Gas manifold

Abstract

To surely prevent seal failure in closing a solenoid valve 533 even in using a partition plate 52 composed of a roll material, in a gas manifold including a nozzle block 51 having a plurality of nozzle chambers 511 opened forward, a partition plate 52 covering the nozzle chambers 511 from a front part, and a valve block 53 having a gas inflow chamber 531 recessed at a front part, and provided with a plurality of solenoid valves 533 to control gas supply to the plurality of nozzle chambers 511 through a plurality of communication holes 521 formed on the partition plate 52.SOLUTION: Valve seats 535 which are provided with valve holes 535a facing each of through holes 521 of a partition plate 52 and on which valve elements 533b of solenoid valves 533 can sit, are integrally formed on a valve block 53 in a state of being joined to upper and lower wall portions of a gas inflow chamber 531 through upper and lower bridge portions 535b projecting at upper and lower parts of the valve seat.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a gas manifold that supplies fuel gas to a burner unit that is made up of a plurality of burners arranged side by side in the horizontal direction, each having a gas inlet at the lower front end. [Background technology]

[0002] Conventionally, as an example of this type of gas manifold, Patent Document 1 discloses a nozzle block having a plurality of nozzle chambers that are open forward and arranged side by side in the horizontal direction, with nozzles that communicate with each nozzle chamber and face the gas inlet ports of each burner provided on the outer surface of the rear wall of each nozzle chamber; a partition plate that is provided on the front side of the nozzle block so as to cover the plurality of nozzle chambers from the front and has a plurality of through holes that communicate with each of these nozzle chambers; and a valve block that is provided on the front side of the partition plate and has a gas inlet chamber that is recessed forward, with solenoid portions of a plurality of electromagnetic valves attached to the front wall of the gas inlet chamber to control the gas supply from the gas inlet chamber to the plurality of nozzle chambers via the through holes.

[0003] To reduce costs, it is desirable to use a partition plate made by pressing a roll material. However, even when pressed, the roll material warps due to spring back. Therefore, if a partition plate made of roll material is used, and the valve element of a solenoid valve is brought into contact with the partition plate to open and close the through-hole, that is, if the partition plate also serves as the valve seat of the solenoid valve, poor sealing is likely to occur when the solenoid valve is closed.

[0004] Therefore, in the device described in Patent Document 1, the nozzle block is provided with a rib that extends laterally and is positioned on the inner surface of the rear wall of each nozzle chamber, thereby increasing the bending rigidity of the nozzle block. Patent Document 1 also describes that by fastening the valve block to the front of the nozzle block with a partition plate made of roll material sandwiched between them, warping of the partition plate is corrected in accordance with the high rigidity of the nozzle block, and poor sealing when the solenoid valve is closed can be improved. However, in reality, poor sealing when the solenoid valve is closed cannot be sufficiently improved. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-96363 Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above, an object of the present invention is to provide a gas manifold that can reliably prevent poor sealing when the solenoid valve is closed, even when a partition plate made of roll material is used. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides a gas manifold for supplying fuel gas to a burner unit comprising a plurality of burners arranged side by side in the horizontal direction, each having a gas inlet at a lower front end, the manifold comprising: a nozzle block having a plurality of nozzle chambers arranged side by side in the horizontal direction and opening forward, with nozzles provided on the outer surface of the rear wall of each nozzle chamber, which communicate with each nozzle chamber and face the gas inlet of each burner; a partition plate provided on the front side of the nozzle block so as to cover the plurality of nozzle chambers from the front, with a plurality of through holes formed therein and communicating with each of these nozzle chambers; and a valve block provided on the front side of the partition plate, which has a gas inlet chamber recessed toward the front, with solenoid portions of a plurality of solenoid valves attached to the front wall of the gas inlet chamber to control the supply of gas from the gas inlet chamber to the plurality of nozzle chambers via the through holes, the valve block being characterized in that valve seats, each with a valve hole facing each through hole in the partition plate and on which the valve element of each solenoid valve can be seated, are formed integrally with the valve block, with the valve seats joined to the upper and lower wall portions of the gas inlet chamber via upper and lower bridge portions projecting above and below the valve seat.

[0008] According to the present invention, by using a partition plate made of roll material, even if the partition plate is warped, the valve disc reliably contacts the valve seat, which is formed integrally with the valve block and has ensured surface precision, when the solenoid valve is closed. Therefore, sealing failure when the solenoid valve is closed can be reliably prevented.

[0009] The valve block can be die-cast using a female mold that forms the outer surface of the front wall and the outer surface of the peripheral wall of the gas inlet chamber and has a core mold portion that reaches the inner surface of the valve seat through holes for inserting the valve bodies of the solenoid valves opened in the front wall of the gas inlet chamber, and a male mold that forms the inner surface of the front wall and the peripheral wall of the gas inlet chamber and reaches the inner surface of the front wall of the gas inlet chamber by passing beside the valve seat and bridge portion. However, during die-casting of the valve block, molten metal that seeps into the mating portion between the core mold portion of the female mold and the male mold will produce flash.

[0010] Therefore, in the present invention, it is desirable that the outer diameter of each valve seat is smaller than the diameter of the hole for inserting the valve disc of each solenoid valve, which is opened in the front wall of the gas inlet chamber. In this way, when a tool is inserted through the valve disc insertion hole to finish the inner surface of the valve seat after die-casting of the valve block, the burrs can be removed with this tool, which is advantageous in reducing processing costs. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a cutaway side view of a combustion device equipped with a gas manifold according to an embodiment of the present invention; [Figure 2] FIG. 2 is a perspective view of the gas manifold of the embodiment as viewed obliquely from the rear. [Figure 3] FIG. 2 is a perspective view of the gas manifold of the embodiment as viewed obliquely from the front. [Figure 4] FIG. 2 is an exploded perspective view of the gas manifold according to the embodiment, as viewed obliquely from the front. [Figure 5] FIG. 2 is a perspective view of a nozzle block that constitutes the gas manifold of the embodiment, as viewed obliquely from the rear. [Figure 6] FIG. 6 is a cross-sectional plan view of the nozzle block taken along line VI-VI in FIG. 5. DETAILED DESCRIPTION OF THE INVENTION

[0012] Referring to FIG. 1, reference numeral 1 denotes a combustion housing, and a burner unit is disposed within the combustion housing 1, the burner unit being composed of multiple burners 2 arranged side by side in the horizontal direction (perpendicular to the plane of FIG. 1). Each burner 2 has, at its upper end (not shown), a lean flame port for ejecting a lean mixture with a fuel concentration leaner than the stoichiometric air-fuel ratio, and a rich flame port for ejecting a rich mixture with a fuel concentration richer than the lean mixture. At its lower front end, the burner is configured as a known lean-rich burner having a first gas inlet 21 connected to the lean flame port and a second gas inlet 22 connected to the rich flame port above the first gas inlet 21. Also disposed within the combustion housing 1 are a first burner unit for heating a hot water heat exchanger installed above the combustion housing, and a second burner unit for heating a heating heat exchanger.

[0013] An air supply chamber 4, partitioned by a partition plate 3 from the area where the burner units are located, is provided in the lower part of the combustion housing 1. Air is supplied to the air supply chamber 4 from a fan (not shown). A portion of the air supplied to the air supply chamber 4 is supplied to the area where the burner units are located through numerous small holes (not shown) formed in the partition plate 3 as secondary air for combustion. An upright plate portion 3a is provided at the front end of the partition plate 3. A gas manifold 5 according to an embodiment of the present invention, which supplies fuel gas to both the first and second burner units, is located in front of the upright plate portion 3a. A primary air chamber 4a connected to the air supply chamber 4 is defined between the upright plate portion 3a and the gas manifold 5. The upright plate portion 3a has openings that correspond to the first and second gas inlets 21 and 22 of each burner 2, respectively. Primary air for combustion is supplied to both gas inlets 21 and 22 through the primary air chamber 4a.

[0014] The gas manifold 5 includes a rear nozzle block 51, a middle partition plate 52, and a front valve block 53. It also includes a first packing 54 that seals between the nozzle block 51 and the partition plate 52, and a second packing 55 that seals between the partition plate 2 and the valve block 53. Details thereof will be described below with reference to Figures 2 to 4.

[0015] The nozzle block 51 is a die-cast product and has four nozzle chambers 511, #1 to #4, which are open forward and arranged side by side in the horizontal direction. The nozzle chambers 511, #1 to #3, correspond to the first burner unit and are adjacent to each other in the horizontal direction, while the nozzle chamber 511, #4, corresponds to the second burner unit and is separated from the nozzle chamber 511, #3. On the outer surface of the rear wall of each of these nozzle chambers 511, a plurality of first and second nozzles 512, 513 are arranged side by side in the horizontal direction, facing the first and second gas inlets 21, 22 of each burner 2. The nozzle block 51 further has a plurality of bosses 514 located on both the upper and lower outer sides of the nozzle chambers 511, #1 on one lateral side, and #4 on the other lateral side. Each boss 514 has a screw hole 514a.

[0016] The partition plate 52 is made of a roll material and is provided on the front side of the nozzle block 51 so as to cover the nozzle chambers 511 #1 to #4 from the front. Four through holes 521 that communicate with the nozzle chambers 511 #1 to #4, respectively, are formed in the partition plate 52. In addition, a plurality of mounting holes 522 that correspond to the screw holes 514a are formed on both the top and bottom sides and both lateral sides of the partition plate 52.

[0017] The valve block 53 is a die-cast product, and as shown in Figures 4 and 5, has a horizontally elongated gas inlet chamber 531 recessed forward and an inlet pipe portion 532 extending downward from the lower end of the central portion of the gas inlet chamber 531. Fuel gas is supplied to the gas inlet chamber 531 through the inlet pipe portion 532 from a gas pipe (not shown). Attached to the front wall of the gas inlet chamber 531 are solenoid portions 533a of four solenoid valves 533 that respectively control the gas supply from the gas inlet chamber 531 to the nozzle chambers 511 #1 to #4 via four through-holes 521 formed in the partition plate 52. The valve block 53 also has a plurality of mounting holes 534 formed on both the top and bottom outer sides and both lateral outer sides of the gas inlet chamber 531, corresponding to the screw holes 514a.

[0018] The valve block 53 is further provided with four valve seats 535, each with a valve hole 535a facing each through hole 521 in the partition plate 52, on which the valve element 533b of each solenoid valve 533 can be seated, corresponding to the four through holes 521. Here, each valve seat 535 is formed integrally with the valve block 53, and is joined to the upper and lower wall portions of the gas inlet chamber 531 via upper and lower bridge portions 535b extending above and below the valve seat 535. Note that the valve seats 535 located near each of the lateral ends of the gas inlet chamber 531 are joined not only by the upper and lower bridge portions 535b but also by their outer lateral peripheral edges to the end wall portions of each lateral end of the gas inlet chamber 531. Furthermore, holes 536 for inserting the valve elements 533b of each solenoid valve 533 are formed in the front wall portion of the gas inlet chamber 531 of the valve block 53.

[0019] The first packing 54 is interposed between the front surface of the nozzle block 51, i.e., the front end surfaces of the peripheral walls of the nozzle chambers 511 of #1 to #4, and the rear surface of the partition plate 52, to airtightly seal each nozzle chamber 511. The second packing 55 is interposed between the rear surface of the valve block 53, i.e., the rear surface of the peripheral portion of the gas inflow chamber 531, and the front surface of the partition plate 52, to airtightly seal the gas inflow chamber 531. The second packing 55 is also provided with sealing portions 551 interposed between the rear surface of each valve seat 535 and the front surface of the peripheral edge of each through-hole 521 of the partition plate 52.

[0020] Positioning protrusions 515 are provided on the front surface of the nozzle block 51, located at one lateral outer upper portion of the #1 nozzle chamber 511 and the other lateral outer upper portion of the #4 nozzle chamber 511, and fit into positioning holes 541 formed in the first packing 54 at corresponding positions and positioning holes 523 formed in the partition plate 52 at corresponding positions, thereby positioning the first packing 54 and the partition plate 52. In addition, positioning protrusions 537 are provided on the rear surface of the valve block 53, located at the lower portions of both lateral outer sides of the gas inflow chamber 531, and fit into positioning holes 552 formed in the second packing 55 at corresponding positions and positioning holes 524 formed in the partition plate 52 at corresponding positions, thereby positioning the second packing 54 and the partition plate 52. Then, with first gasket 54, partition plate 52, and second gasket 55 sandwiched between nozzle block 51 and valve block 53, mounting screws 56 are passed through mounting holes 534 of valve block 53 and mounting holes 522 of partition plate 52 and tightened into screw holes 514a, thereby fastening valve block 53 to nozzle block 51 and assembling gas manifold 5.

[0021] In this embodiment, as described above, the valve seat 535 on which the valve element 533b of each solenoid valve 533 sits is formed integrally with the valve block 53, which makes it easy to ensure the surface precision of the valve seat 53. Therefore, by using the partition plate 52 made of roll material, even if the partition plate 52 is warped, the valve element 533b reliably contacts the valve seat 535 when the solenoid valve 533 is closed. As a result, it is possible to reliably prevent poor sealing when the solenoid valve 533 is closed.

[0022] The valve block 53 can be die-cast using a female mold that forms the outer surface of the front wall and the outer surface of the peripheral wall of the gas inlet chamber 531 and has a core portion that passes through the valve element insertion hole 536 in the front wall of the gas inlet chamber 531 and reaches the inner surface of the valve seat 535 and bridge portion 535b, and a male mold that forms the inner surface of the front wall and the inner surface of the peripheral wall of the gas inlet chamber 531 and passes beside the valve seat 535 and bridge portion 535b and reaches the inner surface of the front wall of the gas inlet chamber 531. However, during die-casting of the valve block 53, molten metal seeping into the mating portion between the core portion of the female mold and the male mold will create flash a, as shown by the phantom line in Figure 6.

[0023] In this embodiment, the outer diameter of each valve seat 535 is smaller than the diameter of the valve disc insertion hole 536. This allows the burrs a to be removed when a tool is inserted through the valve disc insertion hole 536 to finish the inner surface of the valve seat 535 after die-cast molding of the valve block 53. This eliminates the need for a special step to remove the burrs a, thereby reducing processing costs.

[0024] Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited thereto. For example, in the above embodiment, the present invention is applied to the gas manifold 5 of a combustion device for hot water supply and heating, but the present invention can also be applied to gas manifolds of combustion devices dedicated to hot water supply or other combustion devices. [Explanation of symbols]

[0025] 2...burner, 21, 22...gas inlet, 5...gas manifold, 51...nozzle block, 511...nozzle chamber, 512, 513...nozzle, 52...partition plate, 521...through hole, 53...valve block, 531...gas inlet chamber, 533...solenoid valve, 533a...solenoid part, 533b...valve body, 535...valve seat, 535a...valve hole, 535b...bridge part, 536...hole for inserting valve body.

Claims

1. A gas manifold that supplies fuel gas to a burner unit that is configured by arranging a plurality of burners in parallel in the horizontal direction, each having a gas inlet at a lower front end thereof, a nozzle block having a plurality of nozzle chambers that are open forward and arranged side by side in the horizontal direction, with nozzles that communicate with each nozzle chamber and face the gas inlet ports of each burner provided on the outer surface of the rear wall of each nozzle chamber; a partition plate that is provided on the front side of the nozzle block so as to cover the plurality of nozzle chambers from the front and has a plurality of through holes that communicate with each of these nozzle chambers; and a valve block that is provided on the front side of the partition plate and has a gas inlet chamber that is recessed forward, with solenoid portions of a plurality of electromagnetic valves attached to the front wall of the gas inlet chamber to control gas supply from the gas inlet chamber to the plurality of nozzle chambers via the through holes, A gas manifold characterized in that a valve seat on which the valve body of each solenoid valve can be seated, with valve holes facing each through hole of the partition plate, is formed integrally with the valve block, and is joined to the upper and lower wall portions of the gas inlet chamber via upper and lower bridge portions extending above and below the valve seat.

2. 2. The gas manifold according to claim 1, wherein the outer diameter of each of the valve seats is smaller than the diameter of a hole formed in the front wall of the gas inlet chamber for inserting a valve body of each of the electromagnetic valves.

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