Electric device

Abstract

This electric device comprises: an electronic component having a terminal; a bus bar having a connection terminal that is connected to the terminal of the electric component; and a sealing member for sealing so as to cover at least a part of the bus bar. The sealing member has a through-hole in which the connection terminal is exposed on the inner peripheral surface. The connection terminal projects through the through-hole toward the opposite side to the side on which the electric component is disposed in the sealing member, and the tip of the connection terminal and the tip of the terminal of the electric component are welded to each other. The sealing member has a rising portion that forms a vertex at a position higher than the surface of a portion of the sealing member that seals the connection terminal on the side opposite to the side on which the electronic component is disposed, with the through-hole as a reference. The rising portion has a protrusion that is in contact with the terminal of the electric component at the edge of the through-hole.

Description

Electrical Equipment

[0001] The present invention relates to electrical equipment.

[0002] In electrical devices, it is important from the viewpoint of reliability to improve the positioning accuracy of the terminals while ensuring the strength of the installation area of ​​the terminals. For example, Patent Document 1 listed below discloses a structure in which a molded portion covering a bus bar has guide holes to more accurately position the terminal portions of the bus bar and the connection terminals of electronic components.

[0003] Japanese Patent Application Laid-Open No. 2017-183075

[0004] The capacitor terminal tips and the molded bus bars are connected by TIG (Tungsten Inert Gas) welding, but if the terminal tips are significantly misaligned, welding may not be possible.

[0005] The electrical equipment comprises an electronic component having a terminal, a bus bar having a connection terminal connected to the terminal, and a sealing member that seals and covers at least a portion of the bus bar, the sealing member having a through hole in which the connection terminal is exposed on its inner surface, the connection terminal protruding through the through hole toward the side of the sealing member opposite to the side on which the electronic component is placed, and the tip of the connection terminal being welded and connected to the tip of the terminal, the sealing member having a raised portion that forms an apex at a position higher than the surface of the part of the sealing member that seals the connection terminal, on the side opposite to the side on which the electronic component is placed, relative to the through hole, and the raised portion has a convex portion that contacts the terminal at the edge of the through hole.

[0006] According to the present invention, it is possible to provide an electric device that improves the accuracy of terminal positioning and further realizes stronger vibration resistance.

[0007] A developed view of a power conversion device. A cross-sectional view of a state in which a smoothing capacitor is connected to a DC side bus bar. A diagram showing the connection structure between terminals according to one embodiment of the present invention (enlarged view A of FIG. 2). A plan view of a DC bus bar. Enlarged view B of FIG. 4. A diagram showing the state when a smoothing capacitor terminal is inserted according to one embodiment of the present invention. A diagram showing the state when a smoothing capacitor terminal is inserted according to one embodiment of the present invention. A diagram showing the state after the smoothing capacitor terminal has been inserted according to one embodiment of the present invention. A diagram showing a method of welding the tips of terminals together according to one embodiment of the present invention.

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and some omissions and simplifications have been made as appropriate for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0009] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0010] (One embodiment and overall configuration) (FIG. 1) The housing 201 of the power conversion device 100 is made of metal, for example, an aluminum alloy, and is a box-like rectangular parallelepiped having a pair of short side walls and a long side wall. The housing 201 accommodates a power semiconductor circuit section 202, a smoothing capacitor 203, an EMC filter 204, an AC side bus bar 205, a DC side bus bar 206, etc.

[0011] The smoothing capacitor 203 is an electronic component that stabilizes the output by absorbing current changes caused by switching of the power semiconductor circuit unit 202. The EMC filter 204 is configured such that a module having a capacitor and a resistor that absorb noise is connected to an EMC filter bus bar.

[0012] The AC side bus bar 205 is an output side terminal of the power conversion device 100 and is connected to a motor (not shown). The DC side bus bar 206 connects the EMC filter 204 and the AC side bus bar 205, linking the input to the output. The DC side bus bar 206 is also electrically connected to the smoothing capacitor 203.

[0013] (FIGS. 2 and 3) DC side bus bar 206 is sealed by at least a portion thereof being covered with sealing member 303. Connection terminal 301 of DC side bus bar 206 that is not covered with sealing member 303 and terminal 302 of smoothing capacitor 203, which is an electronic component, are connected to each other by welding at their respective tips.

[0014] The sealing member 303 has a through hole 304. In the through hole 304, the connection terminal 301 of the DC side bus bar 206 is exposed on the inner peripheral surface, and the connection terminal 301 is provided rising upward in Fig. 3. The terminal 302 of the smoothing capacitor 203 protrudes through the through hole 304 from the side where the smoothing capacitor 203 is arranged toward the opposite side, and the tip of each terminal 302 is welded to the connection terminal 301 of the DC side bus bar 206.

[0015] The sealing member 303 has a rising portion 303c that rises from an edge 305 of the through hole 304 along the protruding direction of the terminal 302 of the smoothing capacitor 203, on the side opposite to the side on which the smoothing capacitor 203 is disposed, with the through hole 304 as a reference. The rising portion 303c has an apex 303a that is the apex of the rise, and a protruding portion 306 that is in contact with the terminal 302 of the smoothing capacitor 203. The protruding portion 306 is in contact with the terminal 302, thereby pressing the terminal 302 toward the connection terminal 301 of the DC side bus bar 206.

[0016] In this way, by having a structure that presses and corrects the tip of the capacitor terminal 302 against the connection terminal 301 on the molded bus bar side, it is possible to improve the accuracy of positioning of the terminal 302. Furthermore, by supporting the accuracy of positioning, it is possible to improve the strength of the terminal 302.

[0017] In addition, in order to increase the corrective force of the convex portion 306 on the terminal 302, the height of the rising portion 303c from the base position of the terminal 302 to the apex 303a is made higher than the surface 303b of the sealing member 303 that seals the connection terminal 301 located at the opposite position on the cross section.

[0018] Through hole 304 of sealing member 303 has terminal inlet portion 401 for inserting terminal 302 from the side where smoothing capacitor 203 is arranged, and terminal outlet portion 402 for bringing terminal 302 out to the outside on the side of through hole 304 opposite to the side where smoothing capacitor 203 is arranged. The inner diameter of terminal inlet portion 401 is larger than the inner diameter of through hole 304 at terminal outlet portion 402, and is formed such that the inner diameter of through hole 304 becomes smaller from terminal inlet portion 401 to terminal outlet portion 402.

[0019] Although not specifically shown, the through hole 304 is formed in a tapered shape, and therefore, the through hole 304 has a protrusion 306, a terminal entrance portion 401, and a terminal exit portion 402 formed at the front and back of FIG. 3 as well.

[0020] (FIGS. 4 and 5) The connection terminal 301 of the DC side bus bar 206 and the terminal 302 of the smoothing capacitor 203 are connected at their respective tips by welding. As shown in FIG. 5, the tip 601 of the connection terminal 301 of the DC side bus bar 206 and the tip 602 of the terminal 302 of the smoothing capacitor 203 are connected by welding. Note that the shape of the terminal 302 is not limited to a circular shape; for example, the portion that contacts the connection terminal 301 may be oval or flat. This increases the contact area between the tip 602 and the tip 601, making it easier to weld the tips together and improving weldability. Furthermore, this increases the contact area between the tips, shortening the effective current path and reducing inductance.

[0021] (FIGS. 6 to 8) Using FIG. 6 to FIG. 8, a process will be described in which terminal 302 is corrected toward connection terminal 301 when terminal 302 is inserted into through hole 304. In FIG. 6, terminal 302 of smoothing capacitor 203 is inserted into through hole 304 from the side where smoothing capacitor 203 is arranged. At this time, terminal 302 of smoothing capacitor 203 may be tilted toward the side opposite to the installation side of connection terminal 301 of DC side bus bar 206. However, through hole 304 has terminal entrance portion 401, and terminal entrance portion 401 is formed with a wide inner diameter, so that terminal 302 can be smoothly inserted into through hole 304 even when it is tilted.

[0022] 7, when terminal 302 of smoothing capacitor 203 is inserted into through-hole 304, it is inserted to terminal outlet 402 along guide surface 304a formed on the inner circumferential surface of sealing member 303 from terminal inlet 401 toward terminal outlet 402. As a result, even if terminal 302 is inserted into through-hole 304 at an angle in the direction opposite to connection terminal 301, it can be smoothly inserted into terminal outlet 402 along guide surface 304a.

[0023] The through-hole 304 has a tapered shape from the terminal entrance portion 401 to the terminal exit portion 402, and not only the guide surface 304a but also the guide surface 304b is formed on the opposite surface in cross section, so that even if the terminal 302 is tilted toward the connection terminal 301 before insertion, it can be smoothly inserted toward the terminal exit portion 402. In this way, the terminal 302 can be inserted smoothly through the through-hole 304 by being inserted along the guide surface 304a.

[0024] 8 , when terminal 302 reaches convex portion 306 of sealing member 303, convex portion 306 comes into contact with terminal 302, and terminal 302 comes into contact with, as if pressed against, connection terminal 301. Therefore, by inserting terminal 302 through through-hole 304 to the tip of connection terminal 301 so that the tip of terminal 302 is aligned, the portion of terminal 302 that passes through convex portion 306 can reliably maintain contact with connection terminal 301.

[0025] By doing this, not only are the connection terminals 301 and 302 ready to be welded together, but the convex portions 306 also improve the fixation of the terminals 302 by supporting the position adjustment of the capacitor terminals 302, thereby increasing their strength.

[0026] (FIG. 9) The connection terminal 301 and the terminal 302 are connected by, for example, earth chuck welding. Earth chuck welding is performed using a welding torch 1001 and a welding chuck 1002. In earth chuck welding, the connection terminal 301 of the DC side bus bar 206 and the terminal 302 of the smoothing capacitor 203 are clamped by the welding chuck 1002, and the tips of the terminals are aligned, and the tips of the terminals are welded together by the welding torch 1001.

[0027] When performing earth chuck welding, it is necessary to ensure a predetermined distance from the weld where the tips of the terminals are welded together. The required predetermined distance is, for example, 5 mm, which is the sum of the 2 mm thickness of the chuck jaws of the welding chuck 1002 and the 3 mm distance where the molten pool generated by the welded connection of the terminals does not come into contact with the chuck. In this way, by providing the apex 303 a of the rising portion 303 c below the weld at a predetermined distance, earth chuck welding can be performed reliably.

[0028] According to the embodiment of the present invention described above, the following advantageous effects are achieved.

[0029] (1) The electrical device comprises an electronic component (203) having a terminal (302), a bus bar (206) having a connection terminal (301) connected to the terminal (302), and a sealing member (303) that seals and covers at least a portion of the bus bar (206). The sealing member (303) has a through hole (304) through which the connection terminal (301) is exposed on its inner surface. The connection terminal (301) protrudes through the through hole (304) toward the side of the sealing member (303) opposite to the side on which the electronic component (203) is arranged, and the tip of the connection terminal (301) is welded and connected to the tip of the terminal (302). The sealing member (303) has, on the side opposite to the side on which the electronic component (203) is arranged, a raised portion (303c) that forms an apex (303a) at a position higher than the surface of the portion of the sealing member (303) that seals the connection terminal (301). The raised portion (303c) has a protrusion (306) that contacts the terminal (302) at the edge of the through hole (304). By doing so, reliability and earthquake resistance can be improved, and costs can be reduced.

[0030] (2) Through hole 304 has terminal entrance portion 401 for inserting terminal 302 from the side where electronic component 203 is arranged, and terminal exit portion 402 for bringing terminal 302 out of through hole 304 on the side opposite to the side where electronic component 203 is arranged, and is formed so that the inner diameter of through hole 304 decreases from terminal entrance portion 401 to terminal exit portion 402. This allows terminal 302 to be inserted into through hole 304 smoothly.

[0031] (3) The terminal 302 has a flat surface at the portion that comes into contact with the connection terminal 301. This configuration improves weldability and reduces inductance.

[0032] (4) The sealing member 303 has guide surfaces 304a and 304b extending from the terminal inlet 401 toward the terminal outlet 402, and the terminal 302 is inserted through the through hole 304 along the guide surfaces 304a and 304b. This configuration allows the terminal 302 to be pushed toward the connection terminal 301.

[0033] (5) The apex 303a is located below the welded portion where the terminal 302 and the connection terminal 301 are welded together. This allows earth chuck welding to be performed.

[0034] The present invention is not limited to the above-described embodiments, and various modifications and combinations of other configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to those having all of the configurations described in the above-described embodiments, and includes those in which some of the configurations are omitted.

[0035] REFERENCE SIGNS LIST 100 Power conversion device 201 Housing 202 Power semiconductor circuit section 203 Smoothing capacitor 204 EMC filter 205 AC side bus bar 206 DC side bus bar 301 Connection terminal 302 Capacitor terminal 303 Sealing member 303a Apex 303b Connection terminal side surface 303c Rising portion 304 Through hole 304a Guide surface (capacitor terminal side) 304b Guide surface (connection terminal side) 305 Edge 306 Convex portion 401 Terminal inlet portion 402 Terminal outlet portion 601 Tip (bus bar) 602 Tip (smoothing capacitor) 1001 Welding torch portion 1002 Welding chuck portion

Claims

1. An electrical device comprising: an electronic component having a terminal; a bus bar having a connection terminal connected to the terminal; and a sealing member sealing so as to cover at least a portion of the bus bar, wherein the sealing member has a through hole with the connection terminal exposed on its inner surface, the connection terminal protrudes through the through hole toward the side of the sealing member opposite to the side on which the electronic component is arranged, and a tip of the connection terminal is welded and connected to a tip of the terminal, the sealing member having a raised portion that forms an apex at a position higher than a surface of the portion of the sealing member that seals the connection terminal, on the side opposite to the side on which the electronic component is arranged, with respect to the through hole, and the raised portion has a convex portion that contacts the terminal at the edge of the through hole.

2. An electrical device as claimed in claim 1, wherein the through hole has a terminal entrance portion for inserting the terminal from the side on which the electronic component is arranged, and a terminal exit portion for bringing the terminal out to the outside of the through hole on the side opposite the side on which the electronic component is arranged, and the inner diameter of the through hole is formed so as to decrease from the terminal entrance portion to the terminal exit portion.

3. An electrical device according to claim 1, wherein the terminal has a flat surface that comes into contact with the connection terminal.

4. An electrical device according to claim 2, wherein the sealing member has a guide surface from the terminal inlet portion toward the terminal outlet portion, and the terminal is inserted through the through hole along the guide surface.

5. An electric device according to claim 1, wherein the apex is provided at a position lower than a welded portion where the terminal and the connection terminal are welded together.

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