U.S. patent application number 14/180410 was filed with the patent office on 2015-04-30 for heat pipe with ultra-thin capillary structure.
The applicant listed for this patent is Hao PAI. Invention is credited to Hao PAI.
Application Number | 20150114604 14/180410 |
Document ID | / |
Family ID | 51009606 |
Filed Date | 2015-04-30 |
United States Patent
Application |
20150114604 |
Kind Code |
A1 |
PAI; Hao |
April 30, 2015 |
HEAT PIPE WITH ULTRA-THIN CAPILLARY STRUCTURE
Abstract
A heat pipe with an ultra-thin capillary structure includes a
tube body which is hollow and flat, and a capillary structure which
is in the tube body and is shaped as a thin plate. The capillary
structure has an adhering surface attached on a partial portion of
an inner wall of the tube body, and a forming surface corresponding
to the adhering surface. A vapor channel formed between the forming
surface and the inner wall of the tube body; wherein the forming
surface further includes an abutting surface elongated along a
longitudinal direction of the vapor channel and at least one
capillary transmission surface extending from a side of the
abutting surface to connect to the adhering surface the steam
channel, and the capillary transmission surface is gradually
inclined between the adhering surface and the abutting surface.
Inventors: |
PAI; Hao; (Taoyuan County,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PAI; Hao |
Taoyuan County |
|
TW |
|
|
Family ID: |
51009606 |
Appl. No.: |
14/180410 |
Filed: |
February 14, 2014 |
Current U.S.
Class: |
165/104.26 |
Current CPC
Class: |
F28D 15/046 20130101;
F28D 15/0233 20130101 |
Class at
Publication: |
165/104.26 |
International
Class: |
F28D 15/04 20060101
F28D015/04 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 29, 2013 |
TW |
102139178 |
Claims
1. A heat pipe with an ultra-thin capillary structure, comprising:
a tube body (1), being hollow and flat; and a capillary structure
(2), being in the tube body (1) and shaped as a thin plate, having
an adhering surface (20) attached on a partial portion of an inner
wall of the tube body (1), and a forming surface (21) corresponding
to the adhering surface (20), a vapor channel (100) being formed
between the forming surface (21) and the inner wall of the tube
body (1); wherein the forming surface (21) further comprises an
abutting surface (210) elongated along a longitudinal direction of
the vapor channel (100), and at least one capillary transmission
surface (211) extending from a side of the abutting surface (210)
to connect to the adhering surface (20), the capillary transmission
surface (211) being gradually inclined between the adhering surface
(20) and the abutting surface (210).
2. The heat pipe with an ultra-thin capillary structure according
to claim 1, wherein a thickness of the flat tube body (1) is under
0.5 mm.
3. The heat pipe with an ultra-thin capillary structure according
to claim 1, wherein the capillary structure (2) is made by
selecting from a group consisting of knit, fiber and sintered metal
powders and their combination.
4. The heat pipe with an ultra-thin capillary structure according
to claim 1, wherein a porosity of the forming surface (21) is
gradually reduced as the forming surface (21) is extended toward
the adhering surface (20).
5. The heat pipe with an ultra-thin capillary structure according
to claim 1, wherein two sides of the abutting surface (210) have
two capillary transmission surfaces (211), respectively.
6. The heat pipe with an ultra-thin capillary structure according
to claim 5, wherein the two capillary transmission surfaces (211)
are symmetrical to each other.
7. The heat pipe with an ultra-thin capillary structure according
to claim 1, wherein a bare area (22) is formed at a portion of the
capillary structure (2) by removing corresponding capillary
transmission surface.
8. The heat pipe with an ultra-thin capillary structure according
to claim 1, wherein the capillary transmission surface (211) has a
plurality of air flow holes (220) exposing the inner wall of the
tube body (1).
9. The heat pipe with an ultra-thin capillary structure according
to claim 1, wherein the capillary transmission surface (211) has a
plurality of cut-outs (220') exposing the inner wall of the tube
body (1).
10. The heat pipe with an ultra-thin capillary structure according
to claim 1, wherein the capillary structure (2) has a plurality of
grooves (101) that are radially threaded on the inner wall of the
tube body (1), a depth of the groove (101) being less than 30% of a
thickness of the tube body (1).
11. The heat pipe with an ultra-thin capillary structure according
to claim 10, wherein the depth of the thread (101) is less than
0.03 mm.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to a miniaturized
heat pipe, more particularly to a heat pipe with an ultra-thin
capillary structure.
[0003] 2. Description of the Prior Art
[0004] Nowadays, electronic products are tending to small volumes
in order to be easily carried. Since the volumes are smaller, some
kinds of electronic products that need to dissipate heat inside
should focus on the issue of the volume of a heat pipe. In order to
minimize the heat pipe in the electronic products, an ultra-thin
heat pipe, which has thickness under 1.5 mm, is then developed.
[0005] However, a capillary structure inside the ultra-thin heat
pipe shall follow the design tendency to be smaller as well. To
design the capillary structure, it may focus on the inner space of
a heat pipe in order to avoid that the inner space is too small to
let air or fluid be through. That is, when an ultra-thin heat pipe
is manufactured in a sintering process, its volume is designed very
small to cause that metal powders are not able to be through a gap
between a mandrel bar and the inner wall of the ultra-thin heat
pipe, and part of the metal powders may not be positioned in the
ultra-thin heat pipe. That is why a powdered capillary structure of
an ultra-thin heat pipe is only formed at a location of the heat
pipe without completion in prior arts. As a conclusion, a sectional
surface of an ultra-thin heat pipe is hardly filled with the
powdered capillary structure in prior arts. As it can be seen, this
kind of powdered capillary structure may be short of a better
vaporization surface area, a better condensation surface area, a
better liquid transmission sectional surface area, a fluent vapor
channel, and a reinforced supporting structure, and we would know
the prior ultra-thin heat pipe should be improved in the aspect of
heat transmission.
[0006] Accordingly, how to improve the heat transmission of an
ultra-thin heat pipe in prior arts is an important issue to the
people skilled in the art.
SUMMARY OF THE INVENTION
[0007] In one aspect, the present invention is to provide a heat
pipe with an ultra-thin capillary structure. It is to form a
miniaturized capillary structure on an inner wall of a heat pipe in
order to maintain an enough space of a vapor channel for heat
exchange, for example vaporization and condensation. Furthermore,
the heat pipe has a largest capillary surface area and a liquid
transmission sectional area, so as to approach the aspect with a
miniaturized heat pipe.
[0008] In order to perform the above aspect, a heat pipe with an
ultra-thin capillary structure provided by the present invention
comprises a tube body which is hollow and flat, and a capillary
structure which is in the tube body and is shaped as a thin plate.
The capillary structure has an adhering surface attaching on a
partial portion of an inner wall of the tube body, and a forming
surface corresponding to the adhering surface. A vapor channel is
formed between the forming surface and the inner wall of the tube
body; wherein the forming surface further comprises an abutting
surface elongated along a longitudinal direction of the vapor
channel and at least one capillary transmission surface extending
from a side of the abutting surface to connect to the adhering
surface , and the capillary transmission surface is gradually
inclined between the adhering surface and the abutting surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The objects, spirits, and advantages of the preferred
embodiments of the present invention will be readily understood by
the accompanying drawings and detailed descriptions, wherein:
[0010] FIG. 1 illustrates a schematic perspective view according to
the present invention;
[0011] FIG. 2 illustrates a schematic cross-sectional view of a
section 2-2 of FIG. 1 according to the present invention;
[0012] FIG. 3 illustrates a schematic cross-sectional view of a
second embodiment according to the present invention based on a
view direction of FIG. 2;
[0013] FIG. 4 illustrates a schematic perspective view of a third
embodiment according to the present invention;
[0014] FIG. 5 illustrates a schematic perspective view of a fourth
embodiment according to the present invention;
[0015] FIG. 6 illustrates a schematic perspective view of a fifth
embodiment according to the present invention; and
[0016] FIG. 7 illustrates a schematic partial and enlarged
sectional view inside a tube body of the fifth embodiment according
to the present invention;
DETAILED DESCRIPTION OF THE INVENTION
[0017] Following preferred embodiments and figures will be
described in detail so as to achieve aforesaid objects.
[0018] Please refer to FIG. 1 and FIG. 2, which illustrate a
schematic perspective view and a schematic cross-sectional view of
a section 2-2 of FIG. 1 according to the present invention. The
present invention provides a heat pipe with an ultra-thin capillary
structure. The heat pipe comprises a tube body 1 that is hollow and
flat, and at least one capillary structure 2 that is in the tube
body 1 and contacts with partial inner walls of the tube body 1.
The tube body 1 is formed by a pressing process, and is a flat type
with a thickness under 0.5 mm. When the tube body 1 is formed, the
tube body 1 comprises an upper wall 10, a lower wall 11, and a
plurality of side edges 12, wherein the upper wall 10 and the lower
wall 11 are arranged corresponding to each other, and the side
edges 12 are connected between the upper wall 10 and the lower wall
11.
[0019] As shown in FIG. 2, the capillary structure 2 is disposed in
the tube body 1. The capillary structure 2 is made by knit, fiber,
sintered metal powders, or any of their combination, in order to
form a shape of thin plate. Prior to dispose the capillary
structure 2 in the tube body 1, the capillary structure 2 is made.
As a matter of fact, the capillary structure 2 is placed in the
tube body 1 and simultaneously pressed with the tube body 1. The
capillary structure 2 has an adhering surface 20 attached on a
partial portion of an inner wall of the tube body 1, and a forming
surface 21 with a continuous concave arc corresponding to the
adhering surface 20. As aforesaid, the adhering surface 20 is
positioned on the partial portion of the inner wall, for example
the inner surface of the lower wall 11, of the tube body 1. After
the tube body 1 is pressed to be flat, the inner wall, for example
the inner surface of the upper wall 10, of the tube body 1 abuts on
a partial portion of the forming surface 21 of the capillary
structure 2. Continuously, a vapor channel 100 is formed between
the rest portion of the forming surface 21 and the upper wall 10,
the inner wall 11, and one of the side edges 12 inside the tube
body 1. In particular, the adhering surface 20 is elongated along a
longitudinal direction of the vapor channel 100, and a porosity of
the forming surface 21 is gradually reduced as the forming surface
21 is extended toward the adhering surface 20. Factor in the
formation of the porosity feature of the forming surface 21 is that
the capillary structure 2 is extruded by the pressing process.
[0020] In the preferred embodiment of the present invention, the
forming surface 21 has an abutting surface 210 that is attached on
the inner surface of the upper wall 10 and elongated along a
longitudinal direction of the vapor channel 100, and at least one
capillary transmission surface 211 that extends from a side of the
abutting surface 210 to connect to the adhering surface 20. In
particular, the capillary transmission surface 211 is gradually
inclined between the adhering surface 20 and the abutting surface
210. The benefits of the inclined capillary transmission surface
211 are to increase a surface area between the capillary structure
2 and the vapor channel 100, reduce flow resistance of vapor flow,
and increase a capillary surface area of working fluid flowing back
to the capillary structure 2, in order to achieve a better
heat-exchange rate, even though the capillary structure 2 is
thinned. As it can be seen, the present invention discloses that
two sides of the capillary structure 2 form the two vapor channels
100 and the two capillary transmission surfaces 211, respectively.
As shown in FIG. 3, the two capillary transmission surfaces 211 of
the capillary structure 2 can be asymmetrical, but in FIG. 2, there
is a symmetrical arrangement.
[0021] As shown in FIG. 4, the capillary structure 2 is formed with
at least one bare area 22. In particular, at a portion of the
capillary structure, the capillary transmission surface 211 formed
at the one side or both capillary transmission surfaces 211
respectively formed at two sides of the forming surface 21 are
removed to separately form one or more bare areas 22. Besides, the
bare areas 22 can be formed at a transmission section between a
vaporizing section and a condensation section of a heat pipe.
Furthermore, the capillary transmission surface 211 can have a
plurality of air flow holes 220 exposing inner surface of the lower
wall 11 of the tube body 1, in order to increase a capillary
transmission area. As shown in FIG. 5, instead of forming the round
air flow holes 220, there are a plurality of cut-outs 220' formed
on each capillary transmission surface 211.
[0022] As shown in FIG. 6 and FIG. 7, there are a plurality of
grooves 101 that are radially threaded, in right helical direction,
left helical direction, or both, or even irregularly, on the inner
wall of the tube body 1. A depth of the groove 101 is less than
0.03 mm, and is usually less than 30% of a thickness of the tube
body 1 as well, as shown in FIG. 7. As it can be seen, since the
grooves 101 are formed on the inner surface of the tube body 1, the
structure of the grooves 101 will not interfere the formation of
the vapor channel 100. Meanwhile, the grooves 101 are radially
threaded to surrounding on the inner wall of the tube body 1, the
liquid working fluid can flow back to the capillary structure 2; on
the other hand, the liquid working fluid flowing back axially
(along the longitudinal direction) is through the capillary
structure 2 as well. Therefore, the grooves 101 can provide
auxiliary help to the capillary structure 2 to form a capillary
transmission net that totally covers totally the inner wall of the
tube body 1.
[0023] Accordingly, by means of above described structure, a heat
pipe with an ultra-thin capillary structure is achieved.
[0024] Although the invention has been disclosed and illustrated
with reference to particular embodiments, the principles involved
are susceptible for use in numerous other embodiments that will be
apparent to persons skilled in the art. This invention is,
therefore, to be limited only as indicated by the scope of the
appended claims.
* * * * *