EP3691810B1 - Method for producing a rolled edge, use of such method for producing an aerosol dome for a spray container and such a spray container - Google Patents

Description

TECHNICAL AREA

The present invention relates to a method for producing a rolled edge from an edge section of a pipe, in which a crimping punch moves into the edge section and crimps it into a roll.

Methods of this type are used, inter alia, in the production of so-called aerosol domes for spray bottles, a tubular section of these domes being shaped into precisely such a rolled edge for receiving a valve disk. Especially here, high demands are placed on the precision and thin sheets of only a few tenths of a millimeter thick have to be processed.

STATE OF THE ART

In today's production of the rolled edge on the aerosol domes, a flanging die with a certain radius moves into a pipe section previously produced by drawing on the aerosol dome and flanges the edge of this pipe section into a roll. The shape and size of the rolled edge are largely determined by the geometry of the crimping die and its mentioned radius. In this forming process, however, the initial zone of the rolled edge does not regularly have the desired radius, but rather a straight shape. A kind of kink arises between the rather straight starting zone and the adjoining radially deformed zone. This effect is caused by the inherent stability of the sheet and is therefore more pronounced the thinner and harder the sheet is. In addition, there are irregularities in the material and in the tool, which have a similar effect and generally cause uneven, uncontrolled deformations.

The relationships described above should be based on the Figures 1 , 2a) - 2e) and 3 can be shown in more detail.

Fig. 1 shows, in a longitudinal section, an aerosol dome 10 with a pipe section 11 and a crimping die 21 with a radius 22 of a forming tool 20 (not shown in detail). On the left-hand side of FIG Fig. 1 is the initial state with the as yet undeformed pipe section 11 and the crimping punch 21 in its starting position shown. The right part of Fig. 1 shows the crimping die 21 in its end position. When the punch 21 is moved between the start and end position, the pipe section 11 (or, depending on the length of the pipe section, at least one edge section thereof) is deformed along the radius 22 to form a roller 12.

the Figures 2a) - 2e ) each show an enlarged section A of Fig. 1 Details of the rolling process. Noticeably arises at the transition from Fig. 2a ) to Fig.2b ) with the formation of a practically straight initial zone 14, the aforementioned kink 13, which in the further forming process according to the Figures 2c) - 2e ) is unfavorably preserved. In terms of forming technology, the starting zone 14 represents an uncontrolled geometry zone. It leads to a variable height H (cf. Fig. 2e ) of the rolled edge 12 and thus also to an uncontrolled, irregular edge geometry 15, as shown in FIG Fig. 3 is shown in a partial view of the reshaped aerosol dome.

To solve this problem, the EP-A-1 372 880 before the process as in the Figures 4 - 6 structure specified: In Fig. 4 (shows in a longitudinal section an aerosol dome with a pipe section in a rolling tool in two positions, namely still undeformed on the left and completely rolled on on the right) again denotes an aerosol dome with a pipe section 11, which here, however, is placed in a rolling tool 30. This comprises a roll-on stamp 31 with a radius 32, at least one hold-down 33, several counter-holders 34 and a corresponding number of slides 35. The counter-holders 34 can be designed as four radially movable segments that together delimit or release a circular opening. To the left of Fig. 4 the initial state is shown with the as yet undeformed pipe section 11 and the roll-on die 31 in its starting position. The parts 33-35 are, however, already in their end or functional position. They achieve this from a release position shown in dashed lines by first moving the hold-down device 33 together with the counterholders 34 down to the stop with an annular rim 16 of the aerosol dome. The slides 35 are then moved down to the hold-down 33. Since they are coupled to the counterholders 34 via an inclined surface, they push the counterholders 34 radially inward into their illustrated end position for the embossing process. The right part of Fig. 4 shows the roll-on die 31 in its end position. When the roll-on die 31 is moved between its start and end position, an initial section 14 of the pipe section 11 is rolled on and provided with the radius 32. Thereafter, the roll-on die 31 is withdrawn again from the pipe section, which Slide 35 moved upwards, move the counterholders 34 radially outwards, move the hold-down device 33 upwards and the aerosol dome 10 is thereby released.

As described above, the aerosol dome 10 or its pipe section 11 can then be rolled on analogously to that already based on FIG Figures 1 and 2 explained method are further reshaped, wherein Fig. 5 one of the Fig. 1 shows corresponding representation. As can be seen, however, in the starting position shown on the left, the rolled-on starting zone 14 of the pipe section 11 is flush with the radius 22 of the flanging punch 21. For this purpose, the radii 22 of the crimping die 21 on the one hand and 32 of the rolling die 31 are preferably also dimensioned to be the same. During further rolling with the crimping die 21, the starting zone 14 retains its controlled radius, as shown in the detailed illustration B of FIG Fig. 5 in Fig. 6 is shown, which shows the finished rolled edge portion.

The problem with such methods according to the prior art is, among other things, that they cannot be carried out without material stresses and the associated cracks and elongations at break, especially in the case of starting material with greater strength. In addition, it can be seen that the rolled edge is wavy because the collar does not take on the curling radius.

From the U.S. 4,113,133 a method for producing the rolled edge on a pressure vessel is known, wherein the rolled edge extends outward from the container wall and has a segment of a circle of at least 180 ° in section through the container axis, into which the end portion of the rolled edge is guided, the end portion in The section through the container axis is rectilinear, has a length which is greater than the radius of the segment-shaped section and forms an acute angle with the container axis that closes to the bottom of the pressure container. The method is characterized in that the edge is brought to the desired opening diameter, that the end section of the edge is bent straight outwards perpendicular to the container axis, the tool freely shaping and so the section is not supported downwards, then forming a point Is bent downwards at an angle with the container wall and that the edge is then rolled up to form the segment-shaped section.

From the DE 20 2013 100 529 U1 there is known a crimping machine for cans having a container and a lid; wherein the crimping machine has at least one crimping device that rolls an already folded edge radially from the outside and for this is designed to connect the lid and the container to one another by a crimping process. The tool comprises a roller which acts radially from the outside and is designed to carry out the crimping process on the edges of the lid and the container; the method is characterized in that the (at least one) crimping device comprises a pneumatic actuator which is designed to move the roller so that it is brought into contact with the can and carries out the crimping process.

DISCLOSURE OF THE INVENTION

The subject of the present application is accordingly a method for producing a rolled edge from a cylindrical edge section of a pipe, in which method an initial zone of the edge section is rolled by a positively controlled tool or, better, turned into a straight flange and then a flanging punch is inserted into the rolled or, better, turned over Retracts the edge section and flanges it into a roll. The process takes place in just these two steps, i.e. H. the cylindrical edge section, which may have been processed beforehand (for example, surface treatment, adjustment of the concentricity, etc.) but is introduced into the process as a cylindrical edge section, is processed in precisely these two steps, namely by folding over in the first step and then in the second step this folded edge is rolled. No further steps are planned. Accordingly, the procedure exclusively comprises these two steps. It is therefore a two-stage process for producing a rolled edge from a cylindrical edge section of a pipe, which process consists of the aforementioned first step and the aforementioned second step in order to provide the final rolled edge intended for use.

The method is characterized in that in the said first step of folding the starting zone of the edge section by means of the one folding die, preferably axially at least partially retracting into the opening of the edge section in the first step, and preferably comprising a counterholder, by an angle (a) in the range of 75-105 ° is folded over from the axial direction to a substantially radial circumferential flange. The angle α of this flange is preferably in the range of 80-100 °, preferably in the range of 85-95 °. The tilting die has a tilt angle corresponding to the tilting angle mentioned with respect to the axis of the edge section inclined plane support surface and the counter holder via a substantially parallel to this also planar counter surface. If the folding die is inserted into the cylindrical edge section from above, the counter surface of the counter-holder supports the folded section downwards and thus allows a controlled process with small bending radii even with hard materials thanks to the supported process management.

The problem with the completely original method outlined above was that an aesthetically unsatisfactory edge resulted at the end of the rolled edge. This problem could be solved by the procedure according to the EP-A-1 372 880 can be largely eliminated. However, it has been shown that both processes, especially with the transition to harder and / or thinner sheets as the starting material, which are in demand today, cause problems if you really only want to use two steps for the entire rolling of the edge and want to do without further intervening Avoid procedural steps that entail additional complications and additional costs. Especially if, for example, tinplate of the type TH520 or TH500 (or materials with an even higher yield point and / or tensile strength) are used, cracks occur as a result of the material stresses triggered by the lower elongation at break in the two-stage process according to the prior art. In addition, the edge becomes wavy, as the collar does not take on the flange radius.

So that materials with the above-mentioned higher yield point and / or tensile strength can be used, is preferably used for the first step of folding, for example in contrast to the procedure described in U.S. 4,113,133 which cannot process hard materials, not freely formed as there (only with a punch), but reshaped with support, ie the edge is turned over by an angle (a) by a tool comprising a folding punch and a counter holder. With these materials, free shaping does not allow tilting with small radii.

Surprisingly, it has now been found that these problems can be solved in particular within the two-stage process, and consequently the hard materials mentioned and even harder materials can also be used without the problems mentioned if the starting area of the pipe is not rolled on, but rather essentially is bent by 90 °. This stabilizes the end of the collar and the formation of waves through the anisotropy. In addition, the The initial area of the collar is relieved of the material tension caused by the processing.

A preferred embodiment of the method is characterized in that the bending radius r between the circumferential flange and the axial section adjoining it is smaller than twice the material thickness s of the cylindrical edge section. In other words, the leg length of the 90 ° bend is preferably defined in a ratio related to the material thickness.

Furthermore, the bending radius r is preferably in the range of 0.5-1.5 times, particularly preferably in the range of 0.75-1.25 times the material thickness (s) of the cylindrical edge section.

Another preferred embodiment is characterized in that the radial length q of the flange is in the range of 2-5 times, preferably in the range of 3-4 times or 3-3.5 times the material thickness (s) of the cylindrical edge section. The 90 ° flange that is initially created is preferably hidden in the interior of the roll during the flanging process. Correspondingly, the method according to a further preferred embodiment is characterized in that the essentially linear section of the flange is placed in the interior of the roll by the crimping die during the rolling following the folding, and is preferably directed into the roll in an essentially radial direction.

The material thickness of the edge section is preferably in the range of 0.05-1 mm, preferably in the range of 0.15-0.4 mm, particularly preferably in the range of 0.18-0.34 mm.

The material of the edge section is typically sheet steel, preferably tinplate.

The material used for the edge section is also preferably sheet steel with a yield point (determined in accordance with EN 10202: 2001, in particular Chapter 8.2 and the measurement method in accordance with DIN EN 10002-1: 2001) of at least 500 MPa, preferably at least 520 MPa, particularly preferably at least 550 MPa. According to a preferred embodiment, the material used for the edge section can be sheet steel with a tensile strength (determined in accordance with EN 10202: 2001, in particular Chapter 8.2 and the measuring method in accordance with DIN EN 10002-1: 2001) of at least 500 MPa, preferably of at least 550 MPa, particularly preferably act at least 575 MPa.

Typically, the material of the edge section is tinplate of the type TH520 (material number 1.0384), TH550 (material number 1.0373), TH580 (material number 1.0382), TH620 (material number 1.0374), or the corresponding TS types, each in accordance with DIN EN 10202: 2001 Alternatively formulated of type DR8, DR8, DR8.5, or DR9, each according to AISI / ASTM 623. The corresponding compositions and properties of these materials are defined in the specified standards, the corresponding disclosure in the specified standards is expressly used for the definition of the specific Materials mentioned here are included in the present disclosure content.

So that the folded edge can then be effectively and reliably rolled, the crimping die preferably has an encircling angle of at least 100 °, preferably of at least 120 °.

• Verstellen der äusseren Gegenhalter radial nach innen bis auf Anschlag mit dem Rohrabschnitt,
• Einfahren des Umlegestempels in den Rohrabschnitt unter Umlegen von dessen Anfangszone,
• Ausfahren des Umlegestempels aus dem Rohrabschnitt,
• Verstellen der äusseren Gegenhalter radial nach aussen unter axialer Freigabe des Rohrabschnitts.

The tool normally has several outer counterholders that can be radially adjusted in relation to the pipe axis as well as a transfer die and rolling is carried out in the following steps:

• Adjustment of the outer counter holder radially inwards until it stops at the pipe section,
• Insertion of the folding punch into the pipe section by folding over its starting zone,
• Moving the folding die out of the pipe section,
• Adjustment of the outer counter-holder radially outwards while axially releasing the pipe section.

There can be 3, 4, 5, or 6, preferably 4, outer counterholders distributed over the circumference, each of which has a radial arm and clamp areas arranged radially on the inside thereof, which essentially encircle the axial section.

The rolled edge is typically attached to a tubular section of an aerosol dome for spray cans for receiving a valve disk, it being possible, if necessary, to carry out additional forming steps, in particular for preparing the attachment to the spray can, in parallel or in addition to the steps discussed above.

Preferably, when folding down, the folding die and counterholder lie around the edge section in a form-fitting manner.

The present invention further relates to the use of such a method for producing a rolled edge, in particular for producing an aerosol dome with such a rolled edge for a spray can.

Last but not least, the present invention relates to a rolled edge, in particular as part of an aerosol dome for a spray can, produced according to a method as set out above, or a spray can with such a rolled edge.

Further embodiments are given in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 - 6

die bereits erläuterten Figuren zur Verdeutlichung der Verhältnisse beim Stand der Technik;

Fig. 7

eine Darstellung eines Aerosoldomes und eines Umlegestempels sowie Schieber und Gegenhalter in zwei Stellungen, und zwar links noch unverformt und rechts umgelegt, d.h. wobei der Aerosoldom eine ungelegte Anfangszone aufweist;

Fig. 8

eine Aufsicht auf das Umlegewerkzeug;

Fig. 9

eine Darstellung eines Aerosoldomes im Rollwerkzeug mit Bördelstempel, wobei jedoch der Aerosoldom bereits eine umgelegt Anfangszone aufweist;

Fig. 10

in einer Ausschnittsvergrösserung gemäss B in Figur 9 im Detail einen fertig gerollten Rolland nach der Erfindung;

Fig. 11

eine Detaildarstellung des umgelegten Abschnittes vor der Behandlung mit dem Bördelstempel.

Preferred embodiments of the invention are described below with reference to the drawings, which are only used for explanation and are not to be interpreted as restrictive. In the drawings show:

Figs. 1-6

the figures already explained to clarify the relationships in the prior art;

Fig. 7

a representation of an aerosol dome and a folding punch as well as slide and counter holder in two positions, namely still undeformed on the left and folded over on the right, ie the aerosol dome having an unplaced starting zone;

Fig. 8

a plan view of the folding tool;

Fig. 9

a representation of an aerosol dome in the rolling tool with a crimping die, but the aerosol dome already has a folded starting zone;

Fig. 10

in an enlarged section according to B in Figure 9 in detail a completely rolled roll-up edge according to the invention;

Fig. 11

a detailed representation of the folded section before treatment with the crimping stamp.

DESCRIPTION OF PREFERRED EMBODIMENTS

the Figures 7-11 show, in different representations and in different process stages, the newly proposed process for producing a rolled edge, now also possible using materials that are harder than those previously possible. In Figure 7 the step of folding over the starting zone 14 in the tool is shown, on the left side still with the tool open, and on the right side already in the tool state in which the edge is folded over to form a circumferential flange 41.

As can be seen on the left, the aerosol dome 10 or the axial section 42 is encompassed laterally or around the circumference by counter-holder elements 34, and a folding die 37 with a narrow radius 36 is inserted into the opening along the axis 44 from above. In this case, the starting area 14 is turned over by a right angle and, with the formation of a comparatively sharp edge, essentially by a right angle, i.e. approx. 90 °, as shown in FIG Figure 7 can be seen on the right.

Figure 8 shows a possible tool for performing this first operation of generating the rolled edge in a plan view. It can be seen here that there are a total of 4 slides 35 which control the counterholders 34. The counterholders 34 each have a radial arm 38, based on the tool axis 44, and over areas 39 encompassing the axial section 42 of the workpiece to a certain extent, each encompassing a circumference of less than 90 °.

In the next step, the actual rolled edge is created, this is in Figure 9 shown. Again on the left-hand side the state when the tool is still open, that is to say in the state where the crimping punch 21 has been inserted into the opening of the prepared dome, but has not yet reshaped the edge area. The crimping die 21 has a relatively large enclosure angle 48 of approximately 120 °. Further tool elements, in particular counterholders, can also be provided in this step, but are not mandatory. The crimping die 21 then moves axially into the opening and now rolls the axial section 42 to form the actual roller 12.

As in the detailed excerpt in Figure 10 can be recognized, the relocated initial zone remains essentially unchanged. The quasi-linear folded area 41 and the sharp bend 40 are essentially retained, but do not interfere, since the edge is rolled so far towards the roller 12 that the quasi-linear area 41 points to a certain extent into the interior 47 of the roller 12. In this way, there are no disruptive, in particular aesthetically problematic effects, and safety is also comprehensively guaranteed, since a possibly sharp edge is laid inside the roll.

For the functioning of the process, the material thickness and radius as well as the bending length are advantageously specifically coordinated. The individual parameters for this are in Figure 11 shown. On the one hand the deflection angle a, on the other hand the bending length q, i.e. the radial extension of the flange, and the material thickness s Direction in the area of the axial section 42 or the radial direction 46, or - if not exactly 90 ° - in the essentially radial direction (46) of the folded area 41. REFERENCE LIST 10 Aerosol dome 38 radial arm of 34 11 Tube or edge section of the aerosol dome 39 Bracket range of 34 40 sharp bend in 12 12th role 41 quasi-linear range of 14 13th Kink 42 axial section 14th Starting zone 43 Dome section 15th Edge geometry 44 Axis of symmetry 16 Ring edge 45 axial direction in area 42 20th Forming tool 21 Crimping stamp 46 Direction of the folded area 41 22nd Radius on the crimping stamp 30th Rolling tool 47 Interior from 12 31 Roll-on stamp 48 Enclosure angle of 21 32 Radius on the roll-on stamp 33 Hold-down 34 Counterholder s Material thickness 35 Slider q Bending length 36 Radius on the transfer die r Bending radius 37 Transfer stamp α Tilt angle

Claims (15)

1. Method for producing a rolled edge from a cylindrical edge section (11) of a tube, in which method, in a first step, an initial zone (14) of the edge section (11) is folded over by a positively controlled tool (30) and, in a second step, a flanging punch (21) subsequently moves into the folded-over edge section (11) and flanges the latter to form a roll (12),
   wherein in the first step the initial zone (14) of the edge portion (11) is folded over by the tool (30) comprising a folding over punch (37) and counterholder (34) by an angle (α) in the range of 75-105° from the axial direction (45) to a substantially radial circumferential flange (41)
   characterised in that
   the method of producing a rolled edge from a cylindrical edge portion (11) is in the form of a two-step method and comprises only said first and second steps to provide the final rolled edge for use from the cylindrical edge portion (11) of the tube.
2. Method according to claim 1, characterised in that the bending radius (r) between the circumferential flange (41) and the axial section (42) adjacent thereto is smaller than twice the material thickness (s) of the cylindrical edge section (11), preferably that the bending radius (r) lies in the range of 0.5-1.5 times, more preferably in the range of 0.75-1.25 times the material thickness (s) of the cylindrical edge section (11).
3. Method according to one of the preceding claims, characterized in that the radial length (q) of the flange (41) is in the range of 2-5 times, preferably in the range of 3-4 times the material thickness (s) of the cylindrical edge portion (11).
4. Method according to one of the preceding claims, characterized in that the substantially linear portion (41) of the flange is placed inside (47) the roll (12) by the flanging punch (21) during the rolling following the flanging, and is preferably directed into the roller in a substantially radial direction.
5. Method according to any of the preceding claims, characterized in that the angle (α) is in the range of 80-100°, preferably in the range of 85-95°.
6. Method according to one of the preceding claims, characterized in that the material thickness of the edge portion (11) is in the range of 0.1 - 1 mm, preferably in the range of 0.15-0.4 mm, more preferably in the range of 0.18-0.34 mm.
7. Method according to one of the preceding claims, characterized in that the material of the edge portion (11) is sheet steel, preferably tinplate.
8. Method according to claim 8, characterised in that the material of the edge portion (11) is sheet steel

   with a yield strength, determined in accordance with DIN EN 10002-1:2001, of at least 500 MPa, preferably at least 520 MPa, in particular preferably at least 550 MPa,

   and/or with a tensile strength, determined in accordance with DIN EN 10002-1:2001, of at least 500 MPa, preferably at least 550 MPa, in particular preferably at least 575 MPa,
9. Method according to one of the preceding claims, characterized in that the material of the edge portion (11) is sheet steel, preferably tinplate of the type TH520, material number 1.0384; TH550. material number 1.0373; TH580, material number 1.0382; TH620, material number 1.0374, or the corresponding TS types, in each case according to DIN EN 10202: 2001, and/or DR8, DR8, DR8.5, or DR9, in each case according to AISI/ASTM 623.
10. Method according to one of the preceding claims, characterised in that the flanging punch (21) has a circumferential angle of at least 100°, preferably of at least 120°.
11. Method according to one of the preceding claims, characterized in that the method comprises exclusively the first and second step, and the tool (30) comprises a plurality of outer counterholders (34) radially adjustable with respect to the tube axis (44), as well as a transfer punch (37), and in that the rolling is carried out in the following steps:

    - adjusting the outer counter-supports (34) radially inwards until they come into contact with the pipe section (11),

    - retraction of the transfer plunger (37) into the pipe section (11) while overturning its initial zone (14),

    - extending the transfer punch (37) out of the pipe section (11),

    - moving the outer counterholder (34) radially outwards while axially releasing the pipe section (11),

    wherein preferably 3, 4, 5, or 6 circumferentially distributed outer counter-supports (34) are provided, each having a radial arm (38) and clamp regions (39) arranged radially inwardly thereof and substantially circumferentially surrounding the axial section (42).
12. Method according to any one of the preceding claims, characterized in that the rolled rim is applied to a tubular portion (11) of an aerosol dome (10) for aerosol cans for receiving a valve disc.
13. Method according to one of the preceding claims, characterized in that the roll-over punch (37) and the counterholder (34) roll over the rim section in a form-fitting manner.
14. Use of a method according to any one of the preceding claims for producing an aerosol dome for an aerosol can.
15. Aerosol can or aerosol dome for an aerosol can with a rolled rim produced according to a method according to one of the preceding claims.

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