JP6636397B2 - Cooling fin structure - Google Patents

Description

  The present invention relates to a cooling fin structure, and more particularly to a cooling fin structure having columnar fins arranged in a staggered manner.

  Regarding a conventional cooling fin structure, Patent Literature 1 discloses a cooling fin structure provided with a pin fin having a circular cross section for cooling an electronic device.

  As disclosed in the above-mentioned patent documents, a cooler having pin fins disposed on a refrigerant passage is used to cool various electronic devices that generate heat. However, with the recent miniaturization of electronic devices, the heat flux of the electronic devices has increased, and there has been a demand for higher performance of coolers. Therefore, it is necessary to improve the performance of the cooling fin structure arranged in the cooler.

JP 2013-123038 A

  An object of the present invention is to solve the above-described problem, and to improve the efficiency of heat transfer from the columnar fins to the refrigerant in the cooling fin structure in which the columnar fins are arranged in a staggered manner.

  The present invention has the following aspects in order to achieve the above object.

  1) A cooling fin structure used for a cooler of an electronic device, comprising: a plurality of columnar fins arranged in a staggered manner in a refrigerant passage through which a refrigerant flows, wherein the columnar fins have one convex shape that is convex outward. The cylindrical fin has a fan-shaped cross-sectional shape composed of an arc and two concave arcs concaved inward, and the concave arc of the columnar fin is disposed adjacent to the columnar fin in an oblique direction on the concave arc side. The cooling fin structure located on the circumference centered on the center point of the convex arc.

  2) The convex arc has a radius R, the gap between the columnar fins disposed adjacent to each other in a direction orthogonal to the refrigerant flow is d, and is disposed adjacent to the refrigerant flow obliquely. The pitch between the columnar fins is R + d / 2 in a direction orthogonal to the flow of the refrigerant, and the radius of the circumference where the concave arc of the columnar fin is located is R + d. Cooling fin structure.

  3) The cooling fin structure according to the above 1) or 2), wherein a plurality of fin rows including a plurality of columnar fins arranged in the flow direction are provided.

  4) The cross-sectional shape of the columnar fin extends in the refrigerant flow direction and is line-symmetric with respect to a center line passing through the center of the columnar fin in a direction orthogonal to the refrigerant flow as one of the above 1) to 3). The cooling fin device according to any one of the above.

  5) The cooling fin structure according to 4) above, wherein a convex arc is arranged on an upstream side with respect to the flow direction, and a concave arc is arranged on a downstream side.

  6) The cooling fin structure according to 4) above, wherein a concave arc is arranged on an upstream side with respect to the flow direction, and a convex arc is arranged on a downstream side.

  As described above, according to the present invention, in the cooling fins in which the columnar fins are arranged in a staggered manner, the gap between the columnar fins arranged obliquely adjacent to the refrigerant flow is kept constant. As it is, the density of the columnar fins in the coolant flow direction can be increased. As a result, the efficiency of heat transfer from the columnar fins to the refrigerant can be improved.

It is the side view which omitted a part which shows the cooler of the power control unit to which the cooling fin structure by this invention was applied. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1 with a part omitted. It is a figure which expands and shows a part of FIG. FIG. 7 is a view corresponding to FIG. 2 and illustrating a cooling fin structure according to another embodiment of the present invention. It is a graph which compares the heat transfer coefficient per heat generation surface between the pin fins of circular cross section arranged in a zigzag shape and the outside of the columnar fin of the cooling fin structure of the present invention.

  An embodiment of the present invention will be described with reference to the drawings.

  In the drawings referred to below, the same or corresponding members have the same reference characters allotted.

  In the following description, the term “aluminum” includes an aluminum alloy in addition to pure aluminum.

In the present embodiment, the cooling fin structure according to the present invention is applied to a cooler of a power control unit (PCU) mounted on a hybrid vehicle. FIG. 1 is a side view showing a cooler of a power control unit to which a cooling fin structure according to an embodiment of the present invention is applied. FIG. 2 is a cross-sectional view when the cooler of the power control unit in FIG. 1 is viewed in a plan view. FIG. 3 is an enlarged view of a part of FIG.
Referring to FIG. 1, a plurality of semiconductor elements 12 to be cooled are mounted on a cooler 10 of a power control unit 1. The plurality of semiconductor elements 12 generate heat as the power control unit 10 is driven.

  1 and 2, the cooler 10 of the power control unit 1 has a cooling fin structure including an insulating plate 14, a flow path top plate 16, a flow path bottom plate 18, and a flow path side wall 24 and including a plurality of columnar fins 20. Have.

  The insulating plate 14 is formed of a material having high electrical insulation and thermal conductivity, for example, ceramics. On the surface of the insulating plate 14, a plurality of semiconductor elements 12 are joined at intervals.

  The flow path top plate 16, the flow path bottom plate 18, the flow path side walls 24, and the plurality of columnar fins 20 are formed of a material having high thermal conductivity. In the present embodiment, the channel top plate 16, the channel bottom plate 18, the channel side walls 24, and the plurality of columnar fins 20 are formed from aluminum. The channel top plate 16, the channel bottom plate 18, the channel side walls 24, and the plurality of columnar fins 20 constitute a heat sink that radiates heat generated in the semiconductor element 12 to cooling water (LLC: long life coolant) as a coolant. ing.

  As a method of manufacturing the cooler, a plurality of columnar fins 20 may be formed integrally with the channel top plate 16 or the channel bottom plate 18 by aluminum die casting, or a plurality of columnar fins 20 may be formed as a single unit. Thereafter, these may be assembled to the channel top plate 16 and the channel bottom plate 18. Alternatively, the columnar fins 20 may be formed integrally with one of the flow path top plate 16 and the flow path bottom plate 18 by forging and joined to the other.

  The cooling water passage 22 through which the cooling water flows is formed by combining the flow path top plate 16, the flow path bottom plate 18, and the flow path side wall 24 from all sides. An insulating plate 14 to which a plurality of semiconductor elements 12 are joined is joined to the channel top plate 16. The plurality of columnar fins 20 are arranged in the cooling water passage 22. The plurality of columnar fins 20 have a columnar shape extending in a rod shape, and are erected between the channel top plate 16 and the channel bottom plate 18 with an interval therebetween.

  The plurality of semiconductor elements 12 generate heat as the power control unit 10 is driven. Heat generated in the plurality of semiconductor elements 12 is transmitted to the plurality of columnar fins 20 through the insulating plate 14 and the channel top plate 16. On the other hand, cooling water is supplied to the cooling water passage 22 by an electric pump (not shown), and flows in one direction as indicated by an arrow 100 in FIG. During this time, heat generated between the plurality of semiconductor elements 12 is radiated by performing heat exchange between the cooling water and the plurality of columnar fins 20.

  In FIG. 2, the flow direction of the cooling water in the cooling water passage 22 is defined as an X-axis direction, and a direction orthogonal to the flow direction of the cooling water is defined as a Y-axis direction. The columnar fins 20 extend between the channel top plate 16 and the channel bottom plate 18 in a direction orthogonal to the X-axis direction and the Y-axis direction.

  The plurality of columnar fins 20 constituting the cooling fin structure are arranged in a staggered manner in the cooling water passage 22. That is, a plurality of columnar fins 20 arranged in a line in the X-axis direction (a plurality of columnar fins 20A arranged on the center line 110A in FIG. 2) and the plurality of columnar fins 20A are arranged in the X-axis direction next to the plurality of columnar fins 20A. The plurality of columnar fins 20B arranged in a line (the plurality of columnar fins 20B arranged on the center line 110B in FIG. 2) are arranged so as to be shifted from each other in the Y-axis direction (hereinafter, particularly the center line 110A). And the center line 110B is not distinguished.

  The columnar fins 20A in FIG. 2 and the columnar fins 20B arranged adjacent to the columnar fins 20A in a direction oblique to the flow direction of the cooling water (a direction between the X-axis direction and the Y-axis direction). Note that the columnar fins 20A and the columnar fins 20B are arranged at a pitch of Px in the X-axis direction and at a pitch of Py in the Y-axis direction.

  In the present embodiment, the plurality of columnar fins 20 are arranged so as to satisfy the relationship of Px> Py. Further, in the present embodiment, the size of the pitch Py is set such that a part of the columnar fin 20A overlaps with the columnar fin 20B when the columnar fin 20A is shifted by ＰPx in the X-axis direction.

  Subsequently, the structure of the columnar fin 20 used in the cooler 10 of the power control unit 1 in FIGS. 1, 2 and 3 will be described in detail. FIG. 3 is an enlarged view of a part of FIG.

  Referring to FIG. 3, columnar fin 20 has a fan-shaped cross-sectional shape when cut along an X-axis-Y-axis plane. More specifically, when cut along the X-Y-axis plane, the columnar fin 20 has only one convex arc 26 that is convex outward and two concave arcs 28 that are concave inward. Has a cross-sectional shape composed of

  The convex arc 26 has a radius R around a center point 102 located on the center line 110. The concave arc 28 is located on a circumference 130 centered on the center point 102 of the convex arc 26 of the columnar fin 20 which is arranged obliquely adjacent to the cooling water flow on the concave arc 28 side. The convex arc 26 is disposed on the upstream side in the refrigerant flow direction, and the concave arc 28 is also disposed on the downstream side. Here, assuming that a gap between the columnar fins 20 arranged adjacent to each other in the Y-axis direction orthogonal to the refrigerant flow is d, the protrusion of the columnar fins 20 arranged adjacently to the refrigerant flow in the oblique direction. The pitch Py in the Y-axis direction between the center points 102 of the arc 26 is R + d / 2, and the radius of the circumference 130 where the concave arc 28 of the columnar fin 20 is located is R + d. One end of the two concave arcs 28 intersects on the center line 110, and the other end of the two concave arcs 28 and both ends of the convex arc 26 intersect on one straight line extending in the Y-axis direction. Therefore, the cross-sectional shape of the columnar fin 20 is line-symmetric about the center line 110.

  In FIG. 2, the convex arc 26 of the columnar fin 20 is arranged on the upstream side in the flow direction of the cooling water, and the concave arc 28 is arranged on the downstream side. In contrast, FIG. As described above, the convex arc 26 may be arranged on the downstream side in the flow direction of the cooling water, and the concave arc 28 may be arranged on the upstream side.

  FIG. 5 shows an equivalent heat transfer coefficient to the cooling water obtained by using the columnar fins of the cooling fin structure of the present invention (Example) and an equivalent heat transfer coefficient to the cooling water obtained by using the pin fin having a circular cross section. It is a graph which compares with (comparative example).

  The pin fin in the comparative example is a columnar pin fin having the same radius (radius R) as the convex arc 26 of the columnar fin 20 of the cooling fin structure of the present invention, and is disposed adjacent to the coolant flow in the Y-axis direction. The pin fins are arranged in a staggered manner so that the gap between the pin fins and the pin fins arranged adjacent to the refrigerant flow in the oblique direction are d.

When the equivalent heat transfer coefficient from the fin to the cooling water was evaluated by CAE analysis, as shown in FIG. 5, the equivalent heat transfer coefficient of the example was 3000 W / m ² K higher than that of the comparative example.

  The configuration of the cooling fin structure according to the embodiment of the present invention described above will be described collectively. The cooling fin structure according to the present embodiment is used for the cooler 10 of the power control unit 1 as an electronic device. The cooling fin structure includes a plurality of columnar fins 20 arranged in a staggered manner in a cooling water passage 22 as a coolant passage through which cooling water as a coolant flows. The columnar fin 20 has a cross-sectional shape consisting of only one convex arc 26 and two concave arcs 28. The concave arc 28 has a circumference 130 centered on the center point 102 of the convex arc 26 of the columnar fin 20 disposed obliquely adjacent to the cooling water flow from the columnar fin 20 having the concave arc 28. It is located in.

  According to the cooling fin structure thus configured, in the cooler 10 of the power control unit 1 including the staggered columnar fins 20, it is possible to improve the efficiency of heat transfer from the columnar fins 20 to the cooling water. it can. Thereby, the cooling efficiency of the plurality of semiconductor elements 12 constituting the power control unit 1 can be improved.

  The present invention is applied to a cooler of a power control unit mounted on a fuel cell hybrid vehicle (FCHV) or an electric vehicle (EV: Electric Vehicle) using a fuel cell and a secondary battery as power sources. It can also be applied. In the hybrid vehicle according to the present embodiment, the internal combustion engine is driven at the fuel efficiency optimum operating point, whereas in the fuel cell hybrid vehicle, the fuel cell is driven at the power generation efficiency optimum operating point. The use of the secondary battery is basically the same for both hybrid vehicles.

  The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is mainly applied to a cooler for cooling a heating element such as a semiconductor element.

1: Power control unit 10: Coolers 20, 20A, 20B: Column fins 22: Refrigerant passage 26: Convex arc 28: Concave arc 102: Center points 110, 110A, 110B: Center line 130: Circumference

Claims (6)

  A cooling fin structure used for a cooler of an electronic device, comprising a plurality of columnar fins arranged in a staggered manner in a refrigerant passage through which a refrigerant flows, wherein the columnar fin has one convex arc that is convex outward. , And has a fan-shaped cross-sectional shape composed of two concave arcs that are concave inward, and the concave arcs of the columnar fins are convexes of the columnar fins disposed adjacent to the columnar fins in a diagonal direction on the concave arc side. Cooling fin structure located on the circumference centered on the center point of the arc.   The convex arc has a radius R, and the gap between the columnar fins arranged adjacently in a direction orthogonal to the refrigerant flow is d, and the columnar shape is arranged adjacent to the refrigerant flow obliquely. The cooling fin according to claim 1, wherein the pitch between the fins is R + d / 2 in a direction orthogonal to the coolant flow, and the radius of the circumference where the concave arc of the columnar fin is located is R + d. Construction. The cooling fin structure according to claim 1, wherein a plurality of fin rows including a plurality of columnar fins arranged in the direction of the refrigerant flow are provided. The cross-sectional shape of the columnar fin extends in the direction of the refrigerant flow and is line-symmetric with respect to a center line passing through the center of the columnar fin in a direction orthogonal to the refrigerant flow as an axis. 4. The cooling fin structure according to 1 . 5. The cooling fin structure according to claim 4, wherein a convex arc is arranged on the upstream side with respect to the direction of the refrigerant flow, and a concave arc is arranged on the downstream side. The cooling fin structure according to claim 4, wherein a concave arc is arranged on the upstream side with respect to the direction of the refrigerant flow, and a convex arc is arranged on the downstream side.

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