EP0940199A2 - Device for the hydraulic forming of hollow metallic bodies - Google Patents

Abstract

The device consists of a press frame (2) with a forming tool (7). The tool has a lower part (8), which moves vertically between an open and a closed position, and a moveably supported upper part (9). The lower part is locked in closed position by a pivoted locking body (16), and the upper part is pressed against it by hydraulic force. An upper part is supported in the press frame via a hydraulic pad (13), which has at least one piston-cylinder unit (14,15).

Description

The invention relates to a device for hydraulic Forming of metallic hollow bodies with one in one Press frame arranged mold.

For the hydraulic forming of hollow metal bodies, in particular tubular components, by means of high pressure it is known to initially open the hollow body two-part mold consisting of upper part and lower part to place, then close the mold and then at least at one end of the hollow body Fix sealing mandrel, via which a hydraulic internal high pressure is applied in the hollow body to this according to the given contours in the mold deform.

Hydraulic locking presses predominantly come here for use with a fixed lower part and a shiftable top. The top is over Hydraulic cylinder closed or opened. In terms of control the holding press is designed so that during of the hydroforming process over a long period of time holds. The cylinders must correspond to the opening stroke run all the way. This results accordingly high cycle times. Since the closing force in the hydroforming process is relatively large a very complex hydraulic system is also required.

Furthermore, presses belong to the prior art, in which the mold is mechanically locked. Due to the effect of hydraulic forming Forces and the resulting reaction forces the side stand of the Press frame come with the result that the molding tool opens. This causes the hollow body to the deformation in the parting plane between the lower part and Upper part is not held in a form-fitting manner adversely affects the quality of the formed product. As a result, repositioning the mold necessary during the forming process, but this is the case with the known ones No pressing at all or only through a complex construction can be realized.

The invention is therefore based on the prior art the task of a device for hydraulic To create metal hollow bodies that with simple means a quick and precise Closing process of the mold with sufficiently large opening strokes guaranteed and a more economical hydroforming process enables.

According to the invention, this object is achieved in the features of claim 1.

The core idea of the invention is a device whose Lower part from an open position to a closed position vertically guided is displaceable, the lower part in the closed position can be locked by a locking body and the upper part hydraulically against the Lower part is pressed.

The locking body can be made in one or more parts be.

For inserting a hollow body to be formed the lower part in the open position. Even the locking body is opened. After inserting the hollow body the mold is moved together. this happens by means of a lifting table operated by a hydraulic cylinder is shifted.

The lower part comes into the closed position with the Upper part and is locked here by the locking body. Then the upper part is hydraulically pressed against the lower part pressed. The stroke performed is very great small. During the hydroforming process that is then carried out the mold is clamped between mechanical Down support and hydraulic support up.

In the event of any longitudinal expansion in the side stands the press frame is immediately automatic Repositioning the hydraulically supported upper part. A This makes it impossible to open or move the mold. This ensures a precise forming process. The device according to the invention is also distinguished due to short cycle times. The lifting cylinder of the lower part does not have to apply any forming or deforming forces. The locking cylinders of the upper part form a hydraulic one Support and must be in the case of a longitudinal expansion in Just add the press frame. The hydraulic system can accordingly be carried out more easily and cost-effectively become.

According to the features of claim 2, the top is over a hydraulic cushion is supported on the press frame. This comprises at least one hydraulically acting piston-cylinder unit (Claim 3). In practice, the Use of two piston-cylinder units.

For moving the locking body into its locking position this is according to the features of claim 4 swiveling.

The alternative according to claim 5 provides that the Locking body translationally in its locking position is relocatable.

Figur 1

in perspektivischer Darstellung eine erste Ausführungsform einer erfindungsegemäßen Vorrichtung;

Figur 2

ebenfalls in perspektivischer Darstellungsweise eine zweite Ausführungsform der erfindungsgemäßen Vorrichtung und

Figur 3

teilweise im vertikalen Querschnitt einen Ausschnitt aus einem Pressenrahmen mit der Darstellung eines Hydraulikkissens.

The invention is explained in more detail below on the basis of exemplary embodiments schematically illustrated in the drawings. Show it:

Figure 1

a perspective view of a first embodiment of a device according to the invention;

Figure 2

likewise in perspective representation a second embodiment of the device according to the invention and

Figure 3

partly in vertical cross section a section of a press frame with the representation of a hydraulic cushion.

Corresponding components are shown in FIGS. 1 and 2 the same reference numerals.

Figure 1 shows a device for hydraulic forming of metallic hollow bodies. The device comprises a press frame mounted in a fixed position on floor supports 1 2. The press frame 2 is from a front Frame plate 3 and a rear frame plate 4 formed, which incorporates an upper cross member 5 and a lower cross member 6 braced against each other are.

A molding tool 7 is arranged in the press frame 2. The Mold 7 is divided into two parts with a lower part 8 and an upper part 9.

The lower part 8 is in an open position The closed position can be moved vertically. In the figure 1 shows the closed position.

The lower part 8 is moved by a lifting table 10, the hydraulic upwards via a lifting cylinder 11 or can be moved down. At 12 there is one Guide rod of the lifting table 10 designated.

The upper part 9 is supported indirectly on the press frame 2 movable from. For this purpose, the upper part 9 is on a hydraulic cushion 13 attached. The hydraulic cushion 13 is from two hydraulically acting here indicated schematically Piston-cylinder units 14, 15 are formed. These are with their cylinders on the upper part 9 and with their pistons on upper cross member 5 set. The bottom of the cylinder is designed as a platen.

After inserting a hollow body to be formed the lower part 8 from the open position to the closed position raised by the lifting table 10. The hydraulic cushion 13 is depressurized.

After reaching the closed position, the lower part 8 locked by a locking body 16.

The locking body consists of a unit of two locking blocks 17 and 18, which each have a lever arm 19, 20 attacking hydraulic cylinders 21, 22 um a pivot bearing 23, 24 are pivotable.

In the representation of Figure 1 is in Left locking block 17 in the locking position below the lifting table 10, whereas the right blocking block 18 is shown swung out.

After the mold 7 is closed, the Hydraulic cushion 13 pressurized. This will the upper part 9 hydraulically locked against the mechanically Lower part 8 pressed. The executed stroke of the upper part 9 is small here. The hydroforming process then takes place. This is during the forming process Hydraulic cushion 13 pressurized, so that an automatic Repositioning the upper part 9 in a possible Elongation of the side stands 25, 26 of the press frame 2 is done. A gap or an offset in the mold 7 is thereby avoided.

After completing the hydroforming process, the Mold 7 opened. For this purpose, the blocking body 16 the lifting table 10 freely by pivoting the locking blocks 17, 18. At the same time, the hydraulic cushion 13 relieved of pressure. Lift table 10 and lower part 8 are lowered, whereupon the formed product is taken and further processed can be supplied.

The device shown in Figure 2 corresponds from the basic structure of that of Figure 1. In difference to the above-described embodiment is a Blocking body 27 is provided, which is translational, that is, in a linear movement is shiftable.

The locking body 27 comprises a one-piece locking block 28 with recesses 29 for carrying out the piston rod of Lift cylinder 11 or the guide rods 12 (see FIG 1).

After the lower part 8 together with the lifting table 10 Has reached the closed position, the locking body 27 with With the help of hydraulic cylinders 30, which on stop arms 31, 32 of the locking block 28 attack on a horizontal Slide track 33 under the lifting table 10. As a result, the lower part 8 is locked and mechanically supported. The hydraulic support of the upper part 9 and the forming process takes place in the same way as for the above-described device according to FIG. 1.

The formation of a hydraulic cushion is shown in FIG 34 explained in more detail.

The hydraulic cushion 34 comprises a piston-cylinder unit 35 with two pistons 36, 36 'and a common cylinder 37. The pistons 36, 36 'and the cylinder 37 are on vertical columns 38, 38 'out. The cylinder 37 is on Upper part 39 of a tool set, whereas the Pistons 36, 36 'on the upper cross member 40 of a press frame issue. Are on the top of the cross member 40 the columns 38, 38 'held in bearing components 41, 41'. End of the columns 38, 38 'are stroke limiters 42, 42' intended.

In between the pistons 36, 36 'and the cylinder 37 trained cylinder spaces 43, 43 'is located Hydraulic fluid 44. The cylinder spaces 43, 43 'stand in contact with one another via a connecting bore 45.

This ensures pressure equalization. At 46 is a connection to a control valve. Of the The stroke of the hydraulic cushion 34 is illustrated by the arrow A.

The hydraulic cushion 34 is pressurized during the forming process. With a possible longitudinal expansion of the side stand guaranteed of the press frame, not shown here the hydraulic cushion 34 an automatic Repositioning the upper part 39. As a result, gap formation or an offset in the mold is avoided.

List of reference symbols

1 -

Shelf support

2 -

Press frame

3 -

front frame plate

4 -

rear frame plate

5 -

upper cross member

6 -

lower cross member

7 -

Molding tool

8th -

Lower part of 7

9 -

Top v. 7

10 -

Lift table

11 -

Lifting cylinder

12 -

Guide rods

13 -

Hydraulic cushion

14 -

Piston-cylinder unit

15 -

Piston-cylinder unit

16 -

Blocking body

17 -

Lock block

18 -

Lock block

19 -

Lever arm

20 -

Lever arm

21 -

Hydraulic cylinder

22 -

Hydraulic cylinder

23 -

Pivot bearing

24 -

Pivot bearing

25 -

Side stand

26 -

Side stand

27 -

Blocking body

28 -

Lock block

29 -

Recess

30 -

Hydraulic cylinder

31 -

Stop arm

32 -

Stop arm

33 -

Guideway

34 -

Hydraulic cushion

35 -

Piston-cylinder unit

36 -

piston
36 'piston

37 -

cylinder

38 -

pillar
38 'column

39 -

Top

40 -

Cross member

41 -

Bearing component
41 '- bearing component

42 -

Stroke limiter
42 'stroke limiter

43 -

Cylinder space
43 '- cylinder space

44 -

Hydraulic fluid

45 -

Connecting hole

46 -

connection

H -

Stroke

Claims (5)

Device for the hydraulic forming of metallic Hollow bodies, which one in a press frame (2) arranged mold (7) has a vertically from an open position to a closed position guided displaceable lower part (8) and one movably supported upper part (9, 39), the Lower part (8) in the closed position by a Locking body (16, 27) can be locked and the upper part (9, 39) can be pressed hydraulically against the lower part (8) is. Device according to claim 1, characterized in that the upper part (9, 39) is supported on the press frame (2) via a hydraulic cushion (13, 34). Device according to claim 2, characterized in that the hydraulic cushion (13, 34) comprises at least one piston-cylinder unit (14, 15, 35). Apparatus according to claim 1 or 2, characterized in that the locking body (16) is pivotable. Device according to claim 1 or 2, characterized in that the locking body (27) is translationally displaceable.

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