JP2004128439A

JP2004128439A - Heating element cooling device

Info

Publication number: JP2004128439A
Application number: JP2003028120A
Authority: JP
Inventors: Taichi Tanigawa; 谷川　太一
Original assignee: Fuji Electric FA Components and Systems Co Ltd
Current assignee: Fuji Electric FA Components and Systems Co Ltd
Priority date: 2002-08-07
Filing date: 2003-02-05
Publication date: 2004-04-22

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the mass and costs of a cooling device by obtaining the same cooling capability as that of a conventional device without increasing its radiation area. <P>SOLUTION: The heating element cooling device has heating elements 1a, 1b and 1c which are mounted on one surface of a base 2 and comb-shaped fins 3 which are formed on the other surface of the base 2 as shown in Fig.(b). A deflector 4 having at least one apex is provided between a bottom plate 5 parallel to the base 2 and tips of the fins 3. In this way, cooling fluid from a cooling fluid influx part or a suction part (left in Fig.(a))is deflected toward parts in contact with the fins 3 or its neighborhood and the cooling capability is improved by increasing the speed of the cooling fluid. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
この発明は放熱構造、特にパワートランジスタなどの高発熱量の電子部品を冷却するための発熱体冷却装置に関する。
【０００２】
【従来の技術】
従来、一般的な櫛形ヒートシンクを含む発熱体冷却装置は、例えば図９，１０に示すようにベース２の一方の面に発熱体１ａ，１ｂ，１ｃを接触させるかまたは定着させ、他方の面には被冷却体として発熱体１ａ，１ｂ，１ｃの発熱量に応じた放熱面積を有するプレートフィン３が立てられ、ロウ付けまたはカシメにより結合されている。ヒートシンク（ベースおよびフィン）の材質として、通常は冷却能力の高いアルミニウムまたはアルミニウム合金が用いられる。ベース２の側面には側面板７が、また、ベース２と面平行に底板６がそれぞれネジ止め等により取り付けられている。
【０００３】
また、図１１，１２のようにベース２をベース奥行き方向と平行な直線によって領域１，領域２に分割し、発熱体１ａ，１ｂ，１ｃ，１ｄ，１ｅ，１ｆを、冷却流体の流れ方向８に沿って領域１および領域２にそれぞれ１列ずつに配置し、領域１にある発熱体１ａ，１ｂ，１ｃの各発熱量の合計をＰ１、領域２にある発熱体１ｄ，１ｅ，１ｆの各発熱量の合計をＰ２とするとき、領域１と領域２の面積の比率（ｓ１：ｓ２）、およびベース横方向の比率（Ｗ１：Ｗ２）を発熱量の比率（Ｐ１：Ｐ２）に等しくなるようにする場合がある。なお、各領域の発熱体は、冷却流体の流れ方向８と平行な中心線に沿うように配置する。
【０００４】
いずれの場合も、冷却は、フィン間に向けて冷却流体を吹き付けるか、またはフィン間から冷却流体を吸い出す位置にファン（ファンは図示を省略されている）が設けられているので、冷却流体は流れの方向を示す矢印８の方向に流れ、このフィン間を流れる冷却流体により、ベース２およびプレートフィン３から放熱が行なわれることになる。
なお、以上のような発熱体冷却装置ではその性能向上、特に熱抵抗値を減少させるべく、冷却流体流入部から送り込まれる冷却流体を、フィンと接し発熱体を搭載するベース部分、またはその近傍に向けて冷却流体の流れを偏向させるためのルーバーを、フィンに形成するものがある（例えば、特許文献１参照）。
しかし、これは構造が複雑になるという難点がある。また、特許文献１のものでは、ルーバーを通りすぎた冷却流体がうずを巻いて分散するという現象が発生する。
【０００５】
【特許文献１】
特開２００１−１１８９７２号公報（第２頁、図１，図２）
【０００６】
【発明が解決しようとする課題】
また、上記いずれの発熱体冷却装置においても発熱体の発熱量が増加すると、対策の１つとしてフィンの放熱面積を大きくすることが行なわれるが、このようにすると質量，コストが増大すると言う問題がある。この点について、図９〜図１２を参照して説明する。
例えば、入力電圧４００Ｖ，容量７５ｋＷのインバータに用いる発熱体冷却装置の場合、図９のＡ２−Ａ２断面図を示す図１０（ａ）と図１１のＡ３−Ａ３，Ａ４−Ａ４断面図を示す図１２（ａ），（ｂ）のフィンの長さＬを４００ｍｍとし、また、図９のＢ２−Ｂ２断面図を示す図１０（ｂ）と図１１のＢ２−Ｂ２断面図を示す図１２（ｃ）のベース横幅Ｗおよびフィン高さｈ１をそれぞれ３３６ｍｍ，１００ｍｍとする。
【０００７】
さらに、フィン先端から底板間の距離ｈ４を５ｍｍ、フィンの厚さＴを０．８ｍｍ、フィンピッチＰを４ｍｍ、プレートフィン３の枚数を７６枚として、冷却流体の流路断面積Ｓを算出すると約２．９×１０^−２ｍ^２となる。
また、発熱体冷却装置の質量は、ベースの厚さＴｂを１１ｍｍ、底板６および側面板７の厚さを各１ｍｍとして、ベース２，プレートフィン３，底板６および側面板７の合計質量は、アルミニウムの比重が２．７ｇ／ｃｍ^３なので約１１ｋｇとなる。
したがって、この発明の課題は、質量，コストを増大させることなく冷却性能を向上させることにある。
【０００８】
【課題を解決するための手段】
このような課題を解決するため、請求項１の発明では、ベースの一方の面に発熱体を搭載しベースの他方の面に被冷却体であるフィンを配置した強制空冷式ヒートシンクを含む発熱体冷却装置において、
冷却流体の流路の前記ベースに面平行な底板と前記フィン先端との間に、少なくとも１つの頂点を持つデフレクターを設け、冷却流体流入部または吸込部からの冷却流体をフィンと接する部分またはその近傍に向けて偏向し、冷却流体の速度を高めることを特徴とする。
この請求項１の発明においては、前記発熱体が複数あるときは、デフレクター頂点の冷却流体流入部または吸込部からの設置位置を、各発熱体の発熱量の大小に応じて決定することができる（請求項２の発明）。
【０００９】
また、請求項３の発明では、ベースの一方の面にベース奥行き方向と平行な直線によって分割されたそれぞれの領域に少なくとも１つの発熱体を搭載し、ベースの他方の面に被冷却体であるフィンをベース奥行き方向と平行に配置した強制空冷式ヒートシンクを含む発熱体冷却装置において、
冷却流体の流路に、前記フィンに対して面平行な仕切り板と、この仕切り板によって分割された冷却流体の各流路の前記ベースに面平行な底板と前記フィン先端との間に少なくとも１つの頂点を持つデフレクターとを設け、冷却流体流入部または吸込部からの冷却流体をフィンと接する部分またはその近傍に向けて偏向し、冷却流体の速度を高めることを特徴とする。
この請求項３の発明においては、前記発熱体が、前記ベースのそれぞれの領域に複数ずつあるときは、デフレクター頂点の冷却流体流入部または吸込部からの設置位置を、冷却流体のそれぞれの流路で、各発熱体の発熱量の大小に応じて決定することができる（請求項４の発明）。
請求項３または４の発明においては、前記ベースのそれぞれの領域を、ベース面積の比率と発熱体の発熱量の比率が等しくなるように分割し、前記仕切り板を前記発熱体の発熱量の比率と冷却流体の流路断面積の比率を等しくするように設けることができる（請求項５の発明）。
【００１０】
【発明の実施の形態】
図１はこの発明の第１の実施の形態を示す斜視図であり、図２は同じくその断面図である。
図９，図１０に示す従来装置との相違点は、フィンの高さｈ１を低くした点、およびフィンの高さｈ１を低くしたことによってできた、フィン先端とベース２に面平行な底板６との間の空間にデフレクター４を設置した点にある。
【００１１】
デフレクター４は板状部材からなり、図２（ａ）に示すように少なくとも１つの頂点Ａを有する。フィン先端とデフレクター頂点Ａとの間に距離ｈ２（図２（ｂ）参照）のような隙間を設けるか、またはデフレクター頂点Ａをフィン先端に接触させ、フィン先端とデフレクター頂点Ａとの距離ｈ２を０としても良い。また、デフレクター頂点Ａの位置、つまり冷却流体流入部分または吸込部分からデフレクター頂点より底板へ降ろした垂線が交差する点までの距離Ｌ１（図２（ａ）参照）は、発熱体１ａ，１ｂ，１ｃの発熱が最も高い（大きい）ところに合わせて調整するようにする。
【００１２】
図３，図４は第１の発明と従来例とを比較して説明するための説明図である。
いま、発熱体１ａ，１ｂ，１ｃの各発熱量を同じとした場合、冷却流体流入部または吸込部からの距離（Ｘｍｍ）に対するベース温度は図３に示すように、風下に配置された発熱体１ａのところで最も高くなる。その温度上昇量は太実線で示すこの発明によるものの方が、細実線で示す従来例の場合よりも小さくなっており、これはデフレクターを設けたことによる効果を示すものと言える。これは、図２（ａ）に示すように、デフレクター４の頂点Ａを発熱体１ａの直下に配置することにより、冷却流体の流速を図４に示すように、発熱体１ａの直下で最も速くすることができるためと考えられる。このように、デフレクター４の配置を最適化することで、最も発熱が高い部分での冷却流体速度を速くすることができ、ベース温度を効率良く低減することができる。なお、図３，４の冷却流体流入部分または吸込部分からの距離Ｘは、図２（ａ），図１０（ａ）に示すＸと対応している。
【００１３】
従来例における冷却流体の流路断面積Ｓは上述のように約２．９×１０^−２ｍ^２であったが、この発明の実施例の断面を示す図２（ｂ）のように、フィンの高さｈ１を６０ｍｍ、フィン先端とデフレクター頂点Ａとの距離ｈ２を５ｍｍ、デフレクターの高さｈ３を４０ｍｍとした場合、デフレクターの頂点Ａを含む平面での流路断面積Ｓは約１．８２×１０^−２ｍ^２となる。
【００１４】
ここで、冷却流体の速度Ｖについて考える。
冷却流体の速度Ｖは、冷却流体の流量をＱ［ｍ^３／ｓ］、流路断面積をＳ［ｍ^２］として、
Ｖ［ｍ／ｓ］＝Ｑ［ｍ^３／ｓ］／Ｓ［ｍ^２］　　　　　　　　　　　…（１）
のように表わされる。したがって、フィンの高さｈ１を１００ｍｍから６０ｍｍに４０％低くすると、流路断面積も約４０％低減するので、上記（１）式の関係から冷却流体の速度Ｖを約１．６倍にすることができる。
【００１５】
また、既存のヒートシンクの特性から、フィンの高さｈ１を４０％低くした場合は熱抵抗が約１６％大きくなること、冷却流体の速度を約１．６倍とした場合は熱抵抗を約１５％に小さくできることが確認されている。このことから、熱抵抗を従来とほぼ同じにできることが分かる。さらに、従来の発熱体冷却装置の質量が約１１ｋｇであるのに対し、フィンの高さｈ１を４０％低くしたことで質量を約８ｋｇに低減することができ、その分コストも削減できる。
【００１６】
図５はこの発明の第２の実施の形態を示す斜視図であり、図６は同じくその断面図である。
図１１，図１２に示す従来装置との相違点は、仕切り板９を設置した点、フィンの高さｈ１を低くした点、およびフィンの高さｈ１を低くしたことによってできた、フィン先端とベース２に面平行な底板６との間の空間にデフレクター４，５を設置した点にある。
【００１７】
デフレクター４，５は板状部材からなり、図６（ａ），（ｂ）に示すように、少なくとも１つの頂点Ａ１，Ａ２を有する。フィン先端とデフレクター頂点Ａ１，Ａ２との間に距離ｈ２（図６（ｃ）参照）のような隙間を設けるか、またはデフレクター頂点Ａ１，Ａ２をフィン先端に接触させ、フィン先端とデフレクター頂点Ａ１，Ａ２との距離ｈ２を０としても良い。また、デフレクター頂点Ａ１，Ａ２の位置、つまり冷却流体流入部分からデフレクター頂点より底部へ下ろした垂線が交差する点までの距離Ｌ１，Ｌ２（図６（ａ），（ｂ）参照）は、図５に示す領域１，領域２のそれぞれの領域にある発熱体の発熱量が最も高い（大きい）ところに合わせて調整するようにする。仕切り板９は、ねじ止め等により底板６に取りつけられる。仕切り板９の代用として、プレートフィン３のうちの一枚を底板６に接するほどの長さにしても良い。
【００１８】
図７，図８は第２の発明と従来例とを比較して説明するための説明図である。いま、図５に示す領域１の発熱体１ａ，１ｂ，１ｃの各発熱量を同じとし、領域２に示す発熱体１ｄ，１ｅ，１ｆのうち１ｅの発熱量が１ｄ，１ｆに対して大きいものとした場合、冷却流体流入部または吸込部からの距離（Ｘｍｍ）に対するベース温度Ｔは、図７（ａ）に示す発熱体１ａ，１ｂ，１ｃでは風下に配置された発熱体１ａ、図７（ｂ）に示す発熱体１ｄ，１ｅ，１ｆでは１ｅのところでそれぞれ最も高くなる。その温度上昇量はいずれも、太実線で示すこの発明によるものの方が、細実線で示す従来例の場合よりも小さくなっており、これはデフレクターを設けたことによる効果を示すものと言える。これは、図６（ａ），（ｂ）に示すように、デフレクター４，５の頂点Ａ１，Ａ２をそれぞれ発熱体１ａ，１ｅの直下に配置することにより、冷却流体の流速を図８に示すように、発熱体１ａ，１ｅの直下で最も速くすることができるためと考えられる。このように、デフレクター４，５の頂点Ａ１，Ａ２の配置を最適化することで、最も発熱が高い部分での冷却流体速度を速くすることができ、ベース温度を効率良く低減することができる。なお、図７，８の冷却流体流入部分または吸込部分からの距離Ｘは、図６（ａ），（ｂ）、図１２（ａ），（ｂ）に示すＸと対応している。
【００１９】
図５，６のように仕切り板を設けた場合も、その仕切り板によって分割される各流路の断面積は変わるが、流路全断面積は同じであり、また、各流路での流速も上記（１）式のように、図１，２のように仕切り板を設けない場合と同じになる。したがって、フィンの高さｈ１を１００ｍｍから６０ｍｍに４０％低くすると、流路断面積も約４０％低減し、上記（１）式の関係から冷却流体の速度Ｖを約１．６倍にできるのも図１，２の場合と同様である。また、流速を約１．６倍とした場合に、熱抵抗を約１５％小さくできることから、熱抵抗を従来と同様にできること、さらには重量を低減できるのも図１，２の場合と同様なのは言うまでもない。
【００２０】
【発明の効果】
この発明によれば、放熱面積を大きくするためにフィンの高さを伸ばす空間であったフィン先端とベースに面平行な底板との間にできた空間に、冷却流体を偏向しフィンベース部分またはベース近傍での冷却流体の速度を速くするためのデフレクターを設けるようにしたので、フィンの放熱面積を変えることなく、発熱体冷却装置の熱抵抗を従来とほぼ同じに維持でき、装置質量およびコストを低減することができる。例えば、容量７５ｋＷ，入力電圧４００Ｖの電力変換装置においては、質量を従来のものより約３ｋｇ低減でき、コストが低減する。
【図面の簡単な説明】
【図１】この発明の第１の実施の形態を示す斜視図
【図２】この発明の第１の実施の形態を示す断面図
【図３】冷却流体流入部分からの距離に対するベース温度の関係について、第１の発明と従来例とを比較して説明するための説明図
【図４】冷却流体流入部分からの距離に対する冷却流体の速度の関係について、第１の発明と従来例とを比較して説明するための説明図
【図５】この発明の第２の実施の形態を示す斜視図
【図６】この発明の第２の実施の形態を示す断面図
【図７】冷却流体流入部分からの距離に対するベース温度の関係について、第２の発明と従来例とを比較して説明するための説明図
【図８】冷却流体流入部分からの距離に対する冷却流体の速度の関係について、第２の発明と従来例とを比較して説明するための説明図
【図９】第１の従来例を示す斜視図
【図１０】第１の従来例を示す断面図
【図１１】第２の従来例を示す斜視図
【図１２】第２の従来例を示す断面図
【符号の説明】
１ａ，１ｂ，１ｃ，１ｄ，１ｅ，１ｆ…発熱体、２…ベース、３…プレートフィン、４，５…デフレクター、６…底板、７…側面板、８…冷却流体の流れ方向、９…仕切り板。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a heat radiating structure, and more particularly to a heating element cooling device for cooling electronic components having a high calorific value such as a power transistor.
[0002]
[Prior art]
Conventionally, a heating element cooling device including a general comb-shaped heat sink has a heating element 1a, 1b, 1c contacted or fixed to one surface of a base 2 as shown in FIGS. A plate fin 3 having a heat radiating area corresponding to the amount of heat generated by the heating elements 1a, 1b, 1c is set up as a member to be cooled, and is connected by brazing or caulking. As a material of the heat sink (base and fin), aluminum or an aluminum alloy having a high cooling capacity is usually used. A side plate 7 is attached to the side surface of the base 2, and a bottom plate 6 is attached to the base 2 by screws or the like in parallel with the base 2.
[0003]
11 and 12, the base 2 is divided into a region 1 and a region 2 by a straight line parallel to the depth direction of the base, and the heating elements 1a, 1b, 1c, 1d, 1e, 1f are set in the flow direction 8 of the cooling fluid. Are arranged in a line in the area 1 and the area 2 along the line, and the sum of the heat generation amounts of the heating elements 1a, 1b, and 1c in the area 1 is P1, and the heating elements 1d, 1e, and 1f in the area 2 are each Assuming that the total heat generation amount is P2, the ratio of the area of the region 1 to the region 2 (s1: s2) and the ratio in the base horizontal direction (W1: W2) are equal to the ratio of the heat generation amount (P1: P2). In some cases. Note that the heating elements in each region are arranged along a center line parallel to the flow direction 8 of the cooling fluid.
[0004]
In any case, the cooling fluid is blown toward the space between the fins or a fan (the fan is not shown) is provided at a position where the cooling fluid is sucked out from between the fins. The cooling fluid flows in the direction of the arrow 8 indicating the direction of the flow, and heat is radiated from the base 2 and the plate fins 3 by the cooling fluid flowing between the fins.
In the heating element cooling device as described above, in order to improve the performance, particularly to reduce the thermal resistance value, the cooling fluid sent from the cooling fluid inflow portion is brought into contact with the fins at the base portion where the heating element is mounted, or in the vicinity thereof. There is one in which a louver for deflecting the flow of the cooling fluid toward the fin is formed in the fin (for example, see Patent Document 1).
However, this has the disadvantage that the structure is complicated. Further, in the case of Patent Document 1, a phenomenon occurs in which the cooling fluid that has passed through the louver winds up and disperses.
[0005]
[Patent Document 1]
JP 2001-118972 A (page 2, FIG. 1 and FIG. 2)
[0006]
[Problems to be solved by the invention]
Also, in any of the above-described heating element cooling devices, when the heat generation amount of the heating element increases, one of the measures is to increase the heat radiation area of the fins. However, this increases the mass and cost. There is. This point will be described with reference to FIGS.
For example, in the case of a heating element cooling device used for an inverter having an input voltage of 400 V and a capacity of 75 kW, FIG. 10A is a cross-sectional view of A2-A2 in FIG. 9 and FIG. 10 is a cross-sectional view of A3-A3 and A4-A4 in FIG. The length L of the fins in FIGS. 12 (a) and 12 (b) is 400 mm, and FIG. 10 (b) showing the B2-B2 sectional view of FIG. 9 and FIG. 12 (c) showing the B2-B2 sectional view of FIG. ), The base width W and the fin height h1 are 336 mm and 100 mm, respectively.
[0007]
Further, when the distance h4 between the fin tip and the bottom plate is 5 mm, the fin thickness T is 0.8 mm, the fin pitch P is 4 mm, and the number of the plate fins 3 is 76, the flow path cross-sectional area S of the cooling fluid is calculated. It is about 2.9 × 10 ⁻² m ² .
Further, the mass of the heating element cooling device is such that the thickness of the base is 11 mm, the thickness of the bottom plate 6 and the side plate 7 is 1 mm each, and the total mass of the base 2, the plate fins 3, the bottom plate 6 and the side plate 7 is Since the specific gravity of aluminum is 2.7 g / cm ³ , the weight is about 11 kg.
Therefore, an object of the present invention is to improve cooling performance without increasing mass and cost.
[0008]
[Means for Solving the Problems]
In order to solve such a problem, the invention according to claim 1 includes a heating element including a forced air cooling type heat sink in which a heating element is mounted on one surface of a base and fins to be cooled are arranged on the other surface of the base. In the cooling device,
A deflector having at least one apex is provided between a bottom plate parallel to the base of the flow path of the cooling fluid and the fin tip, and a portion or a portion of the fin that contacts cooling fluid from a cooling fluid inflow portion or a suction portion with the fin. It is characterized by being deflected toward the vicinity and increasing the speed of the cooling fluid.
According to the first aspect of the present invention, when there are a plurality of the heating elements, the installation position of the deflector apex from the cooling fluid inflow section or the suction section can be determined according to the magnitude of the heating value of each heating element. (Invention of claim 2).
[0009]
According to the third aspect of the present invention, at least one heating element is mounted on one surface of the base in each area divided by a straight line parallel to the depth direction of the base, and the other surface of the base is a cooled object. In a heating element cooling device including a forced air-cooled heat sink in which fins are arranged in parallel with the base depth direction,
A partition plate parallel to the fins in the flow path of the cooling fluid, and at least one partition plate between the bottom plate parallel to the base and the fin tip of each flow path of the cooling fluid divided by the partition plate. A deflector having two apexes, wherein the deflector deflects the cooling fluid from the cooling fluid inflow portion or the suction portion toward or near a portion in contact with the fin to increase the speed of the cooling fluid.
In the third aspect of the present invention, when a plurality of the heating elements are provided in the respective regions of the base, the installation positions of the apex of the deflector from the cooling fluid inflow portion or the suction portion are changed to the respective cooling fluid flow paths. Thus, it can be determined according to the magnitude of the calorific value of each heating element (the invention of claim 4).
In the invention according to claim 3 or 4, each of the regions of the base is divided such that a ratio of a base area and a ratio of a calorific value of a heating element are equal, and the partition plate is a ratio of a calorific value of the heating element. And the cooling fluid can be provided so as to make the ratio of the cross-sectional area of the cooling fluid equal (the invention of claim 5).
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a perspective view showing a first embodiment of the present invention, and FIG. 2 is a sectional view thereof.
The difference from the conventional device shown in FIGS. 9 and 10 is that the height h1 of the fin is reduced and the height h1 of the fin is reduced, and the bottom plate 6 is made plane-parallel to the fin tip and the base 2. Is that the deflector 4 is installed in the space between the two.
[0011]
The deflector 4 is made of a plate-like member and has at least one vertex A as shown in FIG. A gap such as a distance h2 (see FIG. 2B) is provided between the fin tip and the deflector vertex A, or the deflector apex A is brought into contact with the fin tip, and the distance h2 between the fin tip and the deflector vertex A is reduced. It may be set to 0. Further, the position of the deflector vertex A, that is, the distance L1 (see FIG. 2 (a)) from the cooling fluid inflow portion or the suction portion to the point where the perpendicular drawn from the deflector vertex to the bottom plate intersects is determined by the heating elements 1a, 1b, 1c. Adjust according to the place where the heat generation is highest (large).
[0012]
FIG. 3 and FIG. 4 are explanatory views for comparing and explaining the first invention and the conventional example.
Assuming that the heating values of the heating elements 1a, 1b, and 1c are the same, the base temperature with respect to the distance (X mm) from the cooling fluid inflow section or the suction section is, as shown in FIG. It is highest at 1a. The amount of temperature rise according to the present invention shown by the thick solid line is smaller than that of the conventional example shown by the thin solid line, which can be said to show the effect of the provision of the deflector. This is because, as shown in FIG. 2A, by arranging the vertex A of the deflector 4 immediately below the heating element 1a, the flow velocity of the cooling fluid is fastest immediately below the heating element 1a as shown in FIG. It is thought that it is possible. As described above, by optimizing the arrangement of the deflectors 4, the cooling fluid speed in the portion generating the highest heat can be increased, and the base temperature can be efficiently reduced. Note that the distance X from the cooling fluid inflow portion or the suction portion in FIGS. 3 and 4 corresponds to X shown in FIGS. 2 (a) and 10 (a).
[0013]
Although the flow channel cross-sectional area S of the cooling fluid in the conventional example was about 2.9 × 10 ⁻² m ² as described above, as shown in FIG. When the height h1 is 60 mm, the distance h2 between the fin tip and the deflector vertex A is 5 mm, and the height h3 of the deflector is 40 mm, the flow path cross-sectional area S in a plane including the deflector vertex A is about 1.82. × 10 ⁻² m ² .
[0014]
Here, the speed V of the cooling fluid will be considered.
The velocity V of the cooling fluid is represented by Q [m ³ / s] of the flow rate of the cooling fluid and S [m ² ] of the cross-sectional area of the flow path.
V [m / s] = Q [m ³ / s] / S [m ² ] (1)
It is represented as Therefore, if the height h1 of the fins is reduced by 40% from 100 mm to 60 mm, the cross-sectional area of the flow path is also reduced by about 40%, so that the velocity V of the cooling fluid is increased by about 1.6 times from the relationship of the above equation (1). be able to.
[0015]
Also, from the characteristics of the existing heat sink, when the height h1 of the fin is reduced by 40%, the thermal resistance increases by about 16%. When the speed of the cooling fluid is increased by about 1.6 times, the thermal resistance increases by about 15%. It has been confirmed that it can be reduced to%. From this, it can be seen that the thermal resistance can be made almost the same as the conventional one. Furthermore, while the mass of the conventional heating element cooling device is about 11 kg, the mass can be reduced to about 8 kg by reducing the height h1 of the fin by 40%, and the cost can be reduced accordingly.
[0016]
FIG. 5 is a perspective view showing a second embodiment of the present invention, and FIG. 6 is a sectional view thereof.
The difference from the conventional device shown in FIGS. 11 and 12 is that the partition plate 9 is installed, the fin height h1 is reduced, and the fin height h1 is reduced. The point is that the deflectors 4 and 5 are installed in a space between the base 2 and the bottom plate 6 that is plane-parallel to the base 2.
[0017]
The deflectors 4 and 5 are made of a plate-like member and have at least one vertex A1 and A2 as shown in FIGS. 6 (a) and 6 (b). A gap such as a distance h2 (see FIG. 6 (c)) is provided between the fin tip and the deflector vertices A1 and A2, or the deflector vertices A1 and A2 are brought into contact with the fin tip and the fin tip and the deflector vertices A1 and A2. The distance h2 to A2 may be set to 0. Further, the positions of the deflector vertices A1 and A2, that is, the distances L1 and L2 (see FIGS. 6A and 6B) from the cooling fluid inflow portion to the point where the perpendiculars drawn from the deflector vertices to the bottom cross each other are shown in FIG. Are adjusted according to the highest (larger) heating value of the heating element in each of the region 1 and the region 2 shown in FIG. The partition plate 9 is attached to the bottom plate 6 by screwing or the like. As a substitute for the partition plate 9, one of the plate fins 3 may be long enough to contact the bottom plate 6.
[0018]
FIGS. 7 and 8 are explanatory diagrams for comparing and explaining the second invention and the conventional example. Now, it is assumed that the heating values of the heating elements 1a, 1b, 1c in the area 1 shown in FIG. 5 are the same, and the heating value of the heating element 1e among the heating elements 1d, 1e, 1f shown in the area 2 is larger than 1d, 1f. 7A, the base temperature T with respect to the distance (X mm) from the cooling fluid inflow section or the suction section is the heating element 1a, 1b, 1c shown in FIG. In the heating elements 1d, 1e, and 1f shown in b), the temperature is highest at 1e. In each case, the amount of temperature rise is smaller in the case of the present invention shown by the thick solid line than in the case of the conventional example shown by the thin solid line, which can be said to show the effect of providing the deflector. This is because the flow velocities of the cooling fluid are shown in FIG. 8 by arranging the vertices A1 and A2 of the deflectors 4 and 5 directly below the heating elements 1a and 1e, respectively, as shown in FIGS. As described above, it is considered that the highest speed can be obtained immediately below the heating elements 1a and 1e. By optimizing the arrangement of the vertexes A1 and A2 of the deflectors 4 and 5, the speed of the cooling fluid in the portion where the heat generation is highest can be increased, and the base temperature can be efficiently reduced. The distance X from the cooling fluid inflow portion or the suction portion in FIGS. 7 and 8 corresponds to X shown in FIGS. 6 (a), 6 (b), 12 (a), 12 (b).
[0019]
When the partition plate is provided as shown in FIGS. 5 and 6, the cross-sectional area of each flow path divided by the partition plate changes, but the total cross-sectional area of the flow path is the same. The same applies to the case where the partition plate is not provided as shown in FIGS. Therefore, when the height h1 of the fins is reduced by 40% from 100 mm to 60 mm, the cross-sectional area of the flow path is also reduced by about 40%, and the velocity V of the cooling fluid can be increased by about 1.6 times from the relationship of the above equation (1). This is the same as in FIGS. Also, when the flow velocity is increased by about 1.6 times, the thermal resistance can be reduced by about 15%, so that the thermal resistance can be made the same as the conventional one, and the weight can be reduced as in the case of FIGS. Needless to say.
[0020]
【The invention's effect】
According to the present invention, the cooling fluid is deflected to a space formed between the fin tip and the bottom plate parallel to the base, which was a space for extending the height of the fin in order to increase the heat radiation area, and fin base portion or A deflector is provided to increase the speed of the cooling fluid near the base, so that the heat resistance of the heating element cooling device can be maintained almost the same as before, without changing the radiating area of the fins. Can be reduced. For example, in a power converter having a capacity of 75 kW and an input voltage of 400 V, the mass can be reduced by about 3 kg as compared with the conventional one, and the cost is reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a first embodiment of the present invention; FIG. 2 is a sectional view showing a first embodiment of the present invention; FIG. 3 is a relation of a base temperature with respect to a distance from a cooling fluid inflow portion; FIG. 4 is an explanatory diagram for explaining the first invention and the conventional example in comparison with each other. FIG. 4 compares the first invention and the conventional example with respect to the relationship between the distance from the cooling fluid inflow portion and the speed of the cooling fluid. FIG. 5 is a perspective view showing a second embodiment of the present invention. FIG. 6 is a sectional view showing a second embodiment of the present invention. FIG. 7 is a cooling fluid inflow portion. FIG. 8 is an explanatory diagram for explaining the relationship between the base temperature and the distance from the cooling fluid in comparison with the second invention and the conventional example. FIG. 8 shows the relationship between the distance from the cooling fluid inflow portion and the speed of the cooling fluid. Explanatory diagram for comparing and describing the invention of the present invention and the conventional example [ 9 is a perspective view showing a first conventional example. FIG. 10 is a cross-sectional view showing a first conventional example. FIG. 11 is a perspective view showing a second conventional example. FIG. 12 is a cross-sectional view showing a second conventional example. [Explanation of symbols]
1a, 1b, 1c, 1d, 1e, 1f: Heating element, 2: Base, 3: Plate fin, 4, 5: Deflector, 6: Bottom plate, 7: Side plate, 8: Flow direction of cooling fluid, 9: Partition Board.

Claims

In a heating element cooling apparatus including a forced air cooling type heat sink in which a heating element is mounted on one surface of a base and fins serving as a cooled object are arranged on the other surface of the base,
A deflector having at least one apex is provided between a bottom plate parallel to the base of the flow path of the cooling fluid and the fin tip, and a portion or a portion of the fin that contacts cooling fluid from a cooling fluid inflow portion or a suction portion with the fin. A heating element cooling device, wherein the heating element cooling device is deflected toward the vicinity to increase the speed of a cooling fluid.

The heat generation device according to claim 1, wherein when there are a plurality of the heating elements, an installation position of the deflector apex from a cooling fluid inflow section or a suction section is determined according to a magnitude of a heating value of each heating element. Body cooling device.

On one surface of the base, at least one heating element is mounted in each area divided by a straight line parallel to the base depth direction, and fins to be cooled are mounted on the other surface of the base in parallel with the base depth direction. In the heating element cooling device including the arranged forced air cooling type heat sink,
A partition plate parallel to the fins in the flow path of the cooling fluid, and at least one partition plate between the bottom plate parallel to the base and the fin tip of each flow path of the cooling fluid divided by the partition plate. A heating element cooling device comprising: a deflector having two vertexes; and deflects a cooling fluid from a cooling fluid inflow portion or a suction portion toward or near a portion in contact with a fin to increase the speed of the cooling fluid.

When there are a plurality of heating elements in each area of the base, the installation position of the deflector apex from the cooling fluid inflow section or the suction section is determined by the flow path of the cooling fluid in the amount of heat generated by each heating element. The heating element cooling device according to claim 3, wherein the heating element cooling device is determined according to the magnitude.

Each region of the base is divided so that the ratio of the base area and the ratio of the calorific value of the heating element are equal, and the partition plate is divided by the ratio of the calorific value of the heating element and the ratio of the cross-sectional area of the flow path of the cooling fluid. The heating element cooling device according to claim 3, wherein the heating element cooling device is provided so that