METHOD AND APPARATUS FOR MAKING FIN TUBE

Abstract

Method for manufacturing a finned tube, in which a tube base body is finned on its outside, in particular helically, by a band, to which end the band is taken to the tube base body using a guide element and is attached to the base body, in particular by means of a laser beam, characterized in that the guide element is adjusted in particular in respect of its orientation relative to the tube base body during the attachment process.

Claims

1. Method for manufacturing a finned tube (10), in which a tube base body (12) is finned on its outside (16), in particular helically, by a band (13), for which purpose the band (13) is guided toward the tube base body (12) using a guide element (11) and is attached to the base body, in particular by means of a laser beam (21), characterized in that the guide element (11) is adjusted, preferably in respect of its arrangement and/or orientation relative to the tube base body (12), in particular during the attachment process.

2. Method according to claim 1, characterized in that the guide element (11) is adjusted between several, preferably at least three, main feed positions, which each respectively define in particular a different band slope.

3. Method according to one of the preceding claims, characterized in that the guide element (11) comprises a guide roller, in particular such that its axis is displaced in a translatory manner and/or tilted to adjust the guide element.

4. Method according to any one of the preceding claims, characterized in that the guide element (11) is arranged on a robot arm (30).

5. Method according to any one of the preceding claims, characterized in that the next contact of a section of the band leaving the guide element (11) is with the tube base body (12).

6. Method according to any one of the preceding claims, characterized in that the tube base body (12) experiences a change of speed, in particular of axial or rotational speed, during the attachment process.

7. Device for manufacturing a finned tube (10) with a band (13) attached to the outside (16) of a tube base body (12), in particular for performing a method according to any one of the preceding claims, characterized in that the device has a guide element (11) that is adjustable, in particular during the attachment process.

8. Finned tube (10), in particular manufactured according to a method according to any one of claims 1 to 6, comprising a tube base body (12), in particular of copper or aluminum, which is finned on its outside (16), in particular helically, by at least one band (13), characterized in that the finned tube (10) has a varying fin slope.

9. Finned tube (10) according to claim 8, characterized in that the finned tube (10) has several, in particular discrete, areas (25) with a fin slope that is substantially homogeneous, but different from one another, preferably precisely two areas (25a, 25b) or at least three areas (25c, 25d, 25e).

10. Finned tube (10) according to claim 8 or 9, characterized in that the finned tube (10) has a monotonic, in particular strictly monotonic, preferably substantially linear change in fin slope.

Description

[0074] Shown here in the figures:

[0075] FIG. 1 in a highly schematic partial section in a lateral view, a finned tube according to the invention in a straight or as yet unshaped implementation with two areas of different fin slope,

[0076] FIG. 2 a likewise schematic, enlarged section of a finned tube according to the invention showing a single fin,

[0077] FIG. 3 the section according to the circle III in FIG. 2 in an enlarged representation with the addition of another, not yet welded fin to the left of the fin already attached in FIG. 2,

[0078] FIG. 4 in a highly schematic view in perspective, a winding process according to the invention of a band onto a tube base body with the depiction of a guide element formed by way of example as a roller,

[0079] FIG. 5 the arrangement according to FIG. 4 in a view roughly according to view arrow V in FIG. 4 in a highly schematic plan view,

[0080] FIG. 6A a slightly modified embodiment of guide elements, which in particular corresponds to no roller guide, namely in the manner of sliding guides in a highly schematic (sectional) front view,

[0081] FIG. 6B another slightly modified embodiment of guide elements, which in particular corresponds to no roller guide, namely in the manner of a sliding guide in a highly schematic (sectional front view,

[0082] FIG. 7 in a highly schematic lateral view, a guide element arranged on a robot arm during the finning process,

[0083] FIG. 8 in a highly schematic plan view, a basic diagram of a guide element, which is only indicated, in three different main feed positions, and

[0084] FIG. 9 in a lateral view, roughly according to FIG. 1, but truncated and not in partial section, another finned tube according to the invention with three areas of different fin slope.

[0085] It should be stated in advance of the following description of the figures that identical or comparable components are provided if necessary with identical reference signs, in some cases with the addition of small letters or apostrophes. The same also applies to the subsequent claims.

[0086] FIG. 1 shows first an already manufactured finned tube 10 according to the invention, which has basically been produced from two separate pieces. First a tube base body 12 is provided, which is formed as a straight, round tube. Wound helically around the base body 12 is a copper band 13 (alternatively an aluminum band or another band), which is welded onto the tube base body 12. The band 13 thus hereby forms an “endless” structure of fins 13′ (the structure of the fins 13′ naturally actually having a finite, fixed length; the fin structure is formed continuously, in other words).

[0087] As shown in FIG. 1, the band 13 leaves the ends 14 and 15 of the tube base body 12 free and is welded on the surface 16 of the tube base body 12. As is apparent in particular at the left-hand end 15 of the tube base body in the partly transparent depiction, this is formed hollow with a wall thickness d and a diameter D. The fin 13′ here has a fin height h.

[0088] FIG. 1 clarifies here that the finned tube 10 is a finned tube with a varying fin slope. Thus two areas 25a and 25b in particular are provided on the finned tube 10. While area 25b (the larger in the exemplary embodiment) has a relatively high fin slope, the area 25a has a fin slope that is only half as high. In other words, the spacing a between the fins 13′ in area 25b is only half as great as the spacing of the fins 13′ in area 25a.

[0089] An effect of this kind can be achieved in particular in that the axial/feed rate and/or the rotational speed of the tube base body 12 varies during finning. So that the band 13 does not tear in this case, an adjustable guide element 11 in particular is used for this, as will be described later in greater detail. The basic attachment of the band 13 to the base body 12 is now explained in greater detail on the basis of FIGS. 2 and 3.

[0090] Here FIG. 2 shows first in a purely schematic, partial-section depiction the enlarged individual depiction of a cross section 17 of an already welded fin 13′. The fin 13′ is welded to the tube surface 16 in the area depicted.

[0091] The right-hand area of FIG. 3 shows said fin 13′ in an already welded state. The already solidified melt 18 is recognizable here in FIG. 3 in the contact region 19 between tube base body 12 and band 13. The melt 18 consists proportionally of material of both the tube base body 12 and of the band 13 or the fin 13′ (on its underside).

[0092] The fin 13′ is formed roughly rectangular in cross section for this purpose.

[0093] The fin 13′ shown on the right of FIG. 3 is located in finning direction B (as an already fixed section) further forward than a cross section 17′ of another fin likewise depicted in FIG. 3. This cross section 17′ of the other fin and of the band 13 is welded in FIG. 3 precisely in the contact region 19 (which is formed substantially L-shaped on account of the tube surface 16, which is straight in cross section, and the straight lateral edge 20 of the fin).

[0094] To this end a laser beam 21 of a laser, not yet shown in FIG. 3, falls onto the contact region 19. The laser beam 21 here irradiates both material of the band 13 and of the cross section 17′ as well as material of the tube base body 12, in particular on its surface 16.

[0095] Since the cross section 17 of the band 13 is located in the finning direction B ahead of the cross section 17′, the left cross section according to FIG. 3 represents the state of welding of a section of the band 13, so to speak, and the right side according to FIG. 3 then represents the finished, welded state of a section of the band 13. Further sections of the band/fins would naturally follow in particular in finning direction B (and thus already welded) with a defined fin slope.

[0096] FIG. 4 illustrates in a perspective view, which is also schematic, however, the wrapping of the tube base body 12 with the band 13. It is to be gathered from FIG. 4 here that the band 13 runs finally in a straight line, substantially along a feed direction Z, toward the tube base body 12 and then contacts this tangentially on its surface 16.

[0097] Before the band 13 is guided in feed direction Z, however, it runs as shown in FIG. 4 initially along another unwinding direction W. Here it is deflected by a guide element 11 formed as a roller, namely from direction W to direction Z. The guide element 11 according to FIGS. 4 and 5 is thus formed as a guide roller. This guide element 11 is typically a constituent here of a guide device, not otherwise shown, for the band 13.

[0098] The special feature according to the invention now consists in the fact that this guide element 11 is adjustable, in the exemplary embodiment according to FIGS. 4 and 5 along an in particular linear adjustment direction V, for example. This adjustability of the guide element 11 along the adjusting direction V facilitates here in particular an adaptation to the change in displacement speed of the tube base body 12 in axial direction A and/or rotation direction R.

[0099] Let it be noted purely for the sake of completeness that a corresponding guide device actually has more than just one deflection element in practice in order to be able to supply the band from a reservoir or “coil” targetedly to the tube base body 12.

[0100] The tube base body 12 is—although this is not depicted—chucked in order to drive this rotating in rotation direction R and axially in axial direction A. The tube base body 12 can carry the band 13 along during this drive and unwind this, for example from a stock roll (“coil”) or a plate or bed (likewise not shown) in a directed manner and under the influence of a defined tensile and braking force. In addition, a drive can also be provided for the stock roll (for example, a spool drive).

[0101] On account of this tensile force and any feed movement of the band 13 that is present, the band 13 is acted upon continuously and progressively on the surface 16 of the tube base body 12. The impact commences as shown in FIG. 5 approximately from a region identified there by a radial axis 22.

[0102] From this region onward, therefore, the band 13 lies with its underside 23 in contact with the surface 16 of the tube base body 12. In consequence of the rotational movement in rotation direction R, the band 13 then runs in contact with the surface 16 of the tube base body 12 across an angular region f with the tube base body 12 before it is welded to the tube base body 12 in the area of a radial axis designated 24 by a laser beam 21.

[0103] The laser beam 21 is generated by a laser 32, which is depicted only very schematically. This laser 32 can provide a flexible supply here, which enables an ideal approach to the contact region 19 to be irradiated.

[0104] While the inventive guide element 11 according to FIGS. 4 and 5 is a guide element formed in the manner of a guide roller, FIGS. 6A and 6B show alternative configurations 11a and 11b of a guide element according to the invention.

[0105] Thus FIGS. 6A and 6B are intended to illustrate in particular that the guide element itself does not have to have any moving parts at all, for example no guide roller: with this in mind FIG. 6B illustrates that the guide element 11a can be formed as a roughly fork-shaped body 26 in cross section, for example, which provides a motion link 27 for guiding the band 13. The surfaces limiting the motion link 27 can accordingly also be termed guide surfaces 28.

[0106] An alternative configuration is shown in FIG. 6B, in which the guide element 11b is formed substantially closed, the band 13 therefore being guided through an opening 29 (or closed motion link). This closed motion link 29 can also be limited here by corresponding guide surfaces 28.

[0107] Entirely independently of whether the guide element is formed with or without guide rollers, the adjustability of the guide element is crucial for the invention: in all cases according to the invention, the guide element is adjustable (relative to the tube base body), for example pivotable or advantageously movable in a linear or translatory manner.

[0108] Let it be pointed out with this in mind that a guide roller of the guide element 11 does not yet form an adjustable guide element. On the contrary, if a guide roller is present, it is important for adjustability that the guide roller or its axis is adjustable or movable (for example, can experience a parallel movement). In this light, FIG. 4 already indicates a parallel movement or linear movement of the axis of the guide element 11 in the manner of a guide roller. This movement then typically leads (together with a change in speed of the tube base body 12) to a change in the slope of the fins.

[0109] In other words, a change in the (axial and/or rotational) speed of the tube base body 12 to achieve a different fin slope can be supported or cushioned by an adjustment of the guide element, in particular in the sense that any tensions arising due to the change in speed can be relieved.

[0110] FIG. 7 shows a particularly advantageous configuration of the invention. Here a guide element 11 (with or without guide roller), not shown in greater detail, is arranged at the end of a part 29 of a robot arm 30. This robot arm 30 can be a typical robot arm as is known from robotics or robot automation. In particular, articulation points can be provided between the individual parts (29 and 31 in the exemplary embodiment). Additional joints can likewise be provided at the end of the final part 29 also, thus substantially in the region of the guide element 11, for example (not explicitly depicted).

[0111] The arrangement of the guide element 11 on a robot arm makes it possible/easier to produce the finned tubes according to the invention here. In particular, adjustment can take place during finning, namely in the case that a change of speed (rotational or in an axial direction) of the tube base body 12 to be finned takes place to achieve a change in the fin slope, for example. No mount or clamping device for the tube base body 12 is depicted in FIG. 7. Such an apparatus is only indicated by a dashed box.

[0112] The robot arm 30 has other advantages also, namely that in a break in production or similar, for example, the guide element 11 can be moved away from the region 31 before the transition point of the band 13 to the tube base body 12 for servicing purposes, for example (the robot arm 30 can consequently be pivoted for this).

[0113] FIG. 8 then illustrates how the guide element 11 is adjustable purely by way of example between three main feed positions. The guide element 11 shown in continuous lines in the plan view according to FIG. 8 is thus adjustable via an adjustment device, which is not depicted (this does not necessarily have to be a robot arm), in a linear manner in this exemplary embodiment, for example in or opposite to axial direction A, which corresponds to the adjustment direction V.

[0114] Two other main feed positions 11′ and 11″ of the guide element are accordingly indicated by dashed lines in FIG. 8, which illustrate in particular that the band 13 in all three cases depicted meets the tube base body 12 at a slightly different angle (in this case FIG. 8 shows in particular an excessive or exaggerated depiction, however). This other impact angle can ensure in particular here an equalization, relief or approximation of tensions that can arise when changing the band slope during the finning process.

[0115] The angle to be changed is typically not the angle at which the band 13 or the fin 13′ protrudes from the surface 16 of the tube base body 12: this angle β, as shown in FIG. 3, is typically around 90 degrees, to be precise, and is here termed “protrusion angle”. It is typically constant.

[0116] In FIG. 9 this is rather the angle at which the band either deviates in plan view from the axial direction A of the tube base body 12 or (what is designated by angle α in FIG. 9) the angle by which the band or the fin (or its projection) deviates from the orthogonal plane E of the axial direction A.

[0117] FIG. 9 shows here another example of a finned tube 10′ according to the invention, which does not have just two areas 25a and 25b of different slope compared with the finned tube 10 according to FIG. 1, however, but rather three different areas 25c, 25d and 25e.

[0118] FIG. 9 thus illustrates that the finned tube according to the invention can have more than two different fin slopes or more than two different areas with homogeneous fin slope. In the exemplary embodiment according to FIG. 9, the area 25c has a high fin slope, the area 25d has a medium fin slope and the area 25e has the lowest fin slope. The angle α.sub.1 is accordingly greater than the angle α.sub.2 and this in turn is greater than the angle α.sub.3 (α thus identifying the angle of deviation of the fin from the orthogonal plane E to the axial direction A or from the tube circumference).

[0119] The converse would apply in the case of the deviation angle of the fin relative to axial direction A, which angle is not shown (this would be smallest for the area 25e, greatest for the area 25c). Both types of angle are basically suitable, however, for illustrating the change with deviating fin slope.

[0120] The fin slope of the tube 10′ according to FIG. 9 is thus increasing (not strictly) monotonic from left to right.

[0121] What are not illustrated but are likewise within the scope of the invention are also finned tubes that have several areas of the same slope separated from one another (for example, a first area of a first slope, a second area of a second slope and a third area of a first slope again).