JP2018074010A - Power conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize simplification weight saving of a configuration of a power conversion device and reduction in production cost of the power conversion device.SOLUTION: A casing 16 that supports a heat sink 14 that cools a circuit board 12 includes a first support member 30a, a second support member 30b, and a casing main body 32. On the first support member 30a and the second support member 30b, a first recess 38a and a second recess 38b used to support the ends of the casing 16 are formed respectively. In addition, the first support member 30a and the second support member 30b are joined to the casing main body 32 to form a supply path 44 used to supply coolant medium that passes through a coolant flow passage 22 of the heat sink 14 and a discharge path 46 used to discharge the coolant medium that has passed through the coolant flow passage 22.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a power conversion device in which a circuit board is interposed between a heat sink and a casing.

  In a vehicle using a motor as a driving source, such as an electric vehicle, a power conversion device is also mounted so as to control the motor. Here, the power conversion device includes a circuit board on which various electronic components including a semiconductor element such as an insulated gate bipolar transistor (IGBT) are provided. While the motor is energized, the electronic component is energized, and the electronic component, and thus the circuit board, is heated.

  When the circuit board becomes too hot, it becomes difficult for the electronic component to perform a predetermined function. Therefore, it is widely performed to configure the power conversion device including a heat sink for cooling the circuit board. For example, in Patent Document 1, a heat sink is brazed to a housing part obtained by press-molding an aluminum plate, the heat sink is sandwiched between the housing part and the top plate part, and a cooling medium is supplied to the heat sink. A cooling mechanism is disclosed in which a pipe part for brazing is joined by brazing. The top plate is also brazed to the housing.

  In order to perform brazing joining, it is necessary to heat-treat the temporary assembly of the cooling mechanism. For this reason, a material that does not melt or deform during heat treatment must be selected, which is complicated and complicated. In addition, since such a material is generally a metal material, it is not easy to reduce the weight of the power conversion device. Further, since it takes a long time to perform the heat treatment, it is not easy to improve the production efficiency.

  Therefore, as proposed in Patent Document 2, it is recalled that a coolant supply / discharge portion made of a resin material and provided with at least one of a supply pipe or a discharge pipe for a cooling medium is fitted to both ends of the heat sink. Is done. In this configuration, a seal ring that seals between the coolant supply / discharge portion and the end of the heat sink is provided, and a holding member that prevents the seal ring from being detached is attached to the coolant supply / discharge portion. According to the description of Patent Document 2, in this case, the refrigerant liquid supply / discharge portion can be assembled to the heat sink without performing brazing joining or the like.

JP 2014-179563 A Japanese Patent Laid-Open No. 2006-76644

  As particularly shown in paragraph [0018] and FIG. 3 of Patent Document 2, the refrigerant liquid supply / discharge section is configured by forming at least one of a supply pipe or a discharge pipe on a main body section that is a hollow body. It consists of one member. The hollow interior of the main body serves as a passage for cooling liquid supplied from the supply pipe or discharged from the heat sink to the discharge pipe.

  For this reason, the refrigerant liquid supply / discharge portion has a complicated shape. Further, in order to prevent the fitted heat sink from being detached, it is necessary to finish the heat sink and the coolant supply / discharge portion with high dimensional accuracy. For this reason, shaping is not easy. Moreover, as described above, two refrigerant liquid supply / discharge portions, two seal rings, and holding members are required in addition to the heat sink, and the number of parts increases. For this reason, there is a concern that the production cost is improved.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power converter capable of simplifying and reducing the weight of the configuration and reducing the production cost.

In order to achieve the above object, the present invention provides a circuit board on which electronic components are provided, a heat sink in which a refrigerant flow passage is formed through which a cooling medium for removing heat from the circuit board is formed, and the heat sink. In a power converter comprising a casing with the circuit board interposed therebetween,
The casing is
A support member made of a resin material and supporting the heat sink;
A casing body made of a resin material and holding the support member supporting the heat sink;
With
As the support member and the casing main body are joined to each other, a supply path for supplying the cooling medium to the refrigerant flow path from outside the casing to the casing, and from the refrigerant flow path to the outside of the casing And a discharge path for discharging the cooling medium.

  Thus, in the present invention, instead of forming the supply path and the discharge path only in one of the support member and the casing, the casing is configured by combining the support member and the casing body, and at the same time, A supply path for supplying the cooling medium to the heat sink and a discharge path for discharging the cooling medium flowing through the heat sink are formed. For this reason, the shapes of the support member and the casing body are simplified.

  The support member and the casing body having a simple shape can be easily formed (produced). Further, it is not necessary to finish the support member and the casing body with strict dimensional accuracy. For this reason, the operation | work which obtains a casing becomes simple and a casing can be manufactured efficiently.

  In addition, the casing can be constituted by the support member and the casing body. That is, it is possible to reduce the number of parts for obtaining the casing. This, combined with the use of a resin material as the material for the support member and the casing body, can reduce the weight of the casing and reduce the production cost of the power converter.

  In order to form the supply path and the discharge path, for example, a bottomed recess that is depressed from the side facing the casing body to support the end of the heat sink and a cooling medium that is in communication with the recess are circulated in the support member. What is necessary is just to provide the cover part which obstruct | occludes the said recessed part in a casing main body while forming a refrigerant path. In this configuration, the supply path and the discharge path are formed by closing the recess with the lid. That is, the supply path and the discharge path can be easily formed without adopting a complicated configuration.

  In addition, you may make it form in a support member the bottomed intermediate | middle channel | path which is depressed from the side which faces a casing main body, and continues to the said recessed part. In this case, the lid portion closes both the recess and the intermediate passage.

  In the supply passage, the cooling medium once flows into the intermediate passage before flowing from the refrigerant passage through the recess into the refrigerant flow passage. As a result, the flow velocity is reduced, and it becomes easy to distribute the cooling medium to each refrigerant flow passage. On the other hand, in the discharge passage, the cooling medium once flows into the intermediate passage before flowing into the refrigerant passage from the refrigerant flow passage through the recess. In other words, the intermediate passage serves as a pool portion that temporarily stores the cooling medium when a large amount of the cooling medium is led out from the refrigerant flow passage and is difficult to discharge from the refrigerant passage. For this reason, it is avoided that the distribution of the cooling medium becomes difficult.

  In this case, it is preferable that the refrigerant passage is formed as a through hole extending from the back surface of the support member facing the casing body to the bottom surface of the intermediate passage. Since the intermediate passage is opened on the side facing the casing body, it is easy to form a through hole extending in such a direction.

  Two support members may be provided, and the heat sinks may be supported by the respective recesses in a state where the two support members are separated from each other. In this case, since there is no site | part which covers a heat sink, the further weight reduction of a casing and by extension, a power converter device can be achieved. In addition, since a part of the heat sink is exposed from the casing, for example, the contact area with the atmosphere around the heat sink increases. For this reason, heat dissipation from the heat sink is efficiently performed.

  It is preferable that the casing body is configured to have an interposed part that interposes the circuit board together with the heat sink, and a protrusion that protrudes from the interposed part. For example, if a screw insertion hole is formed in this protrusion, it becomes easy to position and fix the power conversion device to a predetermined member constituting the power module unit or the like by the screw inserted through the screw insertion hole. Thus, by providing the protrusion, the power conversion device can be attached to a predetermined member while avoiding an increase in the number of parts.

  The joining of the support member and the casing body is preferably performed by bonding with an adhesive or welding. In this case, a heat treatment furnace is not required unlike the brazing joint. Therefore, it is possible to reduce the capital investment, and hence the production cost. Moreover, the concern that the casing made of the resin material is deformed or melted is eliminated.

  According to the present invention, as the casing is configured by combining the support member and the casing body, a supply path and a discharge path through which the cooling medium flows are formed in the casing. For this reason, since the shapes of the support member and the casing body are simplified, it is easy to produce the casing. In addition, for this reason, it is not necessary to finish the support member and the casing body with strict dimensional accuracy, so that the operation of obtaining the casing is simplified, and the casing can be manufactured efficiently.

  Furthermore, since a casing can be obtained with a support member and a casing main body, it is possible to reduce the number of parts which comprise a casing. In addition, the support member and the casing body are made of a resin material. For the reasons described above, the configuration of the casing, and thus the power converter, can be simplified, reduced in weight, and the production cost can be reduced.

1A and 1B are a schematic overall perspective view from above and a schematic overall perspective view from below of a power conversion device according to an embodiment of the present invention, respectively. It is a principal part disassembled perspective view of the power converter device shown to FIG. 1A and 1B. It is the principal part disassembled perspective view which showed the heat sink with which the supporting member was mounted | worn from the upper side, and showed the casing main body from the downward side. FIG. 4A is a vertical cross-sectional view of a main part in the vicinity of the supply path of the power conversion device, and FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a power conversion device according to the present invention will be given and described in detail with reference to the accompanying drawings. In the following, “left”, “right”, “lower” and “upper” correspond to the left, right, lower and upper of each drawing, but this is for convenience of understanding. However, it does not define the direction when the power converter is actually used.

  1A and 1B are a schematic overall perspective view from above and a schematic overall perspective view from below of a power conversion device 10 according to the present embodiment, respectively, and FIG. 2 is an exploded perspective view of a main part. The power conversion device 10 includes a circuit board 12, a heat sink 14 (see FIGS. 1B and 2) that sandwiches the circuit board 12, and a casing 16. In FIG. 2, the circuit board 12 is omitted, and the same applies to FIG.

  The circuit board 12 is provided with various electronic components 18 (elements) on an insulating substrate (substrate) on which conductive wiring is previously formed, thereby forming an electronic circuit. The electronic component 18 is, for example, a transistor such as an IGBT, a resistor, a capacitor, or a coil.

  The heat sink 14 is made of a metal material having good thermal conductivity, such as aluminum or an alloy thereof, and is obtained by extrusion molding or the like. In this case, the heat sink 14 is a flat hollow body in which a cross section perpendicular to the longitudinal direction forms a track shape, and a lower end surface and an upper end surface form a flat surface. In addition, a refrigerant flow in which a partition wall 20 (see FIG. 2) extends along the longitudinal direction and a cooling medium (for example, a cooling liquid such as cooling water) flows in a space formed by the adjacent partition walls 20. The road 22 becomes. That is, the heat sink 14 is made of a metal flat porous tube whose hollow interior is partitioned by a plurality of partition walls 20.

  In this case, the casing 16 includes a first support member 30a, a second support member 30b (that is, two support members), and a casing body 32. That is, in the present embodiment, the casing 16 includes three members 30a, 30b, and 32. The first support member 30a, the second support member 30b, and the casing body 32 are all made of a resin material. Preferable examples of this type of resin material include epoxy resin, acrylic resin, polysulfide resin and the like.

  As shown in FIGS. 2 and 3, the first support member 30 a includes a first support portion 34 a extending along the depth direction of the heat sink 14, and the longitudinal direction of the heat sink 14 from the first support portion 34 a. And a first tongue piece 36 a protruding so as to be separated from the heat sink 14. The depth of the first support portion 34a is slightly larger than the depth of the heat sink 14, and the direction along the longitudinal direction of the heat sink 14 is short.

  A first recess 38 a is formed in the first support portion 34 a so as to be recessed from the upper end surface side facing the casing body 32 toward the lower end surface side. For this reason, the 1st recessed part 38a becomes a bottomed shape which the upper end surface side opened. As will be described later, the right end of the heat sink 14 is supported by the first recess 38a.

  Similarly, the first tongue piece 36a is formed with a first intermediate passage 40a that is recessed from the upper end surface facing the casing body 32 toward the lower end surface and that is continuous with the first recess 38a. That is, the first intermediate passage 40a also has a bottomed shape with an upper end surface opened.

  The first tongue piece 36a is formed with a first through hole 42a extending linearly along the thickness direction of the first support member 30a from the lower end surface to the bottom surface of the first intermediate passage 40a. A cooling medium supply source (both not shown) is connected to the first through hole 42a via, for example, a pipe joint and a supply pipe. The cooling medium is supplied from the first through hole 42a to the first intermediate passage 40a. Thus, the first through hole 42a functions as a refrigerant passage through which the cooling medium supplied from outside the first support member 30a flows.

  The first recess 38a and the first intermediate passage 40a are closed by the casing body 32 as will be described later. As a result, the cooling medium flowing through the first through hole 42a is guided to the refrigerant flow passage 22 of the heat sink 14 through the first intermediate passage 40a and the first recess 38a. Thus, in the present embodiment, the first recess 38 a and the first intermediate passage 40 a are closed by the casing body 32, so that the cooling medium supply source provided outside the casing 16 is transferred to the refrigerant flow passage 22. And a supply path 44 (see FIG. 4A) for supplying the cooling medium.

  One second support member 30b has substantially the same shape as the first support member 30a, but for convenience of description, the names of the components corresponding to the components of the first support member 30a are replaced with “first”. “2” is added, and “b” is added instead of the subscript “a” of the reference sign. That is, the second support member 30b includes a second support portion 34b and a second tongue piece portion 36b. The second support portion 34b is formed with a bottomed second recess 38b having an upper end surface opened. The left end portion of the heat sink 14 is supported by the second recess 38b. The second tongue piece 36b is linearly extended from the lower end surface to the bottom surface of the second intermediate passage 40b, and has a bottomed second intermediate passage 40b that is continuous with the second recess 38b and opened at the upper end surface. Second through holes 42b are formed.

  For example, a cooling medium recovery tank (both not shown) is connected to the second through hole 42b via a pipe joint and a discharge pipe. The cooling medium is discharged from the second intermediate passage 40b through the second through hole 42b to the outside of the second support member 30b and is collected in the cooling medium collection tank. Thus, the second through hole 42b is a refrigerant passage through which the cooling medium discharged outside the second support member 30b flows.

  The second recess 38b and the second intermediate passage 40b are also closed by the casing body 32 (described later). Thereby, the cooling medium which circulated through the refrigerant flow passage 22 of the heat sink 14 is guided to the second through hole 42b through the second recess 38b and the second intermediate passage 40b. As can be understood from this, the cooling medium flowing through the refrigerant flow passage 22 is provided outside the casing 16 as the second recess 38b and the second intermediate passage 40b are closed by the casing body 32. A discharge path 46 (see FIG. 4B) for discharging to the cooling medium recovery tank is formed.

  The casing body 32 includes an interposition part 50 that interposes the circuit board 12 between the casing main body 32 and a protrusion 52 that protrudes from an outer edge part of the interposition part 50. The intervening part 50 is formed by forming a cross-shaped circuit pressing part 56 in a frame part 54. As shown in FIGS. 3, 4 </ b> A, and 4 </ b> B, the lower end surfaces of the frame portion 54 and the protrusion 52 are flush with each other, and thus the thickness of the frame portion 54 is larger than that of the protrusion 52. Further, the lower end surface of the circuit pressing portion 56 is located slightly above the lower end surface of the frame portion 54 as shown in FIGS. 4A and 4B.

  The protrusion 52 extends to a position overlapping the first support member 30a and the second support member 30b (see FIGS. 1A and 1B). As shown in FIGS. 3, 4A and 4B, the lower end surface of the protrusion 52 has a first rib 58a having a shape corresponding to the shape of the opening of the first recess 38a and the first intermediate passage 40a, and a second recess. 38b and a second rib 58b having a shape corresponding to the shape of the opening of the second intermediate passage 40b. As shown in FIG. 4A, the vicinity of the opening of the first recess 38a and the first intermediate passage 40a of the first support member 30a is joined to the lower end surface of the first rib 58a. Similarly, as shown in FIG. 4B, the vicinity of the opening of the second recess 38b and the second intermediate passage 40b of the second support member 30b is joined to the lower end surface of the second rib 58b.

  For this reason, the openings of the first recess 38 a, the first intermediate passage 40 a, the second recess 38 b, and the second intermediate passage 40 b are closed by the lower end surface of the protrusion 52. That is, the protrusion 52 functions as a lid that closes the first recess 38a, the first intermediate passage 40a, the second recess 38b, and the second intermediate passage 40b.

  A screw insertion hole 60 is formed in each of the first support member 30 a, the second support member 30 b, and the protrusion 52 of the casing body 32. The power conversion device 10 is positioned and fixed to a predetermined member via an attachment screw (not shown) passed through each screw insertion hole 60, and constitutes, for example, a power module unit that controls a motor mounted on an electric vehicle. To do.

  The power conversion device 10 according to the present embodiment is basically configured as described above. Next, the operation and effect will be described.

  The power converter 10 can be manufactured as follows. That is, first, the first support member 30a, the second support member 30b, and the casing body 32 are manufactured. For this purpose, for example, injection molding may be performed using a molten resin as a starting material. The first support member 30a and the second support member 30b can be manufactured by the same injection molding apparatus (mold). For this reason, capital investment can be reduced.

  In the first support member 30a, a first support portion 34a in which a first recess 38a is formed and a first tongue piece portion 36a in which a first intermediate passage 40a and a first through hole 42a are formed are integrally connected. Obtained as a single member. The first recess 38a and the first intermediate passage 40a open in the same direction, and the first through hole 42a extends along the thickness direction of the first support member 30a. It is easy to form such a shape by injection molding or the like. That is, by adopting the above-described shape, it becomes easy to produce the first support member 30a. Of course, the same applies to the second support member 30b.

  On the other hand, in another injection molding apparatus, a casing in which an interposition part 50 having a frame part 54 and a circuit pressing part 56 and a protrusion 52 provided with a first rib 58a and a second rib 58b are integrally connected. A main body 32 is produced. Thus, in this Embodiment, the 1st support member 30a which comprises the casing 16, the 2nd support member 30b, and the casing main body 32 consist of resin materials. Since the resin material is significantly lighter than a metal material having the same volume, the casing 16 and thus the power converter 10 can be effectively reduced in weight.

  Separately, the heat sink 14 is produced. As described above, the heat sink 14 can be obtained by subjecting a metal material having good thermal conductivity such as aluminum or an alloy thereof to extrusion molding or the like. At the time of extrusion molding, the partition wall 20 is also formed at the same time. That is, the heat sink 14 as a flat porous tube is obtained by performing the molding operation once.

  Further, an electronic component 18 such as a transistor such as an IGBT, a resistor, a capacitor, or a coil is mounted on an insulating substrate, and an electronic circuit is configured with a conductive wiring formed in advance on the insulating substrate. Thereby, the circuit board 12 is produced.

  Next, the support member is joined to the right end and the left end of the heat sink 14. Even if the support member is made of the same injection mold, the support member attached to the right end is the first support member 30a, and the support member attached to the left end is the second support member 30b. That is, in this case, support members having substantially the same shape are disposed at rotationally symmetric positions separated by approximately 180 °.

  Specifically, the right end of the heat sink 14 to which an adhesive has been applied in advance is inserted into the first recess 38a of the first support member 30a. Or you may make it apply | coat an adhesive agent to the bottom face of the 1st recessed part 38a, and the side surface facing the right end side of the heat sink 14. FIG. In either case, the adhesive is pressed by the heat sink 14 and spreads, closing the space between the bottom surface of the right end and the bottom surface of the first recess 38a and between the side of the right end and the side surface of the first recess 38a. By this blockage, a seal is made between the right end of the heat sink 14 and the first support member 30a.

  Further, the left end of the heat sink 14 to which an adhesive has been applied in advance is inserted into the second recess 38b of the second support member 30b. Instead of this, an adhesive may be applied to the bottom surface of the second recess 38 b and the side surface facing the left end side of the heat sink 14. In the same manner as described above, the adhesive spreads and closes between the bottom surface of the left end and the bottom surface of the second recess 38b, and between the left end side and the side surface of the second recess 38b. As a result, a seal is made between the left end of the heat sink 14 and the second support member 30b.

  Instead of joining with an adhesive, welding may be performed. In this case, heat and vibration may be applied to the bottom and side surfaces of the first recess 38a and the second recess 38b. In the former case, thermal welding is performed, and in the latter case, vibration welding is performed. In welding, the heat sink 14 and each of the first support member 30a and the second support member 30b are joined without a gap, and as a result, a seal is provided between the heat sink 14 and each of the first support member 30a and the second support member 30b. Is done.

  As shown in FIGS. 3 and 4A, it is preferable to form a clearance between the right tip surface of the heat sink 14 and the inner wall surface 62a of the first recess 38a facing the right tip surface. Similarly, as shown in FIGS. 3 and 4B, it is preferable to form a clearance between the second recess 38b and the inner wall surface 62b facing the left tip surface, as shown in FIGS. 3 and 4B. . 4A and 4B, the upper end surface of the heat sink 14 slightly protrudes from the upper end surfaces of the first support member 30a and the second support member 30b.

  Next, the circuit board 12 (see FIG. 1) is supported by the upper end surface of the heat sink 14, and in this state, the first support member 30a is joined to the lower end surface of the first rib 58a, and the lower end surface of the second rib 58b. The second support member 30b is joined to the joint. Thereby, while the 1st support member 30a and the 2nd support member 30b which supported the heat sink 14 are hold | maintained at the casing main body 32, the casing 16 is comprised and the power converter device 10 is obtained.

  At this time, the circuit board 12 is sandwiched between the heat sink 14 and the circuit pressing portion 56 (intervening portion 50) of the casing body 32. As described above, since the lower end surface of the circuit pressing portion 56 is located above the lower end surface of the frame portion 54, the upper end surface of the circuit board 12 accommodated in the frame portion 54 is the lower end surface of the circuit pressing portion 56. Abut.

  As described above, according to the present embodiment, the casing 16 can be constituted by the three members 30a, 30b, and 32. Therefore, the number of parts is reduced, the configuration is simplified, and the assembling work for obtaining the power converter 10 is facilitated. For this reason, the production efficiency of the power conversion device 10 can be improved and the production cost can be reduced.

  Moreover, in this case, the two support members are the first support member 30a and the second support member 30b. For this reason, the first support member 30a and the second support member 30b are separated from each other. The lower end surface is exposed from the casing 16. Therefore, since the contact area with the atmosphere is increased, heat dissipation is efficiently performed. In addition, the casing 16 can be further reduced in weight by the amount that does not cover the lower end surface of the heat sink 14.

  The joining of the first rib 58a and the first support member 30a and the joining of the second rib 58b and the second support member 30b are also performed by, for example, an adhesive or welding. When welding is performed, heat and vibration may be applied to the first rib 58a and the second rib 58b as described above. The first rib 58a surrounds the vicinity of the opening of the first recess 38a and the first intermediate passage 40a (see FIG. 4A), and the second rib 58b surrounds the vicinity of the opening of the second recess 38b and the second intermediate passage 40b. (See FIG. 4B). The lower end surface of the protrusion 52 closes the openings of the first recess 38a, the first intermediate passage 40a, the second recess 38b, and the second intermediate passage 40b, thereby forming the supply passage 44 and the discharge passage 46, respectively. Is done.

  Thus, by closing the opening of the first recess 38a, the first intermediate passage 40a, the second recess 38b, and the second intermediate passage 40b with the protrusion 52 provided in the casing body 32, the supply passage 44 and the discharge passage are provided. 46 can be formed. For this reason, after producing the 1st support member 30a, the 2nd support member 30b, and the casing main body 32, it is not necessary to perform the post-process for forming the supply path 44 and the discharge path 46. FIG. This also facilitates the work up to obtaining the power conversion device 10, thereby further improving the production efficiency of the power conversion device 10 and further reducing the production cost.

  In addition, since the supply path 44 and the discharge path 46 are formed as described above, the configuration of the first support member 30a and the second support member 30b can be simplified. Even if the heat sink 14, the first support member 30a, and the second support member 30b include design errors, the end portions of the heat sink 14 inserted into the first recess 38a and the second recess 38b are as described above. Thus, a seal is made between the two. For this reason, it is not particularly necessary to finish the heat sink 14, the first support member 30a, and the second support member 30b with strict dimensional accuracy.

  Therefore, the management items when producing the heat sink 14, the first support member 30a, and the second support member 30b are reduced. Accordingly, it becomes easy to produce the heat sink 14, the first support member 30a, and the second support member 30b.

  If necessary, the upper end surfaces of the right end and the left end of the heat sink 14 are joined to the lower end surface of the protrusion 52. When the adhesive is applied to the upper end surfaces of the right end and the left end of the heat sink 14, the adhesive develops and closes between the upper end surface and the lower end surface of the protrusion 52. Thereby, a seal is made. Or you may make it join the heat sink 14 and the protrusion 52 by welding.

  Thus, according to this Embodiment, the power converter device 10 can be comprised, without performing brazing joining. Therefore, the concern that the casing 16 made of a resin material is melted or deformed is eliminated.

  The power conversion device 10 manufactured as described above is positioned and fixed to a predetermined member via an attachment screw (not shown) passed through the screw insertion hole 60. Thereby, for example, a power module unit that controls a motor mounted on the electric automobile is configured.

  When the motor is energized, the electronic component 18 of the circuit board 12 is energized and a cooling medium (for example, cooling water) is supplied from the cooling medium supply source. This cooling medium is introduced into the supply path 44 through the supply pipe. That is, the cooling medium reaches the first intermediate passage 40a via the first through hole 42a. Since the volume of the first intermediate passage 40a is larger than that of the first through hole 42a, the cooling medium is temporarily stored in the first intermediate passage 40a and then flows into the first recess 38a.

  A clearance is preferably formed between the inner wall surface 62a of the first recess 38a facing the right tip surface of the heat sink 14 and the right tip surface. In this case, the cooling medium flowing into the first recess 38a diffuses within the clearance. For this reason, the cooling medium is distributed substantially evenly to each refrigerant flow passage 22 of the heat sink 14.

  The circuit board 12 is heated as the electronic component 18 is energized. This heat is transmitted to the cooling medium flowing through the refrigerant flow passage 22 in the heat sink 14 in contact with the lower end surface of the circuit board 12. And since the lower end surface of the heat sink 14 is exposed from the casing 16, the contact area with the air | atmosphere of the heat sink 14 is large. For this reason, so-called heat accumulation is prevented, and heat is efficiently released from the heat sink 14. In combination with the above, it is avoided that the temperature of the circuit board 12 rises excessively, and each electronic circuit exhibits a predetermined function.

  The cooling medium that has flowed through the refrigerant flow passage 22 is led to the second recess 38b. A clearance is preferably formed between the left end surface of the heat sink 14 and the inner wall surface 62b of the second recess 38b facing the left end surface. In this case, since the refrigerant flow passage 22 is avoided from being blocked by the inner wall surface, the cooling medium easily flows into the second recess 38b. The cooling medium is converged within the clearance, temporarily stored in the second intermediate passage 40b, and then discharged from the second through hole 42b.

  The cooling medium discharged from the second through hole 42b is recovered in the cooling medium recovery tank through the discharge pipe. The cooling medium is circulated and supplied to the supply path 44 after transferring the heat to the atmosphere or the like and becoming a low temperature.

  The present invention is not particularly limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

  For example, you may make it open the 1st through-hole 42a or the 2nd through-hole 42b to the 1st recessed part 38a or the 2nd recessed part 38b, without forming the 1st intermediate path 40a or the 2nd intermediate path 40b. Further, the first through hole 42 a or the second through hole 42 b may be formed so as to extend in a direction along the longitudinal direction of the heat sink 14.

  Further, both the supply path 44 and the discharge path 46 may be formed on either the first support member 30a side or the second support member 30b side. In this case, for example, the cooling medium supplied from the first support member 30a may be folded back by the second support member 30b and discharged from the first support member 30a. The opposite is true when the cooling medium is supplied from the second support member 30b.

  Further, the support member may be configured as a single member integrally including the first support portion 34 a and the second support portion 34 b and a portion covering the lower end surface of the heat sink 14. In this case, there is an advantage that the number of parts constituting the casing 16 is further reduced.

DESCRIPTION OF SYMBOLS 10 ... Power converter 12 ... Circuit board 14 ... Heat sink 16 ... Casing 18 ... Electronic component 22 ... Refrigerant flow path 30a, 30b ... Support member 32 ... Casing main body 34a, 34b ... Support part 36a, 36b ... Tongue piece part 38a, 38b ... Recesses 40a, 40b ... Intermediate passages 42a, 42b ... Through holes 44 ... Supply path 46 ... Discharge path 50 ... Interposition part 52 ... Protrusions 56 ... Circuit holding parts 58a, 58b ... Ribs

Claims (7)

A circuit board on which electronic components are provided; a heat sink in which a coolant flow path through which a cooling medium for removing heat from the circuit board is circulated; and a casing having the circuit board interposed between the heat sinks; In a power converter comprising:
The casing is
A support member made of a resin material and supporting the heat sink;
A casing body made of a resin material and holding the support member supporting the heat sink;
With
As the support member and the casing main body are joined to each other, a supply path for supplying the cooling medium to the refrigerant flow path from outside the casing to the casing, and from the refrigerant flow path to the outside of the casing And a discharge path for discharging the cooling medium. 2. The power conversion device according to claim 1, wherein the support member is depressed from a side facing the casing body to support the end of the heat sink, and a bottomed recess communicates with the recess to distribute the cooling medium. A refrigerant passage is formed,
In addition, the casing body is provided with a lid portion that closes the recess,
The power conversion device is characterized in that the supply path and the discharge path are formed as the lid portion closes the recess.   The power conversion device according to claim 2, wherein the support member is formed with a bottomed intermediate passage that is depressed from a side facing the casing main body and continues to the concave portion, and the lid portion closes the concave portion and the intermediate passage. The power converter characterized by doing.   4. The power conversion device according to claim 3, wherein the refrigerant passage is a through-hole extending from a back surface of the support member facing the casing body to a bottom surface of the intermediate passage. .   5. The power conversion device according to claim 2, wherein the support member is provided in two, and the heat sink is supported by each of the recesses in a state where the two support members are separated from each other. The power converter characterized by the above-mentioned.   The power conversion device according to any one of claims 2 to 5, wherein the casing body includes an interposed part that interposes the circuit board together with the heat sink, and a protrusion that protrudes from the interposed part. The power converter characterized by the above-mentioned.   The power converter according to any one of claims 1 to 6, wherein the support member and the casing main body are joined by adhesion or welding with an adhesive.

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