Terminal block

Abstract

A waterproof structure of an externally exposed terminal block with a flat bus bar insert-molded thereon can save space and reduce costs, and has excellent layout properties. The terminal block is arranged so that the terminal block, which has improved layout properties by insert-molding a complex-shaped flat bus bar, is exposed to the outside of a housing. The bus bar that electrically connects the flat bus bar (4) of the terminal block to the inside of the housing is arranged in a cylindrical shape. An outer peripheral chamfer (16) is provided at the front end of the cylindrical bus bar (12), and a second sealing ring (17) is provided in a manner that contacts three surfaces: the flat bus bar, the outer peripheral chamfer of the cylindrical bus bar, and the terminal block molded resin.

Description

Technical Field

[0001] The present application relates to a waterproof structure of a terminal block of a vehicle-mounted power conversion device. Background Art

[0002] In the vehicle-mounted power conversion device, a terminal block is provided for connection with an external power source and a motor, and an external cable terminal is fastened to the terminal block with a bolt to achieve electrical connection.

[0003] In such a power conversion device, the following structure is proposed: a terminal block is arranged in a casing, and the casing is provided with a cable insertion hole and an operation hole for fastening the cable terminal bolt to the terminal block, and the operation hole is arranged in a manner perpendicular to the cable insertion hole. In addition, a gasket for ensuring waterproofness with the casing is provided on a bracket for fixing the cable to the casing, so that water, dust, etc. will not invade from the cable insertion hole and the operation hole, and the operation hole is sealed by a cover with a waterproof function (for example, refer to patent documents 1 and patent document 2).

[0004] On the other hand, a structure has been proposed in which the terminal block is exposed outside the housing and a gasket is provided between a flat bus bar electrically connecting the terminal block to the inside of the housing and the terminal block mold resin (for example, see Patent Document 3).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2004-327185

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 8-214492

[0009] Patent Document 3: Japanese Patent Application Laid-Open No. 2010-211933 Summary of the Invention

[0010] Technical problem to be solved by the invention

[0011] If the terminal block for electrically connecting to components outside the casing is set inside the casing as in the existing examples of patent documents 1 and 2, then a cable fixing bracket with a waterproof gasket and a cover with a waterproof gasket are required as additional components. In addition, conductive foreign matter such as thread debris generated by the installation and removal of the cable terminals during maintenance will invade the interior of the casing. In order to prevent short circuits between the terminals of the control circuit substrate and the power semiconductor, a dustproof structure needs to be provided between the terminal block and the casing, which will cause problems in saving space and reducing costs.

[0012] On the other hand, in the case of a structure in which the terminal block is exposed to the outside of the casing as in the existing example of patent document 3, in order to set a gasket between the flat bus bar and the molded resin of the terminal block, it is necessary to set a structure in which a flat bus bar with a simple shape such as a straight shape or an L-shape is inserted into the resin. In the case of a structure in which a flat bus bar with a complex shape is insert-molded in order to improve the layout, it is difficult to ensure the sealing between the flat bus bar and the molded resin, and there is a problem that the layout and waterproofness of the terminal block cannot be satisfied at the same time.

[0013] The present application is made to solve the above-mentioned problems, and its purpose is to obtain a waterproof structure of an externally exposed terminal block with a flat bus bar insert-molded thereon, which can save space and reduce costs and has excellent layout properties.

[0014] Technical solutions used to solve technical problems

[0015] The terminal block of the present application is characterized in that it is configured so that the terminal block with improved layout by insert molding of a complex-shaped flat bus bar is exposed to the outside of the casing, the bus bar that electrically connects the flat bus bar of the terminal block to the inside of the casing is configured to be cylindrical, an outer peripheral chamfered portion is provided at the front end portion of the cylindrical bus bar, and a sealing ring is provided in a manner that contacts three surfaces of the flat bus bar, the outer peripheral chamfered portion of the cylindrical bus bar, and the terminal block molded resin.

[0016] Effects of the Invention

[0017] The waterproof structure of the terminal block according to the present application is excellent in terms of space saving and cost reduction because the terminal block is provided outside the housing. In addition, since the terminal block is formed by insert molding a complex-shaped flat bus bar, it has excellent layout characteristics. Since the connecting portion between the terminal block and the interior of the housing is designed as a simple shape and a sealing portion is provided in this portion, it has excellent waterproof performance and salt water resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 These are external views of power conversion devices according to first to third embodiments of the present application.

[0019] Figure 2 These are external views of terminal blocks according to first to third embodiments of the present application.

[0020] Figure 3 It is an AA cross-sectional view of the terminal block according to the first to third embodiments of the present application.

[0021] Figure 4 It is a BB cross-sectional view of the terminal block according to the first to third embodiments of the present application.

[0022] Figure 5This is an enlarged view of the periphery of a seal ring provided on the terminal block according to the first to third embodiments of the present application.

[0023] Figure 6 It is a longitudinal sectional view of a seal ring according to a second embodiment of the present application.

[0024] Figure 7 It is a longitudinal sectional view of the seal ring according to the third embodiment of the present application.

[0025] Explanation of symbols

[0026] 1 housing

[0027] 2 terminal blocks

[0028] 3 connecting holes

[0029] 4First flat busbar

[0030] 5Electrical connection part

[0031] 6 First stud bolt

[0032] 7 First nut

[0033] 8 wiring harness terminals

[0034] 9 Second stud

[0035] 10 cylindrical resin holes

[0036] 11 electrical connection part

[0037] 12 cylindrical busbars

[0038] 13 Second flat bus bar

[0039] 14 Second nut

[0040] 15 first sealing ring

[0041] 16 Outer peripheral chamfer

[0042] 17 Second sealing ring

[0043] 18 Outer peripheral chamfer DETAILED DESCRIPTION

[0044] Hereinafter, the first embodiment of the present application will be described with reference to the accompanying drawings.

[0045] In addition, in each drawing, the same reference numerals represent the same or corresponding components.

[0046] Implementation Method 1

[0047] Figure 1 This is an external view of the housing 1 of the vehicle-mounted power conversion device according to the first to third embodiments of the present application. Figure 2This is an external view of the terminal block 2 for electrically connecting to components outside the housing.

[0048] according to Figure 1 as well as Figure 2 A terminal block 2 for electrically connecting to components outside the housing is located outside the housing 1. A communication hole 3 for electrically connecting the terminal block to the interior of the housing is provided on the wall of the housing 1, thereby achieving electrical connection. This eliminates the need for a cable fixing bracket with a waterproof gasket or a cover with a waterproof gasket required when the terminal block is located inside the housing, resulting in superior space savings and cost reductions.

[0049] Figure 3 and Figure 4 AA and BB cross-sectional views of the terminal block 2 are shown in FIG. Figure 3 as well as Figure 4 In the terminal block 2, the first flat bus bar 4 is insert-molded into the resin terminal block. This allows the bus bar to have a complex shape, which is excellent in terms of space saving and layout.

[0050] An electrical connection portion 5 electrically connected to the outside of the casing is provided on one side of the first flat bus bar 4. A first stud bolt 6 perpendicular to the plane of the first flat bus bar and facing the outside of the casing is pressed into the electrical connection portion 5 and is tightened with a first nut 7 to electrically connect to a wiring harness terminal 8 extending from a component outside the casing.

[0051] A second stud bolt 9, perpendicular to the plane of the first flat bus bar 4 and facing the interior of the housing, is pressed into the other side of the first flat bus bar 4. A cylindrical resin hole 10 is provided coaxially with the second stud bolt 9 and hollowed out into a cylindrical shape from the resin of the terminal block, exposing an electrical connection portion 11 electrically connected to the interior of the housing.

[0052] A cylindrical busbar 12 is inserted into the cylindrical resin hole 10. One side of the cylindrical busbar 12 contacts the electrical connection portion 11 of the first flat busbar, and the other side passes through the connecting hole 3 and contacts the second flat busbar 13 provided inside the casing. The second stud bolt 9 passes through the holes provided in the cylindrical busbar 12 and the second flat busbar 13 and is tightened with the second nut 14. Thus, the first flat busbar 4 and the second flat busbar 13 are electrically connected through the cylindrical busbar 12.

[0053] Figure 5 FIG shows an enlarged view of the periphery of the electrical connection portion 11 of the first flat bus bar that is electrically connected to the interior of the housing. Figure 5A first sealing ring 15 is provided on the contact surface of the housing around the connecting hole 3 with the terminal block to prevent water and dust from entering the housing. In the first embodiment, the first sealing ring 15 is configured as a surface seal, but it can also be a shaft seal that abuts the connecting hole 3.

[0054] The surface of cylindrical busbar 12 that contacts the first flat busbar is provided with an outer peripheral chamfer 16. A second seal ring 17 is provided so as to contact three surfaces: outer peripheral chamfer 16, the inner diameter of cylindrical resin hole 10, and electrical connection portion 11 of the first flat busbar, which is electrically connected to the interior of the housing. This single seal ring prevents water from entering the interface between the resin of the terminal block and the busbar from entering both the interface between cylindrical busbar 12 and electrical connection portion 11 and the gap between cylindrical busbar 12 and cylindrical resin hole 10. Since the seal ring installation area saves space, the contact area between cylindrical busbar 12 and electrical connection portion 11 can be maximized, resulting in excellent low-current resistance and cost reduction.

[0055] The outermost diameter of the press-fit portion of the second stud 9 is φd, the inner diameter of the cylindrical busbar is φD1, and the outermost diameter of the cylindrical busbar where it contacts the first flat busbar is φD2. In this case, the relationship D1 < d < D2 is established. As a result, the axial force generated by tightening the second nut 14 is applied to the press-fit portion of the second stud 9. Therefore, even if the first flat busbar 4, cylindrical busbar 12, and second stud 9 contract or expand due to thermal cycling, a high surface pressure is maintained at the interface between the first flat busbar 4 and the second stud 9, effectively preventing water intrusion.

[0056] Implementation Method 2

[0057] Figure 6 This is a longitudinal sectional view of the second sealing ring 17 of the second embodiment of the present application. Figure 6 The cross section is hexagonal, making surface contact with the electrical connection portion 11 and linear contact with the inner diameter of the cylindrical resin hole 10 and the outer circumferential chamfered portion 16. Therefore, even if the wire diameter of the second seal ring 17 is set small to ensure the contact area between the first flat bus bar 4 and the cylindrical bus bar 12, suppress the on-resistance, and achieve space saving, if the second seal ring 17 is inserted into the cylindrical resin hole 10 during assembly using a cylindrical insertion jig having an outer circumferential chamfered portion at the front end, similar to the cylindrical bus bar 12, the second seal ring 17 is inserted while being accommodated in the groove formed by the outer circumferential chamfered portion of the insertion jig and the cylindrical resin hole 10. Therefore, the second seal ring 17 can be assembled to the specified position without being twisted.

[0058] In addition, at the intersection of the first flat bus bar formed by insert molding and the cylindrical resin hole 10, slight resin burrs will be generated on the inner diameter side. However, since the second sealing ring 17 is provided with an outer peripheral chamfered portion 18 in a shape that contacts the inner diameter line of the cylindrical resin hole 10, the second sealing ring 17 can stably contact and seal the electrical connection portion 11 without riding on the resin burrs.

[0059] Implementation Method 3

[0060] Figure 7 This is a longitudinal sectional view of the second sealing ring 17 of the third embodiment of the present application. Figure 7 The cross section is hexagonal and plane-symmetrical. This prevents vertical misassembly during assembly of the second seal ring 17, resulting in excellent quality and cost reduction since no equipment or steps are required to prevent misassembly.

[0061] Furthermore, in the cross section, the axial direction is wider than the radial direction, thereby enabling line contact between the second seal ring 17 and the chamfered portion 16 of the outer peripheral surface of the cylindrical bus bar.

[0062] This application describes various exemplary embodiments, but various features, methods, and functions described in one or more embodiments are not limited to application to specific embodiments and can be applied to the embodiments alone or in various combinations.

[0063] Therefore, numerous modifications not shown are contemplated within the technical scope disclosed in this application. For example, these include modifying, adding, or omitting at least one component, and also include extracting at least one component and combining it with components from other embodiments.

Claims

1. A terminal block, which is a terminal block of a vehicle-mounted power conversion device, and is used to electrically connect to components outside the housing, characterized in that: The terminal block is configured to be exposed to the outside of the housing, A connecting hole is provided on the wall surface of the housing, and the connecting hole is used to electrically connect the terminal block with the interior of the housing. In the terminal block, the first flat bus bar is insert-molded in the resin terminal block. An electrical connection portion for external electrical connection is provided on one side of the first flat bus bar, and a stud bolt perpendicular to the plane of the first flat bus bar and facing the interior of the housing is pressed into the other side of the first flat bus bar. The electrical connection portion electrically connected to the inside of the housing is exposed by providing a cylindrical resin hole, the cylindrical resin hole being coaxial with the stud bolt and formed by hollowing out the resin of the terminal block into a cylindrical shape. A cylindrical bus bar is inserted into the cylindrical resin hole, one side of the cylindrical bus bar contacts the first flat bus bar, and the other side of the cylindrical bus bar passes through the communication hole and contacts the second flat bus bar provided inside the housing. The stud bolts pass through holes provided in the cylindrical bus bar and the second flat bus bar and are fastened by nuts, thereby electrically connecting the first flat bus bar and the second flat bus bar through the cylindrical bus bar. A first sealing ring is provided on the surface of the housing around the communicating hole where the housing contacts the terminal block. The cylindrical bus bar is provided with an outer peripheral chamfered portion on the surface in contact with the first flat bus bar. A second seal ring is provided in contact with three surfaces: the outer peripheral chamfer, the inner diameter of the cylindrical resin hole, and the first flat bus bar. The outermost diameter of the press-fit portion of the stud bolt is φd, the inner diameter of the cylindrical bus bar is φD1, and the outermost diameter of the cylindrical bus bar in contact with the first flat bus bar is φD2. In this case, the relationship D1<d<D2 is formed. The second seal ring is in surface contact with the first flat bus bar, and is in line contact with the inner diameter of the cylindrical resin hole and the chamfered portion of the outer peripheral surface of the cylindrical bus bar.

2. The terminal block according to claim 1, wherein: The second sealing ring has a hexagonal cross section and a plane-symmetrical shape.

Images