DE10303458A1 - Shaping method for thin metal sheet, involves finishing rough forming body to product shape using tool that moves three-dimensionally with mold punch as mold surface sandwiching sheet thickness while mold punch is kept under pushed state - Google Patents

Abstract

The method involves shaping a rough forming body from a thin metal sheet using a mold punch (4). Afterwards, the rough forming body is finished to a product shape by use of a tool (8) capable of moving three-dimensionally with a mold punch as a mold surface from an opposite side to the mold punch sandwiching the sheet thickness while the mold punch is kept under a pushed state. The mold punch is pushed while the edge portions of the thin metal sheet are clamped, from below a sheet thickness direction. An independent claim is also included for a molding apparatus for thin metal sheet.

Description

technical area

The invention relates to a method for forming a thin one Sheet metal and a device for performing the method.

State of technology

Methods and devices for processing a thin metal sheet into a 3-dimensional shape are, for example, in US Pat JP-A-7-132329 described. In this known technique, edge parts of a thin sheet of metal are attached to a frame-shaped table that can move up and down, and a rod-shaped pressure body is inserted within a space enclosed by the frame-shaped table. In order to carry out the forming, this pressure body is brought into contact with the underside of the thin metal sheet, and a rod-shaped tool which can move in a Z direction is positioned on the top of the thin metal sheet. While the rod-shaped tool is now being moved around the pressure body, the frame-shaped table is lowered so that the thin metal sheet is gradually plastically deformed.

This deformation process will considered suitable for the production of a test product. Because the rod-shaped Tool describes a contour line in circular form to successively To form the shape of the end product, this process is from Beginning to the end of the shaping, however, very time consuming, and mass production of 500 pieces per month is in practice difficult to reach.

Although this molding process is a simple expanding shape like a cone or a pyramid allowed to shape easily, it is subject to the restriction of one angular Section on a long wall not being able to shape easily nor a product with grooves and protrusions in a large floor area easy to shape.

Since the known technology on a Stretch forming is based exclusively on material stretching used as a processing principle, the resulting product falls in terms of compared to its layer thickness and its dimensional accuracy Molding products received significantly. Therefore, is suitable this procedure less for a trial production for the mass production of molded products and for manufacturing of trial products.

description the invention

To solve the above Problems is a first object of the invention to provide a molding process, which exactly and beyond 3-dimensional in a short time Products such as trial products for mass production of molded articles from a thin Metal sheet without restriction the shape can shape.

A second object of the invention consists in creating a device that works exactly and beyond in a short time 3-dimensional products such as trial products for mass production Shape molded products without limiting the shape can and is of simple construction.

A molding process for a thin sheet of metal to the solution The first task described above comprises the steps: Pinching edge parts of a thin metal sheet, pressing one Form stamp of the shape of the product from below towards the sheet thickness in this clamping state, carrying out a shaping process to form a coarse molded body with Top and side sections, and fine shaping of the coarse shaped body a product shape using a 3-dimensional movable Tool, wherein the die as a molding surface of the opposite Side forms a sandwich with the sheet thickness while being pressed is held.

The step of fine shaping the coarse shaped body End product form can use a process which is a rod-shaped tool used and the coarse shaped body undergoes a local plastic deformation. Furthermore is it possible to use an elastic tool in a first stage and this one of the stamps forming a sandwich with the sheet thickness opposite Side against the form stamp so that you have a local Compression set, and fine forming in a second stage using the rod-shaped Tool. in this connection you can carry out a highly precise shaping, even with complicated ones Shape with local projections and recesses.

To achieve the second object, the invention provides a shaping device for a thin metal sheet, which has a bed provided with a mounting frame, and also a plurality of bending brackets which are arranged on the bed at mutual distances in order to clamp edge parts of the thin metal sheet in the sheet thickness direction, as well as a form punch which is arranged within a recessed chamber which is formed in the bed further inside than the bending brackets, a form punch lifting drive which presses the form punch into the thin metal sheet held by the bending brackets, and a second shaping device which in three axial directions is movably attached to the mounting frame, and finally a tool attached to the second shaping device for shaping a coarse shaped body formed by the form stamp in cooperation with the form stamp.

With this construction, a Prepared stamps corresponding to the shape of the product and on the die jack actuator attached, and then a highly accurate shaping can be performed.

The bending brackets are on the Bed arranged and do not move up and down. With in other words unlike known shaping devices, there is no up and down movable frame-shaped Table for clamping the edge parts of the thin metal sheet in the direction the sheet thickness. The invention does not require a mechanism to lower the frame-shaped Tables according to the progress of shaping, still a compensation movement control. Therefore the construction of the device can be kept simpler. Moreover can the height the device, and the introduction of the thin metal sheet as well as the removal of the product can be in a position close to the height of the floor be made.

The invention is suitable for molding greater objects such as body panels as automotive parts, such as fenders or Hood, aircraft parts, building parts, Kitchen appliances, bathroom items and electrical Equipment.

Other features and advantages of Invention emerge from the following detailed description, however, the invention is particularly not in construction of these designs limited, as long as it fulfills its basic characteristics are. It is therefore understood that the person skilled in the art will make various changes and can make modifications without departing from the scope of the invention leave.

Short description of the drawings

1 shows a side section of an embodiment of a sheet metal forming device according to the invention before the start of forming a thin metal sheet;

2 shows a side section through the device according to the invention to illustrate a working phase when using the device;

3 shows a top view;

4 is a sectional front view;

5 Fig. 4 is a side elevation, partly in section, of the arrangement of a tool for fine molding a product and a second molding device;

6 Fig. 4 is an enlarged partial side view illustrating a working phase in molding using a first type of tool to fine-shape the product into its shape;

7 an enlarged partial section illustrating a phase of shaping using a second type of tool for fine shaping the product into its shape;

8th a partial perspective view of another example of a second deformation device according to the invention;

9 a partial sectional view 8th ;

10A . B and C Examples of molding tools;

11A and 11B Views of examples of a final shaping device;

12A to 12D Sectional views of sections of a deformation example according to the invention;

13A to 13C Partial sections to illustrate the molding steps in another example according to the invention;

14A and 14B Partial sections to illustrate the step-by-step processing in a further shaping example according to the invention;

15 a perspective view of an example of a product made according to the invention;

16 a perspective view of another example of a product made according to the invention;

17A to 17C Partial cuts, which the processing steps in the shaping of in 16 illustrate the product shown.

detailed Description of the invention

Below are explanations the invention with reference to the accompanying drawings.

The 1 to 4 show a forming device for a thin metal sheet according to a first embodiment of the invention.

The reference number 1 denotes a bed or a frame (hereinafter referred to as "bed"). In the middle area is a recessed chamber 11 that go to the top 10 opens, trained. A linear actuator 2 , such as a hydraulic cylinder, is fixed in the lower part of the chamber 1 accommodated. With an outer part of the linear actuator 2 is a form assembly washer 3 connected to a form stamp 4 is removably attached, which is machined in a 3-dimensional shape corresponding to the shape of a product.

The form stamp 4 generally represents those form stamps, which are referred to as "shaped type" or as "master form" and have an upper section and side sections. The form stamp 4 is generally made of metal, such as steel, but may also be made of FRP (fiber reinforced plastic) in some cases. The form stamp 4 has a concave-convex area in addition to a smooth surface shape 40 , which can be a projection, a recess, a recess, a groove, etc.

The reference number 5 denotes a plurality of bending brackets, which are arranged at a predetermined distance from each other so that they open the chamber 11 surrounded on the bed outside this chamber. Any bending bracket 5 contains a cheek 50 to support an edge part of a thin sheet W, one of the cheek 50 opposite holding disc 51 , a block-shaped main body 5a with one on the holding disc 51 pressing bracket drive 52 , and a motion drive 5b that is on the back of the main body 5a is attached to the bed and one with the main body 5a connected end part, as in 6 you can see. The bending brackets 5 can work separately. Their number and their working methods (the bracket drive 52 can be used alone or together with the motor drive 5b work) are selected according to the shape of the thin sheet, its mechanical properties and the shape to be formed.

With the reference number 6 is referred to as a second or secondary shaping device that is located above the bed 1 can move. It contains a mounting frame 6a who's on the bed 1 is appropriate that he the bending brackets 5 is not in the way, and on which a main shaft body 6 is mounted. The main shaft body 6b has a tool holder 6c on which a tool 7 for local compression deformation and a shaping tool 8th are movably attached, as will be explained later.

The mounting frame 6a has four or more columns 69 with their lower parts on the bed 1 are attached, also a pair of parallel X-axis rails 60 by the upper parts of this pillar 69 crossways, and a pair of Y-axis rails 61 which of the X axis rails 60 and 60 be worn. A numerically controlled drive mechanism 62 is on the Y axis rails 61 mounted to this along the X axis rails 60 . 60 to move.

The main shaft body 6b sits on the Y-axis rail 61 and has a numerically controlled drive mechanism 63 for its movement along the X-axis rail 61 , The main shaft body 6b carries a tool holder on its lower part 6c that protrudes towards the bed. A numerically controlled drive mechanism 64 for moving the tool holder 6c or a carriage carrying it in the Z-axis direction is on the upper part of the main shaft body 6b assembled. The drive mechanisms 62 . 63 and 64 are electrically connected to a controller, not shown, and can be removed from the position of the tool holder 6c attached tool according to the control signal coming from the control.

The tool holder 6c has any clamping mechanism. In this embodiment there is an extendable tensioning device 600 provided a mounting nut 601 and a slotted sleeve 602 has, which in a conical hole of the clamping device 600 fits how 5 shows.

With the reference number 7 is the tool for local compression molding. The tool 7 has a fitting part 70 for the sleeve 602 of the tool holder 6c and an elastomer part 71 , such as urethane rubber, for the local application of a strong pressure on the thin metal sheet W, in cooperation with the concave-convex area 40 of the form stamp 4 to deform as from the 4 and 5 evident.

With the reference number 8th is a molding tool made of a hard material, such as a super hard compound. The tool 8th has a fitting part 80 for the sleeve 602 of the tool holder 6c and a push part 81 for the shaping of detailed shapes of the thin metal sheet W and fine shaping of the workpiece as a whole in cooperation with the die 4 , as in 5 you can see. The fitting parts 70 and 80 both tools 7 and 8th have the same outside diameter.

The construction shown in the drawings is just an example of the invention represents it can other constructions are also used.

Although the embodiment shown here uses an AC servo motor to drive the secondary deforming device 6 used, a linear motor can be used instead, like the one 8th and 9 demonstrate. The reference number 65 denotes a guide rail, the reference number 66 a magnetic disk, the reference number 67 a bobbin carriage and the reference number 68 a linear scale.

The shaping tool 8th can have a spherical pressure section at its end 81 have how 10A shows. According to 10B alternatively, it can be at the free end of a recess 82 with a curvature in which a hard ball 81 ' rotates. As a further alternative, one with the recess 82 communicating liquid supply opening 83 be provided for the supply of a lubricant, such as 10C shows.

The shaping tool 8th can opposite the tool holder 6c be rotatable. 11A shows this example. On the lower part of the tool holder 6c sits a rotatable shaft 6d on which the tool 8th eccentric to the axis of the rotatable shaft 6d sitting. Any rotating device can be used, but in this example is a drive motor 6e on the tool holder 6c mounted, and the motor rotation is via a transmission element 6f , such as a belt or a gearbox, on the rotatable shaft 6d transfer.

Next is a molding process for a thin Sheet metal according to the invention explained.

In order to start the deformation, the shaped stamp is provided with the shape 4 on the mold assembly disc 3 fixed with the help of screws and nut. After this preparation, the thin ne sheet metal W with the help of a conveyor, such as a magnetic clamping device on the bed 1 brought. In this case, it is preferable that the motion drive 5b the bending bracket 5 has been operated so that it is the main body 5a moved back, and that the holding washer 51 through every bracket drive 52 the bending bracket 5 has been moved to the open position. Then the main body 5a moved forward, the thin metal sheet W is transported and its edge regions between the main body 5a and the cheek 50 is introduced. The required bracket drive 52 is used to lower the holding disc 51 actuated to the edge areas of the thin metal sheet W against the cheek 50 to pinch.

1 and 12A show this state. The thin metal sheet W is over the recessed chamber 11 spread, and the form stamp 4 is located below the thin metal sheet W. The second molding device 6 is in the page ready position. The tool fits according to the shape of the product 7 for local compression molding or the molding tool 8th at that time in the tool holder 6c , If this has a relatively simple shape, such as a shape with no concave-convexity on its top, then the tool can 8th used for molding. Otherwise the tool 7 used for local compression for the first stage of the deformation process.

Next is the linear actuator 2 actuated to the die 4 to raise. The form stamp 4 is pressed into contact with the underside of the thin metal sheet W, and when the die 4 moves upward at the same time, then the thin metal sheet W undergoes plastic deformation in the direction of the sheet thickness via the shape of the die 4 subjected and is roughly deformed into a 3-dimensional shape with upper and side wall parts by the squeezing process. The symbol W1 denotes a roughly shaped body.

The pressure force of the bracket drive 52 the required bending bracket 5 is reduced during rough shaping according to the properties such as shape, sheet thickness and elongation of the thin metal sheet W, of the material in order to support the flow of the material. If this is not enough, the movement drive 5b put into action the main body 5a vorzubewegen. This prevents the material from tearing and the overall shape, with the exception of the molded local area 40 (in this case a bulge) shaped like 12B shows.

Next is the form stamp 4 held in the raised position, the tool 7 for the local compression set is immediately above the local compression set 40 emotional. This position can be adjusted by moving the Y-axis rail 61 opposite the x-axis rails 60 with the help of the drive mechanism 62 and by moving the main shaft body 6b opposite the Y-axis rail 61 through the drive mechanism 63 to reach.

After that, the tool 7 for the local compression set immediately above the local compression set 40 with the help of the drive device 64 moved in the Z direction. The part WP that has not yet been processed, which so far is the local compression area 40 had not yet been touched, brought into contact with it and suffered a compression set when the elastomer 71 against the area 40 is pressed so that it creates a profile, such as 12C shows. The symbol WP1 denotes the compression-molded part.

After that, the main shaft body 6b moved sideways, the clamping device relaxed and the tool for local compression deformation is removed from the tool holder 6c removed and through the forming tool 8th replaced.

The main shaft body 6b is then driven by the appropriate drives 62 . 63 and 64 moved in the X, Y and Z axis directions, and the printing part 81 ( 81 ' ) of the tool 8th for the final forming, there is strong pressure contact with the pressure forming part WP1 in the area of the local pressure deformation area 40 brought to cause a local plastic deformation. In this way, the exact shape of the details can be shaped as it is 12D shows. The symbol WP2 denotes a finished local area. If the main shaft body 6b through the appropriate drives 62 . 63 and 64 parts in the X, Y, and Z axis directions can also have parts other than the local compression area 40 how the side walls and the boundary part between the side wall and ceiling are finished into the final profile.

In the first step of the invention, the thin metal sheet W is free deformation including the squeeze component by using the die 4 been suspended. Therefore, the molding tool is not necessary 8th to move in the contour circle in the second step. In other words, a shaping can also be carried out while the thin metal sheet W is moved in three dimensions in accordance with the shape of the product, it being continuously on the die 4 is pressed.

When the shaping is finished as described above, the main shaft body becomes 6b from the drive mechanisms 62 . 63 and 64 moved into a lateral rest position, and the form stamp 4 is brought into its lower end position. Then the form stamp 4 removed from product W2 and this remains, taking it from the flex brackets 5 is held. Their clamping effect is then released and the product W2 can then be removed.

The 13A to 13C show another example of local compression set and final Shaping. The form stamp 4 has a recessed local area (recess or groove) 40 and also a protrusion 400 at the bottom of the local part.

In this case the tool 7 for the local compression deformation at least moved in the Z-axis direction or in order in the X-axis direction and / or in the Y-axis direction and then in the Z direction, while the rough deformation using the die 4 is carried out as 13A shows. If this operation is carried out at least once, the undeformed part WP will be under strong pressure in the recessed local area 40 pushed in when the elastomer 71 strongly presses how 13B shows. At this time, the compression set part WP1 is from the strong pressure of the elastomer 71 not yet sufficiently in contact with the excluded local area 40 has been brought. Hence the tool 8th for the final shaping under numerical control moved one after the other, the pressure deformation part WP1 firmly in contact with the bottom projection 400 to bring how 13C shows. This enables high-precision shaping to be carried out.

The 14A and 14B show the case where the form stamp 4 a convex local area (protrusion) 40 and also a recess at the top 401 Has. In this case, the not yet deformed part WP of the roughly shaped body W1 is a local pressure molding using the tool 7 subjected to local compression deformation, such as 14A shows, and there is a touching movement of the molding tool 8th for shaping details and finishing. In this way, high-precision molding can be carried out.

You use it as a tool 8th a hard ball for fine shaping 81 ' that can turn freely like it 10B shows, then the contact with the material changes from a sliding contact to a rolling contact. This makes it possible to prevent heat from being generated by friction, to reduce the occurrence of machining scratches on the molded article, and to avoid springback.

If the tool 8th is rotatable for the final shape, as in 11A is shown, the molding accuracy can be improved because eccentric pressure can also be exerted on the deformation area, as is the case 11B shows.

• 1. Das erfindungsgemäße Verfahren enthält den Schritt der Betätigung nur eines Teils der Mehrzahl von Biegehalterungen 5, um ein lokales Fixieren und Festklemmen vorzunehmen. Mit anderen Worten umfasst das Verfahren den Schritt, die Druckkraft der Halterungsantriebe 52 der erforderlichen Biegehalterungen 5 nicht freizugeben, oder die Druckkraft der Halterungsantriebe 52 der Biegehalterungen 5 freizugeben.
• 2. Wenn die auszubildende Form glatt ist, wie etwa eine Haube, dann ist es möglich, den örtlichen Druckformgebungsschritt wegzulassen und eine Formfixierung zur Ausschaltung eines Zurückspringens durch Berührungsbewegung seitens des Formungswerkzeugs 8 nach dem Grobformen vorzunehmen, oder ein Formen der feinen Teile und eine Endformgebung vorzunehmen.

The method according to the invention can take on various forms of use.

• 1. The method according to the invention includes the step of actuating only a part of the plurality of bending brackets 5 to locally fix and clamp. In other words, the method comprises the step, the pressure force of the holder drives 52 the required bending brackets 5 not to release, or the pressure force of the bracket drives 52 of the bending brackets 5 release.
• 2. If the shape to be formed is smooth, such as a hood, then it is possible to omit the local pressure molding step and a shape fixation to eliminate a snap back by touching the molding tool 8th after the rough shaping, or a shaping of the fine parts and a final shaping.

The invention is also suitable for trial production of various large 3-dimensional products. For example, outer surfaces of automobiles, such as fenders or hood parts such as it, can be produced simply and precisely with the invention 15 shows or a hood inner sheet according 16 ,

There are still more detailed explanations. This in 16 The product shown has a size of 885 × 970 mm and contains side walls WS and a top wall WT, which is connected at right angles to the side walls WS. Furthermore, the top wall WT has a complicated shape with a plurality of groove-shaped recessed parts WP2. The groove-shaped recessed part WP2 has a base width of 20 mm, an opening width of 32 mm and a depth of 13 mm.

To form such a product, the invention uses a die 4 with grooved local areas 40 corresponding to the groove-shaped recessed areas WP2, such as 17A shows and presses the stamp 4 into the thin metal sheet to freely shape the raw molded body W1. Next, the undeformed part WP of the coarse shaped body W1 is subjected to a local compression deformation, whereby the tool 7 for local printing forms in strong pressure contact with the local area 40 brought like it 17B shows. The shaping tool 8th is then used to make the tool 7 to replace for local compression set. The tool 8th is moved while it is in contact with the local area 40 remains according to the final shaping 17C perform. In the rough shaping state, the side walls WS are not yet in close contact with the side surface 41 of the form stamp, but are still free. If the tool 8th Is moved 3-dimensionally and the side walls WS to the side surface 41 of the die, but sharp side walls can be formed.

The deformation conditions used in practice are as follows:
The thin metal sheet is an SPCD-coated steel sheet with a sheet thickness of 0.7 mm and a size of 1.050 × 1.130 mm. For the rough forming, an angle holding force of 70 tons (tonf) and an oil are used as a lubricant. As an elastic tool, urethane rubber with a Cross section of 50 mm x 70 mm is used and local pressure under a pressure condition of 20% compression is used.

As a rod-shaped tool, it becomes a super hard one Alloy with a diameter of 10 mm used, and the final shaping takes place under the movement condition (shaping dimension (pitch) in the height direction) of 0.5 mm.

The deformation time is 2 hours, and the accuracy of the product obtained is ± 0.5 mm, with which the required quality is satisfied becomes. The sheet thickness reduction ratio is within 20 %.

industrial application

The invention is suitable for trial production numerous great 3-dimensional products.

Claims (5)

Shaping process for a thin metal sheet with the steps: - Pinching from marginal areas of a thin Metal sheet; - Press one Form stamp that has received the shape of a product in this Condition from below in the direction of the sheet thickness; - performing the Shaping for shaping a coarse shaped body with an upper part and with side parts; and - finishing of the coarse shaped body to a product form by using a three-dimensionally movable Tool with the form stamp as the surface of the form of the form stamp opposite Side which while he in the pressed Condition is maintained, a sandwich configuration with the sheet thickness forms. Shaping process for a thin metal sheet according to claim 1, in which the step of finishing to product shape under Use a rod-shaped Tool performed is, the coarse shaped body undergoes a local plastic deformation. Shaping process for a thin metal sheet according to claim 1, in which the step of finishing to the product shape in two stages is performed using an elastic tool that of the opposite Side against the one that forms a sandwich structure with the sheet thickness Form stamp pressed is used to cause local compression deformation and the coarse shaped body under Use of the rod-shaped tool to shape into a final shape. Forming device for a thin sheet of metal with - one bed provided with a mounting frame; - a plurality of bending brackets, which are spaced apart on the bed and edge parts of the thin Clamp the sheet in the sheet thickness direction; - a form stamp that is inside a recessed chamber, which sits in the bed inside the Bending brackets is formed; - a lifting drive for the die, around this in the thin metal sheet held by the bending brackets to press; - one secondary molding device attached to the mounting frame, the is movable in three axial directions; - One on the secondary molding device attached tool for deforming the shaped by the stamp Roughly shaped body in cooperation with the form stamp. A thin sheet metal forming apparatus according to claim 4, in which the tool is formed by two types of tool, namely by a mold for local pressing with a fastener and an elastomer, and a rod-shaped hard tool, the tools removable in a tool holder the secondary Deformation device are used.