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EP 3 671 024 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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05.01.2022 Bulletin 2022/01 |
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Date of filing: 21.12.2018 |
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International Patent Classification (IPC):
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Cooperative Patent Classification (CPC): |
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F21S 45/47 |
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HEAT TRANSFER SYSTEM FOR A LIGHTING MODULE OF A MOTOR VEHICLE
WÄRMEÜBERTRAGUNGSSYSTEM FÜR EIN BELEUCHTUNGSMODUL EINES KRAFTFAHRZEUGS
SYSTÈME DE TRANSFERT DE CHALEUR POUR UN MODULE D'ÉCLAIRAGE D'UN VÉHICULE À MOTEUR
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Designated Contracting States: |
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AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL
NO PL PT RO RS SE SI SK SM TR |
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Date of publication of application: |
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24.06.2020 Bulletin 2020/26 |
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Proprietor: VALEO ILUMINACION, S.A. |
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23600 Martos (ES) |
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Inventors: |
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- GOMEZ, Carlos
23600 MARTOS (ES)
- BUENO, Macarena
23600 MARTOS (ES)
- PARRAS, Juan-Carlos
23600 MARTOS (ES)
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Representative: Valeo Visibility |
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Service Propriété Industrielle
c/o Valeo Vision
34, rue Saint André 93012 Bobigny 93012 Bobigny (FR) |
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References cited: :
EP-A1- 3 168 526 US-A1- 2011 068 687
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EP-A2- 2 762 771 US-A1- 2016 084 460
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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TECHNICAL FIELD
[0001] The present invention relates to a heat transfer system for a lighting module of
a motor vehicle.
[0002] The invention also relates to a motor vehicle lighting device comprising such a lighting
module.
STATE OF THE ART
[0003] For the illumination of path of automotive vehicles, the use of lighting modules
comprising a light source using LEDs (light-emitting diodes) is known.
[0004] Such system lighting modules using light source comprising LEDs makes it possible
to provide proper lighting in front of the vehicle. They are therefore used to perform
various functions such as for example road lighting function to illuminate the path
and also avoid dazzling other motorists, or for signaling functions.
[0005] During the operation, such a lighting module can become very hot due to the use of
LEDs and the heat generated by the motor compartment. Excessive heating leads to malfunction
of the LED or even destruction of the system and/ or the control circuit. It is therefore
needed to cool the lighting module, in order to keep the LED under their junction
temperature, above which their performance is decreasing. In that end, the use of
heatsinks with airfoils or fins is known. However, such cooling means are not always
sufficiently efficient in maintaining the lighting module below a damaging temperature.
To improve the efficiency of such heat sink many solutions have been tried such as
active cooling with fans blowing air toward the fins of the heat sink or anodization
or cataphoresis. Such systems have been explained in Patent such as
KR 20160000832 U and
US 2008175008 A1. This prior art discloses surface treated led lamp by arc plasma anodizing and also
improvement of heatsink radiation by vacuum sputtering, vaporization and anodizing
respectively. Both the prior art document, talk about anodizing of all the fins of
the heat sink. Such methods are complicated in nature and therefore costly.
EP 2 762 771 A2 and
US 2011/068687 A1 disclose further lighting modules of the prior art.
SUMMARY OF THE INVENTION
[0006] An object of the present invention is to solve at least partially the disadvantages
described above of known lighting module. In particular, it is the object of the present
invention to provide a lighting module device with an improved and compact heat exchange
system which is easy to implement and affordable.
[0007] According to the present invention there is provided a lighting module for an automotive
vehicle comprising a light source for producing a light beam in front of the vehicle.
The lighting module further comprises a heat exchange system for transferring heat
away from the light source, the heat exchange system. The heat exchange system has
a heat sink plate and plurality of heat transfer airfoils thermally connected to the
heat sink plate.
[0008] The heat transfer airfoils of the heat exchange system according to the present invention
have a plurality of non-anodized heat transfer airfoils and a pair of anodized heat
transfer airfoils. The pair of anodized heat transfer airfoils are at peripheral portion
encompassing the plurality of non-anodized airfoils of the heat exchange system. Indeed,
such an arrangement wherein only peripheral airfoils are anodized has shown to decrease
significantly the junction temperature compared to a heat exchange system without
any anodized airfoils and is quite as efficient than a full set of anodized airfoils,
for a much better production cost. According to another embodiment of the present
invention, the heat sink plate of the heat transfer system is provided with an enveloping
airfoil over the plurality of non-anodized heat transfer airfoils and the pair of
anodized heat transfer airfoils. The enveloping airfoil of the embodiment of the present
invention is connected on the anodized heat transfer airfoil at peripheral portion
of the heat exchange system. The enveloping airfoil is also anodized to improve the
heat transfer. This arrangement increases further the heat transfer efficiency, while
still limiting the cost compared to a full set of anodized airfoils.
[0009] According to another embodiment of the present invention, one of the heat transfer
airfoil is provided at peripheral portion is orientated towards the visible side of
the lighting module.
[0010] According to the embodiment of the present invention, the heat transfer airfoil oriented
towards the visible side of the lighting module is anodized to improve the heat transfer.
[0011] According to the embodiment of the invention, the anodized heat transfer airfoil
are provided with a thin plastic coating to improve the heat transfer and the aesthetic
of the lighting module, when considering the heat transfer airfoil oriented towards
the visible side of the lighting module.
[0012] According to the embodiment of the present invention, the thin plastic coating provided
on the heat transfer airfoil is lower than 100 microns.
BRIEF DESCRIPTION OF THE INVENTION
[0013] To complete the description and to provide a better understanding of the invention,
a set of drawings is provided. Said drawings form an integral part of the description
and illustrate an embodiment of the invention, which should not be construed as restricting
the scope of the invention, but only as an example of how the invention can be carried
out. The drawings comprise the following characteristics.
Figure 1 shows a perspective view of a heat exchange system of a lighting module,
according to the embodiment of present invention. The figure shows the arrangement
of the plurality of heat transfer airfoils arranged on a heat sink plate.
Figure 2 shows a perspective view of a heat exchange system of lighting module, according
to another embodiment of the present invention. The figure shows an enveloping airfoil
arranged on the plurality of airfoils of the heat sink.
Figure 3 is another embodiment of the lighting module of the present invention, wherein
the anodized fin lies in a visible area of the lighting module.
Figure 4 shows the lighting module of the Figure 3. The figure shows airfoil of the
heat sink plate coated with a thin plastic coating.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Hereinafter, embodiments of the present invention will be described with reference
to the accompanying drawings.
[0015] Figure 1 shows a perspective view of a heat exchange system 100 of lighting device
having a light source 10 such as LED for producing a light beam, according to an embodiment
of the present invention.
[0016] According to an embodiment of the present subject matter, the heat exchange system
(100) shown in Figure 1 comprises a heat sink plate (11) provided with a plurality
of heat transfer airfoils for transferring heat away from the heat sink plate 11.
In lighting module of present subject matter, to avoid component failure due to heat
generation, the lighting module is provided with such heat exchange system for reducing
heat generated inside the module. Such heat sink plate are provided with plurality
of airfoils to increase heat convection dissipation. To further to improve the heat
dissipation by radiation, surface treatment such as anodization or cataphoresis is
done to increasing radiation emissivity of the airfoils. But the only surface where
this emissivity improvement is useful is the outer surface because of the emission
of inner airfoils is compensated by the emission of its in front airfoils.
[0017] Accordingly, the pluralities of heat transfer airfoils of heat exchange system 100
of the present invention are made of two types. The heat exchange system 100 is provided
with a plurality of non-anodized heat transfer airfoils 14 and a pair of anodized
heat transfer airfoils 12. The pair of anodized heat transfer airfoils 12 is placed
at peripheral portion of the heat sink plate 11. The pair anodized heat transfer airfoils
12 are arranged such that they encompass the plurality of non-anodized heat transfer
airfoils 14 of the heat exchange system 100. As per the embodiment, it signifies that
only the first and the last heat transfer airfoils or the peripheral airfoils are
anodized and the remaining heat transfer airfoils are not anodized. The plurality
of non-anodized heat transfer airfoils 14 and the pair of anodized heat transfer airfoils
12 are thermally connected to the heat sink plate 11 and radiate outwards.
[0018] Comparative test showed that the design according to the invention allowed a decrease
of 14.5 °C of the junction temperature of the LED compared to a heat sink plate provided
with a full set of non anodized airfoils whereas a full set of anodized airfoils allowed
to achieve a decrease of 18°C of the junction temperature of the LED.
[0019] Figure 2 shows another embodiment of the present invention. According to this embodiment
of the present invention, the heat transfer system 100 comprises a heat sink plate
11, a plurality or non-anodized heat transfer airfoil 14 and a pair of anodized heat
transfer airfoils 12. Additionally, the heat transfer system 100 comprises an enveloping
airfoil 16. The enveloping airfoil 16 is connected on the pair of anodized heat transfer
airfoil 12 provided at peripheral portion of the heat exchange system (100). The embodiment
provides emissivity improvement on the outer side of this surface. The enveloping
airfoil 16 of the present invention is also anodized to attain the objectives according
to the scope of invention.
[0020] According to yet another embodiment of present invention as shown if Figure 3, at
least one anodized heat transfer airfoil 12 at peripheral portion is orientated towards
the visible side of the lighting module. The Figure shows a light source 10 such as
a LED assembled inside the housing 20 of a motor vehicle lighting device. The figure
also shows the heat sink plate 11 arranged in relation to the light source 10. The
provision of the anodized airfoil in the visible area of the lighting device provides
higher heat dissipation due to relatively lower temperature near the outer side of
lighting device.
[0021] Figure 4 shows another embodiment of the present invention where the at least one
anodized heat transfer airfoil 12 , for instance here the one provided at peripheral
portion, is coated with a thin plastic coating 12a. The size of the thin plastic coating
12a provided on the heat transfer airfoil 12 is lower than 100 microns. The thin plastic
coating 12a is provided with additional aesthetic design or feature to improve the
design of the lighting module. The addition of the thin plastic coating 12a further
improves the emissivity of the heat sink and ensures better heat transfer in the lighting
module.
1. A lighting module for a automotive vehicle comprising:
a light source (10) for producing a light beam; and
a heat exchange system (100) for transferring heat away from the light source (10),
the heat exchange system (100) comprising:
a heat sink plate (11);
characterized in that the heat exchange system (100) further comprises a plurality of non-anodized heat
transfer airfoils (14) and a pair of anodized heat transfer airfoils (12), wherein
the pair of anodized heat transfer airfoils (12) are at peripheral portion encompassing
the plurality of non-anodized airfoils (14) of the heat exchange system (100).
2. The lighting module as claimed in claim 1, wherein the plurality of non-anodized heat
transfer airfoils (14) and the pair of anodized airfoils (12) are thermally connected
to the heat sink plate (11).
3. The lighting module as claimed in claim 1 or 2, wherein at least one anodized heat
transfer airfoil (12) at peripheral portion is orientated towards the visible side
of the lighting module.
4. The lighting module as claimed in claim 1 to 3, wherein the heat sink plate (11) is
provided with an enveloping airfoil (16) over the plurality of non-anodized heat transfer
airfoils (14) and the pair of anodized heat transfer airfoils (12).
5. The lighting module as claimed in any of claim 1 to 4, wherein at least one anodized
heat transfer airfoil (12) is provided with a thin plastic coating (12a).
6. The lighting module as claimed in claim 5, wherein the thin plastic coating (12a)
provided on the heat transfer airfoil (12) is lower than 100 microns.
7. The lighting module as claimed in any of claims 4 to 6, wherein the enveloping airfoil
(16) is connected on the two anodized heat transfer airfoil (12) at peripheral portion
of the heat exchange system (100).
8. The lighting module as claimed in any of claim 4 to 7, wherein the enveloping airfoil
(16) is also anodized.
9. The lighting module as claimed in any of preceding claims, wherein the light source
(10) is a LED disposed on a LED circuit board.
10. The lighting module as claimed in any of the preceding claims, wherein the plurality
of non-anodized heat transfer airfoils (14) and the pair of anodized heat transfer
airfoils (12) are made of aluminium.
11. Motor vehicle lighting device comprising a lighting module according to any of the
preceding claims.
1. Beleuchtungsmodul für ein Kraftfahrzeug, Folgendes umfassend:
eine Lichtquelle (10) zum Erzeugen eines Lichtstrahls und
ein Wärmetauschsystem (100) zum Übertragen von Wärme weg von der Lichtquelle (10),
wobei das Wärmetauschsystem (100) Folgendes umfasst ein Kühlblech (11),
dadurch gekennzeichnet, dass das Wärmetauschsystem (100) ferner mehrere nicht anodisierte Wärmeübertragungsluftleitbleche
(14) und ein Paar anodisierter Wärmeübertragungsluftleitbleche (12) umfasst, wobei
sich das Paar anodisierter Wärmeübertragungsluftleitbleche (12) an einem Umfangsabschnitt
befindet, der die mehreren nicht anodisierten Luftleitbleche (14) des Wärmetauschsystems
(100) umschließt.
2. Beleuchtungsmodul nach Anspruch 1, wobei die mehreren nicht anodisierten Wärmeübertragungsluftleitbleche
(14) und das Paar anodisierter Wärmeübertragungsluftleitbleche (12) thermisch mit
dem Kühlblech (11) verbunden sind.
3. Beleuchtungsmodul nach Anspruch 1 oder 2, wobei mindestens ein anodisiertes Wärmeübertragungsluftleitblech
(12) am Umfangsabschnitt hin zur sichtbaren Seite des Beleuchtungsmoduls ausgerichtet
ist.
4. Beleuchtungsmodul nach Anspruch 1 bis 3, wobei das Kühlblech (11) mit einem umhüllenden
Luftleitblech (16) über den mehreren nicht anodisierten Wärmeübertragungsluftleitblechen
(14) und dem Paar anodisierter Wärmeübertragungsluftleitbleche (12) versehen ist.
5. Beleuchtungsmodul nach einem der Ansprüche 1 bis 4, wobei mindestens ein anodisiertes
Wärmeübertragungsluftleitblech (12) mit einem dünnen Kunststoffüberzug (12a) versehen
ist.
6. Beleuchtungsmodul nach Anspruch 5, wobei der dünne Kunststoffüberzug (12a), mit dem
das Wärmeübertragungsluftleitblech (12) versehen ist, dünner als 100 Mikrometer ist.
7. Beleuchtungsmodul nach einem der Ansprüche 4 bis 6, wobei das umhüllende Luftleitblech
(16) an einem Umfangsabschnitt des Wärmetauschsystems (100) mit den zwei anodisierten
Wärmeübertragungsluftleitblechen (12) verbunden ist.
8. Beleuchtungsmodul nach einem der Ansprüche 4 bis 7, wobei das umhüllende Luftleitblech
(16) ebenfalls anodisiert ist.
9. Beleuchtungsmodul nach einem der vorhergehenden Ansprüche, wobei die Lichtquelle (10)
eine LED ist, die auf einer LED-Leiterplatte angeordnet ist.
10. Beleuchtungsmodul nach einem der vorhergehenden Ansprüche, wobei die mehreren nicht
anodisierten Wärmeübertragungsluftleitbleche (14) und das Paar anodisierter Wärmeübertragungsluftleitbleche
(12) aus Aluminium bestehen.
11. Kraftfahrzeug-Beleuchtungsvorrichtung, umfassend ein Beleuchtungsmodul nach einem
der vorhergehenden Ansprüche.
1. Module d'éclairage pour un véhicule automobile comprenant :
une source de lumière (10) pour produire un faisceau lumineux ; et
un système d'échange de chaleur (100) pour transférer la chaleur à l'écart de la source
de lumière (10), le système d'échange de chaleur (100) comprenant une plaque de dissipation
thermique (11) ;
caractérisé en ce que le système d'échange de chaleur (100) comprend en outre une pluralité d'ailettes
de transfert de chaleur non anodisées (14) et une paire d'ailettes de transfert de
chaleur anodisées (12), dans lequel la paire d'ailettes de transfert de chaleur anodisées
(12) se trouve au niveau de la partie périphérique englobant la pluralité d'ailettes
non anodisées (14) du système d'échange de chaleur (100).
2. Module d'éclairage selon la revendication 1, dans lequel la pluralité d'ailettes de
transfert de chaleur non anodisées (14) et la paire d'ailettes anodisées (12) sont
connectées thermiquement à la plaque de dissipation thermique (11).
3. Module d'éclairage selon la revendication 1 ou 2, dans lequel au moins une ailette
de transfert de chaleur anodisée (12) à la partie périphérique est orientée vers le
côté visible du module d'éclairage.
4. Module d'éclairage selon l'une des revendications 1 à 3, dans lequel la plaque de
dissipation thermique (11) est pourvue d'une ailette enveloppante (16) au-dessus de
la pluralité d'ailettes de transfert de chaleur non anodisées (14) et la paire d'ailettes
de transfert de chaleur anodisées (12).
5. Module d'éclairage selon l'une quelconque des revendications 1 à 4, dans lequel au
moins une ailette de transfert de chaleur anodisée (12) est pourvue d'un revêtement
plastique mince (12a).
6. Module d'éclairage selon la revendication 5, dans lequel le revêtement plastique mince
(12a) prévu sur l'ailette de transfert de chaleur (12) est inférieur à 100 microns.
7. Module d'éclairage selon l'une quelconque des revendications 4 à 6, dans lequel l'ailette
enveloppant (16) est relié aux deux ailettes de transfert de chaleur anodisés (12)
au niveau de la partie périphérique du système d'échange de chaleur (100).
8. Module d'éclairage selon l'une quelconque des revendications 4 à 7, dans lequel l'ailette
enveloppante (16) est également anodisée.
9. Module d'éclairage selon l'une quelconque des revendications précédentes, dans lequel
la source de lumière (10) est une LED disposée sur une carte de circuit LED.
10. Module d'éclairage selon l'une quelconque des revendications précédentes, dans lequel
la pluralité d'ailettes de transfert de chaleur non anodisées (14) et la paire d'ailettes
de transfert de chaleur anodisées (12) sont réalisées en aluminium.
11. Dispositif d'éclairage de véhicule automobile comprenant un module d'éclairage selon
l'une quelconque des revendications précédentes.
REFERENCES CITED IN THE DESCRIPTION
This list of references cited by the applicant is for the reader's convenience only.
It does not form part of the European patent document. Even though great care has
been taken in compiling the references, errors or omissions cannot be excluded and
the EPO disclaims all liability in this regard.
Patent documents cited in the description