Abstract:
A tube bottom for a heat exchanger, with a bottom region having slot-type openings, wherein the slot-type openings are rimmed by eyelets and the tube bottom has an attached rim region. Formed between the eyelets and the attached rim region is a U-shaped trough as a receiving region for the foot of a box-like cover. The U-shaped trough has an inner first wall, the attached rim region and a second wall forming the trough bottom, wherein the inner first wall has at least one hump-like raised portion in the continuation of an eyelet on a side oriented toward the U-shaped trough, which bounds the breadth of the U-shaped trough between the attached rim region and the first wall and extends from the trough bottom to that end region of the eyelet oriented toward the U-shaped trough. A depression is formed in the hump-like raised portion.

Description:
[0001]    This nonprovisional application is a continuation of International Application No. PCT/EP2015/065989, which was filed on Jul. 13, 2015, and which claims priority to German Patent Application No. 10 2014 213 758.6, which was filed in Germany on Jul. 15, 2014, and which are both herein incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Field of the Invention 
         [0003]    The invention relates to a tube bottom for a heat exchanger, having a bottom region which has slot-type openings, wherein the slot-type openings are rimmed by eyelets and the tube bottom has an attached rim region, a U-shaped trough being arranged between the eyelets and the attached rim region, the U-shaped trough being formed by an inner first wall, the attached rim region and a second wall forming the trough bottom. The invention also relates to a heat exchanger. 
         [0004]    Description of the Background Art 
         [0005]    Coolant coolers can have a plurality of tubes, which can be traversed by a medium and at the same time can be surrounded by a medium. In a known construction, the tubes are received at their ends in tube bottoms. The tube bottoms have a number of openings corresponding to the number of tubes, one tube each being inserted into an opening. The tube is closed by a box-like cover to form a collecting box. For this purpose, the box-like cover is inserted into the tube bottom and is connected to it. 
         [0006]    A multi-chamber tube is known from DE 199 20 102 B4, which corresponds to U.S. Pat. No. 6,343,645, which is incorporated herein by reference. This multi-chamber tube can be inserted into correspondingly adapted tube bottoms so as to form a heat transfer block. Ribbed elements can be arranged between the multi-chamber tubes, which improve the heat transfer. 
         [0007]    DE 10 2011 085 479 A1, which corresponds to US 2014/0262187, which is incorporated herein by reference, discloses a heat exchanger which has two tube bottoms, in each of which a plurality of tubes is received at their ends. Furthermore, a box-like cover is inserted into the tube bottoms, whereby a heat transfer block which can be flowed through is formed. 
         [0008]    A heat exchanger is known from DE 103 43 239 A1, which corresponds to US 2007/0000657, which is herein incorporated by reference, and which has a heat transfer block having a plurality of tubes received at the ends in tube bottoms. A flow-through heat transfer block is formed by box-like covers, which are inserted into the tube bottoms and are connected to the tube bottoms. 
         [0009]    A bottom plate of a collecting box for a heat exchanger is known from DE 10 2008 011 579 A1. The bottom plate forms the so-called tube bottom, which has a plurality of openings into which tubes can be inserted. A box-like cover can also be inserted into the tube bottom shown, whereby a flow-through heat transfer block can be produced. 
         [0010]    A disadvantage of the devices in the art is, in particular, that the tube bottoms can be adapted only with difficulty to openings of different widths when the width of the tube bottom remains otherwise unchanged. Therefore, an increased adjustment effort is required in order to provide tube bottoms of the same width with openings of different widths. In particular, the receiving area of the tube bottoms, into which the box-like cover is inserted, must be specially adapted to achieve a sufficiently high tightness. For this reason, tube bottoms of different widths are used for openings of different widths, resulting in varying dimensions of the heat exchangers that are formed. This necessitates a higher assembly effort, which adversely affects the assembly time and costs. 
       SUMMARY OF THE INVENTION 
       [0011]    It is therefore an object of the present invention to provide a tube bottom which while maintaining the same width of the tube bottom can be adapted to openings of different widths in the tube bottom. Furthermore, the object of the present invention is to provide a heat exchanger with such a tube bottom. 
         [0012]    An exemplary embodiment of the invention relates to a tube bottom for a heat exchanger, having a bottom region which has slot-type openings, wherein the slot-type openings are rimmed by eyelets and the tube bottom has an attached rim region, a U-shaped trough being arranged for the bottom of a box-like cover between the eyelets and the attached rim region, wherein the U-shaped trough is formed by an inner first wall, the attached rim region and a second wall forming the trough bottom, wherein the inner first wall has at least a hump-like portion in the form of an extension on the side oriented towards the U-shaped trough, which bounds the breadth of the U-shaped trough between the attached rim region and the first wall and which extends from the bottom of the trough to the end region of the eyelet facing the U-shaped trough, which serves to produce a lead-in chamfer for tubes. 
         [0013]    In this case, it is advantageous if a material displacement towards the side of the first wall facing away from the U-shaped trough is formed through the molded-in depression, 
         [0014]    By means of a hump-like portion from the inner wall, the breadth of the U-shaped trough can be particularly advantageously bounded. At the same time, the height of the U-shaped trough on the inside can be defined by the hump-like portion. The hump-like portion can in this case be adapted, in particular, as a function of the respective width of the eyelets. In this way, tube bottoms with an identical basic width can be produced which each have differently wide openings and eyelets. This is advantageous because the same production machines can be used for the different tube bottoms and only the respective thermoforming tools need to be adapted. In addition, a standardized width for the tube bottoms can thus be ensured even in tubes of different widths, whereby the space requirements of the heat exchangers produced can be standardized. 
         [0015]    By means of a formed depression, a targeted material displacement can be achieved. A greater material thickness can be achieved, in particular, on the side of the inner wall oriented away from the U-shaped trough since, in addition, material is displaced there by the molding-in of the depression. This is particularly advantageous to be able to produce sufficiently large-dimensioned lead-in chamfers for mounting the tubes on the tube bottom. 
         [0016]    The transition region between the U-shaped trough and the end region of the eyelet can be individually configured by adapting the hump-like portion, so that sufficient guidance and fixing is provided for the bottom region of a box-like cover, and at the same time, sufficient material thickness for the formation of lead-in chamfers to facilitate tube installation remains. 
         [0017]    The deflection of the hump-like portion can increase from the inner wall outwards from the bottom of the trough towards the respective eyelet. This is advantageous since an oblique surface is produced which faces the U-shaped trough and can serve as a centering aid for the bottom region of a box-like cover. 
         [0018]    The hump-like portion can extend into the bottom region and at least partly surrounds the eyelet. This is particularly advantageous to create higher stability and, at the same time, to achieve softer transitions between the eyelet and the hump-like portion or the inner wall. 
         [0019]    It is also expedient if the first wall has a lead-in chamfer on its side facing away from the U-shaped trough, the lead-in chamfer being arranged on the hump-like portion, and the lead-in chamfer producing a tapering of the slot-type openings rimmed by the eyelets. 
         [0020]    A lead-in chamfer is advantageous for facilitating the insertion of the tubes into the openings rimmed by the eyelets. In this case, it is particularly advantageous if the lead-in chamfers are formed in regions of the tube bottom, which have a sufficient material thickness to form a sufficiently long lead-in chamfer. 
         [0021]    In addition, it is advantageous if the lead-in chamfer is formed on the molded-in depression. A lead-in chamfer on the molded-in depression is advantageous since a material accumulation is produced by the depression, which allows for a lead-in chamfer with sufficiently large dimensions. 
         [0022]    An exemplary embodiment provides that the slot-type openings have two opposing narrow sides and two opposing wide sides, wherein a slot-type opening is tapered by lead-in chamfers on the narrow side and on the end regions of the wide sides facing the narrow side. It is particularly advantageous if lead-in chamfers are formed on both the narrow side and on the wide sides to enable a production that is as exact and simple as possible. In particular, the introduction of the tubes is facilitated in this way. 
         [0023]    Furthermore, the hump-like portion and/or the depression is impressed in the hump-like portion into the tube bottom and/or can be formed by thermoforming. The impressing and/or thermoforming is advantageous to produce the hump-like portion and the depression with the same production methods as are used for the rest of the tube bottom. This simplifies production and thus reduces costs. 
         [0024]    The first wall and the surface of the hump-like portion that are oriented towards the U-shaped trough can be oriented towards the trough bottom at an angle greater than 90 degrees. An angle greater than 90 degrees is advantageous to produce a slope which allows for an advantageous insertion of the bottom region of a box-like cover into the U-shaped trough. 
         [0025]    The side of the hump-like portion facing the U-shaped trough can form a centering aid for the insertion of the box-like cover into the U-shaped trough. 
         [0026]    An embodiment of the invention relates to a heat exchanger with two tube bottoms, wherein the heat exchanger has a plurality of tubes which are arranged parallel to each other and are accommodated at their end in each case in an opening of a tube bottom rimmed by an eyelet, wherein the tubes are inserted along the lead-in chamfers into the respective openings, wherein a box-like lid, which is connected to the respective tube bottom, is inserted into the U-shaped trough of each tube bottom. 
         [0027]    Such a heat exchanger is particularly advantageous since it is particularly easy to install. The lead-in chamfers allow for easy positioning of the tubes in the openings. Furthermore, the centering aid on the hump-like portion allows for simple positioning of the box-like cover in the U-shaped trough. 
         [0028]    Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes, combinations, and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]    The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein: 
           [0030]      FIG. 1  is a sectional view of a tube bottom, 
           [0031]      FIG. 2  is a sectional view of a tube bottom, wherein the transition between the eyelet and the U-shaped trough is formed by a hump-like portion, 
           [0032]      FIG. 3  is a view of two contours each of a U-shaped trough, 
           [0033]      FIG. 4  is a perspective view of a tube bottom, wherein the opening or the eyelet is formed very broad, 
           [0034]      FIG. 5  is a perspective view of an alternatively designed tube bottom, the openings or the eyelets being designed less broadly than in the preceding  FIG. 4 , wherein the hump-like portion has a plateau, 
           [0035]      FIG. 6  is a perspective view of an alternative tube bottom, wherein the plateau is designed flatter than the tube bottom shown in  FIG. 5 , 
           [0036]      FIG. 7  is a sectional view through a tube bottom according to the invention, wherein a depression is formed in the hump-like portion from above, which depression forms a material accumulation on the downwardly directed side of the hump-like portion, 
           [0037]      FIG. 8  is a perspective view of the tube bottom according to  FIG. 7 , 
           [0038]      FIG. 9  is a view of the underside of the tube bottom according to  FIGS. 7 and 8 , 
           [0039]      FIG. 10  is a sectional view through two tube bottoms, wherein one tube bottom with a less broad eyelet is shown, and one tube bottom with a broader eyelet, and 
           [0040]      FIG. 11  is a perspective view of a tube bottom with two different embodiments of a lead-in chamfer. 
       
    
    
     DETAILED DESCRIPTION 
       [0041]      FIG. 1  shows a cross-section through a conventional tube bottom  1 . The tube bottom  1  has a plurality of openings  3  which are arranged on the flat bottom region  2 . The openings  3  are each rimmed by eyelets  4 . Right and left of the openings  3  are U-shaped troughs  5 , which are essentially formed between an attached rim region  6  and an inner wall  7  extending parallel thereto. 
         [0042]    The U-shaped troughs  5  are in each case terminated in the downward direction by the trough bottom  8 . Tubes can be inserted into the openings  3  along the direction  9 . 
         [0043]      FIG. 2  shows a sectional view through an alternatively designed tube bottom  10 , which in particular has a different geometry for the U-shaped trough  14 . Specifically, the transition of the eyelets  13  toward the U-shaped trough  14  is designed differently. 
         [0044]    The tube bottom  10  has a bottom region  11  in which a plurality of openings  12  are formed, which are bordered by collar-like eyelets  13 . The end regions of the eyelets  13  located on the left and right are terminated by hump-like projections  22 , which can be introduced into the inner wall  17  of the tube bottom  10 , for example, by an impressing process. The eyelets  13  project into the U-shaped trough  14  through the hump-like portions  22 . The U-shaped trough  14  is formed by the attached rim region  15 , the inner wall  17  and the trough bottom  24 . The upper region  16  of the attached rim region  15  is further angled as compared to the lower region  15 . 
         [0045]    In particular, the inner wall  17  is at an angle greater than 90° to the trough bottom  24 . The hump-like portion  22 , on its side facing outwards towards the attached rim region  15 , forms a surface  21 , which in particular can be used as a centering aid for inserting a box-like cover or the bottom region of the box-like cover. The surface  21  is inclined such that a box-like cover inserted from above is automatically deflected into the U-shaped trough  14  provided for this purpose. 
         [0046]    The reference numbers  18  and  19  show different possible positions for a bottom region of a box-like cover. The limitation  20  shows the maximum possible inner position for a bottom region. A further displacement of the bottom region inwards would lead to faulty or incorrect mounting. Each arrangement of a bottom region, which is located to the left of the marking  20 , with the aid of the centering aid  21  leads to an exact fit of the bottom region in the U-shaped trough  14 . The tube bottom  10  of  FIG. 2  is likewise already known from the prior art. 
         [0047]      FIG. 3  shows two cross-sections of U-shaped troughs in each case of a tube bottom. A contour of a U-shaped trough with a hump-like shape is shown represented by the reference number  30 , for example, in  FIG. 2 . A contour of a U-shaped trough is represented by reference number  31 , as shown by way of example in  FIG. 1 .  FIG. 3  illustrates the different construction, in particular the different width or the different height on the inner side of the different U-shaped troughs. 
         [0048]      FIG. 4  shows a perspective view of a tube bottom  10  as has already been shown in  FIG. 2 . In  FIG. 4  it can be seen in particular that the hump-like portion  22  has a flat surface  21 , which is directed to the attached rim region  15 , which also serves as a centering aid. The hump-like portion  22  is formed from the otherwise flat inner wall  17 , for example, by thermoforming or impressing. 
         [0049]    The hump-like portion  22  extends not only over the inner wall  17 , but also into the bottom region  11 , where in particular the partial region  23  of the hump-like portion  22  also rims the eyelet  13  along its wide sides. 
         [0050]      FIG. 5  shows an alternative embodiment of a tube bottom  40 . The tube bottom  40  has a bottom region  41 , which has a plurality of openings  42 , which are bordered by collar-like eyelets  43 . 
         [0051]    In the exemplary embodiment shown in  FIG. 5 , the eyelets  43  or the openings  42 , respectively, have a shorter extent in the breadth of the tube bottom  40 . The breadth of the tube bottom  40  is measured here as well as in the other exemplary embodiments in each case from an attached rim region  45  to the rim region situated opposite the latter. 
         [0052]    To compensate for this shortening of the openings  42  or of the eyelets  43  in comparison with the embodiment of  FIG. 4 , the hump-like portion  48  has an extended region which is designed as a plateau  50 . As in the preceding  FIG. 4 , a partial region  49  of the hump-like portion  48  also partially encloses the wide sides of the respective eyelet  43 . The hump-like portion  48  also has a surface facing the attached rim region  45 , which surface can be used as a centering aid. 
         [0053]    The U-shaped trough  44  is formed by the attached rim region  45 , the inner wall  47  and the trough bottom  51 . The attached rim region  45  has slots which can serve for fastening the box-like cover in the tube bottom  40 . The fastening of the box-like cover can be achieved, for example, by clamping, by providing corrugated slot crimping or with the aid of other known fixing elements. 
         [0054]    The hump-like portion  48 , in particular the plateau  50  and the partial region  49 , are likewise formed by an impressing process or by a thermoforming process from the inner wall  47  or the bottom region  41 . 
         [0055]    The plateau  50  serves to bridge between the U-shaped trough  44  and the eyelet  43 . It must preferably be sufficiently flat so that enough material remains on the underside of the tube bottom  40  to be able to form a sufficient lead-in chamfer and at the same time be high enough to provide sufficient height of the U-shaped trough  44  on the inside. The plateau  50  in the exemplary embodiment of  FIG. 5  is designed high. This allows for sufficient height of the U-shaped trough  44  but is not optimal with respect to the lead-in chamfer on the underside. The following  FIG. 6  shows a plateau  70  which is flatter and is thus more advantageous with respect to the formation of a lead-in chamfer, but at the same time requires lower height of the U-shaped trough, which is disadvantageous. 
         [0056]      FIG. 6  shows a further alternative exemplary embodiment of a tube bottom  60 , which has a bottom region  61  with an opening  62  arranged therein and a collar-like eyelet  63 . The opening  62  or the eyelet  63  in  FIG. 6  has a relatively short extent in the width of the tube bottom  60 . For this reason, the hump-like portion  68  likewise has a plateau  70 , wherein the plateau  70  is shorter and flatter than the plateau  50  of the preceding  FIG. 5 . For this purpose, the partial region  69 , which comprises the wide sides of the eyelets  63 , is formed even further from the plane of the bottom region  61  than the plateau  70 . The partial region  69  forms a U-shaped bead which surrounds the eyelet  63  both on the wide sides and on the narrow side. 
         [0057]    The tube bottom  60  also has a U-shaped trough  64 . Like in the preceding figures, the U-shaped trough  64  is formed by an attached rim region  65 , an inner wall  67  situated opposite the latter and a trough bottom  71 . The attached rim region  65  likewise has an outwardly angled partial region  66  in the upper region. The hump-like portion  68  also has a surface directed toward the attached rim region  65 , which surface can be used as a centering aid. 
         [0058]      FIG. 7  shows an embodiment of a tube bottom  80  according to the invention. The tube bottom  80  has a bottom region  81 . Openings  82 , which are rimmed by collar-like eyelets  83 , are formed in the bottom region  81 . The openings  82  have two opposing narrow sides  98  and two opposing wide sides  97 . Correspondingly, the eyelets  83 , which surround the openings  82 , each have two narrow sides  98  and two wide sides  97 . The U-shaped trough  84  is formed by an attached rim region  85  and an inner wall  87  opposing the latter and the trough bottom  94 . 
         [0059]    A hump-like portion  88  is formed from the inner wall  87  and the bottom region  81 , which, in particular with the surface  91  facing the attached rim region  85 , forms a smaller angle with respect to the attached rim region  85  than the inner wall  87 . In addition, the hump-like portion  88  has a depression  90  molded in from above, which is arranged immediately adjacent to the end region of the eyelet  83 . 
         [0060]    Through the depression  90 , which can also be molded into the hump-like portion  88  by an impressing process or by thermoforming, a material displacement downwards takes place which allows for a formation of a lead-in chamfer in particular on the downwardly directed side  96  of the inner wall  87  or of the bottom region  81 . Due to the material displacement, the lead-in chamfer can be made larger overall, wherein in particular, the extent of the lead-in chamfer along the insertion direction of the tube can be enlarged. This simplifies the insertion of the tubes and thus allows for a more stable installation process. The lead-in chamfer is not shown in  FIG. 7 . 
         [0061]    In  FIG. 7 , a partial region  89  of the hump-like portion  88  also rims the wide sides  97  of the eyelet  83 . Furthermore, the hump-like portion provides a sufficient height of the U-shaped trough  84 , whereby a secure positioning of a box-like cover can be ensured. 
         [0062]      FIG. 8  shows a further perspective view of the tube bottom  80 , as has already been shown in  FIG. 7 . In particular, it can be seen in  FIG. 8  that the depression  90  is formed by a rectilinear depression running parallel to the U-shaped trough  84 . Furthermore,  FIG. 8  shows that both the end region  99  of the wide sides  97  and the narrow side  98  of the eyelet  83  or the opening  82  are enclosed by the partial region  89  of the hump-like portion  88 . Moreover, the hump-like portion  88  also forms a flat, inclined surface  91 , which can be used as a centering aid for the bottom region of a box-like cover. 
         [0063]      FIG. 9  shows a view of the tube bottom  80  of  FIGS. 7 and 8 , with a viewing direction from below onto the opening  82  or the eyelet  83 . The side  96  of the inner wall  87  facing away from the U-shaped trough  84  can be seen. In addition,  FIG. 9  particularly shows the lead-in chamfers  92  and  93 , which run both on the narrow side  98  of the eyelet  83  as well as on the end regions  99  of the two wide sides  97 . These lead-in chamfers  92  and  93  are formed, in particular, in the region of the material displacement produced by the depression  90 . In particular, these serve for the simplified positioning and assembly of the tubes in the openings  82 . 
         [0064]    The embodiment according to the invention, as shown in  FIGS. 7 to 9 , can in particular also be combined with the preceding embodiments for less wide eyelets  43  and for wider eyelets  13  of  FIGS. 4 to 6 . In particular, the additional depression  90 , which leads to a material displacement, is advantageous in this case to obtain the required material on the underside of the eyelets  83  to be able to form sufficiently dimensioned lead-in chamfers  92  and  93 . This is due in particular to the fact that the tube bottoms, as shown in  FIGS. 1 to 9 , are preferably produced from a plate-like material by using several thermoforming processes. In each thermoforming process, material compression and material stretching take place, which ultimately lead to a thinning of the base material. By introducing additional depression, this partially disadvantageous thinning can be counteracted and, specifically, material can be displaced to defined regions. 
         [0065]      FIG. 10  shows a comparative view of an embodiment with a tube bottom  80  with a less wide eyelet  83  and a wider eyelet  13  as already shown in  FIG. 4 . In particular, it can be seen in  FIG. 10  that the U-shaped trough  14  or  84  is designed identical, irrespective of the width of the eyelet  13  or  83 . In the case of the less-wide eyelet  83 , the depression  90  is molded into the hump-like portion  88 , as shown in  FIGS. 7 to 9 . In the case of the wider eyelet  13 , this depression is not provided, as already shown in  FIG. 4 . In an alternative embodiment, however, the depression can also be combined with a wide eyelet  13 . 
         [0066]      FIG. 11  shows a comparative view of two lead-in chamfers  101  or  102 , as can be formed as a function of the width of the eyelet, which is designated by the reference number  100 . The lead-in chamfers  101  and  102  in particular form the front-side lead-in chamfers, which are formed on the respective narrow side of the eyelet  100 . Preferably, the lead-in chamfer formed on the narrow side has an angle of approximately 40° with respect to a vertical, while the lead-in chamfers at the end regions of the wide sides preferably have an angle of approximately 30° to the vertical. These values are exemplary and do not particularly limit the design of the individual embodiments. 
         [0067]    The embodiments of the preceding  FIGS. 1 to 11  are exemplary and partially represent embodiments as are known from the prior art. In particular, a combination of the features of the embodiments known from the prior art, which are shown in  FIGS. 1 to 6 , and the features of the embodiments according to the invention, which are shown in  FIGS. 7 to 9 , is possible at any time. The individual embodiments of the figures have no limiting character, in particular with respect to the selection of the material, the arrangement of the individual elements and the dimensioning of the respective elements. 
         [0068]    The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.