P2B where the pressure regulating fluid presses the valve body 22A and the second shaft 31A upward. Therefore, the pressure that presses the valve body 22A and the second shaft 31A downward and the pressure that presses the valve body 22A and the second shaft 31A upward cancel each other. Thereby, the valve body 22 </ b> A moves up and down by the urging force of the spring 20. Therefore, even if the pressure fluctuation of the primary side fluid or the pressure regulating fluid occurs, the vertical movement operation of the valve body 22A is not affected and becomes stable.

  On the other hand, in the equal differential pressure control pilot valve 100, when the valve element 22 is in contact with the valve seat 21, the primary fluid introduced into the valve chamber 17 is prevented from flowing into the through hole 19 side. . The primary fluid inserted into the valve chamber 17 also flows into the back surface side of the valve body 22. Further, the pressure adjusting fluid introduced into the second operation chamber 7 gradually flows into the through hole 19 from a minute gap in the insertion portion of the second shaft 31 with the second divided body 3. The inflow of the pressure regulating fluid that has flowed into the through hole 19 into the valve chamber 17 is prevented by the contact between the valve body 22 and the valve seat 21.

  Therefore, the pressure of the fluid that presses the valve body 22 and the second shaft 31 downward is applied to the valve body 22 and the second shaft 31 from above in the axial direction of the second shaft 31 as shown in FIG. It acts on the total area (S9 = P1a ′ + P2a). The pressure of the fluid that presses the valve body 22 and the second shaft 31 upward is the entire area (S10 = P1b ′ + P1b) when the valve body 22 and the second shaft 31 are viewed from below in the axial direction of the second shaft 31. Works. Here, P1a ′ is an area where the pressure of the primary fluid in the valve chamber 17 presses the valve body 22 and the second shaft 31 downward, and P1b ′ and P1b are pressures of the primary fluid in the valve chamber 17 22 is an area where the second shaft 31 and the second shaft 31 are pressed upward, and P2a is an area where the pressure of the pressure adjusting fluid in the second operation chamber 7 and the through hole 19 presses the valve body 22 and the second shaft 31 downward.

The area P1a ′ where the primary fluid presses the valve body 22 and the second shaft 31 downward is substantially equal to the area P1b ′ where the primary fluid presses the valve body 22 and the second shaft 31 upward. ing. Therefore, since the fluids acting on the area P1a ′ and the area P1b ′ are the same, the pressure of the primary side fluid that presses the valve body 22 and the second shaft 31 downward and the valve body 22 and the second shaft 31 upward. The pressure of the primary fluid to be pressed cancels out.
Further, the area P2a where the pressure regulating fluid presses the valve body 22 and the second shaft 31 downward is equal to the area P2b where the primary fluid presses the valve body 22 and the second shaft 31 upward. However, since the fluid acting on the area P2a is the pressure regulating fluid and the fluid acting on the area P1b is the primary fluid, the pressure P1 of the pressure regulating fluid and the pressure P2 of the primary fluid are different. 22 moves without being balanced.

  In each of the above embodiments, the equal differential pressure control pilot valves 100 and 101 detect the pressure P3 of the fire-extinguishing water 41 in the water supply pipe 45, and the secondary pressure P2 of the control valve 200 is set to a spring pressure from the pressure P3. Although the pressure is adjusted to be higher by α, the secondary pressure P2 of the control valve 200 may be adjusted to be lower than the pressure P3 by the spring pressure α. In this case, for example, the fire extinguishing water 41 is introduced into the second operation chamber 7 from the secondary side connection port 11, and the secondary foam stock solution 42 is introduced into the first operation chambers 6 and 6A from the reference fluid connection port 8. This can be achieved. Alternatively, the urging force of the spring 27 can be realized by urging the diaphragm 5 in the direction in which the valve bodies 22 and 22A are seated on the valve seat 21. For example, the axial movement of the spring receivers 26, 26 </ b> A with respect to the adjustment screw 28 may be restricted, and the spring 27 may be extended between the spring receiver 26 and the piston 24. At this time, in Embodiment 1, it is necessary to regulate the axial movement of the piston 24 relative to the first shaft 30.

Further, in each of the above embodiments, the valve device is configured such that the valve bodies 22 and 22A are seated on the valve seat 21 when P3 + α ≦ P2, but the valve device is configured such that the valve device operates when P3 + α ≦ P2. The bodies 22 and 22 </ b> A may be configured to be separated from the valve seat 21.
Moreover, in each said embodiment, although the diaphragm 5 is used as a partition member, a partition member is not limited to the diaphragm 5, The pressure difference in the 1st and 2nd operation chambers 6, 6A, 7 For example, a piston disposed so as to slide on the inner wall surfaces of the first and second operation chambers 6, 6A, 7 may be used.

It is sectional drawing which shows the valve opening state of the equal differential pressure control pilot valve which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the valve closing state of the equal differential pressure control pilot valve which concerns on Embodiment 1 of this invention. It is a block diagram which shows typically the whole structure of the foam mixing apparatus to which the equal differential pressure control pilot valve which concerns on Embodiment 1 of this invention is applied. It is sectional drawing which shows the valve closing state of the control valve in the foam mixing apparatus shown by FIG. It is sectional drawing which shows the valve opening state of the control valve in the foam mixing apparatus shown by FIG. It is sectional drawing which shows the valve opening state of the equal differential pressure control pilot valve which concerns on Embodiment 2 of this invention. It is sectional drawing which shows the valve closing state of the equal differential pressure control pilot valve which concerns on Embodiment 2 of this invention. It is a figure explaining the effect of the equal differential pressure control pilot valve concerning Embodiment 2 of this invention. It is a figure explaining the effect of the equal differential pressure control pilot valve concerning Embodiment 2 of this invention.

Explanation of symbols

  1, 1A Main body, 5 Diaphragm (partition member), 6, 6A First operation chamber, 7 Second operation chamber, 10 Primary side connection port (inlet, valve device), 12 Cylinder connection port (outlet, valve device) 16, 18, 19 Through-hole (valve device), 17 Valve chamber (valve device), 21 Valve seat (valve device), 22, 22A Valve body (main valve, valve device), 24 Piston (biasing means), 26, 26A Spring receiver (biasing means), 27 Spring (biasing means), 28 Adjustment screw (biasing means), 30 First shaft (biasing means), 31, 31A Second shaft (power transmission member), 100, 101 An equal differential pressure control pilot valve.

Claims (3)

A valve device having a main valve disposed so as to be able to come into contact with and separate from a valve seat separating the inlet and the outlet;
An operation chamber having an axial direction of the main valve contacting and separating from the valve seat;
The operation chamber is disposed so as to be displaceable in the axial direction, and the operation chamber is divided into a first operation chamber into which a reference pressure is introduced in the axial direction and a second operation chamber into which a pressure regulation pressure is introduced. A partition member formed;
Biasing means for biasing the partition member in the axial direction;
A power transmission member that transmits the axial displacement of the partition member to the main valve to bring the main valve into and out of contact with the valve seat;
An equal differential pressure control pilot valve characterized by comprising:   2. The equal differential pressure control pilot valve according to claim 1, wherein the partition member is a diaphragm.   3. The equal differential pressure control pilot valve according to claim 1, wherein the biasing means is configured to be capable of adjusting the pressure for biasing the partition member.

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