EP0903555A2 - Fin for heat exchanger and method for making holes in such a fin - Google Patents

Abstract

Fins (1) form part of a fin/tube block which when assembled has passages (3) for tubes. Each passage has at least one support edge (6) at least partly encircling it, bent at right angles to the passage axis. Preferably the support edge is provided with at least one coplanar, ear-shaped lug, projecting outwards. Independent claims are also included for the method of manufacturing fin passages by forming a cut in a sheet which is then deformed.

Description

The invention relates to a fin for a heat exchanger, the one made of tubes and across these ribs composite ribs / tube block, with several Pull-throughs in the assembled state of the fins / tube block pick up the tubes with each thread spacer for a uniform, corresponding to the rib division Positioning to the respective adjacent rib, as well as a method for producing rib passages in such ribs, whereby from a flat rib plate Forming a collar forming the passage is issued becomes.

Such a rib and such a method are from DE 44 04 837 A1 known. To ensure an even rib division for the fins of a fins / tube block of a heat exchanger the tubes of the fins / tube block Passages of the ribs with spacers in the form of pronounced noses distributed over the circumference of the passages. To produce the passages of the ribs are in a first method step from a correspondingly level Rib plate in the area of each passage punched out, rags being cut free at the same time, in the in a subsequent process step as Spacer serving noses are impressed. Subsequently the lobes including those embossed outwards Noses drawn in and tipped using stamp and die and finally the entire collar including the rag and noses pulled through completely. When punching the Through openings a punching waste arises, which by means of separate Operations must be removed to prevent that it contaminates the tool. Such additional Working processes are especially the blowing out of the punching waste with the help of compressed air nozzles.

The object of the invention is a rib of the aforementioned Art to create that with simplified manufacturability at least equally good spacer functions for achieving an even rib division like the state of the Technology enables. The object of the invention is furthermore to create a process of the type mentioned that one reduced manufacturing effort to create the ribs guaranteed.

For the rib, the task is solved in that everyone Threading with at least one perpendicular to a threading axis angled outwards and at least partially circumferential support edge is provided, which is a flat contact surface for the adjacent rib. According to the invention the respective passage for both round and flat oval or be designed for flat pipes. Through the support edge will further improve the support above Rib lying, adjacent rib created so that a reliable adherence to the uniform rib division of the ribs / pipe block is achievable. For flat or flat oval Pipes each passage preferably has two on opposite Support edges arranged on the long sides of the passage on, which correspondingly turned outwards are. The flat contact surface formed by the support edges runs parallel to the rib plane. By providing the least an additional support edge is possible at the production of the passages on the punching of passage openings - as is the case with the prior art - too do without and the passages on the basis of simple separating cuts to manufacture.

In an embodiment of the invention, the at least one support edge is with at least one ear-like protruding coplanar to the outside Provide tab. The ear-like tab enlarged the flat contact surface for the adjacent rib, see above that a further improved block assembly of the fins / tube block is achievable.

For the method, the task is solved in that first at least one cut in the flat ripper plate is introduced, and that subsequently through the separating cut formed cut edges are formed into the collar. In contrast to the prior art, the invention Process no waste as there is no punching Creation of through openings is needed. The passages are rather created on the basis of simple separating cuts. Since there is no punching waste, the necessary ones are eliminated Operations for the removal and disposal of the Punching waste. This makes the production of the Ribs can be achieved. The pressing tools can also be simplified be produced as no measures are taken be a removal of the punching waste from the Achieve punching areas.

In an embodiment of the invention, the separating cut is made on his opposite ends forming ear-like Straps curved. The curved course of the separating cuts ensuring the formation of the ear-like tabs that no tearing in the subsequent forming stages the ribbed plate is made at the level of the separating cut. Consequently an improved producibility of the rib passages is achieved.

Fig. 1

zeigt in einer Draufsicht auf einen Teil einer Ausführungsform einer erfindungsgemäßen Rippe einen Rippen/Rohrblock eines Wärmeübertragers,

Fig. 2a

ein ebenes Rippenblech im Bereich eines Trennschnittes zur Herstellung eines Durchzuges für die Rippe nach Fig. 1,

Fig. 2b

einen weiteren, an den Herstellungsschritt nach Fig. 2a anschließenden Herstellungsschritt zur Schaffung des Durchzuges,

Fig. 3a und 3b

Schnittdarstellungen entlang der Schnittlinie III-III in den Fig. 2a und 2b des Rippenbleches in den Herstellungsschritten nach den Fig. 2a und 2b,

Fig. 4a

einen weiteren Herstellungsschritt zur Erzielung des Durchzuges in der Rippe nach Fig. 1,

Fig. 4b

den fertiggestellten Durchzug der Rippe nach Fig. 1,

Fig. 5a

eine Schnittdarstellung des Umformvorganges für den Herstellungsschritt nach Fig. 4a entlang der Schnittlinie V-V in den Fig. 4a und 4b,

Fig. 5b

eine Schnittdarstellung entlang der Schnittlinie V-V in den Fig. 4a und 4b des letzten Herstellungsschrittes zur Erzielung des Durchzuges für die Rippe nach Fig. 1,

Fig. 6 bis 10

verschiedene Herstellungsschritte zur Herstellung einer Rippe ähnlich Fig. 1, bei der Stützränder der Durchzüge mit ohrenartigen Laschen versehen sind.

Further advantages and features of the invention result from the following description of preferred exemplary embodiments of the invention, which are illustrated with the aid of the drawings.

Fig. 1

shows a top view of part of an embodiment of a fin according to the invention a fin / tube block of a heat exchanger,

Fig. 2a

a flat rib plate in the region of a separating cut for producing a passage for the rib according to FIG. 1,

Fig. 2b

a further, subsequent to the manufacturing step of FIG. 2a manufacturing step to create the swipe,

3a and 3b

Sectional views along section line III-III in FIGS. 2a and 2b of the ribbed plate in the manufacturing steps according to FIGS. 2a and 2b,

Fig. 4a

a further manufacturing step to achieve the passage in the rib of FIG. 1,

Fig. 4b

the completed passage of the rib of FIG. 1,

Fig. 5a

4a along the section line VV in FIGS. 4a and 4b,

Fig. 5b

4a and 4b of the last manufacturing step to achieve the passage for the rib according to FIG. 1,

6 to 10

different manufacturing steps for producing a rib similar to Fig. 1, are provided in the support edges of the passages with ear-like tabs.

Ribs 1, 1a, as cut out in FIGS. 1 and 10 are part of a fin / tube block for one Heat exchanger, especially for use in one Motor vehicle, a variety of parallel to each other aligned ribs 1, 1a each with a variety of Provided parallel passages 3, 3a are a multitude of in a row in parallel side by side Take running pipes. The tubes are shown Embodiment designed as flat oval tubes, the passages 3, 3a are correspondingly identical are designed. The one composed of fins 1, 1a and tubes Ribs / tube block becomes mechanical in a manner known per se added, the passages 3, 3a of the superimposed Ribs 1, 1a tightly enclose a tube. The passages 1, 1a of the ribs 3, 3a each protrude rectified from the associated rib and form for the overlying rib 1, 1a spacer, so that a uniform rib division of the ribs / tube block achieved becomes. The basic structure of a fin / tube block, such as it has been previously described, including mechanical Joining of the fins / tube block is detailed in DE 44 04 837 A1 described and disclosed by drawings, see above that referred to this document for a more detailed explanation becomes.

According to FIGS. 1, 4b and 5b, the rib 1 has a flat rib plate 2, whose longitudinal edges each with one Edge groove 5 are provided. Along the flat rib plate 2 are aligned parallel to each other at regular intervals Passages 3 provided, the passage opening to the The outer contour of flat oval tubes is adapted. Between neighboring passages 3 are known gill fields 4 provided, for their further explanation also on the DE 44 04 837 A1 is referred. The passages 3 are identical designed to each other. Each passage 3 has a circumferential, perpendicular to the one that defines the rib plane Rib plate 2 on one side of the collar 9, on in the area of the opposite long sides of the collar 9 Connect two supporting edges 6 that are set out at right angles to the outside. The surface of the support edges 6 runs parallel to the rib plane formed by the rib plate 2. in the Transitional area between the collar 9 and the support edges 6 are on both long sides of the collar 9 three in uniform Intervals arranged lugs 7 stamped. The Noses 7 are analogous to those described in DE 44 04 837 A1 Noses so pyramid-shaped that they are in the Level of the support edges 6 has a triangular cross section form. The lugs 7 are on the opposite long sides each thread 3 is mirror-symmetrical to a central longitudinal plane each passage 3 arranged so that each long side the passage 3 and thus each supporting edge 6 each three lugs 7 are assigned. The lugs 7 have one Spacer function, which for itself from DE 44 04 837 A1 is already known, a stiffening function for the two support edges 6 on since they are a for the support edges 6 Form web-like support function.

As can be seen from Fig. 5b, the upper edges of the Lugs 7 in common alignment with the support edges 6, so that through the top edges of the lugs 7 and through the Support edges 6 formed support surface parallel to the rib plate 2 are aligned and the support surface for the assembled Condition above and identical designed rib 1 form.

The rib 1a according to FIG. 10 essentially corresponds to the rib 1, as previously described. Same parts of the Rib 1a are therefore with the same reference numerals, only designated with the addition of the letter a. Only one Difference in the rib 1a to the rib 1 according to FIG. 1 it is that the passages 3a of the rib 1a on diagonally opposite End areas of the opposite support edges 6a each have an ear-like tab 10 which is coplanar protrudes to the support edge 6a to the outside. The ear-like tab 10 has manufacturing reasons, as described below will be.

First, however, the manufacturing process for passages 3 of the rib 1 will be described. To produce passages 3 within the fin 1, a separating cut 8 (FIGS. 2a and 3a) is made in the fin plate 2 at the level of the respective pipe pitch and thus the later positioning of the passages 3 transversely to the longitudinal axis of the fin plate 2, which is made by a suitable cutting tool with simultaneous support of the rib plate 2 is achieved. In a further method step, the support edges 6 and the lugs 7 are created according to FIGS. 2b and 3b. For this purpose, a stamping die S ₁ , which acts at right angles to the ribbed plate and which interacts with a die (not shown _{), is} provided as a corresponding forming tool. The die S ₁ has a blade-like shape with a cross section that corresponds to the course of the support edges 6 in FIG. 2b. The embossing die S ₁ also has embossed edges of this type on the side in such a way that the lugs 7 are embossed by the shaping step together with the angling of the supporting edges 6. After the method step according to FIGS. 2b and 3b, the support edges 6 protrude upward at right angles to the rib plane formed by the rib plate 2. According to FIG. 3b, the bottom of each nose 7, which is triangular in cross section, extends inward and upward at an acute angle to an underside of the ribbed plate 2 to the respective supporting edge 6. The cut edges formed by the separating cut 8 are thus flared up and expanded to form the support edges 6. The widening must be carried out carefully so that the separating cut 8 does not tear at the opposite end regions.

In a further method step, a further widening of the passage opening, whereby increased by a further, opposite the stamper S ₁ in the width stamper S _2, a peripheral, in this process step or obliquely upward is Upset and thus created conically upwardly tapered collar 9 . For this purpose, the die S _{2 is provided} with a correspondingly elliptical and tapered embossing contour. The embossing die S ₂ is used for reshaping such that additional material of the rib plate 2 is pressed obliquely upward in the area of the passage opening, which results in the circumferential collar 9 below the lugs 7 and the support edges 6. In this intermediate stage, the collar 9 tapers upwards towards the free end of the passage opening and the two supporting edges 6 protrude at an angle upwards and outwards at right angles to the collar. In a further process step, the end contour of the passage 3 is achieved by means of a stamping die S ₃ which is widened in cross section, the collar 9 being pulled through in such a way that its circumferential wall is turned upwards at right angles to the rib plane. This process step, documented with reference to FIGS. 4b and 5b, comprises the finished passage, the supporting edges 6 projecting outward at right angles to the collar 9.

The process for producing the passages 3a from the ribbed sheet 2a corresponds to the rib 1a according to FIGS. 6 to 10 essentially the manufacturing process described above, so that only the differences to the already described manufacturing process is discussed. In both manufacturing processes, the Passages 3, 3a the further completion of the ribs 1, 1a achieved by the gill panels 4, 4a and the edge grooves 5, 5a are impressed accordingly.

The only difference in the manufacture of the passages 3a Rib 1a is that in the first process step a different designed separating cut 8a is made. This separation cut 8a points in addition to its rectilinear middle Area two forehead areas, in which the separating cut below Forming ear-like tabs 10 hook-like curved in the plane of the rib plate 2a runs. Despite the two Curvatures in the area of the opposite forehead areas the separating cut 8a is made in one piece and continuously, wherein the separating cut 8a by means of a correspondingly designed Cutting tool created in a single cutting process becomes. The subsequent embossing cuts correspond those shown with reference to FIGS. 2b, 3b, 4a, 5a and 4b, 5b Process steps for the production of the passage 3, wherein the ear-like tabs 10 are each assigned a supporting edge 6a are and coplanar to this outwardly protruding extend. Due to the hook-like curvature of the cut 8a in its opposite forehead areas there is tearing the ribbed sheet 2a by corresponding notch effects, as in the embodiment of FIGS. 1 to 5b could occur avoided because the ear-like tabs 10th in the embossing of the embossing steps according to FIGS. 7 and 8 emerging stress areas no notch effects in the main load directions arise. In the finished Form the state of the passages 3a according to FIGS. 8 to 10 the tops of the ear-like tabs 10 additional Support surfaces that have a further improved edition of the overlying Allow rib.

In a further embodiment according to the invention several separating cuts for the creation of the subsequently provided through cutting edges that are mutually such are positioned so that there is no cut waste.

Claims (7)

Rib for a heat exchanger which has a rib / tube block composed of tubes and ribs running transversely to these ribs, with a plurality of passages which receive the tubes in the assembled state of the ribs / tube block, each passage providing spacers for uniform positioning corresponding to the rib division of the adjacent rib,
characterized,
that each passage (3, 3a) is provided with at least one support edge (6, 6a) which is angled outward at right angles to a passage axis and at least partially non-running, which forms a flat contact surface for the adjacent rib (1, 1a). Rib according to claim 1, characterized in that the at least one support edge (6a) with at least one coplanar outwardly projecting, ear-like tab (10) is provided. A process for the production of fins in fins for heat exchangers according to the preamble of claim 1 or according to claim 1, wherein a collar forming the passage is issued from a flat finned sheet,
characterized,
that at least one separating cut (8, 8a) is first made in the flat rib plate (2, 2a), and that the cut edges formed by the separating cut (8, 8a) are then provided with the lugs (7, 7a) and to the collar ( 9, 9a) are formed. A method according to claim 3, characterized in that the cut edges with lugs (7, 7a) are provided. A method according to claim 3 or 4, characterized in that the separating cut (8, 8a) at its opposite Ends curved to form ear-like tabs (10) is designed. Method according to one of claims 3 to 5, characterized in that that simultaneously with the embossing of the noses (7, 7a) an expansion of the cut edges to form at least a supporting edge (6, 6a), and that by a further deformation of the collar (9, 9a) - seen in the direction of deformation - Behind the support edge (6, 6a) is formed, the Support edge (6, 6a) to the collar (9, 9a) aligned at right angles is. A method according to claim 6, characterized in that the collar (9, 9a) in two successive steps is completed, taking the first step an inclination of the collar (9, 9a) relative to the rib plate (2, 2a) and in the second step the bend to the End position at right angles from the ribbed plate (2, 2a) respectively.

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