EP2064008B1 - Method and blank for producing a screw-tube conveyor and screw-tube conveyor produced in this way - Google Patents

Abstract

The invention relates to a method and a blank for producing a screw-tube conveyor in the form of a cylindrical rotary tube (110) with an internal screw spiral (120) for conveying and mixing a bulk material. To simplify the method and to create even long screw-tube conveyors with small diameters in an relation to their length, it is proposed according to the invention first to produce a one-piece blank, which comprises a base portion in the basic form of a parallelogram and having laterally mounted fins. In a second method step, the fins are then bent, preferably by 90°, with respect to the base portion. In a third method step, the base portion (112) is then bent along bending lines (115i) in such a way that the base portion forms a helical casing portion (111) of the rotary tube (110) and the previously bent-round fins (122) form segments of the screw spiral (120) arranged inside the rotary tube (110). The invention also relates to a screw-tube conveyor produced in this way.

Description

The invention relates to two alternative methods and blanks for producing a screw tube conveyor in the form of a cylindrical rotary tube with internal screw spiral for conveying and mixing a bulk material. Screw tube conveyors are used for the treatment of bulk material, in particular in the pharmaceutical or food industry.

The German patent application 23 52 609 discloses a method of making a finned tube from tape. Thus, the finned tube is made by helically winding a first band, which has the purpose of forming the shell of the tube, joining together the band coils thus caused to adjacent edges. Furthermore, a second band - which has the purpose of forming a rib at least on the inside of the tubular jacket - helically wound on the tube shell wall, preferably within the last finished part of the tubular jacket, and this second band is fastened to the tube shell wall.

Screw tube conveyors are basically known in the art and e.g. defined in DIN 15 201. In addition to the continuous production of the bulk material, screw-tube conveyors always also serve for thorough mixing thereof; In many cases, they can also serve for surface design, for surface coating or for heat treatment of the bulk material. In contrast to so-called screw conveyors, which are not the subject of the invention, screw conveyor for the sole promotion of bulk material are less efficient.

In the traditional production of a screw tube conveyor, a spiral screw is added to the inside of a cylindrical rotary tube, eg welded, soldered etc. by crawling persons, welders, into the screw conveyor and there make the joining work at the transition between the rotary tube and screw helix.

The length of the joining zone between the rotary tube and the screw helix is many times longer than the overall length of the screw tube conveyor. The joining zone is traditionally formed by a very long weld, possibly double-sided, which represents a significant cost factor in the manufacture of the screw conveyor.

In order for such joining work to be possible at all, both the outer diameter and also the inner diameter of the rotary tube must have certain minimum values. The inside diameter of the rotary tube is determined by the height or depth of the screw flights. Also, the screw pitch must not be too small, in order to ensure the accessibility of the joining zone between the rotary tube and screw helix.

Based on this prior art, the present invention seeks to provide a method and a blank for producing a screw tube conveyor, which significantly reduce both the time and cost of manufacturing the screw conveyor during its production.

1. a) Herstellen eines einstückigen Zuschnitts in Form eines grundsätzlich parallelogrammförmigen Basisabschnitts mit mindestens einer seitlichen Lasche, wobei der grundsätzlich parallelogrammförmige Basisabschnitt durch ein erstes und ein zweites Paar von jeweils gegenüberliegenden parallelen Rändern definiert wird, wobei auf dem Basisabschnitt Biegelinien zwischen dem zweiten Paar von Rändern und parallel zu diesen Rändern verlaufend vorgesehen sind und wobei die mindestens eine Lasche an mindestens einem der Ränder des ersten Paares auf Höhe zwischen zwei benachbarten der Biegelinien oder zwischen einem der Ränder des zweiten Paares und einer benachbarten Biegelinie einstückig mit dem Basisabschnitt ausgebildet ist;
2. b) Umknicken der Lasche um einen Laschenknickwinkel γ gegenüber dem Basisabschnitt entlang desjenigen Randes an dem die Lasche einstückig mit dem Basisabschnitt verbunden ist; und
3. c) Knicken des Basisabschnitts entlang der Biegelinien jeweils um einen Mantelknickwinkel δ so, dass der Basisabschnitt einen helix- und polygonförmigen Mantelabschnitt des Drehrohres und die zuvor umgeknickte Lasche am Segment der im Inneres des Drehrohres angeordneten Schneckenwendel bildet.

This object is achieved according to a first embodiment by the method claimed in claim 1. This method is characterized by the following steps:

1. a) producing a one-piece blank in the form of a basically parallelogram-shaped base portion having at least one lateral tab, wherein the basically parallelogram-shaped base portion is defined by a first and a second pair of respective opposite parallel edges, wherein on the base portion bending lines between the second pair of edges and extending parallel to these edges, and wherein the at least one tab is formed integrally with the base portion at at least one of the edges of the first pair at a height between two adjacent ones of the bendlines or between one of the edges of the second pair and an adjacent bendline;
2. b) folding the tab by a lashing angle γ with respect to the base portion along the edge at which the tab is integrally connected to the base portion; and
3. c) buckling of the base portion along the bending lines in each case by a jacket bending angle δ so that the base portion forms a helical and polygonal shell portion of the rotary tube and the previously folded tab on the segment of the arranged inside the rotary tube screw helix.

Due to the claimed integral formation of the blank in the form of the parallelogram-shaped base portion integrally formed thereon tabs, which are later bent over as segments of the screw helix, in the first embodiment, a positive transition between the inside of the rotary tube and the worm helix is ensured, without that, apart would be required by the buckling of the tabs, joining work for establishing the connection between the rotary tube and screw helix inside the screw conveyor. By bending over the tab relative to the base portion, a niche-free transition between the cylindrical rotary tube and the screw helix is formed, so that no bulk material can advantageously settle therebetween.

1. a) Herstellen eines einstückigen Zuschnitts umfassend einen Basisabschnitt in Form eines konvexen Vierecks, vorzugsweise in Form eines Parallelogramms, mit mindestens einer seitlichen Lasche, wobei der grundsätzlich parallelogrammförmige Basisabschnitt durch ein erstes und ein zweites Paar von jeweils gegenüberliegenden grundsätzlich parallelen Rändern definiert wird, wobei auf dem Basisabschnitt Biegelinien zwischen dem zweiten Paar von Rändern und parallel zu diesen Rändern verlaufend vorgesehen sind, und wobei die mindestens eine Lasche an mindestens einem der Ränder des ersten Paares auf Höhe zwischen zwei benachbarten der Biegelinien oder zwischen einem der Ränder des zweiten Paares und einer benachbarten Biegelinie einstückig mit dem Basisabschnitt ausgebildet ist;
2. b) Umknicken der Lasche um einen Laschenknickwinkel γ' gegenüber dem Basisabschnitt entlang desjenigen Randes an dem die Lasche einstückig mit dem Basisabschnitt verbunden ist;
3. c) Knicken des Basisabschnitts entlang der Biegelinien jeweils um einen Mantelknickwinkel δ' so, dass der Basisabschnitt einen helixförmigen Mantelabschnitt des Drehrohres und die zuvor umgeknickte Lasche einen radial nach außen stehenden Kamm auf dem helixförmigen Mantelabschnitt bildet;
4. d) Ineinanderschieben des helixförmigen Mantelabschnitts und einer helixförmigen Schraubenfläche zu dem Schneckenrohrförderer so, dass der Kamm die Schraubenfläche an ihrer Peripherie überlagert und dass ein nicht von dem Kamm abgedeckter Teil der Schraubenfläche die Schneckenwendel im Innern des Schneckenrohrförderers repräsentiert; und
5. e) Zusammenfügen der Schraubenfläche und des Kamms an den überlappenden Bereichen zu dem Schneckenrohrförderer.

The above object is achieved according to a second embodiment by the method claimed in claim 2, which is characterized by the following steps:

1. a) producing a one-piece blank comprising a base portion in the form of a convex quadrilateral, preferably in the form of a parallelogram, with at least one lateral tab, the basically parallelogram-shaped base portion is defined by a first and a second pair of opposing generally parallel edges, wherein the at least one tab on at least one of the edges of the first pair being at a height between two adjacent ones of the bending lines or between one of the edges of the second pair and an adjacent one Bend line is integrally formed with the base portion;
2. b) folding over the tab by a tab angle γ 'relative to the base portion along the edge at which the tab is integrally connected to the base portion;
3. c) buckling of the base portion along the bending lines in each case by a jacket bending angle δ 'so that the base portion forms a helical shell portion of the rotary tube and the previously folded over tab forms a radially outwardly standing comb on the helical shell portion;
4. d) telescoping the helical skirt portion and a helical screw surface to the screw tube conveyor such that the comb overlies the screw surface at its periphery and a portion of the screw surface not covered by the comb represents the screw flight inside the screw tube conveyor; and
5. e) assembling the helical surface and the crest at the overlapping regions to the auger tube conveyor.

The two claimed methods for producing the screw conveyor by folding over the tabs and kinking the base portion advantageously also allow the production of relatively long screw tube with relatively small clear diameters, because, as I said, joining work inside the screw conveyor for connecting the screw spiral with the rotary tube no longer required are.

Because in both methods the screw conveyor is produced over a desired overall length so that individual passages or longitudinal sections are merely joined by spot welding, the danger of distortion is advantageously present in the screw tube conveyors produced in this way - unlike the screw tube conveyors traditionally produced with helical welds much lower.

The screw tube conveyor produced by the two methods claimed comprises a rotary tube with a polygonal cross-section due to the multiple kinked mantle surface. This has the advantage that the mixing of the bulk material when rotating the screw conveyor relative to a rotary tube with a circular cross-section is significantly improved. In particular, this can advantageously be dispensed with by the installation of additional mixing elements, such as wings, paddles, plowshares, etc.

In both embodiments of the claimed method is between each two adjacent tabs on the base portion a V-shaped notch with an opening angle α between 0 ° and 180 ° provided.

Depending on whether a lateral bending angle δ, by which the base section is bent along a bending line, is smaller, equal to or greater than the opening angle a, the following constellations arise in the interior of the rotary tube in the first exemplary embodiment: If the lateral bending angle δ is equal to the opening angle α, so are the two adjacent tabs in the screw conveyor produced by the claimed method "on impact"; there is then no overlap of the two adjacent tabs. When the sheath bending angle δ is smaller than the opening angle α, a V-shaped notch or space remains between the two adjacent tabs. The mentioned gap has the advantage that bulk material can pass through the gap from a passage in an adjacent course of the screw tube conveyor, whereby a better mixing of the bulk material is achieved. If the jacket bending angle δ is greater than the opening angle, the two adjacent tabs overlap after bending along the bending lines.

In the second embodiment, the opening angle α is required to allow buckling of the base portion so that the tabs are radially outward.

The Laschenknickwinkel γ is preferably 90 ° in both embodiments; the screw helix is then aligned in the interior of the screw conveyor perpendicular to the lateral surface of the rotary tube.

Advantageously, the material is punched in both embodiments for cutting to produce the blank, cut with a laser beam or milled.

The above object is further achieved by tailoring the. Producing the screw conveyor solved. The advantages of this blank substantially correspond to the advantages mentioned above with reference to the claimed method

Moreover, it is advantageous that the blank is initially formed flat with the base portion and the at least one tab.

Furthermore, it is advantageous that metal sheets with a thickness of 0.3 to 3 mm can be selected for the blank and thus for the screw conveyor. Such thin sheet metal can not be used for traditionally made screw tube conveyors because it does not allow high temperatures such as occur in long welds. In screw tube conveyors, which are produced according to the inventive method, but it is very useful because long welds are not mandatory; the use of such a thin metal sheet has the advantage that the heat capacity of the screw conveyor is low, and so that the duration of thermal balancing effects between bulk material and auger conveyor can be kept as short as possible when starting treatment processes.

If a plurality of tabs are formed on one and the same edge of the base portion, they may be formed either adjacent or only occasionally in the sense of non-adjacent there. If two tabs are not adjacent, this has the effect that even with the assembled auger tube conveyor between these two tabs a gap remains. This gap then has the same advantageous effect as the above-mentioned V-shaped gap between two adjacent tabs, which then arises when the Mantelknickwinkel is smaller than the opening angle between the two tabs.

So that all adjacent flaps or segments of the screw helix in the interior of the screw conveyor "abut" against each other and thus form a spiral helix without gaps and without overlaps, it is necessary that the opening angle α of the V-shaped notches between each two adjacent tabs and the both limiting angles β ₁ and β ₂ , which are respectively measured between the outer tabs and the perpendicular lines towards the edge of the base section, are dimensioned so that α _i + β ₁ + β ₂ together are 360 ° and that, as already mentioned above, the jacket bending angles δ _{i are formed} corresponding to the opening angles α _i . If said angle sum of α _i + β ₁ + β _{2 is} smaller than 360 ° measured over a length of the base portion corresponding to the circumference of the rotary tube, the adjacent tabs are at least partially overlapped in the assembled screw tube conveyor. In the other case, if the angle sum is greater than 360 °, the said gaps between the adjacent tabs arise.

The formation of the edges opposite the base portion of the trapezoidal lugs in the form of a circular arc has the advantage that in the screw conveyor produced according to the invention a tubular opening in the form of a circular cylinder is formed with a clear radius approximately the radius of the circular arc.

In the method according to the invention, the tabs can be arranged on two opposite edges of the base portion. After the straps have buckled about the respective lashing angle γ and the subsequent buckling of the base section along the bending lines, the helical sections of the screw conveyor (passages) can either be immediately adjacent, depending on the configuration of the parallelogram base section, ie depending on the intended increase for the screw conveyor. ie be touching, or spaced from each other. If the gears of the screw conveyor are in direct contact with each other at a suitable pitch, then the previously folded tabs of the individual gears are at least partially adjacent to one another. It is then recommended that these adjacent eg by a point-welded connection to each other to fold over bent tabs; In this way, the screw conveyor is substantially stabilized. In contrast to the prior art, the spot welding can be done at the edge of the breakthrough, ie at the easily accessible upper edge of the tabs; it does not need to take place at the transition zone, which is much more difficult to access, between the rotary tube and the spiral screw.

In general, the production of screw tube conveyors, even with a large overall length in the two methods according to the invention, is substantially facilitated by the fact that individual (partial) longitudinal sections can be prefabricated and later only have to be joined together. The joining takes place in each case at the edge or connection points of two adjacent (sub) length sections and is particularly simple if the respectively attached longitudinal section in turn is not too long (so that the connection point is accessible from the opposite end of the longitudinal section) and if its diameter or radius is as large as possible.

In principle, the screw conveyor with the method according to the invention can also be produced with a blank in which the tabs are formed only on one of the edges of the parallelogram-shaped base section. The thickness of the helix is then formed only by the thickness of a single tab, but not by the thickness of two adjacent tabs, as in the previous case. In addition, it is then necessary for the helical jacket sections of the rotary tube formed by buckling of the base section to be joined together by a helical weld seam. Although the mantle surface of the rotary tube is then easily accessible, the production of the weld is still costly in this case due to the relatively large length of the weld, which is why this embodiment is only suboptimal.

If it is desired that the rotary tube produced by the method according to the invention is just limited at at least one of its two ends, for example for mounting a flange, then it is necessary for the two opposite edges of the first pair of edges are cut at an acute angle tapering at this end.

Finally, the above object is achieved by a screw tube conveyor. The screw tube conveyor produced by the method and the blank according to the invention has the advantages mentioned above with reference to the method and the blank.

It is advantageous that the screw conveyor can have one or more passages. To achieve a desired greater overall length, it is possible to prefabricate several lengths of the screw tube conveyor with the inventive method and then join these lengths to the screw conveyor in the desired overall length.

It is advantageous if the screw tube conveyor has at least one of its ends a flange, which is preferably attached to the folded tabs in the region of one end of the screw conveyor tube, e.g. is welded. The flange at one end of the screw tube conveyor may e.g. be formed in the form of a gear, which is for engaging the screw conveyor with a, driven by a drive means pinion engageable. At its other, possibly the gear opposite end, a further flange may be provided, which is designed as a raceway. The race is then used for rotatably supporting the screw conveyor on preferably conical rollers. The conical design of the rollers is used to exert an axial pressure on the auger tube conveyor on an existing abutment.

Finally, it is advantageous if the screw tube conveyor coated inside, preferably enamelled, because then with the coating possibly existing narrow gaps or impact gaps between two adjacent tabs of the screw helix can be closed.

Figur 1

einen erfindungsgemäß hergestellten Schneckenrohrförderer;

Figur 2

einen erfindungsgemäßen Zuschnitt zur Herstellung des Schneckenrohrförderers; gemäß einem ersten Ausführungsbeispiel

Figur 3

einen Zuschnitt nach Figur 2 mit umgeknickten Laschen;

Figur 4

einen Zuschnitt mit gemäß dem ersten Ausführungsbeispiel umgeknickten Laschen und mit teilweise geknicktem Basisabschnitt;

Figur 5

einen durch das erfindungsgemäße Knicken der Laschen und des Basisabschnitts hergestellten ersten Gang des Schneckenrohrförderers mit einem Ansatz für einen zweiten Gang, wobei die Laschen im Bereich des Ansatzes des zweiten Ganges und die benachbarten Laschen des ersten Ganges zunächst noch beabstandet zueinander sind;

Figur 6

ein Schneckenrohrförderer nach Figur 5, wobei die Laschen des Ansatzes des zweiten Ganges und die benachbarten Laschen des ersten Ganges durch eine Punktschweißung miteinander verbunden sind;

Figur 7

einen erfindungsgemäß gemäß dem ersten Ausführungsbeispiel hergestellten Schneckenrohrförderer mit Flanschen in Form eines Ritzels und in Form eines Laufringes;

Figur 8

einen Zuschnitt zur Herstellung des Schneckenrohrförderers gemäß seinem zweiten Ausführungsbeispiel;

Figur 9

einen Zuschnitt mit gemäß dem zweiten Ausführungsbeispiel umgeknickten Laschen und mit teilweise umgeknicktem Basisabschnitt;

Figur 10

eine helixförmige Schraubenfläche;

Figur 11

einen gemäß dem zweiten Ausführungsbeispiel zusammengebauten Schneckenrohrförderer; und

Figur 12

einen Schneckenförderer gemäß Figur 11 mit zylinderförmigem Gehäuse

zeigt.The description is a total of 12 figures attached, where

FIG. 1

a screw tube conveyor produced according to the invention;

FIG. 2

a blank according to the invention for the production of the screw tube conveyor; according to a first embodiment

FIG. 3

a cut to FIG. 2 with folded tabs;

FIG. 4

a blank with folded according to the first embodiment straps and partially bent base portion;

FIG. 5

a first course of the screw conveyor with a second gear approach produced by the bending of the flaps and the base section according to the invention, wherein the flaps in the region of the second gear approach and the adjacent links of the first gear are initially still spaced from one another;

FIG. 6

a screw tube conveyor after FIG. 5 wherein the flaps of the second gear approach and the adjacent first gear flanges are connected by spot welding;

FIG. 7

a screw conveyor produced according to the invention according to the first embodiment with flanges in the form of a pinion and in the form of a raceway;

FIG. 8

a blank for producing the screw tube conveyor according to its second embodiment;

FIG. 9

a blank with folded according to the second embodiment tabs and partially folded over base portion;

FIG. 10

a helical screw surface;

FIG. 11

a screw tube conveyor assembled according to the second embodiment; and

FIG. 12

a screw conveyor according to FIG. 11 with cylindrical housing

shows.

The invention will now be described in detail in the form of embodiments with reference to said figures. In the individual figures, the same technical elements are designated by the same reference numerals. A reference number without a comma refers to a first embodiment, while a reference number refers to a second embodiment of the inventive method for producing a screw tube conveyor.

The FIGS. 1 and 8th relate to the invention in general and relate to all embodiments. In contrast, concern the Figures 2-7 the first and the FIGS. 9-12 the second embodiment.

FIG. 1 shows a screw tube conveyor 100 produced by the process according to the invention. It comprises a cylindrical rotary tube 110 with internal screw helix 120 for conveying and mixing a bulk material. The bulk material is introduced into the screw tube conveyor 100 at one end of the screw tube conveyor via an inlet 180 and, after it has been transported in the direction of transport R by rotating the screw tube conveyor, leaves it via an outlet 190.

The inventive method for producing the in FIG. 1 The auger tube conveyor shown below will be described with reference to FIGS FIGS. 2 to 8 described in more detail.

The method according to the invention provides, in a first step, for the production of a one-piece blank, from which the screw tube conveyor is later formed. The blank is preferably made from flat sheet 0.3 to 0.8 mm thick, by making this sheet e.g. punched out according to the contour of the blank or by means of a cutting device, e.g. a laser beam source is cut.

The blank for the method according to the invention consists, as in FIG. 2 The base portion is defined by a parallelogram-shaped configuration by a first pair of opposite edges 1a, 1b and by a second pair of opposite edges 2a and 2b. On the base portion bend lines 115 are provided _i between the second pair of edges 2a, 2b and parallel with these edges running. The lugs 122 integrally formed on the side of the base section are formed between two adjacent bending lines or between one of the edges 2a, 2b of the second pair of edges and a respective adjacent bending line 115 _{i = 1} , 115 _{i = 9} on the base section.

The tabs 122 may be provided on both edges 1a and 1b of the first pair of edges or on only one of these edges. Furthermore, the tabs can be either adjacent to each of these margins or only isolated, in the sense of not adjacent to each other. In the event that two adjacent tabs are provided on one of the edges, then a V-shaped recess 117 is provided between these two tabs, which is aligned in each case on the jointly associated bending line 115 _i and the two adjacent tabs separated from each other. The opening angle α between the two adjacent tabs can be between 0 ° and 180 °. In FIG. 2 For example, the tabs are all trapezoidal in shape. The legs 122a and 126a of the offset to the base portion 112 - opposite trapezoidal tabs 122, 126 lie on a straight line g. This has the advantage that a cutting tool for cutting the legs 122a, 126a only lifted to bridge the base portion, but not curved, which simplifies the production of the blank is simplified.

Not all opening angles α _{i of} a blank need to be the same. The same applies to the Laschenknickwinkel γ _i and the Mantelknickwinkel δ _i .

After the just described first step of the method according to the invention, ie the production of the in FIG. 2 shown blank, this blank is in a second process step, as in FIG. 3 shown in that the tabs 122 in each case by a lashing angle γ relative to the base portion 112 along the edge 1a, 1b, at which the tab is integrally connected to the base portion, is folded over. It then arises in the FIG. 3 shown structures.

In a third process step, finally, the in FIG. 3 shown structures and in particular the base portion 112 along said bending lines 115 _i each kinked by a lateral bending angle δ _i .

In FIG. 4 the base section is only kinked twice, while in the FIGS. 4 and 5 is shown kinked at all bending lines 115 _i . As in the FIGS. 5 and 6 1, the original base section of the blank then forms a helical jacket section 111 of the rotary tube 110, and the previously folded-over tabs 122 then each form segments of the screw helix 120 arranged in the interior of the rotary tube.

In the FIGS. 5 to 7 It is clear that the base portion 112 must be formed parallelogram-shaped, if the screw conveyor produced according to the invention should have a slope> 0, as in the FIGS. 5 to 7 shown.

In the FIGS. 5 and 6 Furthermore, it can be seen that the individual adjacent and previously folded over tabs 122 are now arranged side by side "in abutment" and thus form the helix spiral 120. Thus, the adjacent tabs are abutting each other, it is necessary that in the FIGS. 3 and 4 shown individual jacket bending angle δ _i amount equal to the opening angles α also shown there α of the V-shaped cuts 117 between each two adjacent tabs. Furthermore, it is necessary that as in FIG. 2 illustrates that the adjacent tabs on one of the edges 1a, 1b of the base portion 112 over a length L _u , which corresponds to the circumference of the rotary tube 110, satisfy the following conditions: The opening angle α _i with i = 1-9 of the V-shaped notches 117 between each two adjacent tabs add up together with the two limiting angles β ₁ and β ₂ together 360 °. In this case, the limiting angles β ₁ and β _{2 are} respectively measured between the limbs of the outer flaps and the plumb lines L ₁ , L ₂ , which are perpendicular to the edges _{1 a} , ₁ b of the base portion 112.

If the said angle sum α _i + β ₁ + β _{2 is} smaller than 360 ° and if the associated sheath bending angles δ _i at the associated bending lines 115 _{i are} greater than the respective opening angles α _i in the individual case, overlapping occurs in these individual cases two adjacent tabs in the formation of the screw tube conveyor (not shown).

Alternatively, a jacket bending angle δ _{i may be} smaller than an associated opening angle α _i ; This then has the consequence that during the manufacture of the screw conveyor between the two lugs involved a gap or a V-shaped gap remains. Bulk material may pass through the gap, which may contribute to improved mixing of the bulk material. Such a gap is in FIG. 6 designated by the reference SP.

If a tubular aperture 130, as in FIG. 6 shown inside the auger tube conveyor, the edges 124 of the trapezoidal tabs 122 facing the base section must be cut in the form of a circular arc. The position of the circular arc with respect to the base portion 112 and the radius r of the circular arc are respectively suitably to choose. If the auger conveyor has more than one gear, as in the FIGS. 5 to 7 shown, it is advantageous that parallel to each other and adjacent tabs 122 _{i = 1} , 122 _{i = 10 are} joined together. Advantageously, this joining takes place in the form of a spot welded joint 129.

FIG. 7 shows an inventive screw tube conveyor in an external view. The screw tube conveyor 100 shown there consists of a plurality of longitudinal sections produced according to the invention, which are joined together in each case at the connection points V ₁ -V ₄ in the axial direction. The individual longitudinal sections T ₁ -T ₄ each have only a relatively short axial extent, whereby an assembly of the individual courses of a longitudinal section with each other at the parallel tabs, for example, by the mentioned point welds, is simplified.

It is in Fig. 7 to recognize that at the end portions E of the screw conveyor, the edges 1a, 1b of the base portion 112, which forms the lateral surfaces of the rotary tube 110 after bending along the bending lines, - are tapered acute-tapered - in deviation from the basic parallelogram. This makes it possible for the rotary tube 110 to terminate in a plane perpendicular to the axial orientation of the rotary tube. This flat conclusion at the two ends of the screw conveyor 100 there allows the attachment of a flange, which is preferably connectable to the existing there, also in the said plane extending tabs. The flange 140 may be in the form of a gear, as for the left end of the in FIG. 7 shown screw tube conveyor 100 is shown. This gear is for rotating the screw conveyor 100 with a pinion 151 engageable. The pinion is part of a drive means 150 for driving the screw tube conveyor 100. The flange 140 may also be formed in the form of a race 142, as for the right end of the in FIG. 7 shown screw conveyor 100 is shown. The race is used there for rotatably supporting the screw conveyor 100 on preferably conically shaped rollers 160. The gear and the race are preferably formed concentrically and coaxially with the same radius.

• In einem ersten Schritt wird ein einstückiger Zuschnitt gemäß Figur 8 hergestellt; diesbezüglich wird auf die Figur 2 und die zugehörige Beschreibung verwiesen. Der einzige Unterschied zwischen dem Zuschnitt gemäß dem zweiten Ausführungsbeispiel und dem Zuschnitt gemäß dem ersten Ausführungsbeispiel besteht darin, dass die seitlichen Laschen 122' bei dem zweiten Ausführungsbeispiel gegenüber dem ersten Paar von Rändern 1a, 1b vorzugsweise konvex in Form eines Kreisbogens ausgebildet sind, wie dies in Figur 8 angedeutet ist.
• In einem zweiten Schritt werden dann die Laschen 122' um einen Laschenknickwinkel γ' gegenüber dem Basisabschnitt 112' vorzugsweise um 90° geknickt.
• In einem dritten Verfahrensschritt wird dann der Basisabschnitt 112' entlang der Biegelinien 115'_i jeweils um einen Mantelknickwinkel δ' so geknickt, dass der Basisabschnitt einen helixförmigen Mantelabschnitt des Drehrohres 110' bildet, wie dies in Figur 9 dargestellt ist. Die zuvor umgeknickte mindestens eine Lasche 122' bildet dann einen radial nach außen stehenden Kamm 113' auf dem helixförmigen Mantelabschnitt 111'. Durch dieses beschriebene Knicken des Basisabschnittes entsteht mindestens ein Gang des Drehrohres 110'; es können jedoch auch eine Vielzahl von parallel angeordneten Gängen gebildet werden, wie dies in Figur 11 dargestellt ist.
• In einem vierten Verfahrensschritt gemäß dem zweiten Ausführungsbeispiel werden der helixförmige Mantelabschnitt 111' und eine in Figur 10 dargestellte helixförmige Schraubenfläche 125' zum Herstellen des Schneckenrohrförderers - wie er in Figur 11 dargestellt ist - ineinander geschoben. Der Kamm 113' überdeckt bzw. überlappt dann die Schraubenfläche 125' an ihrer Peripherie und kann dort mit dieser zusammengefügt, vorzugsweise punktverschweißt werden. Gleichzeitig bildet derjenige Teil der helixförmigen Schraubenfläche 125', welcher nicht von dem Kamm bedeckt wird, die Schneckenwendel 120' im Inneren des Schneckenrohrförderers.

Hereinafter, the second embodiment of the invention for producing the screw tube conveyor with reference to the FIGS. 8-12 described in more detail. For the description of the figures, as far as possible, reference is made to analogous figures relating to the first exemplary embodiment, the same technical features being provided with the same reference numerals as the single one Difference that the reference numerals for the corresponding elements in the second embodiment have a single quote. The method according to the second exemplary embodiment comprises the following steps:

• In a first step, a one-piece blank according to FIG. 8 produced; in this regard is on the FIG. 2 and the related description. The only difference between the blank according to the second embodiment and the blank according to the first embodiment is that the lateral tabs 122 'in the second embodiment are preferably convex in the form of a circular arc as compared to the first pair of edges 1a, 1b in FIG. 8 is indicated.
• In a second step, the tabs 122 'are then bent 90 ° relative to the base portion 112' by a tab angle γ '.
• In a third method step, the base section 112 'is then bent along the bending lines 115' _i by a lateral bending angle δ 'such that the base section forms a helical jacket section of the rotary tube 110', as shown in FIG FIG. 9 is shown. The previously folded over at least one tab 122 'then forms a radially outwardly standing comb 113' on the helical shell portion 111 '. As a result of this described bending of the base section, at least one passage of the rotary tube 110 'is formed; However, it can also be formed a plurality of parallel gears, as in FIG. 11 is shown.
• In a fourth method step according to the second embodiment, the helical jacket portion 111 'and a in FIG. 10 shown helical screw surface 125 'for producing the screw tube conveyor - as in FIG. 11 is shown - pushed into each other. The comb 113 'then overlaps or overlaps the screw surface 125' on its periphery and can be joined together there, preferably spot-welded. At the same time, that part of the helical screw surface 125 ', which is not covered by the comb, forms the helix 120' inside the screw tube conveyor.

The screw tube conveyor produced according to the second embodiment offers - compared to the screw conveyor produced according to the first embodiment - the advantage that the joining of the tabs or the comb with the screw surface 125 'is very easy, because these areas are accessible from the outside. Therefore, a plurality of juxtaposed passages of the screw conveyor can be simultaneously assembled or manufactured in the screw conveyor produced according to the second embodiment, while the number of joinable in a step gears in the first embodiment is limited, because of the local there only limited accessibility of the tabs to be connected in Inside the auger tube conveyor.

For hygienic reasons, the screw conveyor can according to FIG. 11 for example, in a cylindrical housing 170, see Fig. 12 be wrapped, whereby the radially outward comb is covered for a viewer. The housing 170 rests on the comb 113 'and is preferably joined together, eg soldered. This creates between the housing 170, the comb 113 'and the base portion 112', a helical cavity 172. The cavity 172 is preferably evacuated, for example, for insulation purposes; It is then a thermal treatment of the bulk material inside the screw conveyor more efficient possible. The comb 113 'supports the housing 170 against the base portion 112', even with negative pressure in the cavity 172 due to the vacuum. It may also be possible to simply solder the housing 170 with the comb 113 'under vacuum. Also on the screw conveyor manufactured according to the second embodiment, the flanges and the pinion can be mounted as shown in FIG FIG. 7 is shown by way of example for the screw tube conveyor produced according to the first embodiment.

Claims (22)

1. A method for producing a screw-tube conveyor (100) in the form of a cylindrical rotary tube (110) with an internal screw spiral (120) for conveying and mixing a bulk material, comprising the steps:

   Producing a one-piece blank comprising a base portion (112) in the form of a convex quadrangle with at least one lateral fin (122),

   wherein the base portion is defined by a first and a second pair of respectively opposing edges ((1a, 1b); (2a, 2b)), wherein bending lines (115'i) are provided on the base portion between the second pair of edges (2a, 2b), and which bending lines are running parallel to said edges, and whereby the at least one fin (122) is integrally formed with the base portion on at least one of the edges (1a, 1b) of the first pair at the level between two adjacent bending lines, or between one of the edges (2a, 2b) of the second pair and an adjacent bending line (115i);
   bending over the fin (122) about a fin bending angle γ with respect to the base portion (112) along the one edge (1a, 1b) at which the fin is integrally connected with the base portion; and
   bending the base portion (112) along the bending lines (115i) each by a casing bending angle δ in such a manner that the base portion forms a helical casing portion (111) of the rotary tube (110), and that the previously bent-over fin (122) forms a segment of the screw spiral (120) arranged inside the rotary tube.
2. The method for producing a screw-tube conveyor (100') in the form of a cylindrical rotary tube (110') with an internal screw spiral (120) for conveying and mixing a bulk material, comprising the steps:

   Producing a one-piece blank comprising a base portion (112') in the form a concave quadrangle with at least one lateral fin (122'),

   wherein the base portion is defined by a first and a second pair of respectively opposing edges ((1a, 1b); 2a, 2b)), wherein bending lines (115'i) are provided on the base portion between the second pair of edges (2a, 2b), and which bending lines are running parallel to said edges, and whereby the at least one fin (122') is integrally formed with the base portion on at least one of the edges (1a, 1b) of the first pair at the level between two adjacent bending lines, or between one of the edges (2a, 2b) of the second pair and an adjacent bending line (115i');
   bending over the fin (122') about a fin bending angle γ with respect to the base portion (112') along the one edge (1a, 1b) at which the fin is integrally connected with the base portion;
   bending the base portion (112') along the bending lines (115'i) each by a casing bending angle δ in such a manner that the base portion forms a helical casing portion (111') of the rotary tube (110'), and that the previously bent-over fin (122') forms a comb (113') radially projecting outwards on the helical casing portion (111');
   pushing the helical casing portion (111') and a helical screw face (125') into one another to form the screw-tube conveyor in such a manner that the comb (113') overlaps the screw face at the periphery of the latter and that a part of the screw face not covered by the comb represents the screw spiral inside the screw-tube conveyors; and
   joining the screw face and the comb at the overlapping regions to form the screw-tube conveyor (100').
3. The method according to claim 2, characterized in that the screw-tube conveyor (100') is installed in a preferably cylindrical housing.
4. The method according to any one of the preceding claims, characterized in that for the fin bending angle γ, γ' is given: γ = 90° and γ' = 90°.
5. The method according to any one of the preceding claims, characterized in that producing the blank takes place in that the material for the blank is punched or, e.g., cut with a laser beam.
6. A blank for producing a screw-tube conveyor (100, 100') in the form of a cylindrical rotary tube (110, 110') with an internal screw spiral (120, 120'), comprising:

   a base portion (112, 112') in the form of a convex quadrangle, wherein the base portion is defined by a first and a second pair of respectively opposing edges ((1a, 1b); 2a, 2b)), and wherein bending lines (115i, 115'i) are provided on the base portion between the second pair of edges (2a, 2b), and which bending lines are running parallel to said edges; and

   at least one fin (122, 122') which is integrally connected with the base portion on at least one of the edges (1b) of the first pair at the level between two adjacent bending lines, or between one of the edges (2a, 2b) of the second pair and an adjacent bending line (115i, 115'i).
7. The blank according to claim 6, characterized in that the blank is formed coplanar with the base portion (112, 112') and the at least one fin (122, 122') before it is bent to form the screw-tube conveyor.
8. The blank according to any one of claim 6 or claim 7, characterized in that the blank is made from metal, preferably from sheet metal with a thickness of 0.3 to 3 mm.
9. The blank according to any one of the claims 6 to 8, characterized in that the fins (122, 122') are formed at least partially adjacent on the at least one of the edges (1a, 1b), or only here and there in the sense of not adjacent.
10. The blank according to any one of the claims 6 to 9, characterized in that - if at least two adjacent fins are integrally formed on one of the edges of the base portion - always two of the adjacent fins are separated from one another by a notch (117, 117') which is oriented towards the jointly allocated bending line (115i, 115'i).
11. The blank according to any one of the claims 6 to 10, characterized in that the at least one fin (122, 122') is formed trapezoidal.
12. The blank according to claim 11, characterized in that the trapezoidal fin' s (122, 122') edge (124, 124') opposing the base portion is cut in the form of a concave or in form of a convex circular arc.
13. The blank according to any one of the claims 6 to 12, characterized in that the fins (122₁, 122₁₀) are arranged on the two opposing edges (1a, 1b) of the first pair of edges in such a manner that the same are abutting each other at least partially after a subsequent bending over of the fins with respect to the base portion and a subsequent bending of the base portion along the bending lines to form two adjacent windings (screw flights) of the screw-tube conveyor.
14. The blank according to any one of the claims 6 to 13, characterized in that for at least one end section (E) of the base portion (112), which forms an end of the screw-tube conveyor after bending over the base portion (112) along the bending lines, the two opposing edges (1a, 1b) of the first pair of edges are cut in an acute-angled shape.
15. A screw-tube conveyor (100) in the form of a cylindrical rotary tube (110) with an internal screw spiral (120), wherein said screw-tube conveyor is produced from the blank according to any one of the claims 6 to 14 according to the method according to any one of the claims 1 to 5.
16. The screw-tube conveyor (100) according to claim 15, characterized in that the screw-tube conveyor has a plurality of screw flights (G_h).
17. The screw-tube conveyor (100) according to claim 16, characterized in that the individual screw flights (G_h) of the screw-tube conveyor are at least partially connected with one another in that the fins (122₁, 122₁₀) which then are abutting one another inside the screw-tube conveyor are joined to one another, preferably (spot) welded, or in that the parts comb, periphery of the screw face, comb, which then are abutting one another on the outside of the screw-tube conveyor, are joined to one another.
18. The screw-tube conveyor (100) according to any one of claim 16 or claim 17, characterized in that the individual screw flights (G_h) of the screw-tube conveyor are at least partially connected with one another by a helical weld seam (S) on the casing of the screw-tube conveyor.
19. The screw-tube conveyor according to any one of the claims 15 to 18, characterized in that the screw-tube conveyor has a flange (140) on at least one of its ends, which flange is preferably attached, e.g. welded, to the bent-over fins in the region of the end of the screw-tube conveyor.
20. The screw-tube conveyor according to claim 19, characterized in that the flange (140) is formed at one end of the screw-tube conveyor in the form of a gear wheel which, for rotating the screw-tube conveyor, can be engaged with a pinion (151) driven by a drive unit (150).
21. The screw-tube conveyor (100) according to any one of claim 19 or claim 20, characterized in that the flange is formed as a raceway (142) at an end opposing the gear wheel, if necessary, for rotatably supporting the screw-tube conveyor (100) on preferably conically formed rollers (160).
22. The screw-tube conveyor (100) according to any one of the claims 15 to 21, produced according to the method according to claim 2 or claim 3, characterized by a hollow space (172) between the housing (170), the comb (113'), and the base portion (112'), wherein the hollow space (172) is preferably evacuated.

Images