Fuse unit

Abstract

To provide a fuse unit capable of improving a rotation regulating function relative to fastening of a nut.SOLUTION: A fuse unit includes: a bus bar 3 having a terminal connection unit 9 to which a terminal is electrically connected and a fusible body that is fused by an overcurrent; and a support member 5 made of a resin material for supporting the bus bar 3 and a screw member that is arranged in the terminal connection unit 9 and electrically connects the terminal and the terminal connection unit 9 by clamping them by fastening a nut. The terminal connection unit 9 is provided with a hole unit 31 opened in a side of a support member 5, and the support member 5 is provided with a filling unit 33 to be filled in the hole unit 31 when the support member 5 is molded.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a fuse unit. [Background technology]

[0002] Conventionally, a fuse unit includes a bus bar having a terminal connection portion to which a terminal is electrically connected and a fusible element that melts due to an overcurrent. Also known is a fuse unit including a terminal block as a support member made of a resin material that supports the bus bar and a screw member that is disposed on the terminal connection portion and sandwiches and electrically connects the terminal and the terminal connection portion by fastening a nut (see Patent Document 1). In this fuse unit, the terminal block is provided with a protrusion that protrudes toward the terminal connection portion. When the nut is fastened to the screw member, the tip of the protrusion abuts against the terminal connection portion, suppressing rotation of the terminal connection portion due to fastening of the nut. In such a fuse unit, by abutting the protrusion against the terminal connection portion, a larger frictional force can be obtained than by abutting a flat portion against the terminal connection portion, and rotation of the terminal connection portion can be suppressed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-220415 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in the fuse unit of Patent Document 1 mentioned above, rotation of the terminal connection portion caused by fastening the nut is suppressed by the frictional force between the protrusion and the terminal connection portion, but the rotation restriction function of the frictional force may be insufficient.

[0005] The present invention has been made in view of the problems inherent in the conventional technology, and an object of the present invention is to provide a fuse unit that can improve the rotation restriction function for tightening a nut. [Means for solving the problem]

[0006] The fuse unit of this embodiment comprises a bus bar having a terminal connection portion to which a terminal is electrically connected and a fusible element that melts due to an overcurrent, and a support member made of a resin material that supports the bus bar and a screw member that is disposed on the terminal connection portion and clamps and electrically connects the terminal and the terminal connection portion by tightening a nut, the terminal connection portion being provided with a hole portion that is open on the support member side, and the support member being provided with a filling portion that is filled inside the hole portion when the support member is molded. Effect of the Invention

[0007] According to the present invention, it is possible to provide a fuse unit that can improve the function of restricting rotation when the nut is fastened. [Brief description of the drawings]

[0008] [Figure 1] 2 is a perspective view of the fuse unit according to the embodiment with terminals attached thereto; FIG. [Diagram 2] 4 is a perspective view showing a state where a terminal is attached to the fuse unit according to the embodiment; FIG. [Diagram 3] FIG. 2 is a top view of the fuse unit according to the embodiment. [Figure 4] FIG. 4 is an enlarged view of a main part of FIG. [Diagram 5] FIG. 4 is a cross-sectional view of FIG. 3 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The fuse unit according to the present embodiment will be described in detail below with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for the convenience of explanation and may differ from the actual ratios.

[0010] 1, the fuse unit 1 according to this embodiment is disposed, for example, between a battery (not shown) mounted on a vehicle and an electrical component (not shown). The battery and the electrical component are electrically connected via the fuse unit 1. When an overcurrent flows, the fuse unit 1 cuts off the supply of power from the battery to the electrical component to protect the electrical component.

[0011] Although not shown, the battery is formed, for example, in a rectangular parallelepiped shape, and is provided with battery posts protruding outward from the outer surface. Battery terminals are electrically connected to the battery posts. The fuse unit 1 is electrically connected to the battery terminals.

[0012] As shown in FIGS. 1 to 5, the fuse unit 1 includes a bus bar 3 and a support member 5. The bus bar 3 and the support member 5 are electrically connected to each other.

[0013] The bus bar 3 is made of a conductive material, and includes a battery connection portion 7 , a terminal connection portion 9 , and a fusible element 11 .

[0014] The battery connection portion 7 has a hole formed penetrating the busbar 3. A stud bolt (not shown) provided on the battery terminal is inserted into the hole in the battery connection portion 7. The battery connection portion 7 electrically connects the busbar 3 to the battery via the battery terminal by fastening a nut (not shown) to the stud bolt of the battery terminal.

[0015] A plurality of terminal connection parts 9 (two in this example) are provided, each having a hole formed penetrating the busbar 3. A screw member 13 made of a stud bolt is inserted through the hole and disposed in the terminal connection part 9. In the terminal connection part 9, for example, a terminal 17 provided at an end part of an electric wire 15 electrically connected to an electric component is inserted through the screw member 13. The terminal 17 inserted through the screw member 13 is sandwiched between the nut 19 and the terminal connection part 9 by fastening the nut 19 to the screw member 13, and is electrically connected to the busbar 3. By electrically connecting the terminal 17 to the terminal connection part 9, the battery and the electric component are electrically connected via the busbar 3. A washer is disposed between the nut 19 and the terminal 17.

[0016] The fusible element 11 is provided at multiple locations (two locations here) on the busbar 3 between the battery connection portion 7 and the multiple terminal connection portions 9. The fusible element 11 is fixed to the busbar 3 by crimping a pair of crimping pieces. The fusible element 11 melts when an overcurrent is input to the busbar 3 during power supply from the battery to the electrical components. When the fusible element 11 melts, the power supply from the battery to the electrical components is cut off, thereby protecting the electrical components.

[0017] The support member 5 is made of a resin material, and is insert-molded using a molding die (not shown) so as to cover the periphery of the bus bar 3. The support member 5 includes a battery support portion 21, a terminal support portion 23, and a fusible element support portion 25.

[0018] The battery support part 21 is provided for the battery connection part 7 of the busbar 3. The battery support part 21 is molded integrally with the busbar 3 so as to expose both surfaces near the periphery of the hole of the battery connection part 7 to the outside and to cover the outer edge of the battery connection part 7.

[0019] Terminal support portion 23 is provided in a plurality of locations (two locations in this example) so as to respectively correspond to a plurality of terminal connection portions 9 of bus bar 3. Terminal support portion 23 is molded integrally with bus bar 3 and screw member 13 so as to expose one side near the periphery of the hole of terminal connection portion 9 to the outside and cover the outer edge of terminal connection portion 9 and the base end side of screw member 13.

[0020] The fusible element support portion 25 is provided at a plurality of locations (two locations in this example) so as to respectively correspond to the plurality of fusible elements 11 of the bus bar 3. The fusible element support portion 25 is molded integrally with the bus bar 3 located near the fusible element 11 so as to expose the fusible element 11. The opening of the fusible element support portion 25 is closed by attaching a cover (not shown).

[0021] A plurality of fins 27 are provided on the outer surface of the support member 5 in a portion in which the bus bar 3 is disposed. The fins 27 come into contact with the outside air to dissipate heat generated in the bus bar 3 and cool the bus bar 3.

[0022] A rotation restricting portion 29 is provided between the terminal support portion 23 of the support member 5 and the terminal connection portion 9 of the busbar 3, for restricting rotation of the terminal connection portion 9 when the nut 19 is fastened to the screw member 13. In the present embodiment, the rotation restricting portion 29 is provided only on one of the terminal connection portions 9, but the rotation restricting portion 29 may be provided on the other terminal connection portion 9. The rotation restricting portion 29 includes a hole portion 31 provided in the terminal connection portion 9 and a filling portion 33 provided in the support member 5.

[0023] Hole 31 is disposed away from screw member 13 of terminal connection portion 9, and is formed in a circular shape penetrating busbar 3 in the thickness direction. Note that hole 31 may be closed on the side opposite support member 5 as long as the side facing support member 5 is open. Hole 31 is formed to have a tapered surface 35 whose diameter increases in the direction away from support member 5 so that the opening on the side facing opposite support member 5 has a larger diameter than the opening on the side facing support member 5. Therefore, the volume of the inside of hole 31 increases in the direction away from support member 5.

[0024] The filling portion 33 is disposed at a position corresponding to the hole 31 of the terminal support portion 23, and is formed by filling the hole 31 with molten resin when the support member 5 is molded for the busbar 3. The filling portion 33 receives an external force in the rotation direction applied to the terminal connection portion 9 by fastening the nut 19 to the screw member 13. At this time, since the filling portion 33 is filled in the hole 31, it is in close contact with the entire inner surface of the hole 31 and can receive the external force over a wide range. Therefore, the rotation of the terminal connection portion 9 by fastening the nut 19 can be stably restricted, and the rotation restriction function for fastening the nut 19 can be improved. Since the hole 31 of the filling portion 33 is expanded in the direction away from the support member 5, the surface area in contact with the inner surface of the hole 31 increases in the direction away from the support member 5. Therefore, when an external force is applied to the terminal connection portion 9 in the direction away from the support member 5, the external force can be received over a wide range, and the terminal connection portion 9 can be stably held on the support member 5.

[0025] Here, for example, suppose that a protrusion is provided that protrudes outward from the outer edge of the terminal connection portion 9, and the support member 5 is formed so that the protrusion is located inside, thereby restricting the rotation of the terminal connection portion 9 and restricting it from floating up from the support member 5. In this structure, since the protrusion protrudes from the bus bar 3, the bus bar 3 becomes larger, the weight of the bus bar 3 increases, and the cost of the bus bar 3 also increases. Furthermore, since the protrusion is located inside the support member 5, the portion where the protrusion is located protrudes outward and becomes larger. In contrast, the hole portion 31 is provided on the surface of the terminal connection portion 9 facing the support member 5, so there is no portion that protrudes from the outer edge of the bus bar 3, and the weight and cost of the bus bar 3 can be reduced. Furthermore, since the filling portion 33 of the support member 5 is filled in the hole portion 31, the support member 5 does not become larger.

[0026] Such a fuse unit 1 includes a bus bar 3 having a terminal connection portion 9 to which a terminal 17 is electrically connected and a fusible element 11 that melts due to an overcurrent. Also includes a support member 5 made of a resin material that supports the bus bar 3 and a screw member 13 that is disposed on the terminal connection portion 9 and clamps and electrically connects the terminal 17 and the terminal connection portion 9 by fastening a nut 19. Also, the terminal connection portion 9 is provided with a hole portion 31 that is open on the support member 5 side. And the support member 5 is provided with a filling portion 33 that is filled inside the hole portion 31 when the support member 5 is molded.

[0027] Since the filling portion 33 is filled in the hole 31, it is in close contact with the entire inner surface of the hole 31, and can withstand a wide range of the external force in the rotational direction applied to the terminal connection portion 9 by fastening the nut 19 to the screw member 13. Therefore, the rotation of the terminal connection portion 9 caused by fastening the nut 19 can be stably restricted.

[0028] Therefore, in such a fuse unit 1, the function of restricting rotation of the fastening of the nut 19 can be improved.

[0029] Moreover, the hole 31 is formed so as to increase in diameter in a direction away from the support member 5 .

[0030] Filling portion 33 filled in hole 31 has a surface area that contacts the inner surface of hole 31 increasing in the direction away from support member 5. Therefore, when an external force is applied to terminal connection portion 9 in the direction away from support member 5, the external force can be received over a wide range, and terminal connection portion 9 can be stably held on support member 5.

[0031] Although the present embodiment has been described above, the present embodiment is not limited to this, and various modifications are possible within the scope of the gist of the present embodiment.

[0032] For example, one hole and one filling portion are provided between the terminal connection portion (bus bar) and the support member, but two or more holes and filling portions may be provided between the terminal connection portion (bus bar) and the support member. When a plurality of holes and filling portions are provided, they can be arranged at equal intervals in the circumferential direction around the screw member, so that external forces in the rotational direction can be received evenly in the rotational direction.

[0033] Further, although two terminal connection portions are provided on the bus bar, the present invention is not limited to this, and one terminal connection portion, or three or more terminal connection portions may be provided on the bus bar. [Explanation of symbols]

[0034] 1 Fuse unit 3 Bus bar 5 Supporting member 9 Terminal connection 11 Soluble 13 Screw material 17 Terminal 19 Nut 31 Hole 33 Filling section

Claims

1. a bus bar having a terminal connection portion to which a terminal is electrically connected and a fusible element that melts due to an overcurrent; a support member made of a resin material that supports the bus bar and a screw member that is disposed on the terminal connection portion and that sandwiches and electrically connects the terminal and the terminal connection portion by fastening a nut; Equipped with The terminal connection portion is provided with a hole portion that is open on the support member side, The support member is provided with a filling portion that is filled into the hole when the support member is molded.

2. The fuse unit according to claim 1 , wherein the hole is formed so as to increase in diameter in a direction away from the support member.

Images