US 3703925 A
A tube and fin type heat exchanger core made up of unique and identical plate strip structures having formed extrusions, the extrusions nesting when the plates are stacked to form the tubes and the portions of the plates between the extrusions forming the fins. The extrusions form trough-like projections with a number of holes in the bottoms of the trough-like projections to permit the flow of fluid between the plate structures. The walls of the projections have offset portions to serve as spacing means between the plates. A slight crimp or bend is provided in the plate portion between each extrusion to facilitate the assembly of the plate structures regardless of small deviations in the spacing dimensions between extrusions.
Description (OCR text may contain errors)
United States Patent Ireland et al. 1 1 Nov. 28, 1972 [s 1 HEAT EXCHANGER coma:  Inventors: Robert G. Ireland, Indianapolis; Pfimary Emminerfiedenck L- Manesofl Fred L. Mauls, Greenwood; Ross W. Teeguarden, lndianapolis, all of 1nd.
Karmazin ..l65/150 X Assistant Examiner'lheophil W. Streule AttomeyAugustus G. Douvas, William J. Newman and Norton Lesser  ABSTRACT portions to serve as spacing means between the plates.
A slight crimp or bend is provided in the plate portion between each extrusion to facilitate the assembly of the plate structures regardless of small deviations in the spacing dimensions between extrusions.
2 Clalns, 6 Drawing Figures PATENTEDunvze I972 sum 1 [IF- 2 FIG.3
INVE NTORS Robert G. Ireland Fred L- Munis Ross W. Teeguorden By Atto rnev HEAT EXCHANGER CORE This invention relates to heat exchangers and more particularly to heat exchanger cores of the tube and tin type which include individual plate structures making up the heat exchanger core.
A primary objective of this invention is to provide a very low cost heat exchanger without sacrificing operation efficiencies. Todays rising labor, manufacturing and overhead costs, as well as industrys conversion to automated techniques, dictate the need for a simply constructed heat exchanger, formable with relatively inexpensive materials with a minimum number of com ponents and which can be assembled in a variety of ways to meet different performance requirements. Furthermore, heat exchanger cores should have sufficient strength to withstand the extreme conditions to which they can be subjected in vehicular applications, and the like. It is to meet this combination of requirements which the heat exchanger core and the components therefor embodying this invention are directed.
SUMMARY OF THE INVENTION The teachings of this invention are embodied in a heat exchanger formed by a plurality of nested stacked plate structures, each of which comprises a plate strip having equisized trough-like projections formed therein in equispaced parallel positions transverse to the longitudinal axis of the strip. The bottoms of the projections define a plurality of apertures therein to provide for the reinforcement of the long sidewalls as well as cause agitation in the flow of fluid through the tubes formed by the nested projections. As one aspect of the invention, the walls of the projections are formed with offsets whereby the opened ends of the projections will receive the bottom ends of the projections of adjacent plate structures in spaced relationship therewith.
As another aspect of the invention, a crimp or bend is provided across the plate strips in the portions between adjacent projections to provide for easy stacking of the plate structures. In a further aspect of this invention, the apertures in the bottom of the trough-like projections are asymmetrically located with respect to the longitudinal center of the troughs. Thus, when all of the nested plate structures are aligned in the same direction, the apertures will be in alignment to provide a particular flow pattern, whereas another flow pattern will result when alternate plate structures are aligned in opposite directions.
Other objects, advantages and features of this invention will become apparent upon a further reading of this specification, especially when taken in view of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a tube and fin heat exchanger embodying the teachings of this invention;
FIG. 2 is a partial perspective view of one corner of the upper and lower heat exchanger shrouds;
FIG. 3 is a partial section view of the heat exchanger core taken along the line 3-3 of FIG. 1;
FIG. 4 is a perspective view of one plate structure for forming a heat exchanger core;
FIG. 5 is a partial plan view of a plate structure; and
FIG. 6 is a perspective view of the upper header plate of the heat exchanger. 1
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 1, there is shown a heat exchanger 10 designed for use as an oil cooler for a high performance automobile. It consists of a fin and tube type core matrix 12 with an inlet header assembly 14 in cooperative assembly with the core at its upper end and an outlet header assembly 16 in cooperative assembly with the bottom end of the core 12. The core matrix 12 comprises a plurality of stacked plate structures 18 having trough-like projections 20 (FIG. 3) nesting together, in a manner to be hereinafter discussed, to form a fin and tube type assembly. The upper header includes an upper header plate 22 and an upper header shroud 24, together which form the upper header chamber'26. The upper header plate 22 has a number of elongated apertures 30 therein which are in cooperative relationship with the formed tubes of the core structure so as to permit distribution of the fluid received at the fluid inlet 32. The lower outlet header assembly 16 comprises a lower header plate 34 and a lower header shroud 36, preferably of the identical construction as the upper shroud 24, together which form the lower header chamber 38. The'lower header plate 34 has a number of elongated apertures 40 defined therein, which are in cooperative relationship with the formed tubes of the core to permit passage of the fluid therethrough to the lower header chamber 38 where the fluid is collected and transmitted to the outlet 42.
The upper and lower shrouds 24, 36 are fastened to their respective header plates 22, 34 by means of rolled outer edges 44, 46 which receive the outer edges 48, 50 of the respective header plates 22, 34. The rolled edges on the header plates are preferably formed before assembly with the shrouds 24, 36 and the shrouds then assembled with the headers by sliding the edges 48, 50 into engagement with the rolls 44, 46. To facilitate that type of assembly, whether it is to be a manual or automated function, locator tabs 52, 54 are provided at the end of the header plates 22, 34 which cooperate with or stops apertures 57 to help'locate the longitudinal position of the shrouds with respect to the header plates and maintain them in their relative position. The header plates and shrouds may be sealed together around their edges by any appropriate means such as brazing or welding.
As previously mentioned, the heat exchanger core 12 is made up of a number of stacked plate structures 18, as may be best seen in FIGS. 3, 4 and 5. The plate structures are designed to be simply fabricated from plain metal strips by simple automated machine processes. All of the plates forming a core are identically constructed so that they can be formed from large rolls of plate strip material 55 and cut to the proper size for stacking to form the heat exchanger core. As indicated earlier trough-like projections 20 are formed in the strip material in equispaced parallel positions aligned transverse to the longitudinal axis 56 of the plate strip 55. The walls 58 (FIG. 3) have outwardly spaced offsets 60 therein sothat the bottom portion 62 of each projection will nest within the upper portion of the trough-like projection of the adjacent lower plate structure. The height along the projection walls 58 at which the offset 60 is located determines the spacing between the core plates.
The trough-like projections are regularly spaced along the length of the plate strip 55 but, as is well known, it is impossible to maintain exact dimensions therebetween to enable the easy stacking of the nested plate structures. The plate structures are therefore provided with a slight crimp or bend 66 midway between projections and having an axis transverse to the plate longitudinal axis. Thus when the plate structures 18 are stacked to form the core, there is a certain amount of give ineach plate to overcome dimensional differences between projections.
The bottom wall 68 of each trough-like projection 20 defines a plurality of apertures 70 which are regularly spaced along the length thereof. The apertures 70 are preferably, but not necessarily, round, having a diameprojections between the two extended length sidewalls 58. The bands 72 between the apertures 70 serve a dual purpose in the heat exchanger core. They serve to strengthen the assembly by giving support between the long sides of the trough-like projections, and they also serve as turbulence creators for the fluid flowing through the channels formed by the stacked projections. Applicants have found it advantageous to offset the spacing of the apertures 70 with respect to the longitudinal center of the plate 18 so that the ones on one side of the longitudinal center of the trough will be spaced different amounts from the center than those on the other side. This permits the plate structures 18 to be stacked with alternate plates rotated l80 in lengthwise orientation so that the holes 70 of adjacent structures are not aligned. The repeated change in flow directions as the fluid flow therethrough results in a mixing action which enhances the heat transfer of the core. Alternatively, the plate structures 18 can be assembled with the holes aligned, which might be preferable for some heat exchanger applications.
As can be seen in FIG. 6, the upper header plate 22 has flanges 74 around each of the elongated holes 30 at its bottom surface. These are provided so as to meet with the upper open ends of the trough-like projections 20 in the top plate structure 18 forming the heat exchanger core as shown in H6. 3. The apertures 40 in the lower header plate 34 are sized to receive only the bottom portion 62 of the bottommost plate structure 18 forming the heat exchanger core 12.
The simple manner in which a heat exchanger of the type described may be fabricated and assembled is readily apparent. The plate structures 18 can easily be formed from extended lengths of strip material by well known automated techniques. The plates can then be I automatically assembled, either in the alternate or the aligned manner, since the crimps 66 between the projections 20 allow for dimension diiferentials and the offsets on the projection walls 58 serve to determine the spacing between the plates. The core of stacked plate structures can then be fixed together and sealed by automatic brazing techniques or the like. As an alternative the header plates and header shrouds may be assembled therewith by automated procedures and the whole heat exchanger structure sealed together by well known brazing techniques.
While there has been disclosed a preferred embodiment of this invention, it is to be understood that modifications and additions may be made thereto without deviating from the scope of the invention. It is therefore intended to be bound only by the scope of the appended claims.
What is claimed is:
l. A heat exchanger core comprising a plurality of plates of finite width, a plurality of equal sized troughlike projections integrally formed on each plate and located at equal spaced parallel positions along a respective axis transverse to the longitudinal axis of the respective plate, each of said trough-like projections defined by spaced side walls, spaced end walls and a bottom planar wall spaced from the respective plate to define an open end adjacent the respective plate, the bottom wall of each projection having a plurality of apertures therein to define bands between said apertures for rigidifying said bottom wall, said side walls and end walls of each projection each having an outwardly offset portion adjacent the respective plate to enable the open end of each projection to nestingly receive the bottom wall and a portion of the side and end walls of a respective projection an an adjacent plate, whereby said plates are stacked to form a core with the offset portions determining the spacing between said plates, said bottom wall apertures closely spaced along each bottom wall to provide fluid paths through the projections of each plate with said apertures located asymmetrically with respect to the longitudinal axis of each plate whereby said plates are either stacked with said apertures in aligned positions or alternate plates are rotated and stacked with said apertures in offset positions for forming either a straight or tortuous fluid communication path through the projections of said stacked plates, and a bend fonned in each plate spaced between and from each pair of said projections forflexure about an axis transverse to the respective plate longitudinal axis for controlling the distance between each projection to compensate for dimensional differences in said projections for enabling alignment of the projections of said plates for stacking.
2. In the heat exchanger core claimed in claim 1, a first header plate adjacent one end plate of said stacked plates with said header plate having a plurality of equally spaced ports each defined by a flange projecting from said header plate and corresponding in number, shape and dimension to the open ends of said one end plate projections for enabling each flange to be received in the open end of a respective end plate projection, a second header plate adjacent the opposite end plate of said stacked plates with said second header vplate having equally spaced apertures therein for receiving the bottom wall and a portion of the side and end walls of a respective projection on said opposite end plate, a shroud with a flat peripheral face for each header plate for forming a respective sealed header chamber in conjunction with a respective one of said header plates, a rolled edge on each of said header plates for nestingly receiving a respective edge of the flat face of a respective shroud in response to movement of said shroud along the longitudinal axis of said plates, locator tabs on said header plates for engaging with stops formed on the flat face of the respective shroud to limit said movement to thereby locate said shrouds relative said header plates, means for providing fluid flow into one of said chambers defined by said one header plate and the respective shroud, and means for providing for the flow of fluid out of the other of said 5 chambers defined by said other header plate and the respective shroud.