JP7395329B2 - power converter - Google Patents

Description

The present invention relates to a power conversion device.

In the design of in-vehicle electrical equipment, with the demand for higher output and smaller size of power converters, it is required to suppress radiated noise and external noise in order to improve the reliability of in-vehicle components. Therefore, a technique has been proposed in which an insulating support member or shielding plate is provided to support the circuit board.

As background art for the present invention, the following Patent Document 1 is known. Patent Document 1 describes a patented technology that enables miniaturization of a power conversion device while ensuring noise resistance and insulation between a power semiconductor module and a drive circuit board.

International Publication No. 2018/131336

In noise countermeasures, it is a well-known fact that the main body case ground is generally connected to the ground of the electric circuit board through a short and thick metal body. The challenge here was to further strengthen noise resistance.

A power conversion device according to the present invention includes a circuit board having a ground wiring pattern, a conductive casing housing the circuit board, and a grounding bus bar electrically connecting the ground wiring pattern and the casing. A power conversion device comprising: the grounding bus bar being arranged on a first surface of the circuit board; and the grounding bus bar extending in a plane direction parallel to the first surface; The first area has a first area that is arranged at a predetermined distance from the first surface, and the first area includes a first terminal to be inserted into a through hole provided in the circuit board, and a first terminal that is inserted into a through hole provided in the circuit board. A second terminal that contacts the first surface of the circuit board is provided, and the first terminal and the second terminal are electrically connected to the ground wiring pattern, respectively.

According to the present invention, the noise resistance of the power conversion device is enhanced.

1 is a diagram of the overall configuration of a power conversion device according to the present invention. 1 is a diagram of a part of a power conversion device according to the present invention. 1 is a diagram of a part of a power conversion device according to a first embodiment of the present invention. FIG. FIG. 3 is a diagram of a bus bar and a circuit board according to a first embodiment of the present invention. FIG. 7 is a diagram of a connector, a bus bar, and a circuit board according to a second embodiment of the present invention. FIG. 7 is a diagram of a connector, a bus bar, and a circuit board according to a third embodiment of the present invention. It is a figure of a main body case, a bus bar, and a circuit board concerning a 4th embodiment of the present invention.

(Structure of power conversion device and first embodiment)
FIG. 1 is an exploded perspective view showing the overall configuration of a power conversion device according to the present invention.

The power converter includes an inverter main body, a main body case 15, a DCDC board, a circuit board 3, and a board base. Of these, the present invention mainly relates to the circuit board 3 and the main body case 15.

FIG. 2 is a diagram of a part of the power conversion device related to the circuit board 3 and the main body case 15.

The circuit board 3 is connected to the bus bar 1, the connector 4, and the main body case 15. The main body case 15 has the ground impedance of the vehicle in which the power conversion device is mounted, and the bus bar 1 is screwed to the main body case 15, so that it is electrically connected to the main body case 15 through metal washers and bushes (not shown). Connected. Further, the bus bar 1 is provided with a terminal in order to be electrically connected to the ground of the circuit board 3 (not shown).

In the conventional invention, the electrical connection with the circuit board 3 was only made through the first terminal 7 of the bus bar 1, but the point of the present invention is that the second terminal 8 is also electrically connected to the circuit board 3. The point is that it is.

FIG. 3 is a diagram showing a partial configuration of a power conversion device according to the first embodiment of the present invention.

The power conversion device of the present invention includes a bus bar 1, a circuit board 3, and a connector 4.

The bus bar 1 is a grounding bus bar that electrically connects a main body case 15, which is a conductive casing that houses the circuit board 3, to a ground wiring pattern (not shown) passing through the inside of the circuit board 3. Note that a part of the ground wiring pattern (not shown) of the circuit board 3 is exposed on the surface of the circuit board 3 and forms the GND copper foil section 2. The GND copper foil section 2 is electrically connected to the second terminal 8 of the bus bar 1.

The first screw portion 5 and the second screw portion 6 are holes for screwing and fixing the bus bar 1, the circuit board 3, and the main body case 15. Further, the connector 4 is installed on the same surface of the circuit board 3 as the surface on which the bus bar 1 is installed.

FIG. 4 is a diagram with the connector 4 removed from a part of the configuration of the power conversion device in FIG. 3, and is a diagram showing the overall structure of the bus bar 1.

The bus bar 1 has a first terminal 7, a second terminal 8, a bent portion 9, a first region 10, a second region 11, and a pin hole 12. The first terminal 7 and the second terminal 8 are provided in the first region 10.

The bus bar 1 is arranged on one side of the circuit board 3 and is parallel to the circuit board 3. In order to provide a predetermined amount of clearance (gap) between the bus bar 1 and the circuit board 3, the bus bar 1 has a bent portion 9 such that the first region 10 is kept at a constant distance from the circuit board 3. This makes it possible to suppress the adverse effects caused by dimensional tolerances during design and the generation of stress during thermal expansion.

Furthermore, the bus bar 1 needs to have a clearance between the first region 10 and the circuit board 3 created by the bent portion 9 to ensure stable assembly. Therefore, the bus bar 1 is provided with a second terminal 8 in addition to the first terminal 7 in the first region 10 . The first terminal 7 is inserted into a through hole provided in the circuit board 3 and is electrically connected to a ground wiring pattern within the circuit board 3. The second terminal 8 serves as a support part for the bus bar 1 to fix the bus bar 1 to the circuit board 3 to prevent it from falling over, maintain the distance between the bus bar 1 and the circuit board 3, and improve the ease of assembling the entire bus bar 1. We are ensuring improvements. Further, as described above, the second terminal 8 is electrically connected to the ground wiring pattern within the circuit board 3 by contacting the GND copper foil portion 2 of the circuit board 3.

The second region 11 is a part of the bus bar 1 and is placed on the circuit board 3 in contact with the circuit board 3, and by providing a clearance between the first region 10 and the circuit board 3, ease of assembly is achieved. The unstable bus bar 1 is supported together with the second terminal 8.

Further, the second region 11 includes a pin hole 12 . The pin hole 12 is a reference hole used for positioning when mounting the connector 4 on the circuit board 3. When fixing the connector 4 and the circuit board 3 through the pin hole 12, the bus bar 1 is simultaneously tightened. The fixation of the bus bar 1 to the circuit board 3 is improved.

According to the first embodiment of the present invention described above, the following effects are achieved.

(1) The power conversion device includes a circuit board 3 having a ground wiring pattern, a conductive casing 15 that houses the circuit board 3, and a grounding bus bar 1 that electrically connects the ground wiring pattern and the casing 15. A power conversion device comprising: a grounding bus bar 1 disposed on a first surface of a circuit board 3; and a grounding bus bar 1 extending in a plane direction parallel to the first surface. , has a first region 10 that is a part spaced apart from the first surface by a predetermined distance, and the first region 10 has a first terminal 7 inserted into a through hole provided in the circuit board 3 and a first region 10 that is a part spaced apart from the first surface by a predetermined distance. A second terminal that contacts the first surface of the circuit board is provided, and the first terminal and the second terminal are electrically connected to the ground wiring pattern of the circuit board. By doing this, the number of connection points between the main body case 15 and the ground of the circuit board 3 can be increased, so that the ground impedance of the circuit can be lowered. Furthermore, compared to conventional power conversion devices, resistance to noise radiated from the circuit board 3 and noise irradiated to the board is enhanced.

(2) The grounding bus bar 1 of the power conversion device has a second region 11 placed on the first surface of the circuit board 3. By doing this, the bus bar 1 is prevented from falling over, and it is possible to ensure improved ease of assembly. Furthermore, damage that may occur due to pressure being applied to the first terminal 7 when the bus bar 1 is screwed is prevented.

(Second embodiment)
5, 6, and 7 are diagrams showing a method of fixing the circuit board 3, bus bar 1, connector 4, and main body case 15 according to the second embodiment.

FIG. 5 is a diagram regarding a method of fixing the bus bar 1, the circuit board 3, and the connector 4.

As shown in FIG. 5, the bus bar 1, the circuit board 3, and the connector 4 have a contact portion 13 in a portion other than the first screw portion 5 and the second screw portion 6, and can be screwed through this portion. Fixedness is ensured. Thereby, the bus bar 1 and the circuit board 3 are fixed in contact with each other.

(Third embodiment)
FIG. 6 is a diagram regarding a method of fixing the bus bar 1, circuit board 3, and connector 4, which is different from the second embodiment.

As shown in FIG. 6, the connector 4 has a resin tab 14 that enables connection and fixation with the circuit board 3, thereby ensuring fixity during assembly. The contact between the bus bar 1 and the connector 4 is fixed by a resin claw 14 so that the bus bar 1 and the connector 4 come into contact at a position such as a contact portion 16. Thereby, the bus bar 1 and the circuit board 3, which are sandwiched between the circuit board 3 and the connector 4, are fixed in contact with each other. Therefore, there is no need to provide a contact portion that requires screwing as shown in the second embodiment, which can contribute to downsizing of the power converter.

(Fourth embodiment)
FIG. 7 is a diagram relating to a method of assembling the bus bar 1, the circuit board 3, and the main body case 15.

The main body case 15 and the bus bar 1 have a contact portion 17 as shown in FIG. 7, and are assembled and fixed by screws or the like. As a result, the circuit board 3 and the bus bar 1, which are sandwiched between the bus bar 1 and the main body case 15, are fixed in contact with each other. Therefore, the main body case 15, bus bar 1, and circuit board 3 can be fixed all at once, contributing to the reduction of fastener parts.

According to the second, third, and fourth embodiments of the present invention described above, the following effects are achieved.

(3) The power conversion device includes a fixing member that fixes the grounding bus bar 1 and the circuit board 3 in contact with each other. By doing this, the contact between the second terminal 8 of the bus bar and the circuit board 3 can be strengthened, and noise resistance can be stably ensured.

The embodiments and various modifications described above are merely examples, and the present invention is not limited to these contents as long as the characteristics of the invention are not impaired. Furthermore, although various embodiments and modifications have been described above, the present invention is not limited to these. Other embodiments considered within the technical spirit of the present invention are also included within the scope of the present invention.

1 Bus bar 2 GND copper foil part 3 Circuit board 4 Connector 5 First screw part 6 Second screw part 7 First terminal 8 Second terminal 9 Bend part 10 First area 11 Second area 12 Pin hole 13 Contact part 14 Resin claw 15 Main case 16 Contact part 17 Contact part

Claims (2)

a circuit board having a ground wiring pattern;
a conductive casing that houses the circuit board;
A power conversion device comprising a grounding bus bar electrically connecting the ground wiring pattern and the casing,
The grounding bus bar is arranged on the first surface of the circuit board, and the grounding bus bar extends in a plane direction parallel to the first surface, and is spaced apart from the first surface by a predetermined distance. a first area that is a spaced portion ; and a second area that is placed on the first surface of the circuit board;
The first region is provided with a first terminal that is inserted into a through hole provided in the circuit board, and a second terminal that contacts the first surface of the circuit board,
The first terminal and the second terminal are electrically connected to the ground wiring pattern in a power conversion device. The power conversion device according to claim 1 ,
A power conversion device including a fixing member that fixes the grounding bus bar and the circuit board in contact with each other.

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