Method and apparatus for forming a turbulizer

Abstract

A turbulizer is formed that has corrugations that each have side walls with openings and offset portions in them. A strip is rolled longitudinally to form a corrugated strip that has longitudinally extending corrugations. Openings and the above-mentioned offset portions are formed in the corrugated strip. An apparatus for forming a turbulizer has one or more pairs of roll dies that have cooperating corrugated profiles that advance strip stock that is engaged between them. These roll dies provide the strip with longitudinally extending corrugations. First and second forming dies receive the corrugated strip and move relative to one another to form pairs of spaced cuts that each define a wall portion between them. This wall portion is displaced transversely of an adjacent portion of the corrugated strip. A fin or turbulizer for a heat exchanger has a strip that has longitudinally extending side edges and longitudinally extending corrugations. There are openings through the corrugations in a region that is intermediate the side edges. An imperforate side edge portion extends between the side edge and the intermediate region. The corrugations extend in a general plane. The imperforate side edge portion inclines with respect to that general plane outwardly away from the intermediate region. The side edge portion may incline with respect to the general plane outwardly away from the intermediate portion and may have a distal portion extending inwardly generally toward the intermediate portion.

1 . Method of forming a turbulizer having corrugations each having side walls with openings and offset portions formed in said side walls, said method comprising: 
 (a) rolling a strip longitudinally to form a corrugated strip having longitudinally extending corrugations; and    (b) forming said openings and said offset portions in said corrugated strip.    
   
   
       2 . Method according to  claim 1  wherein said step of forming said openings and said offset portions in said corrugated strip comprises forming pairs of spaced cuts extending transversely of said corrugated strip, each pair of spaced cuts defining a wall portion between them, and having each said wall portion displaced transversely of an adjacent portion of said corrugated strip.  
   
   
       3 . Method according to  claim 2  wherein the spaced cuts in each pair are spaced uniformly longitudinally apart.  
   
   
       4 . Method according to  claim 2  wherein the pairs of spaced cuts are spaced uniformly longitudinally apart.  
   
   
       5 . Method according to  claim 1  wherein said openings and said offset portions are distributed uniformly continuously along said corrugated strip.  
   
   
       6 . Method according to  claim 1  wherein said openings and said offset portions are at differing spacings along said corrugated strip.  
   
   
       7 . Method according to  claim 1  including a step of severing said corrugated strip transversely into discrete lengths after said step of forming said openings and said offset portions.  
   
   
       8 . Method according to  claim 1  including providing first and second forming dies moving between an open position and a closed position wherein the forming dies engage the corrugated strip between them, said forming dies when moving to said closed position cooperating to form said openings and said offset portions in said corrugated strip.  
   
   
       9 . Method according to  claim 8  including providing at least one pair of roll dies having cooperating corrugated profiles, said roll dies rotatingly driven during intermittent periods and having said strip engaged between said roll dies and said roll dies advancing said strip and providing it with corrugations by its passage between said roll dies, and including passing said strip having said corrugations between said forming dies, and said forming dies moving intermittently to said closed position at roll stationary times intermediate said intermittent periods.  
   
   
       10 . Method according to  claim 8  including providing a train of pairs of roll dies, each of said roll die pairs driven rotatingly synchronously for intermittent periods that are intermediate roll stationary times and having said strip engaged and advanced successively between pairs of roll dies of said train, said roll dies in each pair having cooperating corrugated profiles such that successive pairs of roll dies form said strip with a progressively increasing number of said corrugations, and including exiting said strip from said train between said forming dies, and wherein said forming dies move intermittently to said closed positions at said roll stationary times.  
   
   
       11 . Method according to  claim 1  wherein said strip has a thickness of 0.05 mm to 2 mm.  
   
   
       12 . Method according to  claim 11  wherein said thickness is 0.1 to 0.5 mm.  
   
   
       13 . Apparatus for forming a turbulizer having corrugations each having side walls with openings and offset portions formed in said side walls,  
     said apparatus comprising: 
 at least one pair of roll dies having cooperating corrugated profiles adapted to advance strip stock engaged therebetween and to provide it with longitudinally extending corrugations;  
 first and second forming dies adapted to receive said strip having said corrugations exiting said at least one pair of roll dies;  
 and said first and second forming dies on movement relative to one another forming pairs of spaced cuts each defining a wall portion between them and displacing each wall portion transversely of an adjacent portion of said corrugated strip.  
 
   
   
       14 . Apparatus according to  claim 13  including an operator device operated to move said first and second dies between an open position and a closed position engaging said strip; 
 and including a drive rotating said roll dies during intermittent periods that are intermediate roll stationary times;    and wherein said operator device moves said first and second dies to said closed position during a roll stationary time, and said first and second dies on moving to the closed position are effective to form said pairs of spaced cuts and to displace each said wall portion transversely of an adjacent corrugation portion.    
   
   
       15 . Apparatus according to  claim 14  wherein said first and second dies each have a longitudinal length and said drive is effective to advance said strip stock a distance equal to said longitudinal length in successive intermittent periods.  
   
   
       16 . Apparatus according to  claim 14  wherein said first and second dies each have a longitudinal length and said drive is effective to advance said strip stock a distance greater than said longitudinal length in successive intermittent periods.  
   
   
       17 . Apparatus according to  claim 14  wherein said first and second dies each comprise at least one longitudinal row of punches each comprising a first series of longitudinally spaced punches aligned to a first longitudinal axis, and a second series of longitudinally spaced punches that are disposed alternately between the punches of the first series, said punches in said second series aligned to a second longitudinal axis offset transversely from said first longitudinal axis, said punches of said first die generally opposing and disposed complementarily with respect to said punches of said second die.  
   
   
       18 . Apparatus according to  claim 17  wherein each of said first and second dies is provided with a respective stripper plate normally maintained spaced from the die and having an elongated slot that is penetrated by said at least one longitudinal row of punches in said closed position, and wherein said at least one pair of roll dies has a line of engagement of the rolls constituting said at least one pair, and said line of engagement is aligned with a region disposed between said stripper plates in an open position.  
   
   
       19 . Apparatus according to  claim 18  including yoke structure yoking said stripper plates together.  
   
   
       20 . Apparatus according to  claim 19  including a biasing device biasing said stripper plates normally a distance laterally away from each of said first and second dies.  
   
   
       21 . Apparatus according to  claim 19  wherein said yoke structure provides laterally disposed guide surfaces adapted to guide said corrugated strip in its passage between said stripper plates.  
   
   
       22 . Apparatus according to  claim 13  comprising a train of said pairs of roll dies, said roll dies in each pair having cooperating corrugated profiles such that successive pairs form said strip with a progressively increasing number of said corrugations.  
   
   
       23 . Apparatus according to  claim 13  including a cutter adapted to cut said strip exiting said forming dies into lengths.  
   
   
       24 . A fin or turbulizer for a heat exchanger comprising a strip having longitudinally extending side edges and longitudinally extending corrugations, openings formed through said corrugations in a region intermediate said side edges, an imperforate side edge portion extending between said side edge and said intermediate region, said strip having said corrugations therein extending in a general plane, and said imperforate side edge portion inclining with respect to said general plane outwardly away from said intermediate region.  
   
   
       25 . A fin or turbulizer according to  claim 24  wherein said strip having said corrugations therein has a height dimension defined between a crest of a corrugation on a face of said strip and a crest of a corrugation on an opposite face of said strip, and wherein said side edge portion extends a distance less than said height dimensions.  
   
   
       26 . An inner fin or turbulizer for a heat exchanger comprising a strip having longitudinally extending side edges and longitudinally extending corrugations, a side edge portion extending inwardly from a side edge of the strip toward an intermediate portion thereof, said strip having said corrugations therein extending in a general plane, and said side edge portion inclining with respect to said general plane outwardly away from said intermediate portion and having a distal portion extending inwardly generally toward said intermediate portion.  
   
   
       27 . A fin or turbulizer according to  claim 26  wherein said side edge portion curves smoothly toward said distal portion.  
   
   
       28 . A fin or turbulizer according to  claim 26  wherein said strip having said corrugations therein has a height dimension defined between a crest of a corrugation on a face of said strip and a crest of a corrugation on an opposite face of said strip, and wherein said side edge portion extends a distance less than said height dimensions.