Patent Publication Number: US-6660088-B2

Title: Pressure infiltrating apparatus for infiltrating fiber bundle with metal

Description:
BACKGROUND OF INVENTION 
     1. Field of Invention 
     The present invention relates to a pressure infiltrating apparatus for infiltrating a fiber bundle with a metal to manufacture a fiber reinforced metal composite wire having a fiber bundle infiltrated with a molten metal and an outer surface of the fiber bundle coated with the metal, and more particularly to an orifice structure of the pressure infiltrating apparatus for positioning the fiber bundle around the fiber reinforced metal composite wire. 
     2. Related Art 
     Conventionally, a fiber reinforced metal composite wire is used as an electric wire excellent in durability and reliability. The fiber reinforced metal composite wire is obtained by infiltrating an inorganic fiber bundle such as a carbon fiber, a ceramic fiber or a metal fiber with a molten metal and the amount of the molten metal held on the inorganic fiber bundle is increased so that the durability and reliability can be more enhanced. 
     Conventionally, U.S. Pat. No. 5,736,199 has described a method of manufacturing a fiber reinforced metal composite wire for holding more molten metals in the fiber bundle in which the metal is infiltrated in a fiber of the inorganic fiber bundle at a predetermined pressure. The manufacturing method is carried out by using a metal infiltrating apparatus  30  shown in FIG.  3 . 
     Referring to FIG. 3, in a metal infiltrating apparatus  30 , an inorganic fiber bundle  37  to be inserted in a pressure chamber  31  and a bath container  32  is immersed in a molten metal  33  stored in the bath container  32  through orifices  34 ,  35  and  36  in the pressure chamber  31  filled with an inert gas, thereby infiltrating the inorganic fiber bundle  37  with a metal and coating the outer surface of the inorganic fiber bundle  37  with the metal. 
     The orifices  34 ,  35  and  36  include the entering orifice  34  for inserting the inorganic fiber bundle  37  from the outside of the pressure chamber  31  on the fiber bundle inlet side into the bath container  32 , the exit orifice  35  for inserting the inorganic fiber bundle  37  from the inside of the pressure chamber  31  to the outside of the pressure chamber  31  on the fiber bundle outlet side, and the intermediate orifice  36  provided between the entering orifice  34  and the exit orifice  35  and serving to insert the inorganic fiber bundle  37  from the bath container  32  into the pressure chamber  31 . 
     In the conventional metal infiltrating apparatus  30 , in the case in which the fiber reinforced metal composite wire is to be thinned, there is a possibility that the inorganic fiber bundle  37  might be flexed or moved between the entering orifice  34  and the intermediate orifice  36  in the bath container  32 . 
     Accordingly, there is a problem in that it is hard to concentrically coat the periphery of the inorganic fiber bundle  37  with a metal and to position the inorganic fiber bundle  37  on the center of the coating metal, that is, the center of the fiber reinforced metal composite wire. 
     SUMMARY OF THE INVENTION 
     The invention has an object to provide a pressure infiltrating apparatus for infiltrating a fiber bundle with a metal which can reduce a space between an inlet side orifice and an intermediate orifice, thereby reliably preventing such a drawback that a fiber bundle is flexed between the inlet side orifice and the intermediate orifice in a bath container and arranging the fiber bundle on the center of a coating metal. 
     The problem of the invention can be solved by a pressure infiltrating apparatus for inserting a fiber bundle through an orifice in a molten metal stored in a bath container in a pressure chamber filled with an inert gas, thereby infiltrating the fiber bundle with the molten metal and coating an outer surface of the fiber bundle with the molten metal, 
     wherein the orifice includes an inlet side orifice for inserting the fiber bundle from a fiber bundle inlet side of the pressure chamber into the bath container, an outlet side orifice for leading a fiber reinforced metal composite wire infiltrated with the molten metal from a fiber bundle outlet side of the pressure chamber to an outside of the pressure chamber, and an intermediate orifice provided between the inlet side orifice and the outlet side orifice and serving to insert the fiber reinforced metal composite wire from the bath container into the pressure chamber, and 
     a tip shape on the intermediate orifice side of the inlet side orifice is caused to be convex and an inside shape of a tip on the inlet side orifice side of the intermediate orifice is caused to be concave corresponding to the tip shape of the inlet side orifice. 
     According to the pressure infiltrating apparatus for infiltrating a fiber bundle with a metal which has the structure described above, the tip shape on the intermediate orifice side of the inlet side orifice is caused to be convex and the tip shape of an insertion hole on the inlet side orifice side of the intermediate orifice is caused to be concave corresponding to the tip shape of the inlet side orifice. 
     Accordingly, the fiber bundle is inserted into the bath container through the inlet side orifice and is caused to come in contact with a molten metal in the bath container under pressurization of the inert gas from the inlet side orifice to the intermediate orifice. Consequently, the fiber bundle is infiltrated with the molten metal and the outer surface thereof is coated with the molten metal. 
     In this case, the space between the inlet side orifice and the intermediate orifice is reduced so that the fiber bundle can be reliably prevented from being flexed between the inlet side orifice and the intermediate orifice in the bath container and the fiber bundle can be positioned on the center of the coating metal. 
     Moreover, the fiber bundle is simply exposed to the molten metal in a minimum time required for the infiltration and coating of the molten metal so that the damage to the fiber bundle caused by a reaction to the molten metal can be relieved. 
     In the case in which the space between the inlet side orifice and the intermediate orifice is reduced, there is a possibility that the fluidity of the molten metal between the inlet side orifice and the intermediate orifice might be deteriorated and the infiltration might not be carried out sufficiently. However, since the tip shape on the intermediate orifice side of the inlet side orifice is convex and the tip shape on the inlet side orifice side of the intermediate orifice is concave corresponding to the shape of the inlet side orifice, the fluidity of the molten metal between the inlet side orifice and the intermediate orifice can be ensured and the infiltration into the fiber bundle can be carried out sufficiently. 
     Moreover, the fiber bundle infiltrated and coated with the molten metal is inserted from the intermediate orifice into the pressure chamber. The fiber bundle in the pressure chamber is led out of the pressure chamber through the outlet side orifice after the molten metal with which the fiber bundle is infiltrated and coated is cooled. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 is a schematic sectional view showing an embodiment of a pressure infiltrating apparatus for infiltrating a fiber bundle with a metal according to the invention, 
     FIG. 2 is a sectional view showing a fiber reinforced metal composite wire formed by the pressure infiltrating apparatus in FIG. 1, and 
     FIG. 3 is a schematic sectional view showing a conventional pressure infiltrating apparatus. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     An embodiment of a pressure infiltrating apparatus for infiltrating a fiber bundle with a metal according to the invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a schematic sectional view showing the pressure infiltrating apparatus for infiltrating a fiber bundle with a metal according to the embodiment of the invention, and FIG. 2 is a sectional view showing a fiber reinforced metal composite wire formed by the pressure infiltrating apparatus in FIG.  1 . 
     As shown in FIGS. 1 and 2, a pressure infiltrating apparatus  20  according to the embodiment immerses an inorganic fiber bundle  10  to be inserted into a pressure chamber  21  and a bath container  22  through orifices  23 ,  24  and  25  in molten metal  11  stored in the bath container  22  in the pressure chamber  21  filled with an inert gas. Consequently, the inorganic fiber bundle  10  is infiltrated with the metal and the outer surface thereof is coated with the metal so that a fiber reinforced metal composite wire  12  is formed. 
     More specifically, in the pressure infiltrating apparatus  20 , the inorganic fiber bundle  10  is continuously fed from each feeding side drum  27  upward in FIG. 1 with the rotation of a winding side drum  26  and is converged through a throttling portion  28  such as a die, and is inserted into the pressure chamber  21  and the bath container  22  through each of the orifices  23 ,  24  and  25 . Consequently, the pressure infiltrating apparatus  20  immerses the inorganic fiber bundle  10  in the molten metal  11  at a predetermined pressure, and impregnates the inorganic fiber bundle  10  with the metal and concentrically coats the outer surface of the inorganic fiber bundle  10  with the metal. Examples of the inorganic fiber include a fiber such as carbon, boron or silicon carbide and a metal fiber such as aluminum oxide. 
     Moreover, an inert gas such as argon, nitrogen or helium is supplied from a gas supply source  29  to the pressure chamber  21  to be filled at a predetermined pressure. 
     Furthermore, the bath container  22  is provided in the pressure chamber  21  and stores the molten metal  11  such as copper, aluminum, magnesium, silver or alloys. A heater  22   a  is provided in the vicinity of the outer peripheral surface of the bath container  22 . The heater  22   a  heats the molten metal  11  stored in the bath container  22  and keeps the molten metal  11  warm. 
     Moreover, the orifices  23 ,  24  and  25  include the inlet side orifice  23 , the outlet side orifice  24  and the intermediate orifice  25 . The inlet side orifice  23  inserts the inorganic fiber bundle  10  from the outside of the pressure chamber  21  on the inorganic fiber bundle inlet side (the lower side in FIG. 1) into the bath container  22 . The outlet side orifice  24  inserts the inorganic fiber bundle  10  from the inside of the pressure chamber  21  to the outside of the pressure chamber  21  on the inorganic fiber bundle outlet side (the upper side in FIG.  1 ). The intermediate orifice  25  is provided between the inlet side orifice  23  and the outlet side orifice  24 , and inserts the inorganic fiber bundle  10  from the inside of the bath container  22  to the inside of the pressure chamber  21 . 
     The orifices  23 ,  24  and  25  are formed of at least one of graphite, tantalum, stainless, tungsten, inconel, molybdenum, platinum, sintered zirconia ceramic and an aluminum ceramics based material which less react to the molten metal  11  and the inorganic fiber bundle  10  mechanically and chemically. Consequently, the durability of the orifices  23 ,  24  and  25  themselves can be maintained and the inorganic fiber bundle  10  in the orifices  23 ,  24  and  25  can be prevented from being broken. 
     A tip (an upper end in FIG. 1) on the intermediate orifice  25  side in the inlet side orifice  23  is formed to take a conically tapered convex shape. Moreover, the tip portion (lower end in FIG. 1) of an insertion hole on the inlet side orifice  23  side in the intermediate orifice  25  is formed to take a conical concave shape having a diameter gradually increased toward the tip (lower end in FIG. 1) corresponding to the tapered convex shape of the inlet side orifice  23 . 
     By the tapered convex shape on the upper end of the inlet side orifice  23  shown in FIG.  1  and the concave shape on the lower end of the insertion hole in the intermediate orifice  25  shown in FIG. 1, a space A between the inlet side orifice  23  and the intermediate orifice  25  can be set to be small without damaging the fluidity of the molten metal  11  between the inlet side orifice  23  and the intermediate orifice  25  in the bath container  22 . 
     Accordingly, the inorganic fiber bundle  10  can be reliably prevented from being flexed between the inlet side orifice  23  and the intermediate orifice  25  in the bath container  22  and a time required for exposing the inorganic fiber bundle  10  to the molten metal  11  is minimized for the infiltration and coating of the metal. Moreover, the inserting property of the inorganic fiber bundle  10  can be maintained to be excellent. 
     Moreover, a plurality of (six in FIG. 1) feeding side drums  27  are provided on the outside of the pressure chamber  21  at the inlet side of the inorganic fiber bundle  10  through the inlet side orifice  23 . Each of the feeding side drums  27  feeds the inorganic fiber bundle  10  wound around the outer periphery through rotation around a rotary shaft  27   a  and twists a plurality of (six in FIG. 1) inorganic fiber bundles  10  thus fed through revolution around a virtual center line B. 
     Furthermore, the winding side drum  26  is provided on the outside of the pressure chamber  21  at the outlet side of the inorganic fiber bundle  10  through the outlet side orifice  24 . The winding side drum  26  winds the fiber reinforced metal composite wire  12  upon the outer periphery through rotation around a rotary shaft  26   a.    
     Description will be given to the function of the pressure infiltrating apparatus for infiltrating a fiber bundle with a metal according to the embodiment. The inorganic fiber bundle  10  in the pressure infiltrating apparatus  20  is continuously fed from each feeding side drum  27  with the rotation of the winding side drum  26 , is converged through the throttling portion  28  and is then introduced into the bath container  22  through the inlet side orifice  23 . 
     The inorganic fiber bundle  10  in the bath container  22  is immersed in the molten metal  11  under the pressurization of the inert gas supplied from the gas supply source  29  while it gets out of the tip (upper end in FIG. 1) of the inlet side orifice  23  into the intermediate orifice  25 . 
     Consequently, the inorganic fiber bundle  10  is infiltrated with the molten metal and the outer surface thereof is coated with the molten metal. 
     In this case, the space A between the inlet side orifice  23  and the intermediate orifice  25  is set to be small. Consequently, it is possible to reliably prevent the inorganic fiber bundle  10  from being flexed between the inlet side orifice  23  and the intermediate orifice  25  in the bath container  22 . 
     Accordingly, the inorganic fiber bundle  10  is formed to be arranged on the center of a coating metal  13 , that is, the center of the fiber reinforced metal composite wire  12 . Moreover, the inorganic fiber bundle  10  is simply exposed to the molten metal  11  in a minimum time necessary for the infiltration and coating of the metal so that the damage to the inorganic fiber bundle  10  caused by a reaction to the molten metal  11  can be relieved. 
     In the case in which the space A between the inlet side orifice  23  and the intermediate orifice  25  is reduced, the fluidity of the molten metal  11  between the inlet side orifice  23  and the intermediate orifice  25  is deteriorated. Due to the deterioration in the fluidity of the molten metal  11 , usually, the infiltration in the fiber bundle cannot be carried out sufficiently. 
     In the pressure infiltrating apparatus  20  according to the embodiment, however, the upper end of the inlet side orifice  23  in FIG. 1 takes a tapered convex shape and the lower end of the insertion hole in the intermediate orifice  25  in FIG. 1 takes a concave shape having a diameter gradually increased corresponding to the convex shape of the inlet side orifice  23 . Consequently, it is possible to maintain the fluidity of the molten metal  11  between the inlet side orifice  23  and the intermediate orifice  25 . 
     The inorganic fiber bundle  10  infiltrated and coated with the metal is inserted through the intermediate orifice  25  and an extra portion of the metal coating the outer surface is scraped off for molding, and the inorganic fiber bundle  10  is inserted from the intermediate orifice  25  into the pressure chamber  21 . The molten metal  11  with which the inorganic fiber bundle  10  in the pressure chamber  21  is infiltrated and coated is cooled to form the fiber reinforced metal composite wire  12 . 
     Then, the fiber reinforced metal composite wire  12  gets out of the pressure chamber  21  though the outlet side orifice  24  and is wound upon the winding side drum  26 . 
     According to the pressure infiltrating apparatus for infiltrating a fiber bundle with a metal according to the embodiment, as described above, the upper end of the inlet side orifice  23  in FIG. 1 is formed to take the tapered convex shape and the lower end of the insertion hole of the intermediate orifice  25  in FIG. 1 is formed to take a concave shape having a diameter gradually increased corresponding to the convex shape of the inlet side orifice  23 . Therefore, it is possible to set the space A between the inlet side orifice  23  and the intermediate orifice  25  to be small without damaging the fluidity of the molten metal  11  between the inlet side orifice  23  and the intermediate orifice  25  in the bath container  22 . 
     Also in the case in which the fiber reinforced metal composite wire  12  is to be particularly thinned, accordingly, it is possible to reliably prevent the inorganic fiber bundle  10  from being flexed or moved between the inlet side orifice  23  and the intermediate orifice  25  in the bath container  22 . Consequently, the periphery of the inorganic fiber bundle  10  can be concentrically coated with the metal and the inorganic fiber bundle  10  can be provided on the center of the coating metal  13 , that is, the center of the fiber reinforced metal composite wire  12 . 
     Moreover, a time required for exposing the inorganic fiber bundle  10  to the molten metal  11  can be minimized for the infiltration and coating of the metal, and the damage to the inorganic fiber bundle  10  caused by the reaction to the molten metal  11  can be minimized. 
     Consequently, it is possible to obtain the fiber reinforced metal composite wire  12  which is thinned with a light weight, a high mechanical strength, an excellent electrical characteristic and a high quality. 
     JP-A-6-158197 has disclosed an infiltrating apparatus for immersing a plurality of long fiber bundles in a molten metal, and infiltrating the fiber with the molten metal and converging the fiber in the molten metal in order to manufacture a composite material, which is not shown. In the infiltrating apparatus, the long fiber bundle is converged and the extra molten metal of the composite material is scraped off, and furthermore, the external shape of the composite material is molded through the throttle portion such as a nozzle provided in the molten metal. 
     In the infiltrating apparatus, the throttling portion such as a nozzle is provided in the molten metal, and it is hard to converge the fiber in the central part of the composite material and the outer surface is to be coated with a metal separately. More specifically, it is necessary to always maintain the tension of the fiber to be constant and to center the fiber on the throttling portion in order to converge the fiber on the central part of the composite material. However, the conventional publication has not described means for centering the fiber on the throttling portion. 
     It is technically hard to concentrically coat the fiber with a metal if the means for centering the fiber is not close to the center of the throttling portion. For this reason, it is hard to provide the means for centering the fiber in the infiltrating apparatus in which the throttle portion is provided in the molten metal. 
     According to the pressure infiltrating apparatus  20  in accordance with the embodiment, the problems of the conventional infiltrating apparatus can be solved, the inorganic fiber bundle  10  can be positioned on the center of the coating metal  13  and the fiber reinforced metal composite wire  12  having the inorganic fiber bundle  10  arranged on the center can be obtained. 
     According to the pressure infiltrating apparatus for infiltrating a fiber bundle with a metal in accordance with the invention, as described above, the tip shape on the intermediate orifice side of the inlet side orifice is caused to be convex and the inside shape of the tip on the inlet side orifice side of the intermediate orifice is caused to be concave corresponding to the tip shape of the inlet side orifice. 
     Accordingly, the space between the inlet side orifice and the intermediate orifice can be reduced, and it is possible to reliably eliminate such a drawback that the fiber bundle is flexed between the inlet side orifice and the intermediate orifice in the bath container and to arrange the fiber bundle on the center of the coating metal. Consequently, it is possible to obtain a fiber reinforced metal composite wire which is thinned with a light weight, a high mechanism strength, an excellent electrical characteristic and a high quality.