Patent Publication Number: US-2021183559-A1

Title: Current introduction terminal structure and electromagnet device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation Application of No. PCT/JP2019/038712, filed on Oct. 1,2019, and the PCT application is based upon and claims the benefit of priority from Japanese Patent Application No. 2018-204634, filed on Oct. 31,2018, the entire contents of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     Embodiments of the present invention relate to a current introduction terminal structure, which has a current introduction terminal to be electrically connected to a conductive member formed by bundling a plurality of wires, and an electromagnet device that uses this current introduction terminal structure. 
     BACKGROUND 
       FIG. 4  is a cross-sectional view schematically illustrating a conventional current introduction terminal structure. In this conventional current introduction terminal structure  100 , a cooling-water pipe  104  is coaxially disposed inside a tubular current introduction terminal  101  in which one side is closed, a conductive member  103  is electrically connected to the tip of the current introduction terminal  101  via a crimp terminal  102 , and a cooling-water supply-pipe  106  is connected to the cooling-water pipe  104  via a cooling-water joint  105 . Further, the conductive member  103  is electrically connected to an electromagnet that is the destination of current supply. 
     The current introduction terminal  101  is fixed to a connection flange  108  via an insulating member  107  by brazing, and the connection flange  108  is fastened to an electromagnet housing  110  with a bolt  109 . Further, a second current introduction member  112  is fixed to the current introduction terminal  101  by brazing, and as shown in  FIG. 5 , a first current introduction member  111  is fastened to the second current introduction member  112  with bolts  113  and hexagon nuts  114 . 
     The conductive member  103  is formed by bundling a plurality of wires  115  made of a conductive material, and is fastened to the closed tip of the current introduction terminal  101  with a bolt  116  via the crimp terminal  102  as described above. The conductive member  103  is disposed in an internal space  122  which is surrounded by the electromagnet housing  110  and a housing lid  121  for closing the opening of the electromagnet housing  110 . Electric current from a power supply (not shown) is led to the conductive member  103  via the first current introduction member  111 , the second current introduction member  112 , the current introduction terminal  101 , and the crimp terminal  102 , and is supplied from this conductive member  103  to the electromagnet that is the destination of current supply. 
     The cooling-water pipe  104  is disposed in the tubular current introduction terminal  101  such that the inside of the cooling-water pipe  104  serves as a cooling-water supply-channel  117  and the space between the cooling-water pipe  104  and the current introduction terminal  101  serves as a cooling-water drainage-channel  118 . Further, the cooling-water pipe  104  is fixed to the cooling-water joint  105  by caulking, and the cooling-water supply-pipe  106  is also fixed to the cooling-water joint  105  by caulking. Thereby, the cooling-water pipe  104  in the current introduction terminal  101  is connected to the cooling-water supply-pipe  106  made of an insulating material via the cooling-water joint  105 . 
     Further, the current introduction terminal  101  is fixed to the cooling-water joint  119  by screwing or brazing, and a cooling-water drain-pipe  120  and the cooling-water pipe  104  are fixed to the cooling-water joint  119  by caulking. Consequently, the cooling-water drainage-channel  118  between the cooling-water pipe  104  and the current introduction terminal  101  is connected to the cooling-water drain-pipe  120  made of an insulating material via the cooling-water joint  119 . 
     Thus, the cooling water from the cooling-water supply-pipe  106  flows through the cooling-water supply-channel  117  in the cooling-water pipe  104  via the cooling-water joint  105 , then reverses at the tip of the cooling-water pipe  104  so as to flow into the cooling-water drainage-channel  118 , and is drained from the cooling-water drain-pipe  120  via the cooling-water joint  119 . In this manner, the conductive member  103  formed by bundling a plurality of wires  115  is indirectly cooled by the cooling water via the crimp terminal  102  and the current introduction terminal  101 . 
     PRIOR ART DOCUMENT 
     Patent Document 
     [Patent Document 1] JP 2013-115281 A 
     [Patent Document 2] Japanese Unexamined Utility Model Application Publication No. H04-136897 
     SUMMARY 
     Problems to be Solved by Invention 
     As described above, the conductive member  103  formed by bundling a plurality of wires  115  is indirectly cooled by the cooling water flowing inside the current introduction terminal  101  via the crimp terminal  102  and the current introduction terminal  101 . Thus, cooling of the conductive member  103  depends on the thermal conductivity of the crimp terminal  102  and the current introduction terminal  101 . Hence, even if the diameter of each of the current introduction terminal  101  and the cooling-water pipe  104  is increased to increase the amount of the cooling water, the cooling efficiency of the conductive member  103  is insufficient in some cases and there is a possibility that a large electric current cannot be supplied to the conductive member  103 . 
     In view of the above-described problem, an object of embodiments of the present invention is to provide a current introduction terminal structure and an electromagnet device, both of which can improve cooling efficiency of a conductive member, which is formed by bundling a plurality of wires and to which electric current is led from a current introduction terminal. 
     Solution to Problem 
     A current introduction terminal structure according to one embodiment of the present invention has a structure in which electric current is led from a current introduction terminal to a conductive member formed by bundling a plurality of wires, and is configured in such a manner that the conductive member and the current introduction terminal electrically connected to the conductive member are disposed in a casing for storing cooling water and are immersed in the cooling water. 
     An electromagnet device according to one embodiment of the present invention is configured in such a manner that the above-described current introduction terminal structure is disposed between an electromagnet and a power source to electrically connect the electromagnet to the power source. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a cross-sectional view schematically illustrating a current introduction terminal structure according to one embodiment. 
         FIG. 2  is a view on the arrow II in  FIG. 1 . 
         FIG. 3  is a cross-sectional view schematically illustrating an electromagnet device according to one embodiment. 
         FIG. 4  is a cross-sectional view schematically illustrating a conventional current introduction terminal structure. 
         FIG. 5  is a view on the arrow V in  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments of the present invention will be described by referring to the drawings. 
       FIG. 1  is a cross-sectional view schematically illustrating a current introduction terminal structure according to one embodiment. The current introduction terminal structure  10  shown in  FIG. 1  leads electric current from a power source (not shown) to a current introduction terminal  12  via a current introduction member  11 , and supplies the electric current to, for example, an electromagnet (not shown), which is the destination of current supply, via a conductive member  13  electrically connected to the current introduction terminal  12 . The current introduction terminal  12  and the conductive member  13  are disposed in a casing  14  in which cooling water W such as pure water having electric non-conductance is stored (for example, filled), and a cooling-water supply-pipe  15  and a cooling-water drain-pipe  16  are attached to the casing  14 . 
     The casing  14  includes: an electromagnet housing  17  as a casing body for accommodating an electromagnet (not shown); a housing lid  18  that closes the opening of the electromagnet housing  17 ; and a connection flange  19  as a connecting member to be fixed and attached to the electromagnet housing  17  by screwing or an adhesive. An internal space  19 A of the connection flange  19  communicates with an internal space  17 A of the electromagnet housing  17  by a communication port  20  formed in the electromagnet housing  17 . Further, the housing lid  18  is fastened to the electromagnet housing  17  with a bolt  23 . The internal space  17 A of the electromagnet housing  17  is kept water-sealed by an O-ring  30  interposed between the electromagnet housing  17  and the housing lid  18 . In particular, the electromagnet housing  17  is made of an insulating material. 
     The current introduction member  11  includes a first current introduction member  21  and a second current introduction member  22 , both of which are made of a conductive material. The first current introduction member  21  is electrically connected to the power supply side. Further, the first current introduction member  21  is fastened to the second current introduction member  22  with, for example, bolts  24  and hexagon nuts  25  so as to be fixed. The second current introduction member  22  is electrically connected to the current introduction terminal  12  as described below, and thereby, the electric current from the power supply is led to the current introduction terminal  12  via the first current introduction member  21  and the second current introduction member  22 . 
     The current introduction terminal  12  is solidly composed of a conductive material and has a tip portion  12 A, a main body portion  12 B, a base end portion  12 C, and a base-end connecting portion  12 D. The base end portion  12 C of the current introduction terminal  12  is fitted into an interdigitation hole  26 , which is formed so as to penetrate the connection flange  19 , and is fixed to the connection flange  19  with a C-shaped retaining ring  27 . Further, one or a plurality of peripheral grooves  28  are formed on the outer periphery of the base end portion  12 C of the current introduction terminal  12 , and an O-ring  29  is attached to the peripheral groove (s)  28 . The O-ring  29  contacts the inner surface of the interdigitation hole  26  of the connection flange  19 , and thereby, the internal space  19 A of the connection flange  19  is kept water-sealed. 
     The base end portion  12 C of the current introduction terminal  12  is fixed to the connection flange  19 . Accordingly, the tip portion  12 A and the main body portion  12 B of the current introduction terminal  12  are disposed in the internal space  19 A of the connection flange  19 , the communication port  20  of the electromagnet housing  17 , and the internal space  17 A of the electromagnet housing  17  so as to be fully immersed in the cooling water W that does not conduct electricity. Further, the base-end connecting portion  12 D of the current introduction terminal  12  is disposed outside the connection flange  19 . 
     The base-end connecting portion  12 D of the current introduction terminal  12  is inserted into a connection hole  31  formed in the second current introduction member  22 , and is fastened to the second current introduction member  22  with the bolt  32  and the hexagon nut  33  shown in  FIG. 2 . As a result, the current introduction terminal  12  is electrically connected to the second current introduction member  22 . When the bolt  32  and the hexagon nut  33  are loosened, under the state where the tip portion  12 A and the main body portion  12 B of the current introduction terminal  12  and the conductive member  13  described below are fully immersed in the cooling water W in the internal space  17 A of the electromagnet housing  17  and the internal space  19 A of the connection flange  19 , the second current introduction member  22  is configured such that its mounting angle e can be adjusted with respect to the current introduction terminal  12  with the base-end connecting portion  12 D of the current introduction terminal  12  as the rotation axis. 
     In addition, the base-end connecting portion  12 D of the current introduction terminal  12  is fastened to the second current introduction member  22  with the bolt  32  and the hexagon nut  33 . Consequently, under the state where the tip portion  12 A and the main body portion  12 B of the current introduction terminal  12  and the conductive member  13  described below are fully immersed in the cooling water W in the internal space  17 A of the electromagnet housing  17  and the internal space  19 A of the connection flange  19 , the second current introduction member  22  is detachably attached to the current introduction terminal  12 . 
     The conductive member  13  is formed by bundling a plurality of wires  34  made of a conductive material. This conductive member  13  is electrically connected to the tip portion  12 A of the current introduction terminal  12  by, for example, brazing. The conductive member  13  is also electrically connected to an electromagnet (not shown) which is the destination of current supply. Thus, the electric current from the power supply is led to the conductive member  13  via the first current introduction member  21 , the second current introduction member  22 , and the current introduction terminal  12 , and is supplied from this conductive member  13  to the destination of current supply (for example, the electromagnet). Further, the conductive member  13  is disposed in the internal space  17 A of the electromagnet housing  17  and is fully immersed in the cooling water W filled in the internal space  17 A. 
     The cooling-water supply-pipe  15  is connected to the connection flange  19  via a cooling-water joint  35 . Further, the cooling-water drain-pipe  16  is connected to the housing lid  18  via a cooling-water joint  36 . The cooling-water joint  35  is fixed to the connection flange  19  by, for example, screwing. The cooling-water joint  36  is fixed to the housing lid  18  by, for example, screwing. The cooling-water supply-pipe  15  is fixed to the cooling-water joint  35  by, for example, caulking. The cooling-water drain-pipe  16  is fixed to the cooling-water joint  36  by, for example, caulking. Of these, the cooling-water supply-pipe  15  and the cooling-water drain-pipe  16  are composed of an insulating material. 
     The cooling water W supplied from the cooling-water supply-pipe  15  flows into the internal space  19 A of the connection flange  19  via the cooling-water joint  35 , passes through the communication port  20  of the electromagnet housing  17  so as to flow into the internal space  17 A of the electromagnet housing  17 , and directly cools the current introduction terminal  12  and the conductive member  13 . The cooling water W after cooling these current introduction terminal  12  and conductive member  13  is drained to the outside from the cooling-water drain-pipe  16  via the cooling-water joint  36 . Since the tip portion  12 A and the main body portion  12 B of the current introduction terminal  12  are disposed in the internal space  19 A of the connection flange  19 , the base-end connecting portion  12 D of the current introduction terminal  12 , which becomes particularly hot, is efficiently cooled by the low-temperature cooling water that has flowed from the cooling-water supply-pipe  15  through the cooling-water joint  35  into the internal space  19 A of the connection flange  19 . 
     Since it is configured as described above, according to the present embodiment, the following effects (1) to (3) are obtained. 
     (1) The conductive member  13  formed by bundling a plurality of wires  34  and the current introduction terminal  12  electrically connected to this conductive member  13  are fully immersed in the cooling water W filled in each of the internal space  17 A of the electromagnet housing  17  and the internal space  19 A of the connection flange  19 , and thus, are directly cooled by the cooling water W. Hence, the cooling efficiency of the conductive member  13  can be particularly improved. Even if the electric current to be supplied to the conductive member  13  is a large current, damage due to heat of the conductive member  13  can be avoided. 
     (2) The tip portion  12 A and the main body portion  12 B of the current introduction terminal  12  are disposed in the internal space  19 A of the connection flange  19  and in the communication port  20  of the electromagnet housing  17 . Further, after the cooling water W sequentially flows from the cooling-water supply-pipe  15  to the internal space  19 A of the connection flange  19  and the communication port  20  of the electromagnet housing  17 , the cooling water W flows sequentially to the internal space  17 A of the electromagnet housing  17  and the cooling-water drain-pipe  16 . As a result, the current introduction terminal  12  can be efficiently and directly cooled by the cooling water W in a low-temperature state, and the cooling efficiency of the current introduction terminal  12  can be improved. 
     (3) Under the state where the current introduction terminal  12  and the conductive member  13  are fully immersed in the cooling water W in the internal space  17 A of the electromagnet housing  17  and the internal space  19 A of the connection flange  19  so as to be directly cooled, the second current introduction member  22  is configured to be adjustable in mounting angle θ with respect to the current introduction terminal  12 , and the second current introduction member  22  is detachably attached to the current introduction terminal  12 . Thus, maintenance of the current introduction terminal structure  10  can be facilitated. 
     The current introduction terminal structure  10  according to the above-described embodiment can be applied to, for example, an electromagnet device shown in  FIG. 3 .  FIG. 3  is across-sectional view schematically illustrating the electromagnet device according to one embodiment. In  FIG. 3 , the same components as those in  FIG. 1  are denoted by the same reference signs to simplify or omit description of the configuration. 
     The electromagnet device  40  shown in  FIG. 3  includes: an electromagnet  41 ; the electromagnet housing  17  that houses this electromagnet  41 ; and the current introduction terminal structure  10  that is disposed in this electromagnet housing  17  and is electrically connected to a power supply  42  and the electromagnet  41  so as to lead electric current. In this electromagnet device  40 , the cooling water W such as pure water having electric non-conductance from a cooling-water circulation device  43  cools the current introduction terminal  12  via the cooling-water supply-pipe  15  and is led to the inside of the electromagnet housing  17 , and the cooling water in the electromagnet housing  17  is returned to the cooling water circulation device  43  via the cooling-water drain-pipe  16 . This structure can provide an electromagnet device that exhibits the above-described effects (1) to (3) similarly to the above-described embodiment. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. These embodiments maybe embodied in a variety of other forms, and various omissions, substitutions, and changes may be made without departing from the spirit of the inventions. These embodiments and their modifications are included in the accompanying claims and their equivalents as well as included in the scope and gist of the inventions.