U.S. patent application number 13/730623 was filed with the patent office on 2014-06-05 for heat pipe and method for manufacturing the same.
This patent application is currently assigned to FOXCONN TECHNOLOGY CO., LTD.. The applicant listed for this patent is FOXCONN TECHNOLOGY CO., LTD., FURUI PRECISE COMPONENT (KUNSHAN) CO., LTD. Invention is credited to SHENG-LIANG DAI, JIA-HONG WU.
Application Number | 20140150995 13/730623 |
Document ID | / |
Family ID | 50824283 |
Filed Date | 2014-06-05 |
United States Patent
Application |
20140150995 |
Kind Code |
A1 |
DAI; SHENG-LIANG ; et
al. |
June 5, 2014 |
HEAT PIPE AND METHOD FOR MANUFACTURING THE SAME
Abstract
An exemplary heat pipe includes a hollow tube, a wick structure
configured on an inner surface of the tube and a working medium
formed in the tube. Two ends of the tube are sealed and the tube
defining a chamber therein. The tube comprises an evaporating
section and a condensing section, and the evaporating section is
isolated from the condensing section. The wick structure extends
from the evaporating section to the condensing section along the
inner surface of the tube to form a working medium channel. A pair
of through holes is defined in each of the evaporating section and
the condensing section of the tube. A pair of metal pipes
communicate the through holes of the evaporating section with those
of the condensing section to form a pair of vapor channels. A
method for manufacturing the heat pipe is also provided.
Inventors: |
DAI; SHENG-LIANG; (Kunshan,
CN) ; WU; JIA-HONG; (New Taipei, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LTD; FURUI PRECISE COMPONENT (KUNSHAN) CO.,
FOXCONN TECHNOLOGY CO., LTD. |
New Taipei |
|
US
TW |
|
|
Assignee: |
FOXCONN TECHNOLOGY CO.,
LTD.
New Taipei
TW
FURUI PRECISE COMPONENT (KUNSHAN) CO., LTD.
Kunshan
CN
|
Family ID: |
50824283 |
Appl. No.: |
13/730623 |
Filed: |
December 28, 2012 |
Current U.S.
Class: |
165/104.26 ;
29/890.032 |
Current CPC
Class: |
F28D 15/046 20130101;
F28D 15/0266 20130101; Y10T 29/49353 20150115; F28D 15/04
20130101 |
Class at
Publication: |
165/104.26 ;
29/890.032 |
International
Class: |
F28D 15/04 20060101
F28D015/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 4, 2012 |
CN |
201210510719.0 |
Claims
1. A heat pipe comprising a hollow tube, two ends of the tube being
sealed and the tube defining a chamber therein; a wick structure
provided on an inner surface of the tube; and a working medium
provided in the chamber; wherein the tube comprises an evaporating
section and a condensing section, the evaporating section is
isolated from the condensing section, the wick structure extends
from the evaporating section to the condensing section along the
inner surface of the tube to form a working medium channel, a
through hole is defined in each of the evaporating section and the
condensing section of the tube, and a metal pipe communicates the
through hole of the evaporating section with the through hole of
the condensing section, respectively, to form a vapor channel.
2. The heat pipe of claim 1, further comprising a metal layer
therein, wherein the evaporating section is isolated from the
condensing section by the metal layer, the metal layer comprises a
tapered portion and a cylindrical portion connected to a right end
of the tapered portion, the tapered portion tapers from the
evaporating section to the condensing section until the tapered
portion terminates at a closed end thereof, and the tapered portion
and the cylindrical portion are attached to the wick structure of
the tube.
3. The heat pipe of claim 2, wherein the tube further comprises a
reduced section between the evaporating section and the condensing
section, the reduced section is located outside the metal layer,
the evaporating section and the condensing section of the tube have
a same inner diameter and a same outer diameter which constitute an
inner diameter and an outer diameter of the tube, respectively, and
an inner diameter and an outer diameter of the reduced section are
less than the inner diameter and the outer diameter of the tube,
respectively.
4. The heat pipe of claim 3, wherein the reduced section has a
middle portion and two end portions located at two ends of the
middle portion, an inner diameter and an outer diameter of the
middle portion are constant, the inner diameter and the outer
diameter of the middle portion are less than the inner diameter and
the outer diameter of the tube, respectively, and an inner diameter
and an outer diameter of each end portion increases along a
direction away from the middle portion until the inner diameter and
the outer diameter of the end portion are equal to the inner
diameter and the outer diameter of the tube, respectively.
5. The heat pipe of claim 1, wherein a length of the evaporating
section is less than that of the condensing section.
6. The heat pipe of claim 1, wherein the tube is made of thermally
conductive material.
7. The heat pipe of claim 1, wherein the wick structure is selected
from the group consisting of fine grooves, sintered powder, screen
mesh, and bundles of fiber.
8. A method for manufacturing a heat pipe, the method comprising:
providing a tube with a wick structure on an inner surface thereof,
the tube defining a chamber therein, and further defining an
evaporating section and a condensing section; insolating the
evaporating section from the condensing section by blocking the
chamber, the wick structure extending from the evaporating section
to the condensing section along the inner surface of the tube to
form a working medium channel; evacuating the evaporating section
and the condensing section, injecting a working medium into the
tube, and sealing the tube; defining at least one through hole in
each of the evaporating section and the condensing section of the
tube; and arranging at least one metal pipe to communicate the at
least one through hole of the evaporating section with the at least
one through hole of the condensing section, thereby defining at
least one vapor channel.
9. The method of claim 8, wherein insolating the evaporating
section from the condensing section further comprises: providing a
metal layer in the tube between the evaporating section and the
condensing section, the metal layer being attached to the wick
structure of the tube; pressing the tube at the metal layer to
obtain a reduced section of the tube, an inner diameter and an
outer diameter of the reduced section being less than an inner
diameter and an outer diameter of the tube, respectively, one
portion of the metal layer in the reduced section tapering in a
direction from the evaporating section to the condensing section
until terminating at a closed end of said one portion, another
portion of the metal layer in the evaporating section remaining
attached to the wick structure of the tube, the evaporating section
thereby being insolated from the condensing section by the metal
layer.
10. The method of claim 9, wherein the reduced section has a middle
portion and two end portions located at two ends of the middle
portion, an inner diameter and an outer diameter of the middle
portion are constant and both less than that of the tube, and an
inner diameter and an outer diameter of the end portion increase
along a direction away from the middle portion until the inner
diameter and the outer diameter of the end portion being equal to
that of the tube.
11. The method of claim 8, wherein the tube is made of thermally
conductive materials.
12. The method as claimed in claim 8, wherein the wick structure is
selected from fine grooves, sintered powder, screen mesh, and
bundles of fiber.
13. The method of claim 8, wherein a length of the evaporating
section is less than that of the condensing section.
14. A heat pipe comprising a hollow tube, two ends of the tube
being sealed and the tube defining a chamber therein; a wick
structure provided on an inner surface of the tube; and a working
medium provided in the chamber; wherein the tube comprises an
evaporating section and a condensing section, the evaporating
section is isolated from the condensing section, the wick structure
extends from the evaporating section to the condensing section
along the inner surface of the tube to form a working medium
channel, two through holes are defined in each of the evaporating
section and the condensing section of the tube, and two metal pipes
communicate the two through holes of the evaporating section with
the two through holes of the condensing section, respectively, to
form two vapor channels.
15. The heat pipe of claim 14, further comprising a metal layer
therein, wherein the evaporating section is isolated from the
condensing section by the metal layer, the metal layer comprises a
tapered portion and a cylindrical portion connected to a right end
of the tapered portion, the tapered portion tapers from the
evaporating section to the condensing section until closed, and the
tapered portion and the cylindrical portion are attached to the
wick structure of the tube.
16. The heat pipe of claim 15, wherein the tube further comprises a
reduced section between the evaporating section and the condensing
section, the reduced section is located outside the metal layer,
and an inner diameter and an outer diameter of the reduced section
are both less than that of the tube respectively.
17. The heat pipe of claim 16, wherein the reduced section has a
middle portion and two end portions located at two ends of the
middle portion, an inner diameter and an outer diameter of the
middle portion are constant, and the inner diameter and outer
diameter of the middle portion both less than that of the tube, and
an inner diameter and an outer diameter of the end portion increase
along a direction away from the middle portion, until the inner
diameter and the outer diameter of the end portion being equal to
that of the tube.
18. The heat pipe of claim 14, wherein a length of the evaporating
section is less than that of the condensing section.
19. The heat pipe of claim 14, wherein the tube is made of
thermally conductive materials.
20. The heat pipe of claim 14, wherein the wick structure is
selected from fine grooves, sintered powder, screen mesh, and
bundles of fiber.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The present invention relates generally to heat pipes and
methods for manufacturing heat pipes.
[0003] 2. Description of Related Art
[0004] Currently, heat pipes are widely used for removing heat from
heat-generating components such as electrical devices in computers.
A heat pipe includes a sealed tube held in vacuum but also
containing a working medium therein. The working medium is employed
to carry, under phase transitions between a liquid state and a
vapor state, thermal energy from an evaporator section to a
condenser section of the heat pipe. Preferably a wick structure is
provided inside the heat pipe, lining an inner wall of the tube,
for drawing the working medium back to the evaporator section after
it is condensed at the condenser section. In a traditional heat
pipe, a vapor channel is defined in a middle of the tube, with the
wick structure surrounding the vapor channel. The vapor flows along
the vapor channel in a longitudinal direction, and the liquid
working medium flows in the wick structure reversely. A shear
stress is generated between the vapor and the liquid working medium
when they are flowing, and the shear stress reduces the heat
transferring performance of the heat pipe.
[0005] Therefore, a heat pipe and a method for manufacturing the
heat pipe which are capable of overcoming the above described
shortcomings are desired.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Many aspects of the present embodiments can be better
understood with reference to the following drawings. The components
in the drawings are not necessarily drawn to scale, the emphasis
instead being placed upon clearly illustrating the principles of
the present embodiments. Moreover, in the drawings, like reference
numerals designate corresponding parts throughout the several
views.
[0007] FIG. 1 is a longitudinal cross-sectional view of a heat pipe
in accordance with a first embodiment of the present invention.
[0008] FIGS. 2-7 are schematic, cross-sectional views showing
sequential steps of an exemplary method for manufacturing the heat
pipe of FIG. 1.
[0009] FIG. 8 is a longitudinal cross-sectional view of a heat pipe
in accordance with a second embodiment of the present
invention.
DETAILED DESCRIPTION
[0010] Referring to FIG. 1, a heat pipe 1 in accordance with a
first embodiment of the present invention includes a hollow tube 10
with a wick structure 11 configured on an inner surface of the
hollow tube 10. Two ends of the tube 10 are sealed, so that the
tube 10 defines a chamber 12 therein. A working medium is provided
in the chamber 12. The tube 10 is symmetrical along a central axis
thereof.
[0011] The tube 10 forms a reduced section 13 at an intermediate
position thereof. The tube 10 includes an evaporating section 14
and a condensing section 15 located adjacent to two ends of the
reduced section 13, respectively. The evaporating section 14 is
isolated from the condensing section 15, and a length of the
evaporating section 14 is less than that of the condensing section
15. An inner diameter and an outer diameter of the evaporating
section 14 are equal to those of the condensing section 15,
respectively. The reduced section 13 has a middle portion 131, and
two end portions 132 located at two ends of the middle portion 131,
respectively. An inner diameter and an outer diameter of the middle
portion 131 are constant, and both the inner and outer diameters
are less than those of the evaporating section 14. An inner
diameter and an outer diameter of each end portion 132 respectively
increase along a direction away from the middle portion 131, until
the inner diameter and the outer diameter of the end portion 132
are equal to those of the corresponding evaporating section 14 or
condensing section 15, respectively.
[0012] The tube 10 has a metal layer 16 formed therein, and the
metal layer 16 is symmetrical about the central axis of the tube
10. The metal layer 16 includes a tapered portion 161 and a
cylindrical portion 162 connected to a right end of the tapered
portion 161. The tapered portion 161 tapers from the cylindrical
portion 162 (in a direction from the evaporating section 14 to the
condensing section 15) until the tapered portion 161 terminates at
a closed, pointed end. In this embodiment, the tapered portion 161
of the metal layer 16 is a hollow tapered portion. The tapered
portion 161 is parallel to a right one of the end portions 132, and
abuts the wick structure 11 of the right end portion 132. Thus, a
right section of the tapered portion 161 is attached to the wick
structure 11 of the right end portion 132. In addition, the
cylindrical portion 162 of the metal layer 16 is attached to the
wick structure 11 of the evaporating section 14. Accordingly, the
chamber 12 of the tube 10 is divided into two parts by the metal
layer 16, with the two parts corresponding to the evaporating
section 14 and the condensing section 15.
[0013] The wick structure 11 extends from the evaporating section
14 to the condensing section 15 along the inner surface of the tube
10, thereby forming a working medium channel. Two through holes 17
are defined in each of the evaporating section 14 and the
condensing section 15 of the tube 10. Two hollow metal pipes 18 are
provided. One of the hollow metal pipes 18 communicates one of the
through holes 17 of the evaporating section 14 with one of the
through holes 17 of the condensing section 15 at a same side of the
tube 10. The other hollow metal pipe 18 communicates the other
through hole 17 of the evaporating section 14 with the other
through hole 17 of the condensing section 15 at another same side
of the tube 10. Thereby, two vapor channels 181 are defined by the
hollow metal pipes 18.
[0014] In operation, the evaporating section 14 of the heat pipe 1
is put in thermal contact with a heat generating electronic
component (not shown). The working medium in the heat pipe 1 is
vaporized after receiving the heat generated by the heat generating
electronic component, and the vapor exerts pressure on the metal
layer 16. However, the tapered portion 161 of the metal layer 16
tapers in the direction from the evaporating section 14 to the
condensing section 15 until the tapered portion 161 terminates at
the closed, pointed end. Accordingly, the vapor is blocked from
moving directly toward to the condensing section 15, and instead
flows to the condensing section 15 via the two vapor channels 181.
The vapor condenses into liquid state working medium slowly as it
flows through the two vapor channels 181, and then flows into the
condensing section 15. Thus, the pressure in the chamber 12 at the
condensing section 15 is decreased. The liquid working medium is
drawn back to the evaporating section 14 by the wick structure 11
provided on the inner surface of the tube 10.
[0015] Therefore the flow of working medium is circulatory along
two closed loops that are joined at the tube 10. The flow of
working medium along each of the loops is essentially
unidirectional, and the flow of working medium along the tube 10
where the loops are joined is also unidirectional. This arrangement
avoids or even completely eliminates shear stress that is liable to
be generated between vapor and liquid working medium when the vapor
and liquid working medium are flowing in opposite directions along
paths that are adjacent to each other. Thus, the heat transferring
performance of the heat pipe 1 can be improved.
[0016] It is understood that in alternative embodiments, the
evaporating section 14 and the condensing section 15 can be
isolated from each other by other means. That is, other heat pipes
are not limited to using the metal layer 16 of the first
embodiment.
[0017] Referring to FIGS. 2-7, an exemplary method for
manufacturing the heat pipe 1 includes steps as described
below.
[0018] Referring to FIG. 2, a tube 20 is provided, with two ends of
the tube 20 being open. The tube 20 is formed with a wick structure
21 on an inner surface thereof, and defines a chamber 22 therein.
In this embodiment, the tube 20 is made of a highly thermal
conductive material such as copper or aluminum. A transverse
cross-section of the tube 20 is a circular ring, and the tube 20
defines a central axis. The wick structure 21 extends along a
longitudinal direction of the tube 20. The wick structure 21 is
usually a porous structure selected from fine grooves, sintered
powder, screen mesh, or bundles of fiber, and provides a capillary
force to drive working medium in the tube 20 to flow.
[0019] Referring to FIG. 3, a cylindrical metal layer 30 is
provided and located in the chamber 22 of the tube 20. The metal
layer 30 is attached to the wick structure 21 of the tube 20. The
metal layer 30 is close to but spaced from a right end of the tube
20. In this embodiment, a length of the metal layer 30 is 20-60 mm
(millimeters), and the metal layer is made of high toughness
material such as copper or aluminum.
[0020] Referring to FIGS. 4 and 5, a portion of the tube 20
containing a left portion of the metal layer 30 is pressed to
obtain a reduced section 40 of the tube 20 containing the pressed
portion of the metal layer 30. Specifically, a compressing tool 50
is provided. The compressing tool 50 may for example include a pair
of opposite pressing dies. The compressing tool 50 is positioned
corresponding to the left portion of the metal layer 30. The
compressing tool 50 compresses the left portion of the metal layer
30 along radial directions of the tube 20 until the left end of the
left portion of the metal layer 30 is closed. Because the metal
layer 30 is made of high toughness material, the metal layer 30
attaches to the wick structure 21 of the tube 20. In this
embodiment, the reduced section 40 divides the tube 20 into the
evaporating section 23 and the condensing section 24, with the
reduced section 40 intervening between the evaporating section 23
and the condensing section 24. Thus, the evaporating section 23 is
isolated from the condensing section 24. A length of the
evaporating section 23 is less than that of the condensing section
24.
[0021] The reduced section 40 has a middle portion 41, and two end
portions 42 located at two ends of the middle portion 41. An inner
diameter and an outer diameter of the middle portion 41 are
constant, and the inner and outer diameters of the middle portion
41 are both less than those of the evaporating section 23. An inner
diameter and an outer diameter of each end portion 42 increase
along a direction away from the middle portion 41, until the inner
diameter and the outer diameter of the end portion 42 are equal to
those of the corresponding evaporating section 23 or condensing
section 15, respectively. The wick structure 21 extends from the
evaporating section 23 to the condensing section 24 along the inner
surface of the tube 20, thereby forming a working medium channel. A
length of the uncompressed cylindrical portion of the metal layer
30 in the evaporating section 23 is 10 mm.
[0022] The tube 20 has a working medium injected into it, and is
evacuated of air and sealed. In particular, both the evaporating
section 23 and the condensing section 24 are evacuated of air.
[0023] Referring to FIG. 6, two pairs of opposite through holes 25
are formed in each of the evaporating section 23 and the condensing
section 24 of the tube 20.
[0024] Referring to FIG. 7, two hollow metal pipes 60 are provided
to communicate the through holes 25 of the evaporating section 23
with those of the condensing section 24, so that two vapor channels
61 are defined by the hollow metal pipes 60. Thus, the heat pipe 1
is manufactured.
[0025] Referring to FIG. 8, a heat pipe in accordance with a second
embodiment of the present invention is shown. There are four pairs
of through holes 25 defined in the tube 20. Four hollow metal pipes
60 are provided to communicate the through holes 25 of the
evaporating section 23 with those of the condensing section 24, so
that four vapor channels 61 are defined by the hollow metal pipes
60. It is understood that the quantity of the through holes 25 and
the hollow metal pipes 60 is not limited to eight through holes 25
and four hollow metal pipes 60.
[0026] Particular embodiments are shown and described by way of
illustration and example only. The principles and the features of
the present disclosure may be employed in various and numerous
embodiments thereof without departing from the scope of the
disclosure. The above-described embodiments illustrate the scope of
the disclosure but do not restrict the scope of the disclosure.
* * * * *