JP2008221951A - Cooling system of electronic parts for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling system of electronic parts for an automobile which is compact and exerts high cooling performance. <P>SOLUTION: In the cooling system of electronic parts for an automobile of the construction wherein a plurality of inner pipes 6 with a small diameter are inserted within an outer pipe 4 with a large diameter with an inverter 10 for the automobile being mounted on its outer face and are closely arranged, and a plurality of cooling units 2 are connected in series or in parallel; the outer peripheral faces of the inner pipes 6 in each cooling unit 2 are put in close contact with the inner peripheral face of the outer pipe 4 with the inner pipes 6 being inserted within and/or with the outer peripheral faces of the inner pipes 6 which closely contact with the inner peripheral face of the outer pipe 4, at least one flat face 8 for mounting the inverter 10 is provided on the outer peripheral face of the outer pipe 4, and cooling liquid is made circulate within the inner pipes 6 and in the entire space between these inner pipes 6 and the outer pipe 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an automobile electronic component cooling apparatus, and more particularly to an automobile electronic component cooling apparatus that can be suitably used as a cooler for an inverter or the like of a hybrid automobile or the like.

  In recent years, electric vehicles, fuel cell vehicles, hybrid vehicles, etc. have received attention as traffic / transportation systems that use electricity as a driving force instead of internal combustion engines due to soaring fuel in addition to environmental protection. Is configured to drive a motor using electric energy stored in a battery via an inverter to obtain power. Thus, in such a power output mechanism, a large current flows through the inverter device. Therefore, the heat generation of semiconductor elements such as IGBTs constituting the inverter device increases, so that it is cooled. In addition, a cooler having a large cooling capacity is required.

  For this reason, conventionally, various liquid-cooled coolers have been proposed in order to cool such a high heat density heating element. For example, in Japanese Patent Laid-Open No. 7-38025 (Patent Document 1), a cooling structure having a flat tube shape by combining a pair of comb-shaped cooling blocks is proposed. A metal having excellent conductivity, for example, a material formed by cutting copper is used. Moreover, in JP 2002-9216 A (Patent Document 2), a flat tube integrally formed by extrusion, which is a type generally used for condensers and evaporators of air conditioners, was used. A cooling fluid cooling type circuit device has been proposed. Furthermore, in Japanese Patent Application Laid-Open No. 2005-203732 (Patent Document 3), two metal plates made of aluminum or the like are processed by press molding, and the edges are joined to form a tube, A cooler having a structure in which corrugated fins made of aluminum or the like are arranged in the tube has been proposed. In each of these proposed cooling devices, a structure is adopted in which the heat generated from the semiconductor element attached to the outer surface of the tube is cooled by the coolant flowing through the inside of the tube. It is.

  By the way, in this kind of cooling device, it is desired to make it as compact as possible because space is limited at the time of installation, and the heat generated from the semiconductor element is increasingly increased in heat density. From now on, there is a need for further higher cooling performance, but the cooling devices that have been proposed so far respond to such requests for compactness and higher cooling performance. Various problems are inherent.

  For example, in a cooling device of the type disclosed in Patent Document 1 or Patent Document 3, a tube is formed by combining two parts. In other words, the reliability of the sealing performance of the joint becomes a problem. Specifically, in Patent Document 1, a structure in which an O-ring is attached to the outermost joint portion of the tube and screwed is employed, and in Patent Document 3, an edge portion of two plates is used. The target tube is completed by brazing, but the presence of a brazing joint in such a tube is a seal compared to that composed of an integral tube. In addition to being unfavorable, measures such as mounting an O-ring as a countermeasure against this increase the number of parts and increase costs in addition to fixing work using screws. The more compact the cooler, the greater the difficulty.

  Under such circumstances, a cooler of the type proposed in Patent Document 2 in which an integrally molded product is used is preferable. However, there is a problem that the cooling performance is limited when the cooler is made compact. Is inherent. In particular, in cooling applications for electronic circuit components such as inverters for automobiles, in addition to increasing the density of heating elements, it is necessary to make the cooler as compact as possible. While it is necessary to secure a large coolant flow path and also to sufficiently ensure the heat transfer surface of the coolant and the tube, it is not possible to sufficiently meet such a demand. That is, in the cooler of the type proposed in Patent Document 2, the cooling performance can be improved by making the inner wall of the tube as thin (thin) as possible and increasing the number thereof. Thus, it is not easy to form many thin inner walls in the small cross-sectional shape of the hollow tube.

  Moreover, when the tube material is aluminum or aluminum alloy with good extrudability, the hollow material can be extruded by porthole extrusion, but the small cross section and the complicated cross section as described above. Extrusion of the shape becomes extremely difficult, and when using copper or copper alloy with good thermal conductivity as the tube material, the hollow tube as described above is formed by extrusion It was almost impossible to do.

JP-A-7-38025 JP 2002-9216 A JP 2005-203732 A

  The present invention has been made in the background of such circumstances, and the problem to be solved is to provide an automotive electronic component cooling device that is compact and exhibits high cooling performance. is there.

  And, in the present invention, in order to solve such a problem, a plurality of thin inner pipes are interpolated with respect to a large outer pipe to which electronic circuit components are attached to the outer surface, Cooling device for automotive electronic parts having a structure in which a plurality of cooling units which are closely arranged and in which headers serving as coolant inflow / outflow ports are provided at both ends are connected in series or in parallel The outer peripheral surface of the inner tube in each cooling unit is on the inner peripheral surface of the outer tube in which the inner tube is inserted, and / or on the outer peripheral surface of the inner tube in close contact with the inner peripheral surface of the outer tube, The outer pipe is provided with at least one flat surface on which the electronic circuit component is mounted, and the entire gap between the inner pipe and the inner pipe and the outer pipe. It is configured to allow coolant to flow through A cooling device for electronic components for automobiles, characterized in, it is to its gist.

  In addition, according to a desirable aspect of the automotive electronic component cooling device according to the present invention, the inner tube is formed of a thinner tube than the outer tube.

  According to another desirable aspect of the automotive electronic component cooling device according to the present invention, each of the outer tube and the inner tube is made of copper or a copper alloy, and is further desirable. According to one aspect, the outer tube and the inner tube are each made of aluminum or an aluminum alloy.

  Accordingly, in the automotive electronic component cooling apparatus according to the present invention, the electronic circuit component as a heating element is attached to the flat surface provided on the outer peripheral surface of the outer tube constituting the cooling unit, Cooling is performed by circulating a coolant through the entire gap between the outer pipe and between the outer pipe and the inner pipe, and the inner pipe is placed in close contact with the outer pipe to which such electronic circuit components are attached. Therefore, the heat of the electronic circuit components with high heat density spreads to the entire tube wall of the outer tube by heat conduction, and heat is transferred from the tube wall of the outer tube to the tube wall of the inner tube. As a result, not only the inner surface of the outer tube but also the inner and outer surfaces of the inner tube also serve as heat transfer surfaces to the coolant, which effectively increases the heat transfer area to the coolant. As a result, a high cooling capacity can be exhibited.

  Moreover, such an electronic device cooling device for automobiles according to the present invention has an integrated structure in which a plurality of thin inner tubes are inserted into a large outer tube and are closely arranged. In addition, since it is not necessary to have a brazed joint or an O-ring mounting portion, the compactness can be advantageously realized. Also, in terms of structure, a small diameter is provided in a large-diameter outer tube. Forming a large number of inner walls to be heat transfer surfaces in a small cross-sectional shape without adopting a special operation such as extrusion, because a plurality of inner pipes are inserted and configured. However, it becomes possible easily.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

  First, FIG. 1 shows an embodiment of a cooling device for an automobile electronic component according to the present invention, as a perspective view thereof (a) and a plan view thereof (b). In this case, the cooling unit 2 has two flat surfaces 8 that are long and wide enough to mount two inverters 10 on the corresponding side surfaces, and a header 12 that serves as an inlet / outlet of the coolant. These are provided individually at both ends. Then, by connecting the corresponding headers 12 of the cooling units 2 with the connecting pipe 14 at the narrowed pipe-shaped tip portion 12b, the three cooling units 2, 2, and 2 are connected in series. It is a structure that is damped. Here, as is apparent from the drawing, the three cooling units 2, 2, and 2 are in a form in which the flat surfaces 8 face each other and are overlapped or folded at a predetermined interval. By being arranged, overall compactness as a cooling device for automobile electronic parts can be achieved.

  In the cooling unit 2, the individual headers 12, 12 provided at both ends thereof are flattened by two flat surfaces 8, 8 as shown in FIGS. 2 (a) and (b). It is configured separately or integrally with the outer tube 4 having an oval shape, and the cooling liquid introduced from one header 12 is formed in the inner tube or the inner tube of the cooling unit 2 as described later. The gap between the inner pipe and the outer pipe is circulated and discharged from the other header 12. Here, in FIG. 2, (a) shows an example in which a separate header 12 is attached to the cooling unit 2, in which an attachment having a shape corresponding to the outer shape of the outer tube 4 in the cooling unit 2 is shown. The parts 12a are respectively fitted to both ends of the cooling unit 2 and are liquid-tightly attached. On the other hand, the narrowed pipe-shaped tip part 12b is used as an inlet / outlet of the coolant, and the corresponding cooling is performed. The pipe 12 is connected to the pipe-shaped tip 12 b of the header 12 of the unit 2 via a connection pipe 14. Further, the header 12 shown in (b) is configured in an integrated structure with the cooling unit 2 in which the outer pipe 4 of the cooling unit 2 is narrowed and cooling liquid inflow / outflow ports (12b) are formed at both ends. ing.

  Further, the cooling unit 2 includes an outer tube 4 having a large-diameter, thick-walled oblong or rectangular shape, as is apparent from FIG. 3 showing a cross-sectional view perpendicular to the axis. And three inner tubes 6 that are housed in the outer tube 4 and have a thin and thin elliptical shape, and the three inner tubes 6 have their outer peripheral surfaces mutually connected to each other. Further, they are arranged in close contact with the inner peripheral surface of the outer tube 4. Moreover, the upper and lower outer peripheral surfaces of the outer tube 4 having a flat and substantially rectangular shape are flat surfaces 8 and 8, respectively, which are electronic circuit component mounting surfaces. All of the inside of the inner tube 6 (inside the tube) and the gap between the inner tube 6 and the outer tube 4 serve as a coolant flow path.

  In addition, as shown in FIG. 4 (a) or (b), the cooling unit 2 is provided on one of the upper and lower flat surfaces 8 and 8 provided on the outer peripheral surface of the outer tube 4, or In both cases, an inverter 10 to be cooled is attached and used.

  Therefore, in the cooling device for an automotive electronic component having a structure in which a plurality (three in this case) of the cooling units 2 having such a configuration are connected in series, the inverter 10 A plurality of (here, three) inner pipes 6 are introduced through the header 12 at the end from where they are inserted and arranged so as to be in close contact with the inner peripheral surface of the outer pipe 4 to which is attached. The coolant is allowed to flow in the gap between the inner tube 6 and the outer tube 4 along with the inside of the inner tube 6, and is thereby attached to the flat surface 8 of the outer tube 4. The heat of the high heat density of the inverter 10 spreads over the entire tube wall of the outer tube 4 by heat conduction and is transferred from the tube wall of the outer tube 4 to the tube wall of the inner tube 6. For this reason, not only the inner surface of the outer tube 4 but also the inner and outer surfaces of the inner tube 6 become heat transfer surfaces to the cooling liquid, and thus the heat transfer area to the cooling liquid. Can be effectively increased, and a high cooling capacity can be exhibited.

  In addition, the outer tube 4 and the inner tube 6 that also function as a heat transfer body of the heat from the inverter 10 constituting the cooling unit 2 are made of a material made of copper or copper alloy having good thermal conductivity. Thus, the cooling capacity of the cooling unit 2 is further improved.

  As described above, in the cooling unit 2 in the automotive electronic component cooling device according to the present invention, in order to transfer the heat of the inverter 10 from the outer tube 4 to the inner tube 6, the inner peripheral surface of the outer tube 4 and The outer peripheral surface of the inner tube 6 and further the outer peripheral surface of the inner tube 6 that is in close contact with the inner peripheral surface of the outer tube 4 need to be in thermal contact. In order to obtain easily, after inserting the inner pipe | tube 6 in the outer pipe | tube 4, an external force is applied to the outer wall surface of this outer pipe | tube 4, and the process of compressing and deforming the outer pipe | tube 4 is employ | adopted advantageously. The Rukoto. By adopting such a process and manufacturing the target cooling unit 2, a work such as brazing is not required, and a tube constituting the cooling unit 2 is formed only by simple compression deformation. Because you can. In this case, the means for applying an external force to the outer tube 4 and compressing and deforming it is not particularly limited. For example, a known means such as drawing or pressing with a diameter reducing die is appropriately employed. It is possible. Further, due to the compressive deformation of the outer tube 4, the inner tube 6 is also deformed, and as shown in FIGS. 3 and 4, the inner tube 6 is deformed into an elliptical shape, and the inner tube 6 and the outer tube are deformed. The closeness between the four can also be advantageously increased.

  Here, as the outer tube 4 for providing the cooling unit 2, it is possible to use a tube in which at least one flat outer peripheral surface (8) is formed in advance or a tube formed in a flat shape. In addition, as described above, by using a tube body having a simple circular cross-sectional shape, a flat surface 8 may be formed on the outer surface simultaneously with the inner tube 6 by applying an external force to the outer wall surface. Is possible. Further, as the inner tube 6, it is advantageous in terms of cost if a tube having a simple circular cross section is used. Even in the case where a tube having a simple circular cross section is used as the inner tube 6, in the manufacturing method as described above, an external force is applied to the outer wall surface of the outer tube 4 to compress and deform it as shown in FIG. 3. Thus, it becomes an elliptical shape.

  Further, as described above, when an external force is applied to the outer wall surface of the outer tube 4 to compress and deform it, the inner tube 6 is connected to the outer tube 4 from the outer tube 4 in order to improve the adhesion between the outer tube 4 and the inner tube 6. It is desirable that the inner pipe 6 used for this purpose be made to be preferentially deformed. As shown in FIG. 3, the inner pipe 6 has a thinner wall than the outer pipe 4, so that the resulting cooling unit can be obtained. The adhesion between the outer tube 4 and the inner tube 6 in 2 is improved.

  Note that the structure of the cooling unit 2 shown in the figure is only one of the typical embodiments of the present invention, which is merely an example, and the present invention relates to such an embodiment. It should be understood that this description is not to be construed as limiting in any way.

  For example, the number of the inner pipes 6 that are inserted into the outer pipe 4 and closely arranged is not limited to the three illustrated, but depends on the thickness of the outer pipe 4 and the inner pipe 6 that are used. An appropriate number is selected, and even in the arrangement form, not only one line but also a multi-stage arrangement form can be adopted as appropriate. In the embodiment shown in FIG. 5, 13 inner pipes 6 are closely arranged in the outer pipe 4 in a form in which the inner pipes 6 are alternately stacked in two upper and lower stages. Here, each inner tube 6 has a structure in which the inner tube 6 is in close contact with the inner peripheral surface of the outer tube 4.

  Even if the cooling units 2 are arranged in series, the number of the flat surfaces 8 provided in the cooling unit 2 and the size thereof are not limited to the three series arrangements as illustrated. Furthermore, an appropriate number of cooling units 2 are arranged in series according to the number of inverters 10 to be attached to such a flat surface 8, and even in the arrangement form. However, the present invention is not limited to the folded form as illustrated, and there is no problem even if it is a linear connection form.

  Furthermore, in the automotive electronic component cooling device according to the present invention, in addition to the series system shown in the schematic diagram of FIG. 7A in the example of FIG. 1, in the parallel system as shown in FIG. It is also possible to connect and configure a plurality of cooling units 2. That is, in FIG. 7B, the three cooling units 2 connect the respective inlets and outlets to the overall header 16 on the coolant inlet side and the overall header 18 on the coolant outlet side, respectively. The target cooling device is configured by being connected in parallel. Furthermore, in the present invention, as shown in FIG. 7 (c), a target cooling device can be configured by combining the serial method and the parallel method.

  In addition, in the above-described embodiment, the outer tube 4 and the inner tube 6 are configured using a material made of copper or a copper alloy having good thermal conductivity in order to improve the cooling capacity of the cooling unit 2. However, the constituent members of the outer tube and the inner tube can be configured by using a material made of aluminum or an aluminum alloy, so that not only good cooling capacity but also the cooling unit 2 can be formed. Can be manufactured at low cost.

  In addition, although not enumerated one by one, the present invention can be carried out in an embodiment to which various changes, modifications, improvements, etc. are added based on the knowledge of those skilled in the art. It goes without saying that any one of them falls within the scope of the present invention without departing from the spirit of the invention.

  Hereinafter, representative examples of the present invention will be shown to clarify the present invention more specifically, but the present invention is not limited by the description of such examples. It goes without saying.

Example 1
As shown in FIG. 3, a cooling unit 2 having a structure in which three inner pipes 6 are inserted and arranged in the outer pipe 4 was manufactured. That is, an outer tube 4 having a thickness of 2 mm and an inner tube 6 having a thickness of 1 mm, each made of phosphorous deoxidized copper, and three inner tubes 6 were inserted into the outer tube 4. Thereafter, it was pressed and formed into a rectangular flat shape as shown in FIG. 3 so that the outer tube 4 and the inner tube 6 were brought into close contact with each other, and a flat surface 8 on which a heat source (inverter 10) was installed was formed at the same time. . Note that the outer tube 4 formed in a rectangular flat shape has a width in the left-right direction in FIG. 3 of 50 mm and a thickness in the up-down direction of 15 mm.

The coolant flow path cross-sectional area in the cross section of the cooling unit 2 thus obtained is about 390 mm ² , and the cross-sectional space occupied by the cooling unit 2 is 750 mm ² (50 mm × 15 mm) at a ratio of 50% or more. It is secured. The area of the heat transfer surfaces, the length of the cooling unit 2: a 100mm per about ^{33000mm 2 (330mm 2 / mm)} . As a result, a compact and good cooling performance can be obtained.

-Comparative Example 1-
For comparison with the cooling unit 2 of Example 1, an extruded tube 20 having a three-hole structure as shown in FIG. 6A in the same cross-sectional area (50 mm × 15 mm; the same cross-sectional space is occupied) is made of an aluminum alloy. The three flow paths 24 extending in parallel to each other are provided by two of the inner walls 22 having a wall thickness of 2 mm. In addition, since such an extruded tube 20 cannot be extruded with copper or a copper alloy, it is manufactured here using an aluminum alloy.

The extruded tube 20 having the shape shown in FIG. 6A thus obtained has a cross-sectional area of the coolant flow path in the cross section of about 450 mm ² , and a cross-sectional space occupied by the cooling unit: 750 mm ² (50 mm × 15 mm) About 60%. Then, the area of the heat transfer surface, the cooling unit length: a 100mm per about ^{15000mm 2 (150mm 2 / mm)} .

  Therefore, the extruded tube 20 of Comparative Example 1 has a larger flow path cross-sectional area than the cooling unit 2 of Example 1, but the area of the heat transfer surface is remarkably reduced, so that the heat from the heating element is sufficient. It is recognized that the heat transfer is difficult and the cooling performance is inferior.

-Comparative Example 2-
A 7-hole aluminum alloy extruded tube 26 having a cross-sectional area similar to that of the extruded tube 20 of Comparative Example 1 as shown in FIG. 6B was obtained by extrusion. The wall thickness of the six inner walls 30 partitioning the seven flow paths 28 was 1.7 mm.

The cross-sectional area of the coolant flow path in the cross section of the obtained extruded tube 26 is about 390 mm ^2, which is equivalent to the cooling unit 2 of Example 1, but the area of the heat transfer surface is the cooling unit length: 100 mm. It is 22000 mm ² (220 mm ² / mm) per unit, which is about 2/3 of the cooling unit of Example 1, and it is recognized that the cooling capacity is inferior.

-Example 2-
A cooling unit 2 having a cross-sectional shape shown in FIG. 5 and having 13 inner tubes 6 inserted and arranged in two stages in the outer tube 4 was manufactured in the same manner as in Example 1. The outer tube 4 and the inner tube 6 were made of phosphorous deoxidized copper. The outer tube had a thickness of 2 mm and the inner tube had a thickness of 0.8 mm.

The cross-sectional area of the coolant flow path in the cross section of the cooling unit 2 thus obtained is about 320 mm ² , and is secured at a ratio of 40% or more with respect to the cross-sectional space occupied by the cooling unit: 750 mm ² (50 mm × 15 mm). ing. The area of the heat transfer surface, the cooling unit length: a per 100mm about ^{56000mm 2 (560mm 2 / mm)} , as compared to the cooling unit 2 of Example 1, although the flow path cross-sectional area decreases, Den It became clear that the area of the hot surface was large and the cooling performance was about 1.5 times.

It is explanatory drawing which shows an example of the cooling device of the electronic component for motor vehicles according to this invention, Comprising: (a) is the perspective explanatory drawing, (b) is the plane explanatory drawing. FIG. 2 is a perspective explanatory view showing a configuration of an end portion of a cooling unit in the automotive electronic component cooling device shown in FIG. 1, wherein (a) shows an example in which a separate header is attached, and (b) shows an integrated type. An example in which a header is provided is shown. It is a cross-sectional explanatory drawing which shows an example of the cooling unit in the cooling device of the electronic component for motor vehicles shown by FIG. It is sectional explanatory drawing which shows the example of attachment of the inverter with respect to the cooling unit shown by FIG. 3, (a) shows the example which attached one inverter, (b) shows the example which attached two inverter, respectively. Yes. It is sectional explanatory drawing which shows the example from which the cooling unit in the cooling device of the electronic component for motor vehicles according to this invention differs. It is sectional explanatory drawing which shows the example from which the extrusion tube which provides the conventional integrated cooling unit used in the comparative examples 1 and 2 differs, Comprising: (a) is the thing of the 3 hole type, (b) is the 7 Each hole type is shown. It is a schematic diagram which shows the example from which the cooling device of the electronic component for motor vehicles according to this invention differs, Comprising: (a) is an example of a series system (FIG. 1), (b) is an example of a parallel system, (c) is a series. An example in which a method and a parallel method are combined is shown.

Explanation of symbols

2 Cooling unit 4 Outer pipe 6 Inner pipe 8 Flat surface 10 Inverter 12 Header 12a Mounting part 12b Tip part 14 Connection pipe 16, 18 General header

Claims (4)

  A large-diameter outer tube to which electronic circuit components are attached to the outer surface is inserted with a plurality of small-diameter inner tubes closely arranged, and headers serving as coolant inflow / outlets are located at both ends. A plurality of cooling units provided in the above are connected to each other in series or in parallel. The electronic circuit component is in close contact with the inner peripheral surface of the inserted outer tube and / or the outer peripheral surface of the inner tube in close contact with the inner peripheral surface of the outer tube. An electronic device for automobiles, characterized in that at least one flat surface is provided to which the coolant is attached, and coolant is allowed to flow through the inner tube and the entire gap between the inner tube and the outer tube. Component cooling system.   The apparatus for cooling an electronic component for an automobile according to claim 1, wherein the inner tube is formed of a tube body thinner than the outer tube.   The said outer tube and the said inner tube are respectively comprised with copper or the copper alloy, The cooling device of the electronic component for motor vehicles of Claim 1 or Claim 2 characterized by the above-mentioned. The apparatus for cooling an automotive electronic component according to claim 1 or 2, wherein the outer tube and the inner tube are each made of aluminum or an aluminum alloy.

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