Patent Description:
<CIT> discloses an electric power converter having an inverter, a smoothing capacitor, and a metal housing configured to house the inverter and the smoothing capacitor. In this electric power converter, the smoothing capacitor and the inverter are connected by a conductor portion, and in order to ensure an insulation property between the conductor portion and the metal housing, an insulating member is placed between the conductor portion and the housing.

However, with the electric power converter described above, the insulating member which is a separate member is placed between the conductor portion and the housing. Thus, the number of constituent parts is increased and manufacturing cost is increased.

Meanwhile, it is also possible to ensure the insulation property by increasing an insulation space distance of the conductor portion and the metal housing without using an insulating member. However, in this case, there is a need for a large space and the size of the converter is increased.

Document <CIT> describes an in-vehicle power conversion device which attempts reducing size and improving freedom in designing. This in-vehicle power conversion device comprises a housing that forms a housing section for housing a drive section (a smoothing capacitor and a power module), which converts and transmits power; and a plurality of bus bars that connect a housing input/output section (a battery-side terminal section and a motor-side terminal section) for inputting/outputting power, and the drive section (the smoothing capacitor and the power module) to each other. The in-vehicle power conversion device is characterized in that the bus bars (a first bus bar, second bus bar, and a third bus bar) are respectively provided with heat dissipating sections that are disposed along the housing such that, outside of the housing section, heat can be transferred to the housing.

Document <CIT> proposes a member that contains electronic components. using the member, when, for example, a vehicle or the like carrying electronic components such as an inverter collides with an external object, there is prevented damage to a housing containing the electronic components, which would otherwise occur due to interfering objects. Furthermore, the disclosed member can dissipate heat produced by the contained electronic components. The member includes a housing for containing electronic components, a cooling passage that is provided inside the housing and uses a refrigerant to cool the electronic components, and a heat dissipation part that dissipates heat from the cooling passage and prevents the housing from being damaged by impacts from external interfering objects.

Document <CIT> discloses a vehicle-mounted electric system, wherein a power module constructs a pressurizing tool by laminating an elastic member as well as a DC positive-side wiring member and DC negative-side wiring member in which currents flow in opposite directions. The pressurizing tool presses a first fixing tool, and then the first fixing tool presses semiconductor equipment. The semiconductor equipment is fixed to a heat dissipating member with its heat dissipating surface brought into surface contact with side wall surfaces and of the heat dissipating member. The power module can enhance heat dissipation between a heat dissipating member and semiconductor equipment, and enables the semiconductor equipment to be fixed to the heat dissipating member without adding other components to the power module.

In consideration with the above problem, an object of the present invention is to provide an electric power converter capable of reducing cost and saving a space while ensuring an insulation property between a conductor portion connected to a smoothing capacitor and a housing.

The object underlying the present invention is achieved by an electric power converter according to independent claim <NUM>. Preferred embodiments are defined in the respective dependent claims.

According to an aspect of this invention, there is provided an electric power converter that includes an inverter which includes plural electric parts, a smoothing capacitor configured to smooth electric power, a housing configured to house the inverter and the smoothing capacitor and a first conductor portion configured to connect the smoothing capacitor and the inverter. The housing includes a base portion made of a resin material and a cover portion attached to the base portion to cover the inverter and the smoothing capacitor. The inverter and the smoothing capacitor are mounted on a mount surface of the base portion. The first conductor portion is placed in the vicinity of or in contact with the base portion of the housing in the middle of connection between the smoothing capacitor and the inverter. The housing comprises a metal thin plate formed on a lower surface of the base portion opposite the mount surface. The metal thin plate is larger than an outer shape of the lower surface of the base portion and functions as a bottom plate of the cover portion. A stepped portion having an end surface abutted with the mount surface of the base portion is formed in an inside part of the side wall of the cover portion and a leading end surface of the side wall is abutted with an outer peripheral edge of the thin plate. The first conductor portion is placed in the vicinity of or in contact with the mount surface of the base portion of the housing in the middle of connection between the smoothing capacitor and the inverter. The base portion comprises a first coolant flow passage through which a coolant that cools the inverter can flow which is formed below a part where the inverter is mounted.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, etc..

With reference to <FIG>, an electric power converter <NUM> according to a first embodiment of the present invention will be described.

<FIG> and <FIG> are schematic sectional views of the electric power converter according to the first embodiment. <FIG> is a sectional view of a part including input conductor portions, and <FIG> is a sectional view of a part including output conductor portions.

As shown in <FIG> and <FIG>, the electric power converter <NUM> includes an inverter <NUM>, a smoothing capacitor <NUM>, and a housing <NUM>, and disposed on a vehicle, etc..

The inverter <NUM> and the smoothing capacitor <NUM> are housed in the housing <NUM>. The inverter <NUM> and the smoothing capacitor <NUM> are electrically connected to each other by plural conductor portions <NUM> (first conductor portions), and the smoothing capacitor <NUM> and a power source <NUM> outside the housing are electrically connected to each other by plural conductor portions <NUM>, <NUM> (second conductor portions).

The inverter <NUM> includes plural electric parts, including a power module <NUM> in which semiconductor devices are built and a control board <NUM> which includes a control circuit, and has a function of converting electric power into a direct current or an alternate current.

The power module <NUM> is formed by combining the plural semiconductor devices. The power module <NUM> is mounted on a substrate <NUM>, and fixed onto the substrate <NUM> by bolts, etc. The substrate <NUM> is fixed to a base portion <NUM> of the housing <NUM> to be described later by bolts, etc. The power module <NUM> is electrically connected to the control board <NUM> and connected to the smoothing capacitor <NUM> via the conductor portions <NUM>. The conductor portions <NUM> are fixed to the power module <NUM> by bolts, etc. at a terminal portion <NUM> provided in the power module <NUM>.

The smoothing capacitor <NUM> includes a capacitor element <NUM>, a filler <NUM>, and a capacitor case <NUM>, and is arranged in line with the inverter <NUM> in the substantially horizontal direction. The capacitor case <NUM> is made of resin such as polyphenylene sulfide (PPS) and polyphthalamide (PPA), and houses the capacitor element <NUM>. The capacitor element <NUM> is connected to the power module <NUM> of the inverter <NUM> via the conductor portions <NUM> and connected to the power source <NUM> outside the housing <NUM> via the conductor portions <NUM> and the conductor portions <NUM>. The filler <NUM> is, for example, a potting material containing silicon, fills the periphery of the capacitor element <NUM> and fixes the capacitor element <NUM> in the capacitor case <NUM>.

The housing <NUM> includes the base portion <NUM> on which the inverter <NUM> and the smoothing capacitor <NUM> are mounted, a cover portion <NUM> attached to the base portion <NUM> to cover the inverter <NUM> and the smoothing capacitor <NUM>, and a thin plate <NUM> provided on a lower surface of the base portion <NUM>, the thin plate functioning as a bottom plate of the cover portion <NUM>.

The base portion <NUM> is made of an electrically-insulating resin material such as polyphenylene sulfide (PPS) and polyphthalamide (PPA) as a plate-like member, and the inverter <NUM> and the smoothing capacitor <NUM> are disposed on a mount surface <NUM>. The base portion <NUM> includes a cooling passage <NUM> (first coolant flow passage) through which cooling water (coolant) that cools the inverter <NUM> flows below a part where the inverter <NUM> is disposed. On a lower surface <NUM> of the base portion <NUM>, the metal thin plate <NUM> made of aluminum, etc. which is larger than an outer shape of the lower surface <NUM> is provided.

On an upper surface of the cooling passage <NUM> of the base portion <NUM>, the substrate <NUM> having a larger outer shape than the cooling passage <NUM> is installed, and the substrate <NUM> is fastened to the base portion <NUM> by bolts, etc. Fins <NUM> are provided in a lower portion of the power module <NUM>. Plural holes through which the fins <NUM> pass are provided in the substrate <NUM>, and the fins <NUM> are brought in contact with the cooling water in the cooling passage <NUM> through the holes. Although the fins <NUM> are preferably provided in the power module <NUM> to be brought into contact with the cooling water, the present invention is not necessarily limited to this. No fins <NUM> may be provided.

The cover portion <NUM> is made of a metal material such as aluminum, and attached to the base portion <NUM> to cover the periphery of the inverter <NUM> and the smoothing capacitor <NUM>. The cover portion <NUM> includes an upper wall <NUM> and a side wall <NUM>. An opening 323a (<FIG>) opened to let input conductor portions 30a connected to the power source <NUM> pass through, and an opening 323b (<FIG>) opened to let output conductor portions 30b connected to the power source <NUM> pass through are formed in the side wall <NUM>. A stepped portion <NUM> having an end surface abutted with the mount surface <NUM> of the base portion <NUM> is formed in an inside part of the side wall <NUM>. A leading end surface <NUM> of the side wall <NUM> is abutted with an outer peripheral edge <NUM> of the thin plate <NUM> provided on the lower surface <NUM> of the base portion <NUM>. The cover portion <NUM>, the base portion <NUM>, and the thin plate <NUM> are fastened in a part where the stepped portion <NUM> of the cover portion <NUM> and the mount surface <NUM> of the base portion <NUM> are abutted by fastening together by bolts, etc. from the outside of the thin plate <NUM>. In such a way, by completely covering the inverter <NUM> and the smoothing capacitor <NUM> by the cover portion <NUM> and the thin plate <NUM> made of a metal material, it is possible to enhance an electromagnetic shielding property of the electric power converter <NUM>. An openable/closable lid portion <NUM> may be provided on the upper wall <NUM> of the cover portion <NUM> so that maintenance can be made to fastening of the conductor portions <NUM> and the conductor portions <NUM> to be described later.

<FIG> is a perspective bottom view of the smoothing capacitor <NUM>.

The capacitor case <NUM> of the smoothing capacitor <NUM> houses the capacitor element <NUM> inside, and the periphery of the capacitor element <NUM> is filled with the filler <NUM>. The periphery of the filler <NUM> is covered by an upper surface <NUM>, a front surface <NUM>, a back surface <NUM>, and side surfaces <NUM> of the capacitor case <NUM>. A bottom surface of the capacitor case <NUM> is open, and the filler <NUM> forms a potting surface <NUM> on a bottom surface of the smoothing capacitor <NUM>.

The capacitor case <NUM> includes brackets <NUM> projecting outward from the front surface <NUM> and the back surface <NUM> and positioning pins <NUM> projecting downward from the bottom surface. The brackets <NUM> are members configured to fasten the smoothing capacitor <NUM> to the housing <NUM>. A hole portion <NUM> through which a bolt, etc. for fastening the smoothing capacitor <NUM> to the base portion <NUM> passes is provided in each of the brackets <NUM>. The positioning pins <NUM> are members configured to determine a horizontal position of the smoothing capacitor <NUM> in the housing <NUM>. The positioning pins <NUM> project to the lower side of the bottom surface respectively from a corner portion <NUM> where an one-side side surface 234b of the capacitor case <NUM> and the front surface <NUM> are connected on the bottom surface of the smoothing capacitor <NUM>, and from a corner portion <NUM> where the one-side side surface 234b of the capacitor case <NUM> and the back surface <NUM> are connected on the bottom surface of the smoothing capacitor <NUM>. By inserting the positioning pins <NUM> into the base portion <NUM>, the horizontal position of the smoothing capacitor <NUM> with respect to the housing <NUM> is determined.

In the present embodiment, the positioning pins <NUM> are respectively provided in the corner portions <NUM>, <NUM> where the one-side side surface 234b of the capacitor case <NUM> is connected to the front surface <NUM> and the back surface <NUM> on the bottom surface of the smoothing capacitor <NUM>. However, the number and the position of the positioning pins <NUM> are not limited to this. For example, the positioning pins <NUM> may be provided in all the four corner portions on the bottom surface of the smoothing capacitor <NUM>.

The plural conductor portions <NUM> and <NUM> connected to the capacitor element <NUM> extend to the outside of the smoothing capacitor <NUM> from the potting surface <NUM>. The conductor portions <NUM>, the conductor portions <NUM>, and the conductor portions <NUM> to be described later are metal bus bars made of, for example, highly-conductive copper, aluminum, etc. The conductor portions <NUM> project to the outside of the smoothing capacitor <NUM> from the vicinity of a one-side side surface 234a of the capacitor case <NUM> on the potting surface <NUM>, and electrically connect the capacitor element <NUM> and the power module <NUM> of the inverter <NUM>. The conductor portions <NUM> project to the outside of the smoothing capacitor <NUM> from the vicinity of the other-side side surface 234b of the capacitor case <NUM> on the potting surface <NUM>, and electrically connect the capacitor element <NUM> and the power source <NUM> outside the electric power converter <NUM> via the conductor portions <NUM>. The conductor portions <NUM> and the conductor portions <NUM> respectively include input conductor portions 20a and conductor portions 30a to which the electric power is inputted from the power source <NUM>, and output conductor portions 20b and conductor portions 30b from which the electric power is outputted to the power source <NUM>. Details of arrangement of the conductor portions will be described later.

<FIG> is a sectional view of the base portion <NUM> of the housing <NUM>, the view showing the base portion <NUM> before the cover portion <NUM> is attached. <FIG> is a sectional view of the electric power converter <NUM>, the view in which the smoothing capacitor <NUM> is attached.

The base portion <NUM> is made of an electrically-insulating resin material, and as shown in <FIG>, and includes a main body portion <NUM> and a bottom plate portion <NUM>. The main body portion <NUM> has an opening <NUM> configured to form the cooling passage <NUM>, joining portions <NUM> configured to join the bottom plate portion <NUM>, and terminal portions <NUM> configured to fasten the conductor portions <NUM> and the conductor portions <NUM>. As shown in <FIG>, the main body portion <NUM> further has holding portions <NUM> configured to hold the smoothing capacitor <NUM> and pin receiving portions <NUM> into which the positioning pins <NUM> configured to position the smoothing capacitor <NUM> are inserted.

The opening <NUM> of the main body portion <NUM> is provided at a point of the base portion <NUM> where the inverter <NUM> is mounted, and an upper surface and a bottom surface are open. The joining portions <NUM> are parts into which projected portions <NUM> of the bottom plate portion <NUM> to be described later are inserted and joined. The joining portions <NUM> are holes whose lower surfaces are open, and provided around the opening <NUM>.

The bottom plate portion <NUM> has a larger outer shape than the opening <NUM> of the main body portion <NUM>, and has the projected portions <NUM> projecting upward from an upper surface of the bottom plate portion <NUM> at positions corresponding to the joining portions <NUM> of the main body portion <NUM>. The projected portions <NUM> and the joining portions <NUM> of the main body portion <NUM> are joined to each other by welding, etc. By joining the main body portion <NUM> and the bottom plate portion <NUM>, a recessed portion <NUM> is formed at a position of the opening <NUM>. The recessed portion <NUM> is a groove configured to form the cooling passage <NUM> through which the cooling water that cools the inverter <NUM> flows. As shown in <FIG>, by covering an upper portion of the recessed portion <NUM> by the substrate <NUM> of the power module <NUM>, the cooling passage <NUM> (first coolant flow passage) enclosed by the main body portion <NUM>, the bottom plate portion <NUM>, and the substrate <NUM> is formed.

As shown in <FIG>, the terminal portions <NUM> of the main body portion <NUM> are provided in parts where the conductor portions <NUM> connected to the smoothing capacitor <NUM> and the conductor portions <NUM> connected to the power source <NUM> are connected, at positions between a point where the smoothing capacitor <NUM> is installed and the side wall <NUM> of the housing <NUM>. The terminal portions <NUM> are integrated with the base portion <NUM> to project upward from the mount surface <NUM> of the base portion <NUM>. The conductor portions <NUM> and the conductor portions <NUM> are fastened on upper surfaces <NUM> of the terminal portions <NUM> by fastening together to the base portion by bolts, etc. In such a way, by integrating the terminal portions <NUM> with the base portion <NUM> that forms the housing <NUM>, it is possible to reduce cost in comparison to a case where the terminal portions <NUM> are provided as separate members.

The holding portions <NUM> of the main body portion <NUM> are parts configured to hold the smoothing capacitor <NUM> and are provided to project upward from the mount surface <NUM> of the base portion <NUM> at positions opposing the brackets <NUM> of the smoothing capacitor <NUM>. The smoothing capacitor <NUM> is fastened to the holding portions <NUM> by bolts, etc. via the hole portions <NUM> of the brackets <NUM>. Thereby, up-down movement of the smoothing capacitor <NUM> with respect to the housing <NUM> is particularly regulated.

The pin receiving portions <NUM> of the main body portion <NUM> are provided to project upward from the mount surface <NUM> of the base portion <NUM> at positions corresponding to the positioning pins <NUM> of the smoothing capacitor <NUM>. By inserting the positioning pins <NUM> into the pin receiving portions <NUM>, the horizontal position of the smoothing capacitor <NUM> with respect to the housing <NUM> is determined.

In order to make positioning of the smoothing capacitor <NUM> easier, it is preferable to respectively provide the positioning pins <NUM> in the capacitor case <NUM> and the pin receiving portions <NUM> in the base portion <NUM> as described above. However, these are not necessarily provided.

A hollow portion <NUM> whose bottom surface is open may be formed in a part of the base portion <NUM> where no cooling passage <NUM> is provided. Thereby, weight of the electric power converter <NUM> is reduced. The number and the shape of the hollow portion <NUM> are not particularly limited. For example, one large hollow portion may be provided or a bottom surface may be closed.

Next, the details of the arrangement of the conductor portions will be described.

As shown in <FIG> and <FIG>, one ends of the conductor portions <NUM> that electrically connect the inverter <NUM> and the smoothing capacitor <NUM> are connected to the capacitor element <NUM> of the smoothing capacitor <NUM> and project downward from the potting surface <NUM> of the smoothing capacitor <NUM>. The other ends of the conductor portions <NUM> are fixed to the power module <NUM> by bolts, etc. at the terminal portion <NUM> provided in the power module <NUM> of the inverter <NUM>. Thereby, the inverter <NUM> and the smoothing capacitor <NUM> are electrically connected by the conductor portions <NUM>.

The conductor portions <NUM> are placed in the vicinity of the base portion <NUM> of the housing <NUM> in the middle of connection between the capacitor element <NUM> of the smoothing capacitor <NUM> and the power module <NUM> of the inverter <NUM>. In such a way, even when the conductor portions <NUM> are arranged at positions in the vicinity of the base portion <NUM>, an insulation property between the conductor portions <NUM> and the housing <NUM> is ensured as the base portion <NUM> is made of an insulating material. Since the conductor portions <NUM> are placed in the vicinity of the base portion <NUM>, heat of the conductor portions <NUM> is also transferred to the base portion <NUM> via a space between the base portion <NUM> and the conductor portions <NUM>. Since the base portion <NUM> includes the cooling passage <NUM>, the base portion <NUM> is also cooled by the cooling water flowing through the cooling passage <NUM>. Therefore, heat exchange is made between the base portion <NUM> cooled by the cooling water and the conductor portions <NUM>, so that the smoothing capacitor <NUM> connected to the conductor portions <NUM> is cooled.

The conductor portions <NUM> and the conductor portions <NUM> are members configured to electrically connect the smoothing capacitor <NUM> and the power source <NUM> outside the housing <NUM>. The conductor portions <NUM> include the input conductor portions 20a and the output conductor portions 20b, and the conductor portions <NUM> include the input conductor portions 30a and the output conductor portions 30b. As shown in <FIG>, one ends of the conductor portions 20a, 20b are connected to the capacitor element <NUM> of the smoothing capacitor <NUM> and project downward from the potting surface <NUM> of the smoothing capacitor <NUM>. The other ends of the conductor portions 20a, 20b are connected to the conductor portions 30a, 30b on the upper surfaces 3171a, 3171b of the terminal portions 317a, 317b projecting upward from the mount surface <NUM> of the base portion <NUM>. The conductor portions 20a, 20b and the conductor portions 30a, 30b are fastened together to the base portion <NUM> by bolts, etc. on the upper surfaces 3171a, 3171b of the terminal portions 317a, 317b.

The conductor portions 20a, 20b are placed in the vicinity of the base portion <NUM> of the housing <NUM> in the middle of connection between the capacitor element <NUM> of the smoothing capacitor <NUM> and the conductor portions 30a, 30b. In such a way, even when the conductor portions 20a, 20b are arranged at positions in the vicinity of the base portion <NUM>, an insulation property between the conductor portions 20a, 20b and the housing <NUM> is ensured as the base portion <NUM> is made of an insulating material. As well as the conductor portions <NUM>, the conductor portions 20a, 20b are placed in the vicinity of the base portion <NUM>. Thus, heat of the conductor portions 20a, 20b is also transferred to the base portion <NUM> via a space between the base portion <NUM> and the conductor portions 20a, 20b. That is, as well as the conductor portions <NUM>, heat exchange is made between the base portion <NUM> cooled by the cooling water and the conductor portions 20a, 20b, so that the smoothing capacitor <NUM> connected to the conductor portions 20a, 20b is cooled.

One ends of the conductor portions 30a, 30b are connected to the conductor portions 20a, 20b on the upper surfaces 3171a, 3171b of the terminal portions 317a, 317b and provided to extend to the outside of the housing <NUM> from the openings 323a, 323b formed in the side wall <NUM> of the housing <NUM>. The other ends of the conductor portions 30a, 30b are connected to the power source <NUM> outside. In such a way, the smoothing capacitor <NUM> and the power source <NUM> are electrically connected via the input conductor portions 20a and conductor portions 30a and the output conductor portions 20b and 30b.

Length of parts of the conductor portions <NUM> and the conductor portions <NUM> in the vicinity of the base portion <NUM> are not particularly limited. However, in order to more increase a cooling effect by the cooling water, the distance of the parts in the vicinity of the base portion <NUM> is preferably as long as possible.

In <FIG>, the six conductor portions <NUM>, the two conductor portions 20a, and the two conductor portions 20b project from the smoothing capacitor <NUM>. However, the number of the conductor portions is not limited to this.

With the electric power converter <NUM> of the first embodiment described above, it is possible to obtain the following effects.

In the electric power converter <NUM>, the housing <NUM> includes the base portion <NUM> made of a resin material, the base portion on which the inverter <NUM> and the smoothing capacitor <NUM> are mounted, and the cover portion <NUM> attached to the base portion <NUM> to cover the inverter <NUM> and the smoothing capacitor <NUM>. The conductor portions <NUM> (first conductor portions) configured to connect the smoothing capacitor <NUM> and the inverter <NUM> are placed in the vicinity of the base portion <NUM> of the housing <NUM> in the middle of connection between the smoothing capacitor <NUM> and the inverter <NUM>. In such a way, by making the base portion <NUM> of an insulating material, the insulation property between the conductor portions <NUM> and the housing <NUM> is ensured, and the conductor portions <NUM> are arranged at the positions in the vicinity of the base portion <NUM>. Therefore, there is no need for placing a separate member such as an insulating member between the conductor portions <NUM> and the housing <NUM>, so that cost can be reduced. In addition, since the conductor portions <NUM> are arranged at the positions in the vicinity of the base portion <NUM>, a space can be saved in comparison to a case where an insulation space distance of the conductor portions <NUM> and the housing <NUM> is increased. That is, it is possible to provide the electric power converter capable of reducing cost and saving a space while ensuring the insulation property between the conductor portions <NUM> connected to the smoothing capacitor <NUM> and the housing <NUM>.

Next, the electric power converter <NUM> includes the conductor portions <NUM>, <NUM> (second conductor portions) configured to connect the smoothing capacitor <NUM> and the power source <NUM> outside the housing <NUM>, and the conductor portions <NUM> are placed in the vicinity of the base portion <NUM> of the housing <NUM> in the middle of connection between the smoothing capacitor <NUM> and the power source <NUM>. Since the base portion <NUM> is made of an insulating material, as well as the conductor portions <NUM>, there is no need for placing a separate member such as an insulating member between the conductor portions <NUM> and the housing <NUM>, so that cost can be reduced. In addition, since the conductor portions <NUM> are arranged at the positions in the vicinity of the base portion <NUM>, a space can be saved in comparison to a case where an insulation space distance of the conductor portions <NUM> and the housing <NUM> is increased. That is, it is possible to provide the electric power converter capable of reducing cost and saving a space while ensuring the insulation property between the conductor portions <NUM> connected to the smoothing capacitor <NUM> and the housing <NUM>.

The base portion <NUM> of the electric power converter <NUM> includes the cooling passage <NUM> (first coolant flow passage) through which the cooling water (coolant) that cools the inverter <NUM> flows. Thereby, the inverter <NUM> is directly cooled and the base portion <NUM> is also cooled by heat exchange between the cooling water and the base portion <NUM>. Meanwhile, since the conductor portions <NUM>, <NUM> are placed in the vicinity of the base portion <NUM>, the heat of the conductor portions <NUM>, <NUM> are also transferred to the base portion <NUM> via the spaces between the base portion <NUM> and the conductor portions <NUM>, <NUM>. Therefore, heat exchange is made between the base portion <NUM> cooled by the cooling water and the conductor portions <NUM>, <NUM>, and it is possible to improve a performance of cooling the smoothing capacitor <NUM> connected to the conductor portions <NUM>, <NUM>. That is, it is possible to provide the electric power converter in which an effect of cooling the smoothing capacitor <NUM> is improved while ensuring the insulation property between the conductor portions <NUM>, <NUM> connected to the smoothing capacitor <NUM> and the housing <NUM>.

With reference to <FIG>, a modified example of the electric power converter <NUM> according to the first embodiment of the present invention will be described.

<FIG> is a schematic sectional view of an electric power converter <NUM> according to the modified example of the first embodiment. As shown in <FIG>, in the present modified example, the conductor portions <NUM> are arranged in contact with the base portion <NUM> of the housing <NUM> in the middle of connection between the capacitor element <NUM> of the smoothing capacitor <NUM> and the power module <NUM> of the inverter <NUM>. In such a way, even when the conductor portions <NUM> are placed in contact with the base portion <NUM>, the insulation property between the conductor portions <NUM> and the housing <NUM> is ensured as the base portion <NUM> is made of an insulating material.

According to the modified example of the first embodiment described above, it is possible to further obtain the following effects.

In the electric power converter <NUM>, the base portion <NUM> of the housing <NUM> is made of an insulating resin material, and the conductor portions <NUM> (first conductor portions) configured to connect the smoothing capacitor <NUM> and the inverter <NUM> are placed in contact with the base portion <NUM> of the housing <NUM> in the middle of connection between the smoothing capacitor <NUM> and the inverter <NUM>. That is, by making the base portion <NUM> of an insulating material, the insulation property between the conductor portions <NUM> and the housing <NUM> is ensured, and the conductor portions <NUM> are arranged in contact with the base portion <NUM>. In such a way, by placing the conductor portions <NUM> in contact with the housing <NUM>, a space between the conductor portions <NUM> and the housing <NUM> is eliminated. Thus, it is possible to save a space more in the electric power converter. That is, it is possible to provide the electric power converter in which a space is saved more while ensuring the insulation property between the conductor portions <NUM> connected to the smoothing capacitor <NUM> and the housing <NUM>.

Since the conductor portions <NUM> are placed in contact with the base portion <NUM> of the housing <NUM>, heat exchange is made between the cooling water flowing through the cooling passage <NUM> (first coolant flow passage) and the conductor portions <NUM> via the base portion <NUM>. That is, heat exchange is made between the cooling water and the conductor portions <NUM> without going via a space between the conductor portions <NUM> and the base portion <NUM>. Therefore, in comparison to a case where the conductor portions <NUM> are placed in no contact with the base portion <NUM> of the housing <NUM>, the cooling effect by the cooling water flowing through the cooling passage <NUM> is more easily transmitted to the conductor portions <NUM>, and it is possible to improve the performance of cooling the smoothing capacitor <NUM> connected to the conductor portions <NUM> more. That is, it is possible to provide the electric power converter in which the performance of cooling the smoothing capacitor <NUM> is improved more while ensuring the insulation property between the housing <NUM> and the conductor portions <NUM>.

In the present embodiment, only the conductor portions <NUM> are placed in contact with the base portion <NUM>. However, both the conductor portions <NUM> and the conductor portions <NUM> may be arranged in contact with the base portion <NUM>, or only the conductor portions <NUM> may be placed in contact with the base portion <NUM> and the conductor portions <NUM> may be placed in the vicinity of the base portion <NUM>.

With reference to <FIG> and <FIG>, an electric power converter <NUM> according to a second embodiment will be described. The same elements as the first embodiment will be given the same reference signs and will not be described.

<FIG> is a schematic sectional view of the electric power converter <NUM> according to the second embodiment. <FIG> is a perspective bottom view of a smoothing capacitor <NUM>. As shown in <FIG> and <FIG>, in the present embodiment, a point that conductor portions <NUM> (third conductor portions) exclusive for cooling are provided is different from the first embodiment and the modified example of the first embodiment.

As shown in <FIG>, the smoothing capacitor <NUM> has a potting surface <NUM> formed by a filler <NUM> on a bottom surface. From the potting surface <NUM>, the conductor portions <NUM> extend to the outside of the capacitor in addition to conductor portions <NUM> and conductor portions <NUM>.

The conductor portions <NUM> are members configured to cool the capacitor, and are made of, for example, highly-conductive copper, aluminum, etc. As shown in <FIG>, one ends of the conductor portions <NUM> are connected to a capacitor element <NUM>, and the other ends are placed in contact with a base portion <NUM>. The conductor portions <NUM> project to the outside of the smoothing capacitor <NUM> from the vicinity of a one-side side surface 234a of a capacitor case <NUM> on the potting surface <NUM>, and are provided to extend to positions where the conductor portions <NUM> are in contact with the base portion <NUM>. At the positions where the conductor portions <NUM> are in contact with the base portion <NUM>, the conductor portions <NUM> are bent and provided to extend toward the inside of the smoothing capacitor <NUM> while in contact with the base portion <NUM>. Thereby, contact surfaces <NUM> where the conductor portions <NUM> and the base portion <NUM> are in contact with each other are formed.

In such a way, the conductor portions <NUM> are placed in contact with the base portion <NUM>. Thus, heat exchange is made between cooling water flowing through a cooling passage <NUM> and the conductor portions <NUM> via the base portion <NUM>, so that the conductor portions <NUM> and the smoothing capacitor <NUM> connected to the conductor portions <NUM> are cooled. That is, by providing the conductor portions <NUM> exclusive for cooling, a cooling effect by the cooling water is transmitted to the conductor portions <NUM> via the base portion <NUM>. Thus, a performance of cooling the smoothing capacitor <NUM> is improved more. Even when the conductor portions <NUM> are arranged at the positions where the conductor portions <NUM> are in contact with the base portion <NUM>, an insulation property between the conductor portions <NUM> and a housing <NUM> is ensured as the base portion <NUM> is made of an insulating material.

The conductor portions <NUM> are bent at the positions where the conductor portions <NUM> are in contact with the base portion <NUM> and the contact surfaces <NUM> are formed between the conductor portions <NUM> and the base portion <NUM>. Thus, a contact area of the conductor portions <NUM> and the base portion <NUM> is increased, and the performance of cooling the smoothing capacitor <NUM> is further improved.

With the electric power converter <NUM> according to the second embodiment described above, it is possible to obtain the following effects.

In the electric power converter <NUM>, the base portion <NUM> of the housing <NUM> is made of an insulating resin material and the conductor portions <NUM> configured to cool the smoothing capacitor <NUM> are provided. The conductor portions <NUM> are connected to the smoothing capacitor <NUM> and have parts in contact with the base portion <NUM> of the housing <NUM>. That is, by making the base portion <NUM> of an insulating material, the insulation property between the conductor portions <NUM> and the housing <NUM> is ensured, and the conductor portions <NUM> are placed in contact with the base portion <NUM>. Thereby, heat exchange is made between the cooling water flowing through the cooling passage <NUM> and the conductor portions <NUM> via the base portion <NUM>. In such a way, the cooling effect by the cooling water flowing through the cooling passage <NUM> is transmitted to the conductor portions <NUM> via the base portion <NUM>. Thus, the performance of cooling the smoothing capacitor <NUM> connected to the conductor portions <NUM> is improved more. Therefore, it is possible to provide the electric power converter in which the effect of cooling the smoothing capacitor <NUM> is improved more while ensuring the insulation property of the housing <NUM> and the conductor portions <NUM>.

In order to enhance the performance of cooling the smoothing capacitor <NUM> more, the conductor portions <NUM> are preferably arranged in contact with the base portion <NUM> as in the present embodiment. However, the present invention is not limited to this but the conductor portions <NUM> may be arranged at positions in the vicinity of the base portion <NUM>.

In the present embodiment, the conductor portions <NUM> are bent toward the inside of the smoothing capacitor <NUM>. However, the conductor portions <NUM> may be bent toward the outside of the smoothing capacitor <NUM>.

In the present embodiment, the conductor portions <NUM> are provided to project to the outside of the smoothing capacitor <NUM> from the vicinity of the one-side side surface 234a of the capacitor case <NUM>. However, the conductor portions <NUM> may be provided to project from the vicinity of the other-side side surface 234b of the capacitor case <NUM>.

In <FIG>, no positioning pins <NUM> are provided in the capacitor case <NUM>. However, positioning pins <NUM> and pin receiving portions <NUM> may be provided to position the smoothing capacitor <NUM> as well as the first embodiment.

With reference to <FIG>, an electric power converter <NUM> according to a modified example of the second embodiment will be described. The same elements as the other embodiment will be given the same reference signs and will not be described.

<FIG> is a schematic sectional view of the electric power converter <NUM> according to the modified example of the second embodiment. As shown in <FIG>, in the present modified example, the conductor portions <NUM> (first conductor portions) and the conductor portions <NUM> (third conductor portions) are not placed in direct contact with the base portion <NUM> but elastic conductive members <NUM> are sandwiched between the conductor portions <NUM> and the conductor portions <NUM>, and the base portion <NUM> of the housing <NUM>.

As shown in <FIG>, the conductor portions <NUM> projecting from the potting surface <NUM> which is formed on the bottom surface of the smoothing capacitor <NUM> are placed in the vicinity of the base portion <NUM> of the housing <NUM> in the middle of connection between the smoothing capacitor <NUM> and the inverter <NUM>. The conductor portions <NUM> projecting from the potting surface <NUM> which is formed on the bottom surface of the smoothing capacitor <NUM> are bent toward the inside of the smoothing capacitor <NUM> at positions where the conductor portions <NUM> are in the vicinity of the base portion <NUM> of the housing <NUM>. As well as the second embodiment, the conductor portions <NUM> may be bent toward the outside of the smoothing capacitor <NUM>.

As shown in <FIG>, the elastic conductive members <NUM> are placed between the conductor portions <NUM>, <NUM> and the base portion <NUM>. The elastic conductive members <NUM> are, for example, highly-conductive grease, adhesive, sheets, etc. and are respectively provided between the conductor portions and the base portion <NUM> in parts where the conductor portions <NUM>, <NUM> are in the vicinity of the base portion <NUM>. Upper surfaces <NUM> of the elastic conductive members <NUM> are in contact with the conductor portions <NUM>, <NUM>, and bottom surfaces <NUM> are in contact with the base portion <NUM>.

In such a way, by placing the highly-conductive elastic conductive members <NUM> between the conductor portions <NUM>, <NUM> and the base portion <NUM>, the elastic conductive members <NUM> perform a function of absorbing dimensional tolerance between the conductor portions <NUM>, <NUM> and the base portion <NUM>. Thereby, in comparison to a case where the conductor portions <NUM>, <NUM> are placed in direct contact with the base portion <NUM>, it is possible to improve thermal conductivity between the conductor portions <NUM>, <NUM> and the base portion <NUM>. That is, a rate of heat exchange made via the base portion <NUM> between the cooling water flowing through the cooling passage <NUM> and the conductor portions <NUM>, <NUM> is improved. Even when the conductor portions <NUM>, <NUM> are placed in contact with the base portion <NUM> of the housing <NUM> via the highly-conductive elastic conductive members <NUM> in such a way, the insulation property between the conductor portions <NUM>, <NUM> and the housing <NUM> is ensured as the base portion <NUM> is made of an insulating material.

According to the modified example of the second embodiment described above, it is possible to further obtain the following effect.

In the electric power converter <NUM>, the base portion <NUM> of the housing <NUM> is made of an insulating resin material, the elastic conductive members <NUM> placed in contact with the base portion <NUM> are provided, and the conductor portions <NUM> (first conductor portions) and the conductor portions <NUM> (third conductor portions) are placed in contact with the elastic conductive members <NUM> in the parts where the conductor portions <NUM>, <NUM> are in the vicinity of the base portion <NUM>. That is, by making the base portion <NUM> of an insulating material, the insulation property between the conductor portions <NUM>, <NUM> and the housing <NUM> is ensured, and the conductor portions <NUM>, <NUM> are placed in contact with the base portion <NUM> via the elastic conductive members <NUM>. In such a way, by providing the elastic conductive members <NUM> in contact with the base portion <NUM> and the conductor portions <NUM>, <NUM> in the parts where the conductor portions <NUM>, <NUM> are placed in the vicinity of the base portion <NUM>, the elastic conductive members <NUM> perform the function of absorbing dimensional tolerance between the conductor portions <NUM>, <NUM> and the base portion <NUM>. Thereby, in comparison to a case where the conductor portions <NUM>, <NUM> are placed in direct contact with the base portion <NUM>, it is possible to improve thermal conductivity between the conductor portions <NUM>, <NUM> and the base portion <NUM>. Therefore, the rate of heat exchange made via the base portion <NUM> between the cooling water flowing through the cooling passage <NUM> and the conductor portions <NUM>, <NUM> is improved, and it is possible to further improve the performance of cooling the smoothing capacitor <NUM>. That is, it is possible to provide the electric power converter in which the performance of cooling the smoothing capacitor <NUM> is further improved while ensuring the insulation property between the housing <NUM> and the conductor portions <NUM>, <NUM>.

In the present embodiment, the elastic conductive members <NUM> are placed between the conductor portions <NUM>, <NUM> and the base portion <NUM>. However, elastic conductive members <NUM> placed in contact with the conductor portions <NUM> and the base portion <NUM> may be provided in parts where the conductor portions <NUM> are placed in the vicinity of the base portion <NUM>.

With reference to <FIG>, an electric power converter <NUM> according to a third embodiment will be described. The same elements as the other embodiments will be given the same reference signs and will not be described.

<FIG> is a schematic sectional view of the electric power converter <NUM> according to the third embodiment. As shown in <FIG>, in the present embodiment, a base portion <NUM> includes a second cooling passage <NUM> (second coolant flow passage) through which cooling water (coolant) flows below elastic conductive members <NUM>.

As shown in <FIG>, a main body portion <NUM> of the base portion <NUM> has a recessed portion <NUM> whose bottom surface is open below a position opposing conductor portions <NUM>, <NUM>, that is, below the elastic conductive members <NUM>. The main body portion <NUM> also has joining portions <NUM> which are holes whose lower surfaces are open around an opening <NUM> and around the recessed portion <NUM>.

A bottom plate portion <NUM> of the base portion <NUM> has an outer shape of such size that the bottom surfaces of both the opening <NUM> of the main body portion <NUM> and the recessed portion <NUM> can be covered, and has projected portions <NUM> projecting upward from an upper surface of the bottom plate portion <NUM> at positions corresponding to the joining portions <NUM>. The projected portions <NUM> and the joining portions <NUM> of the main body portion <NUM> are joined to each other by welding, etc. By joining the main body portion <NUM> and the bottom plate portion <NUM>, a cooling passage <NUM> enclosed by the main body portion <NUM>, the bottom plate portion <NUM>, and a substrate <NUM> of a power module <NUM> is formed at a position of the opening <NUM>. The second cooling passage <NUM> enclosed by the main body portion <NUM> and the bottom plate portion <NUM> is formed at a position of the recessed portion <NUM>.

The cooling passage <NUM> is a flow passage through which the cooling water for cooling a smoothing capacitor <NUM> flows, and is formed below the position opposing the conductor portions <NUM>, <NUM>, that is, below the elastic conductive members <NUM>, and connected to the cooling passage <NUM>. Therefore, the cooling water circulates and flows through the cooling passage <NUM> and the cooling passage <NUM>. In such a way, by providing the second cooling passage <NUM> below the position opposing the conductor portions <NUM>, <NUM>, in comparison to a case where the base portion <NUM> has only the cooling passage <NUM>, a heat transfer path between the conductor portions <NUM>, <NUM> and the cooling water is shortened, and it is possible to further improve a performance of cooling the smoothing capacitor <NUM>. As well as the modified example of the second embodiment, the conductor portions <NUM>, <NUM> are placed in contact with the base portion <NUM> of a housing <NUM> via the highly-conductive elastic conductive members <NUM>. However, as the base portion <NUM> is made of an insulating material, an insulation property between the conductor portions <NUM>, <NUM> and the housing <NUM> is ensured.

Regarding the cooling passage <NUM> and the cooling passage <NUM>, the cooling passage <NUM> may be placed on the upstream side in a case where an inverter <NUM> (power module <NUM>) needs to be cooled more than the smoothing capacitor <NUM>, and the cooling passage <NUM> may be placed on the upstream side in a case where the smoothing capacitor <NUM> needs to be cooled more.

With the electric power converter <NUM> according to the third embodiment described above, it is possible to obtain the following effect.

In the electric power converter <NUM>, the base portion <NUM> of the housing <NUM> is made of an insulating resin material, and the base portion <NUM> includes the cooling passage <NUM> (second coolant flow passage) through which the cooling water (coolant) flows below a part opposing the conductor portions <NUM>, <NUM>, that is, below the elastic conductive members <NUM>. That is, by making the base portion <NUM> of an insulating material, the insulation property between the conductor portions <NUM>, <NUM> and the housing <NUM> is ensured, and the second cooling passage <NUM> is provided below the elastic conductive members <NUM> placed in contact with the conductor portions <NUM>, <NUM>. Thereby, in comparison to a case where the base portion <NUM> has only the cooling passage <NUM> configured to cool the inverter <NUM>, the heat transfer path between the conductor portions <NUM>, <NUM> and the cooling water is shortened, and the performance of cooling the smoothing capacitor <NUM> is further improved. That is, it is possible to further improve the performance of cooling the smoothing capacitor <NUM> while ensuring the insulation property of the housing <NUM> and the conductor portions <NUM>, <NUM>.

In the present embodiment, the elastic conductive members <NUM> are placed between the conductor portions <NUM>, <NUM> and the base portion <NUM>. However, the conductor portions <NUM>, <NUM> may be placed in direct contact with the base portion <NUM> without placing the elastic conductive members <NUM> in-between.

In the present embodiment, the cooling passage <NUM> and the cooling passage <NUM> are connected to each other, and the cooling water circulates between the cooling passage <NUM> and the cooling passage <NUM>. However, the cooling passage <NUM> and the cooling passage <NUM> may be respectively independent and separate flow passages and both the flow passages may not be connected to each other.

In the present embodiment, the cooling passage <NUM> is provided in the part of the base portion <NUM> opposing the conductor portions <NUM>, <NUM>. However, the cooling passage <NUM> may be provided only at a position opposing any one of the conductor portions <NUM> and the conductor portions <NUM>, or the cooling passage <NUM> may be provided in a part opposing the conductor portions <NUM>. A cooling passage <NUM> may be provided in the part of the base portion <NUM> opposing the conductor portions <NUM>, <NUM> and further another cooling passage may be provided in the part opposing the conductor portions <NUM>.

With reference to <FIG>, an electric power converter <NUM> according to a fourth embodiment will be described. The same elements as the other embodiments will be given the same reference signs and will not be described.

<FIG> is a schematic sectional view of the electric power converter <NUM> according to the fourth embodiment. As shown in <FIG>, in the present embodiment, a point that a base portion <NUM> includes a metal member <NUM> is different from the third embodiment.

As shown in <FIG>, the base portion <NUM> includes a cooling passage <NUM> (second coolant flow passage) through which cooling water that cools a smoothing capacitor <NUM> flows and the metal member <NUM> provided at a position opposing the cooling passage <NUM>. The cooling passage <NUM> has a substantially-U-shaped sectional shape in which a recessed portion <NUM> is formed in the center of a section seen from the front side.

The metal member <NUM> is made of a highly-conductive metal material such as copper and aluminum, and provided at the position opposing the cooling passage <NUM> immediately below elastic conductive members <NUM>. The metal member <NUM> has a T shape in the section seen from the front side of the cooling passage <NUM>, and includes an upper portion <NUM> having an upper surface <NUM> placed in contact with the elastic conductive members <NUM> and a projected portion <NUM> projecting toward the recessed portion <NUM> of the cooling passage <NUM>. The metal member <NUM> is integrated with the base portion <NUM> by insert molding, outsert molding by press-fitting, etc..

In such a way, the metal member <NUM> having high thermal conductivity is provided at the position opposing the cooling passage <NUM> to project toward the cooling passage <NUM>. Thus, it is possible to efficiently transfer heat of conductor portions <NUM>, <NUM> connected to the smoothing capacitor <NUM> to the vicinity of the cooling passage <NUM> via the elastic conductive members <NUM> and the metal member <NUM>. The base portion <NUM> made of a resin material is placed between the metal member <NUM> and the cooling passage <NUM>. Thus, an insulation property between the metal member <NUM>, and a casing <NUM> and the cooling water is ensured, so that an insulation property of the conductor portions <NUM>, <NUM> and the casing <NUM> is ensured.

The cooling passage <NUM> is provided in a substantially-U shape in the section seen from the front side. Thus, in comparison to a case where a circular or square cooling passage is provided, a contact surface area of the cooling water and the base portion <NUM> is increased. Thereby, a rate of heat exchange between the cooling water and the base portion <NUM> is improved, and a rate of heat exchange made via the base portion <NUM> between the cooling water and the conductor portions <NUM>, <NUM> is also improved. Therefore, a performance of cooling the smoothing capacitor <NUM> connected to the conductor portions <NUM>, <NUM> is further improved.

With the electric power converter <NUM> according to the fourth embodiment described above, it is possible to obtain the following effects.

In the electric power converter <NUM>, the base portion <NUM> of the casing <NUM> is made of an insulating resin material, the base portion <NUM> includes the metal member <NUM> placed in contact with the elastic conductive members <NUM>, and the metal member <NUM> is provided at the position opposing the cooling passage <NUM>. In such a way, the metal member <NUM> placed in contact with the elastic conductive members <NUM> is provided at the position opposing the cooling passage <NUM>. Thus, it is possible to efficiently transfer heat of the conductor portions <NUM>, <NUM> connected to the smoothing capacitor <NUM> to the vicinity of the cooling passage <NUM> via the elastic conductive members <NUM> and the metal member <NUM>. The base portion <NUM> made of a resin material is placed between the metal member <NUM> and the cooling passage <NUM>. Thus, the insulation property between the metal member <NUM>, and the casing <NUM> and the cooling water is ensured, so that the insulation property of the conductor portions <NUM>, <NUM> and the casing <NUM> is ensured. Therefore, it is possible to further improve efficiency of cooling the smoothing capacitor <NUM> while ensuring the insulation property between the conductor portions <NUM>, <NUM> and the casing <NUM>.

In the electric power converter <NUM> according to the present embodiment, the metal member <NUM> placed in contact with the elastic conductive members <NUM> also functions as a thermal mass member configured to store heat of the conductor portions <NUM>, <NUM>. Therefore, thermal capacity of the base portion <NUM> is increased by the metal member <NUM>. Thus, it is possible to suppress and lower a temperature increase of the smoothing capacitor <NUM> connected to the conductor portions <NUM>, <NUM>, so that a transient heat performance of the smoothing capacitor <NUM> is improved.

In the present embodiment, the metal member <NUM> is provided immediately below the elastic conductive members <NUM> placed in contact with the conductor portions <NUM>, <NUM>. However, the elastic conductive members <NUM>, the metal member <NUM> placed in contact with the elastic conductive members <NUM>, and the cooling passage <NUM> may be provided below conductor portions <NUM>.

In order to increase the contact surface area of the cooling water and the base portion <NUM>, it is preferable to form the section of the cooling passage <NUM> in a substantially U shape and to form the section of the metal member <NUM> in a T shape to bring the metal member <NUM> closer to the cooling water. However, the shapes of the cooling passage <NUM> and the metal member <NUM> are not necessarily limited to this. As long as the metal member <NUM> is in contact with the elastic conductive members <NUM> and the base portion <NUM> is placed between the metal member <NUM> and the cooling passage <NUM>, the cooling passage <NUM> and the metal member <NUM> may be formed in any shapes.

With reference to <FIG> and <FIG>, a modified example of the electric power converter <NUM> according to the fourth embodiment will be described. The same elements as the other embodiments will be given the same reference signs and will not be described.

<FIG> is a schematic sectional view of an electric power converter <NUM> according to the modified example of the fourth embodiment. <FIG> is a perspective bottom view of a smoothing capacitor <NUM>. As shown in <FIG> and <FIG>, in the present modified example, a base portion <NUM> has projecting portions <NUM> configured to position the smoothing capacitor <NUM>, and holes <NUM>, <NUM> (positioning holes) into which the projecting portions <NUM> are inserted are formed in conductor portions <NUM>, <NUM>.

As shown in <FIG>, the base portion <NUM> has the projecting portions <NUM> projecting from a surface (mount surface <NUM>) on the side where an inverter <NUM> and the smoothing capacitor <NUM> are mounted at positions corresponding to the holes <NUM>, <NUM> of the conductor portions <NUM>, <NUM> to be described later. The projecting portions <NUM> are integrated with the base portion <NUM> and inserted into the holes <NUM>, <NUM> of the conductor portions <NUM>, <NUM>.

As shown in <FIG> and <FIG>, the conductor portions <NUM>, <NUM> projecting downward from a potting surface <NUM> of the smoothing capacitor <NUM> includes the holes <NUM>, <NUM> into which the projecting portions <NUM> of the base portion <NUM> are respectively inserted at points in the vicinity of the base portion <NUM>.

The holes <NUM>, <NUM> are provided in the conductor portion <NUM> and the conductor portion <NUM> arranged to oppose each other among the plural conductor portions <NUM>, <NUM>. A center point of the hole <NUM> of the conductor portion <NUM> and a center point of the hole <NUM> of the conductor portion <NUM> opposing the conductor portion <NUM> are arranged on a straight line parallel to a front surface <NUM> and a back surface <NUM> of the smoothing capacitor <NUM>. By inserting the projecting portions <NUM> of the base portion <NUM> into the holes <NUM>, <NUM>, the smoothing capacitor <NUM> is positioned and the conductor portions <NUM>, <NUM> are also positioned.

From the viewpoint to ensure stability of positioning of the smoothing capacitor <NUM>, the holes <NUM>, <NUM> are preferably provided in the conductor portions <NUM> and <NUM> arranged to oppose each other. However, the present invention is not limited to this. For example, the holes <NUM>, <NUM> may be provided in the conductor portions not opposing each other, or positioning holes may be provided in conductor portions <NUM>. Further, in the present embodiment, the one hole <NUM> and the one hole <NUM> are provided respectively in the conductor portion <NUM> and the conductor portion <NUM>. However, the number of the conductor portions in which the holes <NUM>, <NUM> are provided is not limited to this but, for example, positioning holes may be provided in all the conductor portions.

According to the modified example of the fourth embodiment described above, it is possible to further obtain the following effect.

In the electric power converter <NUM>, the base portion <NUM> of a housing <NUM> has the projecting portions <NUM> projecting from the surface (mount surface <NUM>) on the side where the inverter <NUM> and the smoothing capacitor <NUM> are mounted, and the holes (positioning holes) <NUM>, <NUM> into which the projecting portions <NUM> are inserted are provided in the conductor portions <NUM>, <NUM>. By inserting the projecting portions <NUM> of the base portion <NUM> into the holes <NUM>, <NUM> of the conductor portions <NUM>, <NUM>, the smoothing capacitor <NUM> is positioned and the conductor portions <NUM>, <NUM> are also positioned. In such a way, the conductor portions <NUM>, <NUM> are directly positioned. Thus, precision of positioning the conductor portions <NUM>, <NUM> with respect to terminal portions <NUM>, <NUM> is improved, so that connection quality of the conductor portions at the terminal portions <NUM>, <NUM> is improved.

With reference to <FIG> and <FIG>, an electric power converter <NUM> according to a fifth embodiment will be described. The same elements as the other embodiments will be given the same reference signs and will not be described.

<FIG> is a schematic sectional view of the electric power converter <NUM> according to the fifth embodiment. <FIG> is a perspective bottom view of a smoothing capacitor <NUM>. As shown in <FIG> and <FIG>, in the present embodiment, a point that conductor portions 40A (third conductor portions) configured to cool the smoothing capacitor <NUM> project from a potting surface <NUM> of the smoothing capacitor <NUM> and are inserted into a base portion <NUM> at positions opposing a cooling passage <NUM> is different from the other embodiments.

As shown in <FIG>, the base portion <NUM> has a metal member 6A having high thermal conductivity, the cooling passage <NUM> formed in a substantially U shape in a section seen from the front side, and a groove <NUM> into which the conductor portions 40A configured to cool the smoothing capacitor <NUM> are inserted.

The cooling passage <NUM> has a substantially-U-shaped sectional shape in which a recessed portion <NUM> is formed in the center of the section seen from the front side as well as the fourth embodiment.

The metal member 6A is provided at a position opposing the cooling passage <NUM> immediately below elastic conductive members <NUM>, and has a L shape in a section seen from the front side of the cooling passage <NUM>. The metal member 6A includes an upper portion 61A having an upper surface 611A placed in contact with the elastic conductive members <NUM> and a projected portion 62A projecting toward the recessed portion <NUM> of the cooling passage <NUM>. The projected portion 62A is provided to extend to the vicinity of the cooling passage <NUM>, and transfers heat of the smoothing capacitor <NUM> transmitted to the metal member 6A via conductor portions <NUM> and the elastic conductive members <NUM> to the vicinity of cooling water flowing through the cooling passage <NUM>. The base portion <NUM> made of a resin material is placed between the metal member 6A and the cooling passage <NUM>. Thus, an insulation property between the metal member 6A, and a housing <NUM> and the cooling water is ensured, so that an insulation property of the conductor portions <NUM> and the housing <NUM> is ensured.

The groove <NUM> formed in the base portion is a groove into which the conductor portions 40A configured to cool the smoothing capacitor <NUM> are inserted, and is formed to the vicinity of the cooling passage <NUM> toward the recessed portion <NUM> of the cooling passage <NUM>.

The conductor portions 40A are members configured to cool the capacitor, and one ends are connected to a capacitor element <NUM> of the smoothing capacitor <NUM> and project downward to the outside of the smoothing capacitor <NUM> from the vicinity of a one-side side surface 234a of a capacitor case <NUM> on the potting surface <NUM> of the smoothing capacitor <NUM>. The other ends of the conductor portions 40A are inserted into the groove <NUM> of the base portion <NUM> by light press-fitting, etc. As shown in <FIG> and <FIG>, the conductor portions 40A are not bent but project from the potting surface <NUM> of the smoothing capacitor <NUM> and is provided to extend to the vicinity of the cooling passage <NUM>. Thereby, heat of the smoothing capacitor <NUM> is transferred to the vicinity of the cooling water flowing through the cooling passage <NUM> by the conductor portions 40A. Since the base portion <NUM> is made of an insulating resin material, an insulation property of the conductor portions 40A inserted into the base portion <NUM> and the housing <NUM> is ensured. By inserting the conductor portions 40A into the base portion <NUM>, it is possible to position the smoothing capacitor <NUM> and to position conductor portions <NUM>, <NUM> with respect to terminal portions <NUM>, <NUM>.

With the electric power converter <NUM> according to the fifth embodiment described above, it is possible to obtain the following effects.

In the electric power converter <NUM>, the base portion <NUM> of the housing <NUM> is made of an insulating resin material, and the conductor portions 40A (third conductor portions) whose one ends are connected to the smoothing capacitor <NUM> are inserted into the base portion <NUM> at positions opposing the cooling passage <NUM>. Thereby, heat of the smoothing capacitor <NUM> is transferred to the vicinity of the cooling water flowing through the cooling passage <NUM> by the conductor portions 40A. Meanwhile, since the base portion <NUM> is made of an insulating resin material, the insulation property of the conductor portions 40A inserted into the base portion <NUM> and the housing <NUM> is ensured. Therefore, it is possible to further improve a performance of cooling the smoothing capacitor <NUM> while ensuring the insulation property between the conductor portions 40A and the housing <NUM>.

By inserting the conductor portions 40A into the base portion <NUM>, it is possible to position the smoothing capacitor <NUM> and to position the conductor portions <NUM>, <NUM> with respect to the terminal portions <NUM>, <NUM>. In such a way, by making positioning not with positioning pins <NUM> of the capacitor case <NUM> but with the conductor portions 40A, precision of positioning the conductor portions <NUM>, <NUM> with respect to the terminal portions <NUM>, <NUM> is improved, so that connection quality of the conductor portions at the terminal portions <NUM>, <NUM> is stabilized.

In the present embodiment, the section of the metal member 6A is formed in an L shape and the section of the cooling passage <NUM> is formed in a substantially U shape. However, the shapes of the metal member 6A and the cooling passage <NUM> are not limited to this. As long as one ends of the conductor portions 40A and the metal member 6A are positioned in the vicinity of the cooling passage <NUM>, the metal member 6A and the cooling passage <NUM> may be formed in any shapes.

<FIG> is a schematic sectional view of the electric power converter <NUM> according to the sixth embodiment. <FIG> is a perspective sectional view of the electric power converter <NUM> showing an outer appearance of a smoothing capacitor <NUM>. As shown in <FIG> and <FIG>, in the present embodiment, a point that an elastic member <NUM> is sandwiched between an upper surface <NUM> of the smoothing capacitor <NUM> and a cover portion <NUM> of a housing <NUM>, and a point that the smoothing capacitor <NUM> and the housing <NUM> are not fastened by bolts, etc. are different from the other embodiments.

As shown in <FIG>, the elastic member <NUM> is sandwiched between the upper surface <NUM> of the smoothing capacitor <NUM> (capacitor case <NUM>) and an upper portion <NUM> of the cover portion <NUM> of the housing <NUM>. The elastic member <NUM> is made of an elastic material having higher thermal conductivity than the capacitor case <NUM>, and a lower surface <NUM> is placed in contact with the upper surface <NUM> of the smoothing capacitor <NUM> and an upper surface <NUM> is placed in contact with an inside surface of the upper portion <NUM> of the cover portion <NUM>. In such a way, the upper surface <NUM> of the smoothing capacitor <NUM> is placed in contact with the cover portion <NUM> of the housing <NUM> via the elastic member <NUM>. Thus, up-down movement of the smoothing capacitor <NUM> is regulated. In such a way, the up-down movement of the smoothing capacitor <NUM> is regulated by the elastic member <NUM>. Thus, in the present embodiment, as shown in <FIG>, brackets <NUM> of the smoothing capacitor <NUM> and holding portions <NUM> of a base portion <NUM> are not fastened by bolts, etc..

The elastic member <NUM> may be a conductive member or an insulating member as long as the elastic member <NUM> is an elastic member having high thermal conductivity.

With the electric power converter <NUM> according to the sixth embodiment described above, it is possible to obtain the following effects.

In the electric power converter <NUM>, the upper surface <NUM> of the smoothing capacitor <NUM> is placed in contact with the cover portion <NUM> of the housing <NUM> via the elastic member <NUM>. Thereby, the up-down movement of the smoothing capacitor <NUM> is regulated. Thus, there is no need for fastening the capacitor case <NUM> of the smoothing capacitor <NUM> and the base portion <NUM> of the housing <NUM> by bolts, etc. Therefore, it is possible to shorten takt time at the time of manufacture.

The elastic member <NUM> placed between the smoothing capacitor <NUM> and the cover portion <NUM> of the housing <NUM> is made of an elastic material having higher thermal conductivity than the capacitor case <NUM>. Therefore, it is possible to transfer heat of the smoothing capacitor <NUM> from the elastic member <NUM> to the cover portion <NUM> made of a metal material. Thus, it is possible to suppress a temperature increase of the smoothing capacitor <NUM>.

In any of the embodiments, the electric power converter <NUM> is not necessarily disposed with the base portion <NUM> of the housing <NUM> being arranged on the lower side but may be arranged freely in terms of the direction according to layout of a vehicle in which the electric power converter <NUM> is disposed. For example, as shown in <FIG>, the electric power converter <NUM> shown in <FIG>, etc. may be installed in an upside-down state so that the base portion <NUM> is placed on the upper side and the cover portion <NUM> is placed on the lower side. In addition, the electric power converter <NUM> may be installed while being tilted.

Claim 1:
An electric power converter (<NUM>),
comprising:
- an inverter (<NUM>) which comprises plural electric parts;
- a smoothing capacitor (<NUM>) configured to smooth electric power;
- a first conductor portion (<NUM>) configured to connect the smoothing capacitor (<NUM>) and the inverter (<NUM>), and
- a housing (<NUM>) configured to house the inverter (<NUM>), the smoothing capacitor (<NUM>) and the first conductor portion (<NUM>);
wherein:
- the housing (<NUM>) comprises a base portion (<NUM>) having a mount surface (<NUM>) on which the inverter (<NUM>) and the smoothing capacitor (<NUM>) are mounted,
- the base portion (<NUM>) is made of an insulating resin material,
- the housing (<NUM>) comprises a cover portion (<NUM>) made of metal material attached to the base portion (<NUM>) to cover the inverter (<NUM>), the smoothing capacitor (<NUM>) and the first conductor portion (<NUM>), and
- the housing (<NUM>) comprises a metal thin plate (<NUM>) formed on a lower surface (<NUM>) of the base portion (<NUM>) opposite the mount surface (<NUM>),
- the metal thin plate (<NUM>) is larger than an outer shape of the lower surface (<NUM>) of the base portion (<NUM>) and functions as a bottom plate of the cover portion (<NUM>),
- a stepped portion (<NUM>) having an end surface abutted with the mount surface (<NUM>) of the base portion (<NUM>) is formed in an inside part of the side wall (<NUM>) of the cover portion (<NUM>) and a leading end surface (<NUM>) of the side wall (<NUM>) is abutted with an outer peripheral edge (<NUM>) of the thin plate (<NUM>),
- the first conductor portion (<NUM>) is placed in the vicinity of or in contact with the mount surface (<NUM>) of the base portion (<NUM>) of the housing (<NUM>) in the middle of connection between the smoothing capacitor (<NUM>) and the inverter (<NUM>), and
- the base portion (<NUM>) comprises a first coolant flow passage (<NUM>) through which a coolant that cools the inverter (<NUM>) can flow which is formed below a part where the inverter (<NUM>) is mounted.