U.S. patent application number 13/496808 was filed with the patent office on 2012-08-23 for cooling device for a heat source.
Invention is credited to Jamie Donaldson, Abdallah Haddad, Hans Kunstwadl, Song Lin.
Application Number | 20120211201 13/496808 |
Document ID | / |
Family ID | 41795477 |
Filed Date | 2012-08-23 |
United States Patent
Application |
20120211201 |
Kind Code |
A1 |
Kunstwadl; Hans ; et
al. |
August 23, 2012 |
COOLING DEVICE FOR A HEAT SOURCE
Abstract
A cooling element for a heat source, especially LED modules with
many components, includes a base body in thermal and mechanical
contact with a body of the heat source, at least one heat pipe
having an end section inserted into the base body in a form-fitting
and thermoconducting manner, and at least one cooling body having
cooling body lamellae on the other end section of the heat pipe.
The heat pipes extend over the entire length of the base body such
that a hot zone of the heat source lies on a contact surface of the
base body, the heat pipes extend parallel to each other and to the
contact surface of the heat source. The base body is fixed to the
body of the heat source, base body lamellae being provided on the
outer side of the base body, formed as a single component thereon
or connected thereto.
Inventors: |
Kunstwadl; Hans; (Markt
Schwaben, DE) ; Haddad; Abdallah; (Munchen, DE)
; Lin; Song; (Cheilaston, GB) ; Donaldson;
Jamie; (Badlington, GB) |
Family ID: |
41795477 |
Appl. No.: |
13/496808 |
Filed: |
September 9, 2010 |
PCT Filed: |
September 9, 2010 |
PCT NO: |
PCT/DE2010/075087 |
371 Date: |
May 3, 2012 |
Current U.S.
Class: |
165/104.21 |
Current CPC
Class: |
F21S 45/47 20180101;
H01L 23/427 20130101; F21V 29/713 20150115; F28D 15/0275 20130101;
F21S 2/005 20130101; F21V 29/745 20150115; F21V 29/76 20150115;
H01L 2924/0002 20130101; F21V 29/75 20150115; F21Y 2115/10
20160801; F21V 29/74 20150115; F21V 29/717 20150115; H01L 23/467
20130101; H01L 2924/0002 20130101; H01L 2924/00 20130101 |
Class at
Publication: |
165/104.21 |
International
Class: |
F28D 15/02 20060101
F28D015/02 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 17, 2009 |
DE |
202009012555.6 |
Apr 9, 2010 |
DE |
202010000549.3 |
Claims
1-17. (canceled)
18. A cooling element for a heat source, particularly for highly
equipped LED modules, comprising: one base body that is in thermal
and mechanical contact with a body of the heat source; at least one
heat pipe, whose end is received in a form-fitting and thermally
conducting manner in the base body; and at least one cooling
element with cooling body lamellae on the other end of the heat
pipe, wherein: the heat pipes run over an entire length of the base
body so that the heat source is in contact with a hot zone on a
contact surface of the base body, whereby the heat pipes run
parallel to each other spaced from another and parallel to a
contact surface of the heat source with the hot zone, and the base
body is fastened to the body of the heat source, lamellae which are
connected with the base body are provided on an exterior of the
base body and are integrally formed therewith, and the heat pipes
run in an angle increasing outward in an end direction of the
cooling element, whereby a positive angle of a warm side to a cold
side is present.
19. The cooling element according to claim 18, wherein at least two
heat pipes are provided that, outside of the base body, lead away
from each other in a pitchfork-like manner, and thereafter run
parallel to one another with a larger distance between them,
whereby the cooling body is formed by an outer sec of the heatpipes
having greater distance therebetween with cooling body lamellae
provided thereto.
20. The cooling element according to claim 18, wherein three
thermoconducting pipes are provided, whereby a straight central
heat pipe runs in the middle between two outer, pitchfork-shaped,
heat pipes that are bent outwardly in a three-pronged-fork-like
manner, whereby the cooling body is formed through a part thereof
with parallel section areas of the heat pipes having cooling body
lamellae.
21. The cooling element according to claim 18, wherein that the
heat pipes are received in holes along a whole length of the base
body or are set in a groove that is open to the contact surface
between the base body and the heat source, so that there is good
contact between the heat pipes and the contact surface of the heat
source.
22. The cooling element according to claim 18, wherein the base
body is a plate with exterior base body lamellae extending from the
contact surface.
23. The cooling element according to claim 22, wherein the plate of
the base body is thinner than a diameter of the heat pipe and is
arched around the heat pipe through grooves.
24. The cooling element according to claim 21, wherein the base
body with a base body section and base body sides at least
partially wraps around the heat source in a U-form, whereby the
base body sides provide support.
25. The cooling element according to claim 21, wherein the base
body lamellae run perpendicular or parallel to the base body.
26. The cooling element according to claim 24, wherein on the base
body sides axially aligned base body lamellae are provided in
addition to the lamellae extending upwards from a floor of the base
body, as side lamellae.
27. The Cooling element according to claim 26, wherein in the base
body floor section thread holes are provided to fasten to the heat
source that correspond with holes in the heat source, whereby
optionally additional fastening holes are provided in the base body
which mirror said threaded holes so that turning the entire cooling
element by 180 degrees to the heating source is possible.
28. The cooling element according to claim 18, wherein the cooling
body lamellae are rectangular, with arch-shaped and wing-shaped
sections, oval or cloud-like notches in an oval or cloud-like
fashion, round or other metal cuttings, in order to ensure a
minimal visible surface of the cooling body.
29. The cooling element according to claim 18, wherein the cooling
lamellae of the cooling body are press- or shrink-fit on the heat
pipes at a predetermined distance from one another, whereby spacers
are provided between the cooling lamellae.
30. The cooling element according to claim 29, wherein the spacers
are punched out from lamellae sheet tongues, bent away from a
lamella main level.
31. The cooling element according to claim wherein on a lower side
of the cooling body lamellae, at least one slit running from top to
bottom or leading inside is provided to accommodate vertical
support sheets.
32. The cooling element according to claim 18, wherein the cooling
element is configured above the base body, whereby the heat pipes
on the cooling element connected to the thermal conducting tubes
are bent upwards in a U-shape.
33. The cooling element according to claim 18, wherein openings for
the heat pipes of the cooling body cooling lamellae comprise a
step-like deep drawn area in their circumference, so that after
passing through the heat pipe, adhesives can collect in a groove
formed between the heat pipe and the cooling body lamella.
34. The cooling element according to claim 27, wherein the cooling
body lamellae are rectangular, with arch-shaped and wing-shaped
sections, oval or cloud-like notches in an oval or cloud-like
fashion, round or other metal cuttings, in order to ensure a
minimal visible surface of the cooling body.
35. The cooling element according to claim 19, wherein on a lower
side of the cooling body lamellae, at least one slit running from
top to bottom or leading inside is provided to accommodate vertical
support sheets.
36. The cooling element according to claim 20, wherein on a lower
side of the cooling body lamellae, at least one slit running from
top to bottom or leading inside is provided to accommodate vertical
support sheets.
37. The cooling element according to claim 21, wherein on a lower
side of the cooling body lamellae, at least one slit running from
top to bottom or leading inside is provided to accommodate vertical
support sheets.
Description
[0001] The invention concerns a cooling element for the cooling of
a heat source, for example an LED module in accordance with the
first part of claim 1, as they are used, for example, as LED lights
to illuminate interior spaces and in some outdoor areas (e.g.
tunnels, gardens, building illumination).
[0002] LEDs (light emitting diodes) are often used as light
sources. LEDs are electronic semi-conductor components. If
electricity flows through the diode in the direction of the outlet,
light is emitted. Light diodes possess an exponentially increasing
current-voltage-characteristic (I-V curve) which, among other
things, depends on temperature. The luminous flux is nearly
proportional to the operating current. The forward voltage adjusts
itself due to constant current through operation, possesses
tolerances and is temperature-dependant--it sinks with increasing
temperature as with all semiconductor diodes. High temperatures
(usually due to high currents) shorten the life span of LED's
dramatically.
[0003] Typically, multiple light emitting diodes together on one
carrier are arranged to one unit colloquially referred to as an
"LED" light, which is now also subsequently referred to as an LED.
The brightness of an LED grows with power consumption. At a
constant semiconductor temperature the increase is roughly
proportional. The level of efficiency drops with increasing
temperature, and it is for this reason that the light yield drops
at the limit of performance depending on the type of cooling. LED's
generally have bad thermal stability which is why they must be
cooled off for long-time use, so that their lifespan is not
dramatically shortened. Heavily populated LED modules, meaning
modules which are furnished with many light-emitting diodes, like,
for example, the Fortimo DLM Line by Philips, or XLM by Xicato, or
BOA by Bridgelux, and others, are particularly heat sensitive.
[0004] The heat produced by the operating current as thermal power
loss may not heat up the module above 65.degree. C. at the housing
measuring point defined in order to be able to ensure the
predetermined lumen output (luminous flux unit ->luminosity) and
the required lifespan (min. 50,000 operating hours).
[0005] In order to achieve this various precautions have already
been taken.
[0006] Attempts were made to cool using free convection on the
LED's extensive housing, or with these thermally connected
arrangements with cooling elements (passive cooling), i.e. using
diverse lamellae arrangements. Apart from the fact that a lot of
space is required for this these relatively heavy metal elements
form inefficient cooling elements, particularly in the assembly of
a larger number of LEDs in the module or lamp body (DE 10 2007 030
186 B1, DE 20 2008 906 325 U1).
[0007] Further, using actively moved elements for cooling (active
cooling) is known, for which, in connection with convection
elements, motor driven fans, or a oscillating membrane, are used,
see "Application guide, Philips Fortimo LED downlight module system
(DLM)". Page 18, Abb.: SynJet cooling System von Nuventix: Apart
from the fact that these elements also require additional energy to
function, they produce very disruptive noises (over 20 db), which
can lead to very high resonances, particularly with the
arrangements of many lights of this kind on suspended ceilings of
larger rooms, in addition vibrations and echo effects occur which
can build up to extremely distracting background noise, up to five
times amplification. In addition the side lamellae cooling elements
provided are not suited for, and also not intended, to enable the
necessary reduction in temperature. They only serve to spread the
heat. For this reason these lights could only be used to a limited
extent until now.
[0008] Finally, it is known to use arrangements with heat pipes for
heat dissipation. For example, cooling elements with heat pipes,
with which one end of the heat pipes is thermally connected with a
heat source, while their external sections are equipped with a
lamellae-equipped, or lamellae-like, cooling element, are known
from DE 10 2007 038 909 A1 and DE 10 2006 045 701 A1. Apart from
the fact that this concerns systems that are practically useful
only in outdoor applications in motor vehicles and not for lights
to be used indoors, therefore not for indoor applications, this
concerns cooling threads shaped directly on the pipe casing and
ineffective cooling elements, or a lamella package which is applied
on heat pipes with various contents and purposes. These cooling
elements are not suitable for cooling lights in building spaces.
Cooling elements in accordance with the category are known from EP
1903278 A1 and DE 20 2009008456U1, which are, however, not
satisfactorily manufacturable and/or sufficiently efficient and
space saving--particularly for application in lighting elements.
Therefore, the problem of the invention is to create a space-saving
cooling element, in accordance with the category, for effective,
silent cooling of lights with a high number of LEDs.
[0009] The problem is solved by a cooling element with the
characterizing features of claim 1. Advantageous embodiments may be
taken from the dependent claims.
[0010] The basic elements in a cooling element according to the
invention are: at least one, preferably two, three, or more heat
pipes which extend on a common level and for each of which one
(first) end section is embedded in one of the base bodies to be
connected to the heat source, while on the other (second) end
section a cooling body is attached consisting of multiple lamellae.
The heat pipes are arranged across the entire length of the base
body so that the heat source, or the LED module, lies on the base
area of the base body. In doing so, the heat pipes run parallel to
each other and to the metal contact surfaces, parallel to the heat
source with the hottest zone (hot spot). The lamellae are provided
integrally with these on the exterior of the base body.
Consequently, one end of the tubes runs very close along the hot
base of the LED module across its entire length, so that a very
good thermal conduction from the heat source to the heat pipes is
ensured. In addition, the lamellae are already being cooled in the
area of the base body and the heat source above the base body at
the same time, thereby, on the whole, significantly contributing to
the heat dissipation.
[0011] It is beneficial that the base body lamellae, which can be
designed differently, are arranged on the base body in a transverse
or longitudinal direction. For the primarily U-shaped base body,
surrounding the U-shaped metal housing of the rectangular-shaped
LED modules at least partially, offers, to also arrange the
lamellae in a U-shape in transverse axial succession. However, it
simpler if the cooling ribs or lamellae are arranged lengthwise or
axially for manufacture. Therefore the base body is, as a whole,
manufacturable as one piece using extrusion or extrusion
moulding.
[0012] It can be advantageous if two or three or more heat pipes
always running through one common level are used for one cooling
element. In this way three heat pipes can be used together, which,
for example, have a pipe diameter of 5 mm, whereby the arrangement
of the heat pipes is selected in such as way that their first end
section is embedded in a form-fitting, and thermally conductive
manner, in the base body in the corresponding opening and in the
corresponding axially parallel distance to one another, while they
are continued in various forms after their exit from the base body.
In this way, for example, a central
heat pipe is extends axially in a straight direction while both
side heat pipes extend on their separate ways, and the distance
between the heat pipes increases across a relatively short
distance, for better heat dissipation, after which they continue
even axially parallel in the cooling body so that, overall, a
forked arrangement of the heat pipes exists.
[0013] The cooling body, which consists primarily of many parallel,
distanced lamellae, stretches across the entire second end section
of the heat pipes. The lamellae are advantageously designed so that
through-holes for the passage of the heat pipes are shaped so that
the heat pipes, in press fit, or shrink fit, are firmly in tight,
thermally conducting, form-fitting contact with the lamellae,
whereby optimum thermally conducting contacts between the heat
pipes and the lamellae are ensured.
[0014] In order to simply maintain a constant distance between the
lamellae various spacers can be used. These, for example, can, in
each case, be simple spacer rings on both of the exterior heat
pipes. They have spacers rising vertically out of the lamellae,
which can be directly cut in, in a tongue-like manner, and
vertically bent out by the punching manufacturer.
[0015] With an embodiment with only two heat pipes they are
similarly shaped as the two external heat pipes of the
above-described embodiment with three heat pipes. The first end
sections of the heat pipes in the interior of the base body also
run parallel to each other, then after exiting the base body
diverging and upon entry into the cooling body again parallel to
one another so that the shape is roughly like a tuning fork. Here
it can be useful to select heat pipes with a somewhat thicker
diameter, i.e. with 6 mm, so that overall similar thermal and
strength conditions exist as in the embodiment with three pipes
with a diameter of 5 mm.
[0016] The heat pipes can, in a first embodiment, be embedded,
form-locking, in axial or longitudinal holes, in the base body base
section, along its entire length, whereby they have no physical
contact with the hot zone of the LED module. Through the good
conductivity of the base body, particularly the base section, in
which the heat pipes are embedded, the heat absorbed by the base
body through its close contact with the hot zone of the module to
be cooled off, can be easily transferred to the pipes and active
vaporization of the fluid medium found in the heat pipes under
absorption of the latent warmth, and with that the dissipation in
the following cool zone with condensation and release of the latent
warmth takes place.
[0017] Usually the heat pipes extend through the thermal absorption
plates. However, for some applications it is advantageous if the
heat pipes are each placed in a groove which is open to the contact
surface of the base body-base element. In doing so, the cross
section of the grooves can be designed essentially U-shaped for
maximum contact and form fit, with the same groove-base diameter as
those of the heat pipes and a groove height according to the
thickness of the heat pipes. As a result, full surface contact with
the LED module in the base body occurs concurrently with direct
contact between the heat pipes and the hot base surface of the LED
modules. Therefore a particularly good thermal contact is obtained
so that the evaporization of the medium of the heat pipes and with
it most efficient heat dissipation can occur.
[0018] According to the invention, the base body can have various
embodiments. It can be designed as a simple plate, upon or to
which, an LED module can be fastened, with good contacts,
accordingly. Then the plate comprises vertically extending lamellae
on its flat exterior accordingly, which can run lengthwise or
crosswise for the course of the heat pipes arranged therein.
[0019] However, the base body can also be designed so that it can,
at least, partially laterally encompass the heat source, or the LED
Module, in a U shape, therefore itself have a U-shape. Therefore,
the base body comprises a base body floor section wherein the heat
pipes extend partially in corresponding holes, or grooves, as well
as two sides vertically thereto. The distance between the base body
sides is to be designed so that their inner flanks have a good
contact area and therefore lie on the metal flanks of the LED
module so that they are thermally conductive. In order to establish
this contact the base body sides can also be attached on the side
using fasteners on the flanks of the LED module.
[0020] Further, the base body sidewalls along the flank of the LED
can run shorter or longer. So, for example, a base body side length
of only 0.5 to 15 mm, preferably 8 mm, is conceivable which only
serves as a fastening aid. The short base body side design form has
the significant advantage that more leeway remains for mounting a
light housing to be used, which then encroaches upon or is fastened
to the lower part of the LED module.
[0021] In a further embodiment the base body, or at least its base
body floor section, is relatively thin. The thickness of the base
body floor section is less than the diameter of the heat pipes. At
the same time grooves with an opening directed to the contact
surface for simple insertion of the heat pipes are provided, while
the thin material of the base body is guided around these grooves
in an arched shape. In addition, the lamellae provided on the front
side of the base body protrude vertically from the exterior of the
base body floor section so that optimal heat dissipation, with
economic material use, exists.
[0022] With long U-shaped encompassing base body side walls, and
axially extending lamellae, side lamellae can also be provided in
addition to the lamellae protruding outward from the base body
floor section. For reasons of space these can then also be at least
partially angled upwards. Only with very short side walls should
side lamellae not be provided, because only a little heat can be
absorbed in the short stub base body sides, and therefore
dissipated.
[0023] Because here the heat source to be cooled, here the LED
module, has multiple fastening devices, i.e. holes, in a special
arrangement, these should also be provided in the base body floor
section. The Fortimo module, for example, provides three anchor
holes, arranged in the shape of an isosceles triangle.
[0024] It is particularly advantageous if, in addition to the
customary three holes (two in the front, one in the centre rear) an
additional three holes are provided, which are arranged in a mirror
image of the first three, namely a centre hole on the front outer
edge and two holes spaced apart from each other on the inside edge
of the base body. So the base body can simply be turned by
180.degree. on an LED module and fastened so that the LED module
can either be mounted with its electrical connection side facing
outward, or inward, across from the entire element. This is
particularly the case when using the cooling element not only for
the rectangular Fortimo LED modules for example, but also for the
Lexel modules by Philips having the same width, however, approx.
double the length. The base body can be placed on the module so
that it locks with the outer end of the LED module on the front
side, whereby then, for example, the power-connection side of the
LED module protrudes over the inner edge of the base body far
inwards, in the direction of the cooling body. In this arrangement,
the hot zone is found in the module zone facing the electric
connection end. With a changed application of the module, with the
power connection part facing outward, the thermal conducting base
body of the cooling element sits on the then inner zone so that the
front side of the base body is flush with the corresponding front
side of the LED module.
[0025] With an arrangement with an internal power connection of the
LED module it is important to ensure that a corresponding inner
distance between the base body and the cooling body exists. This
can be achieved, among other things, by using the heat pipes
reversed, namely with the Crimp-end, unusable for a form-locking
contact with the lamellae not protruding far out of the last
lamella, but instead with this and laid into the groove of the base
housing. In this way the entire lamellae package of the cooling
body can be fastened very close to the now outward facing flat
end.
[0026] With a further embodiment at least one, preferably two
support sheets spaced apart from each other provided for the
vertical support of the cooling body. As a result, the entire
cooling lamellae package of the cooling body is carried through
only three heat pipes protruding from the base body. The heat pipes
are mostly manufactured out of relatively soft material with good
thermal conductivity, like aluminum, or copper, and bend very
easily under the weight of the lamellae package, or through
improper handling, and are therefore easily damaged.
[0027] The support sheets can simply lie flat or linear on the
underside, or bottom edge, of the lamellae for support. However,
they can also, in a particularly advantageous manner, join in a
form-fit corresponding vertical slits in the lamella, so that not
only a vertical, but also a good lateral support exists. The
support sheet can be designed in various ways, particular its
length, whereby its first end can be attached to the sides of the
module of the base body, while a second console-type protruding
longer end should at least extend across the majority of the length
of the cooling body.
[0028] It is advantageous if the support sheets are on the top side
designed in the length of the corresponding contact facing the
lamellae and are angled toward the top, with slope, or incline.
There even a slight incline of preferably 5.degree., or at most
18.degree., is already extremely effective, because the entire
lamellae package with heat pipes then runs angled toward the top
directed towards the cooling end, whereby the condensate transport
is supported by gravitational force. Using only a slight slope of
the heat pipes a significantly faster return of the cooled medium
takes place within the heat pipes to the first, hot vaporization
end. Thereby, through an extremely simple measure, a remarkably
better cooling effect can be achieved, paired with increased
strength and safety. For example, for the their application on
non-square heat sources, with larger length measurements and
reverse layout, i.e. with the electrical power connections of the
heat source, or the light housing not facing out, but instead
facing in facing the lamellae cooling body, the distance between
the base body and the lamellae cooling body can be designed at
least 10 mm larger than for square LED modules.
[0029] Finally, it is advantageous if at least the lamellae or even
all parts of the cooling element are executed in black because
black surfaces radiate more heat than white, or bare metal
surfaces.
[0030] In the following, the invention is explained using
embodiments with reference to the drawing, to which it is in no way
limited. Therein show:
[0031] FIG. 1: a perspective view of a first embodiment of the
cooling element from above.
[0032] FIG. 2: a perspective view of the embodiment of FIG. 1 from
below,
[0033] FIG. 3: a perspective view from the front and above a second
embodiment with longitudinal lamellae of the base body,
[0034] FIG. 4: a view from below of the embodiment according to
FIG. 3,
[0035] FIG. 5: a forward front view of the embodiment according to
FIGS. 3 and 4.
[0036] FIG. 6: a perspective view from above and behind of a third
embodiment with oval cooling lamellae and only a short encompassing
cooling body,
[0037] FIG. 7: a perspective view from below the embodiment
according FIG. 6,
[0038] FIG. 8: a perspective view from below the embodiment
according to FIGS. 6 and 7,
[0039] FIG. 9: a forward front view of the embodiment according to
FIG. 6 through 8,
[0040] FIG. 10: a front view of an embodiment similar to that in
FIG. 6, however, without base body sides,
[0041] FIG. 11: a front view of an embodiment similar to FIG. 6,
however, with thick base body-base body floor section,
[0042] FIG. 12: a front view of a lamella of the cooling body in
accordance with the embodiment according to FIG. 6,
[0043] FIG. 13: a side view of the lamellae according to FIG. 12
with the spacer.
[0044] FIG. 14 a schematic side view of the cooling element, placed
on a LED module and light housing, designed with angled support
braces,
[0045] FIG. 15 a schematic side view of a cooling element, placed
on a square LED module,
[0046] FIG. 16 a view similar to FIG. 15, whereby the cooling
element is placed on a long LED module, with inward facing power
connection;
[0047] FIG. 17 a similar arrangement as in FIG. 16 with long LED
module, with outward facing power connection;
[0048] FIG. 18 an embodiment with arrangement of the cooling body
above the LED module, in perspective view;
[0049] FIG. 19 the embodiment of FIG. 18 in cross section
[0050] FIG. 20 the embodiment of FIG. 18 in perspective view from
behind
[0051] FIG. 21 the embodiment of FIG. 18 in view from front
[0052] FIG. 22 the embodiment of FIG. 18 viewed from the base
plate
[0053] FIG. 23 the embodiment of FIG. 18 in view from the back
[0054] FIG. 24 an embodiment of a cooling lamella with adhesive
groove
[0055] FIG. 25: a further embodiment of the cooling body in
different views
[0056] FIG. 26: an embodiment for cooling lamella bodies for a
point light source in perspective view
[0057] FIG. 27: top views of the cooling lamella body from FIG.
26
[0058] FIG. 28: an embodiment of a point light-cooling body with
fastener for cooling lamella body from FIGS. 26 and 27; and
[0059] FIG. 29 a-c Detail views of a point light-cooling
lamella
[0060] In FIGS. 1 and 2 a first embodiment of the invention is
shown, from which it is apparent, that the cooling element 1
according to the invention, consists primarily of three elements, a
base body 2, a cooling body 3, and heat pipes 4, 5, and 6. The heat
pipes 4, 5, and 6 connect the two bodies 2, 3. The heat pipes
initially run inside the base body 2 with, at least, small distance
from one another, whereby the first end section of the heat pipes
4, 5, and 6 is embedded in the base body 2, while the second end
section extends through the cooling body 3. The base body 2 is, in
this embodiment, primarily U-shaped, with a base body floor section
7, and two base body sides 8. Obviously in the base body floor
section 7 of the base body 2 three holes 9 separated from one
another are provided, in which the first end sections of the heat
pipes 4, 5, and 6 run. The LED module 12, which, at the same time,
represents the heat source to be cooled off, is, in this case,
square (i.e. a Fortimo module by Philips). Its body is comprised of
two U-shaped housing parts: a metal housing part 13 and a plastic
housing part 14. The metal housing part 13 has an upward facing
base body floor section 15, with the hot zone 16 (hot spot) in its
centre upon which metal base body sides 17, with corresponding
outer contact surfaces extend on the opposite ends. Here, three
fastening bores 18 are shown which are arranged in a triangle shape
and fasten it to the base body 2. Thereto three threaded holes 19
are arranged in a triangular shape corresponding to the three
fastening bores 18, in the LED module 12.
[0061] Further it is shown that the cooling element 1 has a
relatively long cooling body of cooling body lamellae 20 on its
other end. Here, the cooling body lamellae 20 are simple squares
and are lined up at spaced at a constant distance from one another
on the heat pipes 5, 6.
[0062] The heat pipes 4, 5, and 6 are guided across the entire
length, parallel to each other, with relatively small space in
between in the base body, base body floor section 7 and exit from
the inner side of the base body 2 with corresponding distance.
Concurrently therewith the middle heat pipe 4 runs in the centre,
straight and axially, while both of the outer heat pipes 5 and 6
are first angled diagonally outward, then again run parallel to one
another at a corresponding larger distance from one another, so
that the shape of a fork with three teeth is achieved. The cooling
body lamellae 20 of the cooling body 3 are lined up on the fork
teeth section.
[0063] In FIG. 2, the LED module 12 to be connected with the base
body 2 is shown from above in perspective view as it is laid into
base body 2 and screwed to it. Its plastic housing part 14 faces
upward and in its floor, or light part 24, three fastening bores 18
can also be identified. The contact surface 15 of the U-shaped
metal housing is in assembled state precisely on the contact
surface 21 of the base body 2 while the metal base body sides 17
are in thermal contact with the contact surfaces 22 of the base
body side 17.
[0064] FIG. 3 shows a second embodiment of a cooling element 25.
Both base body sides 8 of the U-shaped base body 2 extend
vertically relatively far down, until nearly over the entire side
length of the LED module to be accommodated. It is particularly
noticeable that the cooling ribs or lamellae 10 are not arranged
cross-wise but instead lengthwise, or axially. On the top side of
the base body floor section 8 vertical, upwardly extending lamellae
10 are provided across the entire length of the base body 2, while,
on the base body sides 8, two side lamellae 28 each, protruding
diagonally upwards, in order to avoid making the protrusion too
expansive are provided. The lengthwise arrangement of the lamellae
28 has the advantage that, with the integral embodiment of the base
body 2, according to the invention, the base body 2 can be extruded
in a faster and more economical manner, whereby even the grooves
for the heat pipes 4, 5, 6 can also be shaped along with it, and
the base body 2 only needs to be cut by a long profile section and
the necessary fastening bores 18 made.
[0065] As a particularity it should be understood that three heat
pipes are no longer provided, but instead only two, namely heat
pipes 5 and 6, which correspond to the shape and arrangement of
this in FIG. 1, whereby both heat pipes 5 and 6 have a shape
similar to a tuning fork with two parallel teeth. What cannot be
identified is that a change in the dimensions of the heat pipes has
taken place here. Here, the preference is no longer to use three
heat pipes with a 5 mm diameter, but instead two heat pipes with a
6 mm diameter so that, despite, the savings of the centre heat
pipe, the stability and the thermal budgeting, meaning the heat
dissipation, in this case, have largely remained unchanged.
Regarding the formation of the cooling body 3 it should be noted
that the cooling body lamellae 20, in comparison to those from FIG.
1, no longer exhibit a simple square shape, but instead are curved
upward in the centre in a dome shape and, in each case, are angled
laterally upward. The height of the cooling body lamellae 20 has
remained the same throughout. The width of the lamellae package is
only very minimally decreased, at the most by a few millimetres, as
a result of the curved and/or angled design. Two punched holes 29
can also be identified, which can be manufactured by a primarily
U-shaped punching and bending back one tongue each by 90.degree.
(not shown in this view), which serve as spacers 32 between the
individual cooling body lamellae 20. Their formation and
arrangement can be better taken from FIGS. 6 and 13 and is also
explained accordingly in connection with these images.
[0066] In addition, two slits 30 are introduced vertically from the
bottom to the top on the cooling body lamellae 20, whereby here
only one of the two slits is shown. The vertical insertion slots
each serve to include a support sheet, as seen in FIGS. 8 and 14
and is also described in connection with these images.
[0067] FIG. 4 shows the cooling element 25 from FIG. 3 in a view
from below, whereby it can be seen that in the base body 2 near the
axial middle, two grooves 26 are provided, in which the, here on
the left, (vaporization) end sections of the heat pipes 5 and 6 are
incorporated along their entire length. In this position these pipe
ends are, for example, held tight by firmly screwing the
corresponding inserted LED module to the base body. The three
thread holes 19 serve this purpose. Here it may be seen how the
side lamellae 28 protrude laterally angled from the deeply downward
drawn base body sides 8 of the base body.
[0068] In cooling body 3 two backwards bent spacers 32 can be seen,
each of which appear as only an axial line, so that an optical
illusion of a line, which could represent a continuous plate,
exists.
[0069] The front view of the cooling element 25 in FIG. 5 allows to
identify the arrangement of the device parts to one another and
their extension in horizontal and vertical directions. So, the
U-shape of the base body 2, with relatively thin base body floor
section 7, is easily recognizable, which is arched around both heat
pipes 5, 6 so that each U-shaped groove 26 is available
corresponding to the diameter of the heat pipes 5, 6. On the top
side of the base body floor section 7 the lengthwise lamellae 10
protrude vertically, and are graded, arched in a cross direction in
their vertical length for a more agreeable appearance and more
convenient handling. This arch continues up to both side lamellae
28. The rounded form of the cooling body lamellae 20 (20b) is
easily recognizable with a centre arch and lateral, upward
extending wing parts. Here it may be seen that the cooling body
lamellae 20 are primarily equally high throughout.
[0070] FIG. 6 through 9 show a third embodiment of the cooling
element 35 according to the invention. In particular, from FIG. 6,
which shows a perspective view from behind, it can be identified
that the base body 2 in its primary elements is put together
similarly to the cooling element 25 from FIG. 3. In this embodiment
the base body sides 8 are rather short. It is the preferred
embodiment for the Fortimo-Moduln, which have a length of only
approx. 5 or 8 millimetres. Also, there are not side lamellae
provided on these short base body sides 8, but instead the cooling
body 2 only has vertically, upward ly extending lamellae 10. Here,
the cooling body lamellae 20 (20c) have a particular design. They
are no longer just square, or designed as a curved and bent square,
as they have no corners at all anymore, but instead a primarily
oval, rounded shape. Although the cooling body lamellae 20c are a
little shorter than the previously described cooling body lamellae
20a and 20b, they do, however, have a significantly larger height,
and width then these, as is particularly evident from the
comparison of the front views according to FIGS. 5 and 9. There is
therefore, with a significantly larger vertically upward heat
dissipation surface, no more space required, however, in the width
there is significant space saved, whereby the installation and
handling are significantly improved. That there are no corners
present on the lamellae package of the cooling body, but instead
only curves which lie comfortably in the hand and also makes it
look better, also adds to these characteristics.
[0071] The rear view of the cooling body 3 from FIG. 6 shows how
both spacers 32 protrude vertically out of the last lamellae 20c,
through which the primarily U-shaped slits in the lamella plate and
subsequent bending of the punched out tongues result, whereby the
punched holes 29 remain open. In addition, it shows how the outer
two ends of both heat pipes 5 and 6 protrude out of the surface of
the last lamella 20 c. The relatively far-protruding heat pipe
section is the respective crimp end 33 of the pipes which exhibit
pinching and therefore are not sufficiently cylindrical in this end
area for proper form-fit accomodation of the lamellae.
[0072] FIG. 7 illustrates the bottom side of the cooling element
35, whereby the arrangement of the slits 30 and the punched holes
29 to the spacers shown may be seen on the cooling body 2. In
addition the embodiment of both heat pipes 5 and 6 is easily
recognized, namely the relatively close guidance in the base body
floor section 7, which after exiting takes on a outwardly curved
arched shape and is then guided with a larger distance parallel to
one another in cooling body 3.
[0073] Further, the arrangement here of the threaded holes 19 is
identified, which serves for the attachment to the LED module.
Here, not only are just the three threaded holes 19 planned in a
triangle arrangement, but instead, in addition, a mirror image
duplication of this arrangement, i.e. six holes. This has the
advantage that the LED module can be mounted to the base body in
any way, i.e. rotated by 180.degree., meaning that a choice exists
whether the power connection will face outward, or inward.
[0074] The particular arrangement of the threaded holes can also be
identified in FIG. 8, a view from below. Here the successive
arrangement of the spacers 32 can also be recognized, similar to
FIG. 4, the guidance and formation of both heat pipes 5 and 6, as
well as the arrangement of the support sheets 36 and 37. The latter
are, on the one hand, fastened to base body 2 and, on the other
hand, reach into the slits 32, which are not showne here, but are,
however, as shortly mentioned in the preceding, in connection with
FIGS. 3, 6, and 7.
[0075] FIG. 9 illustrates the already mentioned arrangements and
size ratios of the individual parts of the cooling element 35, in
particular the cooling body 2 with its relatively thin base body
floor section 7, whose arched grooves 26 guide the heat pipes 5 and
6. How both heat pipes 5 and 6 lie in direct contact with the hot
zone 16 of an LED module 12 can also be identified. Further, the
cloud-like, oval, grooved design of the cooling body lamellae 20c
of cooling body 3, in arrangement and width, as well as height
design, is also visible. Also, both slits 30, for the support
sheets (not shown), as well as the punched holes 29 of the tongue
shaped spacer 32, are visible, from each of which a narrow base
body base, or lower connection base, can be seen.
[0076] FIG. 10 shows a front view of a base body 2 similar to FIG.
9, in which, however, the base body sides are missing and the
straight base body floor section 7 is designed as a plate with
cooling ribs.
[0077] FIG. 11 shows an additional embodiment of base body 2 in
front view with the grooves 26 for both heat pipes 5, 6 as well as
the arrangements and direction of the base body lamellae 10. The
essential difference is the thickness of the base body floor
section 7, similar to the cooling element 1 in FIG. 1. However,
here the heat pipes do not run in lengthwise holes, but instead in
15 U-shaped grooves open to the contact surface. Naturally, this
embodiment with the thick base body floor section 7 can also be
implemented without base body side 8, therefore, primarily as
designed as a plate with a smooth bottom side, similar to the
embodiment of FIG. 10.
[0078] FIG. 12 depicts a lamella 20 of cooling element 35, whose
cloud-like, oval design, which is, in the broadest sense, evocative
of a peanut with its top and bottom longitudinal, symmetric
pinches, or notches. The arrangement of both slits 30 for support
sheets, holes 38 in the lamella for guiding the heat pipes, as well
as the punched out holes 39, can be seen. This concerns a very
simple and cost-effective producible punched part which can be
quickly and simply produced in the quantity desired. Furthermore,
it should be noted that the holes 38 are spaced from one another,
and to the upper and lower edges, so that a ratio of lower height
to upper height of preferably approx. 2: 3.5 exists, and
sufficiently lower free space width remains to ensure good air
circulation despite the great height of the lamellae, as is
particularly evident in FIG. 9.
[0079] FIG. 13 shows, in side view, the lamella 20c from FIG. 12
and the shape of the spacer 36 bent vertically out of it.
[0080] FIG. 14 presents a cooling element 25, 35 implemented in a
LED module 12 on a lamp case 39. The longitudinally extending
support sheets 36 are fastened on the sides of the body 2 by screws
41. The support sheets 36 have a rising angle of, for example
3.degree. to 5.degree. on the upper edge. This way, on one hand the
lamellae package is supported longitudinally, so that the
relatively soft and therefore malleable heat pipes 5 and 6 are
protected longitudinally and horizontally. On the other hand,
because of the angle increase to the back of the lamellae, a
positive angle of "warm side" to "cold side" ensues after
installation. This allows the reflux of the condensate to be
supported by gravitational force and thereby the degree of
effectiveness of the device is measurably improved.
[0081] The power connection 41 of the LED module 12 points
backwards, whereby a cable 42 leads to a connection box 43 of a LED
generator 44. Through the slight angulation of the lamellae package
some more lower space results, so that the corresponding
connections can be formed to the back more easily and without
disturbance.
[0082] FIG. 15 to 17 show different configuration possibilities for
the cooling elements 1, 25, 35, especially of the base body 2
versus the right-angled LED module. Through their arrangement of
the power connection to the front in direction of the lamellae
package, various special problems or challenges arise . . . .
[0083] FIG. 15 shows a configuration similar to FIG. 14, in which a
base body 2 rests on a quadratic LED module 12 of the same length.
The hot upper zone 16 of the LED module 12 as well as its light
zone 24 is in the middle of the LED module 12 and the base body 2.
The power connection 40 points to the back of the lamellae of the
cooling element 3. Because for this embodiment there is a
relatively large distance between the back of the base body 2 and
the front lamella of the cooling element 3, there is no space
problem and the connection can be handled easily.
[0084] In FIG. 16, the configuration of the base body 2 of a device
accordancing to the invention, on a relatively long LED module can
be seen; the electrical connection faces the back, whereby the hot
zone 16 and the light zone 24 are located in the front half of the
LED module. Accordingly, the base body 2 is also located on this
front side and is aligned with its front side. The inner distance
between the base body and the cooling body is so large, that there
is sufficient room for the power connection 40 to the first
lamellae of the cooling body. The additional space is achieved
through the total lamellae package of the cooling body 3 on the
heat pipes being pushed further out. In addition, the heat pipes
with the crimp ends are not jutting out to the right, but rather
the crimp-ends (that represent a missing length) are situated in
the notches of the base body 2, so that the lamellae package can be
configured all the way outside on the smooth end 34 of the heat
pipes. This allows 10 mm of distance to be gained when the tubes
and the cooling body lengths are the same.
[0085] FIG. 17 shows the cooling element from FIG. 15, 16 with a
rotated, long LED module whose power connection 40 is easily
accessible from the front. Because the hot zone 16 is located on
the side facing the cooling-frame lamellae, the base body 2 is
located on this back zone of the LED module so that both back sides
of the base body and the LED module are vertically aligned.
[0086] FIG. 18 shows a further embodiment for the cooling element
for a heat source for locations where the height of the cooling
element is unimportant, but where space must be saved horizontally.
These designs are particularly suitable for hanging lights and
similar. Here, the heat pipes (for these designs 2 heat pipes are
presented) are bent in one level into U-shape so that the cooling
body is located above the LED housing. The embodiment is shown in
cross-section in FIG. 19 for better understanding.
[0087] FIG. 20 to 23 show further views of the embodiment with the
cooling bodies above the LED. It is obvious how the heat pipes lead
from the base body 2 into the cooling body 3 and how the heat pipes
6,5 feed into notches in the base body 2. The base body 2 is an
extruded profile in this design and is easy to manufacture.
[0088] FIG. 24 shows a preferred embodiment of cooling a lamella
20, which enables a particularly strong connection of the cooling
body lamellae 20 to the heat pipes. To this end, in addition to the
form or press fit between the lamellae 20 and the heat pipe, a
deepened peripheral surface area of the entry opening for the heat
pipe is provided in the opening 38 area; for example, by deep
drawing with a form stamp after cutting the lamellae. The
ring-shaped groove 45 formed between heatpipe and lamella opening
serves to take in the connection between material helping the
connection between the heat pipe and the lamellae--e.g. adhesives,
soldering material, or filling materials. Heat-conducive adhesives
which are known to the expert in the field are preferred.
[0089] Especially suited are adhesives including admixed
heat-conducive metals. Through the adhesive layer ring around the
heat pipe made in this way, the mechanical and thermal connection
of the heat pipe on the lamellae 20 is improved.
[0090] FIG. 25 exemplifies a further embodiment of a cooling
element 3 with a relatively thick base body floor section, short
sidewalls and reception openings 6 for heat pipes in the base body
section from different views.
[0091] FIG. 26 presents a further embodiment in accordance with the
invention for small light sources, such a spotlight light sources.
Spotlight light sources are light sources with a small outer
circumference that project light in a targeted fashion. They can
often be pivoted in order to follow changing objects, which need to
be illuminated in order to highlight them optically. These
spotlights have a slim construction above the light source. In this
example, a special cooling lamellae body 3 with a small diameter is
shown for a spotlight. The cooling body lamellae 20 are bent in a
wing-like fashion, so that they have a small diameter when seen
from below and so that behind the actual light source, the LED,
they are less optically apparent. It is important to maintain
appropriate distances between the lamellae--secured by the
spacer--in order to make air circulation possible. The bent
lamellae wings are currently preferable attached at an angle of 30
to 60 degrees to the heat pipe, preferably between 40 and 50
degrees, in order to make optimal air circulation possible for
cooling.
[0092] In FIG. 27 views from above and below the cooling lamellae
frame 2 of the FIG. 26 are shown in the direction of the central
opening. In the view from above (FIG. 27a), the bent lamellae 50 of
the base body are clearly visible; at the same time, in the view
from below (FIG. 27b), the fastening screws for a LED and the bent
lamellae 50 can be seen, as well as the minimal optical view of the
body.
[0093] In FIG. 28 an example of the spotlight base frame 2 for the
design of FIG. 27 is shown. The fastening above the indentation
provided in the lamellae for the heat pipes of the cool lamellae
body in FIG. 26 and FIG. 27 is presented and the outline is based
on a circular LED. In FIG. 29 detailled views of a spotlight
cooling lamella 50 are presented. The central opening for air
circulation, the bent spacers, the openings for the heat pipes are
clearly visible. A detailed view of the spacer, which here is
formed into a support 32a, as well of a heat pipe receiving area
with a groove 45 is shown.
[0094] Even though the invention was explained in detail with a
preferred embodiment, it is in no way limited to this design but is
only determined by the protection of the accompanying claims.
REFERENCE LIST
[0095] 1. Cooling element, first design. [0096] 2. Base body [0097]
3. Cooling body [0098] 4. Heat pipe [0099] 5. Heat pipe [0100] 6.
Heat pipe [0101] 7. Floor section [0102] 8. Base body side [0103]
9. Hole [0104] 10. Lamellae (base body-) [0105] 11. Fastening hole,
side [0106] 12. LED-Module (heat source) [0107] 13. Metal housing
part [0108] 14. Plastic housing part [0109] 15. Floor
section--contact surface [0110] 16. Hot zone (hot-spot) [0111] 17.
Metal housing part--base body side [0112] 18. Fastening hole [0113]
19. Threaded hole [0114] 20. Lamellae (cooling body) [0115] 21.
Floor section contact surface [0116] 22. Base body contact surface
[0117] 24. Light zone (-floor) [0118] 25. Cooling element, second
design [0119] 26. Groove [0120] 27. Arch [0121] 28. Side lamellae
[0122] 29. Punched hole [0123] 30. Slit [0124] 32. Spacer [0125]
33. Crimp-End of 4, 5 [0126] 34. Smooth end of 4, 5 [0127] 35.
Cooling element, third design [0128] 36. Support sheet [0129] 37.
Support sheet [0130] 38. Hole [0131] 39. Lamp housing [0132] 40.
Power connection [0133] 41. Fastening screw [0134] 42. Cable [0135]
43. Connection box [0136] 44. LED generator [0137] a Angle
* * * * *