JPWO2018073945A1 - Gas mixer - Google Patents

Abstract

  The gas mixer (1) includes a pilot pressure reducing valve (2) and an equal pressure valve (3). The pilot pressure reducing valve (2) includes a pilot housing (21), a pilot valve shaft (22), a second pilot housing (23), a pilot seal member (24), and a pilot valve body (26). . When the pilot valve shaft (22) reciprocates in the axial direction, a state in which the pilot valve body (26) and the second pilot housing (23) are in contact with each other is realized. In a state where the pilot valve body (26) and the second pilot housing (23) are in contact, the pilot housing (21) has a first pressure space (21A), a second pressure space (21B), and a third A pressure space (21C) is formed. The third pressure space (21C) and the second pressure space (21B) are in communication. The pilot seal member (24) is fixed to the pilot housing (21).

Description

  The present invention relates to a gas mixer.

  A gas mixer may be used to mix and supply two different types of gases. The gas mixer has a structure in which, for example, a gas having a primary pressure is reduced to a predetermined secondary pressure at an equal pressure by a pressure reducing valve and mixed (see, for example, Patent Document 1).

JP 2006-349030 A

  In a gas mixer, it is preferable that responsiveness is high. The objective of this invention is providing the gas mixer excellent in the responsiveness.

  The gas mixer according to the present invention includes a pilot pressure reducing valve, an isobaric valve, and a mixing unit. The pilot pressure reducing valve discharges the pressure of the inflowing pilot gas by reducing the pressure to the pilot pressure. The isobaric valve is connected to the pilot pressure reducing valve, and discharges the introduced first gas and the second gas at a reduced pressure based on the pilot pressure of the pilot gas discharged from the pilot pressure reducing valve. The mixing unit flows in the first gas and the second gas discharged from the isobaric valve, and mixes and discharges the first gas and the second gas. The pilot pressure reducing valve includes a pilot housing, a pilot valve shaft, a second pilot housing, a pilot seal member, a pilot pressing member, and a pilot valve body. The pilot valve shaft is disposed in the pilot housing and can reciprocate in the axial direction. The second pilot housing is fixedly disposed with respect to the pilot housing in the pilot housing. The pilot seal member is disposed in contact with the outer surface of the pilot valve shaft and the inner surface of the pilot housing, and maintains airtightness between the pilot valve shaft and the pilot housing. The pilot pressing member is disposed in contact with the pilot valve shaft and presses the pilot valve shaft in the axial direction. The pilot valve body is installed on the pilot valve shaft. When the pilot valve shaft reciprocates in the axial direction, a state where the pilot valve body and the second pilot housing are in contact with each other and a state where they are separated are realized. A pilot inflow passage through which pilot gas flows in and a pilot outflow passage through which pilot gas reduced to the pilot pressure flows are formed in the pilot housing. In a state where the pilot valve body and the second pilot housing are in contact with each other, a first pressure space, a second pressure space, and a third pressure space are formed in the pilot housing. The first pressure space is surrounded by the pilot valve shaft, the pilot housing, and the second pilot housing, and is connected to the pilot inflow passage. The second pressure space is disposed on the side opposite to the first pressure space when viewed from the pilot valve body, and is connected to the pilot outflow passage. The third pressure space is disposed on the side opposite to the first pressure space when viewed from the pilot seal member and in contact with the end of the pilot valve shaft. The third pressure space and the second pressure space communicate with each other. The pilot seal member is fixed with respect to the pilot housing.

  In the gas mixer of the present invention, the pressure of the introduced first gas and the second gas is reduced to an equal pressure based on the pilot pressure of the pilot gas discharged from the pilot pressure reducing valve connected to the pilot pressure reducing valve. Including an isobaric valve. Thereby, the pressures of the first gas and the second gas can be adjusted by adjusting the pilot pressure of the pilot gas discharged from the pilot pressure reducing valve.

  In the gas mixer of the present invention, the third pressure space and the second pressure space of the pilot pressure reducing valve communicate with each other, so that the differential pressure between the third pressure space and the second pressure space applied to the pilot valve shaft is increased. The corresponding force is reduced. However, an axial force corresponding to the differential pressure between the third pressure space and the first pressure space is applied to the pilot seal member. Here, in order to maintain the state in which the pilot valve body and the second pilot housing are in contact with each other, an axial force (pressing load) is applied to the pilot valve shaft so as to press the pilot valve body against the second pilot housing. .

  When the pilot seal member is fixed to the pilot valve shaft, a force corresponding to the differential pressure between the third pressure space and the first pressure space is applied to the pilot valve shaft. As a result, in order to maintain the contact state between the pilot valve body and the second pilot housing, the pilot valve shaft supports the differential pressure between the third pressure space and the first pressure space in addition to the above pressing load. It is necessary to give the power to do.

Specifically, for example, the maximum differential pressure between the third pressure space and the first pressure space is 0.45 MPa, the minimum differential pressure between the third pressure space and the first pressure space is 0.15 MPa, and the axial direction of the pilot seal member Is applied to the pilot valve shaft in order to maintain the state in which the pilot valve body and the second pilot housing are in contact with each other when the cross-sectional area in the plane perpendicular to the axis is 18.8 mm ² and the pressing load is 5.89 N The force is set as follows.

  The force applied to the pilot seal member is obtained by multiplying the differential pressure between the third pressure space and the first pressure space by the cross-sectional area in a plane perpendicular to the axial direction of the pilot seal member. When the differential pressure between the third pressure space and the first pressure space and the cross-sectional area of the pilot seal member are as described above, the pilot when the differential pressure between the third pressure space and the first pressure space becomes the maximum differential pressure. The force applied to the seal member is 8.46N. On the other hand, when it becomes the minimum differential pressure, the force applied to the pilot seal member is 2.82N. Thus, the force applied to the pilot seal member changes with the change in the differential pressure between the third pressure space and the first pressure space.

  In order to maintain the state in which the pilot valve body and the second pilot housing are in contact with each other, the pilot valve shaft has a force corresponding to the maximum differential pressure between the third pressure space and the first pressure space, That is, it is necessary to apply a force of 14.35 N obtained by adding 8.46 N to the pressing load 5.89 N. However, when the differential pressure between the third pressure space and the first pressure space becomes low, an excessive force is applied to the pilot valve shaft. The force necessary to maintain the state in which the pilot valve body and the second pilot housing are in contact with each other with a minimum differential pressure between the third pressure space and the first pressure space is 2 against the pressing load 5.89N. It becomes 8.71N which added .82N. That is, when the differential pressure between the third pressure space and the first pressure space becomes the minimum differential pressure, an excessive force of 5.64 N is applied to the pilot valve shaft.

  That is, the pilot valve shaft becomes unresponsive in the above excessive force range when the differential pressure between the third pressure space and the first pressure space becomes low. As a result, when the pilot seal member is fixed to the pilot valve shaft, the response of the pilot pressure reducing valve is lowered.

  On the other hand, in the gas mixer of the present invention, the pilot seal member is fixed to the pilot housing. By doing in this way, the force corresponding to the pressure difference between the third pressure space and the first pressure space applied to the pilot seal member can be handled by the pilot housing. Therefore, it is not necessary to apply a force corresponding to the differential pressure between the third pressure space and the first pressure space to the pilot valve shaft. As a result, the range in which the pilot valve shaft does not react to the change in pressure in the second pressure space is reduced, and the responsiveness of the pilot pressure reducing valve can be improved.

  Thus, according to the gas mixer of this invention, the gas mixer which is excellent in responsiveness can be provided.

  In the gas mixer, the isobaric valve includes an isobaric housing, a first isobaric valve shaft, a second isobaric valve shaft, a first isobaric pressure member, a second isobaric pressure member, and a first soft valve. The valve body, the second soft valve body, the first hard valve body, and the second hard valve body may be included. The first isobaric valve shaft and the second isobaric valve shaft are disposed in the isobaric housing and can reciprocate in the axial direction. The first isobaric pressing member is disposed in the isobaric housing, constitutes a part of the wall surface of the pilot gas chamber, which is a space connected to the pilot pressure reducing valve, and contacts the first isobaric valve shaft to form the first The isobaric valve shaft is pressed in the axial direction. The second isobaric pressing member is disposed in the isobaric housing, constitutes another part of the wall surface of the pilot gas chamber, contacts the second isobaric valve shaft, and causes the second isobaric valve shaft to move in the axial direction. Press. The first soft valve body is installed on the first isobaric valve shaft. The second soft valve body is installed on the second isobaric valve shaft. The first hard valve body is installed so as to be capable of reciprocating in the axial direction with respect to the first isobaric valve shaft. The second hard valve body is installed so as to be capable of reciprocating in the axial direction with respect to the second isobaric valve shaft. In the isobaric housing, there are a first gas inflow passage, a first gas discharge passage, a first gas intermediate passage, a second gas inflow passage, a second gas discharge passage, and a second gas intermediate passage. It is formed. The first gas flows into the first gas inflow path. The first gas is discharged from the first gas discharge path. The first gas intermediate path connects the first gas inflow path and the first gas discharge path. The second gas flows into the second gas inflow path. The second gas is discharged from the second gas discharge path. The second gas intermediate path connects the second gas inflow path and the second gas discharge path. The first soft valve body is disposed at a connection portion between the first gas inflow passage and the first gas intermediate passage. The first hard valve body is disposed at a connection portion between the first gas intermediate path and the first gas discharge path. A 2nd soft valve body is arrange | positioned at the connection part of a 2nd gas inflow path and a 2nd gas intermediate path. The second hard valve body is disposed at a connection portion between the second gas intermediate path and the second gas discharge path.

  By doing in this way, the rigid valve body installed in the isobaric valve shaft is reciprocated in the axial direction, and the connection part between the gas intermediate path and the gas discharge path is opened and closed, so that the gas inflow path to the gas discharge path The minute flow rate of the flowing gas can be controlled stably. Further, when the space between the gas intermediate path and the gas inflow path is closed by the soft valve body fixed to the isobaric valve shaft, the gas inflow path is sealed with the soft valve body. And the gas discharge path can be stably maintained in a sealed state. As a result, it is possible to achieve both control of a minute gas flow rate and a reliable sealed state. By adopting the above-mentioned isobaric valve, a high-performance gas can be obtained by combining a pilot pressure reducing valve with excellent responsiveness and an isobaric valve that can achieve both fine gas flow control and reliable sealing. A mixer can be provided. The hard valve body is made of a material that does not substantially deform when closed, for example, a metal. The soft valve body is made of a material that can be deformed when closed, such as resin or rubber.

  In the gas mixer, the first isobaric pressing member and the second isobaric pressing member may include an elastic member and a support member. The support member is made of a material having higher rigidity than the elastic member, and supports the elastic member. The elastic member includes a base portion and a protruding portion. The base portion has a disk shape. The protruding portion is disposed so as to surround the outer periphery of the base portion, and protrudes in the direction in which the pilot gas chamber expands. The base portion is supported by the support member over the entire area. By doing in this way, pilot pressure can be transmitted to an isobaric valve axis | shaft, suppressing the loss in an elastic member.

  In the gas mixer, the mixing unit may include a mixing ratio adjuster and a merger. The mixing ratio adjuster adjusts the mixing ratio of the first gas and the second gas discharged from the isobaric valve, and discharges the first gas and the second gas from the first gas channel and the second gas channel, respectively. To do. The merger is connected to the first gas channel and the second gas channel, and has a cross-sectional area perpendicular to the direction in which the first gas and the second gas flow is larger than that of the first gas channel and the second gas channel. Has a chamber. By doing in this way, 1st gas and 2nd gas can be mixed with uniform and high mixing accuracy.

  In the gas mixer, the discharge direction of the first gas from the first gas flow path to the merger may be along the discharge direction of the second gas from the second gas flow path to the merger. . By doing in this way, it can prevent that the 1st gas and 2nd gas which were discharged from the isobaric valve collide and mixing accuracy falls.

  As is clear from the above description, according to the gas mixer of the present invention, a gas mixer having excellent responsiveness can be provided.

It is the schematic which shows the structure of a gas mixer. It is a schematic sectional drawing which shows the structure of a pilot pressure reducing valve. It is a schematic sectional drawing which shows the structure of an equal pressure valve. It is a schematic sectional drawing which expands and shows the principal part of an equal pressure valve. It is a schematic sectional drawing for demonstrating operation | movement of a pilot pressure-reduction valve. It is a schematic sectional drawing for demonstrating operation | movement of a pilot pressure-reduction valve. It is a schematic sectional drawing for demonstrating operation | movement of an equal pressure valve. It is a schematic sectional drawing for demonstrating operation | movement of an equal pressure valve. It is a schematic sectional drawing for demonstrating operation | movement of an equal pressure valve.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

  Referring to FIG. 1, the gas mixer 1 in the first embodiment includes a pilot pressure reducing valve 2, an equal pressure valve 3, a mixing unit 5, and a flow rate adjusting valve 6.

  A first pipe 91, a second pipe 92, a third pipe 93, and a fourth pipe 94 are connected to the equal pressure valve 3. The first pipe 91 is connected to the first gas inflow path 31A. The second pipe 92 is connected to the second gas inflow path 31D. The third pipe 93 is connected to the first gas discharge path 31B. The fourth pipe 94 is connected to the second gas discharge path 31E.

  A fifth pipe 95 and a sixth pipe 96 are connected to the pilot pressure reducing valve 2. One end of the fifth pipe 95 is connected to the pilot inflow passage 27 of the pilot pressure reducing valve 2. The other end of the fifth pipe 95 is connected to the second pipe 92. One end of the sixth pipe 96 is connected to the pilot outflow passage 28. The other end of the sixth pipe 96 is connected to the pilot gas chamber 34 in the isobaric housing 31 of the isobaric valve 3.

  The mixing unit 5 includes a merger 51 and a mixing ratio adjuster 53. A third pipe 93 and a fourth pipe 94 are connected to the mixing ratio adjuster 53. The merger 51 and the mixing ratio adjuster 53 are connected by a seventh pipe 97 and an eighth pipe 98. The seventh pipe 97 is connected to the first gas flow path 51A. The eighth pipe 98 is connected to the second gas flow path 51B. A ninth pipe 99 is disposed between the mixing unit 5 and the flow rate adjustment valve 6.

  Referring to FIG. 2, pilot pressure reducing valve 2 includes pilot housing 21, pilot valve shaft 22, second pilot housing 23, pilot seal member 24, pilot pressing member 25, and pilot valve body 26. Prepare.

  The pilot housing 21 includes a first outer frame portion 211 and a second outer frame portion 212. The second outer frame portion 212 has a bottom 212B at one end and a multistage cylindrical internal space having an opening at the other end. The inner space of the second outer frame portion 212 becomes smaller in diameter as it approaches the one end portion. The first outer frame portion 211 has a multistage cylindrical pilot internal space 21D having openings at both ends. The pilot inner space 21D of the first outer frame portion 211 has a diameter that decreases as it approaches one end. The first outer frame portion 211 and the second outer frame portion 211 are fitted together so that the outer peripheral surface of the other end portion of the first outer frame portion 211 and the inner peripheral surface of the other end portion of the second outer frame portion 212 are in contact with each other. The outer frame portion 212 is connected.

  The adjustment shaft 211 </ b> C is disposed so as to penetrate one end of the first outer frame portion 211. The adjustment unit 211B is connected to one end of the adjustment shaft 211C. The other end of the adjustment shaft 211C is located in the pilot internal space 21D.

  The pilot pressure reducing valve 2 includes a pilot spring 251 in the pilot internal space 21D. One end portion of the pilot spring 251 is in contact with the first support portion 211D. The other end of the adjustment shaft 211C is in contact with the opposite side of the first support portion 211D that is in contact with the pilot spring 251.

  The pilot pressing member 25 includes a diaphragm 252, a support portion 253, and a pressing portion 254. A diaphragm 252 having a through hole at the center is supported so as to be sandwiched between the first outer frame portion 211 and the second outer frame portion 212. The diaphragm 252 includes a protrusion 252A that protrudes toward the pilot internal space 21D on the outer periphery. The pressing part 254 has a shape including a disk-shaped main body part and a protruding part protruding in the axial direction from the main body part. The main body portion of the pressing portion 254 is positioned on the second outer frame portion 212 side when viewed from the diaphragm 252, and the protruding portion enters the first outer frame portion 211 side by passing through the through hole of the diaphragm 252. The support part 253 has a disk shape having a through hole in the center. The support portion 253 is disposed on the first outer frame portion 211 side when viewed from the diaphragm 252. The diaphragm 252 is sandwiched between the pressing portion 254 and the support portion 253 in a state where the protruding portion of the pressing portion 254 is inserted into the through hole of the support portion 253. The support portion 253 is disposed in contact with the other end portion of the pilot spring 251.

  The pilot valve shaft 22 is disposed in the second outer frame portion 212. The pilot valve shaft 22 is formed with a through hole 22 </ b> A that opens at one end, extends in the axial direction, and penetrates in the radial direction at a position closer to the other end than the pilot valve body 26. . The pilot valve shaft 22 contacts the pressing portion 254 at the other end. The pilot valve shaft 22 is installed so as to be movable in the axial direction.

  The second pilot housing 23 is installed so as to surround a part of the outer periphery of the pilot valve shaft 22. A bearing portion 232 is disposed between the second pilot housing 23 and the pilot valve shaft 22. The second pilot housing 23 is fixed in an airtight manner with an O-ring 231 sandwiched between the inner peripheral surface of the center portion of the second outer frame portion 212. The second pilot housing 23 is formed with a housing flow path 23A that connects the second pressure space 21B and the first pressure space 21A. The through hole 22A of the pilot valve shaft 22 communicates with the housing flow path 23A. As a result, the third pressure space 21C and the second pressure space 21B communicate with each other.

  The pilot valve body 26 has an annular shape. By inserting the pilot valve shaft 22 into the pilot valve body 26, the pilot valve body 26 is fixed to the pilot valve shaft 22. When the pilot valve shaft 22 reciprocates in the axial direction, a state where the pilot valve body 26 and the second pilot housing 23 are in contact with each other and a state where they are separated are realized. A valve body fixing portion 261 having a cylindrical shape is arranged so as to cover the outer peripheral portion of the pilot valve body 26.

  The pilot seal member 24 includes a first seal fixing part 241, an O-ring 242, and a second seal fixing part 243. The pilot seal member 24 is fixed to the inner peripheral surface of the second outer frame portion 212 on the side opposite to the second pilot housing 23 when viewed from the pilot valve body 26. A coil spring 262 is disposed between the second seal fixing portion 243 and the valve body fixing portion 261. One end of the coil spring 262 contacts the second seal fixing portion 243. The other end of the coil spring 262 contacts the valve body fixing part 261. The O-ring 242 is disposed so as to be sandwiched between the first seal fixing portion 241 and the second seal fixing portion 243. The O-ring 242 is disposed so as to contact the outer peripheral surface of the pilot valve shaft 22 and the inner peripheral surface of the second outer frame portion 212. The pilot valve shaft 22 and the second outer frame portion 212 are sealed by an O-ring 242.

  A first pressure space 21 </ b> A surrounded by the pilot valve shaft 22, the pilot housing 21 and the second pilot housing 23 is formed in the pilot housing 21. The first pressure space 21 </ b> A is connected to the pilot inflow passage 27. The second pressure space 21 </ b> B is disposed on the side opposite to the first pressure space 21 </ b> A when viewed from the pilot valve body 26, and is connected to the pilot outflow passage 28. A third pressure space 21 </ b> C is formed on the side opposite to the first pressure space 21 </ b> A when viewed from the pilot seal member 24, and arranged to contact the end of the pilot valve shaft 22. The third pressure space 21C communicates with the second pressure space 21B.

  Referring to FIGS. 3 and 4, the equal pressure valve 3 includes an equal pressure housing 31, a first equal pressure valve shaft 32, a first equal pressure pressing member 35, a first soft valve body 371, and a first hard valve. A second pressure reduction valve 301 including a valve body 372, a second pressure equalizing valve shaft 33, a second pressure equalizing pressing member 36, a second soft valve body 381, and a second hard valve body 382. And a pressure reducing valve 302. The first pressure reducing valve 301 and the second pressure reducing valve 302 are arranged in pairs so as to face each other in the axial direction. The first isobaric pressing member 35 is disposed in the isobaric housing 31 and constitutes a part of the wall surface of the pilot gas chamber 34 that is a space connected to the pilot pressure reducing valve 2. The second isobaric pressing member 36 constitutes another part of the wall surface of the pilot gas chamber 34.

  Between the first pressure reducing valve 301 and the second pressure reducing valve 302, a pilot gas chamber 34 surrounded by the first equal pressure pressing member 35, the second equal pressure pressing member 36, and the equal pressure housing 31 is formed. The The pilot gas chamber 34 is connected to the pilot outflow passage 28.

  Since the first pressure reducing valve 301 and the second pressure reducing valve 302 have the same structure, the second pressure reducing valve 302 will be mainly described below. Referring to FIG. 4, the second pressure reducing valve 302 includes a first valve housing 311 and a second valve housing 312. The first valve housing 311 has a multistage cylindrical internal space having openings at both ends. The second valve housing 312 has a multistage cylindrical internal space having a bottom at one end and an opening at the other end.

  The second isobaric pressing member 36 includes an elastic member 351 that is a diaphragm, a support member 352, a fixing portion 353, and a pressing portion 354. The elastic member 351 has a disk shape having a through hole in the center. The outer peripheral portion of the elastic member 351 is connected to the isobaric housing 31. The elastic member 351 includes a base portion 351A having a disk shape and a protruding portion 351B. The protruding portion 351B is disposed so as to surround the outer periphery of the base portion 351A, and protrudes in the direction in which the pilot gas chamber 34 expands. The base portion 351A is sandwiched and supported by a pair of support members 352 over the entire area.

  The second isobaric valve shaft 33 is disposed in the first valve housing 311. The second isobaric valve shaft 33 is formed with a through-hole 33A that opens at one end, extends toward the other end, and penetrates in the radial direction near the other end. One end of the second isobaric valve shaft 33 is in contact with the pressing portion 354. The outer peripheral surface of one end of the second isobaric valve shaft 33 is supported in the radial direction by the bearing portion 322 with respect to the one end of the first valve housing 311. An engaging portion 321 protruding in the radial direction is fixed to the outer peripheral surface of the second isobaric valve shaft 33. The second isobaric valve shaft 33 is installed so as to be movable in the axial direction.

  The second hard valve body 382 has a hollow cylindrical shape. A predetermined gap T is formed in the axial direction between the second hard valve body 382 and the engaging portion 321. The second isobaric valve shaft 33 is inserted into the second hard valve body 382. The second hard valve body 382 includes a tapered surface 382A whose outer diameter decreases toward one end. A space between the second hard valve body 382 and the second isobaric valve shaft 33 is sealed by an O-ring 42. The second hard valve body 382 is installed to be movable in the axial direction relative to the second isobaric valve shaft 33. The second hard valve body 382 is installed so that the taper surface 382A of the second hard valve body 382 and the first valve housing 311 are in contact with each other and the taper surface 382A and the first valve housing 311 are not in contact with each other. The

  A valve seat 43 is disposed at the other end of the first valve housing 311. The valve seat 43 has an annular shape. The valve seat 43 is disposed in a state sandwiched between the first valve housing 311 and the second valve housing 312. The valve seat 43 contacts one end of the coil spring 41. The other end of the coil spring 41 is in contact with the second hard valve body 382.

  The second soft valve body 381 has an annular shape. The second isobaric valve shaft 33 is inserted into the second soft valve body 381. The second soft valve body 381 can come into contact with the surface of the valve seat 43 opposite to the side with which the coil spring 41 contacts. The valve body fixing | fixed part 44 which has a cylindrical shape is arrange | positioned so that the outer peripheral surface of the 2nd soft valve body 381 may be covered. The second soft valve body 381 is movable in the axial direction integrally with the second isobaric valve shaft 33.

  An O-ring 47 is disposed between the outer peripheral surface of the other end of the second isobaric valve shaft 33 and the second valve housing 312. A first fixing portion 46 and a second fixing portion 48 having an annular shape are arranged so as to sandwich the O-ring 47 in the axial direction. The first fixing portion 46 is in contact with one end portion of the coil spring 45. The other end of the coil spring 45 is in contact with the valve body fixing portion 44.

  Further, referring to FIG. 3, in the isobaric housing 31, a first gas inflow passage 31 </ b> A into which the first gas A flows, a first gas discharge passage 31 </ b> B through which the first gas A is discharged, and a first gas A first gas intermediate path 31C connecting the inflow path 31A and the first gas discharge path 31B, a second gas inflow path 31D into which the second gas B flows, and a second gas discharge path through which the second gas B is discharged. 31E and a second gas intermediate path 31F that connects the second gas inflow path D and the second gas discharge path E are formed. A first soft valve element 371 is disposed at a connection portion between the first gas inflow passage 31A and the first gas intermediate passage 31C. A first hard valve body 372 is disposed at a connection portion between the first gas intermediate passage 31C and the first gas discharge passage 31B. The 2nd soft valve body 381 is arrange | positioned at the connection part of 2nd gas inflow path 31D and 2nd gas intermediate path 31F. A second hard valve body 382 is disposed at a connection portion between the second gas intermediate path 31F and the second gas discharge path 31E.

  Referring to FIG. 1, mixing unit 5 includes a mixing ratio adjuster 53 and a merger 51. The merger 51 is connected to the first gas channel 51A and the second gas channel 51B, and the cross-sectional area perpendicular to the direction in which the first gas A and the second gas B flows is the first gas channel 51A and the second gas. The merge chamber 52 is larger than the flow path 51B. The discharge direction of the first gas A from the first gas flow path 51A to the merger 51 is in line with the discharge direction of the second gas B from the second gas flow path 51B to the merger 51 (more specifically, coincidence). To be).

  Next, the operation of the gas mixer 1 will be described. First, the pilot pressure reducing valve 2 is activated. Referring to FIG. 2, the pilot pressure is set by rotating adjustment portion 211B to move adjustment shaft 211C in the axial direction and compressing pilot spring 251 in the axial direction.

  Referring to FIGS. 2 and 5, second gas B (for example, carbon dioxide) is supplied to pilot inflow passage 27 through second pipe 92 and fifth pipe 95. When the pressure in the second pressure space 21B is higher than the set pilot pressure, the pilot valve body 26 is closed. On the other hand, referring to FIG. 2 and FIG. 6, when the pressure in second pressure space 21 </ b> B becomes lower than the set pilot pressure, pilot valve shaft 22 is moved in the axial direction by pilot pressing member 25. It is moved to the pilot seal member 24 side. Thereby, a gap S is formed between the pilot valve body 26 and the second pilot housing 23. From the formed gap S, the gas flows into the second pressure space 21B. As a result, the pressure in the second pressure space 21B is adjusted to the pilot pressure that is the set pressure. Referring to FIG. 1, the pilot gas discharged from pilot pressure reducing valve 2 flows into pilot gas chamber 34 through sixth pipe 96. As a result, the pressure in the pilot gas chamber 34 is adjusted to the pilot pressure.

  With reference to FIGS. 1, 4, and 7, the first gas A (for example, argon) is supplied to the isobaric valve 3 through the first pipe 91. A second gas B (for example, carbon dioxide) is supplied to the equal pressure valve 3 via the second pipe 92. Hereinafter, the pressure adjustment of the second gas B will be described. Since the first gas A is depressurized to the same pressure as the second gas B by the same mechanism as the second gas B, description thereof is omitted. When the pressure of the second gas discharge path 31E is higher than the pilot pressure, the second hard valve body 382 and the second soft valve body 381 are closed. On the other hand, referring to FIGS. 4 and 8, when the pressure of the second gas discharge passage 31E is lower than the pilot pressure, the second isobaric valve shaft 33 is moved by the second isobaric pressure member 36. , Move to the bottom side of the second valve housing 312 in the axial direction. At this time, until the engaging portion 321 of the second isobaric valve shaft 33 contacts the second hard valve body 382, only the second isobaric valve shaft 33 moves in the axial direction. Accordingly, the second soft valve body 381 is moved integrally with the second isobaric valve shaft 33 to the bottom side of the second valve housing 312 in the axial direction. Therefore, a gap U is formed between the second soft valve body 381 and the valve seat 43. The gap U opens the space between the second gas inflow passage 31D and the second gas intermediate passage 31F.

  Referring to FIGS. 4 and 9, thereafter, the engaging portion 321 of the second isobaric valve shaft 33 comes into contact with the second hard valve body, and the second hard valve body 382 is integrally formed with the second isobaric valve shaft 33. Moves to the bottom side of the second valve housing 312. As a result, a gap P is formed between the second hard valve body 382 and the first valve housing 311. The gap P allows communication between the second gas intermediate path 31F and the second gas discharge path 31E. Thereby, the second gas B decompressed to a desired pressure is supplied to the mixing unit 5 via the fourth pipe 94.

  And in the mixing part 5, the 2nd gas B and the 1st gas A pressure-reduced by the same mechanism as the 2nd gas B are mixed. Specifically, the flow rate is adjusted in the mixing ratio adjuster 53 so that the first gas A and the second gas B have a desired mixing ratio, and the combined gas is combined in the combiner 51 to form a mixed gas. Thereafter, the flow rate of the mixed gas is adjusted by the flow rate adjusting valve 6, and the mixed gas is supplied to the supply target.

  Here, in the gas mixer 1 of the present embodiment, the pilot seal member 24 is fixed to the pilot housing 21 in the pilot pressure reducing valve 2. By doing in this way, the force corresponding to the differential pressure between the third pressure space and the first pressure space applied to the pilot seal member 24 can be handled by the pilot housing 21. Therefore, it is not necessary to apply a force corresponding to the differential pressure between the third pressure space and the first pressure space to the pilot valve shaft 22. As a result, the range in which the pilot valve shaft 22 does not react to the change in pressure in the second pressure space is reduced, and the responsiveness of the pilot pressure reducing valve 2 can be improved.

  Further, in the isobaric valve 3, the second hard valve body 382 installed on the second isobaric valve shaft 33 is reciprocated in the axial direction to open and close the connecting portion between the second gas intermediate passage 31F and the second gas discharge passage 31E. By doing so, it is possible to stably control the minute flow rate of the gas flowing from the second gas inflow passage 31D to the second gas discharge passage 31E. Further, when the space between the second gas intermediate passage 31F and the second gas inflow passage 31D is closed by the second soft valve body 381 fixed to the second isobaric valve shaft 33, the second gas discharge passage 31E and Is sealed by the second soft valve body 381, the state where the space between the second gas inflow passage 31 </ b> D and the second gas discharge passage 31 </ b> E is sealed can be stably maintained. As a result, it is possible to achieve both control of a minute gas flow rate and a reliable sealed state.

  Further, the elastic member 351 in the equal pressure valve 3 has a base portion 351A supported by the support member 352 over the entire area. By doing so, the pilot pressure can be transmitted to the second isobaric valve shaft 33 while suppressing the loss in the elastic member 351.

  The merger 51 in the mixing unit 5 has a merge chamber 52 having a cross-sectional area perpendicular to the direction in which the first gas A and the second gas B flow is larger than that of the first gas channel 51A and the second gas channel 51B. . By doing in this way, the 1st gas A and the 2nd gas B can be mixed with uniform and high mixing accuracy.

  The discharge direction of the first gas A from the first gas flow path 51A to the merger 51 is along the discharge direction of the second gas A from the second gas flow path 51B to the merger 51. . By doing in this way, it can prevent that the 1st gas A and the 2nd gas B which were discharged from the equal pressure valve 3 collide, and mixing accuracy falls.

  The gas mixer of the present invention can be particularly advantageously applied to a gas mixer that requires high responsiveness.

  DESCRIPTION OF SYMBOLS 1 Gas mixer, 2 Pilot pressure-reduction valve, 21 Pilot housing, 211 1st outer frame part, 211B adjustment part, 211C Adjustment shaft, 211D 1st support part, 212 2nd outer frame part, 212B Bottom part, 21A 1st pressure space , 21B second pressure space, 21C third pressure space, 21D pilot internal space, 22 pilot valve shaft, 22A through hole, 23 second pilot housing, 231 O-ring, 232 bearing portion, 23A housing flow path, 24 pilot seal member , 241 First seal fixing part, 242 O-ring, 243 Second seal fixing part, 25 Pilot pressing member, 251 Pilot spring, 252 Diaphragm, 252A Protruding part, 253 Supporting part, 254 Pressing part, 26 Pilot valve body, 261 Valve Body fixing part, 262 coil Spring, 27 Pilot inflow path, 28 Pilot outflow path, 3 Isobaric valve, 301 1st pressure reducing valve, 302 2nd pressure reducing valve, 31 Isobaric housing, 311 1st valve housing, 312 2nd valve housing, 31A 1st gas inflow Passage, 31B first gas discharge passage, 31C first gas intermediate passage, 31D second gas inflow passage, 31E second gas discharge passage, 31F second gas intermediate passage, 32 first isobaric valve shaft, 321 engaging portion, 322 Bearing portion, 33 Second isobaric valve shaft, 33A Through hole, 34 Pilot gas chamber, 35 First isobaric pressure member, 351 Elastic member, 351A Base portion, 351B Protruding portion, 352 Support member, 353 Fixing portion, 354 Press part, 36 2nd isobaric pressure member, 371 1st soft valve body, 372 1st hard valve body, 381 2nd soft valve body, 382 2nd hard valve Body, 382A taper surface, 41 coil spring, 43 valve seat, 44 valve body fixing part, 46 fixing part, 47 O-ring, 48 fixing part, 5 mixing part, 51 merger, 51A first gas flow path, 51B second Gas flow path, 52 merge chamber, 53 mixing ratio adjuster, 6 flow rate adjusting valve, 91 first pipe, 92 second pipe, 93 third pipe, 94 fourth pipe, 95 fifth pipe, 96 sixth pipe, 97 7th piping, 98 8th piping, 99 9th piping, A 1st gas, B 2nd gas.

Claims (5)

A pilot pressure reducing valve that discharges by reducing the pressure of the pilot gas flowing into the pilot pressure;
An isobaric valve that is connected to the pilot pressure reducing valve and discharges the pressure of the first gas and the second gas introduced to be equal to each other based on the pilot pressure of the pilot gas discharged from the pilot pressure reducing valve. When,
A mixing unit that flows in the first gas and the second gas discharged from the isobaric valve, mixes and discharges the first gas and the second gas, and
The pilot pressure reducing valve is
A pilot housing;
A pilot valve shaft disposed in the pilot housing and capable of reciprocating in an axial direction;
A second pilot housing disposed within the pilot housing and fixed to the pilot housing;
A pilot seal member disposed in contact with an outer surface of the pilot valve shaft and an inner surface of the pilot housing, and maintaining airtightness between the pilot valve shaft and the pilot housing;
A pilot pressing member that is disposed in contact with the pilot valve shaft and presses the pilot valve shaft in an axial direction;
A pilot valve body installed on the pilot valve shaft,
When the pilot valve shaft reciprocates in the axial direction, a state where the pilot valve body and the second pilot housing are in contact with each other and a state where they are separated from each other are realized,
The pilot housing is formed with a pilot inflow passage through which the pilot gas flows in and a pilot outflow passage through which the pilot gas reduced to the pilot pressure flows out,
In the state where the pilot valve body and the second pilot housing are in contact with each other,
A first pressure space surrounded by the pilot valve shaft, the pilot housing and the second pilot housing and connected to the pilot inflow passage;
A second pressure space disposed on the opposite side of the first pressure space as viewed from the pilot valve body and connected to the pilot outflow passage;
A third pressure space disposed on the opposite side of the first pressure space as viewed from the pilot seal member and in contact with an end of the pilot valve shaft;
The third pressure space and the second pressure space communicate with each other,
The gas mixer, wherein the pilot seal member is fixed to the pilot housing. The isobaric valve is
An isobaric housing;
A first isobaric valve shaft disposed in the isobaric housing and capable of reciprocating in an axial direction;
A second isobaric valve shaft disposed in the isobaric housing and capable of reciprocating in an axial direction;
The first isobaric valve shaft is disposed in the isobaric housing and forms part of a wall surface of a pilot gas chamber, which is a space connected to the pilot pressure reducing valve, and contacts the first isobaric valve shaft. A first isobaric pressing member that presses in the axial direction;
A second part disposed in the isobaric housing, constituting another part of the wall surface of the pilot gas chamber, and contacting the second isobaric valve shaft to press the second isobaric valve shaft in the axial direction. An isobaric pressing member;
A first soft valve body installed on the first isobaric valve shaft;
A second soft valve body installed on the second isobaric valve shaft;
A first hard valve body installed so as to be reciprocally movable in the axial direction with respect to the first isobaric valve shaft;
A second hard valve body installed so as to be reciprocable in the axial direction with respect to the second isobaric valve shaft,
In the isobaric housing,
A first gas inflow path through which the first gas flows;
A first gas discharge path through which the first gas is discharged;
A first gas intermediate path connecting the first gas inflow path and the first gas discharge path;
A second gas inflow path through which the second gas flows;
A second gas discharge path through which the second gas is discharged;
A second gas intermediate path connecting the second gas inflow path and the second gas discharge path is formed;
A first soft valve element is disposed at a connection portion between the first gas inflow path and the first gas intermediate path;
A first rigid valve body is disposed at a connection portion between the first gas intermediate passage and the first gas discharge passage;
A second soft valve element is disposed at a connection portion between the second gas inflow path and the second gas intermediate path;
2. The gas mixer according to claim 1, wherein a second hard valve body is disposed at a connection portion between the second gas intermediate path and the second gas discharge path. The first isobaric pressing member and the second isobaric pressing member are
An elastic member;
Made of a material having higher rigidity than the elastic member, and a support member that supports the elastic member,
The elastic member is
A base portion having a disk shape;
A projecting portion that is disposed so as to surround the outer periphery of the base portion and projects in a direction in which the pilot gas chamber expands
The gas mixer according to claim 2, wherein the base portion is supported by the support member over the entire area. The mixing unit includes:
The mixing ratio of the first gas and the second gas discharged from the isobaric valve is adjusted, and the first gas and the second gas are discharged from the first gas channel and the second gas channel, respectively. A mixing ratio adjuster;
A cross-sectional area connected to the first gas flow path and the second gas flow path and perpendicular to the direction in which the first gas and the second gas flow is more than that of the first gas flow path and the second gas flow path. A gas mixer according to any one of claims 1 to 3, comprising a merger having a large merge chamber.   The discharge direction of the first gas from the first gas flow path to the merger is along the discharge direction of the second gas from the second gas flow path to the merger. Item 5. A gas mixer according to Item 4.

Images