JP2007028785A - Power converter and method for manufacturing power converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power converter for reducing restrictions on a shape of a bus bar and a constitution of an external terminal, facilitating a waterproof countermeasure and acquiring the stable accuracy. <P>SOLUTION: A control board 4 is disposed in an upper part of a power board 6 having switching elements 7, drives and controls the switching elements 7. A heat sink 10 dissipates heat from the power board 6. A bus bar 1 has one end 1a connected between the switching elements 7 on the power board 6 and the other end 1b having an external terminal 12 connected to the outside. A magnetic flux collecting core 3 has an air gap 3a for collecting a magnetic flux generated by a current flowing in the bus bar 1. A magnetic flux detecting element 2 detects the magnetic flux in the magnetic flux collecting core 3, and is connected to the control board 4. The bus bar 1 and the magnetic flux collecting core 3 are molded and integrated into a resin case 8. One end 1a of the bus bar 1 is connected to the power board 4 through a bent part 11. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power conversion device using a magnetic detection element and a method of manufacturing the power conversion device, and in particular, there are few restrictions on the shape of the bus bar and the configuration of the external terminals, and waterproof measures can be easily obtained and stable accuracy can be obtained. It is something that can be done.

  A power conversion device with a built-in current sensor used in a conventional vehicle power conversion device includes a bus bar as a conductive member, a magnetic detection element, a magnetic flux collecting core configured to surround the bus bar, a control board for the power conversion device, A lead terminal for electrically connecting the output signal and power supply of the magnetic detection element to the control board, a power board connected to the bus bar, a switching element mounted on the power board, a resin case molded around the entire power converter, It consists of a heat sink that cools the heat generation of the power board and becomes the foundation of the structure of the power converter.

  In a conventional method for assembling a power converter, after molding a resin case, the magnetic core and the bus bar are fitted into specified positions, and then a waterproof lid that is a part of the resin case is mounted on the magnetic core and the bus bar. . Next, the control board on which the magnetic detection element is mounted is assembled by disposing the magnetic detection element in the gap of the magnetic flux collecting core.

  Next, the operation of a conventional power conversion device with a built-in current sensor will be described. First, power supplied from an external DC power supply from an external terminal of the bus bar is introduced into the power board, converted into AC by a switching element driven by the control board, and output to another bus bar. Further, the AC power supplied from the external terminal of the bus bar is rectified and output from the external terminal of another bus bar to an external DC power source. At this time, the magnetic flux generated by the current flowing through the bus bar is collected in the magnetic collecting core and detected by the magnetic detection element, and this detected value is used as a control parameter on the control board (for example, see Patent Document 1).

Japanese Patent Laid-Open No. 11-127583

  The conventional power converter with a built-in current sensor is configured as described above, so in order to assemble the busbar and magnetic flux collecting core in the resin case, a completely waterproof specification may be required depending on the usage environment. In this case, the interface for waterproofing is complicated, and the magnetism collecting core is inserted into the resin case afterwards, so that the positional accuracy is poor and the caulking or resin fixing in the subsequent process is necessary for secure holding. In the assembly process, it led to time loss and cost increase. Furthermore, it is difficult to improve the position system of the magnetic sensing element mounted on the control board with respect to the gap portion of the magnetic flux collecting core. In addition, since the magnetism collecting core and the bus bar are assembled through the resin case at the time of assembly, the bending shape of the bus bar and the shape of the external terminal portion are less flexible, and the configuration of the external terminals made of bolts is difficult.

  The present invention has been made to solve the above-described problems, and there are few restrictions on the shape of the bus bar and the configuration of the external terminals, and the power conversion device can easily obtain waterproof measures and obtain stable accuracy. And it aims at providing the manufacturing method of a power converter device.

  The present invention includes a power board having a switching element that converts a direct current and an alternating current, a control board that is disposed above the power board and connected to the switching element and controls driving of the switching element, and a lower part of the power board. A heat sink that dissipates heat from the power board, a bus bar having one end connected between the switching elements of the power board and the other end connected to the outside, and a current of the bus bar arranged to surround the bus bar A magnetic flux collecting core that collects magnetic flux generated by the magnetic flux collecting core, a magnetic sensing element that detects the magnetic flux of the magnetic flux collecting core and is connected to the control board, and a power board and a power board for protecting the power board and the control board from the outside. In a power converter including a resin case disposed so as to surround an outer periphery of a control board, a bus bar and a magnetic flux collector The bus bar is integrally formed with the resin case, one end of the bus bar is exposed from the resin case to the power board side and is connected to the power board with a vent portion, and the other end of the bus bar is exposed from the resin case to the outside side and external terminals Is formed.

  The power converter of the present invention includes a power board having a switching element for converting a direct current and an alternating current, a control board disposed on the power board and connected to the switching element to drive and control the switching element, and a power board A heat sink that dissipates heat from the power board, a bus bar having one end connected between the switching elements of the power board and an external terminal connected to the outside at the other end, and the bus bar. In order to protect the power board and the control board from the outside, the magnetic flux collecting core having a gap for collecting the magnetic flux generated by the current of the bus bar, the magnetic flux of the magnetic flux collecting core, and the magnetic detection element connected to the control board And a resin case disposed so as to surround the outer periphery of the power board and the control board. -And the magnetic flux collecting core are integrally formed in the resin case, one end of the bus bar is exposed from the resin case to the power board side and is connected to the power board with a vent, and the other end of the bus bar is exposed from the resin case to the outside side Since the external terminal is formed, there are few restrictions on the shape of the bus bar and the configuration of the external terminal, and waterproof measures can be easily taken and stable accuracy can be obtained.

Embodiment 1 FIG.
Embodiments of the present invention will be described below. FIG. 1 is a side view showing a section of a part of a power conversion device with a built-in current sensor according to Embodiment 1 of the present invention, and FIG. It is a perspective view which shows the structure of the state before performing. In the figure, a power board 6 having a plurality of switching elements 7 for converting a direct current and an alternating current provided on the upper surface, and an upper part of the power board 6 connected to each switching element 7 and connected to each switching element 7. The control board 4 that controls the driving of the power board 6 and the heat board 10 that is disposed under the power board 6 to dissipate and cool the heat generated by the power board 6, serve as a base of the structure of the power converter, and one end 1 a of the power board 6. A bus bar 1 connected between the switching elements 7 and having an external terminal 12 connected to the outside at the other end 1b, and a gap 3a that is disposed so as to surround the bus bar 1 and collects magnetic flux generated by the current of the bus bar 1. The magnetic flux collecting core 3 formed at a position facing the control board 4, and a magnet connected to the control board 4 and disposed in the gap 3 a so as to detect the magnetic flux of the magnetic flux collecting core 3. A detecting element 2, and similar to the resin case 8 arranged so as to surround the outer periphery of the power board 6 and the control board 4 in order to protect the power board 6 and the control board 4 from the outside.

  In the first embodiment, the bus bar 1 and the magnetic flux collecting core 3 are integrally formed in advance with the resin case 8. One end 1a of the bus bar 1 is exposed from the resin case 8 to the power board 6 side and is connected to the power board 6 with a vent portion 11, and the other end 1b of the bus bar 1 is exposed from the resin case 8 to the outside side. External terminals 12 are formed. The magnetic detection element 2 is connected by a lead terminal 40 that is electrically joined to the control board 4 in order to obtain an output signal and a power source. The lead terminal 40 is fixed to the control board 4 via a guide 42 fixed to the control board 4. Further, a positioning hole 80 is formed in the resin case 8 at a position interlinking with the magnetic path of the gap 3 a formed by the magnetic flux collecting core 3, and the magnetic detection element 2 is inserted and disposed in the positioning hole 80. Yes.

  Next, the manufacturing method of the power converter device of Embodiment 1 comprised as mentioned above is demonstrated. First, when the resin case 8 is molded, the magnetic core 3 and the bus bar 1 are positioned by a molding die and integrally molded. At the same time, the positioning hole 80 is also formed. Next, the power substrate 6 on which the switching element 7 is formed is placed on the heat sink 10. Next, the resin case 8 formed so as to surround the outer periphery of the power substrate 6 on the heat sink 10 is placed. The bus bar 1 and the power board 6 are connected. Next, the magnetic detection element 2 is inserted into the positioning hole 80, and the control board 4 on which the guide 42 is mounted is disposed. At this time, the lead terminal 40 of the magnetic detection element 2 is guided by the guide 42 and soldered to the control board 4.

  In the operation of the power conversion apparatus according to the first embodiment configured as described above, first, power supplied from an external DC power source (not shown) is introduced to the power board 6 from the external terminal 12 of the bus bar 1. Next, power is converted into alternating current by the switching element 7 driven by the control board 4 and output from the external terminal 12 of the other bus bar 1 to the outside. Also, the AC power supplied from the bus bar 1 is rectified and output to the DC power source via the other bus bar 1. At this time, the magnetic flux generated by the current flowing through the bus bar 1 is collected in the magnetic collecting core 3 and detected by the magnetic detection element 2, and the value is used as a control parameter on the control board 4.

  According to the power conversion device of the first embodiment configured as described above, since the bus bar and the magnetic flux collecting core are integrally formed in the resin case, a process such as penetrating the magnetic flux collecting core into the bus bar is omitted. A power converter can be assembled. Although the bus bar is integrally formed with the resin case as described above, there is a concern about stress relaxation between the bus bar and the power board. However, since the bus bar includes the vent portion, the vent portion can bear the stress relaxation. In addition, since the positioning hole in which the magnetic detection element is positioned is formed in advance with a precise mold when the resin case is molded, the power conversion device can be assembled with high positional accuracy. Further, at this time, since the gap portion of the magnetic flux collecting core is formed at a position facing the control board, a magnetic detection element for connection to the control board can be easily provided.

Embodiment 2. FIG.
FIG. 3 is a side view showing a cross section of a part of the power conversion device with a built-in current sensor according to Embodiment 2 of the present invention, and FIG. FIG. 5 is a perspective view showing a configuration of a bus bar assembly part of the power conversion device with a built-in current sensor shown in FIG. 3. In the figure, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. The magnetic flux collecting core 30 is composed of C-shaped divided magnetic flux collecting cores 31 and 32, and is divided so as to surround the substantially vertical direction portion 1c of the bending structure portion having the substantially vertical direction portion 1c continuous with the horizontal portion of the bus bar 1. The magnetic cores 31 and 32 are arranged, and the magnetic collecting core 30 is arranged. By disposing the bus bar 1 serving as a current path around the magnetic collecting core 30 by arranging at such a location, if 360 ° is considered as one turn, it is wound by 90 °, that is, 1/4 turn. A magnetic flux collecting effect can be expected from this bus bar. In addition, since the detection is performed by the magnetic detection element 2 at the front and rear portions of the bent structure portion of the bus bar as described above, it greatly affects the magnetic flux density.

  Next, the manufacturing method of the power converter device of Embodiment 2 comprised as mentioned above is demonstrated. First, the bus bar 1 and the magnetic flux collecting core 30 composed of the divided magnetic flux collecting cores 31 and 32 are integrally formed in advance as the bus bar assembly portion 100. This is because the magnetic flux collecting core 30 is composed of two magnetic flux collecting cores 31 and 32, which are two parts. Therefore, by integrally forming the resin 81 with the pre-positioning hole 82 in advance, This is because the formation of the resin case 8 is simple. In the first embodiment as well, it goes without saying that the bus bar and the magnetism collecting core may be integrally formed in advance, and the resin case may be integrally formed after the bus bar assembly portion is formed. Next, as in the first embodiment, when the resin case 8 is molded, the bus bar assembly part 100 in which the magnetic core 30 and the bus bar 1 are integrally molded is positioned by a molding die and integrally molded. At the same time, a positioning hole 80 continuous with the preliminary positioning hole 82 is also formed. Next, the power substrate 6 on which the switching element 7 is formed is placed on the heat sink 10. Next, the resin case 8 formed so as to surround the outer periphery of the power substrate 6 on the heat sink 10 is placed. The bus bar 1 and the power board 6 are connected. Next, the magnetic detection element 2 is inserted into the positioning hole 80, and the control board 4 on which the guide 42 is mounted is disposed. At this time, the lead terminal 40 of the magnetic detection element 2 is guided by the guide 42 and soldered to the control board 4.

  According to the power conversion device of the second embodiment configured as described above, the same effect as that of the first embodiment can be obtained. There are no restrictions. In addition, since the bus bar assembly portion in which the magnetic flux collecting core and the bus bar are integrally molded in advance is configured, it is possible to easily form the magnetic flux collecting core and the bus bar when integrally molded in the resin case. Further, since the magnetic flux collecting core is disposed in the substantially vertical direction portion, a magnetic flux collecting effect can be expected.

The side view which shows a part of electric power converter with a built-in current sensor in Embodiment 1 of this invention in a cross section. The perspective view which shows the structure of the state before arrange | positioning the control board of the power converter built in the current sensor shown in FIG. The side view which shows a part of electric power converter with a built-in current sensor in Embodiment 2 of this invention in a cross section. The perspective view which shows the structure of the state before arrange | positioning the control board of the power converter built in the current sensor shown in FIG. The perspective view which showed the structure of the bus-bar assembly part of the power converter device with a built-in current sensor shown in FIG.

Explanation of symbols

1 bus bar, 1a one end, 1b other end, 1c substantially vertical direction part, 2 magnetic detection element,
3,30 magnetic flux collecting core, 3a gap, 4 control board, 6 power board,
7 switching element, 8 resin case, 10 heat sink, 11 vent part,
12 external terminals 31, 32 split magnetic flux collecting cores, 80 positioning holes,
100 Busbar assembly part.

Claims (6)

A power board having a switching element for converting a direct current and an alternating current, a control board disposed on the power board and connected to the switching element for driving and controlling the switching element, and a lower part of the power board. A heat sink for dissipating heat from the power board, a bus bar having one end connected between the switching elements of the power board and an external terminal for connecting to the outside at the other end, and disposed so as to surround the bus bar. A magnetic flux collecting core having a gap that collects magnetic flux generated by the current of the bus bar, a magnetic detection element that detects the magnetic flux of the magnetic flux collecting core and is connected to the control board, and the power board and the control board from the outside Electric power provided with a resin case disposed so as to surround the outer periphery of the power board and the control board for protection In the conversion device, the bus bar and the magnetism collecting core are integrally formed with the resin case, and one end of the bus bar is exposed from the resin case to the power board side and is provided with a vent portion to be connected to the power board. The other end is exposed to the outside from the resin case to form the external terminal. A positioning hole is formed in the resin case at a position interlinking with the magnetic path of the gap formed by the magnetic collecting core, and the magnetic detection element is inserted into the positioning hole formed in the resin case. The power converter according to claim 1, wherein the power converter is provided. The power converter according to claim 1, wherein the gap portion of the magnetism collecting core is formed at a position facing the control board. 4. The magnetic flux collecting core according to claim 1, wherein the magnetic flux collecting core is formed of a plurality of divided magnetic flux collecting cores, and the divided magnetic flux collecting cores are disposed so as to surround the bus bar. The power converter described. A portion of the bus bar is formed with a bent structure portion having a substantially vertical direction portion continuous with a horizontal portion, and is disposed so as to surround the divided magnetic flux collecting core in the substantially vertical direction portion of the bus bar. The power conversion device according to claim 4. 6. The method of manufacturing a power conversion device according to claim 1, wherein the resin case constitutes a bus bar assembly part in which the magnetic flux collecting core and the bus bar are integrally formed, and the bus bar assembly part is integrated with the resin case. A method for manufacturing a power conversion device, characterized by being formed by molding.

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