EP1268099B1 - Method for producing components using a flowable active medium and a forming tool - Google Patents

Abstract

The invention is for a method to produce components from a blank made of deep-drawable material using a free-flowing action medium. The method consists in clamping the blank in a forming device in which the action medium applies a pressure to the blank, preforming the blank be elevating the pressure exercised by the action medium in restricted areas of the blank and finish forming the preformed blank with a forming tool.

Description

The invention relates to a method for producing Components of one of a thermoformable material, especially steel, using existing board a flowable active medium (see, e.g., U.S. Patent No. 5,632,172).

For the production of complex components with improved component properties taking advantage of Properties of the board material used in each case On the one hand, reshaping of individual boards is suitable with the help of liquid active media and on the other hand the Hydroforming of welded blanks or similar hollow body. When forming from simple Boards using Wirkmedien be the Boards usually by means of a punch or a comparable mold to its final form, wherein the respectively used molding tool (stamp or Die) against one of a fluid cushion applied Support pressure works. When hydroforming is against a between the boards or in the hollow body existing cavity filled with hydraulic fluid and with high pressure applied. By the thus produced Internal pressure is the respective workpiece in by a the workpiece surrounding die pressed predetermined shape.

In the production of deep-drawn or hydroformed parts with complicated Geometry is in many cases the manufacture of Intermediate forms required because the final contour is not in a forming step can be generated. The intermediate form is usually generated in tools that regardless of how to make the final shape used tool work. This division of Tools and work steps increases the required Investment costs significantly and consequently increases an increase in the production of components of the costs involved.

In addition to the above-explained method for Production of intermediate forms with additional Tools become such intermediate forms in practice also produced by hydromechanical forming. at In this method, the board to be reshaped before Main transformation by means of the active medium in the actual Forming tool preformed. Only after the pre-deformation is completed, finds the actual preforming instead of reaching the Enform of the workpiece only becomes. To achieve this corresponds to the Preform geometry usually at least the outline of shaping tool element. This procedure with The pre-deformation proves in many cases as unfavorable with regard to the subsequent Main forming. However, this disadvantage has the advantage opposite, that in the middle of the component higher changes in shape can be achieved, so that targeted solidifications produced and better exploited the material properties can be.

The object of the invention is a method specify with which complex shaped components under optimized use of the properties of the can be produced.

• Spannen der Platine in einer Umformeinrichtung, in welcher die Platine mindestens auf einer Seite mit dem Wirkmedium beaufschlagt wird;
• Vorformen der Platine durch Erhöhen des von dem Wirkmedium ausgeübten Drucks in einem Bereich der Platine, welcher auf einen Teilabschnitt der Platinenfläche beschränkt ist und den Flächenabschnitt der Platine, aus dem die Endform des Bauteils erzeugt wird, teilweise überdeckt, sowie
• Fertigformen der vorgeformten Platine mittels eines Formwerkzeugs.

This object is achieved by a method of the type specified, in which the following steps are performed:

• Clamping the board in a forming device, in which the board is acted upon at least on one side with the active medium;
• Preforming the board by increasing the pressure exerted by the active medium pressure in a region of the board, which is limited to a portion of the board surface and partially covers the surface portion of the board from which the final shape of the component is produced, and
• Finishing the preformed board by means of a molding tool.

According to the invention are from the board in one first step partially preformed semi-finished products using flowable active media in one produced suitable forming device. For this preformed semifinished product is then the final form of the Molded component.

The preforming takes place only in one limited area of the board. Preforming thus serves unlike, for example, a multi-level Deep drawing of components not intended for training Form elements, which in a further working stroke for It will be shaped as a preform produced in terms of material deformation and distribution and use of the Material properties optimal for the required Properties of the finally produced component is prepared. Thus, the preform according to the invention only generated in the areas where these are in terms of the geometric (settlement) and / or component-specific properties (strength) required are.

Depending on the end product Requirements may be the pre-deformation of the board without or with the help of a counterform. The Preform without counterform has the advantage that the Material of the board during pre-deformation unhindered can flow, so that, for example, an optimized Strength of the preform is achieved. The use of a Counterform has the advantage that the preform also optimal in terms of their spatial design can be prepared for the final shape to be generated. This can be a compromise between the free and the complete reshaping in a counterform thereby be found that the preformed portion of the board at the end of the pre-deformation only in a partial area at the Gegenform rests while in the other subarea a free deformation takes place.

The transformation of the preformed board to the final shape of the Component preferably takes place against one of a Working medium applied support pressure. That way a carefully shaped, exactly shaped, produce high quality component, which due to the gentle processing optimized mechanical Properties and a good visual appearance having.

The preformed blanks according to the invention can be connected to each other before the final deformation of the component, so that particularly large-area components or components can be manufactured in which the material distribution or the strength of the material present in the areas of the various boards targeted at the practical Use locally each occurring loads of the component are adapted.
The boards can be material, force and / or positively connected with each other. Alternatively, loosely superimposed boards can be brought together in the final shape after preforming.

Hollow molds can be with the invention Then make training especially easy if between the superimposed and possibly with each other connected, preformed boards already have a cavity is available. The forms thus formed are in particular suitable, by a hydroforming in the final shape the component to be molded, wherein the cavity during the final deformation of the boards to the final shape with high pressure is applied.

Fig. 1

eine aus Feinblech bestehende Platine in perspektivischer Ansicht;

Fig. 2

ein aus der Platine geformtes Bauteil in einem Querschnitt;

Fig. 3

die im Zuge des in Fig. 2 gezeigten Bauteils vorgeformte Platine im Querschnitt;

Fig. 4

eine andere aus Feinblech bestehende Platine in perspektivischer Ansicht;

Fig. 5

eine durch zwei vorgeformte Platinen der in Fig. 4 gezeigten Art gebildete Hohlform im Querschnitt;

Fig. 6

eine andere durch zwei vorgeformte Platinen der in Fig. 4 gezeigten Art gebildete Hohlform im Querschnitt;

Fig. 7

eine erste Einrichtung zum Vorformen von Platinen der in Fig. 1 oder 4 gezeigten Art im Querschnitt;

Fig. 8

eine zweite Einrichtung zum Vorformen von Platinen der in Fig. 1 oder 4 gezeigten Art im Querschnitt;

Fig. 9

eine erste Einrichtung zum Fertigformen von in Vorrichtungen der in Fig. 7 oder 8 dargestellten Art vorgeformten Platinen im Querschnitt;

Fig. 10

eine zweite Einrichtung zum Fertigformen von in Vorrichtungen der in Fig. 7 oder 8 dargestellten Art vorgeformten Platinen im Querschnitt.

The invention will be explained with reference to embodiments showing drawings. They show schematically:

Fig. 1

a sheet made of sheet metal in perspective view;

Fig. 2

a formed from the board component in a cross section;

Fig. 3

the in the course of the component shown in Figure 2 preformed board in cross section;

Fig. 4

another sheet made of thin sheet in perspective view;

Fig. 5

a formed by two preformed boards of the type shown in Figure 4, the hollow shape in cross section;

Fig. 6

another in cross section formed by two preformed blanks of the type shown in Figure 4;

Fig. 7

a first device for preforming boards of the type shown in Figure 1 or 4 in cross section.

Fig. 8

a second means for preforming boards of the type shown in Figure 1 or 4 in cross section;

Fig. 9

a first device for the finish molding of blanks preformed in devices of the type illustrated in Fig. 7 or 8 in cross-section;

Fig. 10

a second device for the finishing of preformed in devices of the type shown in Fig. 7 or 8 illustrated blanks in cross section.

In the course of the preparation of the shown in Fig. 1 and 4 Boards P1, P2 will be the respective board P1, P2 in individual areas B1, V1 and B2, V2 divided. It will distinguished between the area B1 and B2, from the each of the finished deformed component is generated, and the Range V1, V2, in which the pre-deformation of the respective Board P1, P2 is made.

The position of the pre-deformation intended areas V1 or V2 of the boards P1 and P2 is dependent on the zu generating geometry of the finished component. For the Interpretation of this area V1, V2 therefore plays the in Fig. 2 exemplified settlement ratio over the cross section of the finished component a crucial Role. The geometry of the in Figures 3 and 5 and 6 exemplified partially preformed boards P1, P2 and P3 should be interpreted as preforming subsequent final molding, no failure by Material overload or impermissible wrinkling occurs.

The intended for the pre-deformation range V1 and V2 if necessary within the outline of the Area B1 lie (Fig. 3), from which the to be generated Component is finished molded. Its contour is in Fig. 3 indicated by dashed lines and corresponds to the shown in Fig. 2.

For a different kind of geometry or another Requirements for the properties of the finished component however, preforming may also be required the board P2 in a range V2, the in Teilbabschnitten the respective area B2, from which the Component is finished, goes out (Fig. 4). A complete coverage of area B2 by the for However, the preforming area V2 is also in not provided in this case. Instead, the finds Pre-deformation only takes place where one appropriate preparation of the board P1 or P2 for the subsequent finished shapes appropriate and necessary is. Of course, the number of for the Preforms do not include one limited, but it may, if necessary, several determined such preform areas on a board become.

For pre-forming the board P1 or a corresponding the board P2 in a vorzuverformenden area and an area from which the final shape of the produced Component is generated, subdivided board P4 Forming U1, U2 used. These wise one each with a liquid active medium, For example, water, filled container 1 on. In addition, the forming devices U1, U2 are each with a holding device 2, which each preformed board P1, P4 in their edge regions hold the edge surrounding an opening of the container 1. In this way, the board P1 or P4 is above the Opening tensioned, so that their the container interior assigned side are acted upon with the active medium can. The course of the edge of the opening of the container. 1 corresponds in each case to the course of the edge of the the preforming provided area V1 and V2 of each processed board P1, P4.

In contrast to the forming device U1, in the how shown in Fig. 7 using the example of the board P1, the Preforming the board P1 is done without counterform, is the Forming device U2 equipped with a counter-mold 3, the distance from the opening in this example the container 1 tensioned board P4 is arranged.

By increasing the pressure exerted by the active medium pressure P is the respective board P1 or P4 in the range of Container opening in an outward movement bulged. In this case, in the forming device U1 to a completely free flow at the end of the pre-deformation of the steel material of the board P1.

In contrast, sets in the forming device U2 of Pre-formed area V2 of the board P4 after a certain time of free deformation of the counter-mold 3 on, so that a portion of the pre-deformed area V2 the shape of the counter-mold 3 is impressed. The Geometry and the dimensions of the freely deformed Section V2a of the board P4 are dependent on the Position of the counterform 3 with respect to the opening of the Container 1.

After the pre-deformation in the forming U1 or U2 can the boards P1 - P4 individually to the respective component are formed (Fig. 2). To may in a conventional manner with a stamp 10th and a die 11 equipped device F1 can be used, as exemplified in Fig. 9 is shown.

Alternatively, the preforming of the boards P1 - P4 also be performed in a device F2, which a container 20 for an active medium 21, in particular Water, and a holding device 22 has. By the Holding device 22 is for example the preformed Board P1 held in the opening of the container 20.

The finished molding of the board P1 is then done by means a punch 23, which in the opening of the container 20th is insertable and in the end face the shape of the forming component is formed. At a work stroke of the punch 23 is the preformed board P1 in the Container 20 pulled. In doing so, this exercises in the container 20 contained active medium one of the force of the punch 23rd opposing support pressure S, so that the preformed board P1 with increasing stroke of the Stamp 23 puts on these and so on by the stamp 23 given form.

It is also possible, for example, in the two Device V1 preformed boards P2, P3 superimposed so that they hollow body H1 (Fig. 5) or H2 (Fig. 6), which respectively at its upper and Bottom have a preformed area V2, V3. In this case, the respective hollow body H1, H2 forming boards P2, P3 are welded together, so that they form a structural unit. The shape of the thus formed hollow bodies H1, H2 finished molded Components is shown in dashed lines in FIGS. 5 and 6 Lines indicated.

The pre-formed hollow bodies H1, H2 can be particularly well finished by applying pressure to hydroforming. For this purpose, the hollow body H1, H2 in a die a suitable device, not shown here positioned and with a flowable active medium, for example, water, filled. Subsequently, the Impact medium pressurized, so that the Sheet material of the respective hollow body H1, H2 expands, until it is completely against the walls of the die.

REFERENCE NUMBERS

1

Container,

2

Holding device,

3

Counter-mold,

10

Stamp,

11

Die,

20

Container,

21

Active medium,

22

Holder,

23

Stamp,

F1, F2

Device for finishing,

B1, B2

Area from which each of the finished deformed Component is generated,

H1, H2

Hollow body

P

Print,

P1, P2, P3, P4

boards,

S

Support pressure,

U1, U2

forming equipment,

V1, V2, V3

Area in which each of the pre-deformation of the Boards P1, P2 is made,

v2a

free deformed section of the board P4,

Claims (11)

1. A method for producing components from a blank (P1 - P4) made of a deep-drawable material, particularly steel, using a free-flowing action medium, in which the following steps are performed:

   clamping the blank (P1 - P4) in a forming device (U1, U2), in which the blank (P1 - P4) has the action medium applied to it;

   characterized by:

   preforming the blank (P1 - P4) by elevating the pressure (P) exercised by the action medium in a region of the blank (P1 - P4) which is restricted to a section (V1, V2) of the blank surface and which partially covers the surface section (B1, B2) of the blank (P1 - P4) from which the final form of the component is generated, and

   finish forming of the preformed blank (P1 - P4)using a forming tool (F1, F2).
2. The method according to Claim 1,
   characterized in that the blank (P1 - P4) is preformed without a counter mold.
3. The method according to Claim 1,
   characterized in that the blank (P1 - P4) is preformed with a counter mold (3).
4. The method according to Claim 3,
   characterized in that the preformed region (V1, V2) of the blank (P1 - P4) partially presses against the counter mold (3) at the end of the preforming.
5. The method according to Claim 3,
   characterized in that the preformed region of the blank (P1 - P4) presses completely against the counter mold (3) at the end of the preforming.
6. The method according to one of the preceding claims,
   characterized in that the forming of the preformed blank (P1 - P4) into the final form of the component is performed against a supporting pressure (S) exercised by an action medium.
7. The method according to one of the preceding claims,
   characterized in that after the preforming at least two blanks (P1 - P4) are connected to one another and the blanks (P1 - P4) are finish formed jointly into a final form.
8. The method according to Claim 7,
   characterized in that the preforms are connected to one another by material bonding, friction, and/or form fit. ,
9. The method according to one of Claims 1 to 6, characterized in that after the preforming at least two blanks (P1 - P4) are laid loosely on one another and the blanks (P1 - P4) are finish formed jointly into a final form.
10. The method according to one of Claims 7 to 9,
    characterized in that a cavity is present between the blanks (P1 - P4).
11. The method according to Claim 10,
    characterized in that the cavity has a high pressure applied to it during the finish forming of the blanks (P1 - P4) into the final form.

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