Power converter

Abstract

To provide a power conversion device capable of implementing enhancement of the noise removing performance and enhancement of the assemblability with an automatic assembly step taken into consideration therefor.SOLUTION: A power conversion device includes: a first connection member for connecting a noise filter and a power source connector; and a second connection member for connecting the noise filter and a smoothing capacitor. The noise filter includes: a base portion that is disposed in a recess in a casing; a bus bar portion having first and second terminal sections extending from a surface opposite to a surface opposed to a bottom surface side of a recess in the base portion, toward a direction away from the base portion; first and second magnetic body cores that are inserted through the respective terminal sections; and a filter case in which a core housing section is formed. The filter case is molded so as to expose ends of the first and second terminal sections to the outside so that the ends are connected to the first connection member and the second connection member respectively.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a power conversion device.

Background Art

[0002] When mounted on a vehicle, for example, a power conversion device is one of the devices for which cost reduction is considered. Devices for which cost reduction is considered are also required to improve the ease of mass production and the assemblability related to connection to other components. As an example of such improvement in assemblability, Patent Document 1 below discloses a configuration of an electric circuit device that can be miniaturized while effectively suppressing noise that enters the control circuit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technology described in Patent Document 1, there are problems that difficulties occur in the automatic assembly process of the device and the EMC (Electro-Magnetic Compatibility) performance cannot be fully exhibited. The present invention has been made in view of the above circumstances, and an object thereof is to provide a power conversion device that achieves both an improvement in noise removal ability and an improvement in assemblability considering the automatic assembly process.

Means for Solving the Problems

[0005] A power conversion device comprising: a power module having a power conversion circuit that converts DC power supplied from a DC power source via a power connector into AC power; a smoothing capacitor for smoothing the DC power; a noise filter for suppressing electromagnetic noise generated from the power module; and a housing having a recess for housing the noise filter, wherein the noise filter has a first connecting member for connecting the noise filter and the power connector, and a second connecting member for connecting the noise filter and the smoothing capacitor, and the noise filter has a base portion installed in the recess and a surface opposite to the bottom surface of the recess of the base portion. The device comprises a busbar portion having a first terminal portion and a second terminal portion extending from the side surface in a direction away from the base portion; a first magnetic core having a through hole through which the first terminal portion is inserted; a second magnetic core having a through hole through which the second terminal portion is inserted; and a filter case having a core housing portion in which the first magnetic core and the second magnetic core are arranged, wherein the filter case is molded so that the ends of the first terminal portion and the ends of the second terminal portion are exposed to the outside, and the first terminal portion and the second terminal portion are connected to the first connecting member and the second connecting member, respectively. [Effects of the Invention]

[0006] We can provide a power conversion device that achieves both improved noise reduction capabilities and improved assembly efficiency considering automated assembly processes. [Brief explanation of the drawing]

[0007] [Figure 1] An exploded view of a power converter according to one embodiment of the present invention. [Figure 2] Diagram illustrating the arrangement of magnetic cores mounted on a noise filter according to one embodiment of the present invention. [Figure 3] Diagram illustrating a filter case according to one embodiment of the present invention. [Figure 4] Diagram illustrating the resin used to fill a noise filter, according to one embodiment of the present invention.

[0008] Embodiments of the present invention will be described below with reference to the drawings. The following description and drawings are illustrative for illustrating the present invention, and have been omitted and simplified as appropriate for clarity of explanation. The present invention can also be carried out in various other forms. Unless otherwise specified, each component may be singular or plural.

[0009] The positions, sizes, shapes, and ranges of the components shown in the drawings may not represent their actual positions, sizes, shapes, and ranges in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, and ranges disclosed in the drawings.

[0010] (One embodiment of the present invention and its overall configuration) (Figure 1) The power conversion device 1 comprises a power module 2 having a power conversion circuit that converts DC power supplied from a DC power source (not shown) via a power connector into AC power, a smoothing capacitor 7 for smoothing the DC power, a noise filter 3 for suppressing electromagnetic noise generated from the power module 2, and a housing 8 having a first recess 5 for housing the noise filter 3.

[0011] The housing 8 has a second recess 6 for housing a smoothing capacitor 7, in addition to the first recess 5. The first recess 5 and the second recess 6 are filled with potting resin 4, and the noise filter 3 is fixed to the housing 8 by immersing it in the first recess 5 and the smoothing capacitor 7 in the second recess 6. The potting resin 4 may be PPS (Poly Phenylene Sulfide), which has a higher thermal conductivity than air. The power module 2 is housed in a separate space in the housing 8 from the first recess 5 and the second recess 6.

[0012] The power converter 1 includes a first connecting member 11 that connects the noise filter 3 to a power connector (not shown), and a second connecting member 12 that connects the noise filter 3 to a smoothing capacitor 7. The first connecting member 11 is fixed to the housing 8. The first connecting member 11 has terminals that are shaped to face the terminals of the noise filter 3. The terminals of the first connecting member 11 and the terminals of the noise filter 3 are welded together, thereby electrically connecting the noise filter 3 to the DC power supply.

[0013] The power module 2 is fixed to the housing 8 and electrically connected to the second connecting member 12. The second connecting member 12 is positioned on the top surface of the smoothing capacitor 7 and is fixed to the housing 8. The terminals of the second connecting member 12 are welded to the terminals of the smoothing capacitor 7, thereby electrically connecting them. The second connecting member 12 has terminals that face each other, similar to the first connecting member 11, and the terminals of the second connecting member 12 and the terminals of the noise filter 3 are welded together, thereby electrically connecting the noise filter 3 to the power module 2 and the smoothing capacitor 7.

[0014] (Figure 2) The molded busbar filter case 19 has a first terminal portion 21 and a second terminal portion 22. The filter case 19 also has a core housing portion 9 formed around the first terminal portion 21 and the second terminal portion 22, which houses the magnetic cores 14 and 15.

[0015] The first magnetic core 14 and the second magnetic core 15 each have through holes 14a and 15a, respectively. As the first magnetic core 14 and the second magnetic core 15 are placed in the core housing 9, the through holes 14a and 15a are inserted into the first terminal portion 21 and the second terminal portion 22. At this time, the bottom surfaces of the first magnetic core 14 and the second magnetic core 15 that contact the bottom of the filter case 19 are parallel to the base portion. This results in a layout in which the magnetic cores 14 and 15 are positioned lying down in the core housing 9.

[0016] In this way, the first magnetic core 14 and the second magnetic core 15 inserted and fixed in the core accommodating portion 9 make the magnetic core of the noise filter 3 into two, so the noise removal ability is improved. Further, the bus bar terminal portion of the noise filter 3 is formed in a shape that penetrates upward from below with respect to the through holes 14a and 15a of the magnetic cores 14 and 15, respectively, and the DC input terminal connected to the DC power supply and the terminal connected to the bus bar on the power module 2 side extend uniformly in the upper surface direction. Therefore, a partition for positioning the magnetic cores 14 and 15 is provided, and it becomes easy to install the magnetic cores 14 and 15 in the core accommodating portion 9.

[0017] Also, with such a configuration, since the contact area with the potting resin 4 described above is enlarged, the cooling ability with respect to the heat generation of the power module 2 is improved, and the generated temperature can be reduced. Similarly, the cooling property is improved by reducing the distance between the housing 8, which is a die-cast case, and the bottom surfaces of the magnetic cores 14 and 15 as a heat escape port.

[0018] Also, by doing so, the heavy magnetic cores 14 and 15 are symmetrically arranged around the filter capacitor 16 and the through holes 14a and 15a are arranged upward, so that the deviation of the center of gravity position of the magnetic cores 14 and 15 in the filter case 19 is prevented, and the seismic resistance is improved by lowering the center of gravity.

[0019] At least one of the first terminal portion 21 or the second terminal portion 22 is formed with a taper 17 that spreads toward the bottom surface of the base portion described later by resin molding at the root portion of each of the terminal portions 21 and 22. By having such a taper 17, the insertion of the magnetic cores 14 and 15 into the first terminal portion 21 or the second terminal portion 22 becomes easy, and at the same time as inserting into the first terminal portion 21 and the second terminal portion 22, the positioning of the magnetic cores 14 and 15 in the core accommodating portion 9 can be achieved, which contributes to the improvement of the assembly property.

[0020] The filter case 19 forms a standing portion 13 at a position between the first magnetic core 14 and the second magnetic core 15. The standing portion 13 has a third terminal portion 23. Also, a third bus bar, which will be described later, is formed so as to span the upper portions of the standing portions 13. The third bus bar is connected to the ground potential (GND) and has a fourth terminal portion 24.

[0021] The filter capacitor 16 is disposed in the space between the standing portions 13. Of the two terminals of the filter capacitor 16, one terminal is welded to the third terminal portion 23 and the other terminal is welded to the fourth terminal portion 24.

[0022] With such a configuration having bus bars extending in the same direction, it is not necessary to add a process of changing the angle of the welding torch or the workpiece in the connection operation, and since it is a welded connection, screws and nuts are not required, and the number of parts required for assembling the core bus bar excluding around the capacitor can be reduced. Also, thereby, miniaturization, low profile, shortening of the cycle time, and simplification of the assembly line improve the assembly property and productivity.

[0023] (Fig. 3) Fig. 3(a) is an explanatory diagram of the filter case 19 in the noise filter 3, and Fig. 3(b) is an explanatory diagram of the non-molded bus bar of the filter case 19. The filter case 19 is a molded bus bar that houses the magnetic cores 14 and 15. The filter case 19 is molded such that the ends of the first terminal portion 21 and the ends of the second terminal portion 22 are exposed to the outside. The non-molded first terminal portion 21 and second terminal portion 22 are welded to the first connection member 11 and the second connection member 12 described above, respectively.

[0024] The filter case 19 has a bus bar portion 20. The bus bar portion 20 is a configuration before the filter case 19 is resin-molded, and includes a base portion 30 installed in the first recess 5, and the first terminal portion 21 and the second terminal portion 22 that extend in a separating direction from the surface of the base portion 30 opposite to the surface of the base portion 30 facing the bottom surface side of the first recess 5.

[0025] The busbar section 20 has an upright section 13 in which a part of the base section 30 is erected in a separation direction in the central part, and a third terminal section 23 extending from the upright section 13 in a separation direction. This separation direction is, for example, the vertical direction, and is shown as the first direction 18 in Figure 3(b).

[0026] The busbar section 20 has a first busbar 31, a second busbar 32, and a third busbar 33. The first busbar 31, the second busbar 32, and the third busbar 33 are molded with PPS or other resin material to form a molded busbar as a single integrated part, which functions as a filter case 19. A hole 19a is provided in the center between the upright sections 13 formed by the first busbar 31 and the second busbar 32. As shown in Figure 3(a), the shape of this hole 19a is maintained even in the state of the molded busbar. The aforementioned filter capacitor 16 is installed in this hole 19a.

[0027] The third busbar 33 spans the upper parts of the upright portions 13 formed by the first busbar 31 and the second busbar 32, and is supported by resin molding. The third busbar 33 also has a fourth terminal portion 24.

[0028] Terminals 21 to 24 all extend toward the first direction 18. The first terminal 21 and the second terminal 22 extend upward and are welded to the first connecting member 11 and the second connecting member 12. Similarly, the third terminal 23 and the fourth terminal 24 also extend upward and are connected to the terminals of the filter capacitor 16, respectively.

[0029] Because the shape of the connecting busbars is all oriented in a consistent direction, the amount of tool movement required during assembly is reduced, and the connection work can be performed without the need to change the angle of the torch or workpiece or to move it during welding. In addition, since no other parts are needed to accommodate the magnetic cores 14 and 15 during assembly, the number of welding points is reduced, making assembly easier during the welding process. Furthermore, the number of times the busbars are bent can be reduced, improving the accuracy of the assembly.

[0030] (Figure 4) Figure 4(a) shows the components shown in Figure 1 housed in the power converter 1, and Figure 4(b) is a cross-sectional view of AA in Figure 4(a). The potting resin 4 filled in the first recess 5 and the core housing 9 is in contact with the magnetic cores 14 and 15, the filter capacitor 16, and the base portion 30. The bottom surface of the filter capacitor 16 is housed in the first recess 5 and is in contact with the housing 8.

[0031] In this way, the potting resin 4 causes the heat-generating filter capacitor 16 and magnetic cores 14 and 15 to come into contact with the die-cast case housing 8. The potting resin 4 also plays a role in bonding the filter capacitor 16 and magnetic cores 14 and 15 to the housing 8, thereby increasing the contact area. This not only improves the heat dissipation of the power converter 1 but also contributes to improved vibration resistance and EMC performance of the noise filter 3. Furthermore, it contributes to improved assembly without compromising the performance of the noise filter 3. In addition, since the mounting position of the filter capacitor 16 is lower than before, it contributes to the lower profile and miniaturization of the power converter 1.

[0032] According to the embodiment of the present invention described above, the following effects are achieved.

[0033] (1) The power module 2 has a power conversion circuit that converts DC power supplied from a DC power source via a power connector into AC power, a smoothing capacitor 7 that smooths the DC power, a noise filter 3 that suppresses electromagnetic noise generated from the power module 2, and a housing 8 that has a recess 5 that houses the noise filter 3. The power module 8 also has a first connecting member 11 that connects the noise filter 3 to the power connector, and a second connecting member 12 that connects the noise filter 3 to the smoothing capacitor 7. The noise filter 3 includes a busbar portion 20 having a base portion 30 installed in the recess 5, a first terminal portion 21 and a second terminal portion 22 extending in a direction away from the base portion 30 from the surface of the base portion 30 opposite to the surface facing the bottom of the recess 5, a first magnetic core 14 having a through hole through which the first terminal portion 21 is inserted, a second magnetic core 15 having a through hole through which the second terminal portion 22 is inserted, and a filter case 19 having a core housing portion 9 in which the first magnetic core 14 and the second magnetic core 15 are arranged. The filter case 19 is molded so that the ends of the first terminal portion 21 and the ends of the second terminal portion 22 are exposed to the outside, and the first terminal portion 21 and the second terminal portion 22 are connected to a first connecting member 11 and a second connecting member 12, respectively. In this way, we can provide a power converter 1 that achieves improved noise reduction capabilities and improved assembly efficiency considering the automated assembly process.

[0034] (2) The busbar section 20 has an upright section 13 which is a part of the base section 30 erected in the isolation direction, and a third terminal section 23 which extends from the upright section 13 in the isolation direction. The filter case 19 has a filter capacitor 16 which is positioned between the first magnetic core 14 and the second magnetic core 15, with one end connected to the third terminal section 23 and the other end connected to ground potential. In this way, the busbar shape can be simplified while improving ease of assembly.

[0035] (3) At least one of the first terminal portion 21 or the second terminal portion 22 has a taper 17 formed by resin molding that widens toward the bottom surface of the base portion 30. This makes it easier to position the magnetic cores 14 and 15 and improves ease of assembly.

[0036] (4) The recess 5 and the core housing 9 are filled with potting resin 4. This makes it possible to achieve both improved cooling performance and improved vibration resistance.

[0037] (5) The filter condenser 16 is housed in the recess 5. This configuration allows for both improved cooling and a lower profile.

[0038] It should be noted that the present invention is not limited to the embodiments described above, and various modifications and combinations of other configurations can be made without departing from the spirit of the invention. Furthermore, the present invention is not limited to having all the configurations described in the embodiments described above, and may also include configurations in which some of those configurations are omitted. [Explanation of Symbols]

[0039] 1. Power converter 2 Power Modules 3. Noise filter 4. Potting resin 5. First recess 6. Second recess 7. Smoothing Capacitor 8 cabinets 9 Core housing 11 First connecting member 12 Second connecting member 13. Erecting section 14. First magnetic core 14a Through hole of the first magnetic core 15. Second magnetic core 15a Through hole of the second magnetic core 16 Filter capacitors 17 Taper 18 1st direction 19 Filter Case 19a Hole 20 Bass Club 21 First terminal section 22 Second terminal section 23 Third terminal section 24. Fourth terminal section 30 Base section 31 First bus 32 Second bus 33 Third Bus Bar

Claims

1. A power conversion device comprising: a power module having a power conversion circuit that converts DC power supplied from a DC power source via a power connector into AC power; a smoothing capacitor for smoothing the DC power; a noise filter for suppressing electromagnetic noise generated from the power module; and a housing having a recess for housing the noise filter, It has a first connecting member that connects the noise filter and the power connector, and a second connecting member that connects the noise filter and the smoothing capacitor, The noise filter comprises a base portion installed in the recess, a busbar portion having a first terminal portion and a second terminal portion extending in a direction away from the base portion from a surface opposite to the surface of the base portion facing the bottom surface of the recess, a first magnetic core having a through hole through which the first terminal portion is inserted, a second magnetic core having a through hole through which the second terminal portion is inserted, and a filter case having a core housing portion in which the first magnetic core and the second magnetic core are arranged. The filter case is molded such that the ends of the first terminal portion and the ends of the second terminal portion are exposed to the outside. The first terminal portion and the second terminal portion are connected to the first connecting member and the second connecting member, respectively. Power converter.

2. The busbar portion has an upright portion in which a part of the base portion is erected in the direction of separation, and a third terminal portion extending from the upright portion in the direction of separation. The filter case has a filter capacitor positioned between the first magnetic core and the second magnetic core, with one end connected to the third terminal and the other end connected to ground potential. The power conversion device according to claim 1.

3. At least one of the first or second terminal portion is formed by resin molding to create a taper that widens toward the bottom surface of the base portion. The power conversion device according to claim 1.

4. The recess and the core housing are filled with potting resin. The power conversion device according to claim 1.

5. The filter capacitor is housed in the recess. The power conversion device according to claim 2.

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