EP0904865B1 - Method and apparatus for forming a metal band having areas of different thickness across its width - Google Patents

Description

The invention relates to a method for producing a Metal tape with different thicknesses across its width Areas and a device for carrying out the Process. (see e.g. WO-A-9 415 735).

For reasons of economical use of materials and one load-dependent dimensioning of components components that have been used for a long time Area and / or length have a different thickness (Umformtechnik, 7th Aachen Steel Colloquium from 26th to March 27, 1992, "4.2 Rollers optimized for load Longitudinal Profiles "by B.Hachmann, R.Kopp, Aachen). The Preproducts of such components are called "tailored blanks" designated. In practice there is for manufacturing such tailored blanks are fundamentally different Manufacturing processes.

According to a first known method, a tape is in its thickness in sections in an deliverable Roll gap of a roll stand reduced. From a such tape with different thickness can then Cut out blanks for the desired components become. The advantages of such a method exist in that the transitions from the smallest strip thickness to greatest strip thickness are steady. The disadvantage, however, is that the transitions are long because of the delivery of the roll gap cannot take place suddenly. Another disadvantage is that for the delivery of the Rolling gap very large forces are required. On Roll stand must be specially designed to Example of a special compensation device for these expansions of the Have roll stand. In addition, this Process the usual roller speed of do not use for several 100 meters. That is why such process for the production of tailored blanks not suitable.

In addition, it is also known to have a metal band with over its width different thickness ranges thereby produce that in the tape at least one in Strip lengthwise extending strips of reduced thickness is rolled in by means of a pair of rollers, in which one Roll at least a section larger in the axial direction Has diameter than in the rest of the area (DE 33 43 709 A1). It is not known that such a procedure for the production of tailored blanks in practice has prevailed.

On the other hand, in practice it is different Manufacturing process for tailored blanks very much common. This process uses two sheets of different thicknesses, the one Butt joint are welded together. The advantages Such a procedure consists in the minor device engineering effort for that Welding together, so that the process is also suitable for small quantities are suitable. The disadvantages are that there are no smooth transitions from the thinner material to the thicker material, so that the weight saving not taking into account the occurring load is optimal. Add to that the thick jump also a sudden surge in tension from the thicker to the thinner material. After all, because of that to produce the weld Production speed of such tailored blanks is small.

Finally, under "full profile drawing rollers" Forming process known (magazine "DRAHT" 18 (1967), No. 1, pages 33 to 38), in which to produce a Band a full body through a gap made by two freely rotatable or driven rollers are formed, is pulled through. It is not intended Bands with different thicknesses across the width Areas.

Proceeding from this, the object of the invention is a method and an apparatus for producing a Metal tape with different over its width To create thickness ranges and a smooth transition that a low manufacturing cost at one comparatively high production speed allowed.

This task is done with regard to the procedure solved that in a band with constant across its width Thickness at least one in the longitudinal direction of the tape extending strip of small thickness molded thereby is that the tape by at least one, of one Front of a work roll and a support roller formed drawing gap is drawn, the work roll with its axis of rotation so inclined to the band plane is employed that when pulling the tape Work roller with its face on the belt a force exercises transversely to the tape longitudinal direction. The device for This method is carried out according to the invention characterized by guide and traction means for the belt and at least one drawing gap, each of which Front of a work roll and a backup roll is formed, the work roll with its axis of rotation is so inclined to the band level that at Pulling the belt through the front of the work roll a force on the belt transverse to the belt longitudinal direction exercises.

In the invention are thus in a band in Areas of reduced thickness running in the longitudinal direction of the strip than the starting strip thickness with a continuous strip formed. This results in a comparatively high one Productivity. Also the transitions from the thicker to the thinner area gently. The width of the thinner areas can be about the diameter of the work roll and its Influence employment. That also applies to the Transition areas. Because every work roll on the material acts transversely to the tape direction in the thinned area, becomes the flow direction of the material to be displaced affected. Unlike when a groove is formed in a Band comes with a roll with a cylindrical outer surface It is therefore not too high a burden on the Material from which a tear of the tape and a ripple can result.

In order to carry out the procedure on the line effective forces not by external, acting on the tape One must see that they have to catch leadership tools Embodiment of the invention that parallel to the Strips of less thickness at the same time another Strip by pulling the tape through one of the first Drawing gap in mirror image corresponding second Drawing gap is formed, the thereby being on the tape forces exerted transversely to the longitudinal direction of the strip compensate. Depending on later use, these can Strips be completely separate or practical butt together so that you are off a single strip can go out. One possibly in the middle between these two strips can be raised compensate by re-rolling.

All you need to do is thin the strip of metal in strips to have a work roll on one side, while on the other hand a cylindrical roller as Back-up roller is used. According to an embodiment of the invention it is considered advantageous if as a backup roller another work roll is used, so that of both sides of the belt with the same to the belt level inclined work rolls forming on the belt is acted upon.

As already mentioned, the dimensioning of the Work roll in itself influence the dimensioning of the thinned strip. Can continue Influence be taken that the axis of rotation of the Work roll is tilted in different directions. Preferably the axes of the work rolls are both around an axis parallel to the longitudinal axis of the belt as well one parallel to the band plane and perpendicular to the Belt longitudinal axis tilted axis. About these There are possibilities of adjustment different areas of intervention with different Force directions. Be with neighboring work rolls whose axes of rotation towards each other and in the direction of pull Band tipped, then tensile forces occur between the two Work rolls on. Tractive forces occur between the two Work rolls even if their axes of rotation away from each other and against the direction of the tape be tilted. In contrast, step between the work rolls Compressive forces when the axes of rotation of the work rolls away from each other and tilted in the direction of pull or towards each other and against the direction of pull.

The displacement of material in the thinned Areas transversely to the direction of the tape causes with the belt held flat between the work rolls forms a wave at the band edges. To do this prevent, according to a further embodiment of the Invention provided that in the free area between the drawing slits the spreading of the tape compensating bead is molded. This bead needs not to be permanent, but can later plan again be made.

The task is further through a device with the Features of claim 5 solved.

To be effective on the device on the work rolls increasing reaction forces when molding the thinner To be able to catch strips, they support themselves after one Embodiment of the invention with their coats immediately or indirectly to each other via races. at immediate support of cylindrical or tapered Coats can slip the work rolls on each other without slipping roll off. In order to pass on as little slip as possible indirect support on the races ensure is according to an embodiment of the invention provided that several concentrically one above the other arranged and independently rotatable races support the work rolls on their tapered jackets.

As stated above, the profile is the molded areas including the geometry of the Work roll decisive. According to a preferred Embodiment of the invention instructs each work roll a tapered ring surface as the engagement surface on. With such a conical ring surface as Above all, the contact angle is the angle of inclination of the molded strip.

The device can be driven with work rolls or freely rotatable and then dragged through the belt Work rolls work.

Preferably the method is applied to warm Steel belt with a temperature of> 600 ° C. Also it will considered advantageous if the procedure is based on recrystallized annealed cold steel strip applied after forming in the forming area is heated above 600 ° C.

Figur 1

ein Band mit zwei dünneren Streifen in isometrischer Darstellung und im Schnitt,

Figur 2

ein Band mit zwei aneinanderstoßenden ausgedünnten Streifen mit zwei Arbeitswalzen in Aufsicht,

Figur 3

das Band gemäß Figur 2 im Querschnitt,

Figur 4

eine Vorrichtung zum Herstellen eines Bandes mit zwei ausgedünnten Bereichen im Querschnitt in einer ersten Ausführung,

Figur 5

die Vorrichtung zum Herstellen eines Metallbandes mit zwei ausgedünnten Bereichen im Querschnitt in einer zweiten Ausführung

und

Figur 6

verschiedene Eingriffsbereiche bei unterschiedlicher Anstellung der Arbeitswalzen der Figuren 2,4 und 5 an einem Band.

The invention is explained in more detail below on the basis of exemplary embodiments with reference to the drawing. In detail show:

Figure 1

a tape with two thinner stripes in isometric view and in section,

Figure 2

a belt with two abutting, thinned strips with two work rolls in supervision,

Figure 3

the tape according to Figure 2 in cross section,

Figure 4

a device for producing a tape with two thinned areas in cross section in a first embodiment,

Figure 5

the device for producing a metal strip with two thinned areas in cross section in a second embodiment

and

Figure 6

different areas of engagement with different employment of the work rolls of Figures 2,4 and 5 on a belt.

The devices according to Figures 4 and 5 are for Making a metal band with two in the distance thinned strips arranged from each other. For this purpose, each device has two pairs each Drawing gap 1,2 between the forming rolls 3,4,5,6. The area of engagement of these work rolls 3,4,5,6 is located on the front side and is from Tapered ring surfaces 3a, 4a, 5a, 6a are formed. The work rolls 3,4,5,6 consist of individual sections in Axis direction of decreasing diameter together, namely in particular from frustoconical sections. The Work rolls 3,4,5,6 are in a frame 7,8 Radial and axial bearings freely rotatable. While she in the exemplary embodiment in FIG. 4, only in frame 7.8 are supported, they are in the embodiment of Figure 5 additionally on idler rings 9,10,12,13 supported on each other and on one each cylindrical bearing seat 11, 14 fixed to the frame and freely rotatable are stored. A form roller 15 between the top Work rolls 3.4 is either in the frame (Figure 4) or freely rotatable on the upper outer support ring 12 stored.

Both embodiments have in common that the Work rolls with their axes of rotation 3b, 4b, 5b, 6b twice are tilted, on the one hand towards each other and to others in the direction of tension of the belt B.

Now becomes a band whose thickness is greater than the light one Height of the drawing gaps 1, 2 by the device in FIG. 4 or 5 pulled, you get a ribbon like the one in figure 1 is shown. The work rolls 3,4,5,6 with their front tapered rings 3a, 4a, 5a, 6a in the areas to be thinned out a rolling force w. The Engagement areas are shown in Figure 6. With free they are rotatably mounted work rolls 3,4,5,6 Pulling the tape along and practicing on the tape a train transverse to the direction of the train, which leads to the fact that the material practical in the areas to be thinned only flows transversely to the longitudinal axis of the strip. This effect of Flow of the material, practically only across Direction of pull, can also be done with other jobs Reach work rolls as shown in Figure 6b, c and d are shown. The only difference is that that in the employment according to Figure 6a and b between the areas to be thinned out there is tension in the employment according to Figure 6c and d between the areas to be thinned out there is compressive stress.

As the tape B is pulled through the drawing gaps 1,2 the ribbon as a whole is formed on the Belt edges next to the work rolls 3, 4, 5 a shaft that Introduces tension into the tape. This effect is the embodiments of Figures 4 and 5 thereby counteracted that by means of the forming roller 15 in the band B a bead is temporarily formed. This bead compensates for what otherwise affects the band edges Spread.

The embodiment of Figure 2 differs of those of Figures 4 and 5 only in that the Work rolls 17, 18 arranged directly next to each other are. You can then roll on each other and thus support each other. When using such employees Work rolls 17, 18 creates a band, as in Cross section is shown in Figure 3. The one at this Band slightly increased center area M can be in one subsequent rolling process can be leveled. Should for Compensating for the spread temporarily a bead in the band B can be shaped, this can be advantageous Way by means of a slide shoe, not shown here take place, which in the free gusset area between the work rolls 17, 18 is arranged.

Claims (12)

1. A method of producing a metal strip having areas of different thickness over its width, wherein at least one area of lesser thickness extending in the longitudinal direction of the strip is formed in a strip (B) of constant thickness over its width by the strip (B) being drawn through at least one drawing nip formed by an end face of a working roll and support roll, characterised in that the axis of rotation of the working roll is so adjusted at an inclination to the plane of the strip that when the strip (B) is drawn through, the end face of the working roll exerts on the strip (B) a force transversely of the longitudinal direction of the strip.
2. A method according to claim 1, characterised in that a further area parallel with the area of lesser thickness is simultaneously formed in by the strip (B) being drawn through a second drawing nip corresponding laterally inverted to the first drawing nip, the forces thus exerted on the strip compensating one another transversely of the longitudinal direction of the strip.
3. A method according to claim 1 or 2, characterised in that the support roll used is a further working roll, so that a shaping force is exerted on the strip (B) from both sides of the strip (B) by identical working rolls adjusted at an inclination to the plane of the strip.
4. A method according to claims 1 or 2, characterised in that with two drawing nips producing a widening of the strip therebetween, a bead (S) compensating said widening is formed in between the drawing nips.
5. An apparatus for producing a metal strip having areas of different thickness over its width, for the performance of the method set forth in claim 1, having guiding and pulling means for the strip (B) and at least one drawing nip (1, 2) formed by the end face of a working roll (3, 6) and a support roll, characterised in that the axis of rotation (3b, 6b) of the working roll (3, 6) is so adjusted at an inclination to the plane of the strip that when the strip (B) is drawn through, the end face of the working roll (3) exerts on the strip (B) a force transversely of the longitudinal direction of the strip.
6. An apparatus according to claim 5, characterised in that the support roll provided is a further working roll (4, 5), so that each drawing nip (1, 2) is formed by two identical working rolls (3, 4, 5, 6) adjusted at an angle to the plane of the strip.
7. An apparatus according to one of claims 5 or 6, characterised in that the axes of the working rolls are tilted both around an axis parallel with the longitudinal axis of the strip and also around an axis extending parallel with the plane of the strip and perpendicularly of the strip longitudinal axis.
8. An apparatus according to claim 7, characterised in that the generated surfaces of the working rolls (3, 4, 5, 6) bear against one another directly or indirectly via running rings (9, 10, 12, 13).
9. An apparatus according to claim 8, characterised in that when the working rolls (3, 4, 5, 6) bear directly against one another, a shaping roll (15) for forming in a bead (S) is provided between the drawing nips (1, 2) on one side of the strip.
10. An apparatus according to claims 8 or 9, characterised in that the generated surfaces of the working rolls (3, 4, 5, 6) are conical.
11. An apparatus according to claims 10, characterised in that for the direct support of the working rolls (3, 4, 5, 6), a number of running rings (9, 10, 12, 13) disposed concentrically one above the other and rotatable independently of one another support the working rolls at their conical generated surfaces.
12. An apparatus according to one of claims 6 to 11, characterised in that each working roll (3, 4, 5, 6) has on its end face associated with the drawing nip an engagement surface taking the form of a conical annular surface (3a, 4a, 5a, 6a).

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