JP2020077532A - Bolt and bus bar fixing method and fixing structure - Google Patents

Abstract

To provide a bolt and bus bar fixing method which suppresses leakage of a resin while using a standard bolt of which the cost is lower than that of a caulking bolt, and provide a fixing structure.SOLUTION: An axial part 521 of a bolt 52 having the axial part 521 and a head part 522 is inserted into a bolt insertion hole 511 provided to a bus bar 51, and a nut 80 is screwed into the axial part 521 of the bolt 52 to nip the bus bar 51 in a space of the head part 521 of the bolt 52. The bus bar 51 and the bolt 52 are set to a metal molding 70, a resin is cast into the metal molding 70 so as to cover a whole area of the head part 522 to detach the nut 80 from the bolt 52.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a bolt / busbar fixing method for fixing a bolt and a busbar with a resin and a bolt / busbar fixing structure in which the bolt and the busbar are fixed with a resin.

  There is known an electric component having a bolt / busbar fixing structure in which a bolt is inserted into a bolt insertion hole provided in a metal plate called a busbar and the bolt and the busbar are fixed with resin. Then, the bolt is inserted into another bus bar having a hole or a round terminal and fixed with a nut. In this way, electrical wiring is realized. If the resin leaks to the surface of the bus bar that constitutes this bolt / bus bar fixing structure on the side to which another bus bar, round terminal, or the like is fixed, contact failure may occur. Therefore, it is important to prevent this leakage when manufacturing an electrical component having this bolt / busbar fixing structure.

  Patent Document 1 discloses a bolt / busbar fixing structure using caulking bolts. In this patent document 1, the above leak is prevented by making the caulking bolt bite into the bus bar.

JP, 2011-28969, A

  The use of caulking bolts in the production of the above bolt / busbar fixing structure can strongly suppress the above leakage. However, the caulking bolt has a problem that it is more expensive than a standard bolt having no caulking function.

  In view of the above circumstances, an object of the present invention is to provide a bolt / busbar fixing method and a fixing structure which use a low-cost bolt as compared with a caulking bolt and which suppresses the above leakage.

The bolt and bus bar fixing method of the present invention that achieves the above object,
In the bolt insertion hole provided in the bus bar, insert the shaft portion of the bolt having the shaft portion and the head portion,
Screw the nut onto the shaft of the bolt and insert the bus bar between the head of the bolt and
Set the bus bar and bolt in the mold,
Pour the resin into the mold to cover the entire head,
Characterized by removing the nut from the bolt.

  According to the bolt / bus bar fixing method of the present invention, the nut is screwed onto the shaft portion of the bolt to sandwich the bus bar between the head of the bolt and the nut, and then the resin is poured into the mold. As a result, it is possible to prevent the resin from leaking to the shaft portion side of the bolt and prevent the resin from entering between the bolt and the bus bar.

  Here, in the bolt / busbar fixing method of the present invention, the nut is preferably a nut including a base portion and a flange having an outer diameter larger than the outer diameter of the base portion.

  The so-called standard bolts and standard flanged nuts have insufficient accuracy in the outer diameter of the flange and the dimensions of the screw holes of the nuts, and therefore, the accuracy in fixing the bolts to the bus bar tends to be insufficient. A nut with a flange as a jig can be manufactured with sufficient accuracy. Then, by using a high precision nut as the jig, the position of the bolt can be adjusted with high precision. In this case, the manufacturing cost of the nut as a jig is high, but the nut can be removed and reused any number of times, which does not impose a large cost burden.

Further, the bolt / busbar fixing structure of the present invention,
A bus bar with a bolt insertion hole,
A bolt having a shaft portion and a head portion having a flat surface facing the shaft portion, the shaft portion being inserted through the bolt insertion hole, and the flat surface of the head portion being pressed around the bolt insertion hole of the bus bar. When,
A resin made of a uniform material that covers the entire head is provided.

  According to the present invention, a bolt / busbar fixing structure using the so-called standard bolt having the above-mentioned flat surface and having no crimping function is realized.

  According to the present invention described above, a bolt / busbar fixing method and fixing structure can be realized in which the above-mentioned leakage is suppressed while using a low-cost bolt as compared with a caulking bolt.

FIG. 6 is a front view showing a connector in which a bolt and a bus bar are overmolded with resin. It is sectional drawing which follows the arrow XX shown in FIG. It is a schematic diagram showing one embodiment of the bolt and bus bar fixing method of the present invention.

  Hereinafter, embodiments of the present invention will be described.

  First, an outline of an example of an electrical component having a bolt / busbar fixing structure as one embodiment of the present invention will be described.

  FIG. 1 is a front view showing a connector in which a bolt and a bus bar are overmolded with resin.

  The connector 50 is a connector that electrically connects an internal circuit and an external circuit of the aluminum case 10 such as an inverter. The connector 50 is a connector for large current transmission, which includes a bus bar 51 and a bolt 52.

  FIG. 2 is a cross-sectional view taken along the arrow XX shown in FIG.

  FIG. 2 shows a bolt / busbar fixing structure provided on the connector 50.

  The connector 50 includes a bus bar 51 and a bolt 52 as shown in FIG.

  The bus bar 51 extends from the inside of the inverter case 10 and is exposed around the bolt 52 on the surface of the connector 50. The bus bar 51 is provided with a bolt insertion hole 511. The bolt 52 has a shaft portion 521 and a head portion 522. The shaft portion 521 is inserted into the bolt insertion hole 511, and the flat surface 525 of the flange 523 of the head portion 522 is in a portion around the bolt insertion hole 511 of the bus bar 51. Are in contact. The head 522 of the bolt 52 and the bus bar 51 on the head 522 side are fixed with resin 53. As shown by the alternate long and short dash line in FIG. 2, the shaft portion 521 of the bolt 52 is inserted into the hole of the external bus bar 61, and the two bus bars 51, 61 are fixed in contact with each other by the nut 62. As a result, a current path connecting inside and outside the case 10 is formed.

  FIG. 3 is a schematic view showing one embodiment of the bolt / busbar fixing method of the present invention.

  Bus bar 51 and bolt 52 shown in FIG. 3 are the same as bus bar 51 and bolt 52 shown in FIG. 2, respectively.

  Here, in pressing the flat surface 525 of the flange 523 of the bolt 52 against the bus bar 51, the nut 80 with the flange 82 is used. As an example, the outer shape of the base 81 of the nut 80 is hexagonal, and the outer shape of the flange 82 is circular. The outer diameter of the flange 82 is larger than the outer diameter of the base 81. The nut 80 used here is a nut manufactured as a highly accurate jig having a dimensional accuracy of ± 1/100 mm, for example.

  The nut 80 is screwed into the bolt 52. Then, the portion of the bus bar 51 around the bolt insertion hole 511 is sandwiched between the flange 82 of the nut 80 and the flange 523 of the bolt 52 and tightened. By doing so, the flange 523 of the bolt 52 is strongly pressed against the bus bar 51 (for example, with a force of about 4000 N).

  As a result, the path of the arrow R shown in FIG. 3 is closed, and even if the resin is poured into the mold 70, the resin is strongly suppressed from leaking to the shaft portion 521 side of the bolt 52.

  Further, the nut 80 is a jig manufactured with high precision. By utilizing the outer diameter of the flange 82 of the nut 80, the bolt 52 is positioned with high accuracy in the mold.

  Further, by using this nut 80, it is not necessary to press the recess 524 of the head 522 with a movable part (not shown) of the mold 70, and the movable part can be eliminated from the mold 70. As a result, the head 522 of the bolt 52 is covered with a uniform resin as shown in FIG. 2, and post-treatment such as injection of a potting agent is unnecessary. Further, the life of the mold 70 can be extended.

  After the resin poured into the mold 70 is solidified, the bus bar 51 and the like are taken out of the mold 70, and the nuts 80 are removed from the bolts 52. This nut is reused repeatedly.

  Although the nut 80 has been described as a jig manufactured with high precision here, if it is not necessary to increase the positional accuracy of the bolt 52, it is not necessary to manufacture the nut 80 as a jig. Commercially available flanged nuts can be used.

10 Inverter Case 50 Connector 51 Bus Bar 511 Bolt Insertion Hole 52 Bolt 521 Shaft 522 Head 523 Flange 524 Dimple 525 Flat Surface 53 Resin 61 External Bus Bar 62 Nut 70 Mold 80 Nut 81 Nut Base 82 Nut Flange

Claims (3)

In the bolt insertion hole provided in the bus bar, insert the shaft portion of the bolt having the shaft portion and the head portion,
A nut is screwed onto the shaft of the bolt, and a bus bar is sandwiched between the bolt and the head of the bolt.
Set the bus bar and the bolt in the mold,
Pour resin into the mold to cover the entire head,
A bolt / busbar fixing method, characterized in that the nut is removed from the bolt.   The bolt / bus bar fixing method according to claim 1, wherein the nut is a nut including a base portion and a flange having an outer diameter larger than an outer diameter of the base portion. A bus bar with a bolt insertion hole,
A shaft portion and a head portion having a flat surface facing the shaft portion, the shaft portion is inserted into the bolt insertion hole, and the flat surface is pressed around the bolt insertion hole of the bus bar. Bolts,
A bolt / busbar fixing structure comprising: a resin made of a uniform material that covers the entire head portion.

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