JP2016100941A - Power conversion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power conversion apparatus capable of reducing size of an entire apparatus including a case while positioning a power module.SOLUTION: In a power conversion apparatus 1, a case 10 which houses a power module 70 serving a power conversion function of converting power to be supplied to an electric motor includes a fixing portion 32 fixed to a heat sink 60 which cools the power module 70 and fixes the case 10. The fixing portion 32 positions the power module 70 with respect to the case 10.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a power conversion device, and more particularly to a power conversion device that can be suitably applied to a vehicle that is a hybrid vehicle.

  In recent years, in vehicles such as four-wheeled vehicles, hybrid vehicles using an engine that is an internal combustion engine and an electric motor in cooperation with a drive system have become widespread.

  In such a hybrid vehicle, a power conversion device is used as one of the components of an electronic control device that operates an engine and an electric motor in cooperation. Such a power conversion device includes a power module including a plurality of semiconductor elements for appropriately converting a direct current and an alternating current into power.

  Since a power converter provided with such a power module is mounted on a vehicle such as an automobile, it is necessary to reliably position and fix the power module in the case of the power converter.

  Under such circumstances, Patent Document 1 relates to a motor control device and an assembly method thereof, and a power semiconductor module that is in close contact with a heat sink is connected to a substrate, and an insulating spacer is interposed between the heat sink and the substrate. The power semiconductor module is disposed in the provided engaging portion, and the edge of the engaging portion is configured to enter under the terminal protruding from the side of the power semiconductor module, between the terminal of the power semiconductor module and the heat sink. A configuration intended to improve insulation by blocking the space is disclosed.

JP 2010-178625 A

  However, according to the study of the present inventor, the configuration of Patent Document 1 employs a configuration in which an insulating spacer is interposed between the heat sink and the substrate. When attaching the spacer, a spacer for positioning and fixing the power module will be separately provided. However, the fixing part for fixing the spacer to the heat sink is separated from the power module positioning part in the spacer. Therefore, the size of the spacer is increased, and as a result, the size of the case for accommodating the power module is increased, and the size of the entire apparatus is also increased, so there is room for improvement.

  The present invention has been made through the above-described studies, and an object of the present invention is to provide a power conversion device that can reduce the size of the entire device including the case while positioning the power module.

  In order to achieve the above object, the present invention provides a power module exhibiting a power conversion function for converting the power supplied to the electric motor, a case for housing the power module, the power module is cooled, and the case is fixed. In the power conversion device including the heat sink, the case includes a fixing portion that fixes the case to the heat sink, and the fixing portion positions the power module with respect to the case. Let's say that.

  Further, in addition to the first aspect, the present invention provides the fixing unit at least at a position facing the power module or a diagonal position of the power module so as to sandwich and contact the power module. The arrangement of two or more is the second aspect.

  Moreover, in addition to the 1st or 2nd aspect, this invention makes it the 3rd aspect to stand up from the bottom wall of the said case in the aspect which the said fixing | fixed part connected to the side wall of the said case.

  In addition to any one of the first to third aspects, the present invention has a flat portion on a part of the outer peripheral wall of the fixed portion so that the fixed portion is in surface contact with the power module. Is the fourth aspect.

  According to the present invention, in addition to any one of the first to fourth aspects, the fixing portion has a taper portion having an inclined surface that retreats as the portion above the power module moves upward. The fifth aspect is assumed.

  According to a sixth aspect of the present invention, in addition to the fifth aspect, in addition to the fifth aspect, the fixing portion further includes a retaining fixing portion in which a lower end portion of the tapered portion protrudes toward the power module. To do.

  According to the power conversion device according to the first aspect of the present invention described above, the case that houses the power module includes the fixing portion that is fixed to the heat sink, and the fixing portion positions the power module with respect to the case. Therefore, the size of the entire apparatus including the case can be reduced while positioning the power module. In particular, by adopting a fixed part that integrates positioning ribs and fixed bosses, the clearance between the ribs and bosses can be eliminated, allowing the power module to be positioned while reducing the size of the main case. The amount of material constituting the main case can be reduced while reducing the size of the entire device, and the weight and cost of the entire device can be reduced.

  Further, according to the power conversion device of the second aspect of the present invention, at least the fixed portion is located at a position facing the power module or a diagonal position of the power module so as to sandwich and contact the power module. Since two or more are provided, the power module can be positioned and fixed while setting the minimum necessary fixing portion with a high degree of freedom.

  Moreover, according to the power converter device concerning the 3rd aspect of this invention, since a fixing | fixed part is standing up from the bottom wall of a case in the aspect connected to the side wall of a case, between a fixing | fixed part and a case The support strength and support rigidity of the fixing portion can be increased while eliminating the clearance between them, and the size of the entire apparatus can be reduced, and the power module can be reliably positioned and fixed.

  Moreover, according to the power converter device concerning the 4th aspect of this invention, since a fixing | fixed part has a plane part in a part of outer peripheral wall of a fixing | fixed part so that a surface contact may be carried out, a positioning is performed. A large contact area as a fixing portion can be secured, and the power module can be firmly fixed.

  Moreover, according to the power converter device of the fifth aspect of the present invention, the fixing portion has a tapered portion that has an inclined surface that retreats as the portion above the power module rises upward. Since the power module can be easily guided into the fixed portion when the power module is assembled to the power module, the assemblability of the power module can be improved.

  Further, according to the power conversion device of the sixth aspect of the present invention, the fixing part further includes a retaining fixing part in which the lower end part of the taper part protrudes toward the power module, and thus the case. At the time of assembling the power module, the power module can be temporarily fixed to the case before the main fixing by fastening and fixing, and the assembling property of the power module can be further improved.

FIG. 1 is a perspective view showing a configuration of a power conversion device according to an embodiment of the present invention. FIG. 2 is a top view showing the power conversion apparatus according to the present embodiment with the upper case removed. FIG. 3 is a cross-sectional view taken along the line AA of FIG. FIG. 4A is a partially enlarged view of FIG. 2, and FIG. 4B is a partially enlarged view showing a modification of the power conversion device according to the present embodiment. This corresponds to 4 (a).

  Hereinafter, the power conversion device according to the embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4 as appropriate. In the figure, the x-axis, y-axis, and z-axis constitute a three-axis orthogonal coordinate system, the z-axis direction corresponds to the vertical direction, and the xz plane is the horizontal plane.

  FIG. 1 is a perspective view illustrating a configuration of a power conversion device according to the present embodiment. FIG. 2 is a top view showing the power conversion apparatus according to the present embodiment with the upper case removed. FIG. 3 is a cross-sectional view taken along the line AA of FIG. FIG. 4A is a partially enlarged view of FIG. 2, and FIG. 4B is a partially enlarged view showing a modification of the power conversion device according to the present embodiment. This corresponds to 4 (a).

  As shown in FIG. 1 to FIG. 4A, the power conversion device 1 is fixedly mounted on a lower case 10 that is a main case and an upper portion of the lower case 10 via a fitting structure (not shown). The upper case 40 that closes the upper portion of the power conversion device 1, the heat sink 60 that is disposed at the lower portion of the lower case 10, and that is attached to the lower case 10 via a fastening member (not shown), the lower case 10, and the upper case 40 are provided. And a power module 70 housed in an internal housing space that is defined in cooperation, and is mounted on a vehicle such as a hybrid vehicle (not shown). The power conversion device 1 is typically mounted on a vehicle and is not shown in the figure, but a direct current supplied from a battery as a secondary battery to a driving electric motor is converted into an alternating current (three-phase current). It has a DC (Direct Current) / AC (Alternate Current) conversion function for conversion. In addition, the power converter device 1 may have an AC / DC conversion function for converting an alternating current supplied to the battery from the electric motor or a regenerative mechanism (not shown) into a direct current as necessary.

  Both the lower case 10 and the upper case 40 are typically molded products made of non-conductive resin (synthetic resin), and the heat sink 60 is typically a cast product made of metal such as an aluminum material. is there. In addition to the power module 70 and the output bus bar 100, the internal housing space defined by the cooperation of the lower case 10 and the upper case 40 accommodates a circuit board, a current sensor, etc. The

  Specifically, the lower case 10 mainly includes a side peripheral wall 12 that circulates around a vertical axis on a plane parallel to the xy plane, and a bottom wall 13 that closes the bottom of the side peripheral wall 12.

  A part of the bottom wall 13 is provided with a plurality of columnar fixed bosses 32 protruding upward and an opening 19 that opens the interior of the lower case 10. The plurality of fixed boss portions 32 are typically disposed at the four corners of the bottom wall 13 that is rectangular in a top view so as to surround and abut the power module 70, and the bottom wall 10 is formed when the lower case 10 is molded. 13 is integrally molded. From the viewpoint of positioning the power module 70 with certainty, the plurality of fixed boss portions 32 correspond to the module case 72 of the power module 70 that is typically rectangular in top view so that the module case 72 abuts at the four corners. It is preferable that they are arranged. However, from the viewpoint of simplifying the configuration, the plurality of fixed boss portions 32 are provided on the module case 72 on both the positive side of the y-axis of the module case 72 and the negative side of the y-axis of the power module 70. It is sufficient that at least two or more of the module cases 72 are disposed at positions facing each other across the module case 72 or diagonal positions of the module case 72 so as to be sandwiched. The plurality of fixed boss portions 32 are preferably connected to a part of the side peripheral wall 12 adjacent to each other from the viewpoint of enhancing their strength and rigidity. Each of the plurality of fixed boss portions 32 is fitted with a collar 36 made of metal or the like. A fastening member 38 is inserted through each of the collars 36, and the lower case 10 is fastened and fixed to the heat sink 60 via each fastening member 38. In the opening 19, the bottom of the power module 70 is exposed to the outside from the internal housing space defined by the lower case 10 and the upper case 40 in cooperation. Note that the shape of the plurality of fixed boss portions 32 is not limited to a columnar shape, and may be another columnar shape such as a prismatic shape. Further, the number of the plurality of fixed boss portions 32 is not limited to four, and may be two or five or more.

  A part of the side peripheral wall 12 is provided with a configuration in which three outer terminal blocks 20 each projecting in the positive direction of the x-axis are juxtaposed in the direction of the y-axis. Each of the outer terminal blocks 20 is typically formed integrally with the side peripheral wall 12 when the lower case 10 is formed. The outer end portions of the corresponding output bus bars 100 are respectively placed on the upper surfaces of the outer terminal blocks 20, and the outer end portions of the output bus bars 100 are not shown in the drawings, but via the fastening members, Fastened together with the end of the bus bar on the electric motor side. The side peripheral wall 12 is formed with notches 28 and 30 that are recessed downward from the upper end thereof. The notches 28 are provided corresponding to the three external terminal blocks 20 arranged side by side, and the corresponding output bus bars 100 are formed outside the internal housing space in which the lower case 10 and the upper case 40 define the cooperation. To each of them. Instead of each notch 28, a through-hole penetrating the side peripheral wall 12 may be provided.

  The upper case 40 mainly includes a side peripheral wall 42 that circulates around a vertical axis on a plane parallel to the xy plane, and an upper wall 43 that closes the upper portion thereof.

  A part of the side peripheral wall 42 is formed with notches 44 and 46 that are recessed upward from the lower end thereof. The cutout portions 44 are provided corresponding to the cutout portions 28 of the lower case 10 and extend the corresponding output bus bars 100. However, the notch portion 44 is provided when the corresponding output bus bar 100 is extended only by the notch portion 28 of the lower case 10 or when a through hole penetrating the side peripheral wall 12 is provided instead of the notch portion 28. Is omitted. The notch portion 46 is provided corresponding to the notch portion 30 of the lower case 10, and in cooperation with the notch portion 30, both are omitted from illustration, but an electric control unit ECU (Electronic Control Unit) is electrically connected. A receiving portion for receiving an input / output signal connector to be connected.

  A part of the upper wall 43 forms a protruding wall 47 whose shape changes so as to protrude upward. In the lower part of the protruding wall 47, although not shown in the drawing, high-profile parts such as a smoothing capacitor mounted on the upper surface of the circuit board are arranged.

  The heat sink 60 mainly includes a rectangular main body 62 and a plurality of fins 64 that protrude downward from the lower surface of the main body 62.

  The power module 70 is typically a molded product made of a plurality of power semiconductor elements for power conversion such as an IGBT (Insulated Gate Bipolar Transistor) (not shown) and a non-conductive resin (synthetic resin). A module case 72 containing a plurality of power semiconductor elements, a signal pin 78 extending upward from the module case 72 and electrically connected to a circuit board (not shown), and one end having a plurality of power semiconductor elements And a power module-side bus bar (not shown) that is typically made of a conductive plate-like member that extends from the module case 72 and extends at the other end.

  The bottom of the module case 72 is opened toward the upper surface of the heat sink 60. The plurality of power semiconductor elements are attached to the module case 72 and abut on the upper surface of the heat sink 60 through the opened bottom of the module case 72 and the opening 19 of the lower case 10. Between the plurality of power semiconductor elements and the upper surface of the heat sink 60, the heat conductivity typically equal to or higher than that of the heat sink 60 is exhibited in order to improve the heat conductivity at the bottom of the plurality of power semiconductor elements. May be provided with a metal heat spreader 76. A plurality of collars 73 for fastening the module case 72 to the heat sink 60 via fastening members (not shown) are provided on the remaining portion other than the opened bottom portion of the module case 72 and the extended portion of the power module side bus bar. Provided. The module case 72 may have a structure in which the bottom thereof is not opened as necessary. In such a case, a plurality of power semiconductor elements are connected to the heat sink 60 via the module case 72. Thermally contacts the top surface.

  Here, in particular, as shown in FIGS. 2 to 4A, a part of the outer wall surface of the module case 72 and a part of the outer wall surfaces of the plurality of fixed boss portions 32 of the lower case 10 corresponding thereto are , Are in contact with each other. In this way, the portions of the outer wall surfaces of the plurality of fixed boss portions 32 that abut against the outer wall surface of the module case 72 each define a positioning portion 33. In each positioning portion 33, a part of the outer wall surface of the module case 72 and a part of the outer wall surfaces of the plurality of fixed boss portions 32 of the lower case 10 corresponding thereto are typically point-contacts in the cross section. However, line contact is made in the longitudinal section. With these positioning portions 33, the power module 70 is positioned in the y-axis direction with respect to the lower case 10, and in these positioning portions 33, a part of the outer wall surface of the module case 72 and the corresponding lower case The power module 70 is also positioned in the x-axis direction and the vertical direction with respect to the lower case 10 by adjusting the static friction force and the pressing force with some of the outer wall surfaces of the plurality of fixed boss portions 32 of the ten. The

  In particular, as shown in FIG. 4A, from the viewpoint of smoothly and reliably guiding the power module 70 between the plurality of fixed boss portions 32 of the lower case 10 and smoothly inserting the power module 70, the plurality of fixed boss portions 32. A plurality of fixed boss portions, each of which has a tapered portion 35 set to an inclined surface that retreats in the negative direction of the y-axis as the upper portion of the outer wall surface of the module case 72 is upward from the position of the upper wall surface of the module case 72 It is preferable to form each of 32. Furthermore, from the viewpoint of ensuring the vertical positioning of the power module 70 with respect to the lower case 10, the lower end portion of the portion that is the tapered portion 35 on the module case 72 side on the outer wall surface of the plurality of fixed boss portions 32. Are projecting toward the upper wall surface of the module case 72, and a locking portion 34 for locking and fixing the part of the upper wall surface of the module case 72 correspondingly is fixed to a plurality of fixing boss portions. 32 are preferably provided.

  In the configuration of the plurality of fixed boss portions 32 of the lower case 10 shown in FIG. 4A, in each positioning portion 33, a part of the outer wall surface of the module case 72 and the corresponding plurality of fixed bosses of the lower case 10 are provided. A part of the outer wall surface of the portion 32 is point-contacted in the cross-section and line-contacted in the vertical cross-section, but the contact area of the contact area is increased to reduce the lower case 10. The positionability of the power module 70 may be improved.

  For example, in particular, as shown in FIG. 4B, some of the outer wall surfaces of the plurality of fixed boss portions 32 of the lower case 10 corresponding to the outer wall surface of the module case 72 are shaped on the outer wall surface of the module case 72. When the matching surface, for example, the outer wall surface of the module case 72 is a plane parallel to the xz plane, some of the outer wall surfaces of the plurality of fixed boss portions 32 are set to a plane parallel to the xz plane. May be. Thereby, in each positioning part 33 ', the contact area of the contact region where a part of the outer wall surface of the module case 72 and a part of the outer wall surfaces of the plurality of fixed boss parts 32 of the lower case 10 corresponding thereto contact each other. And the positioning of the power module 70 with respect to the lower case 10 is improved.

  The output bus bar 100 is typically an electrical wiring provided in a manner arranged in parallel in the y-axis direction corresponding to the U-phase, V-phase, and W-phase of the three-phase current. It consists of a single metal plate-like member that is horizontally arranged while being bent in the vertical direction so that the width direction is the y-axis direction. The output bus bars 100 each extend between the inner and outer ends in the x-axis direction, the inner ends are electrically connected to the power module 70, and the outer ends are the lower case 10 and It extends to the outside of the upper case 40 and reaches the outer terminal block 20.

  As is clear from the above description, in the power conversion device 1 in the present embodiment, the case 10 that houses the power module 70 includes the fixing portion 32 that is fixed to the heat sink 60, and the fixing portion 32 is the power module 70. Since the power module 70 is positioned, the size of the entire apparatus including the case 10 can be reduced. In particular, by adopting the fixing portion 32 in which the positioning rib and the fixing boss are integrated, the clearance between the rib and the boss can be eliminated. Therefore, the positioning of the power module 70 can be performed while reducing the size of the main case 10. It is also possible to reduce the size of the entire apparatus and also reduce the amount of material constituting the main case 10, thereby reducing the weight and cost of the entire apparatus.

  Further, in the power conversion device 1 according to the present embodiment, the fixed portion 32 is at least 2 at a position facing the power module 70 or a diagonal position of the power module 70 so as to sandwich and contact the power module 70. Since it is arranged more than one, the power module 70 can be positioned and fixed while setting the minimum necessary fixing part 32 with a high degree of freedom.

  Moreover, in the power converter device 1 in this embodiment, since the fixing | fixed part 32 is standing from the bottom wall 13 of the case 10 in the aspect connected to the side wall 12 of the case 10, the fixing | fixed part 32 and the case 10 are provided. The support strength and support rigidity of the fixing portion 32 can be increased while eliminating the clearance between the power module 70, the overall size of the apparatus can be reduced, and the power module 70 can be reliably positioned and fixed. it can.

  Moreover, in the power converter 1 in this embodiment, since the fixing | fixed part 32 has a plane part in a part of outer peripheral wall of the fixing | fixed part 32 so that the surface contact with the power module 70, it is a positioning fixing | fixed part. As a result, a large contact area can be secured, and the power module 70 can be firmly fixed.

  Moreover, in the power converter device 1 in this embodiment, since the fixing | fixed part 32 has the taper part 35 made into the inclined surface which retreats as a part above the power module 70 becomes upper, it goes to case 10. When the power module 70 is assembled, the power module 70 can be easily guided into the fixing portion 32, so that the assembly of the power module 70 can be improved.

  Moreover, in the power converter device 1 in this embodiment, since the fixing | fixed part 32 further has the retainer fixing | fixed part 34 which protruded the lower end part of the taper part 35 on the power module 70 side, case 10 When the power module 70 is assembled, the power module 70 can be temporarily fixed to the case 10 before the main fixing by fastening and fixing, and the assembling property of the power module 70 can be further improved.

  In the present invention, the type, shape, arrangement, number, and the like of the members are not limited to the above-described embodiment, and the gist of the invention is appropriately replaced such that the constituent elements are appropriately replaced with those having the same operational effects. Of course, it can be changed as appropriate without departing from the scope.

  As described above, the present invention can provide a power conversion device capable of reducing the size of the entire device including the case while positioning the power module. It is expected to be widely applicable to power conversion devices for vehicles such as hybrid vehicles.

1 ... Power converter 10 ... Lower case (main case)
12 ... Side wall 13 ... Bottom wall 19 ... Opening 20 ... Outer terminal block 28 ... Notch 30 ... Notch 32 ... Fixed boss 33 ... Positioning part 33 '... Positioning part 34 ... Locking part 35 ... Taper part 36 ... collar 38 ... fastening member 40 ... upper case 42 ... side peripheral wall 43 ... upper wall 44 ... notch 46 ... notch 47 ... protruding wall 60 ... heat sink 62 ... main body 64 ... fin 70 ... power module 72 ... module Case 73 ... Color 76 ... Heat spreader 78 ... Signal pin 100 ... Output bus bar

Claims (6)

In a power conversion device comprising: a power module that exhibits a power conversion function for converting power supplied to an electric motor; a case that houses the power module; a heat sink that cools the power module and fixes the case;
The case includes a fixing portion for fixing the case to the heat sink,
The power converter according to claim 1, wherein the fixing portion positions the power module with respect to the case.   The at least two fixing portions are disposed at positions facing each other with the power module sandwiched therebetween or at diagonal positions of the power module so as to sandwich and contact the power module. The power converter according to 1.   The power converter according to claim 1, wherein the fixing unit is erected from a bottom wall of the case in a mode of being connected to a side wall of the case.   4. The power conversion device according to claim 1, wherein the fixing portion has a flat portion at a part of an outer peripheral wall of the fixing portion so as to come into surface contact with the power module.   The power converter according to any one of claims 1 to 4, wherein the fixed portion includes a tapered portion having an inclined surface that retreats as a portion above the power module is upward.   The power converter according to claim 5, wherein the fixing portion further includes a retaining fixing portion in which a lower end portion of the tapered portion protrudes toward the power module.

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