Heat pipe and method for manufacturing the same

Abstract

A heat pipe includes a metallic pipe, a wick structure and a working fluid. The interior of the metallic pipe has a sealing chamber, and is formed into an evaporating section, an adiabatic section and a condensing section along its lengthwise direction. The wick structure comprises a first wick structure and two elongate second wick structures connected to the first wick structure. The first wick structure is adhered to the inner wall of the evaporating section. The two second wick structures are separated from each other and adhered to the inner walls of the evaporating section, the adiabatic section and the condensing section. A gas channel is formed between the two second wick structures, and has a smooth surface. The working fluid is filled in the sealed chamber. By this arrangement, the space for the gas channel can be enlarged, thereby accelerating the flowing speed of the internal gas and enhancing the heat-conducting efficiency of the heat pipe.

1 . A heat pipe, comprising:
 a metallic pipe with an interior thereof having a sealed chamber, the metallic pipe being formed into an evaporating section, an adiabatic section and a condensing section along a lengthwise direction thereof;   a wick structure comprising a first wick structure and two elongate second wick structures connected to the first wick structure, the first wick structure being adhered to an inner wall of the evaporating section, the two second wick structures being separated from each other and adhered to an inner walls of the evaporating section, the adiabatic section and the condensing section, a gas channel being formed between the two second wick structures, the gas channel having a smooth surface; and   a working fluid filled in the sealed chamber.   
     
     
         2 . The heat pipe according to  claim 1 , wherein the heat pipe is a flat heat pipe. 
     
     
         3 . The heat pipe according to  claim 2 , wherein the heat pipe is enclosed by the two flat plates and two curved plates. 
     
     
         4 . The heat pipe according to  claim 3 , wherein the first wick structure is formed on the flat plate. 
     
     
         5 . The heat pipe according to  claim 3 , wherein the second wick structure is formed on the curved plate. 
     
     
         6 . The heat pipe according to  claim 2 , wherein an outer surface of the evaporating section protrudes to form a protrusion, an interior of the protrusion is formed with a trough, and the first wick structure is filled in the trough. 
     
     
         7 . The heat pipe according to  claim 6 , wherein the wick structure is made by sintering metallic powder. 
     
     
         8 . A method for manufacturing a heat pipe, comprising the steps of:
 a) providing a metallic pipe with a sealed end;   b) inserting a core rod into the metallic pipe, a portion of the circumference of the core rod being adhered to an inner wall of the metallic pipe, a pitch being formed between the other portion of a circumference of the core rod and the inner wall of the metallic pipe;   c) filling metallic powder into the metallic pipe through the pitch;   d) sintering the metallic powder;   e) removing the core rod, forming inside the metallic pipe with a first wick structure and two elongate second wick structures connected to the first wick structure, a gas channel being formed between the two second wick structures, the gas channel having a smooth surface; and   f) filling a working fluid in the metallic pipe, degassing and sealing the metallic pipe.   
     
     
         9 . The method according to  claim 8 , wherein a circular metallic pipe is pressed by a forming die to form a flat profile in the step a), and the flattened metallic pipe is enclosed by two flat plates and two curved plates. 
     
     
         10 . The method according to  claim 9 , wherein an outer surface of the flat plate is formed with a protrusion, and an inside of the protrusion is formed with a trough. 
     
     
         11 . The method according to  claim 10 , wherein a rectangular core rod is inserted into the metallic pipe in the step b), upper and lower surfaces of the core rod are clamped by the inner walls of the two flat plates so as to be adhered to each other, a pitch is formed between the left and right surfaces of the core rod and the inner walls of the two curved plates, and the pitch is in communication with the trough. 
     
     
         12 . The method according to  claim 11 , further comprising a step g) of leveling the protrusion by means of a forming device. 
     
     
         13 . The method according to  claim 9 , wherein a rectangular core rod having a concave surface is inserted into the metallic pipe in the step b), upper and lower surfaces of the core rod are clamped by the inner walls of the two flat plates so as to be adhered to each other, the pitch is formed between the left and right surfaces of the core rod and the inner walls of the two curved plates, the metallic pipe is formed with an accommodating trough corresponding to the concave surface, the accommodating trough is in communication with the pitch. 
     
     
         14 . The method according to  claim 8 , wherein metallic powder of small particles is filled in a bottom section of the metallic pipe in the step c), and then metallic powder of larger particles is filled in the middle and upper sections of the metallic pipe.