Abstract:
A method for manufacturing an insert molding having a conductor member in which a part thereof is coated with resin is disclosed. The method comprises the steps of securely supporting a part of the conductor member by a fixation member provided in a holding member, grasping the holding member supporting the conductor member by a mold so as to accommodate a portion of the conductor member where is other than a portion to be utilized as a contact point, injecting the resin into inside of the mold, and coating the conductor member accommodated in the mold integrally with the holding member by the resin.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field of the Invention 
     The present invention relates to a method for manufacturing an insert molding, and particularly relates to a method for manufacturing an insert molding in which a portion of a conductor member other than a contact point can be coated with a thin film surely. 
     2. Description of the Related Art 
     In a terminal  30  for connecting an electric equipment of a car, a pair of bus bars  31  are insert-molded with resin having an insulating characteristic as shown in FIGS.  3 (A) to  3 (C). 
     The bus bars  31  are made into suitable metal plate members having electrical conductivity, and disposed in parallel with each other along the axial direction of identical columnar circumferential surface in the state where the respective end portions of the bus bars  31  have been trued up. These bus bars  31  are projecting outside from a coating  32  in order to make their respective one end portions act as contact points. 
     In manufacturing such a terminal  30 , in connection with coating, it is necessary to keep the relative positions of the bus bars  31 , or the relative positions of the bus bars  31  and a mold accurately because the bus bars  31  are coated with a thin film. 
     Conventionally, thus the terminal  30  was manufactured in a manner such that the longitudinal center portions of the bus bars  31  were grasped between upper and lower mold parts of a mold into which resin is to be injected, and then resin is injected into the mold. 
     In the above-mentioned method for manufacturing the terminal  30 , however, exposed portions  33  which were not coated with the coating  32  were formed because the longitudinal center portions of the bus bars  31  were fixed by the upper and lower mold parts. 
     Therefore, in the thus manufactured terminal  30 , there was a fear that the terminal  30  or other parts were damaged or short-circuited because of the exposed portions  33  of the bus bars  31 . 
     SUMMARY OF THE INVENTION 
     The present invention has been achieved in view of the foregoing problem, and it is an object thereof to provide a method for manufacturing an insert molding in which in a conductor member, that portion of a conductor member other than a contact point can be coated with a thin film surely. 
     In order to achieve the above object, there is provided a method for manufacturing an insert molding having a conductor member in which a part thereof is coated with resin comprising the steps of: securely supporting a part of the conductor member by a fixation member provided in a holding member; grasping the holding member supporting the conductor member by a mold so as to accommodate a portion of the conductor member where is other than a portion to be utilized as a contact point; injecting the resin into inside of the mold; and coating the conductor member accommodated in the mold integrally with the holding member by the resin. 
     In the method for manufacturing the thus configured insert molding, the conductor member is held by a holding member grasped in the mold. Accordingly, it is possible to held the relative positions of the conductor member and the mold when molten resin is injected into the mold. This holding member is integrated with a thin film as the molten resin injected into the mold is solidified, and there is no fear that the holding member projects out from the surface of the thin film. 
     That is, in this method for manufacturing insert molding, the holding member for holding the conductor member is integrated with the thin film, so that partially exposed portions conventionally formed in the conductor member can be eliminated. 
     Preferably, the holding member may be made from the same material as the resin, so that the appearance of insert molding is improved. 
     In the holding member, the fixation portion may be formed substantially into a C-shape so as to be capable of grasping the conductor member. 
     Here, as for the fixation portion, for example, in order to grasp a band-like conductor member, any shape will do so long as the gap size of the fixation portion set to be a little smaller than the thickness size of the conductor member so that the conductor member can be grasped by the elastic deformation of the holding member. 
     In the method, a convex portion may be formed in one of the conductor member and the holding member and engaged with the other member at the time of supporting. 
     Here, as for the convex portion, in the case where the conductor member is, for example, like a band, a protrusion may be formed by pressing the plate of the conductor member, a protrusion may be formed integrally with an end surface when the conductor member is formed by punching, or the like. Then, the protrusion may be engaged with an edge portion of the fixation portion for fixing the conductor member, may be pressed onto the inner surface of the fixation portion, or may be engaged with a concave portion provided in the inner surface of the fixation portion. On the other hand, as for the convex portion provided in the holding member, for example, a protrusion may be formed in the inner surface of the fixation portion for fixing the conductor member. Then, the protrusion may be engaged with a recess portion, a notch, a hole, or the like, formed in the conductor member. 
     In such a method for manufacturing insert molding, a convex portion provided in one of the conductor member and the holding member is engaged with the other. Accordingly, the relative positions of the conductor member and the holding member are kept surely. 
     On the other hand, the fixation portion may be formed as an insertion hole to which the conductor member is inserted. According to this configuration, the conductor member can be fixed surely regardless of the injection speed of molten resin injected into the mold. 
     In addition, the holding member may be formed so as to be brought into face contact with an inner wall face of the mold. According to this configuration, the holding member can be grasped firmly regardless of the injection speed of molten resin injected into the mold. 
     The holding member may be formed so as to be brought into line or point contact with an inner wall face of the mold. According to this configuration, it is possible to reduce the area where the holding member is exposed from the surface of the coating, so that it is possible to improve the appearance of insert moldings. 
     As for the conductor members, a pair of metal band portions adopted in the above-mentioned terminal may be shown by way of example. However, according to the present invention, rod or rectangular conductor members are also supposed, and the conductor members are not required to be identical in shape to each other are not required to be disposed in parallel with each other. In addition, the present invention can be applied not only to the case where two conductor members or more are coated with a thin film, but also to the case where a single conductor member is coated with a thin film. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings: 
     FIG.  1 (A) is a partial perspective view showing an embodiment according to the present invention, 
     FIG.  1 (B) is a partial sectional view of the same, and 
     FIG.  1 (C) is a whole plan view of the same; 
     FIGS.  2 (A) to  2 (F) are model diagrams showing another embodiments of the present invention; and 
     FIG.  3 (A) is a sectional view showing a conventional insert molding, 
     FIG.  3 (B) is a plan view of the same, and 
     FIG.  3 (C) is a rear view of the same. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     One preferred embodiment of the present invention will be described below in detail with reference to the drawings. FIG.  1 (A) is a partial perspective view of a terminal  10  which is an insert molding according to the present invention, FIG.  1 (B) is a partial sectional view of the same, and FIG.  1 (C) is a whole plan view of the same. 
     As shown in FIG.  1 (C), in the terminal  10 , a pair of bus bars  11  are insert-molded with resin having an insulating characteristic for connecting an electric equipment of a car. The bus bars  11  are made into suitable metal plate members having electrical conductivity, and disposed in parallel with each other along the axial direction of identical columnar circumferential surface in the state where the respective end portions of the bus bars  11  have been trued up. These bus bars  11  are projecting outside from a coating  12  in order to make the respective one end portions act as contact points respectively. 
     To manufacture such a terminal  10 , the bus bars  11  are held by a holding member  14  (see FIG.  1 (A)), and then molten resin is injected in the state where the holding member  14  is grasped between mold parts  15 A and  15 B (see FIG.  1 (B)). 
     The holding member  14  is formed from resin which is the same in material and color as the molten resin, so as to have a substantially H-shaped section having a pair of fixation portions  16  and  17 . The fixation portions  16  and  17  are formed into a substantially C-shape. The gap size of the C-portion is set so as to be a little smaller than the thickness of the bus bars  11 , so that when the bus bars  11  are pressed into the gap, the C-portion is elastically deformed to thereby grasp the bus bars  11  therein. 
     The thus configured holding member  14  is formed into a curved shape so that the holding member  14  can be brought into face contact with the arcuate inner wall surface of the mold part  15 A and the arcuate inner wall surface of the mold part  15 B. Accordingly, the holding member  14  is firmly grasped between the mold parts  15 A and  15 B. 
     In the thus configured terminal  10 , the bus bars  11  are firmly grasped by the fixation portions  16  and  17  of the holding member  14  at the time of insert molding. Therefore, the relative positions of the bus bars  11  and the holding member  14  are held surely, and this holding member  14  is grasped between the mold parts  15 A and  15 B. Accordingly, the relative positions of the bus bars  11  and the mold parts  15 A and  15 B are held surely. 
     Therefore, if molten resin is injected into the mold parts  15 A and  15 B in this state, it is possible to obtain the terminal  10  in which the bus bars  11  are coated with a thin film of the resin up to a desired thickness properly, and in which partially exposed portion cannot be formed. 
     As shown in FIG.  1 (C), the holding member  14  is integrated with a coating  12  as the molten resin is solidified, and there is no fear that the holding member  14  projects out from the surface of the thin film  12 . 
     The present invention is not limited to the above-mentioned embodiment, and it can be modified, reformed, etc., suitably. 
     For example, although the substantially H-shaped holding member which can be in face contact with the inner wall surface of the mold was shown by the way of example in the above-mentioned embodiment, the holding member according to the present invention includes such a form as shown in FIGS.  2 (A) to  2 (F). 
     That is, in a holding member  14 C shown in FIG.  2 (C), fixation portions  16 A and  17 A are formed as through holes into which bus bars which are conductor members can be inserted. If this holding member  14 C is adopted, it is further possible to obtain an effect that the bus bars can be fixed surely regardless of the injection speed of molten resin injected into the mold. 
     On the other hand, a peak portion  20  which can be in line contact with the inner wall surface (not-shown) of a mold is formed in a holding member  14 A shown in FIG.  2 (A), while a summit portion  21  which can be in point contact with the inner wall surface (not-shown) of a mold is formed in a holding member  14 B shown in FIG.  2 (B). If either of these holding members  14 A and  14 B is adopted, it is possible to obtain an effect that the area exposed in the surface of the coating can be reduced, so that the appearance of the insert molding can be improved. The fixation portions  16 A and  17 A are may be formed substantially into a C-shape like the embodiment shown in FIG.  1 (A). 
     Further, a holding member  14 D shown in FIG.  2 (D) is formed substantially in an S-shape in which apertures of fixation portions  16 B and  17 B are directed oppositely to each other, and nail portions  18  are provided at the outer edge portions of the apertures of the fixation portions  16 B and  17 B, respectively. 
     On the other hand, according to the present invention, relative positioning may be performed by making a convex portion provided in one of the conductor member and the holding member engage with the other. 
     Specifically, bus bars  11 A and the holding member  14  shown in FIG.  2 (E) are relatively positioned by making convex portions  22  integrally formed on the end surfaces of the bus bars  11 A engage with opening edge portions of the fixation portions  16  and  17 . 
     Further, bus bars  11 B and a holding member  14 E shown in FIG.  2 (F) are relatively positioned by making convex portions  23  integrally formed on the inner surfaces of fixation portions  16 C and  17 C engage with notches  24  formed in the end surfaces of the bus bars  11 B. 
     Moreover, materials, shapes, sizes, forms, numbers, locations, etc. of the mold, the conductor member, the resin, the insert molding, the holding member, the fixation portions, the convex portions, and so on, shown in the above embodiment by way of example are not limited and may be modified so long as the present invention can be attained even by the modification. 
     As has been described heretofore, according to the present invention, the conductor member is held by the holding member grasped by the mold. Accordingly, the holding member is integrated with the thin film, so that it is possible to eliminate any partially exposed portions formed in the conductor member. 
     Further, according to the present invention, it is possible to improve the appearance of the insert molding if the holding member is made from the same material as resin. 
     In addition, according to the present invention, the fixation portions of the holding member is formed substantially in a C-shape which can grasp the conductor member. Accordingly, it is possible to perform relative fixation between the conductor member and the holding member easily. 
     In addition, according to the present invention, it can be configured that the fixation portion is formed as the insertion holes to which the conductor members are inserted. Accordingly, the conductor members can be fixed surely regardless of the injection speed of molten resin injected into the mold. 
     Further, according to the present invention, it can be configured that the holding member is in line contact with the inner wall surface of the mold, or that the holding member is in point contact with the inner wall surface of the mold. Accordingly, it is possible to reduce the area of exposure of the holding member in the surface of coating, so that it is possible to improve the appearance of the insert molding. 
     In addition, according to the present invention, it can be configured that the convex portion provided in one of the conductor member and the holding member engaged with the other. Accordingly, it is possible to keep the relative positions of the conductor members and the holding member surely.