JP2012022947A

JP2012022947A - Cooling structure of lighting device

Info

Publication number: JP2012022947A
Application number: JP2010161217A
Authority: JP
Inventors: Takao Saito; 貴夫齋藤
Original assignee: Stanley Electric Co Ltd
Current assignee: Stanley Electric Co Ltd
Priority date: 2010-07-16
Filing date: 2010-07-16
Publication date: 2012-02-02

Abstract

PROBLEM TO BE SOLVED: To provide a cooling structure of a lighting device capable of improving brightness and lifetime by efficiently cooling a light-emitting section without causing enlargement and weight increase of the cooling structure and increase of power consumption.SOLUTION: In the cooling structure of a lighting device 1 wherein the light-emitting section 3 made of an LED substrate 5 where an LED as a light source is mounted and a base 6 for mounting the LED substrate 5, and a blower 4 fitted inside a case 2 for forcibly cooling the light-emitting section 3 by ventilating from a rear side of the light-emitting section 3, an air vent 7 is set in penetration at a central section of the base 6, and a plurality of ventilation grooves 8 are formed on a substrate mounting surface of the base 6. Further, the ventilation grooves 8 are formed in a radial shape with the air vent 7 as a center. Furthermore, a sum total of a contact area of the respective ventilation grooves 8 with the LED substrate 5 is set at 20-40% of an area of the LED substrate 5. The blower 4 is to be driven with a piezoelectric element.

Description

本発明は、ＬＥＤ（発光ダイオード）を光源とする発光部をブロアからの送風によって強制空冷する照明装置の冷却構造に関するものである。 The present invention relates to a cooling structure for an illuminating device that forcibly air-cools a light-emitting unit using an LED (light-emitting diode) as a light source by blowing air from a blower.

近年、消費電力が小さくて高寿命のＬＥＤを光源とする照明装置が増えてきつつあるが、照明装置に要求される照度を確保するためにはＬＥＤへの供給電流を増やす必要がある。このため、照明装置の光源として使用されるＬＥＤの消費電力が加速度的に上昇しており、これに伴って発光部の発熱量も増えている。 In recent years, lighting devices that use LEDs with low power consumption and long life as a light source are increasing. However, in order to secure the illuminance required for the lighting devices, it is necessary to increase the current supplied to the LEDs. For this reason, the power consumption of the LED used as the light source of the illuminating device is increasing at an accelerated rate, and the amount of heat generated by the light emitting unit is increased accordingly.

ＬＥＤの最大の問題点は、発光効率が向上しても、投入した電力の大部分が熱となり、発熱によって明るさと寿命が低下してしまうということである。特に、大電力のＬＥＤにおいては、チップ当たり数Ｗもの発熱に耐え得るだけのパッケージと放熱構造が求められており、熱伝導性に優れたメタルコア基板やセラミック基板が実用化されている。特に、セラミック基板については、材料技術の進歩によって熱伝導率が向上したこと、絶縁性の基板であるためにメタルコア基板とは違って絶縁層が不要であること等の理由から注目されている。 The biggest problem with LEDs is that even if the luminous efficiency is improved, most of the input power becomes heat, and the brightness and lifetime are reduced due to heat generation. In particular, high-power LEDs are required to have a package and a heat dissipation structure that can withstand heat generation of several watts per chip, and metal core substrates and ceramic substrates excellent in thermal conductivity have been put into practical use. In particular, ceramic substrates are attracting attention for reasons such as improved thermal conductivity due to advances in material technology and the fact that an insulating layer is unnecessary unlike a metal core substrate because it is an insulating substrate.

又、ＬＥＤの冷却手段として、従来はペルチェ素子による強制吸熱、ヒートシンクとファンによる強制空冷等（例えば、特許文献１参照）が採用されてきたが、大電力のＬＥＤの応用製品については、ＬＥＤの投入電力と発熱密度の増大に伴って、従来の冷却手段では冷却能力に限界が見え始め、より高い冷却能力を発揮する空冷ファンを用いた強制液冷システムを採用するものも出現している。 Conventionally, forced cooling by a Peltier element, forced air cooling by a heat sink and a fan, etc. have been adopted as cooling means for LEDs (see, for example, Patent Document 1). As the input power and the heat generation density increase, the cooling capacity of the conventional cooling means is beginning to appear, and some of them adopt a forced liquid cooling system using an air cooling fan that exhibits a higher cooling capacity.

特開２００８−１９８４７８号公報JP 2008-198478 A

しかしながら、特許文献１において提案されたＬＥＤ照明装置においては、空冷ファンを用いて効率良く熱交換するためには内蔵ヒートシンクが必要となり、ＬＥＤ照明装置の容積と重量の増加を招くという問題がある。又、空冷ファンは塵埃等の微粒子に対する耐久性が低いためにエアフィルタが必要となるが、エアフィルタを用いると吸入圧力が下がって送風と冷却能力の低下を招くために一層強力な空冷ファンが必要となり、消費電力が増加するという問題が発生する。 However, the LED lighting device proposed in Patent Document 1 requires a built-in heat sink in order to efficiently exchange heat using an air cooling fan, and there is a problem in that the volume and weight of the LED lighting device are increased. In addition, since the air cooling fan has low durability against fine particles such as dust, an air filter is required. However, if the air filter is used, the suction pressure is lowered and air blowing and the cooling capacity are lowered. The problem arises that it is necessary and power consumption increases.

本発明は上記問題に鑑みてなされたもので、その目的とする処は、大型化や高重量化、消費電力の増加を招くことなく、発光部を効率良く冷却して明るさと寿命の向上を図ることができる照明装置の冷却構造を提供することにある。 The present invention has been made in view of the above-mentioned problems, and its intended process is to improve the brightness and life by efficiently cooling the light emitting part without causing an increase in size, weight, and power consumption. An object of the present invention is to provide a cooling structure for a lighting device that can be realized.

上記目的を達成するため、請求項１記載の発明は、光源であるＬＥＤが実装されたＬＥＤ基板と該ＬＥＤ基板を載置するベースとから成る発光部と、該発光部の裏側から送風することによって発光部を強制空冷するブロアを筐体内に備えた照明装置の冷却構造として、前記ベースの中心部に通風孔を貫設し、該ベースの基板設置面と前記ＬＥＤ基板のベースへの設置面の少なくとも一方に複数の送風溝を形成したことを特徴とする。 In order to achieve the above object, the invention described in claim 1 is directed to a light emitting unit comprising an LED substrate on which an LED as a light source is mounted and a base on which the LED substrate is mounted, and blows air from the back side of the light emitting unit. As a cooling structure of an illuminating device provided with a blower forcibly air-cooling the light emitting part in the housing, a ventilation hole is formed through the center of the base, and the base board installation surface of the base and the LED board base installation surface A plurality of ventilation grooves are formed in at least one of the above.

請求項２記載の発明は、請求項１記載の発明において、前記送風溝を、前記通風孔を中心として放射状に形成したことを特徴とする。 According to a second aspect of the present invention, in the first aspect of the present invention, the air blowing groove is formed radially with the ventilation hole as a center.

請求項３記載の発明は、請求項１又は２記載の発明において、前記各送風溝の面積の総和を前記ＬＥＤ基板の面積に対して２０〜４０％に設定したことを特徴とする。 A third aspect of the invention is characterized in that, in the first or second aspect of the invention, the total sum of the areas of the air blowing grooves is set to 20 to 40% with respect to the area of the LED substrate.

請求項４記載の発明は、請求項１〜３の何れかに記載の発明において、前記ブロアとして圧電素子で駆動されるものを使用することを特徴とする。 According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the blower driven by a piezoelectric element is used.

請求項５記載の発明は、請求項１〜４の何れかに記載の発明において、前記各総風溝と同一直線上となる形状の送風溝を前記ベースの基板設置面から外側に位置する基板非設置面に向かって形成したことを特徴とする。 According to a fifth aspect of the present invention, there is provided the substrate according to any one of the first to fourth aspects, wherein the blower groove having a shape that is collinear with each of the total air grooves is located outside the substrate mounting surface of the base. It was formed toward the non-installation surface.

請求項１記載の発明によれば、ブロアによって発光部の裏側から送られる冷却風はベースの中心部に形成された通風孔から複数の送風溝を通って発光部のＬＥＤ基板とベースの間を流れ、その過程でＬＥＤ基板とベースを強制空冷するため、発光部が効率良く冷却されて照明装置の明るさと寿命が高められる。又、コンパクトで実用的な筐体放熱構造をそのまま活かした強制空冷方式を採用するため、筐体の側面や内部にヒートシンクを付加する必要がなく、筐体の容積を小さく抑えて照明装置の小型化と軽量化を図ることができる。 According to the first aspect of the present invention, the cooling air sent from the back side of the light emitting unit by the blower passes between the LED board of the light emitting unit and the base through the plurality of ventilation grooves from the ventilation holes formed in the center of the base. Since the LED substrate and the base are forcibly air-cooled in the process, the light emitting part is efficiently cooled, and the brightness and life of the lighting device are increased. In addition, the forced air-cooling system that utilizes the compact and practical case heat dissipation structure as it is, eliminates the need to add a heat sink to the side or inside of the case, minimizing the volume of the case and reducing the size of the lighting device. And weight reduction can be achieved.

請求項２記載の発明によれば、ブロアからの冷却風はベースの通風孔から放射状の送風溝に沿ってＬＥＤ基板とベースの間を均一に流れてこれらのＬＥＤ基板とベースを全体的に均一に冷却するため、発光部が効率良く冷却されて該発光部の明るさと寿命が高められる。特に、各送風溝を曲線状にすると、該送風溝の長さが長くなって冷却風が流れる時間も長くなり、冷却風量が増えるとともに、冷却風が旋回流となってＬＥＤ基板とベースの間を流れるため、この冷却風によってＬＥＤ基板とベースが一層効率良く冷却される。 According to the second aspect of the present invention, the cooling air from the blower flows uniformly between the LED substrate and the base along the radial air blowing groove from the ventilation hole of the base, and the LED substrate and the base are uniformly uniform. Therefore, the light emitting part is efficiently cooled, and the brightness and life of the light emitting part are increased. In particular, if each air groove is curved, the length of the air groove increases and the time for which the cooling air flows also increases, the amount of cooling air increases, and the cooling air becomes a swirl flow between the LED substrate and the base. Therefore, the LED substrate and the base are more efficiently cooled by this cooling air.

請求項３記載の発明によれば、各送風溝の面積の総和をＬＥＤ基板の面積に対して２０〜４０％に設定したため、発光部の冷却に必要十分な冷却風の流量を確保しつつ、ＬＥＤ基板からベースへの熱伝導を確保して発光部を効率良く冷却することができる。因みに、各送風溝の面積の総和がＬＥＤ基板の面積に対して２０％未満である場合には、送風溝を流れる冷却風の流量が不足するため、強制空冷による発光部の冷却効果が低減する。又、逆に各送風溝の面積の総和がＬＥＤ基板の面積に対して４０％を超えると、ＬＥＤ基板のベースへの接触面積が不足するためにＬＥＤ基板からベースへの熱伝導量が不足し、発光部の冷却効果が低減する。 According to invention of Claim 3, since the sum total of the area of each ventilation groove was set to 20 to 40% with respect to the area of a LED board, securing the flow volume of the cooling air required and sufficient for cooling of a light emission part, The light-emitting portion can be efficiently cooled by ensuring heat conduction from the LED substrate to the base. Incidentally, when the total area of the air blowing grooves is less than 20% with respect to the area of the LED substrate, the cooling air flow through the air blowing grooves is insufficient, so that the cooling effect of the light emitting part by forced air cooling is reduced. . Conversely, if the total area of the air blowing grooves exceeds 40% of the area of the LED board, the area of contact with the base of the LED board is insufficient, and the amount of heat conduction from the LED board to the base is insufficient. The cooling effect of the light emitting part is reduced.

請求項４記載の発明によれば、ブロアとして圧電素子によって駆動されものを使用するため、軸流ファンとは違って高い駆動圧力が得られ、エアフィルタの付加によってもブロアの吸入圧力や送風性能の低下を招くことがなく、ブロアの消費電力を低く抑えることができる。 According to the invention described in claim 4, since a blower driven by a piezoelectric element is used, a high driving pressure is obtained unlike an axial fan, and the suction pressure and blowing performance of the blower can be obtained even by adding an air filter. Without lowering the power consumption of the blower.

請求項５記載の発明によれば、各総風溝と同一直線上となる形状の送風溝をベースの基板設置面から外側に位置する基板非設置面に向かって形成したため、各送風溝を流れる空気の流れがスムーズになり、一層高い放熱効果が得られる。 According to invention of Claim 5, since the ventilation groove of the shape which becomes the same straight line as each total wind groove was formed toward the board | substrate non-installation surface located outside from the board | substrate installation surface of a base, it flows through each ventilation groove | channel. The flow of air becomes smooth, and a higher heat dissipation effect is obtained.

本発明に係る冷却構造を備える照明装置要部の分解斜視図である。It is a disassembled perspective view of the principal part of an illuminating device provided with the cooling structure which concerns on this invention. 本発明に係る冷却構造を示す発光部とブロアの分解斜視図である。It is a disassembled perspective view of the light emission part and blower which show the cooling structure which concerns on this invention. 本発明に係る冷却構造における冷却風の流れを示す発光部の断面図である。It is sectional drawing of the light emission part which shows the flow of the cooling air in the cooling structure which concerns on this invention. （ａ）は本発明に係る冷却構造を示すベースの平面図、（ｂ）は比較例１に係る冷却構造を示すベースの平面図である。(A) is a top view of the base which shows the cooling structure which concerns on this invention, (b) is a top view of the base which shows the cooling structure which concerns on the comparative example 1. FIG. 本発明と比較例１，２に係る冷却構造による冷却効果を示す図である。It is a figure which shows the cooling effect by the cooling structure which concerns on this invention and the comparative examples 1 and 2. FIG.

以下に本発明の実施の形態を添付図面に基づいて説明する。 Embodiments of the present invention will be described below with reference to the accompanying drawings.

図１は本発明に係る冷却構造を備える照明装置要部の分解斜視図、図２は本発明に係る冷却構造を示す発光部とブロアの分解斜視図、図３は本発明に係る冷却構造における冷却風の流れを示す発光部の断面図である。 FIG. 1 is an exploded perspective view of a main part of a lighting device having a cooling structure according to the present invention, FIG. 2 is an exploded perspective view of a light emitting unit and a blower showing the cooling structure according to the present invention, and FIG. It is sectional drawing of the light emission part which shows the flow of cooling air.

本実施の形態に係る照明装置１は、図１に示すように、一端が開口する略円筒状の筐体２の内部に発光部３と、該発光部３の裏側から送風することによって発光部３を強制空冷するブロア４（図２及び図３参照）を収容して構成されている。ここで、筐体２は耐熱性樹脂や表面がアルマイト加工されたアルミニウム等によって構成されており、閉じられた端部（図１の下端）には不図示のソケットに螺着される口金部２ａが形成されている。 As shown in FIG. 1, the lighting device 1 according to the present embodiment has a light emitting unit 3 and a light emitting unit by blowing air from the back side of the light emitting unit 3 inside a substantially cylindrical casing 2 having one end opened. A blower 4 (see FIGS. 2 and 3) for forcibly air-cooling 3 is accommodated. Here, the housing 2 is made of heat-resistant resin, aluminum whose surface is anodized, or the like, and a base 2a that is screwed into a socket (not shown) at a closed end (lower end in FIG. 1). Is formed.

上記発光部３は、光源である不図示のＬＥＤが実装された薄い矩形平板状のＬＥＤ基板５と、該ＬＥＤ基板５を載置固定する円板状のベース６とで構成されており、ベース６の上面（基板設置面）にはＬＥＤ基板５が嵌め込まれる矩形の浅い窪み６ａが形成されている。 The light emitting unit 3 includes a thin rectangular plate-shaped LED substrate 5 on which an LED (not shown) that is a light source is mounted, and a disk-shaped base 6 on which the LED substrate 5 is placed and fixed. A rectangular shallow recess 6a into which the LED substrate 5 is fitted is formed on the upper surface 6 (substrate mounting surface).

ところで、本実施の形態に係る照明装置１は、照明用の白色光線を出射するため、光源として青色ＬＥＤと黄色蛍光体とを組み合わせたものが使用されている。尚、光源として蛍光体を抜いた単色光源を用いることもできる。 By the way, since the illuminating device 1 which concerns on this Embodiment radiate | emits the white light for illumination, what combined blue LED and yellow fluorescent substance as a light source is used. In addition, a monochromatic light source from which a phosphor is removed can be used as the light source.

前記ＬＥＤ基板５としては種々の材質のものを使用することができるが、ＬＥＤの実装容易性と熱伝導の観点からセラミック基板や絶縁層付きのアルミニウム基板が好適である。本実施の形態では、光源として複数のＬＥＤを直列又は並列接続して成るマルチチップ構成のものが使用されており、図示しないが、ＬＥＤ基板５上には配線のための銅やアルミニウム等から成るパターンが形成されている。又、ＬＥＤとＬＥＤ基板５との接合方式としても種々のものを用いることができるが、ＬＥＤの実装容易性と熱伝導の観点からＡｕＳｎ共晶接合やＡｕバンプ接合が好適である。 The LED substrate 5 can be made of various materials, but a ceramic substrate or an aluminum substrate with an insulating layer is preferable from the viewpoint of LED mounting ease and heat conduction. In the present embodiment, a multi-chip configuration in which a plurality of LEDs are connected in series or in parallel is used as a light source. Although not shown, the LED substrate 5 is made of copper or aluminum for wiring. A pattern is formed. Various methods can be used for joining the LED and the LED substrate 5, but AuSn eutectic bonding and Au bump bonding are preferable from the viewpoint of LED mounting ease and heat conduction.

ＬＥＤ基板５を載置固定する前記ベース６の材質としては種々のものが使用できるが、加工性と熱伝導の観点から銅やアルミニウム等の熱伝導率の高い金属材料が好適であり、本実施の形態では、軽量であることからアルミニウムが使用されている。又、ベース６の厚みについては、薄過ぎると熱伝導性が悪くなって冷却効果が低下し、逆に厚過ぎると重量増加を招くため、ベース６の厚みとしては２〜５ｍｍ程度が最適である。尚、本実施の形態では、ベース６の厚みを３ｍｍに設定した。 Various materials can be used for the base 6 on which the LED substrate 5 is placed and fixed, but metal materials having high thermal conductivity such as copper and aluminum are preferable from the viewpoint of workability and heat conduction. In this form, aluminum is used because it is lightweight. As for the thickness of the base 6, if the thickness is too thin, the thermal conductivity is deteriorated and the cooling effect is lowered. On the other hand, if the thickness is too thick, the weight is increased. . In the present embodiment, the thickness of the base 6 is set to 3 mm.

前述のようにベース６の基板設置面である上面にはＬＥＤ基板５が嵌め込まれる矩形の窪み６ａが形成されているが、この窪み６ａの中心部には円孔状の通風孔７が上下方向に貫設されている。又、ベース６の基板設置面（上面）には、通風孔７から径方向外方へと窪み６ａの外側まで旋回しながら放射状に延びる複数の送風溝８が螺旋状に形成されている。詳細には、図１、図２及び図４（ａ）に示すように、複数の送風溝８がベース６の窪み６ａの外側である基板非設置面に延出するように送風溝８ａが形成されており、この送風溝８ａを形成することによって各送風溝８，８ａを流れる空気の流れがスムーズとなって、より一層高い放熱効果が得られる。本実施の形態では、送風溝８，８ａは曲線状に形成され、全体として通風孔７を中心として一回転方向（図１及び図２の時計回転方向）に旋回する螺旋形状を形成している。尚、送風溝８が描く軌跡については特に定めはないが、余り複雑に曲げると冷却風の流動抵抗が大きくなって流速が下がり、冷却性能の低下を招く。又、逆に送風溝８（８ａ）が描く軌跡が直線のように単純過ぎると、該送風溝８（８ａ）を流れる空気のＬＥＤ基板５との接触面積が小さくなり、送風溝８（８ａ）を流れる冷却風とＬＥＤ基板５及びベース６との熱交換量が減少し、ＬＥＤ基板５とベース６の冷却効果が低減する。 As described above, a rectangular recess 6a into which the LED substrate 5 is fitted is formed on the upper surface, which is the substrate installation surface of the base 6, and a circular vent hole 7 is formed in the vertical direction at the center of the recess 6a. It is penetrated by. In addition, a plurality of blowing grooves 8 that extend radially from the ventilation hole 7 to the outside of the recess 6a are formed in a spiral shape on the substrate installation surface (upper surface) of the base 6. Specifically, as shown in FIGS. 1, 2, and 4 (a), the air blowing grooves 8 a are formed so that the plurality of air blowing grooves 8 extend to the substrate non-installation surface outside the recess 6 a of the base 6. By forming the air blowing groove 8a, the flow of air flowing through the air blowing grooves 8, 8a becomes smooth, and an even higher heat dissipation effect is obtained. In the present embodiment, the air blowing grooves 8 and 8a are formed in a curved shape, and as a whole, form a spiral shape that swirls around the ventilation hole 7 in one rotation direction (clockwise rotation direction in FIGS. 1 and 2). . The trajectory drawn by the air blowing groove 8 is not particularly defined, but if it is bent too complexly, the flow resistance of the cooling air increases, the flow velocity decreases, and the cooling performance decreases. On the other hand, if the trajectory drawn by the air blowing groove 8 (8a) is too simple like a straight line, the contact area of the air flowing through the air blowing groove 8 (8a) with the LED substrate 5 becomes small, and the air blowing groove 8 (8a). The amount of heat exchange between the cooling air flowing through the LED board 5 and the base 6 is reduced, and the cooling effect of the LED board 5 and the base 6 is reduced.

ここで、各送風溝８の面積の総和は、ＬＥＤ基板５の面積に対して２０〜４０％に設定されている。各送風溝８の断面形状は特に限定されず、四角や半円であっても良い。又、各挿通溝８の幅や深さ、本数については、ブロア４の送風能力によって定めれば良く、本実施の形態では、ブロア４として吐出能力が１（リットル／分）のものを使用し、ベース６の基板設置面に、断面形状が幅２ｍｍ、深さ１ｍｍの断面半円の送風溝８を１０条形成した。尚、送風溝８の加工方法としては切削加工を用いても良いが、ベース６をダイキャストによって成形する場合には、その基板設置面に窪み６ａと共に送風溝８をダイキャストと同時に一体成形する方法を採用することが望ましい。 Here, the total area of the air blowing grooves 8 is set to 20 to 40% with respect to the area of the LED substrate 5. The cross-sectional shape of each blowing groove 8 is not particularly limited, and may be a square or a semicircle. Further, the width, depth, and number of each insertion groove 8 may be determined according to the blowing capacity of the blower 4. In this embodiment, the blower 4 having a discharge capacity of 1 (liter / minute) is used. On the substrate mounting surface of the base 6, ten air-sending grooves 8 having a cross-sectional shape of a width of 2 mm and a depth of 1 mm and a semicircular cross-section were formed. In addition, although the cutting process may be used as a processing method of the air blowing groove 8, when the base 6 is formed by die casting, the air blowing groove 8 is integrally formed at the same time as the die casting on the substrate installation surface together with the recess 6a. It is desirable to adopt a method.

前記ブロア４の駆動方式としては、圧電素子を用いる方式、電磁誘導方式等、種々の方式が考えられるが、本実施の形態では、ブロア４として小型で高い駆動圧力が得られる圧電素子を用いるものを使用した。このブロア４の上面（ＬＥＤ基板５への接触面）の中央部にはパイプ状の吐出ノズル４ａが突出しており、ブロア４は、図３に示すように吐出ノズル４アをベース６の通風孔７に下方から嵌め込み、その上面をベース６の下面に密着させた状態で組み付けられる。尚、筐体２内やブロア４の内部への塵埃等の微粒子の侵入を防ぐため、エアフィルタを適宜付加することが望ましい。 Various methods such as a method using a piezoelectric element and an electromagnetic induction method can be considered as a method for driving the blower 4. In the present embodiment, a piezoelectric element that is small and can obtain a high driving pressure is used as the blower 4. It was used. A pipe-like discharge nozzle 4a protrudes from the center of the upper surface of the blower 4 (the contact surface with the LED substrate 5). The blower 4 is connected to the discharge nozzle 4a as shown in FIG. 7 is fitted from below, and its upper surface is attached to the lower surface of the base 6 and assembled. In order to prevent fine particles such as dust from entering the housing 2 or the blower 4, it is desirable to add an air filter as appropriate.

又、図３に示すように、ＬＥＤ基板５は、ベース６の基板設置面に形成された窪み６ａに嵌め込まれることによってベース６上に載置固定される。ここで、ＬＥＤ基板５とベース６との接合には熱伝導性の高い接着剤やグリス等が使用されるが、本実施の形態では、ネジ止めによってＬＥＤ基板５とベース６とを接合した。又、ベース６とブロア４との固定には接着剤や両面テープ等が使用されるが、本実施の形態では耐熱性の高いシリコーン系接着剤を使用した。 As shown in FIG. 3, the LED substrate 5 is placed and fixed on the base 6 by being fitted into a recess 6 a formed on the substrate installation surface of the base 6. Here, an adhesive, grease, or the like with high thermal conductivity is used for joining the LED substrate 5 and the base 6, but in this embodiment, the LED substrate 5 and the base 6 are joined by screwing. Further, an adhesive, a double-sided tape, or the like is used for fixing the base 6 and the blower 4, but in this embodiment, a silicone adhesive having a high heat resistance is used.

以上のように構成された照明装置１において、発光部３のＬＥＤとブロア４に通電がなされると、ＬＥＤが発光して照明光がＬＥＤ基板５の発光面から出射し、この照明光によって周囲が照明されるが、ＬＥＤは発光によって発熱する。そして、この熱は、ＬＥＤ基板５から熱伝導率の高いベース６へと伝導し、ベース６の外表面から放熱されるとともに、筐体２の外表面からも放熱される。 In the illuminating device 1 configured as described above, when the LED of the light emitting unit 3 and the blower 4 are energized, the LED emits light, and the illumination light is emitted from the light emitting surface of the LED substrate 5. Is illuminated, but the LED generates heat by light emission. This heat is conducted from the LED substrate 5 to the base 6 having high thermal conductivity, and is radiated from the outer surface of the base 6 and is also radiated from the outer surface of the housing 2.

而して、ＬＥＤの発光と同時にブロア４がベース６の裏側で駆動され、図３に矢印にて示すように、ブロア４の吐出ノズル４ａからは冷却風がベース６の中心部に形成された通風孔７へと吐出される。このようにベース６の通風孔７へと吐出される冷却風は、通風孔７からベース６に形成された複数の送風溝８を通って発光部３のＬＥＤ基板５とベース６の間を図３に矢印にて示すように径方向外方へ向かって流れ、その過程でＬＥＤ基板５とベース６を強制空冷するため、発光部３が効率良く冷却されて照明装置１の明るさと寿命が高められる。このように、本実施の形態では、コンパクトで実用的な筐体放熱構造をそのまま活かしたブロア４による強制空冷方式が採用されているため、筐体２の側面や内部にヒートシンクを付加する必要がなく、筐体２の容積を小さく抑えて照明装置１の小型化と軽量化を図ることができる。 Thus, the blower 4 is driven on the back side of the base 6 simultaneously with the light emission of the LED, and cooling air is formed in the center of the base 6 from the discharge nozzle 4a of the blower 4 as indicated by the arrow in FIG. It is discharged to the ventilation hole 7. Thus, the cooling air discharged to the ventilation hole 7 of the base 6 passes through the plurality of ventilation grooves 8 formed in the base 6 from the ventilation hole 7 and passes between the LED substrate 5 and the base 6 of the light emitting unit 3. 3, the LED substrate 5 and the base 6 are forcibly air-cooled in the radial direction as indicated by arrows, so that the light emitting unit 3 is efficiently cooled and the brightness and life of the lighting device 1 are increased. It is done. As described above, in the present embodiment, the forced air cooling method using the blower 4 that utilizes the compact and practical case heat dissipation structure as it is is employed, so it is necessary to add a heat sink to the side surface or inside of the case 2. In addition, the volume of the housing 2 can be kept small, and the lighting device 1 can be reduced in size and weight.

又、本実施の形態では、ブロア４からの冷却風はベース７の通風孔７から放射状の送風溝８に沿ってＬＥＤ基板５とベース６の間を均一に流れてこれらのＬＥＤ基板５とベース６を全体的に均一に冷却するため、発光部３が効率良く冷却されて該発光部３の明るさと寿命が高められる。特に、本実施の形態では、各送風溝８を曲線状とて全体として螺旋状に旋回する形状としたため、該送風溝８の長さが長くなって冷却風が流れる時間も長くなり、冷却風量が増えるとともに、冷却風が旋回流となってＬＥＤ基板５とベース６の間を流れるため、この冷却風によってＬＥＤ基板５とベース６が一層効率良く冷却される。 In the present embodiment, the cooling air from the blower 4 flows uniformly between the LED board 5 and the base 6 along the radial air blowing grooves 8 from the ventilation holes 7 of the base 7, and these LED board 5 and the base. 6 is uniformly cooled as a whole, the light emitting unit 3 is efficiently cooled, and the brightness and life of the light emitting unit 3 are increased. In particular, in the present embodiment, since each of the air blowing grooves 8 has a curved shape and turns spirally as a whole, the length of the air blowing grooves 8 becomes longer and the time for cooling air to flow becomes longer. Since the cooling air flows as a swirl flow between the LED substrate 5 and the base 6, the LED substrate 5 and the base 6 are cooled more efficiently by this cooling air.

更に、本実施の形態では、各送風溝８の面積の総和をＬＥＤ基板５の面積に対して２０〜４０％に設定したため、発光部３の冷却に必要十分な冷却風の流量を確保しつつ、ＬＥＤ基板５からベース６への熱伝導を確保して発光部３を効率良く冷却することができる。因みに、各送風溝８の面積の総和がＬＥＤ基板５の面積に対して２０％未満である場合には、送風溝８を流れる冷却風の流量が不足するため、強制空冷による発光部３の冷却効果が低減する。又、逆に各送風溝８の面積の総和がＬＥＤ基板５の面積に対して４０％を超えると、ＬＥＤ基板５のベース６への接触面積が不足するためにＬＥＤ基板５からベース６への熱伝導量が不足し、発光部３の冷却効果が低減する。 Furthermore, in this Embodiment, since the sum total of the area of each ventilation groove | channel 8 was set to 20 to 40% with respect to the area of LED board 5, securing the flow volume of the cooling air required and sufficient for cooling of the light emission part 3 is ensured. Thus, heat conduction from the LED substrate 5 to the base 6 can be ensured, and the light emitting unit 3 can be efficiently cooled. Incidentally, when the total area of the air blowing grooves 8 is less than 20% with respect to the area of the LED substrate 5, the flow rate of the cooling air flowing through the air blowing grooves 8 is insufficient, so that the light emitting unit 3 is cooled by forced air cooling. The effect is reduced. Conversely, if the total area of the air blowing grooves 8 exceeds 40% of the area of the LED board 5, the contact area of the LED board 5 to the base 6 is insufficient, so that the LED board 5 to the base 6 The amount of heat conduction is insufficient, and the cooling effect of the light emitting unit 3 is reduced.

又、本実施の形態では、ブロア４として圧電素子によって駆動されるものを使用するため、軸流ファンとは違って高い駆動圧力が得られ、エアフィルタの付加によってもブロア４の吸入圧力や送風性能の低下を招くことがなく、ブロア４の消費電力を低く抑えることができる。 Further, in the present embodiment, since the blower 4 driven by a piezoelectric element is used, a high driving pressure is obtained unlike an axial fan, and the suction pressure and air flow of the blower 4 can also be obtained by adding an air filter. The power consumption of the blower 4 can be kept low without causing performance degradation.

次に、本発明による上記効果を検証するために行った実験について図４及び図５を参照しながら説明する。尚、図４（ａ）は本発明に係る冷却構造を示すベースの平面図、図４（ｂ）は比較例１に係る冷却構造を示すベースの平面図、図５は本発明と比較例１，２に係る冷却構造による冷却効果を示す図である。 Next, an experiment conducted for verifying the above-described effect according to the present invention will be described with reference to FIGS. 4A is a plan view of the base showing the cooling structure according to the present invention, FIG. 4B is a plan view of the base showing the cooling structure according to Comparative Example 1, and FIG. 5 is the present invention and Comparative Example 1. 2 is a diagram showing a cooling effect by the cooling structure according to FIGS.

実験は図１に示す照明装置１を用いて図４（ａ）に示す本発明に係る冷却構造、図４（ｂ）に示す比較例１に係る冷却構造（ベース６に通風孔７から放射状（十字状）に延びる４本の送風溝８を形成したもの）、図示しない比較例３に係る冷却構造（ベース６に送風溝８を全く設けないもの）について発光面中央（図１のａ点）とＬＥＤ基板端（図１のｂ点）及びベース端（図１のｃ点）の温度をそれぞれ測定することによって行われた。尚、図１に示す照明装置１の外径はφ６０ｍｍ、長さは１００ｍｍ程度であり、ＬＥＤ基板５としては一辺が３０ｍｍ程度のセラミック（アルミナ）基板が用いられ、このＬＥＤ基板５上に約１００個の青色ＬＥＤと黄色蛍光体を実装したマルチチップタイプの発光部３が用いられ、ＬＥＤへの投入電力は約５．５Ｗに統一した。 The experiment was conducted using the illumination device 1 shown in FIG. 1 and the cooling structure according to the present invention shown in FIG. 4A, the cooling structure according to Comparative Example 1 shown in FIG. (In the form of four crosses) extending in the shape of a cross), the center of the light emitting surface (point a in FIG. 1) of a cooling structure according to Comparative Example 3 (not shown) where the base 6 is not provided with any ventilation grooves 8 And LED substrate end (point b in FIG. 1) and base end (point c in FIG. 1) were measured, respectively. 1 has an outer diameter of about 60 mm and a length of about 100 mm. As the LED substrate 5, a ceramic (alumina) substrate having a side of about 30 mm is used. A multi-chip type light emitting unit 3 mounted with a single blue LED and a yellow phosphor was used, and the power input to the LED was unified to about 5.5 W.

本発明と比較例１及び比較例２に係る各冷却構造を備えた照明装置１に対して測定された各点（中央面位置、基板端及びベース端）での温度を図５に示す。尚、図５の縦軸のΔＴは周囲温度からの温度上昇値を示す。 FIG. 5 shows the temperature at each point (center plane position, substrate end and base end) measured with respect to the lighting device 1 having each cooling structure according to the present invention and Comparative Examples 1 and 2. Note that ΔT on the vertical axis in FIG. 5 indicates a temperature rise value from the ambient temperature.

図５に示す温度測定結果より、本発明では比較例２に対してＬＥＤ基板中央部で約６℃、基板端で約４℃の温度低減効果が得られることが分かった。これは、ブロア４からの冷却風がベース６に形成された送風溝８に沿って流れることによる熱交換の結果である。又、積分球での全光束測定結果から、６℃程度の温度低減によって明るさが５％程度向上することが確認された。 From the temperature measurement results shown in FIG. 5, it was found that the temperature reduction effect of about 6 ° C. at the center of the LED substrate and about 4 ° C. at the substrate edge can be obtained in the present invention. This is a result of heat exchange caused by the cooling air from the blower 4 flowing along the air blowing grooves 8 formed in the base 6. Also, from the result of total luminous flux measurement using an integrating sphere, it was confirmed that the brightness was improved by about 5% by reducing the temperature by about 6 ° C.

一方、比較例１は比較例２に対して発光面中央において約２℃の温度低減効果が得られたものの、基板端では逆に約２℃の温度上昇が見られた。これは、比較例１は本発明に対して送風溝８が占める面積が小さく、ブロア４からの冷却風にＬＥＤ基板５とベース６から十分熱が伝えられなかったためであると考えられる。 On the other hand, in Comparative Example 1, a temperature reduction effect of about 2 ° C. was obtained at the center of the light emitting surface as compared with Comparative Example 2, but a temperature increase of about 2 ° C. was observed at the substrate edge. This is probably because Comparative Example 1 has a smaller area occupied by the air blowing groove 8 than the present invention, and the heat from the LED substrate 5 and the base 6 was not sufficiently transferred to the cooling air from the blower 4.

尚、以上の実施の形態では、送風溝をベース側に形成したが、送風溝をＬＥＤ基板側に設けても良く、或いはベース側とＬＥＤ基板側の双方に挿通溝を形成しても良い。 In the above embodiment, the air blowing groove is formed on the base side. However, the air blowing groove may be provided on the LED substrate side, or insertion grooves may be formed on both the base side and the LED substrate side.

１照明装置
２筐体
２ａ筐体の口金部
３発光部
４ブロア
４ａブロアの吐出ノズル
５ＬＥＤ基板
６ベース
６ａベースの窪み
７通風孔
８，８ａ送風溝
DESCRIPTION OF SYMBOLS 1 Illuminating device 2 Case 2a Case base part 3 Light emitting part 4 Blower 4a Blower discharge nozzle 5 LED substrate 6 Base 6a Base depression 7 Ventilation hole 8, 8a

Claims

光源であるＬＥＤが実装されたＬＥＤ基板と該ＬＥＤ基板を載置するベースとから成る発光部と、該発光部の裏側から送風することによって発光部を強制空冷するブロアを筐体内に備えた照明装置の冷却構造であって、
前記ベースの中心部に通風孔を貫設し、該ベースの基板設置面と前記ＬＥＤ基板のベースへの設置面の少なくとも一方に複数の送風溝を形成したことを特徴とする照明装置の冷却構造。 A light emitting unit comprising an LED substrate on which an LED as a light source is mounted and a base on which the LED substrate is placed, and a blower that forcibly air-cools the light emitting unit by blowing air from the back side of the light emitting unit. A cooling structure of the device,
A cooling structure for an illuminating device, wherein a ventilation hole is provided in a central portion of the base, and a plurality of air blowing grooves are formed on at least one of a base mounting surface of the base and a base mounting surface of the LED substrate. .

前記送風溝を、前記通風孔を中心として放射状に形成したことを特徴とする請求項１記載の照明装置の冷却構造。 The cooling structure for a lighting device according to claim 1, wherein the air blowing groove is formed radially with the ventilation hole as a center.

前記各送風溝の面積の総和を前記ＬＥＤ基板の面積に対して２０〜４０％に設定したことを特徴とする請求項１又は２記載の照明装置の冷却構造。 The cooling structure of the illumination device according to claim 1 or 2, wherein the total area of the air blowing grooves is set to 20 to 40% with respect to the area of the LED substrate.

前記ブロアとして圧電素子で駆動されるものを使用することを特徴とする請求項１〜３の何れかに記載の照明装置の冷却構造。 The cooling structure for an illuminating device according to any one of claims 1 to 3, wherein the blower is driven by a piezoelectric element.

前記各総風溝と同一直線上となる形状の送風溝を前記ベースの基板設置面から外側に位置する基板非設置面に向かって形成したことを特徴とする請求項１〜４の何れかに記載の照明装置の冷却構造。
The air blowing groove having a shape that is collinear with each of the total air grooves is formed from the substrate installation surface of the base toward the substrate non-installation surface located outside. The cooling structure of the illuminating device described.