Patent Application
20080216987
Priority is hereby claimed to German Patent Application No. DE 10 2007 011 762.2, filed Mar. 10, 2007, the entire contents of which is incorporated herein by reference.
The invention relates to a heat exchanger, such as an oil cooler, having a connecting plate.
DE 103 49 141 A1 discloses a plate heat exchanger constructed from trough-shaped heat exchanger plates which are stacked into one another. This type of heat exchanger is used in a vehicle as an oil cooler. The publication proposes a solution which can withstand internal pressures of 6 to 10 bar. This is obtained by using an intermediate plate as a tie rod which is inserted and soldered in between the closure plate and the final, uppermost turbulence insert. The intermediate plate has the same hole pattern as the turbulence insert which is soldered to it. The structural principle proposed there has the disadvantage that, at yet higher internal pressures, defects can occur, since the turbulence plates are usually produced from metal sheets of very low wall thickness which are restricted in terms of their resistance to extreme internal pressures. The known closure plate has convexities in the region of the collecting ducts, which convexities are aligned substantially inward.
It is the object of the invention to further improve the resistance of the heat exchanger to internal pressure. The object is achieved according to the invention with the generic heat exchanger by means of its refinement as explained in greater detail below.
Because the intermediate plate is arranged between the closure plate and the uppermost heat exchanger plate, and because at least one of the holes therein interacts, as a pressure equalizing opening, with the upwardly aligned convexity in the closure plate, the heat exchanger is now also suitable for internal pressures of considerably higher than 10 bar. The pressure equalizing opening makes it possible, for example, for the oil to enter into the space between the convexity and the intermediate plate and to impart a force there which counteracts the force which acts between the heat exchanger plate and the intermediate plate. A certain pressure release is thereby obtained.
A pressure release is also obtained in that the closure plate is replaced by a closure disk which has the convexity and which is connected to the intermediate plate, with the diameter of the convexity being greater than the diameter of the collecting duct, with the intermediate plate being arranged on the uppermost heat exchanger plate. The alternative proposed solution therefore dispenses entirely with the closure plate and uses merely a closure disc which is slightly larger than the duct which it closes off. The size of the diameter of the pressure equalizing opening D is in the range from 1 mm to 10 mm, preferably in the range from 1 mm to 2 mm.
The closure plate and the intermediate plate can have different thicknesses a and z. The values are in the range of 1 mm to 3 mm for the thickness a and in the range from 1 mm to 2 mm for the thickness z.
The convexities in the closure plate have a greater diameter than the collecting ducts of the media.
An alternative or additional possibility for increasing the internal pressure stability is to design the penultimate turbulence plate, which is situated in the flow duct of the one medium, in such a way that it does not have an opening like the other turbulence plates. A preferably small hole which has the function as a pressure equalizing opening can however be provided in the turbulence plate in the region of the collecting tank.
The lowermost heat exchanger plate is formed from a thicker metal sheet than the other heat exchanger plates. The fastening plate is also of at least two-part design.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
The invention is now briefly described in various exemplary embodiments with reference to the appended drawings.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
The basic design of the heat exchanger is described with respect to
Circular openings 21, 31 are provided in the heat exchanger plates 10. The openings 21, 31 are provided with projecting edges 101, 102. The projecting edges 101, 102 bear against one another and thereby define the collecting ducts 20 and 30 for the two media, which collecting ducts 20 and 30 are hydraulically connected to the associated flow ducts 8 and 9. Turbulence inserts 5 are arranged in the flow ducts 8, 9 between two heat exchanger plates 10. Other turbulence-generating means, such as for example knobs, beads or the like, could also be inserted into the flow ducts 8 and 9, which are not shown here. The lowermost heat exchanger plate 13 is produced from a thicker metal sheet of approximately 2 to 5 mm thickness. In this manner, the heat exchanger 1 is more stable at high internal pressures and occurring vibrations.
The two exemplary embodiments show a fastening plate 14(a+b) which is of two-part design but can also be of single-part or three-part design. Inlet and outlet openings 25, 35 for the two media are situated in said fastening plate 14, which media are in this case conducted into and out of the heat exchanger 1 through the fastening plate 14. The connecting pipes for the two media can alternatively or also be formed on the upper closure plate 12 (not shown). The edge of the closure plate 12 is ideally soldered to the edge 100 of the uppermost heat exchanger plate 10. For this purpose, the edge 100 can be formed by bending or by means of chamfering/beveling, so that the edge 100 is approximately form-fitting with respect to the edge 100 of the uppermost heat exchanger 10.
Situated in the intermediate plate 11 above the collecting ducts 30 of one medium is another hole 2 whose diameter D is less than or equal to the diameter d of the collecting ducts 30. The diameter D is ideally in the range from 1 to 10 mm, though a very small hole 2 which does not close up during soldering is sufficient. The stresses which act are conducted outward via the intermediate plate 11 into the region outside the collecting ducts 30. The uppermost turbulence insert 5 in particular is protected. This is because, at high internal pressures in the range of 10 to 15 bar or more, the uppermost turbulence insert 5 would, without the intermediate plate 11, be torn open by the occurring stresses. In addition, the shape of the convexities 6 in the closure plate 12 ensures that the occurring forces are conducted outwardly more effectively. The diameter AP of the convexity 6 is therefore greater than the diameter d of the collecting ducts 30.
Various features and advantages of the invention are set forth in the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2007 011 762.2 | Mar 2007 | DE | national |
