EP2277642B1 - Tool and device for manufacturing of moulded parts - Google Patents

Description

The invention relates to a tool for the simultaneous high-pressure forming of at least two metallic workpieces according to the preamble of claim 1. The invention further relates to a device for the production of moldings according to the preamble of patent claim 7.

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 sheet metal, the process of high pressure forming (English hydroforming) has established, which is characterized by great design freedom in the design and allows very high degrees of deformation. 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 transverse to the mold division resulting Forces are absorbed by the hydroforming tool. This stand usually consists of two oppositely arranged, substantially rectangular yokes, which are held together by tie rods. Presses for forming several sheets are in the JP 07116748 A or the US 2003/0177801 A1 described.

JP07116748 discloses a tool according to the preamble of claim 1

A disadvantage of the aforementioned presses that they are formed due to their design and the required dimensions by the forces occurring during the forming process very space intensive. Furthermore, the production throughput of these presses is limited.

The invention aims to remedy this situation. The invention is based on the object to provide a tool and an apparatus for the production of moldings, which allow for a compact design an increased production throughput. According to the invention, this object is achieved by a tool having the features of patent claim 1.

With the invention, a tool for high pressure forming of metallic workpieces is created, which allows for a compact design an increased production throughput. By providing an intermediate tool part which is sandwiched between the upper die part and the lower die part and which has on its side facing the tool upper part a supply line for pressurizing a workpiece with fluid under high pressure and the lower part of the tool facing side is provided with a Umformmatrize, is the simultaneous forming allows several mutually parallel workpieces. It has been shown that the compressive forces applied to the intermediate tool part during the forming process essentially cancel each other out, so that the forces acting on the upper tool part and the lower tool part do not rise proportionally with the forming processes taking place inside the tool, but rather are only insignificantly changed. It follows that the traverses receiving the tool and the tie rods connecting them, despite considerably increased production throughput, do not have to be dimensioned much larger.

According to the invention, the upper tool part and / or the lower tool part has a compensation plate on which the forming die is arranged and which is controlled to be bendable against the process pressure-induced bending direction of the forming die. In this way, a defined bending of the forming die opposite to the process pressure-indicated bend can be achieved, whereby the compensation of the process pressure-induced bending is effected.

In a development of the invention, the supply line of the tool lower part is connected to the supply line of the at least one intermediate tool part. This allows a similar pressurization of the workpieces located in the tool. Such a uniform pressurization causes a uniform pressurization of both sides of the at least one intermediate tool part, whereby the applied compressive forces are canceled against each other.

In a further development of the invention, the compensation plate can be acted upon by a hydraulic plate with fluid pressure such that a bending of the compensation plate can be achieved. As a result, a well controllable bending of the compensation plate is possible.

In an embodiment of the invention, the compensation plate is flat connected to a spacer plate, in which a hydraulic line is introduced, which opens into one of the spacer plate facing recess of the compensation plate. As a result, the formation of a fluid pressure pad is possible, whereby over the surface uniform forming pressure is achieved.

The stated object is further achieved by a device having the features of patent claim 7. 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. Preferably, the trusses have a substantially circular base formed, whereby a uniform introduction of the forming forces is ensured in the tie rods. Preferably, 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.

In an embodiment of the invention, at least one traverse on an annular portion which receives a pressing module, wherein at least two support blocks are arranged, between which at least one passage is formed and over which the distance between the trusses is adjustable to each other. As a result, the distance between the trusses is optimally adjusted to each other depending on the application field.

Preferably, 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 an advantageous embodiment, 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 to 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 performs two functions: firstly, it allows uniform pressurization of the piston carried in the cylinder; 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. On the one hand, these return cylinders serve to displace the piston of the hydraulic cylinder within the cylinder housing, in particular the return cylinders are used to push the piston back into 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.

In an 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 is the possibility the implementation of semi-finished products created from two sides, whereby 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. In development of the invention, both bushings are suitable for clocking through a workpiece to be formed and the tool is designed such that a clocking of at least two superimposed, arranged at right angles to each other workpieces is possible. As a result, the continuous deformation of existing as a coil sheets of mutually offset feeds is possible, whereby an increased production throughput is possible with minimal space requirements.

Figur 1

die schematische, räumliche Darstellung einer Vorrichtung zur Her- stellung von Formteilen;

Figur 2

die Darstellung der Vorrichtung aus Figur 1 im Schnitt (ohne Werk- zeug);

Figur 3

die Darstellung der Vorrichtung gemäß Figur 2 mit zusätzlich ange- ordnetem Kurzhubzylinder;

Figur 4

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

Figur 5

die schematische Darstellung einer Vorrichtung zur Herstellung von Formteilen mit einer Durchführung und mehrteiligen halbkreisförmi- gen Stützblöcken im Schnitt;

Figur 6

die Darstellung der Vorrichtung nach Figur 5 mit zwei Durchführun- gen und mehrteiligen viertelkreisringförmigen Stützblöcken im Schnitt und

Figur 7

die schematische Darstellung einer Vorrichtung nach Figur 6 mit separatem Stützring und mehrteiligem viertelkreisförmigen Stütz- blöcken.

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 a device 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 additional short-stroke cylinder;

FIG. 4

the schematic representation of the hydroform stack tool set of the device FIG. 1 ;

FIG. 5

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

FIG. 6

the representation of the device according to FIG. 5 with two passages and multi-part quarter-circle-shaped supporting blocks in section and

FIG. 7

the schematic representation of a device according to FIG. 6 with separate support ring and multi-part quarter-circle 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 consists essentially of an upper tool part 71 and a lower tool part 72, between which two intermediate tool parts 73 are arranged. The upper tool part 71 includes 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. At its the spacer plate 711 opposite bottom is on the compensation plate a Tool plate 716 is arranged, which has the contour to be formed in the workpiece.

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. The compensation plate 722 has on its side facing the spacer plate 721 in the middle a flat recess 723 which is sealed by a seal 724 against the spacer plate 721 and in which a disposed within the spacer plate 721 hydraulic line 725 opens. In the compensation plate 722, a hydraulic line 726 is arranged, which opens in a on its recess 723 opposite arranged second recess 727 of the compensation plate 722. 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 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.

The tool intermediate part 73 is essentially formed from a tool plate 733 on which a pressure plate 732 is arranged. The tool plate 733 corresponds to the tool plate 716 of the upper tool part 71; the compensation plate 732 substantially corresponds to the pressure plate 722 of the tool lower part 72, but there is no flat depression on the side facing the tool plate 733.

The lines 726, 736 of the compensation and pressure plates 722, 732 are in the exemplary embodiment via - not shown - flexible fluid lines connected to each other. The two intermediate tool parts 73 are mounted vertically displaceably on guide rods 731 in the exemplary embodiment, wherein between the upper tool part 71 and the adjacent intermediate tool part 73, between the lower tool part 72 and the adjacent intermediate tool part 73 and between the intermediate tool parts 73 each compression spring elements 735 are arranged. The compression spring elements 735 ensure a gap between the tool plates 716, 733 and the compensating or pressure plates 722, 732 which are respectively arranged opposite to them for inserting the workpieces to be deformed. Furthermore, they are slidably connected to the tool upper part 71 for guiding the tool intermediate parts 73 via laterally arranged drivers 730.

During the forming of between the upper tool half 71 and the intermediate tool part 73, between the two intermediate tool parts 73 and the intermediate tool part 73 and the lower tool half 72 incorporated workpieces are the workpieces via the lines 726, 736 acted upon under high pressure with fluid and to the contour of the Tool plates 716, 733 pressed. In this case, the compensation and pressure plates 722, 732 are sealed off from the respective workpiece via the seals 728, 738. 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 compensation plate 722 of the lower tool part 72, a compensating counterbending is likewise effected via the flat depression 723.

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 passage of workpieces to be formed is formed (see Fig. 8). This passage 30 is suitable in the embodiment for clocking through slit strip. Through the use of 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. 5 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. 5 to 7 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. 6 and 7 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 of workpieces through and a narrow passage, the two opposite openings of the additional processing, for example by means of laser can be used, are formed.

Claims (14)

1. Tool for the simultaneous high-pressure moulding of two or more metal workpieces, comprising a tool upper member with a forming die and a tool lower member with a feed line to apply fluid under high pressure to a workpiece, where between the tool upper member (71) and the tool lower member (72) one or more tool intermediate members (73) is or are arranged sandwich-fashion, the side of which tool intermediate member or members (73) towards the tool upper member (71) incorporates a feed line (736) to apply fluid under high pressure to a workpiece and the side of which towards the tool lower member (72) is provided with a forming die, the tool upper member (71) and/or the tool lower member (72) incorporates a compensation plate (712, 722) on which the forming die is disposed and which can be controlledly bent against the bending direction of the forming die.
2. Tool in accordance with claim 1, characterised in that the feed line (725) of the tool lower member is connected to the feed line (736) of the one or more tool intermediate members (73).
3. Tool in accordance with claim 1 or 2, characterised in that the one or more tool intermediate members (73) is or are displaceably mounted so as to be guided vertically between the tool upper member (71) and the tool lower member (72).
4. Tool in accordance with claim 3, characterised in that disposed between the tool upper member (71) and tool lower member (72) are one or more guide rails (731) by means of which the one or more tool intermediate members (73) is or are guided vertically, where spring elements (733) are disposed to space the one or more tool intermediate members (73) apart from vertically adjacent tool members (71, 72, 73) in an unloaded condition.
5. Tool in accordance with any one of the aforementioned claims, characterised in that fluid pressure can be applied to the compensation plate (712, 722) via an hydraulic line (715, 725) so that the compensation plate (712, 722) can be bent.
6. Device for manufacturing moulded parts, comprising two cross members which are connected together via tie rods, characterised in that disposed between the cross members (11, 12) is a pressure module to receive a multi-stage tool (7) in accordance with claims 1 to 6.
7. Device in accordance with claim 6, characterised in that one or more cross members (11, 12) incorporates or incorporate an annular portion to receive a pressure module, where two or more support blocks (3) are disposed between which one or more ducts (30) is or are formed and by means of which the distance between the cross members (11, 12) can be adjusted.
8. Device in accordance with claim 6 or 7, characterised in that one or more annular portions of a cross member (11, 12) is or are constructed as a separate support ring (2) which is positively connected to the cross member (11, 12).
9. Device in accordance with claims 6 to 8, characterised in that the pressure module incorporates one or more hydraulic cylinders.
10. Device in accordance with claim 9, characterised in that the hydraulic cylinder is formed by an annular portion in which a piston (4, 5) is guided.
11. Device in accordance with any one of claims 6 to 10, characterised in that two support blocks (3) constructed essentially semi-circular are disposed between which is formed a duct (30) suitable for passing stepwise through it a workpiece to be moulded.
12. Device in accordance with any one of claims 6 to 10, characterised in that four support blocks (3) constructed essentially quadrant-shaped are disposed between which are formed two ducts (3) of which one or more ducts (30) is suited for passing stepwise through it a workpiece to be moulded.
13. Device in accordance with any one of claims 7 to 12, characterised in that the support blocks (3) are formed from a number of subsegments (31) placed on top of one another.
14. Device in accordance with claim 12 or 13, characterised in that both ducts are suitable for passing stepwise through them a workpiece to be moulded and that the workpiece is constructed so that one or more workpieces fed in one on top of the other and disposed at right angles to one another can be passed stepwise through them.

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