Abstract:
The invention relates to a plate heat exchanger for a motor vehicle, comprising conducting devices ( 3, 4 ) in the form of elongate disks which are stacked on top of each other and soldered together. The disks are composed of two elongate half disks ( 41 ) that form a hollow space for conducting a medium therethrough. Each end of each half disk ( 41 ) is provided with a first through-hole ( 48; 49 ) for feeding or discharging the medium, each through-hole ( 48; 49 ) being disposed between two other through-holes ( 55, 56; 60, 61 ). In order to create a plate heat exchanger that has a simple design and can be produced at a low cost, an edge region ( 57, 58; 62, 63 ) of the other through-holes ( 55, 56; 60, 61 ) is embodied in a raised manner and is substantially provided with the shape of a pot encompassing a bottom in which the associated through-hole is recessed.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS  
       [0001]     This application is a National Stage filing of International Application PCT/EP2006/000166, filed Jan. 11, 2006, claiming priority to German Application No. 10 2005 002 063.1, filed Jan. 14, 2005, entitled “PLATE HEAT EXCHANGER”. The subject application claims priority to PCT/EP2006/000166 and to German Application No. 10 2005 002 063.1 and both references are expressly incorporated by reference herein, in their entirety.  
       BACKGROUND OF THE INVENTION  
       [0002]     The invention relates to a stacked plate heat exchanger, especially for a motor vehicle, with several conduit devices, especially flat pipes, stacked one on top of the other and connected to each other, especially brazed, in the form of elongated plates that are assembled from two elongated plate halves forming a hollow space for passage of the medium and each having at their ends a first through hole for supplying or discharging the medium, wherein this through hole, viewed in the transverse direction of the plate halves, is arranged between two additional through holes.  
         [0003]     A plate heat exchanger is known from European Patent No. EP 0 470 200 B1 which in the finished state has a number of channels connected in series via manifolds and used for a cooling fluid. Each individual channel is composed of a pair of rounded rectangular plates, which are equipped with projecting and outwardly flanged channels and are turned towards each other. The rectangular plates are equipped with bores that are arranged on the short sides and form the manifolds. Spacers that form slotted direct-connection openings for a coolant are arranged between pairs of plates. In addition, a separator is provided between each pair of plates in the area of a corresponding short side. The spacers and the separators are arranged in the same area so that said plates and spacers are connected to each other through a furnace brazing process into a solid body on each short side of the heat exchanger. After the furnace brazing process, at least one channel is produced in the mentioned area that passes through the plates and through the spacers/separators and is provided to be used in connection with installation of the heat exchanger/cooler. The plates and the spacers/separators are provided with two through holes that are symmetrically arranged relative to the openings and recesses, so that during the production process four pipes, having an outer diameter that allows a sliding fit in the so-called bores, are stationarily arranged such that the plates and the spacers/separators on the pipes can be suspended in a desired sequence. When a given number of plates and spacers/separates is stacked, the ends of the pipes are stood upright in order to guarantee that the stacked plates and the spacers/separators are held reliably, after which the furnace brazing process is performed. The known plate heat exchanger comprises many individual parts and has a complicated construction. In addition, the production of the known plate heat exchanger is relatively complicated.  
         [0004]     The task of the invention is to create a stacked plate heat exchanger, which is also designated as a plate heat exchanger, especially for a motor vehicle, with several conduit devices, especially flat pipes, stacked one on top of the other and connected to each other, especially brazed, in the form of elongated plates that are assembled from two elongated plate halves forming a hollow space for passage of the medium and each having at their ends a first through hole for supplying and discharging the medium, wherein this through hole, viewed in the transverse direction of the plate halves, is arranged between two additional through holes; and which is constructed simply and can be produced economically.  
         [0005]     The task is achieved for a stacked plate heat exchanger, especially for a motor vehicle, with several conduit devices, especially flat pipes, stacked one on top of the other and connected to each other, especially brazed, in the form of elongated plates that are assembled from two elongated plate halves forming a hollow space for passage of the medium and having at each of their ends a first through hole for supplying and discharging the medium, wherein this hole, viewed in the transverse direction of the plate halves, is arranged between two additional through holes such that the edge area of the additional through holes is formed raised and has essentially the shape of a pot with a base in which the associated through hole is opened. The raised edge areas of the additional through holes take over the function of the separators of the known stacked plate heat exchanger. The separators can thus be eliminated.  
         [0006]     A preferred embodiment of the stacked heat exchanger is characterized in that the edge area of the first through hole is raised and has essentially the shape of a pot with a base in which the associated through hole is opened. The raised edge region of the first through hole takes over the function of the spacer of the known stacked plate heat exchanger. The spacer can thus be eliminated.  
         [0007]     Another preferred embodiment of the stacked plate heat exchanger is characterized in that a bead is formed between the raised edge areas of the additional through holes and the raised edge area of the first through hole. The bead improves the solderability of a plate pair. In addition, the strength of a plate half is increased by the bead. Preferably, the bead is constructed with a slight spacing, so that both sides of a plate half are connected to the respective adjacent plate half by the bead. Therefore, strong ties are formed in the brazed stacked plate heat exchanger.  
         [0008]     Another preferred embodiment of the stacked plate heat exchanger is characterized in that the beads are connected to each other by a meander-shaped impression or lock-bead, which is formed towards the end of the appropriate plate half between the two additional through holes outside of the first through hole. The meander-shaped impression or lock-bead can also be designated as a bead and reinforces the previously described effect of the bead.  
         [0009]     Another preferred embodiment of the stacked plate heat exchanger is characterized in that the conduit devices are stacked between a base plate and a cover plate. The cover plate and the base plate delimit the stacked plate heat exchanger. One of the plates or both plates can be used to mount the stacked plate heat exchanger, for example, on or in an engine block or filter housing.  
         [0010]     Another preferred embodiment of the stacked plate heat exchanger is characterized in that the base plate has four through holes that are respectively arranged concentrically with the additional through holes in the conduit devices and used for the passage of attachment means whose dimensions are somewhat smaller than the diameter of the additional through holes. The attachment means preferably involve bolts with which the base plate is bolted onto an engine block, for example. The bolts preferably have bolt heads whose outer diameter is greater than the diameter of the through holes in the base plate, but smaller than the diameter of the additional through holes in the conduit devices.  
         [0011]     Another preferred embodiment of the stacked plate heat exchanger is characterized in that the base plate and the cover plate each have four through holes that align with the additional through holes in the conduit devices and are used for the passage of attachment means whose dimensions are somewhat smaller than the diameter of the additional through holes. The attachment means preferably involve bolts with which both the base plate and also the cover plate are bolted, for example, to an engine block with the conduit devices clamped in-between. The bolts preferably have bolt heads whose outer diameters are greater than the diameters of the through holes in the base plate and the cover plate.  
         [0012]     Another preferred embodiment of the stacked plate heat exchanger is characterized in that the conduit devices are each assembled from two equal plate halves rotated relative to each other by 180°, of which each has a plurality of grooves that preferably run in straight lines from one longitudinal side to the opposite longitudinal side of the plate half. The plates, each assembled from two plate halves, are also designated as flat pipes or plates. The stacked plate heat exchanger is therefore also designated as a plate heat exchanger. The straight-line profile of the grooves guarantees unimpaired passage of a medium from one longitudinal side of the plate half to the opposite longitudinal side. The grooves in the hollow space provide good swirling of the medium to be cooled. This provides the advantage that separate turbulence inserts can be eliminated.  
         [0013]     Another preferred embodiment of the stacked plate heat exchanger is characterized in that the grooves are stamped into one side in each plate half. The grooves are formed by straight line, elongated, narrow recesses, which are also designated as beads that are stamped into one side, for example, in a sheet material. Because the grooves are stamped on one side, the production of the plate halves is simplified.  
         [0014]     Another preferred embodiment of the stacked plate heat exchanger is characterized in that the grooves are delimited on the longitudinal sides by a peripheral edge. The peripheral edge is used to connect, especially to solder, two plate halves to each other. The hollow space between the two plate halves is therefore sealed from the surroundings.  
         [0015]     Another preferred embodiment of the stacked plate heat exchanger is characterized in that a plate is formed by two plate halves contacting each other whose grooves are stamped outwards. The grooves delimit the flow path of the medium in the interior of the plate. Preferably there is an inlet at one end of the plate and an outlet at the other end of the plate for the medium.  
         [0016]     Another preferred embodiment of the stacked plate heat exchanger is characterized in that two plates contact each other with their raised areas formed by the grooves and are brazed to each other. Coolant can be led between the raised areas from one longitudinal side to the opposite longitudinal side of the respective plate half.  
         [0017]     Preferably, the grooves run at an angle of 35° to 55°, especially 45°, to the longitudinal axis of the associated plate half. In this way it is guaranteed that the medium can flow from one end to the other end of the plate through the hollow space formed in the interior of the plate. On the other hand, the profile of the grooves according to the invention also guarantees that the medium can flow in two plates from one longitudinal side to the opposite longitudinal side.  
         [0018]     Preferably, the grooves of two plate halves contacting each other are arranged at an angle of 80° to 100°, especially 90°, relative to each other. Therefore, a flow path which has many changes of direction and swirls is created in the interior of the plates for the medium to be cooled. This has the advantage that boundary layers forming in the hollow space during operation are always torn open again. This leads to greatly improved heat transfer in comparison with a smooth channel without grooves. The medium to be cooled is subjected to many changes in direction while flowing through the hollow space. In contrast, the coolant can flow nearly unimpaired and in a straight line through the grooves between two plates contacting each other. The angle of 90° produces a nearly circular solder meniscus at the connecting point of two grooves. In this way, the flow along and transverse to the main direction of flow of the medium to be cooled is affected equally.  
         [0019]     Each of the through holes is, for example, round, elliptical, oval, polygonal, in particular, triangular, quadrangular, polygonal, rectangular or square. The through holes here have in some circumstances a different form and/or size relative to each other.  
         [0020]     Additional advantages, features, and details of the invention emerge from the following description, in which various embodiments are described in detail with reference to the drawing. Here, the features mentioned in the claims and in the description can each be essential to the invention individually or in any combination.  
       BRIEF SUMMARY  
       [0021]     A plate heat exchanger, especially for a motor vehicle, comprising several conducting devices, above all flat pipes, in the form of elongate disks which are stacked on top of each other, are interconnected, particularly soldered together, and are composed of two elongate half disks that form a hollow space for conducting a medium therethrough. Each end of each half disks is provided with a first through-hole for feeding or discharging the medium, each through-hole being disposed between two other through-holes from the perspective of the transversal direction of the half disks. In order to create a plate heat exchanger that has a simple design and can be produced at a low cost, an edge region of the other through-holes is embodied in a raised manner and is substantially provided with the shape of a pot encompassing a bottom in which the associated through-hole is recessed.  
         [0022]     One object of the present disclosure is to describe an improved plate heat exchanger.  
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0023]      FIG. 1  is a front elevational view of a stacked plate heat exchanger according to the invention.  
         [0024]      FIG. 2  is a top plan view of the stacked plate heat exchanger of  FIG. 1 .  
         [0025]      FIG. 3  is a side elevational view of the stacked plate heat exchanger of  FIG. 1 .  
         [0026]      FIG. 4  is the view of a section along line IV-IV in  FIG. 2 .  
         [0027]      FIG. 5  is a section view as in  FIG. 4  according to another embodiment.  
         [0028]      FIG. 6  is a top plan view of a plate half according to the invention.  
         [0029]      FIG. 7  is the view of a section along the line VII-VII in  FIG. 6 .  
     
    
     DETAILED DESCRIPTION  
       [0030]     For the purposes of promoting an understanding of the disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended, such alterations and further modifications in the illustrated device and its use, and such further applications of the principles of the disclosure as illustrated therein being contemplated as would normally occur to one skilled in the art to which the disclosure relates.  
         [0031]     In  FIG. 1 , a stacked plate heat exchanger  1  according to the invention is shown in front view. The stacked plate heat exchanger  1  comprises a plurality of essentially plate-shaped flat pipes  3 ,  4  that are stacked one on top of the other between a base plate  8  and a cover plate  9 . Each of the flat pipes  3 ,  4  has at its ends an opening through which a medium to be cooled, especially motor oil, can be fed or discharged. The medium to be cooled flows through the flat pipes  3 ,  4  in the longitudinal direction. On the outside, the flat pipes  3 ,  4  are impinged on by coolant that flows around the flat pipes  3 ,  4  perpendicular to the plane of the drawing in  FIG. 1 .  
         [0032]      FIG. 2  illustrates the top view of the stacked plate heat exchanger  1  shown in  FIG. 1 . The stacked plate heat exchanger  1  can be fixed by four bolts  11  to  14  to a (not shown) engine block or filter housing or filter housing cover of a motor vehicle. In  FIG. 2  it is indicated that respective through holes  15 ;  16  for the medium to the cooled are provided in the transverse direction in flat pipes  3 ,  4  between a pair of bolts  11 ,  14 ;  12 ,  13 .  
         [0033]     In  FIG. 3 , the stacked plate heat exchanger  1  from  FIGS. 1 and 2  is shown in side view.  
         [0034]      FIG. 4  is the view of a section along line IV-IV in  FIG. 2 . In  FIG. 4 , one sees that the bolts  11 ,  14  each have a bolt head  17 ,  18 , from each of which a stud-bolt  19 ,  20  emerges. The stud-bolts  19 ,  20  extend through through holes  21 ,  22  provided in the base plate  8 . The diameter of the through holes  21 ,  22  is somewhat greater than the outer diameter of the stud-bolts  19 ,  20 . In contrast, the outer diameter of the outer heads  17 ,  18  is somewhat greater than the diameter of the through holes  21 ,  22 .  
         [0035]     In  FIG. 4 , arrows  25 ,  26  indicate that the flat pipes  3 ,  4  have through holes, especially rim holes, whose diameters are somewhat greater than the outer diameters of the screw heads  18 ,  19 . The through holes  25 ,  26  are used for passage of the bolts  11 ,  14  during mounting and for receiving the bolts heads  17 ,  18  in the mounted state of the stacked plate heat exchanger  1 .  
         [0036]     In  FIG. 5 , a section view similar to  FIG. 4  is shown according to another embodiment. A stacked plate heat exchanger  30  can be fixed to a (not shown) engine block of a motor vehicle with the help of four bolts, of which only the bolts  31  and  34  are visible in  FIG. 5 . Bolt  31  has a bolt head  32  from which a stud-bolt  33  emerges. Bolt  34  has a bolt head  35  from which a stud-bolt  36  emerges.  
         [0037]     The flat pipes  3 ,  4  in  FIG. 5  are the same flat pipes as in  FIG. 4 . The flat pipes are also designated as plates, especially as stacked plates, or as disks. The base plate  8  involves the same base plate as in the embodiment shown in  FIG. 4 . In contrast to the embodiment shown in  FIG. 4 , two through holes  38 ,  39  for the stud-bolts  36 ,  33  are provided in the cover plate  9 . The diameter of the through holes  21 ,  22 ;  38 ,  39  in the base plate  8  and in the cover plate  9  are somewhat greater than the outer diameter of the stud-bolts  33 ,  36 . In contrast, the outer diameter of the bolt heads  32 ,  35  is somewhat greater than the diameter of the through holes  21 ,  22 ;  38 ,  39 .  
         [0038]     In the mounted state of the stacked plate heat exchanger  30 , the bolt heads  32 ,  35  contact the cover plate  9  on the outside. The stud-bolts  33 ,  36  extend through the cover plate  9 , the flat pipes  3 ,  4 , and the ground plate  8  into (not shown) attachment holes.  
         [0039]      FIGS. 6 and 7  show a plate half  41  in top view. The plate half  41  has the shape of an elongated plate made from an aluminum sheet with two straight-line longitudinal sides  42  and  43  that are arranged parallel to each other. The plate half  41  is rounded at its ends  44  and  45 . There are through holes  48  and  49  in the ends  44  and  45  of the plate half  41 . The through holes  48 ,  49  each have a raised edge area  50 ,  51 .  
         [0040]     The raised edge areas  50 ,  51  of the through holes  48 ,  49  each have the shape of a pot with a base, in which the through hole  48 ,  49  is removed, as is to be seen especially in  FIG. 7 .  
         [0041]     Viewed in the longitudinal direction of the plate half  41 , a plurality of grooves  52  is stamped between the through holes  48 ,  49 . The grooves  52  preferably run in a straight line from one longitudinal side  42  to the opposite longitudinal side  43  of the plate half  41 . The grooves  52  have the shape of similar recesses, which are raised relative toward same side of the plate half  41  as the edge areas  50 ,  51  of the through holes  48 ,  50 . The ends of the grooves  52  are rounded at the longitudinal sides  42 ,  43 . The grooves  52  are arranged at an angle of 45° to the longitudinal axis of the plate half  41 . Viewed in cross section, the plate half  41  has a wavy profile. The wavy cross-sectional profile is formed by the grooves that are stamped into the plate half  41  on one side.  
         [0042]     For forming a plate or a flat pipe ( 3 ,  4  in FIGS.  1  to  3 ), two essentially identical plate halves  41  are arranged rotated by 180° relative to each other and brazed to each other at their peripheral edges  53 . Here, the edge areas  50 ,  51 , and the grooves  52  are directed outward in order to form on the inside a hollow space for the medium to be cooled. However, the two plate halves  41  are brazed to each other not only at their peripheral edges  53 , but also at the contact points of the grooves  52  and also the raised edge areas  57 ,  58 ,  62 ,  63 . When placing the plate halves  41  one on top of the other, the wavy profiles touch selectively. In the interior of a plate formed by two plate halves  41 , this produces changes in direction again and again for the medium to be cooled flowing through this interior. The plurality of contact points at which the two plate halves  41  are brazed to each other guarantees good pressure stability.  
         [0043]     Viewed in the transverse direction of the longitudinal plate  41 , the through holes  48 ,  49  are each arranged between two through holes  55 ,  56 ;  60 ,  61 . The through holes  55 ,  56 ;  60 ,  61  each have a raised edge area  57 ,  58 ;  62 ,  63  just like the through holes  48 ,  49 . The raised edge areas  57 ,  58 ;  62 ,  63  of the through holes  55 ,  56 ;  60 ,  61  are cup-shaped, as is to be seen especially in  FIG. 7 . The raised edge areas  57 ,  58 ;  62 ,  63  of the through holes  55 ,  56 ;  60 ,  61  are embossed in the same direction. The raised edge areas  50 ,  51  of the through holes  48 ,  49  as well as the grooves  52  are embossed outwardly in the same direction  
         [0044]     Between each through hole  55 ;  56  and the through hole  48  there is a circular arc-shaped bead  65 ;  66 . The beads  65 ,  66  are connected to each other by an essentially meander-shaped impression  68 , which is also designated as a bead. The meander-shaped bead  68  extends between the ends of the circular arc-shaped beads  65  and  66  around the through hole  48 .  
         [0045]     The present invention has been explained using the example of a stacked plate heat exchanger for motor vehicles. However, it is noted that the heat exchanger according to the invention is also suitable for other applications. In addition, modifications in the construction are possible without departing from the invention. In particular, heat exchangers according to the German Patent Application No. 10 2004 012 324.2 are mentioned, which are herewith explicitly incorporated into the contents of the disclosure.  
         [0046]     While the preferred embodiment of the invention has been illustrated and described in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that all changes and modifications that come within the spirit of the invention are desired to be protected.