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 for producing a work piece, comprising: a tool block on a press table having at least two dies for receiving the work piece; a transfer system for transferring the work piece between the at least two dies; at least two upper tools installed on a ram head and at least two lower tools installed on a ram foot, wherein the ram head is rigidly connected to the ram foot to form a ram; wherein: in a first forming step, the work piece is reshaped by one of the at least two upper tools in one of the at least two dies; in a first demoulding step, the work piece is removed from the one of the at least two dies by one of the at least two lower tools; in a transfer step, the work piece is aligned by the transfer system to another one of the at least two dies; in a second forming step, the work piece is reshaped by another one of the at least two upper tools in another one of the at least two dies; and in a second demoulding step, the work piece is removed from the another one of the at least two dies by another one of the at least two lower tools.

2. The transfer press according to claim 1, wherein the ram head and the ram foot by means of two side parts are rigidly interconnected.

3. The transfer press according to claim 2, wherein the ram head, the ram foot and the press table are present in one plane and the side parts have a C-shape, so that the side parts are guided from the ram head to the ram foot in front of or behind the press table.

4. The transfer press according to claim 2, wherein each of the side parts of the ram has a key for displacing the ram head and/or the ram foot in depth, and a pivot point about which the ram head and/or the ram foot around a horizontal axis.

5. The transfer press according to claim 1, wherein a ratio of a width to a height of the ram is 1 to at least 0.5.

6. The transfer press according to claim 1, wherein the transfer press has a central drive motor as a starting point of a drive train, which controls a movement of the ram via at least one connecting rod.

7. The transfer press according to claim 6, wherein two connecting rods on the ram head are installed and transmit a movement of the drive train to the ram.

8. The transfer press according to claim 1, wherein the ram head and the ram foot are guided in a press frame by means of linear bearings.

9. The transfer press according to claim 8, wherein the linear bearings are roller circulating units.

10. The transfer press according to claim 1, wherein the transfer press comprises four linear bearings which each guide the ram head and the ram foot laterally in a press frame.

11. The transfer press according to claim 1, wherein the ram is adjustable without backlash in a press frame by means of lateral wedge adjustments.

12. The transfer press according to claim 1, wherein the transfer system comprises a swing body.

13. The transfer press according to claim 1, wherein the transfer press comprises at least two groups with at least two upper tools and at least two groups with at least two lower tools that are aligned therewith, so that the transfer press can process work pieces in at least two tracks simultaneously.

14. The transfer press according to claim 1, wherein the transfer press is capable of forming bowl-shaped work pieces made of sheet metal.

15. A method for using a transfer press according to claim 1 for forming cup-shaped work pieces made of sheet metal, comprising: a first forming step, wherein the work piece is formed by one of the at least two upper tools; a first demoulding step, wherein the work piece is demoulded from the the one of the at least two dies by the one of the at least two lower tools; a transfer step, wherein the work piece is aligned by the transfer system toward another one of the at least two dies; a second forming step, wherein the work piece is formed in the another one of the at least two dies by another one of the at least two upper tools in the another one of the at least two dies; and a second demoulding step, wherein the work piece is demoulded from the another one of the at least two dies by another one of the at least two lower tools.

16. A method of making cartridge cases comprising utilizing the transfer press according to the claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 Schematic 3D front view of a preferred embodiment of the transfer press for the representation of the ram

(2) FIG. 2 Schematic sectional view of a preferred embodiment of the transfer press in the plane of forming the work pieces

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

(4) FIGS. 4a, 4b Schematic front and side sectional views and FIG. 4c an end view of a preferred embodiment of the transfer press to illustrate the alignment of the ram head to the ram foot.

(5) FIG. 5 Schematic representation of a preferred embodiment of the transfer system of the transfer press

DETAILED DESCRIPTION OF THE PICTURES

(6) 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.

(7) 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.

(8) 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.

(9) 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.

(10) 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.

(11) 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.

(12) 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.

(13) The orientation of the ram main and tappet foot 5 and 7 is illustrated in FIGS. 4a, 4b and 4c. FIG. 4a is a front sectional view, FIG. 4b is a side view and FIG. 4c is an end 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 4b, the lower tools 3 can thereby be aligned concentrically with the dies and upper tools 1.

(14) FIGS. 5a and 5b shows, respectively, side and top views of 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 trans-ported 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

(15) 1 upper tools 3 lower tools 5 ram head (ram main) 7 ram foot (ram base) 9 side parts 11 press table 13 tool block 15 press frame 17 wedge adjustments 19 roller circulation units 21 connection rods 23 transfer system 25 crankshaft 29 feather key 31 die 33 bolt 35 swing body 37 servomotors 39 eccentric 41 gripper jaws