JP2017212401A - Manufacturing method of power converter and cooling structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of power converter capable of improving the cooling efficiency of a heating device, by ensuring adhesion of a heat radiation surface to the case cooling surface of a metal case, and to provide a cooling structure.SOLUTION: A power module 3 and a coolant passage 7 are placed oppositely while sandwiching an inverter case 2. A manufacturing method of an inverter 1A has a passage welding step (Fig. 5), a heating device arrangement step (Fig. 6), and a heating device adhesion fixing step (Fig. 7). The heating device adhesion fixing step (Fig. 7) follows the heating device arrangement step, suppresses convex stress deformation of the inverter case 2 by fastening and fixing force F applied to the outer periphery of the power module 3, and brings the heat radiation surface 3d of the power module 3 into tight contact with the case cooling surface 2d before being fixed to the inverter case 2.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a manufacturing method and a cooling structure of a power conversion device in which a heat generating device and a refrigerant flow channel are arranged to face each other with a metal case interposed therebetween.

  Conventionally, the power module 11 and the cooling water channel 13 are disposed opposite to each other with the opening-attached metal plate 12 interposed therebetween, and the cooling water channel 13 of the electric device includes the case 14 and the metal plate 12 with the opening arranged to close it. Are joined by welding (metal plate joint 19). With this cooling structure, the power module 11 is cooled by cooling water flowing through the cooling water channel 13 (see, for example, Patent Document 1).

JP 2002-314281 A

  However, in the conventional electric device, the metal plate 12 with an opening is installed on the back surface of the case 14, and the metal is melted by heat input along the welded portion of the metal plate 12 with an opening, The weld bead is solidified by cooling the welded portion, and the cooling water channel 13 is formed. Therefore, when the case 14 and the opening-attached metal plate 12 are joined by welding, the case 14 undergoes thermal strain deformation due to warpage in the convex direction. For this reason, if the flat heat dissipation surface of the power module 11 is fixed to the case surface of the case 14 that is deformed by convex distortion, a gap is interposed between the heat dissipation surface and the case surface, thereby reducing the cooling efficiency. There was a problem.

  The present invention has been made paying attention to the above-mentioned problem, and a power conversion device manufacturing method and a cooling structure for improving the cooling efficiency of a heat generating device by ensuring the adhesion of a heat radiating surface to a case cooling surface of a metal case The purpose is to provide.

In order to achieve the above object, in the present invention, a heat generating device and a refrigerant flow path are arranged across a metal case.
The method for manufacturing the power conversion device includes a flow path welding step, a heat generating device arranging step, and a heat generating device contact fixing step.
The heat generating device adhesion fixing process is followed by the heat generating device placement process, and the convex distortion of the metal case is suppressed by the fixing force applied to the outer periphery of the heat generating device, and the heat dissipation surface of the heat generating device is adhered to the case cooling surface and fixed to the metal case. To do.

  As a result, it is possible to provide a method for manufacturing a power conversion device and a cooling structure for the power conversion device that improve the cooling efficiency of the heat generating device by ensuring the adhesion of the heat dissipation surface to the case cooling surface of the metal case.

FIG. 3 is a surface view illustrating a cooling structure of the inverter in the first embodiment. FIG. 3 is a back view showing the cooling structure of the inverter in the first embodiment. FIG. 3 is a cross-sectional view showing a cooling structure of the inverter in the first embodiment. It is sectional drawing which shows the initial state of the manufacturing method of the inverter in Example 1. FIG. FIG. 3 is a cross-sectional view illustrating a flow path welding process of the method for manufacturing an inverter in the first embodiment. It is sectional drawing which shows the heat generating device arrangement | positioning process of the manufacturing method of the inverter in Example 1. FIG. It is sectional drawing which shows the heat generating device contact | adherence fixing process of the manufacturing method of the inverter in Example 1. FIG. It is explanatory drawing which shows the mechanism in which a metal case carries out convex distortion deformation | transformation by the laser welding in the manufacturing method of the inverter in Example 1. FIG. It is sectional drawing which shows the cooling structure of the inverter in Example 2. FIG. It is sectional drawing which shows the cooling structure of the inverter in Example 3. FIG. FIG. 6 is a cross-sectional view showing an inverter cooling structure in Embodiment 4; FIG. 9 is a cross-sectional view illustrating a cooling structure for an inverter according to a fifth embodiment. It is a surface view which shows the cooling structure of the inverter in Example 6. FIG. It is a reverse view which shows the cooling structure of the inverter in Example 6. FIG. FIG. 14 is a cross-sectional view taken along the line GG of FIG. 13 illustrating the cooling structure of the inverter in the sixth embodiment. It is the HH sectional view taken on the line of FIG. 13 which shows the cooling structure of the inverter in Example 6. FIG.

  Hereinafter, the best mode for realizing a method and a cooling structure for a power converter according to the present invention will be described based on Examples 1 to 6 shown in the drawings.

First, the configuration will be described.
The manufacturing method and the cooling structure in the first embodiment are applied to an inverter (an example of a power converter) of a motor generator mounted on a vehicle as a driving source for traveling. The configuration of the first embodiment will be described by dividing it into “inverter cooling structure” and “inverter manufacturing method”.

[Inverter cooling structure]
FIG. 1 shows a front view of the inverter cooling structure in the first embodiment, FIG. 2 shows a rear view, and FIG. 3 shows a cross-sectional view. Hereinafter, based on FIGS. 1-3, the detailed structure of the cooling structure of the inverter in Example 1 is demonstrated.

  As shown in FIGS. 1 to 3, the inverter 1 </ b> A according to the first embodiment includes an inverter case 2 (metal case), a power module 3 (heat generating device), a welded portion 4, a fixed portion 5, and a flow path metal plate. 6 and a refrigerant flow path 7. The inverter 1 </ b> A has a structure in which the power module 3 and the refrigerant flow path 7 are disposed to face each other with the inverter case 2 interposed therebetween, and the power module 3 is cooled by the refrigerant flowing through the refrigerant flow path 7.

  As shown in FIGS. 1 and 3, the inverter case 2 has a power module 3 fixed on the case surface 2 a side and a refrigerant flow path 7 formed on the case back surface 2 b side. The inverter case 2 is formed by press-molding a metal plate, and has a tray shape with a case outer peripheral edge 2c protruding from the power module 3 as shown in FIG. For example, the inverter case 2 is fixed to a case mounting portion protruding from the outer peripheral surface of the motor housing of the motor generator (not shown) by screwing or the like. As a material for the inverter case 2, a metal plate that can be welded such as a cold-rolled steel plate, a stainless steel plate, or an aluminum plate is used.

The power module 3 is one of the heat generating devices, and is configured as an integrated module component having a semiconductor element 3a, an insulating wiring board 3b, a heat spreader 3c (heat radiating member), and an insulating resin 3e.
Here, the “heat generating device” refers to a device that generates heat by transmitting self-heating or heat received from a motor generator or battery (not shown) together with energization.

  When the power module 3 is manufactured, the semiconductor element 3a, the insulating wiring board 3b, and the heat spreader 3c are mounted so as to overlap each other through a joint portion made of a sheet-like solder material or the like. Thereafter, the insulating resin 3e is formed by transfer molding using an epoxy resin or the like. The heat spreader 3c, which is a heat radiating member, is a rectangular plate whose vertical and horizontal dimensions are larger than that of the rectangular parallelepiped insulating resin 3e, and has an outer peripheral portion protruding from the outer periphery of the insulating resin 3e. Of the two plate surfaces of the heat spreader 3c, the opposite surface of the plate surface to which the insulating resin 3e is bonded is the heat radiating surface 3d that contacts the case cooling surface 2d of the inverter case 2. That is, the power module 3 is configured to integrally include a heat spreader 3c having a heat radiating surface 3d that contacts the case cooling surface 2d of the inverter case 2. In addition, as a material of the heat spreader 3c, a highly heat conductive metal material such as an aluminum alloy material is used. Further, as shown in FIG. 1, a high-power PN bus bar 3f and a UVW bus bar 3g are provided so as to protrude from the power module 3.

  The power module 3 is fastened and fixed to the position of the case cooling surface 2 d facing the refrigerant flow path 7 in the case surface 2 a of the inverter case 2. And in the fastening fixation state of the power module 3, as shown in FIG. 3, the heat radiating surface 3d of the heat spreader 3c which contacts the inverter case 2 is brought into close contact with the case cooling surface 2d. Here, the power module 3 is fastened and fixed to the inverter case 2 with the outer peripheral portion of the heat spreader 3 c as a fixing portion 5. The fixing portion 5 includes a fixing screw 5 a and a female screw portion 5 b fixed to the case back surface 2 b of the inverter case 2. And the fixing | fixed part 5 is made into the position of the outer side rather than the welding part 4 across the refrigerant | coolant flow path 7, as shown in FIG.1 and FIG.3.

  The flow path metal plate 6 is configured to have a recessed flow path shape 6a and an outer peripheral flange portion 6b by press-molding a metal plate. As shown in FIG. 3, the recessed flow path shape 6 a forms the coolant flow path 7 in a welded state to the inverter case 2. As shown in FIGS. 1 to 3, the outer peripheral flange portion 6 b is welded to the case back surface 2 b of the inverter case 2 by forming a welded portion 4 (cooled and solidified weld bead) by laser welding or arc welding. Is done. For example, when the welded portion 4 is formed by laser welding, the joining width of the welded portion 4 is about 0.3 mm to 0.7 mm, and it is more preferable to make the joining width uniform about 0.5 mm. The flow path metal plate 6 is formed with a refrigerant input portion 6c into which a refrigerant such as water flows and a refrigerant output portion 6d from which the refrigerant whose temperature has been increased due to heat removal flows out.

[Inverter manufacturing method]
4 shows an initial state of the manufacturing method of the inverter 1A according to the first embodiment, FIG. 5 shows a flow path welding process, FIG. 6 shows a heat generating device placement process, and FIG. 7 shows a heat generating device contact fixing process. Hereinafter, each process which comprises the manufacturing method of the inverter 1A in Example 1 is demonstrated based on FIGS.

  In an initial state before starting the assembly and manufacturing of the inverter 1A, as shown in FIG. 4, as an assembly component, an inverter case 2 (metal case), a power module 3 (heat generating device), a flow path metal plate 6, Prepare. Then, the inverter 1A is manufactured through the flow path welding step (FIG. 5), the heat generating device arrangement step (FIG. 6), and the heat generating device contact fixing step (FIG. 7).

  As shown in FIG. 5, the flow path welding step is performed by laser welding or arc welding of the outer peripheral flange portion 6b (outer peripheral portion) of the flow path metal plate 6 having the recessed flow path shape 6a on the case back surface 2b of the inverter case 2. Weld by, for example. In this welding, by inputting heat along the outline surrounding the recessed flow path shape 6a in the outer peripheral flange portion 6b, the metal of the inverter case 2 and the flow path metal plate 6 is melted to form a weld bead, Thereafter, the weld bead is cooled and solidified. And the inverter case 2 and the flow-path metal plate 6 are integrally weld-joined by the welding part 4 by the solidified weld bead. By this welding joint, the refrigerant flow path 7 through which the refrigerant flows from the refrigerant input portion 6c to the refrigerant output portion 6d is formed by the inverter case 2 and the recessed flow path shape 6a of the flow path metal plate 6.

  As shown in FIG. 6, in the heat generating device arranging step, the power module 3 is arranged at the position of the case cooling surface 2 d facing the refrigerant channel 7 in the case surface 2 a of the inverter case 2 following the channel welding step. To do. At this time, the heat dissipating surface 3d of the heat spreader 3c integrated with the power module 3 has a planar shape, whereas the case cooling surface 2d of the inverter case 2 is convex in a dome shape by heat input and cooling in the flow path welding process. It is distorted.

  As shown in FIG. 7, the heat generating device contact fixing step is followed by the heat generating device arranging step, and the outer peripheral portion of the heat spreader 3 c integrated with the power module 3 is used as the fixing portion 5, and the fixing screw 5 a is used as the female screw portion 5 b. The fastening fixing force F (= fastening torque) is applied by screwing. By this fastening fixing force F, the case cooling surface 2d of the inverter case 2 that is deformed by convex distortion is pressed by the heat radiating surface 3d of the heat spreader 3c, and the convex distortion deformation of the case cooling surface 2d is suppressed. The power module 3 is fixed to the inverter case 2 by raising the fastening fixing force F until the heat radiating surface 3d of the heat spreader 3c comes into close contact with the case cooling surface 2d of the inverter case 2. In this heat generating device contact fixing step, the fixing portion 5 that fixes the power module 3 to the inverter case 2 is positioned outside the welding portion 4 across the refrigerant flow path 7.

Next, the operation will be described.
The operation in the manufacturing method and the cooling structure of the inverter 1A according to the first embodiment is divided into “the generation mechanism of convex distortion deformation by laser welding”, “the cooling efficiency improvement effect of the power module”, and “the heat radiation promotion effect of the power module”. To do.

[Generation mechanism of convex distortion by laser welding]
When the flow path metal plate 6 is joined to the inverter case 2 by laser welding, the inverter case 2 undergoes convex distortion deformation. Hereinafter, based on FIG. 8, the generation mechanism of convex distortion deformation by laser welding will be described.

  Prepare the case and recessed channel shape as described in [I Material] in FIG. 8, and weld the recessed channel shape to the back of the case by laser welding as described in [II Welded Joint] in FIG. Join. After the heat input to the welded part by this welding joint, as described in [III welded part cooling] in FIG. 8, when the heat input welded part is cooled, thermal shrinkage occurs due to solidification of the weld bead. When this heat shrinkage state is observed, the amount of heat shrinkage becomes large because the weld bead width is wide on the concave flow path shape side where the heat input depth is shallow. On the other hand, on the case side where the heat input depth is large, the amount of heat shrinkage is small because the weld bead width is narrow. Thus, since the magnitude of the heat shrinkage varies depending on the difference in the weld bead width, the case surface with a small heat shrinkage warps in the convex direction, and the case deforms in a dome-shaped convex strain.

[Power module cooling efficiency improvement]
As described above, when the flow path metal plate 6 is welded to the inverter case 2, a dome-shaped convex distortion deformation is generated on the inverter case 2 side due to the heat shrinkage strain of the weld bead. On the other hand, in Example 1, it was set as the manufacturing method of inverter 1A which has a flow-path welding process (FIG. 5), a heat generating device arrangement | positioning process (FIG. 6), and a heat generating device contact | adherence fixing process (FIG. 7). Among these, in the heat generating device contact fixing process (FIG. 7), the convex distortion deformation of the inverter case 2 is suppressed by the fastening fixing force F applied to the outer periphery of the power module 3, and the heat radiation surface 3b of the power module 3 is used as the case cooling surface 2d. The inverter case 2 is fixed in close contact.
That is, when the flow path metal plate 6 is welded to the inverter case 2, attention is paid to the fact that the dome-shaped convex strain deformation is generated on the inverter case 2 side due to the heat shrinkage strain of the weld bead, and the dome-shaped convex strain deformation is positively performed. This is used to increase the cooling efficiency of the power module 3.

  For example, when a dome-shaped convex strain deformation occurs on the inverter case side due to the heat shrinkage strain of the weld bead, it is conceivable to form a concave surface that matches the convex strain deformation on the heat dissipation surface of the heat spreader to increase the contact area of the power module. . However, in this case, not only the heat spreading surface of the heat spreader requires a concave surface processing that requires man-hours, but also the contact area cannot be stably expanded, and the surface contactability is not maintained over a long period of time, thereby improving the cooling efficiency. There is a problem that can not be.

  This is because the dome-shaped convex strain deformation due to the heat shrinkage strain of the weld bead varies due to differences in environmental conditions, welding conditions, and the like. For this reason, if the heat dissipation surface of the heat spreader is formed into a concave surface having a certain shape, the contact area varies from product to product. And even if the heat-dissipating surface of the heat spreader and the case cooling surface are in contact, they are only in contact with each other by surface matching. For this reason, for example, when heating / cooling is repeated in a use state, the contacting heat radiating surface and the case cooling surface may be deformed, and the contact area due to surface matching may be reduced compared to the contact area at the time of manufacture.

  On the other hand, in Example 1, it is set as the structure which earns the contact | adherence area of the power module 3 arrange | positioned facing the refrigerant | coolant flow path 7 on both sides of the inverter case 2 by applying the deformation force which suppresses convex distortion deformation. That is, the convex distortion deformation of the inverter case 2 is suppressed by the fastening fixing force F applied to the outer peripheral portion of the power module 3, and the contact area between the heat radiation surface 3b of the heat spreader 3c and the case cooling surface 2d is expanded. For this reason, the cooling effect | action of the power module 3 that the heat which generate | occur | produced in the power module 3 is efficiently extracted by the refrigerant | coolant of the refrigerant flow path 7 through the expanded contact | adherence area is exhibited.

  And the contact | adherence area is expanded in the state which applied fastening fixation force F. FIG. For this reason, the adhesive force which presses against each other continues to act between the heat radiation surface 3b and the case cooling surface 2d. Therefore, for example, even if deformation force acts on the contact surface due to repeated heating / cooling in the usage state, the expanded contact area is stable for a long time as long as the applied deformation force does not exceed the contact force. Maintained.

  Thus, the cooling efficiency of the power module 3 is improved by ensuring the adhesion of the power module 3 to the case cooling surface 2d of the inverter case 2 stably. In addition, the heat dissipating surface 3b of the heat spreader 3c does not particularly require additional surface processing so that the plate surface shape of the material may be maintained. For this reason, the cooling efficiency of the power module 3 can be improved as compared with the comparative example while achieving low man-hours and low costs when compared with the comparative example in which the heat radiating surface is processed to be concave.

In the first embodiment, in the cooling structure of the inverter 1 </ b> A, the power module 3 is fixed to the position of the case cooling surface 2 d facing the refrigerant flow path 7 in the case surface 2 a of the inverter case 2. The heat spreader 3c of the heat spreader 3c that contacts the inverter case 2 is in close contact with the case cooling surface 2d.
Therefore, the cooling efficiency of the power module 3 is improved by ensuring the adhesion of the power module 3 to the case cooling surface 2d of the inverter case 2 in the same manner as the method for manufacturing the inverter 1A.

[Power module heat dissipation acceleration]
In Example 1, in the manufacturing method of the inverter 1A, the heat generating device contact fixing step includes a fixing unit 5 that fixes the power module 3 to the inverter case 2 and a position outside the welding unit 4 across the refrigerant flow path 7. And

  That is, in the thermal strain deformation of the inverter case 2 due to the weld bead, the central portion of the refrigerant flow path 7 surrounded by the welded portion 4 becomes the apex of the convex strain deformation, and the thermal strain deformation remains up to the outer peripheral portion of the welded portion 4. Therefore, in order to suppress the convex distortion deformation of the inverter case 2 by the fastening fixing force F applied to the outer peripheral portion of the power module 3, the position outside the welded portion 4 is set as the fixing portion 5, and the fastening fixing force F is applied to the fixing portion 5. It is effective to secure a close contact area.

  Therefore, the region in which the convex portion deformation of the inverter case 2 is suppressed by the fixing portion 5 is extended to the region outside the welded portion 4 across the refrigerant flow path 7. For this reason, the contact | adherence area (= heat dissipation area) of the heat radiating surface 3b of the heat spreader 3c and the case cooling surface 2d is expanded to the area | region which covers the case cooling surface 2d corresponding to the refrigerant | coolant flow path 7. And the heat radiation from the power module 3 is promoted as much as the contact area increases.

  In the first embodiment, in the cooling structure of the inverter 1 </ b> A, the fixing portion 5 that fixes the power module 3 to the inverter case 2 is positioned outside the welding portion 4 so as to straddle the refrigerant flow path 7.

  Therefore, the area | region which suppresses the convex distortion deformation | transformation of the inverter case 2 is expanded to an outer area | region rather than the welding part 4 similarly to the manufacturing method of inverter 1A. For this reason, the contact | adherence area (= heat dissipation area) of the heat radiating surface 3b of the heat spreader 3c and the case cooling surface 2d is expanded to the area | region which the case cooling surface 2d corresponding to the refrigerant | coolant flow path 7 covers. And the heat radiation from the power module 3 is promoted as much as the contact area increases.

  In the first embodiment, in the method for manufacturing the inverter 1A, the power module 3 integrally includes a heat spreader 3c having a heat radiation surface 3b that contacts the case cooling surface 2d of the inverter case 2. In the heat generating device contact fixing step, the outer peripheral portion of the heat spreader 3 c is fastened and fixed to the inverter case 2.

  That is, by fastening and fixing the outer periphery of the heat spreader 3c to the inverter case 2, the heat radiating surface 3b of the heat spreader 3c and the case cooling surface 2d of the inverter case 2 are tightly fixed. In other words, when the heat radiation surface is formed in the power module 3 except for the heat spreader 3c, the heat radiation area may be narrowed due to the limitation due to the shape of the insulating resin.

  On the other hand, by having the heat spreader 3c as a heat radiating member integrally in the power module 3, the heat radiating area of the heat radiating surface 3b is expanded as compared with the case where there is no heat radiating member. And the heat radiation from the power module 3 is promoted by the amount of the heat radiation area expanded. In addition, in the case of the heat spreader 3c made of a metal material, the heat transferability is improved, and the contact area with the case cooling surface 2d can be further expanded by utilizing the elastic deformation of the heat spreader 3c during fastening and fixing. it can.

In the first embodiment, in the cooling structure of the inverter 1A, the power module 3 has a structure in which a heat spreader 3c having a heat radiating surface 3b in contact with the case cooling surface 2d of the inverter case 2 is integrally formed. The outer peripheral portion of the heat spreader 3 c is fastened and fixed to the inverter case 2.
Therefore, similarly to the method of manufacturing the inverter 1A, the heat spreader 3c as a heat radiating member is integrally provided in the power module 3, so that the heat radiating area of the heat radiating surface 3b can be expanded as compared with the case without the heat radiating member. is there. And the heat radiation from the power module 3 is promoted by the amount of the heat radiation area expanded. In addition, in the case of the heat spreader 3c made of a metal material, the heat transfer performance can be improved, and the contact area with the case cooling surface 2d can be further expanded by utilizing the elastic deformation of the heat spreader 3c during fastening and fixing. be able to.

Next, the effect will be described.
In the manufacturing method and cooling structure of the inverter 1A in the first embodiment, the effects listed below can be obtained.

(1) The heat generating device (power module 3) and the refrigerant flow path 7 are arranged to face each other with the metal case (inverter case 2) interposed therebetween.
The method for manufacturing the power conversion device (inverter 1A) includes a flow path welding step (FIG. 5), a heating device placement step (FIG. 6), and a heating device contact fixing step (FIG. 7).
In the flow path welding step (FIG. 5), the outer periphery (outer peripheral flange portion 6b) of the flow path metal plate 6 having the recessed flow path shape 6a is welded to the case back surface 2b of the metal case (inverter case 2). The coolant channel 7 is formed by the recessed channel shape 6 a of the metal plate 6.
In the heat generating device arrangement step (FIG. 6), following the flow path welding step, the heat generating device (power module) is placed at the position of the case cooling surface 2d facing the refrigerant flow path 7 in the case surface 2a of the metal case (inverter case 2). 3) is arranged.
The heat generating device adhesion fixing process (FIG. 7) suppresses the convex distortion deformation of the metal case (inverter case 2) by the fastening fixing force F applied to the outer peripheral portion of the heat generating device (power module 3) following the heat generating device arrangement process, and generates heat. The heat radiating surface 3d of the device (power module 3) is brought into close contact with the case cooling surface 2d and fixed to the metal case (inverter case 2).
For this reason, manufacture of the power converter device (inverter 1A) which improves the cooling efficiency of the heat generating device (power module 3) by ensuring the adhesion of the heat radiating surface 3d to the case cooling surface 2d of the metal case (inverter case 2). A method can be provided.

(2) In the heat generating device contact fixing step, the fixing portion 5 for fixing the heat generating device (power module 3) to the metal case (inverter case 2) is placed at a position outside the welded portion 4 so as to straddle the refrigerant flow path 7. (FIG. 7).
For this reason, in addition to the effect of (1), the heat radiation from the heat generating device (power module 3) can be promoted by expanding the contact area between the heat radiation surface 3b and the case cooling surface 2d.

(3) The heat generating device (power module 3) integrally includes a heat radiating member (heat spreader 3c) having a heat radiating surface 3b in contact with the case cooling surface 2d of the metal case (inverter case 2).
In the heat generating device contact fixing step, the outer peripheral portion of the heat radiating member (heat spreader 3c) is fixed to the metal case (inverter case 2) (FIG. 7).
For this reason, in addition to the effect of (1) or (2), the heat dissipating area of the heat dissipating surface 3b is expanded by the heat dissipating member (heat spreader 3c), thereby promoting the heat dissipating from the heat generating device (power module 3). Can do.

(4) The heat generating device (power module 3) and the refrigerant flow path 7 are arranged opposite to each other with the metal case (inverter case 2) interposed therebetween.
In the cooling structure of this power converter (inverter 1A), the refrigerant flow path 7 has an outer periphery (outer periphery) of the flow path metal plate 6 formed by a recessed flow path shape 6a welded to the case back surface 2b of the metal case (inverter case 2). It is formed by welding the flange part 6b).
The heat generating device (power module 3) is fixed to the position of the case cooling surface 2d facing the refrigerant flow path 7 in the case surface 2a of the metal case (inverter case 2), and the metal case (inverter case 2) The contacting heat radiating surface 3d is brought into close contact with the case cooling surface 2d (FIG. 3).
For this reason, the cooling of the power converter (inverter 1A) that improves the cooling efficiency of the heat generating device (power module 3) by ensuring the adhesion of the heat radiating surface 3d to the case cooling surface 2d of the metal case (inverter case 2). Structure can be provided.

(5) The fixing portion 5 that fixes the heat generating device (power module 3) to the metal case (inverter case 2) is positioned outside the welded portion 4 so as to straddle the refrigerant flow path 7 (FIG. 3).
For this reason, in addition to the effect of (4), the heat radiation from the heat generating device (power module 3) can be promoted by increasing the contact area between the heat radiation surface 3b and the case cooling surface 2d.

(6) The heat generating device (power module 3) has a structure integrally including a heat radiating member (heat spreader 3c) having a heat radiating surface 3b in contact with the case cooling surface 2d of the metal case (inverter case 2).
The outer peripheral part of the heat radiating member (heat spreader 3c) is fixed to a metal case (inverter case 2) (FIG. 3).
For this reason, in addition to the effect of (4) or (5), the heat dissipating area of the heat dissipating surface 3b is expanded by the heat dissipating member (heat spreader 3c), thereby promoting the heat dissipating from the heat generating device (power module 3). Can do.

  Example 2 is an example in which the heat generating device is a smoothing capacitor, and the smoothing capacitor is fastened and fixed to the inverter case via a bracket member.

First, the configuration will be described.
Similar to the first embodiment, the manufacturing method and the cooling structure in the second embodiment are applied to an inverter (an example of a power converter) of a motor generator mounted on a vehicle as a driving source for traveling. The configuration of the second embodiment will be described by dividing it into “inverter cooling structure” and “inverter manufacturing method”.

[Inverter cooling structure]
FIG. 9 is a cross-sectional view of the inverter cooling structure in the second embodiment. Hereinafter, based on FIG. 9, the detailed structure of the cooling structure of the inverter in Example 2 is demonstrated.

  As shown in FIG. 9, the inverter 1 </ b> B of Example 2 includes an inverter case 2 (metal case), a smoothing capacitor 8 (heating device), a welded portion 4, a fixing portion 5, a flow path metal plate 6, A refrigerant flow path 7 and a bracket member 9 are provided. The inverter 1B has a structure in which the smoothing capacitor 8 and the refrigerant flow path 7 are arranged to face each other with the inverter case 2 interposed therebetween, and the smoothing capacitor 8 is cooled by the refrigerant flowing through the refrigerant flow path 7.

  The smoothing capacitor 8 is one of the heat generating devices, and is an inverter circuit component that stores electricity when the voltage is high and discharges the voltage when the voltage is low to suppress voltage fluctuation. The smoothing capacitor 8 has a rectangular parallelepiped shape, the outer peripheral surface is covered with an insulating film, the front side of the outer peripheral surface is a fixed surface 8a by the bracket member 9, and the back side is the case cooling surface 2d of the inverter case 2. The heat dissipation surface 8b is in contact. That is, unlike the power module 3, the smoothing capacitor 8 has a structure that does not have a heat radiating member having a heat radiating surface 8 b in contact with the case cooling surface 2 d of the inverter case 2 on the back surface side.

  The bracket member 9 fixes the smoothing capacitor 8 to the inverter case 2 while covering the outside of the smoothing capacitor 8. The bracket member 9 includes a heat generating device pressing portion 9a having a shape that covers the outside of the smoothing capacitor 8, and a case fixing portion 9b extending on the outer periphery of the heat generating device pressing portion 9a.

The smoothing capacitor 8 is fastened and fixed via a bracket member 9 to the position of the case cooling surface 2d facing the refrigerant flow path 7 in the case surface 2a of the inverter case 2. In the state where the smoothing capacitor 8 is fastened and fixed by the bracket member 9, as shown in FIG. 9, the heat dissipation surface 8b of the smoothing capacitor 8 that contacts the inverter case 2 is brought into close contact with the case cooling surface 2d. . Here, the smoothing capacitor 8 fixed via the bracket member 9 is fastened and fixed to the inverter case 2 with the case fixing portion 9b of the bracket member 9 as the fixing portion 5. The fixing portion 5 includes a fixing screw 5 a and a female screw portion 5 b fixed to the case back surface 2 b of the inverter case 2. And the fixing | fixed part 5 is made into the position of the outer side rather than the welding part 4 across the refrigerant | coolant flow path 7, as shown in FIG.
Since other configurations are the same as those of the first embodiment, the corresponding components are denoted by the same reference numerals and description thereof is omitted.

[Inverter manufacturing method]
In an initial state before the assembly manufacturing of the inverter 1B of the second embodiment is started, as an assembly component, an inverter case 2 (metal case), a smoothing capacitor 8 (heat generating device), a flow path metal plate 6, and a bracket member 9 are used. And prepare. Then, the inverter 1B is manufactured through the flow path welding step, the heat generating device arranging step, and the heat generating device contact fixing step.

  The flow path welding step is the same as in FIG. 5 of the first embodiment, and the outer peripheral flange portion 6b (outer peripheral portion) of the flow path metal plate 6 having the recessed flow path shape 6a is laser-formed on the case back surface 2b of the inverter case 2. Weld and join by welding or arc welding. By this welding joint, the refrigerant flow path 7 is formed by the recessed flow path shape 6 a of the inverter case 2 and the flow path metal plate 6.

  The heating device arrangement step is the same as that in FIG. 6 of the first embodiment, and is smoothed at the position of the case cooling surface 2d facing the refrigerant flow path 7 in the case surface 2a of the inverter case 2 following the flow path welding process. A capacitor 8 is disposed. At this time, the heat radiating surface 8b of the smoothing capacitor 8 has a planar shape, whereas the case cooling surface 2d of the inverter case 2 is convexly deformed into a dome shape by heat input and cooling in the flow path welding process.

  In the heat generating device contact fixing step, following the heat generating device arranging step, the outer periphery of the smoothing capacitor 8 is covered with the bracket member 9, the case fixing portion 9b (outer peripheral portion) of the bracket member 9 is used as the fixing portion 5, and the fixing screw 5a is the female. A fastening fixing force F (= fastening torque) is applied by screwing into the screw portion 5b. By this fastening fixing force F, the case cooling surface 2d of the inverter case 2 that is deformed in convex distortion is pressed by the heat radiating surface 8b of the smoothing capacitor 8, and the convex distortion deformation of the case cooling surface 2d is suppressed. Then, the smoothing capacitor 8 is fixed to the inverter case 2 by raising the fastening fixing force F until the heat radiating surface 8b of the smoothing capacitor 8 is in close contact with the case cooling surface 2d of the inverter case 2. In this heat generating device contact fixing process, the fixing part 5 that fixes the smoothing capacitor 8 to the inverter case 2 is positioned outside the welding part 4 in the flow path welding process.

Next, the operation will be described.
In the second embodiment, in the method for manufacturing the inverter 1B, a bracket member 9 is prepared for fixing the smoothing capacitor 8 to the inverter case 2 in a state where the outside of the smoothing capacitor 8 is covered. In the heat generating device contact fixing step, the smoothing capacitor 8 is fastened and fixed to the inverter case 2 via the bracket member 9.

  That is, the bracket member 9 that covers the outer periphery of the smoothing capacitor 8 is fastened and fixed to the inverter case 2, whereby the heat radiation surface 8 b of the smoothing capacitor 8 and the case cooling surface 2 d of the inverter case 2 are tightly fixed. That is, the fastening fixing force F applied to the fixing portion 5 acts in a distributed manner on the case fixing surface 8 a of the smoothing capacitor 8 via the bracket member 9. The dispersed force acting on the case fixing surface 8a acts on the case cooling surface 2d from the heat radiation surface 8b of the smoothing capacitor 8 to suppress the convex distortion deformation of the case cooling surface 2d.

  Therefore, when the heat generating device is the smoothing capacitor 8 thinly covered with an insulating film or the like, the contact area between the heat radiation surface 8b of the smoothing capacitor 8 and the case cooling surface 2d is ensured while ensuring the insulating property of the smoothing capacitor 8. be able to.

  In Example 2, the cooling structure of the inverter 1B includes a bracket member 9 that fixes the smoothing capacitor 8 to the inverter case 2 in a state where the outside of the smoothing capacitor 8 is covered. The smoothing capacitor 8 is fixed to the inverter case 2 via the bracket member 9.

Therefore, similarly to the manufacturing method of the inverter 1B, when the heat generating device is the smoothing capacitor 8 thinly covered with an insulating film or the like, the heat dissipation surface 8b of the smoothing capacitor 8 and the case cooling are ensured while ensuring the insulating property of the smoothing capacitor 8. A close contact area with the surface 2d can be secured.
Since other operations are the same as those of the first embodiment, description thereof is omitted.

Next, the effect will be described.
In the manufacturing method and cooling structure of the inverter 1B in the second embodiment, the effects listed below can be obtained.

(7) A bracket member 9 is prepared for fixing the heat generating device (smoothing capacitor 8) to the metal case (inverter case 2) while covering the outside of the heat generating device (smoothing capacitor 8).
In the heat generating device contact fixing step, the heat generating device (smoothing capacitor 8) is fixed to the metal case (inverter case 2) through the bracket member 9 (FIG. 9).
For this reason, in addition to the effects (1) and (2) above, when the heat generating device is thinly covered with an insulating film or the like, the heat generating device (smoothing capacitor 8) is secured while ensuring the insulating property of the heat generating device. A close contact area between the heat radiation surface 8b and the case cooling surface 2d can be ensured.

(8) A bracket member 9 is provided for fixing the heat generating device (smoothing capacitor 8) to the metal case (inverter case 2) in a state of covering the outside of the heat generating device (smoothing capacitor 8).
The heat generating device (smoothing capacitor 8) is fixed to the metal case (inverter case 2) via the bracket member 9 (FIG. 9).
For this reason, in addition to the effects (4) and (5) above, when the heat generating device is thinly covered with an insulating film or the like, the insulating property of the heat generating device (smoothing capacitor 8) is ensured while the heat generating device is A close contact area between the heat radiation surface 8b and the case cooling surface 2d can be ensured.

  Example 3 is an example in which the heat generating device is a first high-power busbar module, and an insulating resin and a fixing resin that cover the high-power busbar are fastened and fixed to the inverter case.

First, the configuration will be described.
Similar to the first embodiment, the manufacturing method and the cooling structure in the third embodiment are applied to an inverter (an example of a power converter) of a motor generator mounted on a vehicle as a driving source for traveling. The configuration of the third embodiment will be described separately for “inverter cooling structure” and “inverter manufacturing method”.

[Inverter cooling structure]
FIG. 10 is a cross-sectional view of the inverter cooling structure according to the third embodiment. Hereinafter, based on FIG. 10, the detailed structure of the cooling structure of the inverter in Example 3 is demonstrated.

  As shown in FIG. 10, the inverter 1 </ b> C of Example 3 includes an inverter case 2 (metal case), a first high-voltage bus bar module 10 (heat generating device), a welded portion 4, a fixed portion 5, and a flow path metal plate. 6 and a refrigerant flow path 7. The inverter 1C has a structure in which the first high-power busbar module 10 and the refrigerant flow path 7 are arranged to face each other with the inverter case 2 interposed therebetween, and the first high-power busbar module 10 is cooled by the refrigerant flowing through the refrigerant flow path 7.

  The first high-power busbar module 10 is one of the heat generating devices, and includes a high-power busbar 10a, an insulating resin 10b, and a fixed resin 10c. The high-power bus bar 10a includes a U-phase bus bar, a V-phase bus bar, a W-phase bus bar, and the like that connect the power module and the motor generator. The insulating resin 10b is formed by resin molding so as to cover the outer periphery of the high voltage bus bar 10a. The fixing resin 10c is obtained by integrally extending the insulating resin 10b to the outside of the high-voltage bus bar 10a as a fixing resin portion to be fixed to the inverter case 2. Then, the resin back surfaces of the insulating resin 10b and the fixed resin 10c serve as the heat radiating surface 10d that contacts the case cooling surface 2d of the inverter case 2. That is, the first high-power busbar module 10 has a structure in which an insulating resin 10b and a fixed resin 10c having a heat radiating surface 10d in contact with the case cooling surface 2d of the inverter case 2 are integrally provided as heat radiating members.

The first high-power busbar module 10 is fastened and fixed at the position of the case cooling surface 2 d facing the refrigerant flow path 7 in the case surface 2 a of the inverter case 2. And in the fastening fixation state of the 1st high-power busbar module 10, as shown in FIG. 10, the heat radiating surface 10d which contacts the inverter case 2 is brought into close contact with the case cooling surface 2d. Here, the first high-power busbar module 10 is fastened and fixed to the inverter case 2 with the fixing resin 10c formed on the outer periphery of the insulating resin 10b as the fixing portion 5. The fixing portion 5 includes a fixing screw 5 a and a female screw portion 5 b fixed to the case back surface 2 b of the inverter case 2. And the fixing | fixed part 5 is made into the position outside the welding part 4 so that the refrigerant | coolant flow path 7 may be straddled, as shown in FIG.
Since other configurations are the same as those of the first embodiment, the corresponding components are denoted by the same reference numerals and description thereof is omitted.

[Inverter manufacturing method]
In an initial state before the assembly and manufacturing of the inverter 1C of Example 3 is started, as an assembly part, an inverter case 2 (metal case), a first high-voltage bus bar module 10 (heat generating device), a flow path metal plate 6, Prepare. Then, the inverter 1C is manufactured through the flow path welding step, the heat generating device arranging step, and the heat generating device contact fixing step.

  The flow path welding step is the same as in FIG. 5 of the first embodiment, and the outer peripheral flange portion 6b (outer peripheral portion) of the flow path metal plate 6 having the recessed flow path shape 6a is laser-formed on the case back surface 2b of the inverter case 2. Weld and join by welding or arc welding. By this welding joint, the refrigerant flow path 7 is formed by the recessed flow path shape 6 a of the inverter case 2 and the flow path metal plate 6.

  The heat generating device arranging step is the same as that in FIG. 6 of the first embodiment, and following the flow path welding step, the case surface 2a of the inverter case 2 is positioned at the position of the case cooling surface 2d facing the refrigerant flow path 7. One high power bus bar module 10 is arranged. At this time, the heat radiating surface 10d by the back surfaces of the insulating resin 10b and the fixing resin 10c has a planar shape, whereas the case cooling surface 2d of the inverter case 2 is convexly distorted into a dome shape by heat input and cooling in the flow path welding process. It is deformed.

  The heat generating device contact fixing step is fixed by fastening the fixing resin 10c (outer peripheral portion) of the first high voltage bus bar module 10 as the fixing portion 5 and screwing the fixing screw 5a into the female screw portion 5b, following the heat generating device arrangement step. Apply force F (= fastening torque). By this fastening fixing force F, the case cooling surface 2d of the inverter case 2 that is deformed in convex distortion is pressed by the heat radiation surface 10d of the first high-voltage bus bar module 10, and the convex distortion deformation of the case cooling surface 2d is suppressed. Then, the first high-power busbar module 10 is fixed to the inverter case 2 by raising the fastening fixing force F until the heat radiation surface 10d of the first high-power busbar module 10 comes into close contact with the case cooling surface 2d of the inverter case 2. . In this heat generating device contact fixing step, the fixing portion 5 that fixes the first high-voltage bus bar module 10 to the inverter case 2 is positioned outside the welded portion 4 so as to straddle the refrigerant flow path 7.

  As for the operation of the third embodiment, when the power module 3 of the first embodiment is replaced with the first high-power busbar module 10, as in the first embodiment, “the cooling efficiency improvement effect of the first high-power busbar module”, “first high-power busbar module” "Heat radiation promotion effect of bus bar module".

  Therefore, in the method for manufacturing the inverter 1C and the cooling structure in the third embodiment, the effects described in (1) to (6) of the first embodiment can be obtained as in the first embodiment.

  Example 4 is an example in which the heat generating device is a second high-power busbar module, and an insulating resin covering the high-power busbar is welded and fixed to the inverter case via a bracket member.

First, the configuration will be described.
Similar to the first embodiment, the manufacturing method and the cooling structure in the fourth embodiment are applied to an inverter (an example of a power converter) of a motor generator mounted on a vehicle as a driving source for traveling. The configuration of the fourth embodiment will be described separately for “inverter cooling structure” and “inverter manufacturing method”.

[Inverter cooling structure]
FIG. 11 is a cross-sectional view of the inverter cooling structure in the fourth embodiment. Hereinafter, based on FIG. 11, the detailed structure of the cooling structure of the inverter in Example 4 is demonstrated.

  As shown in FIG. 11, the inverter 1D of the fourth embodiment includes an inverter case 2 (metal case), a second high-voltage bus bar module 11 (heat generating device), a welded portion 4, a fixed portion 5, and a flow path metal plate. 6, a refrigerant flow path 7, and a bracket member 9. The inverter 1D has a structure in which the second high-power busbar module 11 and the refrigerant flow path 7 are arranged to face each other with the inverter case 2 interposed therebetween, and the second high-power busbar module 11 is cooled by the refrigerant flowing through the refrigerant flow path 7.

  The second high-power bus bar module 11 is one of the heat generating devices, and includes a high-power bus bar 11a and an insulating resin 11b. The high-power bus bar 11a includes a U-phase bus bar, a V-phase bus bar, a W-phase bus bar, and the like that connect the power module and the motor generator. The insulating resin 11b is formed by resin molding so as to cover the outer periphery of the high voltage bus bar 11a. That is, the second high-voltage bus bar module 11 has a structure integrally including an insulating resin 11b having a heat radiation surface 11d that contacts the case cooling surface 2d of the inverter case 2.

  The bracket member 9 welds and fixes the second high-voltage bus bar module 11 to the inverter case 2 while covering the outside of the insulating resin 11b. The bracket member 9 includes a heat generating device pressing portion 9a having a shape covering the outside of the insulating resin 11b, and a case fixing portion 9b extending on the outer periphery of the heat generating device pressing portion 9a.

The second high-voltage bus bar module 11 is welded and fixed to the position of the case cooling surface 2 d facing the refrigerant flow path 7 on the case surface 2 a of the inverter case 2 via the bracket member 9. Then, the insulating resin 11b containing the high-voltage bus bar 11a has a heat radiating surface 11d of the insulating resin 11b in contact with the inverter case 2 with respect to the case cooling surface 2d as shown in FIG. In close contact. Here, the insulating resin 11b fixed via the bracket member 9 is fixed to the inverter case 2 by welding using the case fixing portion 9b of the bracket member 9 as the fixing portion 5. The fixed part 5 is constituted by a welded part 5c by laser welding or the like. And the fixing | fixed part 5 is made into the position outside the welding part 4 so that the refrigerant | coolant flow path 7 may be straddled, as shown in FIG.
Since other configurations are the same as those of the first embodiment, the corresponding components are denoted by the same reference numerals and description thereof is omitted.

[Inverter manufacturing method]
In an initial state before starting the assembly and manufacturing of the inverter 1D of the fourth embodiment, as assembly parts, an inverter case 2 (metal case), a second high-voltage bus bar module 11 (heat generating device), a flow path metal plate 6, A bracket member 9 is prepared. Then, the inverter 1D is manufactured through the flow path welding process, the heat generating device arrangement process, and the heat generating device contact fixing process.

  The flow path welding step is the same as in FIG. 5 of the first embodiment, and the outer peripheral flange portion 6b (outer peripheral portion) of the flow path metal plate 6 having the recessed flow path shape 6a is laser-formed on the case back surface 2b of the inverter case 2. Weld and join by welding or arc welding. By this welding joint, the refrigerant flow path 7 is formed by the recessed flow path shape 6 a of the inverter case 2 and the flow path metal plate 6.

  The heating device arrangement step is the same as that in FIG. 6 of the first embodiment. Following the flow path welding step, the case cooling surface 2d of the case surface 2a of the inverter case 2 facing the refrigerant flow path 7 is positioned at the position of the case cooling surface 2d. The second high power bus bar module 11 is arranged. At this time, the heat radiating surface 11d of the second high voltage bus bar module 11 has a flat shape, whereas the case cooling surface 2d of the inverter case 2 is convexly deformed into a dome shape by heat input and cooling in the flow path welding process. Yes.

  In the heat generating device contact fixing step, following the heat generating device arranging step, the outer periphery of the second high-voltage bus bar module 11 is covered with the bracket member 9, and the case fixing portion 9 b (outer peripheral portion) of the bracket member 9 is used as the fixing portion 5. Etc. to apply welding fixing force F ′ (= welding torque). By this welding fixing force F ', the case cooling surface 2d of the inverter case 2 that is deformed by convex distortion is pressed by the heat radiating surface 11d of the insulating resin 11b, and the convex distortion deformation of the case cooling surface 2d is suppressed. Then, as the welding fixing force F ′, the heat radiation surface 11 d of the insulating resin 11 b gives a force of a magnitude that comes into close contact with the case cooling surface 2 d of the inverter case 2, thereby fixing the second high-voltage bus bar module 11 to the inverter case 2. To do. In this heat generating device tightly fixing step, the fixing portion 5 that fixes the second high-voltage bus bar module 11 to the inverter case 2 is positioned outside the welding portion 4 so as to straddle the refrigerant flow path 7.

  About the effect | action of Example 4, if the smoothing capacitor 8 of Example 2 is substituted to the 2nd high-power busbar module 11, the effect | action similar to Example 2 will be shown.

  Therefore, in the manufacturing method and the cooling structure of the inverter 1D in the fourth embodiment, as in the second embodiment, the effects described in the first embodiment (1), (2), (4), (5), In addition, the effects described in (7) and (8) of Example 2 can be obtained.

  The fifth embodiment is an example in which the heat generating device is the third high-power busbar module, and the heat spreader included in the third high-power busbar module is fastened and fixed to the inverter case.

First, the configuration will be described.
Similar to the first embodiment, the manufacturing method and the cooling structure in the fifth embodiment are applied to an inverter (an example of a power converter) of a motor generator mounted on a vehicle as a driving source for traveling. The configuration of the fifth embodiment will be described separately for “inverter cooling structure” and “inverter manufacturing method”.

[Inverter cooling structure]
FIG. 12 is a cross-sectional view of the inverter cooling structure in the fifth embodiment. Hereinafter, based on FIG. 12, the detailed structure of the cooling structure of the inverter in Example 5 is demonstrated.

  As shown in FIG. 12, the inverter 1E of Example 5 includes an inverter case 2 (metal case), a third high-voltage bus bar module 12 (heat generating device), a welded portion 4, a fixed portion 5, and a flow path metal plate. 6 and a refrigerant flow path 7. The inverter 1E has a structure in which the third high-power busbar module 12 and the refrigerant flow path 7 are arranged to face each other with the inverter case 2 interposed therebetween, and the third high-power busbar module 12 is cooled by the refrigerant flowing through the refrigerant flow path 7.

  The third high-power busbar module 12 is one of heat generating devices, and is configured as an integrated module component having a high-power busbar 12a, an insulating resin 12b, a heat spreader 12c (heat dissipating member), and fins 12e.

  In manufacturing the third high-power bus bar module 12, the high-power bus bar 12a is disposed between the fins 12e provided integrally with the heat spreader 12c. Then, the insulating resin 12b is formed by using the fin 3e as a mold and performing transfer molding using an epoxy resin or the like. The heat spreader 12c, which is a heat radiating member, is a rectangular plate whose vertical and horizontal dimensions are larger than that of a rectangular parallelepiped mold resin portion (high-power bus bar 12a, insulating resin 12b, fin 12e), and an outer periphery protruding from the outer periphery of the mold resin portion. Part. The back surface of the heat spreader 12 c is a heat radiating surface 12 d that contacts the case cooling surface 2 d of the inverter case 2. That is, the third high-power busbar module 12 has a structure integrally including a heat spreader 12c (heat radiating member) having a heat radiating surface 12d that contacts the case cooling surface 2d of the inverter case 2.

The third high-power busbar module 12 is fastened and fixed to the position of the case cooling surface 2d facing the refrigerant flow path 7 in the case surface 2a of the inverter case 2. Then, in the fastened and fixed state of the third high-voltage bus bar module 12, as shown in FIG. 12, the heat dissipating surface 12d of the heat spreader 12c that contacts the inverter case 2 is brought into close contact with the case cooling surface 2d. Here, the third high-voltage bus bar module 12 is fastened and fixed to the inverter case 2 with the outer peripheral portion of the heat spreader 12c as the fixing portion 5. The fixing portion 5 includes a stud bolt 5d fixed to the inverter case 2 and a nut 5e that is screwed into the stud bolt 5d. And the fixing | fixed part 5 is made into the position of the outer side rather than the welding part 4 so that the refrigerant | coolant flow path 7 may be straddled, as shown in FIG.
Since other configurations are the same as those of the first embodiment, the corresponding components are denoted by the same reference numerals and description thereof is omitted.

[Inverter manufacturing method]
In the initial state before the start of assembly manufacturing of the inverter 1E of the fifth embodiment, as an assembly component, an inverter case 2 (metal case), a third high-voltage bus bar module 12 (heat generating device), a flow path metal plate 6, Prepare. Then, the inverter 1C is manufactured through the flow path welding step, the heat generating device arranging step, and the heat generating device contact fixing step.

  The flow path welding step is the same as in FIG. 5 of the first embodiment, and the outer peripheral flange portion 6b (outer peripheral portion) of the flow path metal plate 6 having the recessed flow path shape 6a is laser-formed on the case back surface 2b of the inverter case 2. Weld and join by welding or arc welding. By this welding joint, the refrigerant flow path 7 is formed by the recessed flow path shape 6 a of the inverter case 2 and the flow path metal plate 6.

  The heat generating device arranging step is the same as that in FIG. 6 of the first embodiment, and following the flow path welding step, the case surface 2a of the inverter case 2 is positioned at the position of the case cooling surface 2d facing the refrigerant flow path 7. Three high-power busbar modules 12 are arranged. At this time, the heat radiating surface 12d of the third high voltage bus bar module 12 has a planar shape, whereas the case cooling surface 2d of the inverter case 2 is convexly deformed into a dome shape by heat input and cooling in the flow path welding process. Yes.

  In the heat generating device tightly fixing step, following the heat generating device arranging step, the outer peripheral portion of the heat spreader 12c is used as the fixing portion 5, and a fastening fixing force F (= fastening torque) is applied by screwing the stud bolt 5d into the nut 5e. By this fastening fixing force F, the case cooling surface 2d of the inverter case 2 that is deformed by convex distortion is pressed by the heat radiation surface 12d of the third high-voltage bus bar module 12, and the convex distortion deformation of the case cooling surface 2d is suppressed. Then, the third high-power bus bar module 12 is fixed to the inverter case 2 by raising the fastening fixing force F until the heat radiation surface 12d of the third high-power bus bar module 12 comes into close contact with the case cooling surface 2d of the inverter case 2. . In this heat generating device contact fixing step, the fixing portion 5 that fixes the third high-voltage bus bar module 12 to the inverter case 2 is positioned outside the welding portion 4 so as to straddle the refrigerant flow path 7.

  When the power module 3 of the first embodiment is replaced with the third high-power busbar module 12, the operation of the fifth embodiment is the same as in the first embodiment, “the effect of improving the cooling efficiency of the third high-power busbar module”, “third high-power busbar module”. "Heat radiation promotion effect of bus bar module".

  Therefore, in the method for manufacturing the inverter 1E and the cooling structure in the fifth embodiment, the effects described in (1) to (6) of the first embodiment can be obtained as in the first embodiment.

  The sixth embodiment is an example in which the heat generating device is an inverter module, and the inverter module is fastened and fixed to the inverter case.

First, the configuration will be described.
Similar to the first embodiment, the manufacturing method and the cooling structure in the sixth embodiment are applied to an inverter (an example of a power converter) of a motor generator mounted on a vehicle as a driving source for traveling. The configuration of the sixth embodiment will be described by dividing it into “inverter cooling structure” and “inverter manufacturing method”.

[Inverter cooling structure]
13 is a front view of the inverter cooling structure in the sixth embodiment, FIG. 14 is a rear view, FIG. 15 is a sectional view taken along line GG in FIG. 13, and FIG. 16 is a line HH in FIG. A cross-sectional view is shown. The detailed configuration of the inverter cooling structure according to the sixth embodiment will be described below with reference to FIGS.

  As shown in FIGS. 13 to 16, the inverter 1 </ b> F of Example 6 includes an inverter case 2 (metal case), an inverter module IM (heat generating device), a welded portion 4, a fixed portion 5, and a flow path metal plate. 6 and a refrigerant flow path 7. The inverter 1F has a structure in which the inverter module IM and the refrigerant flow path 7 are opposed to each other with the inverter case 2 interposed therebetween, and the inverter module IM is cooled by the refrigerant flowing through the refrigerant flow path 7.

  As shown in FIG. 13, the inverter module IM includes a power module 13, a smoothing capacitor 14, a discharge resistor 15, a driver board 16, a PN bus bar 17, a UVW bus bar 18, a current sensor 19, and an insulating resin. 20.

Each component constituting the inverter module IM is fastened and fixed to a position of the case cooling surface 2d facing the refrigerant flow path 7 in the case surface 2a of the inverter case 2. In the fastening and fixing state of the inverter module IM, as shown in FIG. 15, the heat radiation surfaces of the power module 13, the smoothing capacitor 14, the discharge resistor 15, the current sensor 19, and the insulating resin 20 are in contact with the case cooling surface 2d. It is in close contact. Here, as shown in FIG. 13, the inverter module IM is fastened and fixed to the inverter case 2 with the outer peripheral portion of the power module 13, the smoothing capacitor 14, the current sensor 19, and the insulating resin 20 as the fixing portion 5. As is clear from the comparison between FIG. 13 and FIG. 14, the fixed portion 5 is positioned outside the welded portion 4 so as to straddle the refrigerant flow path 7.
Since other configurations are the same as those of the first embodiment, the corresponding components are denoted by the same reference numerals and description thereof is omitted.

[Inverter manufacturing method]
In an initial state before starting the assembly and manufacturing of the inverter 1F of the sixth embodiment, an inverter case 2 (metal case), an inverter module IM (heat generating device), and a flow path metal plate 6 are prepared as assembly parts. . Then, the inverter 1C is manufactured through the flow path welding step, the heat generating device arranging step, and the heat generating device contact fixing step.

  The flow path welding step is the same as in FIG. 5 of the first embodiment, and the outer peripheral flange portion 6b (outer peripheral portion) of the flow path metal plate 6 having the recessed flow path shape 6a is laser-formed on the case back surface 2b of the inverter case 2. Weld and join by welding or arc welding. By this welding joint, the refrigerant flow path 7 is formed by the recessed flow path shape 6 a of the inverter case 2 and the flow path metal plate 6.

  The heat generating device arrangement step is the same as that in FIG. 6 of the first embodiment. Following the flow path welding step, the case heating surface 2d of the inverter case 2 is previously placed at the position of the case cooling surface 2d facing the refrigerant flow path 7. An inverter module IM assembled in an integral structure is arranged. At this time, the heat radiating surface of the inverter module IM has a planar shape, whereas the case cooling surface 2d of the inverter case 2 is convexly deformed into a dome shape by heat input and cooling in the flow path welding process.

  In the heat generating device contact fixing step, following the heat generating device arranging step, the outer peripheral portion of the inverter module IM is set as the fixing portion 5, and the fixing screw 5a is screwed into the female screw portion 5b, whereby the fastening fixing force F (= fastening torque) is obtained. Add. By this fastening fixing force F, the case cooling surface 2d of the inverter case 2 that is deformed by convex distortion is pressed by the heat dissipation surface of the inverter module IM, and the convex distortion deformation of the case cooling surface 2d is suppressed. Then, the inverter module IM is fixed to the inverter case 2 by raising the fastening fixing force F until the heat radiation surface of the inverter module IM comes into close contact with the case cooling surface 2d of the inverter case 2. In this heat generating device tightly fixing step, the fixing portion 5 that fixes the inverter module IM to the inverter case 2 is positioned outside the welding portion 4 so as to straddle the refrigerant flow path 7.

  When the power module 3 of the first embodiment is replaced with the inverter module IM, the operation of the sixth embodiment exhibits the “inverter module cooling efficiency improving operation” and the “inverter module heat dissipation promoting operation” as in the first embodiment.

  Therefore, in the method for manufacturing the inverter 1F and the cooling structure in the sixth embodiment, the effects described in (1) to (6) of the first embodiment can be obtained as in the first embodiment.

  As mentioned above, although the manufacturing method and cooling structure of the power converter device of this invention were demonstrated based on Examples 1-6, about a concrete structure, it is not restricted to these Examples, Design changes and additions are allowed without departing from the spirit of the invention according to each claim.

  In the first embodiment, the heat generating device is the power module 3, and in the second embodiment, the heat generating device is the smoothing capacitor 8. In the third to fifth embodiments, an example in which the heat generating devices are the first high-power busbar module 10, the second high-power busbar module 11, and the third high-power busbar module 12 is shown. Furthermore, in the sixth embodiment, an example in which the heat generating device is the inverter module IM is shown. However, as the heat generating device, in addition to the first to sixth embodiments, for example, one or two or more combination parts of a power module, a smoothing capacitor, a discharge resistor, a high voltage bus bar, and the like may be used. .

  Examples 1, 2, 3, 5, and 6 show examples in which the fixing of the heat generating device and the metal case is fastened and fixed by bolts and nuts, and Example 4 shows an example of fixing the heat generating device and the metal case by welding. Indicated. However, the fixing method of the heat generating device and the metal case may be an example in which fastening and welding are used in combination.

  In the first to sixth embodiments, the example in which the method for manufacturing the power converter and the cooling structure of the present invention are applied to an inverter used as an AC / DC converter of a motor generator has been shown. However, the manufacturing method and cooling structure of the present invention uses a heat generating device, and converts one or more of electrical characteristics such as voltage, current, frequency, phase, number of phases, and waveforms while suppressing substantial power loss. It is applicable also to various power converters other than an inverter.

1A, 1B, 1C, 1D, 1E, 1F Inverter (power converter)
2 Inverter case (metal case)
2a Case surface 2b Case back surface 2c Case outer peripheral edge 2d Case cooling surface 3 Power module (heating device)
3d Heat dissipation surface 4 Welded portion 5 Fixed portion 6 Channel metal plate 6a Recessed channel shape 6b Outer peripheral flange (outer peripheral portion)
7 Refrigerant flow path 8 Smoothing capacitor (heat generating device)
8b Heat radiation surface 9 Bracket member 10 First high voltage bus bar module (heat generating device)
10d Heat dissipation surface 11 Second high voltage bus bar module (heat generating device)
11d Heat dissipation surface 12 Third high voltage bus bar module (heat generating device)
12d Heat dissipation surface IM Inverter module (heat generating device)

Claims (8)

In the method for manufacturing the power conversion device in which the heat generating device and the refrigerant flow path are arranged to face each other with the metal case interposed therebetween,
A flow path welding step of welding the outer periphery of a flow path metal plate having a recessed flow path shape to the case back surface of the metal case, and forming the refrigerant flow path by the recessed flow path shape of the flow path metal plate;
Following the flow path welding step, among the case surface of the metal case, a heat generating device disposing step of disposing the heat generating device at a position of a case cooling surface facing the refrigerant flow path,
Following the heat generating device placement step, the convex deformation of the metal case is suppressed by a fixing force applied to the outer peripheral portion of the heat generating device, and the heat radiating surface of the heat generating device is brought into close contact with the case cooling surface and fixed to the metal case. A heat generating device adhesion fixing process;
The manufacturing method of the power converter device characterized by having. In the manufacturing method of the power converter device described in Claim 1,
In the heat generating device contact fixing step, the fixing portion that fixes the heat generating device to the metal case is positioned outside the welded portion so as to straddle the refrigerant flow path. . In the manufacturing method of the power converter device described in Claim 1 or 2,
The heat generating device integrally includes a heat dissipating member having a heat dissipating surface in contact with the case cooling surface of the metal case,
In the heat generating device contact fixing step, the outer peripheral portion of the heat radiating member is fixed to the metal case. In the manufacturing method of the power converter device described in Claim 1 or 2,
Preparing a bracket member for fixing the heat generating device to the metal case in a state of covering the outside of the heat generating device,
In the heat generating device contact fixing step, the heat generating device is fixed to the metal case via the bracket member. In the cooling structure of the power conversion device in which the heat generating device and the refrigerant flow path are opposed to each other with the metal case interposed therebetween,
The refrigerant flow path is formed by welding the outer periphery of the flow path metal plate with a recessed flow path shape welded to the case back surface of the metal case,
The heat generating device is fixed to a position of a case cooling surface facing the refrigerant flow path in a case surface of the metal case, and a heat radiating surface in contact with the metal case is in close contact with the case cooling surface. A cooling structure for a power conversion device, characterized by being in a state. In the cooling structure of the power conversion device according to claim 5,
The fixing part for fixing the heat generating device to the metal case is positioned outside the welded part so as to straddle the refrigerant flow path. A method for manufacturing a power conversion device and a cooling structure. In the cooling structure of the power converter according to claim 5 or 6,
The heat generating device has a structure integrally including a heat radiating member having a heat radiating surface in contact with the case cooling surface of the metal case,
A cooling structure for a power converter, wherein an outer peripheral portion of the heat radiating member is fixed to the metal case. In the cooling structure of the power converter according to claim 5 or 6,
A bracket member for fixing the heat generating device to the metal case in a state of covering the outside of the heat generating device;
The heat generating device is fixed to the metal case via the bracket member. A cooling structure for a power converter.