TRANSFER PRESS HAVING A C-SHAPED RAM

Abstract

The invention relates to a transfer press for successive forming and demoulding of work pieces by means of upper and lower tools in dies, wherein the upper tools are attached to a ram head, while the lower tools are installed on a ram foot. The ram head and the ram base are rigidly connected to each other and form a ram.

Claims

1. A transfer press for carrying out at least two forming and demoulding steps at a work piece, comprising a tool block (13) on a press table (11) having at least two dies (31) for receiving the work piece, a transfer system (23) for transferring the work piece between the dies (31), and at least two upper tools (1) and at least two lower tools (3) that can perform relative movement to the press table (11), so that in a first forming step, the work piece can be reshaped by a first upper tool (1) in a first die (31), in a first demoulding step, the work piece can be removed from the die (31) by a first lower tool (3), in a transfer step, the work piece can be aligned by the transfer system (23) to a second die (31), in a second forming step, the work piece can be reshaped by a second upper tool (1) in the second die (31) and in a second demoulding step, the work piece can be removed from the second die (31) by a second lower tool (3) characterised in that the upper tools (1) are installed on a ram head (5), the lower tools (3) are installed on a ram foot (7), and the ram head (5) and the ram base (7) are rigidly connected to one another to form a ram.

2. Transfer press according to claim 1, characterised in that the ram head (5) and the ram base (7) by means of two side parts (9) are rigidly interconnected.

3. Transfer press according to claim 2, characterised in that the ram head (5), the ram foot (7) and the press table (11) are present in one plane and the side parts (9) have a C-shape, so that the side parts (9) are guided from the ram head (5) to the ram base (7) in front of or behind the press table (11)

4. Transfer press according to claim 1, characterised in that the ratio of the width to the height of the ram is 1 to at least 0.5, preferably 1 to at least 1.

5. Transfer press according to claim 1, characterised in that the transfer press has a central drive motor as a starting point of a drive train, which controls the movement of the ram via at least one connecting rod (21).

6. Transfer press according to claim 5, characterised in that two connecting rods (21) on the ram main (5) are installed and transmit the movement of the drive train to the ram.

7. Transfer press according to claim 1, characterised in that the ram head (5) and the ram base (7) are guided in a press frame (15) by means of linear bearing points.

8. Transfer press according to claim 7, characterised in that the linear bearings are roller circulating units (19) and/or hydrodynamic plain bearings.

9. Transfer press according to claim 1, characterised in that the transfer press comprises four linear bearing points which each guide the ram head (5) and the ram foot (7) laterally in a press frame (15).

10. Transfer press according to claim 1, characterised in that the ram is adjustable without backlash in a press frame (15) by means of lateral wedge adjustments (17).

11. Transfer press according to claim 2, characterised in that each side part (9) of the ram has a key (29) for displacing the ram head (5) and/or the ram base (7) in the depth, and a pivot point (33) for rotating the ram head (5) and/or the ram base (7) around a horizontal axis.

12. Transfer press according to claim 1, characterised in that the transfer system (23) comprises a swing body (35).

13. Transfer press according to claim 1, characterised in that the transfer press comprises at least two groups with at least two, preferably at least four, upper tools (1) as well as at least two groups with at least two, preferably at least four, lower tools (3) that are aligned therewith, so that the transfer press can process work pieces in at least two tracks simultaneously.

14. Transfer press according to claim 1, characterised in that the transfer press is suitable for forming bowl-shaped work pieces made of sheet metal, particularly preferably for the production of cartridge cases.

15. A method for using of a transfer press according to claim 1 for forming bowl-shaped work pieces made of sheet metal, preferably for the production of cartridge cases.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0052] FIG. 1 Schematic 3D front view of a preferred embodiment of the transfer press for the representation of the ram

[0053] FIG. 2 Schematic sectional view of a preferred embodiment of the transfer press in the plane of forming the work pieces

[0054] FIG. 3 Schematic sectional view of a preferred embodiment of the rolling circulating units and feather keys for attachment of the ram head

[0055] FIG. 4a, b Schematic sectional views of a preferred embodiment of the transfer press to illustrate the alignment of the ram head to the ram foot

[0056] FIG. 5 Schematic representation of a preferred embodiment of the transfer system of the transfer press

DETAILED DESCRIPTION OF THE PICTURES

[0057] FIG. 1 shows a schematic 3D front view of a preferred embodiment of the transfer press for the representation of the ram. The preferred transfer press is used for forming cup-shaped work pieces made of sheet metal. For this purpose, the transfer press comprises upper tools 1 and lower tools 3. In the preferred embodiment shown, the transfer press has two tracks for processing the work pieces. The left and right lanes each comprise five upper tools or drawing punches 1, as well as five lower tools or demoulding dies 3, which are aligned therewith. By a downward movement of the upper tools 1, the work pieces are reshaped or drawn into dies. An upward movement of the lower punch 3 ensures removal of the work pieces from the dies. The dies (not visible) are for the purpose of forming in a tool block 13 on the press table 11. Transport of the work pieces from one die to the next takes place by means of a transfer system 23.

[0058] During operation of the transfer press clocked movement of the upper tools 1 takes place downwards for forming, and for the lower tools 3 upwards for demoulding. Between these steps, the transfer system 23 each oscillates between two positions to ensure further transport of the work pieces.

[0059] A ram implements the common vertical relative movement of the upper and lower tools 1 and 3 to the press table 11. The ram comprises a ram head 5 for attachment of the upper tools 1 and a ram base 7 for fixing the lower tools 3. Two side parts 9 rigidly connect the ram head 5 and the ram foot 7 to each other. The ram head 5, the ram foot 7 and the press table 11 are present in one plane, whereas the side parts 9 are guided from the tappet head 5 to the tappet foot 7. In the side view of the transfer press, the side parts 9 therefore have a corresponding C-shape.

[0060] The drive of the moulded ram is accomplished via two connecting rods 21 by means of a crankshaft 25, wherein the connecting rods 21 preferably attack each track in the centre of gravity to ensure a stable power transmission. The ram is movably supported in the press frame 15 by means of four lateral roller circulation units 19 in order to allow a precise vertical guidance. Two one-sided wedge adjustments 17 effect lateral fitting of the ram in the guide frame of the press frame 15.

[0061] Advantageously, the ram may be driven via a single drive motor (not shown) that transmits the movement to the crankshaft 25 via, for example, a belt transmission, a flywheel, a clutch brake combination, and a planetary gear. Separate control of the upper and lower tools 1, 3 is not necessary because the ram head 5 is rigidly connected by means of the side parts 9 with the tappet foot 7.

[0062] FIG. 2 shows a schematic sectional view of a preferred embodiment of the transfer press in the plane of forming the work pieces. In the sectional view it can be seen that the ram main 5 is present on the left side via wedge adjustments 17 on the frame 15. The same applies to the tappet foot 7. This allows a particularly simple fitting to be implemented. Roller circulation units 19 effect the vertically guided movement of the ram in the press frame 15.

[0063] FIG. 3 shows a detailed view of the roller circulation units 19 and the key 29. By means of the key 29. the ram head 5 can be moved in the depth of the transfer press, forward and backward, relative to the ram foot 7.

[0064] The orientation of the ram main and tappet foot 5 and 7 is illustrated in FIG. 4a, b. FIG. 4a is a front sectional view, and FIG. 4b is a side view. Through the use of two left-side wedge adjustments 17, a lateral displacement of the ram head 5 and the ram foot 7 is possible. Here, by a vertical displacement of the wedges of the wedge adjustment 17 their width is adjusted, so that the ram is fitted without play in the lateral frame of the press frame 15. The feather key 29 allows an adjustment of the ram head 5 in depth relative to the ram foot 7. In addition, the bolt 33 allows tilting of the ram foot 7, and thus the lower tools 3, about a horizontal axis. As illustrated in the side view 6b, the lower tools 3 can thereby be aligned concentrically with the dies and upper tools 1.

[0065] FIG. 5 shows a schematic representation of a preferred embodiment of the transfer system 23 of the transfer press. This comprises a swing body 35 with gripper jaws 41 for receiving the work pieces. After forming, a work piece is removed from the dies by an upward movement of the ram by means of the lower tools 3. In this case, it is preferable for the work pieces to be pushed into gripper jaws 41 of the swing body 35. With the aid of servomotors 37 and eccentrics 39, the swing body 35 can be oscillated between two positions during the operation of the transfer press. After the demoulding step and before the next forming step, the work pieces are present in the swing body and are transported by a transfer step from the first to the second position (pre-swinging). After the forming step and before the next demoulding step, the swing body swings back without work pieces from the second to the first position. The sequence of processing steps is thus carried out in a way that there is always a transport of the work pieces in the transfer direction.

LIST OF REFERENCE NUMBERS

[0066] 1 upper tools [0067] 3 lower tools [0068] 5 ram head (ram main) [0069] 7 ram foot (ram base) [0070] 9 side parts [0071] 11 press table [0072] 13 tool block [0073] 15 press frame [0074] 17 wedge adjustments [0075] 19 roller circulation units [0076] 21 connection rods [0077] 23 transfer system [0078] 25 crankshaft [0079] 29 feather key [0080] 31 die [0081] 33 bolt [0082] 35 swing body [0083] 37 servomotors [0084] 39 eccentric [0085] 41 gripper jaws