JP2007222936A - Method of plasma arc welding, and method for manufacturing micro reactor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of plasma arc welding, which method can carry out welding in the state that several plate members are uprightly arranged on a plate member, particularly even in the state that the interval between the plate members to be uprightly arranged on the plate member is narrow, and further to provide a method for manufacturing a micro reactor. <P>SOLUTION: Respective side walls and partition walls 724 of a frame body 723 are brought into contact with one side surface of a bottom plate 722 in the state that the respective side walls and partition walls 724 are uprightly arranged by overlapping the bottom plate 722 on the frame body 723 so as to cover one opening of the frame body 723 with the bottom plate 722. Then, the tip end of a welding torch 701 is opposed to the other surface of the bottom plate 722 on the reverse side of the frame body 723 and the partition walls 724 with respect to the bottom plate 722. Then, a plasma arc 711 are jetted from the welding torch 701. Then, the welding torch 701 are moved with respect to the bottom plate 722, the frame body 723, and the partition walls 724 so as to trace the frame body 723 and the partition walls 724 along the edge portions of the bottom plate 722 by means of the plasma arc 711 at the tip end of the welding torch 701. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a plasma arc welding method for welding workpieces using a plasma arc, and a reactor manufacturing method using the plasma arc welding method.

  Fuel cells are attracting attention as power sources for small electronic devices because they are small but have high energy utilization efficiency. When hydrogen is supplied to the fuel cell, electric energy can be obtained, but hydrogen can be obtained by reforming liquid fuel such as alcohols with a microreactor. In order to mount the microreactor on a small electronic device, it is necessary to further reduce the size of the microreactor. For example, as described in Patent Document 1, a small microreactor is manufactured by joining substrates having grooves formed therein. Has been.

However, in the case of a microreactor in which substrates are joined together, the volume of the entire microreactor excluding the volume of the groove may be larger than the volume of the groove. For this reason, the heat capacity of the microreactor itself increases, and the energy utilization efficiency decreases. Therefore, there is an attempt to assemble a microreactor by welding a very thin sheet-like plate material by a fine processing technique. When assembling the microreactor, as shown in FIG. 14A, the thin plate 901 is welded with the thin plate 902 serving as the outer wall and the thin plate 903 serving as the inner wall arranged side by side through the brazing material 904. In FIG. 14, the space between the thin plates 902 and 903 is a flow path.
JP 2005-132712 A

Since the brazing material 904 can be melted by being heated from the inner surface 901a side of the thin plate 901 to the melting point of the brazing material 904 or higher as indicated by an arrow A, the thin plates 902 and 903 can be welded to the inner surface 901a of the thin plate 901. Further, in order to weld the thin plates 902 and 903 welded to the thin plate 901 to the thin plate 907, the brazing material 906 must be heated after the brazing material 906 is provided on the welded portion of the inner surface 907a of the thin plate 907. At this time, the brazing material 906 can be melted by applying heat from the outside of the thin plate 902 while the thin plate 902 serving as the outer wall is in contact with the welded portion of the thin plate 907 as indicated by an arrow B. However, if the thin plate 903 serving as the inner wall comes into contact with the welded portion of the thin plate 907, the thin plate 902 becomes a three-dimensional obstacle and it is difficult to heat the brazing material 906 that binds the thin plate 903 and the thin plate 907. There is a risk of failure.
Accordingly, an object of the present invention is to provide a plasma arc welding method and a microreactor manufacturing method capable of easily welding a standing plate material when welding a plurality of other plate materials on the plate material.

  In order to solve the above problems, the invention according to claim 1 is a plasma arc welding method in which a plate-like second workpiece is erected on one surface of the plate-like first workpiece. In a state where the second workpiece is set up on the first workpiece by ejecting a plasma arc on the surface opposite to the one surface of the first workpiece. It is characterized by welding.

  According to the first aspect of the present invention, for example, even if there is an obstacle or the like near the second workpiece on one surface side of the first workpiece, the first workpiece Since the plasma arc is ejected to the other surface, there is no need to insert a welding torch near the contact portion between the second workpiece and the first workpiece. Therefore, when the second workpiece and the first workpiece are brought into contact with each other, at least one of the second workpiece and the first workpiece can be easily welded without causing a steric hindrance. Such a plasm arc welding method is particularly suitable for manufacturing a small microreactor.

  According to a second aspect of the present invention, in the plasma arc welding method according to the first aspect, an incision is made along the portion where the second workpiece is in contact with the first workpiece. It is formed in a material, and the plasma arc is ejected toward the cut.

  According to the invention which concerns on Claim 2, the energy required for welding can be suppressed by forming a notch in the 1st work material, and distortion of the 1st work material and the 2nd work material is suppressed. Can do.

  According to a third aspect of the present invention, in the plasma arc welding method according to the first aspect, the groove is formed along the location of the one surface where the second workpiece is in contact with the first workpiece. It is formed on the opposite surface of the first workpiece, and the plasma arc is ejected toward the groove.

  According to a fourth aspect of the present invention, in the plasma arc welding method according to the first or third aspect of the present invention, the groove is formed in the first arc so that the second workpiece is along a position where the second workpiece is in contact with the first workpiece. The plasma arc is ejected toward a portion corresponding to the groove in the opposite surface of the first workpiece, which is formed on the one surface of the workpiece.

  According to the invention which concerns on Claim 3, Claim 4 can suppress energy required for welding by forming a groove | channel in the 1st work material, and the 1st work material and the 2nd work material Distortion can be suppressed.

  The invention according to claim 5 is characterized in that, in the plasma arc welding method according to claim 4, the plasma arc is ejected in a state where the second workpiece is fitted in the groove.

  According to the fifth aspect of the invention, the second workpiece can be temporarily fixed to the first workpiece by fitting the second workpiece into the groove.

  The invention according to claim 6 is characterized in that a microreactor is manufactured by using the plasma arc welding method according to any one of claims 1 to 5.

  According to the invention which concerns on Claim 6, a small microreactor can be manufactured.

  The invention according to claim 7 includes a step of stacking the plate material on the frame body so as to cover the opening of the frame body provided with the partition wall on the inner surface with the plate material, and the opposite side of the frame body and the partition wall with respect to the plate material. And a step of welding the frame and the partition wall to the plate material by ejecting a plasma arc to the plate material.

  According to the seventh aspect of the present invention, since the frame body is overlapped on one surface of the plate material and the plasma arc is ejected from the opposite side to the other surface of the plate material, the frame body and the partition wall can be welded to the plate material. Here, even if the frame is small or a partition is provided on the inside of the frame, a plasma arc is ejected to the other surface of the plate, so near the contact portion between the plate and the frame or the frame There is no need to insert a welding torch near the partition abutment. Therefore, a small microreactor can be easily manufactured.

  According to an eighth aspect of the present invention, in the method for manufacturing a microreactor according to the seventh aspect, a notch is formed in the plate material so that the partition wall is in contact with the plate material, and the plasma arc is ejected toward the notch. Then, the partition is welded to the plate.

  According to the invention which concerns on Claim 8, the energy required for welding can be suppressed by forming a notch in a board | plate material, and distortion of a board | plate material, a frame, and a partition can be suppressed.

  The invention according to claim 9 is the microreactor manufacturing method according to claim 7, wherein the groove and the partition face the surface of the plate opposite to the frame so that the frame and the partition are in contact with the plate. The frame body and the partition wall are welded to the plate material by ejecting the plasma arc toward the groove.

  The invention according to claim 10 is the method of manufacturing a microreactor according to claim 7 or 9, wherein a groove is formed on a surface of the plate member on the frame opposite side so that the frame body and the partition wall are in contact with the plate member. Formed and welding the frame body and the partition wall to the plate material by ejecting the plasma arc toward a position corresponding to the groove on the surface of the plate material opposite to the frame body. To do.

  According to the invention which concerns on Claim 9, Claim 10 can suppress energy required for welding by forming a groove | channel in a board | plate material, and can suppress distortion of a board | plate material, a frame, and a partition.

  According to an eleventh aspect of the present invention, in the method for manufacturing a microreactor according to the tenth aspect, the plasma arc is ejected in a state in which the frame body and the partition wall are fitted in the groove.

  According to the invention which concerns on Claim 11, a frame and a partition can be temporarily fixed to a board | plate material by inserting a frame and a partition in a groove | channel.

  According to the present invention, when the second workpiece and the first workpiece are brought into contact, at least one of the second workpiece and the first workpiece is easily welded without causing steric hindrance. And a small microreactor can be easily manufactured.

  Hereinafter, as a best mode for carrying out the present invention, a method of manufacturing a microreactor using a microplasma arc welding method will be described. However, although various technically preferable limitations for implementing the present invention are given to the embodiments described below, the scope of the invention is not limited to the following embodiments and illustrated examples.

First, the welding apparatus will be described with reference to FIG. FIG. 1 is a schematic view showing a cross section of a main part of a welding torch 701 and the like.
As shown in FIG. 1, the welding torch 701 includes a tungsten cathode bar 702, a cylindrical anode nozzle 703 arranged coaxially with the cathode bar 702 at a predetermined interval outward from the cathode bar 702, and an anode nozzle And a cylindrical constraining nozzle 704 disposed coaxially with the cathode bar 702 at a predetermined interval from the outer side 703. An opening 712 corresponding to the tip position of the cathode bar 702 is provided at the tip of the anode nozzle 703, and the tip of the restraining nozzle 704 corresponds to the position of the opening 712 and surrounds the periphery of the opening 712. An opening 713 is provided. The anode nozzle 703 has a shape with a narrowed tip, the restriction nozzle 704 has a shape with a narrowed tip, and the tips of the cathode bar 702, the anode nozzle 703, and the restriction nozzle 704 are directed toward the workpiece 710. Yes.

A plasma gas supply device is connected to the passage 705 between the cathode bar 702 and the anode nozzle 703, plasma gas (for example, Ar) is supplied to the passage 705, and the plasma gas is in an ionized plasma state as will be described later. After that, the plasma arc 711 is discharged from the opening 712. The diameter of the plasma arc 711 can be set by the inner diameter of the opening 712 and the like, and is preferably about the thickness of the frame body 723 and the partition 724 to be welded. A shield gas supply device is connected to the passage 706 between the anode nozzle 703 and the restraining nozzle 704, and a shield gas (for example, a mixture of Ar and H ₂ ) is supplied to the passage 706, and the shield gas is released. In order to prevent the plasma arc 711 from coming into contact with the atmosphere, the plasma arc 711 is emitted from the opening 713 while surrounding the plasma arc 711.

  A main power source 707 is connected between the workpiece 710 and the cathode bar 702, and a low-current pilot arc power source 708 is connected between the cathode bar 702 and the anode nozzle 703.

  In this welding torch 701, when a plasma gas is fed into the passage 705 by the plasma gas supply device and the pilot arc power source 708 is operated, a pilot arc is generated between the cathode bar 702 and the anode nozzle 703. Then, when the main power source 707 is activated, the anode nozzle 703 is water-cooled, and simultaneously the shield gas is supplied to the passage 706 by the shield gas supply device, the converged high-temperature / high-density plasma arc 711 is formed into the cathode bar 702 and the workpiece. It occurs between 710 and 710. The temperature of the plasma arc 711 is higher than the melting point of the workpiece 710 and is about 10000 ° C. to 20000 ° C.

The material of the microreactor will be described with reference to FIG. FIG. 2 is an exploded perspective view of the microreactor.
As shown in FIG. 2, a rectangular thin plate-like top plate 721 and bottom plate 722 and a rectangular frame-like frame body 723 having an upper surface and a lower surface are used as materials for the microreactor. Inside the frame body 723, a thin plate-like partition wall 724 is provided on the inner surface of two of the four sidewalls, and the inside of the frame body 723 is partitioned by the partition wall 724 into a twisted flow path 725. The height of the partition wall 724 is substantially equal to the height of the surrounding frame body 723. All of the top plate 721, the bottom plate 722, the frame body 723, and the partition wall 724 are made of a metal material such as stainless steel (SUS304) that hardly causes a chemical reaction to a substance flowing in the flow path 725. Note that the top plate 721 and the bottom plate 722 are the first workpiece, and each side wall and the partition 724 of the frame 723 are the second workpiece.

  A method for manufacturing a microreactor will be described with reference to FIG. FIG. 3 is a cross-sectional view sequentially illustrating the manufacturing process of the microreactor.

  First, both the top plate 721 and the bottom plate 722 are polished. Next, the partition wall 724 and the frame body 723 are machined by forming the flow path 725 in the rectangular parallelepiped metal lump by die-sinking electric discharge machining. In addition, when the thickness of each side wall of the top plate 721, the bottom plate 722, the partition 724, and the frame body 723 is 0.1 to 0.2 mm, the heat capacity of the microreactor is reduced, and a microreactor with high energy use efficiency is provided. Can do.

  As shown in FIG. 3A, each side wall of the frame 723 and the partition wall 724 are erected by overlapping the bottom plate 722 on the frame 723 so that one opening of the frame 723 is covered with the bottom plate 722. Then, it is brought into contact with one surface 722d of the bottom plate 722. Then, a main power source 707 is connected to the bottom plate 722 so that the bottom plate 722 becomes the workpiece 710 of FIG. Toward the surface 722e. Then, a plasma arc 711 is ejected from the welding torch 701. The discharge direction of the plasma arc 711 is set to be perpendicular to the other surface 722e of the bottom plate 722. The welding torch 701 is moved relative to the bottom plate 722, the frame body 723, and the partition wall 724 so that the plasma arc 711 at the tip of the welding torch 701 traces the frame body 723 along the edge of the bottom plate 722. The portion traced to the other surface 722e of 722 is melted. The melted portion is then cooled and solidified in the atmosphere, and at this time, the frame body 723 is fixed and welded to the bottom plate 722 with each side wall of the frame body 723 standing. At this time, a part of the frame 723 that is in contact with the bottom plate 722 may be partially melted. It should be noted that a wax material may be interposed at the welded portion between the bottom plate 722 and the frame body 723. In this case, the wax material dissolves more quickly when the melting point is lower than that of the bottom plate 722 and the frame body 723. 722 and the frame 723 do not need to be heated excessively, and distortion of the bottom plate 722 and the like can be suppressed. In the case of using a wax material, the bottom plate 722 and the frame body 723 are not necessarily melted.

  Next, as shown in FIG. 3B, a plate-like jig 730 is placed on the bottom plate 722. The jig 730 is preferably formed of a material such as ceramic that has a melting point higher than the melting point of the bottom plate 722 and the molten bottom plate 722 is difficult to stick. Here, a notch 731 corresponding to the partition wall 724 is formed in the jig 730. When the jig 730 is overlapped with the bottom plate 722, the back surface of a predetermined portion of the one surface 722d of the bottom plate 722 exposed by the notch 731 of the jig 730. A partition wall 724 overlaps the side. Then, in a state where the plasma arc 711 is jetted from the welding torch 701 to the other surface of the bottom plate 722, the bottom plate 722, the frame body 723, and the frame 723 are traced along the cut 731 by the plasma arc 711 at the tip of the welding torch 701. The welding torch 701 is moved relative to the partition wall 724. The discharge direction of the plasma arc 711 is set to be perpendicular to the other surface 722e of the bottom plate 722. As a result, the partition wall 724 is welded to the bottom plate 722 while standing on the bottom plate 722. At this time, a part of the partition wall 724 that is in contact with the bottom plate 722 may be partially melted. By using such a jig 730, the welding location can be identified by the notch 731 and the heat around the welding location heated by the plasma arc 711 is transferred to the jig 730 in contact with the bottom plate 722 and diffused. It is possible to suppress the melting of the portion in contact with the jig 730 of 722 and locally heat the welded portion. Distortion of the bottom plate 722 and the like can be suppressed by locally heating the welding location. It should be noted that a wax material may be interposed at the welded portion between the bottom plate 722 and the partition wall 724. In this case, the wax material dissolves more quickly when the melting point is lower than that of the bottom plate 722 and the partition wall 724. The partition 724 does not need to be heated excessively, and distortion of the bottom plate 722 and the like can be suppressed. In the case of using a wax material, the bottom plate 722 and the partition 724 are not necessarily melted.

Next, as shown in FIG. 3C, the top plate 721 is overlaid on the frame body 723 so that the other opening of the frame body 723 is covered with the top plate 721. Each side wall 723 and the partition wall 724 are in a standing state, and are brought into contact with one surface 721d of the top plate 721. The welding torch 701 emits the plasma arc 711 toward the outer surface 721e of the top plate 721 in the same manner as the bottom plate 722 is joined to the frame body 723. The top plate 721 is heated to the surface 721d opposite to the surface 721e by the plasma arc 711, and the contact portion between the frame body 723 and the top plate 721 is melted, whereby the frame body 723 is formed at the edge of the top plate 721. Weld to. At this time, the discharge direction of the plasma arc 711 is set to be perpendicular to the outer surface 721e of the top plate 721. Further, a part of the frame 723 that is in contact with the top plate 721 may be partially melted. It should be noted that a wax material may be interposed at the welding location between the top plate 721 and the frame body 723. In this case, the wax material dissolves more quickly when the melting point is lower than that of the top plate 721 and the frame body 723. Therefore, it is not necessary to heat the top plate 721 and the frame body 723 excessively, and distortion of the top plate 721 and the like can be suppressed. When using a wax material, it is not always necessary to melt the top plate 721 and the frame body 723.
As described above, since the plasma arc 711 is emitted to the surface 721e opposite to the joining surface 721d, it is possible to apply heat to the abutting portion evenly compared to the conventional case where heating is performed obliquely as shown in FIG. And can be joined well.
Further, after the jig 730 is further disposed, the welding torch 701 emits the plasma arc 711 toward the outer surface 721e of the top plate 721, whereby the partition wall 724 is formed on the surface 721d opposite to the surface 721e from which the plasma arc 711 is emitted. Is welded to the top plate 721 (FIG. 3D). At this time, the discharge direction of the plasma arc 711 is set to be perpendicular to the outer surface 721e of the top plate 721. Further, a part of the partition wall 724 that is in contact with the top plate 721 may be partially melted. It should be noted that a wax material may be interposed at the welded portion between the top plate 721 and the partition wall 724. In this case, the wax material dissolves more quickly when the melting point is lower than that of the top plate 721 and the partition wall 724. The plate 721 and the partition 724 do not need to be heated excessively, and distortion of the top plate 721 and the like can be suppressed. In the case of using a wax material, the top plate 721 and the partition 724 are not necessarily melted.
As described above, since the plasma arc 711 is emitted to the surface 721e opposite to the joining surface 721d, it is possible to apply heat to the abutting portion evenly compared to the conventional case where heating is performed obliquely as shown in FIG. And can be joined well. In particular, as in the case of a microreactor, even when the interval between the partition walls 724 and the interval between the frame body 723 and the partition wall 724 are narrow, they can be easily joined.

  Before or after welding the top plate 721 and the bottom plate 722 as described above, the entire inner surface (the inner surface 721d of the top plate 721, the inner surface 722d of the bottom plate 722, the inner surface 723a of the frame body 723, and both sides of the partition wall 724). The catalyst is supported on the surface 724 a), and heating wires are patterned on the outer surfaces of the top plate 721, the bottom plate 722, and the frame body 723. When the catalyst is supported, a porous carrier such as aluminum oxide is previously formed on the entire inner surface of the channel 725, and then the carrier is allowed to catalyze.

  In the completed microreactor, the reactant reacts when the reactant is sent to the flow channel 725 and flows through the flow channel 725. The “reaction” here includes not only “chemical reaction” but also “state change” such as vaporization and liquefaction by receiving thermal energy. When a microreactor is used when changing the state of the reactant, it is better not to support the catalyst in the flow path 725.

  As shown in FIG. 4, before welding, a notch 722a along the partition 724 is formed in the bottom plate 722 by wire discharge or the like, and when the bottom plate 722 is welded as shown in FIG. 722a is overlapped, and the periphery of the bottom plate 722 is overlapped with the frame body 723, and the welding torch 701 emits the plasma arc 711 toward the outer surface 722e of the bottom plate 722. The bottom plate 722, the frame body 723, and the partition wall 724 are heated by direct contact with the plasma arc 711, and the contact portion between the frame body 723 and the bottom plate 722 and the contact portion between the partition wall 724 and the bottom plate 722 are melted. The frame 723 is welded to the edge of the bottom plate 722, and the partition 724 is welded to the periphery of the notch 722 a of the bottom plate 722. It should be noted that a wax material may be interposed at the welding point between the bottom plate 722 and the frame body 723 and the welding point between the bottom plate 722 and the partition wall 724, and in that case, the wax material is the bottom plate 722, the frame body 723, and the partition wall 724. If the melting point is lower than the melting point, the base plate 722, the frame body 723, and the partition wall 724 need not be heated excessively, and the distortion of the bottom plate 722, the frame body 723, and the partition wall 724 can be suppressed. In the case of using a wax material, it is not always necessary to melt the bottom plate 722, the frame 723, and the partition 724. The welding torch 701 may be moved relative to the bottom plate 722, the frame body 723, and the partition wall 724 so that the plasma arc 711 at the tip of the welding torch 701 traces the notch 722a along the notch 722a. The discharge direction of the plasma arc 711 is set in a direction perpendicular to the bottom plate 722.

  Similarly, a notch 721a along the partition wall 724 is formed on the top plate 721 before welding, and when the top plate 721 is welded, the notch 721a is overlaid on the partition wall 724, and the periphery of the top plate 721 is overlaid on the frame body 723. At the same time, the welding torch 701 emits a plasma arc 711 toward the outer surface 721e of the top plate 721. The top plate 721, the frame body 723, and the partition wall 724 are heated by direct contact with the plasma arc 711, and the contact portion between the frame body 723 and the top plate 721 and the contact portion between the partition wall 724 and the top plate 721 are melted. As a result, the frame 723 is welded to the edge of the top plate 721, and the partition 724 is welded to the periphery of the notch 721 a of the top plate 721. It should be noted that a wax material may be interposed at the welding location between the top plate 721 and the frame body 723 and the welding location between the top plate 721 and the partition wall 724, and in that case, the wax material is the top plate 721 and the frame body 723. Since the melting point is lower than that of the partition wall 724, the top plate 721, the frame body 723, and the partition wall 724 do not need to be heated excessively, and distortion of the top plate 721, the frame body 723, and the partition wall 724 can be suppressed. . In the case of using a wax material, the top plate 721, the frame body 723, and the partition wall 724 are not necessarily melted. The welding torch 701 may be moved relative to the top plate 721, the bottom plate 722, the frame body 723, and the partition 724 so that the plasma arc 711 at the tip of the welding torch 701 traces the cut 721a along the cut 721a. . The discharge direction of the plasma arc 711 is set to be perpendicular to the top plate 721. Here, since the top plate 721 and the bottom plate 722 are in contact with the partition wall 724, the widths of the cuts 721a and 722a are preferably smaller than the thickness of the partition wall 724.

  As described above, by forming the notches 721a and 722a in the top plate 721 and the bottom plate 722, energy required for welding can be suppressed, and distortion of the top plate 721 and the bottom plate 722 can be suppressed.

  Further, as shown in FIG. 6, before welding, a groove 722b along the frame body 723 and the partition wall 724 is formed on the outer surface 722e opposite to the joint surface of the bottom plate 722 by cutting or etching. A groove 721b along the frame body 723 and the partition wall 724 is formed on the outer surface 721e, which is the opposite surface of the joining surface of the top plate 721. As shown in FIG. 7, when welding the bottom plate 722, the frame 723 and the partition wall 724 are overlapped with the groove 722b, and the welding torch 701 faces the groove 722b of the outer surface 722e of the bottom plate 722 toward the plasma arc 711. Release. The bottom plate 722, the frame body 723, and the partition wall 724 are heated by the plasma arc 711, and the contact portion between the frame body 723 and the bottom plate 722 and the contact portion between the partition wall 724 and the bottom plate 722 are melted. And welded to the partition wall 724 to the inner surface 722d facing the groove 722b of the bottom plate 722. It should be noted that a wax material may be interposed at the welding point between the bottom plate 722 and the frame body 723 and the welding point between the bottom plate 722 and the partition wall 724, and in that case, the wax material is the bottom plate 722, the frame body 723, and the partition wall 724. If the melting point is lower than the melting point, the base plate 722, the frame body 723, and the partition wall 724 need not be heated excessively, and the distortion of the bottom plate 722, the frame body 723, and the partition wall 724 can be suppressed. In the case of using a wax material, it is not always necessary to melt the bottom plate 722, the frame 723, and the partition 724. The welding torch 701 may be moved relative to the bottom plate 722, the frame body 723, and the partition wall 724 so that the plasma arc 711 at the tip of the welding torch 701 traces the groove 722b along the groove 722b. The discharge direction of the plasma arc 711 is set in a direction perpendicular to the bottom plate 722.

  Similarly, when welding the top plate 721, the groove 721 b is superimposed on the frame body 723 and the partition wall 724, and the welding torch 701 emits the plasma arc 711 toward the groove 721 b on the outer surface 721 e of the top plate 721. . The top plate 721, the frame body 723, and the partition wall 724 are heated by the plasma arc 711, and the contact portion between the frame body 723 and the top plate 721 and the contact portion between the partition wall 724 and the top plate 721 are melted. The frame 723 is welded to the edge of the plate 721, and the partition 724 is welded to the inner surface 721 d facing the groove 721 b of the top plate 721. It should be noted that a wax material may be interposed at the welding location between the top plate 721 and the frame body 723 and the welding location between the top plate 721 and the partition wall 724, and in that case, the wax material is the top plate 721 and the frame body 723. Since the melting point is lower than that of the partition wall 724, the top plate 721, the frame body 723, and the partition wall 724 do not need to be heated excessively, and distortion of the top plate 721, the frame body 723, and the partition wall 724 can be suppressed. . In the case of using a wax material, the top plate 721, the frame body 723, and the partition wall 724 are not necessarily melted. The welding torch 701 may be moved relative to the top plate 721, the bottom plate 722, the frame body 723, and the partition wall 724 so that the plasma arc 711 at the tip of the welding torch 701 traces the groove 721b along the groove 721b. . The discharge direction of the plasma arc 711 is set to be perpendicular to the top plate 721.

  As described above, the top plate 721 and the bottom plate 722 have a structure in which the grooves 721b and 722b are thin and heat is more easily propagated by the plasma arc 711, and energy required for welding can be suppressed and can be joined quickly. Since there is mechanical strength compared with the case where there is a cut, distortion of the top plate 721 and the bottom plate 722 can be suppressed.

  Further, as shown in FIG. 8, before welding, a groove 722c along the frame body 723 and the partition wall 724 is formed on the joint surface 722d of the bottom plate 722, and a groove 721c along the frame body 723 and the partition wall 724 is formed on the top plate 721. It is formed on the joint surface 721d. The width of the groove 722c is set to be equal to or slightly wider than the width of the partition wall 724 and the frame body 723. When the bottom plate 722 is welded as shown in FIG. 9, the frame body 723 and the partition wall 724 are fitted into the groove 722c. Thus, the welding torch 701 emits the plasma arc 711 toward the surface 722e located on the opposite side of the groove 722c of the bottom plate 722. The bottom plate 722, the frame body 723, and the partition wall 724 are heated by the plasma arc 711, and the contact portion between the frame body 723 and the bottom plate 722 and the contact portion between the partition wall 724 and the bottom plate 722 are melted. And welded to the partition wall 724 through the groove 722 c of the bottom plate 722. It should be noted that a wax material may be interposed at the welding point between the bottom plate 722 and the frame body 723 and the welding point between the bottom plate 722 and the partition wall 724, and in that case, the wax material is the bottom plate 722, the frame body 723, and the partition wall 724. If the melting point is lower than the melting point, the base plate 722, the frame body 723, and the partition wall 724 need not be heated excessively, and the distortion of the bottom plate 722, the frame body 723, and the partition wall 724 can be suppressed. In the case of using a wax material, it is not always necessary to melt the bottom plate 722, the frame 723, and the partition 724. The welding torch 701 may be moved relative to the bottom plate 722, the frame body 723, and the partition wall 724 so that the plasma arc 711 at the tip of the welding torch 701 traces the groove 722c along the groove 722c.

  The width of the groove 721c is set to be equal to or slightly wider than the width of the partition wall 724 and the frame body 723. When the top plate 721 is welded, the groove 721c is fitted into the groove 721c and the welding torch 701. Emits a plasma arc 711 toward a surface 721e located on the opposite side of the groove 721c of the top plate 721. The top plate 721, the frame body 723, and the partition wall 724 are heated by the plasma arc 711, and the contact portion between the frame body 723 and the top plate 721 and the contact portion between the partition wall 724 and the top plate 721 are melted. The frame 723 is welded to the edge of the plate 721, and is welded to the partition wall 724 through the groove 721 c of the top plate 721. It should be noted that a wax material may be interposed at the welding location between the top plate 721 and the frame body 723 and the welding location between the top plate 721 and the partition wall 724, and in that case, the wax material is the top plate 721 and the frame body 723. Since the melting point is lower than that of the partition wall 724, the top plate 721, the frame body 723, and the partition wall 724 do not need to be heated excessively, and distortion of the top plate 721, the frame body 723, and the partition wall 724 can be suppressed. . In the case of using a wax material, the top plate 721, the frame body 723, and the partition wall 724 are not necessarily melted.

  The welding torch 701 may be moved relative to the top plate 721, the bottom plate 722, the frame body 723, and the partition wall 724 so that the plasma arc 711 at the tip of the welding torch 701 traces the groove 721c along the groove 721c. .

  As described above, by forming the grooves 721c and 722c in the top plate 721 and the bottom plate 722, welding is performed in a state where the frame body 723 and the partition 724 are fitted in the grooves 722c of the top plate 721 and the bottom plate 722 and temporarily fixed. Can be prevented from being displaced. Furthermore, energy required for welding can be suppressed, and distortion of the top plate 721 and the bottom plate 722 can be suppressed.

  Further, as shown in FIG. 10, before welding, a groove 722b is formed along the frame body 723 and the partition wall 724 on the opposite surface 722e of the joining surface 722d of the bottom plate 722, and the groove 722b of the joining surface 722d of the bottom plate 722 is formed. A groove 722c along the frame body 723 and the partition wall 724 is formed so as to face the position, and a groove 721b along the frame body 723 and the partition wall 724 is formed on the surface 721e opposite to the joint surface 721d of the top plate 721, A groove 721c along the frame body 723 and the partition 724 may be formed on the joint surface 721d of the top plate 721 so as to face the position of the groove 721b. The width of the groove 722c and the width of the groove 721c are set to be equal to or slightly wider than the widths of the partition wall 724 and the frame body 723. The width of the groove 722b and the groove 721b may be narrower than the thickness of the partition wall 724 and the frame body 723. 11, when the bottom plate 722 is welded, the frame body 723 and the partition wall 724 are fitted into the groove 722c, and the welding torch 701 faces the groove 722b located on the opposite side of the groove 722c of the bottom plate 722. A plasma arc 711 is emitted. The bottom plate 722, the frame body 723, and the partition wall 724 are heated by the plasma arc 711, and the contact portion between the frame body 723 and the bottom plate 722 and the contact portion between the partition wall 724 and the bottom plate 722 are melted. And welded to the partition wall 724 through the groove 722 c of the bottom plate 722. It should be noted that a wax material may be interposed at the welding point between the bottom plate 722 and the frame body 723 and the welding point between the bottom plate 722 and the partition wall 724, and in that case, the wax material is the bottom plate 722, the frame body 723, and the partition wall 724. If the melting point is lower than the melting point, the base plate 722, the frame body 723, and the partition wall 724 need not be heated excessively, and the distortion of the bottom plate 722, the frame body 723, and the partition wall 724 can be suppressed. In the case of using a wax material, it is not always necessary to melt the bottom plate 722, the frame 723, and the partition 724. The welding torch 701 is moved relative to the bottom plate 722, the frame body 723, and the partition wall 724 so that the plasma arc 711 at the tip of the welding torch 701 traces the groove 722b along the groove 722b.

  When the top plate 721 is welded, the groove 722c is fitted into the frame body 723 and the partition wall 724, and the welding torch 701 directs the plasma arc 711 toward the groove 721b located on the opposite side of the groove 721c of the top plate 721. discharge. The top plate 721, the frame body 723, and the partition wall 724 are heated by the plasma arc 711, and the contact portion between the frame body 723 and the top plate 721 and the contact portion between the partition wall 724 and the top plate 721 are melted. The frame 723 is welded to the edge of the plate 721, and is welded to the partition wall 724 through the groove 721 c of the top plate 721. It should be noted that a wax material may be interposed at the welding location between the top plate 721 and the frame body 723 and the welding location between the top plate 721 and the partition wall 724, and in that case, the wax material is the top plate 721 and the frame body 723. Since the melting point is lower than that of the partition wall 724, the top plate 721, the frame body 723, and the partition wall 724 do not need to be heated excessively, and distortion of the top plate 721, the frame body 723, and the partition wall 724 can be suppressed. . In the case of using a wax material, the top plate 721, the frame body 723, and the partition wall 724 are not necessarily melted. The welding torch 701 is moved relative to the top plate 721, the bottom plate 722, the frame body 723, and the partition wall 724 so that the plasma arc 711 at the tip of the welding torch 701 traces the groove 721b along the groove 721b.

  As described above, by forming the grooves 721b and 722b and the grooves 721c and 722c in the top plate 721 and the bottom plate 722, energy required for welding can be suppressed, and distortion of the top plate 721 and the bottom plate 722 can be suppressed.

  In the above description, the frame body 723 and the partition wall 724 are formed by die-sinking electric discharge machining, but the frame body 723 and the partition wall 724 may be assembled by a microplasma welding method using a welding torch 701. That is, when assembling four thin plates into a rectangular frame shape, each corner is welded by a microplasma arc welding method to create a frame body 723, and further, on the inner surface of two side walls of the four side walls of the frame body 723 The partition wall 724 is welded by a microplasma arc welding method.

[Application example]
The above-described microplasma arc welding method can be used in the method of manufacturing the microreactor module 1 shown in FIGS.

  Here, the microreactor module 1 will be briefly described. The microreactor module 1 includes a base plate 102, a lower frame 104, a middle frame 106, a combustor plate 108, an upper frame 110, a lid plate 112, a high temperature reaction unit 4, a base plate 28, a lower frame 30, and a middle frame 32. The low temperature reaction part 6 in which the upper frame 34 and the lid plate 36 are laminated, the connecting pipe 8 laid between the high temperature reaction part 4 and the low temperature reaction part 6, and the multi-tube 10 connected to the lower surface of the low temperature reaction part 6. And a combustor plate 12 stacked around the multi-tubular material 10, a heating wire 170 patterned on the lower surface of the low temperature reaction unit 6, and a patterning on the lower surface from the low temperature reaction unit 6 to the connecting pipe 8 and the high temperature reaction unit 4. And a heating wire 174 patterned from the lower surface of the low-temperature reaction section 6 to the outer surface of the combustor plate 12.

  Although the combustor plate 12 is joined and a flow path is formed on the joint surface, a mixture of gaseous fuel and air flows into the flow path of the combustor plate 12 through the multi-tubular material 10, and catalytic combustion occurs in the flow path. Happens. In addition, a liquid mixture of liquid fuel and water is supplied to the multi-pipe material 10, but the liquid mixture is vaporized by the combustion heat in the combustor plate 12 and the heating wire 174. The vaporized fuel / water mixture is sent to the inside of the lower part of the high temperature reaction section 4 through the flow path of the base plate 28 and the connecting pipe 8. The lower part of the high-temperature reaction unit 4 is a stack of the base plate 102, the lower frame 104, and the middle frame 106. A flow path is formed inside these stacked bodies, and an air-fuel mixture flows through the flow path to generate hydrogen or the like. Produced by catalytic reaction. Although heat is required for this catalytic reaction, heat energy is supplied from the heating wire 172 or the combustor plate 108. Here, when the combustor plate 108 is joined to the upper frame 110, a combustion chamber is formed on the joining surface, and a mixture of gaseous fuel and air passes through the multi-tube member 10, the flow path of the base plate 28, and the connecting pipe 8. Supplyed to the combustion chamber, catalytic combustion occurs in the combustion chamber.

  The air-fuel mixture is further sent to the inside of the upper frame 110 from the laminated body of the base plate 102, the lower frame 104, and the middle frame 106. A plurality of partition walls 109 are provided inside the upper frame 110, and a flow path is formed inside the upper frame 110 by closing the upper opening of the upper frame 110 by the lid plate 112. The air-fuel mixture sent to the inside of the upper frame 110 flows through the flow path inside the upper frame 110, and hydrogen and the like are generated by a catalytic reaction. Then, an air-fuel mixture containing hydrogen or the like is sent to the inside of the low temperature reaction part 6 through the connecting pipe 8.

  The low-temperature reaction unit 6 is formed by laminating a base plate 28, a lower frame 30, a middle frame 32, an upper frame 34, and a lid plate 36. A flow path is formed inside these laminated bodies, and the flow path is mixed with the mixed gas. Flows to selectively oxidize carbon monoxide in the air-fuel mixture. Since the selective oxidation reaction of carbon monoxide occurs at a temperature higher than room temperature, the low temperature reaction part 6 is heated by the heating wire 170 or the combustor plate 12. Hydrogen-rich gas from which carbon monoxide has been removed in the low-temperature reaction section 6 is supplied to the fuel electrode of the fuel cell through the multi-tube material 10. In a fuel cell, air is supplied to an oxygen electrode, and electric energy is generated by an electrochemical reaction between oxygen and hydrogen.

  Although the high temperature reaction part 4, the low temperature reaction part 6, and the connection pipe 8 are accommodated in the heat insulation package, since the inside of the heat insulation package is made into the vacuum pressure, the heat insulation effect is high. Further, a getter material 188 is provided in the heat insulation package, and when a voltage is applied to the heater of the getter material 188 through the lead wires 192 and 194 and the wiring 190, the getter material 188 is activated and the degree of vacuum in the heat insulation package is increased. . In addition to the lead wires 192 and 194, several lead wires are provided. The lead wires 176 and 178 are connected to the heating wire 170, the lead wires 180 and 182 are connected to the heating wire 172, and the lead wire 184 is connected. , 186 are connected to the heating wire 174.

  In order to manufacture the microreactor module 1, the above-described microplasma arc welding method is used. In particular, when the lid plate 112 is joined to the upper frame 110 or when the lid plate 36 is joined to the upper frame 34, the above-mentioned microplasma is used. Use arc welding method.

  Here, the lid plates 36 and 112 correspond to the top plate 721 or the bottom plate 722 described above, the upper frames 34 and 110 correspond to the frame body 723 described above, and the partition walls 33 and 109 correspond to the partition walls 724. That is, the opening of the upper frame 34 is covered with the lid plate 36, and the upper frame 34 and the partition wall 33 are traced by the plasma arc 711 at the tip of the welding torch 701 from above the lid plate 36, thereby joining the lid plate 36 to the upper frame 34. The opening of the upper frame 110 is covered with the lid plate 112, and the upper frame 110 and the partition wall 109 are traced from above the lid plate 112 with the plasma arc 711 at the tip of the welding torch 701, so that the lid plate 112 is 110 can be joined.

It is the schematic of a welding apparatus. It is a disassembled perspective view of a microreactor. FIG. 3 is a cross-sectional view sequentially illustrating manufacturing steps of the microreactor of FIG. 2. It is a disassembled perspective view of a microreactor. It is sectional drawing which showed the manufacturing method of the microreactor of FIG. It is a disassembled perspective view of a microreactor. It is sectional drawing which showed the manufacturing method of the microreactor of FIG. It is a disassembled perspective view of a microreactor. It is sectional drawing which showed the manufacturing method of the microreactor of FIG. It is a disassembled perspective view of a microreactor. It is sectional drawing which showed the manufacturing method of the microreactor of FIG. It is a perspective view of the micro reactor module shown from diagonally below. It is a disassembled perspective view of a micro reactor module. It is the figure which showed the conventional welding method.

Explanation of symbols

1 Microreactor module 33, 109 Bulkhead 34, 110 Upper frame 36, 112 Lid plate 701 Welding torch 711 Plasma arc 721 Top plate 722 Bottom plate 723 Frame body 724 Bulkhead 721a, 722a Cut 721b, 722b Groove 721c, 722c Groove

Claims (11)

  The plate-like second workpiece is brought into contact with one surface of the plate-like first workpiece, and the first workpiece is opposite to the one surface of the first workpiece. A plasma arc welding method, wherein welding is performed in a state where the second workpiece is raised on the first workpiece by ejecting a plasma arc.   A notch is formed in the first workpiece so that the second workpiece is in contact with the first workpiece, and the plasma arc is ejected toward the notch. The plasma arc welding method according to claim 1.   A groove is formed on the opposite surface of the first workpiece so that the second workpiece is in contact with the first surface where the second workpiece contacts the first workpiece. The plasma arc welding method according to claim 1, wherein the plasma arc is ejected.   A groove is formed on the one surface of the first workpiece so that the second workpiece is in contact with the first workpiece, and the groove of the first workpiece is 4. The plasma arc welding method according to claim 1, wherein the plasma arc is ejected toward a position corresponding to the groove on the opposite surface. 5.   The plasma arc welding method according to claim 4, wherein the plasma arc is ejected in a state where the second workpiece is fitted in the groove.   A microreactor manufacturing method, characterized in that a microreactor is manufactured using the plasma arc welding method according to any one of claims 1 to 5. A step of stacking the plate on the frame so as to cover the opening of the frame provided with a partition wall on the inner surface with the plate;
And a step of welding the frame and the partition to the plate by ejecting a plasma arc to the plate from the opposite side of the frame and the partition with respect to the plate.   The notch is formed in the plate material so that the partition wall is in contact with the plate material, and the plasma arc is ejected toward the notch to weld the partition wall to the plate material. A method for producing the microreactor as described.   A groove is formed on the surface of the plate opposite to the frame so that the frame and the partition come into contact with the plate, and the plasma arc is ejected toward the groove to eject the plasma arc. The method for manufacturing a microreactor according to claim 7, wherein the partition wall is welded to the plate member.   A groove is formed on the surface of the plate material on the side opposite to the frame so that the frame body and the partition wall are in contact with the plate material, and corresponds to the groove on the surface of the plate material opposite to the frame body. 10. The method of manufacturing a microreactor according to claim 7, wherein the frame body and the partition wall are welded to the plate member by ejecting the plasma arc toward a place.   The method of manufacturing a microreactor according to claim 10, wherein the plasma arc is ejected in a state where the frame body and the partition wall are fitted in the groove.

Images