EP2221126B1 - Device for forming workpieces - Google Patents

Abstract

The device has two cross beams (11, 12) interconnected by a cylinder-shaped tie rod (13), where one of the cross beams includes an annular section accommodating a pressing module. A passage is formed between two supporting blocks (3) that allow the distance between the cross beams to be adjusted. The cross beams include a circular shaped footprint. An end of the tie rod is provided with a clamping device. A retaining ring (2) is interlockly connected with the cross beams. The pressing module includes a hydraulic cylinder.

Description

The invention relates to a device for producing molded parts, comprising two cross members, which are connected to each other via tie rods (see, for example EP-A-1 1 075 882 ).

For the production of workpieces by a chipless forming process usually presses are used in which forming tools are used to receive a workpiece blank and then bring this by appropriate force into the desired shape. In particular, in the field of forming plate-shaped semi-finished products, such as sheets, but also for forming other semi-finished products, such as pipes, the process of high pressure forming (English: Hydroforming) has established itself, which is characterized by great design freedom in the design and very high degrees of deformation allows. The semi-finished product is pressed with very high pressure against a mold, whereby the deformation is achieved. This creates large, acting in opposite directions forces that must be absorbed by a stand. The forces arising transversely to the mold division are absorbed by the hydroforming tool. This stand consists in The rule of two oppositely arranged, substantially rectangular yokes, which are held together by tie rods.

A disadvantage of the aforementioned presses that they are formed very space intensive due to their design and the required dimensions by the forces occurring during the forming process. Furthermore, the prior art presses are inflexible in terms of the use of different tools with different Einformtiefen.

The invention aims to remedy this situation. The present invention has for its object to provide a device for the production of moldings, which is compact and allows variable use with little Umrüstaufwand. According to the invention, this object is solved by the features of claim 1.

With the invention, an apparatus for the production of moldings is created, which is compact and allows variable use with little conversion effort. By providing the at least two support blocks, the distance between the two trusses is adjustable to each other, whereby a variable adaptation of the press to different tools with different Einformtiefen is possible. In addition, between the two support blocks, a passage is formed, which allows a passage of the semi-finished products to be deformed, that is, the workpiece to be deformed can be introduced on one side of the implementation in the device, which after deformation on the other side of the implementation leaves again. By providing such an implementation, the transformation of sheets in a through-stroke method is made possible.

The term "pressing module" is understood below to mean any device which is suitable for exerting a compressive force in the direction of the oppositely arranged traverse. The device according to the invention is in use Forming tools suitable for the process of hydroforming, but it is not limited to this method.

In development of the invention, the trusses have a substantially circular base formed. This ensures a uniform introduction of the forming forces in the tie rods.

In an embodiment of the invention, the tie rods are cylindrical and provided at least one end with a clamping device. As a result, a simple conversion of the device is possible. The upper traverse can be easily removed from the tie rods or attached to this, after which the tie rods are fixed to the tensioner on the crossbar. The tensioning device may be formed, for example, by a threaded portion of the tie rods, on which the tension is made possible by a nut. Any suitable device for releasably tensioning and fixing a tie rod is suitable. This also includes the generation of the bias voltage via the machine's own cylinder (s) with mechanical blocking of the resulting clamping distance.

In a further embodiment of the invention, at least one annular portion of a traverse is formed as a separate support ring, which is positively connected to the traverse. By providing a separate support ring notch effects are avoided, as they occur when providing a cylindrical recess between the bottom and side walls of such a recess. Upon the occurrence of horizontally acting forces, the support ring can expand outwards, without causing damage to the cross-member positively connected to this support ring.

In a further development of the invention, the pressing module comprises at least one hydraulic cylinder. As a result, a position of the molded part is made possible to the tool. In addition, a short-stroke cylinder can be mounted on the cylinder piston. Such cylinders allow a defined employment of the molding the tool and ensure that the tool is optimally closed during the forming process.

In an embodiment of the invention, the hydraulic cylinder is formed by an annular portion in which a piston is guided. This allows a compact design while minimizing components. The Traverse provided with an annular section also assumes the function of a cylinder housing.

Preferably, the traverse is provided with at least one cylinder bore for fluid supply of the hydraulic cylinder. The fluid fulfills two tasks: first, it allows a uniform pressurization of the guided in the cylinder piston; On the other hand, it forms a pressure pad between the cylinder / traverse and the piston and thus serves to decouple the traverse and the piston, which counteracts a deflection of the piston.

Advantageously, at least two return cylinders for guiding the piston of the hydraulic cylinder are arranged. These return cylinders are used for a displacement of the piston of the hydraulic cylinder within the cylinder housing, in particular the return cylinders are used to push the piston back to the starting position. On the other hand, the return cylinder serve the leadership of the piston of the hydraulic cylinder and thus prevent tilting and twisting of the piston. Alternatively or additionally, other guide systems can also be used.

In an embodiment of the invention, the pressing module has a receptacle for a hydroforming tool. As a result, the device according to the invention for the high-pressure forming process can be used.

In a further embodiment of the invention, two substantially semicircular support blocks are arranged between which a passage is formed suitable for clocking through a sheet to be formed. As a result, the continuous deformation of existing as a coil sheets is possible.

In an alternative embodiment of the invention, four substantially quarter-circular ring-shaped support blocks are arranged, between which two passages are formed, of which at least one passage is suitable for clocking through a sheet to be formed. By the second implementation, a post-processing of a molded part, for example by means of laser allows. With sufficient width of the second implementation even the possibility of carrying out semi-finished products from two sides is created. As a result, the flexibility of the device is further increased.

In a further embodiment of the invention, the support blocks are formed from a plurality of stacked, preferably plate-like sub-segments. As a result, a stepwise change in the height of the support blocks by adding or removing individual sub-segments is possible. Alternatively, the support blocks can also be segmented vertically.

Figur 1

die schematische, räumliche Darstellung einer Vorrichtung zur Herstellung von Formteilen;

Figur 2

die Darstellung der Vorrichtung aus Figur 1 im Schnitt (ohne Werkzeug);

Figur 3

die Darstellung der Vorrichtung gemäß Figur 2 mit zusätzlich angeordnetem Kurzhubzylinder;

Figur 4

die schematische Darstellung des Hydroform-Werkzeugs der Vorrichtung aus Figur 1;

Figur 5

die schematische Darstellung eines Hydroform-Werkzeugs in einer weiteren Ausführungsform;

Figur 6

die schematische Darstellung eines Hydroform-Werkzeugs in einer dritten Ausführungsform;

Figur 7

die dreidimensionale Schnittdarstellung des Werkzeugs aus Figur 5 mit umgeformten Blech;

Figur 8

die schematische Darstellung einer Vorrichtung zur Herstel- lung von Formteilen mit einer Durchführung und mehrteiligen halbkreisringförmigen Stützblöcken Schnitt;

Figur 9

die Darstellung der Vorrichtung nach Figur 8 mit zwei Durchführungen und mehrteiligen viertelkreisringförmigen Stützblöcken im Schnitt und

Figur 10

die schematische Darstellung einer Vorrichtung nach Figur 9 mit separatem Stützring und mehrteiligen viertelkreisringförmi- gen Stützblöcken.

Other developments and refinements of the invention are specified in the remaining subclaims. An embodiment of the invention is illustrated in the drawings and will be described in detail below. Show it:

FIG. 1

the schematic, spatial representation of an apparatus for the production of moldings;

FIG. 2

the representation of the device FIG. 1 on average (without tools);

FIG. 3

the representation of the device according to FIG. 2 with additionally arranged short-stroke cylinder;

FIG. 4

the schematic representation of the hydroforming tool of the device FIG. 1 ;

FIG. 5

the schematic representation of a hydroforming tool in another embodiment;

FIG. 6

the schematic representation of a hydroforming tool in a third embodiment;

FIG. 7

the three-dimensional sectional view of the tool FIG. 5 with formed sheet metal;

FIG. 8

the schematic representation of an apparatus for the production of moldings with a passage and multi-part semicircular support blocks section;

FIG. 9

the representation of the device according to FIG. 8 with two bushings and multi-part quarter-circle-shaped supporting blocks in section and

FIG. 10

the schematic representation of a device according to FIG. 9 with separate support ring and multi-part quarter circle ring-shaped support blocks.

The chosen as an exemplary embodiment apparatus for the production of molded parts is designed for the process of hydroforming and comprises a housing 1, which is formed by two cylinder-like, oppositely arranged trusses 11, 12, which are circumferentially connected together by tie rods 13. The tie rods 13 are formed as cylindrical rods, which have at both ends - not shown - external thread which receive nuts 131 for clamping the tie rods 13. The tie rods may alternatively have an oval or polygonal cross-section.

The trusses 11, 12 have centrally a circular shoulder 111, 121 for the positive reception of a circumferential support ring 2. The support rings 2 have an outer diameter identical to the crossbars 11, 12 and an inner diameter corresponding to the outer diameter of the shoulders 111, 121.

Within the support rings 2, a piston 4, 5 is arranged in each case, such that in cooperation with in each case one cross member 11, 12 with a arranged support ring 2, a hydraulic cylinder is formed. Traverse 11, 12 and support ring 2 thereby form the cylinder housing in which the piston 4, 5 is slidably guided. In the trusses 11, 12, a cylinder bore 112, 122 is respectively centrally inserted, which serves to supply the hydraulic cylinder thus formed with hydraulic fluid. For this purpose, the cylinder bores 112, 122 are each connected to a - not shown - hydraulic line.

In an alternative embodiment, only the lower provided with a cylinder bore 121 cross member 12 may be formed with the arranged on this support ring 2 in interaction with the piston 5 as a hydraulic cylinder and the upper cross member, which must have no cylinder bore 112, takes within the support ring 2 a Pressure pad, for example, a rubber pad on which the upper piston 4 is applied. Here, the rubber cushion is the deflection compensation; a pressurization of the upper piston 4 in the direction of the opposite lower piston 5 is not carried out.

Between the pistons 4, 5, four back pressure cylinders 9 are arranged in the embodiment. The return cylinders 9 are used in the direction of the trusses 11, 12 directed return movement of the pistons 4, 5 within the support rings 2. In addition, over the back pressure cylinder 9 a Verkannten the piston 4, 5 can be prevented within the support rings 2.

To the pistons 4, 5, a spacer plate 711, 721 of a hydroforming tool 7 is attached in each case. To optimize the employment of a workpiece to be reshaped, an additional short-stroke cylinder 6 can be arranged on the lower piston 5 (cf. Fig. 3 ), on which in turn the lower spacer plate 721 is mounted. Of course, an arrangement of an additional Kurzhubzylinders on upper piston 4 is possible.

The hydroforming tool 7 essentially consists of an upper tool part 71 and a lower tool part 72. The upper tool part 71 comprises an upper spacer plate 711 to which a compensation plate 712 for deflection compensation is attached. The compensation plate 712 has on its side facing the spacer plate 711 centered on a surface recess 713 which is sealed by a seal 714 against the spacer plate 711 and in which a disposed within the spacer plate hydraulic line 715 opens. On its underside facing away from the spacer plate 711 a tool plate 716 is arranged on the compensation plate, which has the einzuformende in the workpiece 8 contour.

The lower tool part 72 includes a lower spacer plate 721 to which a compensation plate 722 for deflection compensation is attached. In the embodiment according to FIG. 4 is the lower spacer plate 721 identical to the upper spacer plate 711 formed. On its side facing the spacer plate 721, the compensation plate 722 has a center depression 723 in the middle, which is sealed off from the spacer plate 721 by a seal 724 and in which a hydraulic line 725 arranged within the spacer plate opens. In the middle of the recess 723, a vertically formed hydraulic line 726 is arranged in the compensation plate 722, which opens into a second recess 727 of the compensation plate 722 arranged opposite the recess 723 thereof. The second, the upper mold half 71 facing recess 727 is sealed by a seal 728 during the forming process relative to the overlying workpiece 8 to be machined. The seal can also be purely metallic, that is without seal 728 done.

The depressions 713, 723, 727 are formed only very flat and serve the areal distribution of the fluid supplied via the hydraulic lines 715, 725, 726, whereby a pressure pad is formed. During the forming of a workpiece 8 introduced between the upper tool half 71 and the lower tool half 72, the workpiece 8 is subjected to fluid under high pressure via the lines 723, 727 and to the contour of the tool plate 716 In this case, the compensation plate 722 is sealed off from the workpiece 8 via the seal 728. Possible deflections of the tool plate 716 caused by the applied forming pressure can be compensated by applying a fluid to the compensation plate 712 under pressure via the line 715, thereby causing a deflection in or against the pressure-indicated direction (defined adjustability of the pressure deflection of the tool plate 716). , On the lower compensation plate 722 a compensating counterbending is also effected via the flat depression 723.

In the embodiment according to FIG. 6 the hydraulic supply line 725 is also located within the compensation plate. In the lower spacer plate 721 no hydraulic line is required here.

In the embodiment according to FIG. 5 the conduit 726 is formed within the compensation plate such that it is separated from the hydraulic conduit 725 disposed within the spacer plate 721 and can be fed via a separate fluid supply. As a result, regardless of the pressure applied to the forming within the line 726, the compensation plate 722 can be pressurized via the line 725 by means of a fluid, thus achieving a defined deflection in the direction of the upper tool half 71 for compensation.

Between the support rings 2 are in the embodiment according to FIG. 1 arranged two substantially semi-annular support blocks 3, which limit the distance between the two support rings 2 to each other by their height. Through the two semi-annular support blocks 3, a passage 30 for the implementation of reshaped workpieces 8 is formed (see. Fig. 8 ). This passage 30 is suitable in the embodiment for clocking through slit strip. By using different support blocks 3, the distance between the support rings 2 can be varied, whereby the effective processing height between the pistons 4, 5 is adjustable.

In the embodiment according to FIG. 8 the support rings 2 are integrally formed on the trusses 11, 12. However, this embodiment involves the disadvantage of the notch effect, whereby the trusses 11, 12 are weakened inside in the transition to the support rings 2.

In the embodiment according to FIGS. 8 to 10 the support blocks 3 are formed by stacked, plate-like sub-segments 31. By adding or removing individual sub-segments 31, an optimum adjustment of the working height between the pistons 4, 5 is adjustable.

In the embodiment according to FIGS. 9 and 10 four quarter circular annular support blocks 3 are arranged, which in turn are formed of a plurality of stacked sub-segments 31. The arrangement of four quarter-ring-like support blocks two orthogonal to each other through holes 30 are formed, whereby a clocking from two sides is possible. The support blocks may alternatively also be designed such that a wide passage for the passage through of workpieces 8 and a narrow passage, the two opposite openings of the additional processing, for example by means of a laser, are formed.

The subject matter of the present invention is not limited to the high-pressure forming process, but rather different forming devices can be used between the traverses 11, 12. For example, it is also possible to effect the required forming pressure by the two opposite hydraulic cylinders formed by the cross members 11, 12 with support rings 2 and in these guided pistons 4, 5, wherein the respective tool dies are arranged on the pistons 4, 5.

Claims (21)

1. Device for forming workpieces consisting of two tie-bars which are connected to one another by tension rods, characterised in that at least one of the tie-bars (11, 12) has a ring-shaped section to receive a press module and where at least two support blocks (3) are arranged, between which at least one leadthrough (30) is formed, and by means of which the distance between the tie-bars (11, 12) can be adjusted with reference to one another.
2. Device in accordance with claim 1, characterised in that the tie-bars (11, 12) have a base surface which is substantially circular in shape.
3. Device in accordance with claim 1 or claim 2, characterised in that the tension rods (13) are cylindrical in shape and are fitted with a clamping device at at least one end.
4. Device in accordance with one of the above claims, characterised in that at least one circular section of a tie-bar (11, 12) is formed as a separate support ring (2) which is connected positively to the tie-bar (11, 12).
5. Device in accordance with one of the above claims, characterised in that the press module comprises at least one hydraulic cylinder.
6. Device in accordance with claim 5, characterised in that the hydraulic cylinder is formed by a ring-shaped section in which a piston (4, 5) is guided.
7. Device in accordance with claim 5 or claim 6, characterised in that at least two return cylinders (9) are arranged to guide the piston (4, 5) of the hydraulic cylinder.
8. Device in accordance with one of the above claims, characterised in that the press module has a seat for receiving a fluid-forming tool (7).
9. Device in accordance with one of the above claims, characterised in that at least one of the tie-bars (11, 12) has at least one cylinder bore (112, 122) to supply a hydraulic cylinder with fluid.
10. Device in accordance with one of the above claims, characterised in that two substantially semi-circular support blocks (3) are arranged, between which a leadthrough (30) is formed, suitable for the through-transport in cycles of a workpiece (8) for forming.
11. Device in accordance with one of the claims 1 to 9, characterised in that four substantially quarter-circular support blocks (3) are arranged between which two leadthroughs (30) are formed, of which at least one leadthrough (30) is suitable for the through-transport in cycles of a workpiece (8) for forming.
12. Device in accordance with one of the above claims, characterised in that the support blocks (3) are formed by several part segments (31) stacked on top of one another.
13. Device in accordance with one of the above claims, characterised in that a hydroforming tool (7) is arranged which has a means of compensating the sagging of a tool plate (716) caused by the pressure of the process.
14. Device in accordance with claim 13, characterised in that the means of compensating comprise a compensation plate (712) which can be bent by hydraulic pressure in or against the direction of bending of the tool plate (716) induced by the pressure of the process.
15. Device in accordance with claim 14, characterised in that the compensation plate (712) has a recess (713) for generating a hydraulic pressure pad.
16. Device in accordance with claim 15, characterised in that the surface of the compensation plate (712) is connected to a spacer plate (711) which contains at least one hydraulic duct (715) which opens into the recess (713) in the compensation plate (712).
17. Device in accordance with one of the claims 14 to 16, characterised in that a second compensation plate (722) is arranged to compensate the bending of the workpiece (8) induced by the process, and which is attached to a second spacer plate (721) arranged opposite the spacer plate (711) and serves to support the workpiece (8).
18. Device in accordance with claim 17, characterised in that the second compensation plate (722) has a recess (727) on the side facing away from the spacer plate (721), into which at least one hydraulic duct (726) running within the compensation plate (722) opens.
19. Device in accordance with claim 17 or claim 18, characterised in that the second compensation plate (722) has a recess (723) on the side facing towards the spacer plate (721), into which at least one hydraulic duct (726) running within the spacer plate (721) opens.
20. Device in accordance with claim 18, characterised in that the second compensation plate (722) has a recess (723) on the side facing towards the spacer plate (721), into which a hydraulic duct (726) running within the compensation plate (722) opens.
21. Device in accordance with one of the claims 13 to 20, characterised in that the spacer plates (712, 722) of the hydroforming tool (7) arranged opposite are identical in shape.

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