BACKGROUND OF THE INVENTION
1. Technical Field
The invention relates to heat pipes, particularly to vapor chambers.
2. Related Art
Vapor chambers are a variant type of heat pipe. Because of lightness and thinness, vapor chambers are widely applied in portable electronic apparatuses.
A conventional vapor chamber includes a casing, wick structure, working fluid and filling/degassing tube. The casing has a chamber therein. The wick structure and working fluid are disposed in the chamber. The filling/degassing tube is connected with the casing and protrudent from the chamber. The filling/degassing tube is used for filling the working fluid into the casing and degassing the air in the casing. After that, the filling/degassing tube have to be sealed by welding.
When a vapor chamber is installed in an electronic apparatus, the protrudent filling/degassing tube usually interferes with other components or mechanisms. This may limit availability of vapor chambers. Further, the protrudent filling/degassing tube tends to be damaged by unexpected collisions or pressure when assembling.
SUMMARY OF THE INVENTION
An object of the invention is to provide a vapor chamber, which is easy to make a sealed end of the filling/degassing tube and avoids the tube from interfering with other components by the tube with the casing.
To accomplish the above object, the vapor chamber of the invention includes a casing, wick structure, working fluid and filling/degassing tube. The casing is composed of two plates and has a chamber therein. The wick structure and working fluid are disposed in the chamber. The filling/degassing tube is connected with the casing to form a passage communicating with the chamber. A portion of the plates which overlaps the filling/degassing tube is pressed to deform for making the passage closed. And the outer end of the filling/degassing tube is flush with the side of the casing.
An advantage of the invention is to provide an option of the second cutting, which may increase availability of vapor chambers. Besides, the manufacturing cost and process can also be reduced and simplified, respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the invention;
FIG. 2 is a perspective view of the invention before the filling/degassing tube is machined;
FIG. 3 is a cross-sectional view of the invention before the filling/degassing tube is pressedly machined;
FIG. 4 is a cross-sectional view of the invention after the filling/degassing tube is pressedly machined;
FIG. 5 is a cross-sectional view of the invention before the filling/degassing tube is cut;
FIG. 6 is a perspective view of another embodiment of the invention; and
FIG. 7 is a cross-sectional view of the embodiment shown in FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
Please refer to FIG. 1. The vapor chamber of the invention includes a casing 10, a wick structure 20, a working fluid 30 and a filling/degassing tube 40.
The casing 10 is made of copper or copper alloy. In this embodiment, the casing 10 is composed of an upper plate 11 and a lower plate 12. Each of the two plates 11,12 is of a substantially rectangular shape. A periphery of the overlapping plates 11,12 is sealed by welding to form a chamber 13 therein. An angle of the casing 10 is formed with a truncated angle 14. The upper plate 11 is arced at the truncated angle 14 to form an insert channel 15 which communicates with the chamber 13.
The wick structure 20 may be metal mesh, fiber bundle or sintered metal powder. It is attached on the plates 11,12 in the chamber 13. The wick structure 20 provides a capillary force to make liquid working fluid 30 flow back.
The work fluid 30 may be water and is filled in the chamber 13. Under a room temperature, the work fluid 30 is liquid absorbed in the wick structure 20. The work fluid 30 will be vaporized to flow upwards.
The filling/degassing tube 40 has a semicircular cross-section. A portion of the filling/degassing tube 40 is inserted into the insert channel 15 and firmly connected therewith, and the other portion is exposed and protrudent from the plates 11,12. The filling/degassing tube 40 is provided with a passage 41 which communicates with the chamber 13.
Please refer to FIGS. 2-5. After the work fluid has been filed in the chamber 13 of the casing 10 and the air in the chamber 13 has been removed out, A press machine is employed to press the upper plate 11 at the location of filling/degassing tube 40. As a result, the upper plate 11 and the filling/degassing tube 40 will be deformed to make the passage 41 closed and to form a groove 16 in the upper plate 11. In the shown embodiment, the groove 16 has a U-shaped cross-section. After that, a knife 8 as shown in FIG. 5 is employed to cut a portion of the filling/degassing tube 40 which is protrudent from the truncated angle 14 of the casing 10. This can flush an outer end of the filling/degassing tube 40 and the casing 10.
Please refer to FIGS. 6 and 7, which illustrate another embodiment of the invention. The knife 8 may be used to perform a second cut to the groove 16 in the above embodiment to form a new groove 16′. The new groove 16′ has a substantially L-shaped cross-section. This may further decrease a size of the filling/degassing tube 40 to expand availability in small apparatuses.
It will be appreciated by persons skilled in the art that the above embodiments have been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the invention as defined by the appended claims.