Patent Publication Number: US-6662863-B2

Title: Structure of heat exchanger tank

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a connection structure of a metallic tank for use in a heat exchanger of automobiles, etc. 
     2. Description of the Related Arts 
     The conventional heat exchanger metallic tank is provided with an elongated box-shaped tank body having an open end, and a tube plate adapted to block the open side. The tank body is manufactured through a plurality of deep drawing steps by means of press machines. 
     In case of manufacturing the tank body through the plurality of press drawing steps, a plurality of dedicated molds are needed increasing the cost for the manufacture of the molds, which results in a higher price of the heat exchanger as a whole. 
     When the tube plate is fitted and brazed to the tank body opening, the fitting portions at corners, esp., of the tank body and the tube plate may not necessarily be in registration with each other. This is attributable to a possible spring back or the like in the press forming. As a result, a leak may occur from the fitting portion at the corners after brazing. 
     SUMMARY OF THE INVENTION 
     It is therefore the object of the present invention to overcome the above deficiencies. 
     In order to attain the above object, according to a first aspect of the present invention there is provided a heat exchanger tank structure comprising: 
     a tank body formed from a bent metal plate in the shape of an elongated groove, the tank body having a bottom and two parallel sidewalls; 
     a tube plate having an open side which confronts the bottom of the tank body, the open side adapted to securely be fitted to the tank body; 
     the bottom of the tank body having one or more first slits formed over the full width of the bottom in a parallel relationship in the width direction; and 
     a metallic reinforcement member having an outer periphery which conforms to the contour of the tank body, the reinforcement member having at its top a slit fitting portion which mates with the first slit, the reinforcement member having at its both sides a pair of second slits into which the two sidewalls are inserted; 
     wherein the top of the reinforcement member is fitted in the first slit of the tank body, with the pair of second slits of the reinforcement member clamping both sides of the tank body, to thereby provide a liquid-tight connection therebetween. 
     According to a second aspect of the present invention there is provided a heat exchanger tank structure comprising: 
     a tank body formed from a bent metal plate in the shape of an elongated groove, the tank body having a bottom and two parallel sidewalls; 
     a tube plate having an open side which confronts the bottom of the tank body, the open side adapted to securely be fitted to the tank body; 
     the bottom of the tank body having, at its intermediate portion in the longitudinal direction, one or more intermediate first slits formed over the full width of the bottom in a parallel relationship in the width direction; and 
     a metallic reinforcement member in the shape of a gate in plan having at its top a slit fitting portion adapted to mate with the intermediate first slit, the reinforcement member including two legs having a pair of intermediate second slits into which the two sidewalls of the tank body are inserted; 
     wherein the top of the reinforcement member is fitted in the intermediate first slit of the tank body, with the pair of intermediate second slits of the reinforcement member clamping both sides of the tank body, to thereby provide a liquid-tight connection therebetween. 
     According to a third aspect of the present invention there is provided a heat exchanger tank structure comprising: 
     a tank body formed from a bent metal plate in the shape of an elongated groove, the tank body having a bottom and two parallel sidewalls; 
     a tube plate in the shape of a shallow groove having an open side which confronts the bottom of the tank body, the open side adapted to securely be fitted to the tank body; 
     the bottom of the tank body having a pair of end first slits formed over the full width of the bottom in a parallel relationship in the width direction; and 
     a pair of reinforcement side lids having an outer periphery which conforms to the grooved-shaped section of the tank body, the pair of reinforcement side lids each having at its bottom edge a slit fitting portion which mates with corresponding one of the pair of end first slits, the pair of reinforcement side lids each having a pair of end second slits which receive the sidewalls of the tank body, the pair of reinforcement side lids each having a protrusion formed on an edge confronting the tube plate; 
     the tube plate having a pair of locking holes formed in the tube plate at its opposite ends, the locking hole adapted to mate with the protrusion; 
     wherein the top of each of the pair of reinforcement side lids is fitted in corresponding one of the pair of end first slits such that the pair of end second slits clamp the two sidewalls of the tank body and that the protrusions are fitted in the locking holes of the tube plate, to thereby provide a liquid-tight connection therebetween. 
     The first slit may extend through the full width of the bottom of the tank body and, contiguous therewith, through a part of the two sidewalls in the region of the bottom, and the second slit may be inserted through the edges of the first slit associated with the sidewalls into the tube plate. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects, aspects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: 
     FIG. 1 is an exploded perspective view of a heat exchanger tank structure in accordance with the present invention; 
     FIG. 2 is a side view of the principal part, showing the assembled state of the tank structure; and 
     FIG. 3 is a perspective view of another embodiment of a reinforcement member for use in the tank structure. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will now be described with reference to the accompanying drawings which illustrate preferred embodiments thereof in a non-limitative manner. 
     FIG. 1 is an exploded perspective view of a tank structure in accordance with the present invention, and FIG. 2 is a side view of the principal part, showing the assembled state. 
     This heat exchanger tank structure comprises a tank body generally designated at  3  and formed from a bent aluminum or other metal plate, having a bottom  1  and a pair of sidewalls  2  opposing in its width direction. The tank structure further comprises a tube plate generally designated at  4 , in the shape of a shallow groove, securely fitted to the opening which confronts the bottom  1  of the tank body  3 . The tube plate  4  includes a multiplicity of tube insertion apertures  13  juxtaposed in its longitudinal direction, and a pair of locking holes  12  disposed at opposite ends thereof. 
     The tank body  3  has at the middle in its longitudinal direction one or more intermediate first slits  5  which are formed in parallel in the width direction through the full width of the bottom  1  and are extended through a part of the sidewalls. The tank body  3  has at opposite ends in its longitudinal direction a pair of end first slits  5   a  which also extend through the full width of the bottom  1  and through a part of the sidewalls  2 . 
     A reinforcement member  9  is fitted to the intermediate first slit  5 . The reinforcement member  9  has a thickness equal to the width of the intermediate first slit  5 . The reinforcement member  9  is in the shape of a gate including two legs  7  having respective intermediate second slits  8  which are fitted on the sidewalls  2  at slit edges associated with the intermediate first slit  5  so as to clamp the corresponding sidewalls. 
     A reinforcement side lid  11  is fitted in the end first slit  5   a  positioned at the opposite ends of the tank body  3 . The reinforcement side lid  11  has a thickness equal to the width of the end first slit  5   a . The reinforcement side lid  11  has a pair of end second slits  8   a  formed along opposite edges in the width direction, the pair of end second slits  8   a  being fitted on the sidewalls  2  at slit edges associated with the end first slits  5   a  so as to clamp the corresponding pair of sidewalls  2 . The reinforcement side lid  11  has at its bottom a protrusion  10  which is in registration with the locking hole  12  of the tube plate  4 . 
     One of the pair of the sidewall  2  is provided with a pipe connection opening which receives one end of the pipe  15 . The multiplicity of tube insertion apertures  13  of the tube plate  4  receive ends of corresponding number of flat tubes  14 . Corrugated fins not shown are disposed in regions between adjacent tubes  14 . Such components can be ones at least one of which in contact with each other has a surface coated with a brazing material. 
     &lt;Assembling Method&gt; 
     The reinforcement member  9  is fitted and positioned in the intermediate first slit  5  of the tank body  3  such that its intermediate second slit  8  can clamp both sides of each of the pair of sidewalls  2 . The reinforcement side lid  11  is fitted and positioned in the end first slit  5   a  disposed in the tank body  3  at its opposite ends in the longitudinal direction such that its end second slit  8   a  can clamp the inner and outer surfaces of each of the pair of sidewalls  2 . The thus assembled tank body  3  is then mounted on the tube plate  4  such that the protrusions  10  of the reinforcement side lids  11  fit in the corresponding locking holes  12 . The multiplicity of tubes  14  are previously inserted from their ends through the corresponding tube insertion apertures  13 , with the fins arranged between the adjacent tubes. 
     The thus assembled heat exchanger is inserted as a whole into a furnace at a high temperature so that the coated brazing material is fused and then cooled and solidified to finally provide integral brazing between components. 
     Reference is then made to FIG. 3 which illustrates another embodiment of the reinforcement member  9  for use in the present invention. In this example, the flat surface of the reinforcement member  9  includes a plurality of air vents  16  arranged at proper locations. When the reinforcement member  9  is fitted in the intermediate first slit  5  of the tank body  3 , the plurality of air vents  16  are positioned on the inside of the tank body  3 . The plurality of air vents  16  serve to allow air to freely flow through the interior of the tank body  3  by way of the air vents  16  when there occurs air accumulation within the interior of the tank body  3 . 
     This is in particular needed for the upper tank when the heat exchanger is used as an engine coolant cooling radiator. 
     The heat exchanger tank structure of the present invention allows the tank body  3  and the reinforcement member to be connected together in a liquid-tight fashion, with the reinforcement members being fitted in the first slits at the bottom  1  of the tank body  3 , the second slits of the reinforcement member clamping both sides of the tank body  3 , thus making it possible to reinforce the sidewalls and definitely position the distance between the pair of sidewalls. This leads to an increased pressure resistance, capability to strictly specify the relative dimensions of the bottom  1  and the tube plate  4 , and improved reliability of the connection between the two. 
     According to the invention defined in claim  2 , the reinforcement for the tank body can be effected at the intermediate portion of the tank body. 
     According to the invention defined in claim  3 , the reinforcement side lids  11  are fitted in the pair of end first slits  5   a  in the bottom  1  at the opposite ends of the tank body  3  in the longitudinal direction, with the end second slits  8   a  of each reinforcement side lid  11  clamping the sidewalls  2  of the tank body  3  for connection, whereby it is possible to definitely specify the opposed distance between the pair of sidewalls at the opposite ends of the tank body  3  in the longitudinal direction and to achieve the conformability with the tube plate  4  to thereby improve the brazing reliability. 
     By virtue of fitting of the protrusions  10  of the reinforcement side lids  11  into the locking holes  12  of the tube plate  4  for locking , the tank body  3  is prevented from rising from the tube plate  4  upon connection. The tank body  3  itself can be manufactured only by bending and slit forming the metal plate without needing the deep drawing, thus resulting in a simplified mold for the sidewalls  2  and consequently in a reduction of the manufacturing costs. Similarly, the tube plate  4  itself can be of a shallow groove type, which contributes to a simplification of the molds and to a further reduction of the manufacturing costs. 
     While illustrative and presently preferred embodiments of the present invention have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art.