JP2017113668A - Filter device in gas control unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter device which is disposed in a gas control unit in which the opposite side surface of a valve seat 22 in a valve chamber 21 formed within a casing 1 is open, the open surface is closed by a lid plate 15 attached to the casing and a packing 16 is mounted to the surface of the casing side of the lid plate and where a filter having a finer mesh as much as possible can be mounted to the casing without hindrance.SOLUTION: In a filter device,: a part of a gas passage between a valve chamber 21 and a gas inlet 11 is constituted in an opening passage part 17 whose one side surface is an open surface closed with a lid plate 15; a filter 6 is mounted to a casing 1 so as to cross the opening passage part 17 through the open surface of the opening passage part 17; the filter 6 is constituted by a net-like filter body 61 and a resin outer frame 62 coating the surrounding of the filter body; and a bead 16a pressing the outer frame 62 by being contact with the side of the lid plate 15 side of the outer frame 62 is formed on the packing 16.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a gas control unit in which one or more valves for controlling the flow of gas from a gas inlet to a gas outlet are incorporated in a casing having a gas inlet and a gas outlet. The present invention relates to a filter device in a gas control unit provided for removing foreign substances.

  2. Description of the Related Art Conventionally, as this type of filter device, a device in which a wire mesh filter formed in a cap shape is attached to a gas inlet is known (for example, see Patent Document 1). In general, in the gas control unit, the surface opposite to the valve seat of the valve chamber of the upstream end valve closest to the gas inlet formed in the casing is open, and this open surface is attached to the casing. A packing for sealing the space between the cover plate and the casing is mounted on the surface of the cover plate on the casing side.

  By the way, in order to surely prevent foreign matter from adhering to the valve seat and the valve body and clogging of the orifice in the casing, it is necessary to make the mesh of the filter considerably fine. For that purpose, the metal wire which becomes the origin of the wire mesh which comprises a filter must be made very thin. However, with this, the rigidity of the filter is insufficient, the shape of the filter tends to collapse, and it becomes difficult to attach the filter to the gas inlet. Therefore, in order to be able to attach a filter to the gas inlet, the mesh of the filter cannot be made finer than a certain degree.

JP 2010-101502 A

  This invention makes it the subject to provide the filter apparatus in the gas control unit which enabled it to mount | wear a casing with a fine mesh as much as possible in view of the above point, without trouble.

  In order to solve the above problems, the present invention is formed in a casing having one or more valves for controlling the flow of gas from the gas inlet to the gas outlet in a casing having a gas inlet and a gas outlet. The surface opposite to the valve seat of the valve chamber of the upstream end valve closest to the gas inlet is opened, this open surface is closed with a cover plate attached to the casing, and the cover side surface of the cover plate is covered with the cover. In a filter device provided in a gas control unit equipped with a seal for sealing between a plate and a casing to remove foreign substances in gas flowing from a gas inlet, a valve chamber of a valve at the upstream end and a gas inlet A part of the gas passage between is formed in an open passage portion whose surface located on the same side as the open surface is an open surface closed by the lid plate, and the filter is opened so as to intersect the open passage portion aisle The filter is composed of a mesh-like filter main body and a resin outer frame covering the periphery of the filter main body, and is attached to the packing on the side of the cover plate side of the outer frame of the filter. A bead that contacts and presses the outer frame is formed.

  According to the present invention, even if the rigidity of the filter main body is reduced by making the mesh fine, the outer frame ensures the rigidity of the entire filter. Therefore, even if the mesh of the filter main body is made as fine as possible, the filter can be securely attached to the casing so as to cross the open passage portion without breaking its shape. In addition, since the side of the outer frame on the lid plate side is elastically pressed by a bead formed on the packing, even if the resin outer frame sags due to the creep phenomenon, there is no gap between the outer frame and the bead. It does not occur and foreign matter does not enter through this gap.

The perspective view which shows the gas control unit which comprises the filter apparatus of embodiment of this invention. FIG. 2 is a schematic cross-sectional view of the gas control unit of FIG. 1. The expanded sectional view of the principal part of the gas control unit of FIG. The cutting top view cut | disconnected by the IV-IV line of FIG. The perspective view of the decomposition | disassembly state of the principal part of the gas control unit of FIG.

  1 and 2 show a gas control unit including a filter device according to an embodiment of the present invention. The gas control unit includes a casing 1 having a gas inlet 11 and a gas outlet 12, a first electromagnetic valve 2 and a second electromagnetic valve 3 as valves for controlling the flow of gas from the gas inlet 11 to the gas outlet 12. A zero governor system incorporating a main governor valve 4 and a control governor valve 5 is used.

  The first electromagnetic valve 2 is a valve at the upstream end closest to the gas inlet 11, and a valve chamber 21 that is always in communication with the gas inlet 11 and a valve body 23 that can be seated on a valve seat 22 on the lower surface of the valve chamber 21. And a solenoid 24 for opening and closing the valve body 23. The second electromagnetic valve 3 includes a valve chamber 31 that communicates with a pressure chamber 45 described later via a communication passage 45 a, and a valve body 33 that can be seated on a valve seat 32 on the lower surface of the valve chamber 31. In the valve seat 32, the gas passage 13 in the casing 1 that communicates with the valve chamber 21 through the valve hole 22 a formed in the valve seat 22 of the first electromagnetic valve 2 is communicated with the valve chamber 31 of the second electromagnetic valve 3. A valve hole 32a with an orifice is formed. The second solenoid valve 3 is not provided with a solenoid, but the second solenoid valve 3 is opened simultaneously with the first solenoid valve 2 when the solenoid 24 of the first solenoid valve 2 is energized.

  The main governor valve 4 always communicates with a valve chamber 41 located at the downstream end of the gas passage 13, a valve body 43 that can be seated on a valve seat 42 on the lower surface of the valve chamber 41, and the gas outlet 12. A diaphragm 44 that covers the lower surface of the outlet chamber 14 that communicates with the valve chamber 41 through the formed valve hole 42 a and a pressure chamber 45 that is defined below the diaphragm 44 are provided. The valve body 43 is connected to the diaphragm 44 via the valve shaft 43a, and is further urged downward by the spring 46.

  The control governor valve 5 has an upper surface of the valve chamber 51 to which a valve chamber 51 that is always in communication with the outlet chamber 14 via the communication passage 14 a and a valve body 53 that can be seated on the valve seat 52 on the lower surface of the valve chamber 51 is attached. A covering diaphragm 54 and a control pressure chamber 55 defined on the upper side of the diaphragm 54 are provided. The valve seat 52 is formed with a valve hole 52 a that communicates with the pressure chamber 45 via the communication passage 45 b, and the valve body 53 is urged downward by a spring 56.

  The valve chambers 21 and 31 of both the first and second electromagnetic valves 2 and 3 and the valve chamber 41 of the main governor valve 4 are formed in the casing 1. The upper surfaces of the valve chambers 21, 31, 41 opposite to the valve seats 22, 32, 42 are open, and the open surfaces are closed by a cover plate 15 attached to the casing 1. The valve chamber 51 of the control governor valve 5 is formed in the lid plate 15. Further, a packing 16 that seals between the cover plate 15 and the casing 1 is attached to the surface of the cover plate 15 on the casing 1 side, that is, the lower surface, as shown in FIGS.

Here, the pressure (primary pressure) of the gas inlet 11 is P1, the pressure (secondary pressure) of the gas outlet 12 is P2, the internal pressure of the pressure chamber 45 is P3, the internal pressure of the control pressure chamber 55 is P4, and the main governor valve 4 The biasing force of the spring 46 is F1, the biasing force of the spring 56 of the control governor valve 5 is F2, the effective pressure receiving area of the diaphragm 44 of the main governor valve 4 is Sa, the area of the valve hole 42a of the main governor valve 4 is Sb, and the control governor. When the effective pressure receiving area of the diaphragm 54 of the valve 5 is Sc and the area of the valve hole 52a of the control governor valve 5 is Sd, the main governor valve is opened in the state where both the first and second electromagnetic valves 2 and 3 are opened. On the diaphragm 44 of No. 4, a pressing force of P3 · Sa + P2 · Sb acts on the upper side, and a pressing force of P2 · Sa + P1 · Sb + F1 acts on the lower side to balance both the pressing forces. Therefore,
P3 · Sa + P2 · Sb = P2 · Sa + P1 · Sb + F1 (1)
And the following equation from the equation (1):
P3 = P2 + (P1-P2) Sb / Sa + F1 / Sa (2)
Is obtained. Here, since Sb << Sa, the second term on the right side of the equation (2) can be regarded as zero.
P3 = P2 + F1 / Sa (3)
Is established.

The diaphragm 54 of the control governor valve 5 has a pressing force of P2 · (Sc−Sd) + P3 · Sd acting on the upper side and a pressing force of P4 · Sc + F2 acting on the lower side to balance both the pressing forces. . Therefore,
P2 · (Sc−Sd) + P3 · Sd = P4 · Sc + F2 (4)
Is established. Substituting (3) into (4) and rearranging, the following equation:
P2 · Sc + F1 · Sd / Sa = P4 · Sc + F2 (5)
become. Here, since Sd << Sa, the second term on the left side of the equation (5) can be regarded as zero.
P2 = P4 + F2 / Sc (6)
Is established. Accordingly, the secondary pressure P2 is proportional to the internal pressure P4 of the control pressure chamber 45 with a slope of 1. If the control pressure chamber 55 is opened to the atmosphere, for example, and the internal pressure P4 is set to atmospheric pressure, the secondary pressure P2 is maintained at a constant pressure obtained by adding F2 / Sc to atmospheric pressure.

  Although the gas control unit has been described above, the gas control unit is provided with a filter device for removing foreign matters such as dust in the gas flowing in from the gas inlet 11. Hereinafter, this filter device will be described in detail with reference to FIGS.

  A part of the gas passage between the valve chamber 21 of the first electromagnetic valve 2 that is the upstream end valve and the gas inlet 11 is closed by the cover plate 15 on the upper surface located on the same side as the open surface of the valve chamber 21. It is comprised by the open channel | path part 17 used as the open surface. The filter 6 is attached to the casing 1 from above through the open surface of the open passage portion 17 so as to intersect the open passage portion 17. In the present embodiment, the open passage portion 17 is continuous with the valve chamber 21, but it is also possible to provide the open passage portion in a portion away from the valve chamber 21.

  The filter 6 includes a square mesh filter main body 61 and a resin outer frame 62 that covers the four sides around the filter main body 61. On the other hand, three sides of the outer periphery 62 of the filter 6, that is, the lower side and both sides in the lateral direction, are formed on the three peripheral surfaces except the open surface (upper surface) side of the open passage portion 17, that is, the lower surface and the lateral side surfaces. A fitting groove 17a to be fitted is formed. Thus, the filter 6 is pushed into the open passage portion 17 from above with the cover plate 6 removed, so that the three outer frames 62 of the filter 6 are inserted into the mounting grooves 17a formed on the three sides of the open passage portion 17. The filter 6 is attached to the casing 1 so as to intersect the open passage portion 17 with the side fitted. Further, the packing 16 on the lower surface of the cover plate 15 is formed with a bead 16 a that abuts the side (upper side) of the outer frame 62 of the filter 6 on the side of the cover plate 15 and presses the outer frame 62. In FIG. 3, the free state of the bead 16a is indicated by a two-dot chain line. The filter main body 61 is not limited to a wire mesh but may be a resin mesh.

  According to the above configuration, even if the rigidity of the filter main body 61 is reduced by making the mesh finer, the outer frame 62 ensures the rigidity of the entire filter 6. Therefore, even if the mesh of the filter body 61 is made as fine as possible, the filter 6 can be securely attached to the casing 1 without breaking its shape so as to intersect the open passage portion 17. In addition, since the upper side of the outer frame 62 is elastically pressed by the bead 16a, even if the resin outer frame 62 sags due to a creep phenomenon, there is no gap between the outer frame 62 and the bead 16a. Foreign matter does not enter through this gap.

  The mounting groove 17a on the side surface of the open passage portion 17 has a draft angle slightly inclined outward in the lateral direction. Therefore, the lower half of the side portion of the outer frame 62 of the filter 6 is slightly inclined inward in the lateral direction, and the side portion is inserted into the mounting groove 17a on the side surface of the open passage portion 17 from above. It is easy. On the other hand, the upper half of the side portion of the outer frame 62 is a straight portion 62b that extends straight upward from a stepped portion 62a that projects slightly outward in the lateral direction with respect to the upper end of the lower half. The straight portion 62b is press-fitted into the upper half of the mounting groove 17a on the side surface of the open passage portion 17, so that the filter 6 is mounted on the casing 1 without play.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to this. For example, the above embodiment is a filter device provided in a zero governor type gas control unit, but the present invention can be similarly applied to a filter device provided in a gas control unit other than the zero governor type.

  DESCRIPTION OF SYMBOLS 1 ... Casing, 11 ... Gas inlet, 12 ... Gas outlet, 15 ... Cover plate, 16 ... Packing, 16a ... Bead, 17 ... Opening passage part, 2 ... 1st solenoid valve (upstream end valve), 21 ... Valve chamber , 6 ... Filter, 61 ... Filter body, 62 ... Outer frame.

Claims (1)

One or more valves for controlling the flow of gas from the gas inlet to the gas outlet are incorporated in a casing having a gas inlet and a gas outlet, and the valve chamber of the valve at the upstream end closest to the gas inlet formed in the casing The surface opposite to the valve seat is opened, this open surface is closed by a cover plate attached to the casing, and a packing that seals between the cover plate and the casing is attached to the casing side surface of the cover plate In the filter device provided for removing foreign substances in the gas flowing in from the gas inlet to the gas control unit,
A portion of the gas passage between the valve chamber of the upstream end valve and the gas inlet is configured as an open passage portion in which a surface located on the same side as the open surface is an open surface closed by the lid plate. A filter is attached to the casing through the open surface of the open passage portion so as to intersect the open passage portion, and the filter is composed of a net-like filter main body and a resin outer frame covering the periphery of the filter main body, and the packing Further, a bead for pressing the outer frame in contact with the side of the outer frame of the filter on the cover plate side is formed.

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