EP1181995A2 - Device and method for forming blanks made by flexibly rolling a metal strip - Google Patents

Abstract

The blanks (1) have two sections of different thickness, with a transitional section on either side, which is to be moved to one side only. The forming surface of the tool facing the blank side to have the transitional section, has a shape to form that section, while the forming tool facing the blank side to be flat, is also flat. The forming tool has corresponding forming die (5) and mold (6), and a holding-down device (7). The appliance is esp. used for deep drawing, stretch-forming, or pressing.

Description

The invention relates to a device for forming blanks from flexible Rolled metal strip, with forming devices that are used for forming the board cooperate, the board having at least two of each other different thicknesses and the thickness profile of the board essentially runs symmetrically to the central plane of the board, i.e. the board has a thickness transition on both sides, and the thickness transitions one side of the board can be moved so that one side of the formed Circuit board has a thickness transition and the other side of the formed PCB is flat. The invention further relates to a method for forming of boards made of flexibly rolled metal strip, the board with at least there are two different thicknesses and the thickness profile the board essentially symmetrical to the center plane of the board runs, the board has a thickness transition on both sides, and the Thickness transitions are shifted to one side of the board, so that a Side of the formed plate has a thickness transition and the other Side of the formed circuit board is flat,

The circuit board in question is a workpiece that through flexible rolling of a metal strip and subsequent separation of the metal strip has been made into boards. The flexible rolling as Process for the production of metal strips with defined along their length different strip thicknesses is well known from practice and therefore characterized in that the roll gap is specifically adjusted during the rolling process becomes. Here, different lengths of tape sections with different Strip thicknesses rolled together over different pitches can be connected, the corresponding bilateral strip thickness transitions form. The goal of flexible rolling is to make rolled products with cross-sectional shapes that are optimized for load and weight. The process is usually designed as strip rolling from coil to coil.

Correspondingly, boards made from flexibly rolled metal strips point accordingly such a thickness profile that at least two of each other different thicknesses, the areas with the different from each other Thicknesses over a range having a predetermined slope, that is, a strip thickness transition, are interconnected. This Boards are generally used for the manufacture of components changing wall thicknesses used. It applies that the boards before their Further processing into components with changing wall thicknesses typically have a thickness profile that is symmetrical to the median plane of the Circuit boards is. However, the components to be made from these boards are intended often only have thickness transitions on one side. So that means e.g. at a deep-drawn part that only one inside transition or several internal thickness transitions or only an external thickness transition or several external thickness transitions are wanted, while the other side of the deep-drawn part, i.e. the outside or the Inside of the deep-drawn part, should be flat. In this respect, it is necessary that originally thickness transitions present on both sides on one side of the board to shift so that one side of the reformed board has a thickness transition and the other side of the formed board is flat.

In the prior art, the elimination of the thickness transition or Thickness transitions that are not wanted, only in a separate, additional Operation possible, either with the not yet formed sheet, in the present case before the deep-drawing process, or during the deep-drawing process achieved component, that is, after the deep-drawing process got to. In other words, in a device with a circuit board in addition to a deep-drawing process, a relocation of the original thickness transfer on both sides possible on one side of the board is two different work steps to be carried out one after the other required. This makes the device on the one hand and on the other hand the corresponding process is complex and expensive.

It is the object of the invention, such a device or such Process for forming a circuit board from a flexible rolled metal strip to indicate with or with the workpieces present as blanks with a substantially symmetrical to the median plane of the board running thickness profile in a single operation the originally thickness transitions present on both sides can be shifted to one side of the board are so that the one side of the formed plate has a thickness transition and the other side of the formed board is flat.

The inventive device for forming blanks from flexible rolled metal strip in which the previously derived and shown task is initially and essentially characterized by that the forming surface of the forming device facing the circuit board side is a thickness transition in the deformed state of the board should have a shape adapted to the thickness transition to be achieved has, and the forming surface of the forming device, that of the board side facing, which should be flat in the deformed state of the board, is flat.

The two sides of the manufactured by flexible rolling of a metal strip The board is thus changed during the forming process in such a way that the original thickness transitions present on both sides in the same work step as the deformation is shifted on one side. That means that with the reshaped Workpiece, i.e. the formed blank, only a change in thickness exists on one side while the other side is flat, this being Thickness transition is larger, namely is generally twice as large as in not yet deformed condition of the board. When it has been said that after forming one side of the workpiece is flat, it is not meant that this page is entirely in one level. Much more all that is meant is that there is no longer a thickness transition on this side. However, it is particularly so when. B. the workpiece in one Thermoforming process has been formed into a deep-drawn part, of course, in such a way that the flat side of the formed workpiece does not change more entirely located in one level, but from the original one Side of the board protrudes corresponding level, since it is one Deep-drawn part is generally a three-dimensional structure. insofar So here is the term "plan" as a contrast to the state to understand one side of the workpiece in which this side a Has thickness transition.

The forming device is basically for all known forming processes usable, with the help of which sheets are formed. Is accordingly the invention also applies to all conventional types of forming devices applicable. According to a preferred development of the invention, however provided that the forming devices a stamp and a die comprise, which cooperate to form the workpiece. Such a Stamp and such a matrix act to reshape the Workpiece generally together such that a frame from the die is formed with an opening enclosed by the frame, wherein the workpiece to be formed, i.e. the flexibly rolled blank, on the Frame rests, so that with the stamp of the opening of the die lying area of the board by plastic deformation of the same in the Opening of the die can be pressed. Such a combination from a stamp and a die z. B. for the deep-drawing process used.

Basically are for the implementation of a forming process in question two forming devices, such as. B. a stamp and a Die, sufficient. According to a preferred development of the invention however, it is provided that the forming devices also have a Hold down hold-down and the hold-down one adapted to the thickness transition Has shape when it is provided on the side of the workpiece, which should have a thickness transition in the deformed state, and flat is, if it is provided on the side of the workpiece, that in the formed The condition of the workpiece should be flat. This applies exactly to the hold-down device what for the other forming devices, e.g. B. the stamp and the matrix also applies, namely because of its either to be achieved Thickness transition adapted or plan during the shape Forming process a relocation of the originally existing on both sides Thickness transitions on one side is achieved.

In the preferred embodiment of the invention, in which a stamp and a die are provided as forming devices, the hold-down device preferably on the side of the board corresponding to the stamp arranged so that the holding-down device for holding down the workpiece the matrix can work together. Specifically, this means that through the Interaction of the hold-down with the die between the workpiece the hold-down device and the die is clamped. That way especially with only slightly stiff workpieces ensured that when pressing the punch into the opening of the die the workpiece does not slide completely into the opening of the die.

It has always been stated beforehand that the shaping device or the shaping devices, more precisely: the corresponding forming surface or the corresponding ones Forming surfaces facing the side of the workpiece or are a thickness transition in the deformed state of the workpiece should have a shape adapted to the thickness transition or have. Such a matched to the thickness transition to be achieved The shape of the forming surface of a forming device is generally then when the course of the forming surface of the forming device exactly the course of the surface of the formed workpiece to be achieved equivalent. This means that the surface of the formed workpiece receives exactly the shape given by the shape of the forming surface of the forming device is specified. Especially when there are compression effects or hysteresis effects can, however, at least from this rule slightly deviated. For the exact dimensioning the forming surface of a forming device, which faces the side of the workpiece is a sheet thickness transition in the deformed state of the workpiece should generally have that on the board Originally existing mutual thickness transitions by one Thickness d the forming surface of the forming device has a thickness transition of essentially a thickness of 2d.

According to the invention, one of the devices described above is used preferably for a high pressure sheet metal forming process, a tensile forming process or a tensile pressure forming process, in particular for deep drawing, stretching or pressing. regardless of course, such a device according to the invention is also for everyone other forming processes suitable with two cooperating forming devices work.

The inventive method for forming blanks from flexible rolled metal strip, in which the derived and shown above The problem is solved is initially and essentially characterized by that the thickness transitions in the process step to one side of the board be shifted, in which the forming of the board takes place. In particular this is possible because the shift in thickness transitions on one side of the board and reshaping the board with the same Forming devices are carried out. Other preferred developments of the invention Procedures result in analogy to those previously described preferred embodiments of the invention Contraption.

Fig. 1

eine durch flexibles Walzen eines Metallbandes und anschliessendes Vereinzeln hergestellte Platine mit beidseitigen Dickenübergängen, in einer perspektivischen Ansicht,

Fig. 2A

schematisch, die wesentlichen Bauteile einer Vorrichtung zum Herstellen eines Tiefziehteils mit innen liegendem Dickenübergang gemäß einem ersten bevorzugten Ausführungsbeispiel der Erfindung, einerseits im Längsschnitt, andererseits im Querschnitt,

Fig. 2B

ein mit der schematisch aus Fig. 2A ersichtlichen Vorrichtung hergestelltes Tiefziehteil mit innen liegendem Dickenübergang,

Fig. 3A

schematisch, die wesentlichen Bauteile einer Vorrichtung zur Herstellung eines Tiefziehteils mit außen liegendem Dickenübergang gemäß einem zweiten bevorzugten Ausführungsbeispiel der Erfindung, einerseits im Längsschnitt, andererseits im Querschnitt, und

Fig. 3B

ein mit der schematisch aus Fig. 3A ersichtlichen Vorrichtung hergestelltes Tiefziehteil mit außen liegendem Dickenübergang.

In particular, there are now a multitude of possibilities for designing and developing the device according to the invention and the method according to the invention. For this purpose, reference is made on the one hand to the claims subordinate to the independent claims and on the other hand to the following detailed description of preferred exemplary embodiments of the invention with reference to the drawing. In the drawing shows

Fig. 1

a perspective view of a circuit board produced by flexible rolling of a metal strip and subsequent singling with thickness transitions on both sides,

Figure 2A

schematically, the essential components of a device for producing a deep-drawn part with an internal thickness transition according to a first preferred embodiment of the invention, on the one hand in longitudinal section, on the other hand in cross section,

Figure 2B

FIG. 2 shows a deep-drawn part with the internal thickness transition produced using the device shown schematically in FIG. 2A,

Figure 3A

schematically, the essential components of a device for producing a deep-drawn part with an external thickness transition according to a second preferred embodiment of the invention, on the one hand in longitudinal section, on the other hand in cross section, and

Figure 3B

a deep-drawn part produced with the device schematically shown in FIG. 3A with an external thickness transition.

From Fig. 1 is a perspective view through flexible rolling of a metal strip and subsequent separation of the board 1 obtained, the two different areas, namely one area 2 and a region 3, with different thicknesses. The Area 2 is from area 3 on both sides of the circuit board 1 by one Thickness transition 4 separated, the transition with a predetermined slope from the thickness of area 2 to the thickness of area 3.

A device for forming a circuit board according to FIG. 1 after a first preferred embodiment of the invention is schematic from Fig. 2A can be seen, with a longitudinal section above and a cross section shown below are. In the devices shown in FIG. 2A, as in the 3A apparent device, applies that only such components are shown are essential to the invention. That means that Components of the devices are not shown, in the same way in conventional devices for forming workpieces Sheet are provided.

The device according to the first preferred embodiment of the invention has a stamp 5 and a die 6, between which the to be formed circuit board 1 is arranged. To the board 1 for the forming process to hold, a hold-down 7 is also provided, with the help of which the board 1 can be fixed on the die 6. Through this fixation it is ensured that the board 1 is not complete during the forming process slips into the opening of the die 6.

As can be seen from FIG. 2A, the circuit board 1 has two regions 2, 3 with one another different thicknesses, the thickness profile of the board 1 symmetrical to the central plane of the board 1. With the one shown in FIG. 2A Such a component, namely a deep-drawn part, is now to be achieved by the device, that only includes an internal thickness transition 4, on his However, the outside has completely flat surfaces. For this purpose, the die 6 formed such that its surface on which the board 1 during the forming process rests, ie the forming surface of the die 6, completely in one Level lies. The opening formed by the die 6 follows - apart from the rounded corners - essentially a rectangular shape. in the In contrast, the forming surfaces of the punch 5 or the hold-down have 7 each have such a shape that the thickness transition to be achieved 4 of the board 1 are adapted. This means that the forming surface, the rests on the board 1 during the forming process, just not completely in one level. Instead, it is provided that the thickness of the hold-down 7 in the area that rests on the thinner area 3 of the circuit board 1, is thicker than in the other area, the thicker area 2 of the board 1 is assigned. However, such an adjustment of the thickness of the Hold-down 7 provided on the shape of the board 1, which is the thickness transition 4 corresponds to that which is present in the not yet formed sheet 1, 'but such an adjustment of the thickness of the hold-down 7, which the deformed plate 1 corresponds to the thickness transition 4 to be achieved. insofar is the difference in thickness between the thick area of the hold-down 7 and the thin area of the hold-down 7 is essentially twice as large like the one-sided height difference of the thick area 2 to the thin one Area 3 of the circuit board 1. In other words, the hold-down 7 is in its thin area just thinner than its thick area Area that is the difference in thickness between the thick area 2 and the corresponds to thin area 3 of the circuit board 1. This takes into account the fact that during the forming process of the board 1 at the same time that originally on both sides present thickness transition 4 to one side, in the present case the inside, of the deep-drawn part is relocated. The same applies in principle to the Stamp 5, the forming surface also to the thickness transition to be achieved 4 is adjusted. It also changes, as from that in Fig. 2A Cross-sectional view shown can also be seen in the stamp 5 Width in the longitudinal direction. Accordingly, is in the opening of the die 6 inserted punch 5 the distance between the punch 5 and the die 6 in the areas where the stamp 5 has a greater width Longitudinal direction, less than in the areas where the stamp 5 has a smaller width in the longitudinal direction. This bigger space between the punch 5 on the one hand and the die 6 on the other hand, it is necessary because this space in the forming process, which also the thickness transition 4 originally present on both sides to the inside of the formed circuit board 1, the thicker area 2 of the circuit board 1 must record.

From Fig. 2B, finally, a formed circuit board 1 can be seen, which with the 2A schematically illustrated device according to the first preferred Embodiment of the invention has been made. Out 2B that the outer surfaces of the formed circuit board 1 are complete are flat, while the inner surfaces of the formed circuit board 1 Have thickness transition 4, with a thicker area 2 of the board connects a thinner area 3 of the circuit board 1.

3A schematically shows a device according to a second preferred Embodiment of the invention can be seen with a reshaping a board 1 is possible in such a way that an external one Thickness transition 4 can be achieved and the inner surfaces of the deformed Circuit board are completely flat, as can be seen from Fig. 3B. Since now according to the second preferred embodiment of the invention in the Circuit board 1, thickness transitions 4 originally present on both sides should be shifted that only on the lower side of the board 1 Thickness transition 4 is present, it is provided that during the forming process on the circuit board 1 surface of the hold-down 7, that is Forming surface, as well as the surface of the Stamp 5, ie the forming surface of the stamp 5, each completely in one Level. In contrast to this, with regard to the forming surface of the die 6, on which the circuit board 1 rests during the forming process, that this is not completely in one plane, but one on that Achieving thickness transition 4 has an adapted shape. In this respect, too provided that - again with the exception of the rounded corners - the Stamp 5 has a substantially rectangular shape, while the in the opening 6 formed in a first area has a greater width has in the longitudinal direction than in a second region, the first region the thin area 3 of the circuit board 1 and the second area the thick Area 2 of the board 1 is assigned. A corresponding form of the matrix 6 is necessary because as a forming surface in the die 6 when pressing the Circuit board 1 in the opening of the die 6 also delimiting this opening Inner surface of the die 6 acts. The mode of operation of that from FIG. 3A schematically apparent device according to the second preferred embodiment the invention is analogous to that with the device to be carried out according to the first preferred embodiment of the invention Method.

The invention is in connection with the two preferred exemplary embodiments the invention has been explained using a deep-drawing process, this limits the use of the device according to the invention but not on such a method, so that the device according to the invention also for other forming processes, such as for high-pressure sheet metal forming processes or Zugdruckformformverfahren, can be used.

Claims (11)

Device for reshaping blanks from flexibly rolled metal strip, with reshaping devices which cooperate to reshape the blank, the blank (1) having at least two different thicknesses and the thickness profile of the blank (1) essentially symmetrical to the central plane of the blank (1 ) runs, the board (1) thus has a thickness transition (4) on both sides, and the thickness transitions (4) can be shifted to one side of the board (1), so that one side of the formed board (1) has a thickness transition (4) and the other side of the formed plate (1) is flat, characterized in that the forming surface of the forming device, which faces the side of the plate, which in the deformed state of the plate (1) should have a thickness transition (4), one to be achieved Has thickness transition (4) adapted shape, and the forming surface of the forming device, which faces the circuit board side, which in the deformed state of the Circuit board (1) should be flat, is flat. Device according to claim 1, characterized in that the shaping devices comprise a punch (5) and a die (6) which cooperate for shaping the blank (1). Apparatus according to claim 1 or 2, characterized in that the shaping devices comprise a hold-down device (7) and the hold-down device (7) has a shape adapted to the thickness transition (4) if it is provided on the side of the blank which is in the deformed state of the blank (1) should have a thickness transition (4), and is flat if it is provided on the circuit board side, which is to be flat in the deformed state of the circuit board (1). Apparatus according to claims 2 and 3, characterized in that the hold-down device (7) is provided on the side of the plate (1) corresponding to the stamp (5) and cooperates with the die (6) to hold down the plate (1). Use of a device according to one of claims 1 to 4 for a High pressure sheet metal forming process, a tensile forming process or a tensile pressure forming process, especially for deep drawing, stretch drawing or a press. Process for forming blanks from flexibly rolled metal strip, the blanks being at least two different thicknesses and the thickness profile of the blanks being essentially symmetrical to the central plane of the blanks, i.e. the blanks having a thickness transition on both sides, and the thickness transitions on one side of the plate are displaced so that one side of the formed plate has a thickness transition and the other side of the formed plate is flat, characterized in that the thickness transitions in the process step are shifted to one side of the plate in which the forming of the plate also takes place. Method according to Claim 6, characterized in that forming devices are provided and the thickness transitions are shifted to one side of the plate and the plate is formed using the same forming devices. Method according to Claim 7, characterized in that a shaping device is provided which faces the blank side, which in the deformed state of the blank is to have a thickness transition, and a second shaping device is provided which faces the blank side, which in the deformed state of the blank should be flat, the forming surface of the forming device, which faces the circuit board side, which should have a thickness transition in the formed state of the circuit board, has a shape adapted to the thickness transition to be achieved, and the forming surface of the forming device, which faces the circuit board side, the should be flat in the deformed state of the board, is flat. Method according to claim 7 or 8, characterized in that the shaping devices comprise a punch and a die, which cooperate for shaping the blank. Method according to one of claims 7 to 9, characterized in that the forming devices comprise a hold-down device and the hold-down device has a shape adapted to the thickness transition if it is provided on the blank side, which is to have a thickness transition in the formed state, and is flat, if it is provided on the side of the board that should be flat in the deformed state of the board. Method according to claims 9 and 10, characterized in that the holding-down device is provided on the side of the board corresponding to the stamp and cooperates with the die to hold down the board.

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