Patent Publication Number: US-2006019144-A1

Title: Channel-incorporating pedestal and method for producing same

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      This invention relates to a channel-incorporating pedestal, and a method for producing it.  
      2. Description of the Related Art  
      A channel-incorporating pedestal is applied, for example, to various systems in various industrial fields, such as a stationary fuel cell power generation system for domestic use or a movable fuel cell power generation system for installation in a vehicle, and fluid control systems, e.g., air brake systems for trains. That is, the channel-incorporating pedestal is configured such that various instruments, such as components and devices constituting these systems, are mounted on the surface of the pedestal, built-in channels (grooves) are provided in place of complicated piping connecting these instruments (the built-in channels function as the piping), and further electrical wiring is also incorporated. The channel-incorporating pedestal, so configured, is put to practical uses as compact integrated units, such as stationary units including domestic fuel cell power generation units, and moving units including vehicle-installed fuel cell power generation units.  
      Various proposals have been made for concrete configurational examples of the channel-incorporating pedestal. For example, those disclosed in Japanese Patent Application Laid-Open No. 2002-305010 can be named. A configurational example of a conventional channel-incorporating pedestal will be described hereinbelow with reference to FIGS.  6  to  8 .  FIG. 6  is a sectional view showing the configuration of the conventional channel-incorporating pedestal (a sectional view taken on line A-A of  FIG. 7 ),  FIG. 7  is a plan view taken in the direction of B in  FIG. 6 , and  FIG. 8  is a sectional view taken on line C-C of  FIG. 6 .  
      As shown in  FIGS. 6, 7  and  8 , a channel-incorporating pedestal  1  comprises an upper plate  2  and a lower plate  3  joined together by publicly known friction stir welding or a suitable binder  4 . Various instruments  5 , such as components and devices constituting, for example, a fuel cell power generation system or a fluid control system, which are suitably placed on the surface  2   a  of the upper plate  2 , are fixed by clamping, integrally with the upper and lower plates  2  and  3 , by bolts  6  inserted through bolt holes  2   b  and  3   a  formed in the upper and lower plates  2  and  3 , and nuts  7  screwed to the bolts  6 . That is, the channel-incorporating pedestal  1  functions as a pedestal for mounting the instruments  5 .  
      A groove  8  is formed in a joining surface  3   b  of the lower plate  3 . Generally, a plurality of the grooves  8  are formed, have predetermined sectional areas, and are formed with suitable lengths in suitable directions. The upper plate  2  is joined to the lower plate  3  in such a manner as to cover the groove  8  (put a lid on the groove  8 ) formed in the lower plate  3 . As a result, a channel for a fluid, which consists of the groove  8 , is formed within the channel-incorporating pedestal  1 .  
      Communication holes  9  are formed in the upper plate  2 , and the groove  8  are brought into communication with the instruments  5  via these communication holes  9 . That is, the groove  8  is incorporated, as the channel for a fluid, in the channel-incorporating pedestal  1 . These built-in channels (grooves  8 ) have the function of piping connecting the instruments  5  together. In other words, the channel-incorporating pedestal  1  also functions as integrated piping. The sectional area of each groove  8  (built-in channel) is determined by the properties, flow velocity and pressure loss of a fluid flowing in each groove  8 , and the length and direction of each groove  8  (built-in channel) are determined, for example, by the arrangement of the instruments  5 .  
      As the material for the upper and lower plates  2  and  3 , an aluminum plate is used most frequently because of its light weight, strength, and ease of processing. Other materials in frequent use are a metallic material such as a steel plate, and a metallic material such as a casting product.  
      There may be a case where the fluid flowing through the groove  8  and the communication hole  9  is a corrosive fluid for the metallic material constituting the upper and lower plates  2  and  3 , or has a possibility for corroding the metallic material, for example, by a local cell action. In this case, the surfaces of the groove  8  and the communication hole  9 , which are in contact with the fluid, are coated with an aluminum oxide film (alumite), or are subjected to corrosion protection by polytetrafluoroethylene (PTFE: Teflon®) coating. Alternatively, the upper plate  2  and the lower plate  3 , as a whole, are produced, for example, from corrosion-free synthetic resin. Such measures have so far dealt with possible corrosion.  
      However, the measures for corrosion protection involve a complicated manufacturing process, require a long time for completion, and need a great investment in production facilities, thus entailing high costs. Moreover, the production of the upper and lower plates  2  and  3 , as a whole, from corrosion-free synthetic resin poses problems, such that some reinforcement is required, and the use of the synthetic resin is feasible only when the pressure of the fluid flowing through the groove  8  is low, because the upper and lower plates  2  and  3  generally undergo marked deformation, and their mechanical strength is low.  
      The present invention has been accomplished in light of the above-described circumstances. It is an object of the present invention to provide a channel-incorporating pedestal having corrosion resistance, which can be produced at a low cost, and which can ensure mechanical strength, and a method for producing the channel-incorporating pedestal.  
     SUMMARY OF THE INVENTION  
      An aspect of the present invention is a channel-incorporating pedestal  
      comprising a first plate and a second plate joined together,  
      incorporating a groove, which is formed on a joining surface of the first plate, as a channel for a fluid, and  
      bringing the groove into communication with an instrument, which is placed on a surface of the first plate, via a communication hole formed in the first plate, and  
      wherein the first plate comprises an anticorrosive material,  
      the second plate comprises a metallic material, and  
      the fist plate and the second plate are bonded together by an adhesive protective sheet interposed between the first plate and the second plate, the adhesive protective sheet having a lower melting point than melting points of the first plate and the second plate, and being thermoplastic and anticorrosive.  
      Another aspect of the present invention is a channel-incorporating pedestal  
      comprising a first plate, a second plate, and a third plate joined together, with the second plate being interposed between the first plate and the third plate,  
      incorporating a first groove, which is formed on a joining surface of the first plate, and a second groove, which is formed on a joining surface of the third plate, as channels for fluids,  
      bringing the first groove into communication with an instrument, which is placed on a surface of the first plate, via a first communication hole formed in the first plate, and  
      bringing the second groove into communication with an instrument, which is placed on a surface of the third plate, via a second communication hole formed in the third plate, and  
      wherein the first plate and the third plate comprise an anticorrosive material,  
      the second plate comprises a metallic material,  
      the fist plate and the second plate are bonded together by a first adhesive protective sheet interposed between the first plate and the second plate, the first adhesive protective sheet having a lower melting point than melting points of the first plate, the second plate, and the third plate, and being thermoplastic and anticorrosive, and  
      the third plate and the second plate are bonded together by a second adhesive protective sheet interposed between the third plate and the second plate, the second adhesive protective sheet having a lower melting point than melting points of the first plate, the second plate, and the third plate, and being thermoplastic and anticorrosive.  
      Still another aspect of the present invention is a method for producing a channel-incorporating pedestal,  
      the channel-incorporating pedestal  
      comprising a first plate and a second plate joined together,  
      incorporating a groove, which is formed on a joining surface of the first plate, as a channel for a fluid, and  
      bringing the groove into communication with an instrument, which is placed on a surface of the first plate, via a communication hole formed in the first plate,  
      the method comprising  
      using a plate comprising an anticorrosive material as the first plate,  
      using a plate comprising a metallic material as the second plate, and  
      pressurizing and heating the fist plate and the second plate, with an adhesive protective sheet being interposed between the first plate and the second plate, the adhesive protective sheet having a lower melting point than melting points of the first plate and the second plate, and being thermoplastic and anticorrosive, to melt the adhesive protective sheet, thereby bonding the first plate and the second plate together by the adhesive protective sheet.  
      A further aspect of the present invention is a method for producing a channel-incorporating pedestal, the channel-incorporating pedestal  
      comprising a first plate, a second plate, and a third plate joined together, with the second plate being interposed between the first plate and the third plate,  
      incorporating a first groove, which is formed on a joining surface of the first plate, and a second groove, which is formed on a joining surface of the third plate, as channels for fluids,  
      bringing the first groove into communication with an instrument, which is placed on a surface of the first plate, via a first communication hole formed in the first plate, and  
      bringing the second groove into communication with an instrument, which is placed on a surface of the third plate, via a second communication hole formed in the third plate,  
      the method comprising  
      using plates comprising an anticorrosive material as the first plate and the third plate, using a plate comprising a metallic material as the second plate,  
      pressurizing and heating the fist plate, the second plate, and the third plate, with a first adhesive protective sheet being interposed between the first plate and the second plate, the first adhesive protective sheet having a lower melting point than melting points of the first plate, the second plate, and the third plate, and being thermoplastic and anticorrosive, and with a second adhesive protective sheet being interposed between the third plate and the second plate, the second adhesive protective sheet having a lower melting point than melting points of the first plate, the second plate, and the third plate, and being thermoplastic and anticorrosive, to melt the first adhesive protective sheet and the second adhesive protective sheet, thereby bonding the first plate and the second plate together by the first adhesive protective sheet, and bonding the third plate and the second plate together by the second adhesive protective sheet. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:  
       FIG. 1  is a sectional view showing the configuration of a channel-incorporating pedestal according to Embodiment 1 of the present invention (a sectional view taken on line D-D of  FIG. 2 );  
       FIG. 2  is a plan view taken in the direction of E in  FIG. 1 ;  
       FIG. 3  is a sectional view taken on line F-F of  FIG. 1 ;  
       FIG. 4  is a sectional view showing the configuration of a channel-incorporating pedestal according to Embodiment 2 of the present invention;  
       FIG. 5  is a sectional view taken on line G-G of  FIG. 4 ;  
       FIG. 6  is a sectional view showing the configuration of a conventional channel-incorporating pedestal (a sectional view taken on line A-A of  FIG. 7 );  
       FIG. 7  is a plan view taken in the direction of B in  FIG. 6 ; and  
       FIG. 8  is a sectional view taken on line C-C of  FIG. 6 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Embodiment 1  
       FIG. 1  is a sectional view showing the configuration of a channel-incorporating pedestal according to Embodiment  1  of the present invention (a sectional view taken on line D-D of  FIG. 2 ),  FIG. 2  is a plan view taken in the direction of E in  FIG. 1 , and  FIG. 3  is a sectional view taken on line F-F of  FIG. 1 .  
      As shown in  FIGS. 1, 2  and  3 , a channel-incorporating pedestal  21  comprises an upper plate  22 , as a first plate, and a lower plate  23 , as a second plate, joined together. An adhesive protective sheet  25  is interposed between the upper plate  22  and the lower plate  23 . Various instruments  24 , such as components and devices constituting, for example, a fuel cell power generation system or a fluid control system, are placed on the surface  22   c  of the upper plate  22 . These instruments  24  are fixed by clamping, integrally with the upper and lower plates  22  and  23 , by bolts  26  inserted through bolt holes  22   a,    23   a  and  25   a  formed in the upper and lower plates  22  and  23  and the adhesive protective sheet  25 , and nuts  27  screwed to the bolts  26 . That is, the channel-incorporating pedestal  21  functions as a pedestal for mounting the instruments  24 .  
      A groove  28  is formed in a joining surface  22   b  of the upper plate  22  by suitable means such as machining, injection molding, or die casting. Generally, a plurality of the grooves  28  are formed, have predetermined sectional areas (widths and depths), and are formed with suitable lengths in suitable directions. The lower plate  23  is joined to the upper plate  22  via the adhesive protective sheet  25  in such a manner as to cover the groove  28  formed in the upper plate  22 . As a result, a channel for a fluid, which consists of the groove  28 , is formed within the channel-incorporating pedestal  21 .  
      Communication holes  29  are formed in the upper plate  22 , directly below the instruments  24  disposed on the upper plate  22 , by suitable means such as machining, injection molding, or die casting. The groove  28  is brought into communication with the instruments  24  via these communication holes  29 . That is, the groove  28  is incorporated, as the channel for a fluid, in the channel-incorporating pedestal  21 . These built-in channels (grooves  28 ) have the function of piping connecting the instruments  24  together. Thus, the channel-incorporating pedestal  21  also functions as integrated piping. The sectional area of each groove  28  (built-in channel) is determined by the properties, flow velocity and pressure loss of the fluid flowing in each groove  28 , and the length and direction of each groove  28  (built-in channel) are determined, for example, by the arrangement of the instruments  24 . A clearance between the communication hole  29  and the instrument  24  is sealed with an O ring  31 .  
      The upper plate  22  comprises a nonmetallic material having corrosion resistance, and the lower plate  23  comprises a metallic material. Examples of the corrosion-resistant material are corrosion-free synthetic resins, such as fluoroplastic plates, for example, polytetrafluoroethylene (PTFE: Teflon). As examples of the metallic material, an aluminum plate and a steel plate can be named. The thickness of the lower plate  23  is a suitable thickness for required mechanical strength.  
      The adhesive protective sheet  25  is a thermoplastic and corrosion-resistant one. A publicly known, commercially available product can be used as the adhesive protective sheet  25 . To be selected as the adhesive protective sheet  25  is a sheet-shaped product which is based on the same material as that of the upper plate  22 , which has a suitable thickness, and which comprises, for example, a thermoplastic synthetic resin well compatible with and highly adhesive to a joining surface  23   b  of the lower plate  23 . Furthermore, the adhesive protective sheet  25  has to have a lower melting point than those of the upper plate  22  and the lower plate  23 . For example, if the material for the lower plate  23  is aluminum, and the material for the upper plate  22  is PTFE, then a material having a lower melting point than the melting point of PTFE (327° C.) needs to be selected for the adhesive protective sheet  25 .  
      A method for producing the channel-incorporating pedestal  21  will be described. First, the adhesive protective sheet  25  is sandwiched (interposed) between the upper plate  22  and the lower plate  23  throughout the surfaces of the upper and lower plates  22  and  23 . Then, in this state, a suitable pressurizing means (pressing means) is applied to the upper and lower plates  22  and  23 , such that the upper and lower plates  22  and  23  are clamped by a clamping device (not shown), or a heavy object is placed on the upper and lower plates  22  and  23 . By this measure, the adhesive protective sheet  25 , together with the upper and lower plates  22  and  23 , is pressurized (given pressure) under a suitable pressurizing force. Moreover, the adhesive protective sheet  25 , together with the upper and lower plates  22  and  23 , is heated by a heating means, such as a baking furnace (heating furnace), to a suitable temperature at which the adhesive protective sheet  25  is melted and adhered. The pressurizing force and the heating temperature differ according to the type of the adhesive protective sheet  25 . For example, the heating temperature is usually several hundred degrees centigrade.  
      As a result, the upper plate  22  and the lower plate  23  are bonded together by the adhesive protective sheet  25 .  
      Concretely, at the portion of joining between the upper and lower plates  22  and  23 , namely, at a portion where the adhesive protective sheet  25  contacts the joining surface  22   b  of the upper plate  22  and the joining surface  23   b  of the lower plate  23  (i.e., the portion other than the portion corresponding to the groove  28  formed in the upper plate  22 ), the upper and lower plates  22  and  23  are bonded by the adhesive protective sheet  25 . In the non-joining portion of the upper and lower plates  22  and  23 , namely, the portion corresponding to the groove  28  formed in the upper plate  22 , the adhesive protective sheet  25  is fusion bonded to the joining surface  23   b  of the lower plate  23 , coating or lining the joining surface  23   b.  Thus, the adhesive protective sheet  25  protects the relevant portion of the lower plate  23  from a corrosive fluid flowing in the groove  28 .  
      Then, the instruments  24  are placed on the upper plate  22 , and they are clamped by the bolts  26  and the nuts  27  for fixing, whereby sufficient strength of the bonding surfaces can be ensured. Furthermore, if it is necessary to enhance the bond strength between the upper and lower plates  22  and  23  because the fluid flowing through the groove  28  is at a high pressure, the upper and lower plates  22  and  23  and the adhesive protective sheet  25  may be clamped together by the bolts  26  and the nuts  27  via a suitable metal plate  30  disposed on the upper plate  22  for the purpose of reinforcement. In this case, it is vital that the bolt holes  22   a,    23   a  and  25   a  evade the groove  28 .  
      The adhesive protective sheet  25  on the market will be illustrated. If, for example, the upper plate  22  is formed from PTFE, “RAP” (commercial name) of DAIKIN INDUSTRIES, which is an adhesive protective sheet comprising the same series of material as PTFE, was used, and bonded under pressure at a heating temperature of about 300° C. Satisfactory bond strength and anti-corrosion effect were obtained.  
      As described above, the channel-incorporating pedestal  21  of the present Embodiment 1 comprises the upper plate  22  and the lower plate  23  joined together, incorporates the groove  28 , which is formed on the joining surface  22   b  of the upper plate  22 , as the channel for the fluid, and brings the groove  28  into communication with the instruments  24 , which are placed on the surface  22   c  of the upper plate  22 , via the communication holes  29  formed in the upper plate  22 . This channel-incorporating pedestal is characterized in that the upper plate  22  comprises the anticorrosive material, the lower plate  23  comprises the metallic material, and the upper plate  22  and the lower plate  23  are bonded together by the adhesive protective sheet  25  interposed between the upper plate  22  and the lower plate  23 , the adhesive protective sheet  25  having a lower melting point than the melting points of the upper plate  22  and the lower plate  23 , and being thermoplastic and anticorrosive.  
      The method for producing the channel-incorporating pedestal  21  of the present Embodiment 1 is a method for producing a channel-incorporating pedestal, which comprises the upper plate  22  and the lower plate  23  joined together, incorporates the groove  28 , formed on the joining surface  22   b  of the upper plate  22 , as the channel for the fluid, and brings the groove  28  into communication with the instruments  24 , placed on the surface  22   c  of the upper plate  22 , via the communication holes  29  formed in the upper plate  22 . This method is characterized by using the anticorrosive material as the upper plate  22 , using the metallic material as the lower plate  23 , and pressurizing and heating the upper plate  22  and the lower plate  23 , with the adhesive protective sheet  25  being interposed between the upper plate  22  and the lower plate  23 , the adhesive protective sheet  25  having a lower melting point than the melting points of the upper plate  22  and the lower plate  23 , and being thermoplastic and anticorrosive, to melt the adhesive protective sheet  25 , thereby bonding the upper plate  22  and the lower plate  23  together by the adhesive protective sheet  25 .  
      According to the present Embodiment 1, as described above, the upper plate  22  having the groove  28  and the communication holes  29  formed therein comprises the anticorrosive material, and the lower plate  23  comprising the metallic material is protected by the anticorrosive adhesive protective sheet  25 . Thus, the upper plate  22  and the lower plate  23  have corrosion resistance, for example, to the corrosive fluid flowing in the groove  28 . Furthermore, the lower plate  23  comprises the metallic material, so that the lower plate  23  can ensure the mechanical strength of the channel-incorporating pedestal  21 . If further strength is needed, the further strength can be easily obtained simply by increasing the wall thickness of the lower plate  23 . Moreover, the strength can be easily enhanced by clamping the upper plate  22  and the lower plate  23  by the bolt  26  and the nut  27  via the metal plate  30 .  
      Besides, corrosion prevention can be easily performed simply by bonding the upper and lower plates  22  and  23  together by the adhesive protective sheet  25 . For example, the lower plate  23  has the simplest flat surface. Thus, merely by applying a suitable pressurizing force and a suitable heating temperature to the adhesive protective sheet  25 , satisfactory bonding force and anticorrosive performance can be ensured easily. Consequently, as compared with a conventional corrosion prevention measure such as aluminum oxide film coating, the channel-incorporating pedestal  21  with anticorrosive properties can be produced easily, and cost reduction can be achieved. If a synthetic resin such as PTFE is used as the material for the upper plate  22 , the groove  28  and the communication holes  29  can be formed easily by a method such as machining, injection molding, or die casting. Thus, further cost reduction can be achieved.  
     Embodiment 2  
       FIG. 4  is a sectional view showing the configuration of a channel-incorporating pedestal according to Embodiment 2 of the present invention.  FIG. 5  is a sectional view taken on line G-G of  FIG. 4 .  
      As shown in  FIGS. 4 and 5 , a channel-incorporating pedestal  41  comprises an upper plate  42  as a first plate, an upper plate  43  as a third plate, and a lower plate  44  as a second plate joined together, with the lower plate  44  being interposed between the upper plate  42  and the upper plate  43 . That is, the two upper plates  42  and  43  are stacked in opposed relation, with the lower plate  44  being interposed therebetween, to make up a multistage configuration. An adhesive protective sheet  45  is interposed between the upper plate  42  and the lower plate  44 , and an adhesive protective sheet  46  is interposed between the upper plate  43  and the lower plate  44 .  
      Various instruments  47 , such as components and devices constituting, for example, a fuel cell power generation system or a fluid control system, are placed on the surface  42   a  of the upper plate  42  and the surface  43   a  of the upper plate  43 . The instruments  47 , which are placed in vertical alignment, are fixed by clamping, integrally with the upper and lower plates  42 ,  43  and  44 , by bolts  48  inserted through bolt holes  42   b,    43   b,    44   a,    45   a,    46   a  formed in the upper and lower plates  42 ,  43  and  44  and the adhesive protective sheets  45  and  46 , and nuts  49  screwed to the bolts  48 . The instruments  47 , which are placed out of vertical alignment, are fixed by clamping, integrally with the upper and lower plates  42 ,  44  or the upper and lower plates  43 ,  44 , by stud bolts  50  driven into the lower plate  44  and inserted through the bolt holes  45   a,    42   b  or the bolt holes  46   a,    43   b,  and nuts  51  screwed to the stud bolts  50 . That is, the channel-incorporating pedestal  41  functions as a pedestal for mounting the instruments  47 .  
      Grooves  52  are formed in a joining surface  42   c  of the upper plate  42  and a joining surface  43   c  of the upper plate  43  by suitable means such as machining, injection molding, or die casting. Generally, a plurality of the grooves  52  are formed, have predetermined sectional areas (widths and depths), and are formed with suitable lengths in suitable directions. The lower plate  44  is joined to the upper plate  42  and the upper plate  43  via the adhesive protective sheets  45 ,  46  in such a manner as to cover the groove  52 , as a first groove, formed in the upper plate  42 , and the groove  52 , as a second groove, formed in the upper plate  43 . As a result, channels for fluids, which consist of the grooves  52 , are formed within the channel-incorporating pedestal  41 .  
      Communication holes  53  are formed in the upper plates  42 ,  43 , directly below the instruments  47  disposed on the upper plates  42 ,  43 , by suitable means such as machining, injection molding, or die casting. The groove  52  of the upper plate  42  is brought into communication with the instruments  47  on the upper plate  42  via the communication holes  53  of the upper plate  42 . The groove  52  of the upper plate  43  is brought into communication with the instruments  47  on the upper plate  43  via the communication holes  53  of the upper plate  43 . That is, the grooves  52  are incorporated, as the channels for fluids, in the channel-incorporating pedestal  41 . These built-in channels (grooves  52 ) have the function of piping connecting the instruments  47  together. Thus, the channel-incorporating pedestal  41  also functions as integrated piping. The sectional area of each groove  52  (built-in channel) is determined by the properties, flow velocity and pressure loss of the fluid flowing in each groove  52 , and the length and direction of each groove  52  (built-in channel) are determined, for example, by the arrangement of the instruments  47 . A clearance between the communication hole  53  and the instrument  47  is sealed with an O ring  55 .  
      The upper plates  42 ,  43  each comprise a nonmetallic material having corrosion resistance, and the lower plate  44  comprises a metallic material. Examples of the corrosion-resistant material are corrosion-free synthetic resins, such as fluoroplastic plates, for example, polytetrafluoroethylene (PTFE: Teflon). As examples of the metallic material, an aluminum plate and a steel plate can be named. The thickness of the lower plate  44  is a suitable thickness for required mechanical strength.  
      The adhesive protective sheets  45 ,  46  are thermoplastic and corrosion-resistant ones. A publicly known, commercially available product can be used as the adhesive protective sheets  45 ,  46 . To be selected as the adhesive protective sheets  45 ,  46  is a sheet-shaped product which is based on the same material as that of the upper plates  42 ,  43 , which has a suitable thickness, and which comprises, for example, a thermoplastic synthetic resin well compatible with and highly adhesive to the joining surfaces  44   b,    44   c  of the lower plate  44 . Furthermore, the adhesive protective sheets  45 ,  46  have to have a lower melting point than those of the upper plates  42 ,  43  and the lower plate  44 . For example, if the material for the lower plate  44  is aluminum, and the material for the upper plates  42 ,  43  is PTFE, then a material having a lower melting point than the melting point of PTFE (327° C.) needs to be selected for the adhesive protective sheets  45 ,  46 .  
      A method for producing the channel-incorporating pedestal  41  will be described. First, the adhesive protective sheet  45  is sandwiched (interposed) between the upper plate  42  and the lower plate  44  throughout the surfaces of the upper and lower plates  42  and  44 . Also, the adhesive protective sheet  46  is sandwiched (interposed) between the upper plate  43  and the lower plate  44  throughout the surfaces of the upper and lower plates  43  and  44 . Then, in this state, a suitable pressurizing means (pressing means) is applied to the upper and lower plates  42 ,  43 ,  44 , such that the upper and lower plates  42 ,  43 ,  44  are clamped by a clamping device (not shown), or a heavy object is placed on the upper and lower plates  42 ,  43 ,  44 . By this measure, the adhesive protective sheets  45 ,  46 , together with the upper and lower plates  42 ,  43 ,  44 , are pressurized (given pressure) under a suitable pressurizing force. Moreover, the adhesive protective sheets  45 ,  46 , together with the upper and lower plates  42 ,  43 ,  44 , are heated by a heating means, such as a baking furnace (heating furnace), to a suitable temperature at which the adhesive protective sheets  45 ,  46  are melted and adhered. The pressurizing force and the heating temperature differ according to the type of the adhesive protective sheets  45 ,  46 . For example, the heating temperature is usually several hundred degrees centigrade.  
      As a result, the upper plate  42  and the lower plate  44  are bonded together by the adhesive protective sheet  45 , and the upper plate  43  and the lower plate  44  are bonded together by the adhesive protective sheet  46 .  
      Concretely, at the portion of joining between the upper and lower plates  42  and  44 , namely, at a portion where the adhesive protective sheet  45  contacts the joining surface  42   c  of the upper plate  42  and the joining surface  44   b  of the lower plate  44  (i.e., the portion other than the portion corresponding to the groove  52  formed in the upper plate  42 ), the upper and lower plates  42  and  44  are bonded by the adhesive protective sheet  45 . In the non-joining portion of the upper and lower plates  42  and  44 , namely, the portion corresponding to the groove  52  formed in the upper plate  42 , the adhesive protective sheet  45  is fusion bonded to the joining surface  44   b  of the lower plate  44 , coating or lining the joining surface  44   b.  Thus, the adhesive protective sheet  45  protects the relevant portion of the lower plate  44  from a corrosive fluid flowing in the groove  52 .  
      Similarly, at the portion of joining between the upper and lower plates  43  and  44 , namely, at a portion where the adhesive protective sheet  46  contacts the joining surface  43   c  of the upper plate  43  and the joining surface  44   c  of the lower plate  44  (i.e., the portion other than the portion corresponding to the groove  52  formed in the upper plate  43 ), the upper and lower plates  43  and  44  are bonded by the adhesive protective sheet  46 . In the non-joining portion of the upper and lower plates  43  and  44 , namely, the portion corresponding to the groove  52  formed in the upper plate  43 , the adhesive protective sheet  46  is fusion bonded to the joining surface  44   c  of the lower plate  44 , coating or lining the joining surface  44   c.  Thus, the adhesive protective sheet  46  protects the relevant portion of the lower plate  44  from a corrosive fluid flowing in the groove  52 .  
      Then, the instruments  47  are placed on the upper plates  42 ,  43 , and they are clamped by the bolts  48 ,  50  and the nuts  49 ,  51  for fixing, whereby sufficient strength of the bonding surfaces can be ensured. Furthermore, if it is necessary to enhance the bond strength between the upper plates  42 ,  43  and the lower plate  44  because the fluids flowing in the grooves  52  are set at a high pressure, the upper and lower plates  42 ,  43 ,  44  and the adhesive protective sheets  45 ,  46  may be clamped together by the bolts  48  and the nuts  49  via suitable metal plates  54  disposed on the upper plates  42 ,  43  for the purpose of reinforcement. In this case, it is vital that the bolt holes  42   b,    43   b,    45   a,    46   a  evade the grooves  52 .  
      As described above, the channel-incorporating pedestal  41  of the present Embodiment 2 comprises the upper and lower plates  42 ,  43  and  44  joined together, with the lower plate  44  being interposed between the upper plates  42  and  43 , incorporates the grooves  52 , which are formed on the joining surfaces  42   c,    43   c  of the upper plates  42 ,  43 , as the channels for fluids, brings the groove  52  of the upper plate  42  into communication with the instruments  47 , which are placed on the surface  42   a  of the upper plate  42 , via the communication holes  53  formed in the upper plate  42 , and brings the groove  52  of the upper plate  43  into communication with the instruments  47 , which are placed on the surface  43   a  of the upper plate  43 , via the communication holes  53  formed in the upper plate  43 . This channel-incorporating pedestal is characterized in that the upper plates  42 ,  43  comprise the anticorrosive material, the lower plate  44  comprises the metallic material, the upper plate  42  and the lower plate  44  are bonded together by the adhesive protective sheet  45  interposed between the upper and lower plates  42  and  44 , the adhesive protective sheet  45  having a lower melting point than the melting points of the upper and lower plates  42 ,  43 ,  44 , and being thermoplastic and anticorrosive, and the upper plate  43  and the lower plate  44  are bonded together by the adhesive protective sheet  46  interposed between the upper and lower plates  43  and  44 , the adhesive protective sheet  46  having a lower melting point than the melting points of the upper and lower plates  42 ,  43 ,  44 , and being thermoplastic and anticorrosive.  
      The method for producing the channel-incorporating pedestal  41  of the present Embodiment 2 is a method for producing a channel-incorporating pedestal, which comprises the upper and lower plates  42 ,  43 ,  44  joined together, with the lower plate  44  being interposed between the upper plates  42  and  43 , incorporates the grooves  52 , formed on the joining surfaces  42   c,    43   c  of the upper plates  42 ,  43 , as the channels for fluids, brings the groove  52  into communication with the instruments  47 , placed on the surface  42   a  of the upper plate  42 , via the communication holes  53  formed in the upper plate  42 , and brings the groove  52  into communication with the instruments  47 , placed on the surface  43   a  of the upper plate  43 , via the communication holes  53  formed in the upper plate  43 . This method is characterized by using the anticorrosive material as the upper plates  42 ,  43 , using the metallic material as the lower plate  44 , and pressurizing and heating the upper and lower plates  42 ,  43 ,  44 , with the adhesive protective sheet  45  being interposed between the upper plate  42  and the lower plate  44 , the adhesive protective sheet  45  having a lower melting point than the melting points of the upper and lower plates  42 ,  43 ,  44 , and being thermoplastic and anticorrosive, and with the adhesive protective sheet  46  being interposed between the upper plate  43  and the lower plate  44 , the adhesive protective sheet  46  having a lower melting point than the melting points of the upper and lower plates  42 ,  43 ,  44 , and being thermoplastic and anticorrosive, to melt the adhesive protective sheets  45 ,  46 , thereby bonding the upper plate  42  and the lower plate  44  together by the adhesive protective sheet  45 , and bonding the upper plate  43  and the lower plate  44  together by the adhesive protective sheet  46 .  
      According to the present Embodiment 2, the upper plates  42 ,  43  having the grooves  52  and the communication holes  53  formed therein comprise the anticorrosive material, and the lower plate  44  comprising the metallic material is protected by the anticorrosive adhesive protective sheets  45 ,  46 . Thus, the upper and lower plates  42 ,  43 ,  44  have corrosion resistance, for example, to the corrosive fluid flowing in the grooves  52 . Furthermore, the lower plate  44  comprises the metallic material, so that the lower plate  44  can ensure the mechanical strength of the channel-incorporating pedestal  41 . If further strength is needed, the further strength can be easily obtained simply by increasing the wall thickness of the lower plate  44 . Moreover, the strength can be easily enhanced by clamping the upper and lower plates  42 ,  43 ,  44  by the bolts  48  and the nuts  49  via the metal plate  54 .  
      Besides, corrosion prevention can be easily performed simply by bonding the upper and lower plates  42 ,  43  and  44  together by the adhesive protective sheets  45 , 46 . For example, the lower plate  44  has the simplest flat surface. Thus, merely by applying a suitable pressurizing force and a suitable heating temperature to the adhesive protective sheets  45 ,  46 , satisfactory bonding force and anticorrosive performance can be ensured easily. Consequently, as compared with a conventional corrosion prevention measure such as aluminum oxide film coating, the channel-incorporating pedestal  41  with anticorrosive properties can be produced easily, and cost reduction can be achieved. If a synthetic resin such as PTFE is used as the material for the upper plate  42 , the groove  52  and the communication holes  53  can be easily formed by a method such as machining, injection molding, or die casting. Thus, further cost reduction can be achieved. Furthermore, a multistage channel-incorporating pedestal, which is compact and lightweight, can be produced.  
      As described above, the present invention relates to a channel-incorporating pedestal, which is useful when applied in preventing the occurrence of cracks in weld lines surrounding the groove and the corrosion of the weld lines to maintain the sealing function of the weld lines.  
      The invention thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.