Patent Publication Number: US-2009218073-A1

Title: Cooling fin

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is related to a cooling fin and particularly to a cooling fin, which is capable of increasing turbulent currents and carrying out a great deal of heat source. 
     2. Brief Description of the Related Art 
     The processing speed of the electronic chip increases due to incessantly progress of technology but it leads to increase of the generated heat as well. Nevertheless, the high temperature is a primary reason of the undesirable operation efficiency and burn-out of the chip. Therefore, how to dissipate the heat from the chip for protecting the chip is one of the subjects that are researched and developed currently. 
     In order to obtain the best effect of heat dissipation and promote the heat dissipation efficiency, most researches and developments are focus on the increased conductive area for the heat transmitted by the heat sink and the fan mounted to the heat sink for forcing the airflow. Besides, a plurality of cooling fins being stacked as a cooling fin set in association with guide heat pipes is utilized to promote the heat dissipation efficiency. The respective cooling fin has a flat plate member with two opposite bent edges for engaging with each other. When the fan induces the air to pass through the cooling fin set, the airflow moves fast and it is able to carry a small amount of heat on the cooing fin set only. Hence, the effect of heat dissipation is still limited although it was designed for expecting the good heat transfer with the effective heat dissipation. 
     SUMMARY OF THE INVENTION 
     In order to overcome the deficiencies of the prior art, an object of the present invention is to provide a cooling fin, which get involve the concept of turbulent flow for increasing the stagnation time of the air staying at the respective cooling fin of the cooling fin set and enhancing the efficiency of heat dissipation greatly in addition to increase the area of the heat dissipation. 
     Accordingly, A cooling fin according to the present invention comprises at least a projection part and a slot, which is disposed at the lateral sides, for turning the airflow into the turbulent flow while the air flow passing through the slot and for creating eddy currents at the periphery of the cooling fin. Therefore, the cold air, which flows between a plurality of cooling fins, can stagnate longer time for carrying more heat outward and enhancing the heat dissipation efficiency greatly. 
     Wherein, the protrusion part can be circular or the square shape. Further, a plurality of the protrusion parts can be arranged irregularly on the plate member such that the effect of different eddy currents at the periphery of the cooling fin can be produced advantageously and the slots at the lateral sides of the respective protrusion part are helpful for increasing the coefficient of heat exchange of the cooling fin and enhancing the integral performance of the cooling fin. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The detail structure, the applied principle, the function and the effectiveness of the present invention can be more fully understood with reference to the following description and accompanying drawings, in which: 
         FIG. 1  is a perspective view of a cooling fin according to a preferred embodiment of the present invention; 
         FIG. 2  is an fragmentary perspective view of the cooling fin shown in  FIG. 1  illustrating the square protrusion part; 
         FIG. 3  is a perspective view of a cooling fin according to another embodiment of the present invention; and 
         FIG. 4  is a fragmentary perspective view of the cooling fin shown in  FIG. 3  illustrating the circular protrusion part. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 and 2 , a cooling fin  10  according to the first preferred embodiment of the present invention basically is a plate member  1  with a bent edge  11  at two opposite lateral sides. The bent edge  11  can be provided with an engaging part for joining two plate members  1 . At least a protrusion part  12  is provided on the plate member  1  and the protrusion part  12  is square shape with a slot  121  or a plurality of slots  121  being disposed at each of the lateral sides thereof for guiding the airflows such that the airflows can be turned into the turbulent flows to surround the plate member  1 . In this way, the stagnation time of the airflow can be extended to carry more heat outward for enhancing heat dissipation. 
     Besides, the projection parts  12  can be arranged irregularly at the cooling fin  10  such that the effect resulting from different eddy currents at the periphery of the cooling fin and the slots  121  at the lateral sides of the respective projection part  12  can promote the coefficient of heat exchange of the cooling fin  10  to enhance the integral performance of the cooling fin  10 . 
     Referring to  FIGS. 3 and 4 , another embodiment of a cooling fin for a heat sink according to the present invention is illustrated. Similarly, the cooling fin  10  of the second embodiment basically is a plate member  1  with a bent edge  11  at two opposite lateral sides thereof. The bent edge  11  can be provided with an engaging part for joining two plate members  1 . At least a protrusion part  12  is provided on the plate member  1  and the protrusion part  12  is square shape with a slot  121  or a plurality of slots  121  being disposed at each of the lateral sides thereof for guiding the airflows such that the airflows can be turned into the turbulent flows to surround the plate member  1 . The difference of the respective projection  12  from that shown in  FIGS. 1 and 2  is in that the shape of the respective projection  12  is circular instead of square. In this way, the stagnation time of the airflow can be extended to carry more heat outward for enhancing heat dissipation as well. 
     While the invention has been described with referencing to the preferred embodiments thereof, it is to be understood that modifications or variations may be easily made without departing from the spirit of this invention, which is defined by the appended claims.