Press having at least two eccentric shafts

Abstract

The invention relates to a press or an automatic punching press (1) having at least one drive (10, 11, 12, 13) and at least two eccentric shafts (5, 6, 7, 8) which are disposed in a head piece (9) of the press (1) and drive at least one ram (2, 19) via connecting rods (3, 3', 4, 4'). According to the invention, the two eccentric shafts (5, 6, 7, 8) are positioned perpendicularly to one another.

Description

[0001] PRESS WITH AT LEAST TWO ECCENTRIC SHAFTS

[0002] The subject of this invention is a press or a punching machine with at least one drive and at least two eccentric shafts which drive at least one ram in an oscillating manner via connecting rods.

[0003] Very precise presses with high pressing forces are required especially for the production of bipolar plates for hydrogen production and for the production of electrical steel sheets. For bipolar plates, very fine channels are embossed and recesses are punched out of relatively thin sheets. This requires, on the one hand, very high pressing forces in the range of 1500 to 2000 tons, and on the other hand, the pressing must be as even as possible across the entire surface of the sheet so that the channels have a uniform depth. This requires correspondingly large and precise presses. In conventional presses with an eccentric shaft and two connecting rods, the ram is secured against tilting in the x-direction by the two pressure points of the connecting rods. However, here tilting of the ram perpendicular to this, i.e. in the y-direction, can only be prevented by the ram guide.However, the ram guide can only prevent this tilting to a limited extent, which then leads to problems for very precise applications. Presses with two eccentric shafts are already known. DE 101 39 029 C5, for example, describes a press with two parallel eccentric shafts, several connecting rods and several drives. The ram moves back and forth between a bottom and a top dead center. In these machines, the pressing or punching force is transmitted to the ram via four connecting rods (4-point press). As the four pressing points form a rectangle, tilting in the y-direction can also be prevented. However, the arrangement of two parallel eccentric shafts also has disadvantages. The space between the eccentric shafts is very limited, which restricts the movement space for the connecting rods and therefore also the stroke.

[0004] The invention is based on the object of providing a press or a punching machine in which the punching or forming process is improved and can thus be carried out very precisely.

[0005] This object is achieved by a press or automatic punching machine with at least two eccentric shafts arranged in the head of the press and driving at least one ram via several connecting rods. According to the invention, the at least two eccentric shafts are arranged perpendicular to one another. The two eccentric shafts are therefore perpendicular to one another.

[0006] With this arrangement there is enough space for the drives and the movement space for the connecting rods is hardly restricted.

[0007] In addition, this arrangement ensures that the forming and cutting forces are transferred particularly evenly from the ram to the head piece.

[0008] This invention enables force to be transmitted to the ram via several pressure points that are not in a line. This prevents the ram from tilting. Due to the more even introduction of force into the ram, it can also be designed to be less rigid. In one possible embodiment of the invention, exactly two eccentric shafts are arranged crosswise in the head piece of the press or automatic punching machine. The two eccentric shafts are then arranged one above the other, viewed in a horizontal plane.

[0009] Each eccentric shaft can then, for example, drive two connecting rods.

[0010] However, it is also conceivable for three eccentric shafts to be arranged in the headpiece of the press, with the first and third eccentric shafts arranged one behind the other on a common axis, and this axis being perpendicular to the second eccentric shaft. In this case, one of the eccentric shafts is essentially split in the middle, allowing the other eccentric shaft to pass through this free space. With this arrangement, all three eccentric shafts can be arranged in the same horizontal plane.

[0011] It can also be useful if four eccentric shafts are arranged in the head piece, with two of these eccentric shafts being arranged one behind the other on a common axis and with these axes being perpendicular to one another.

[0012] It is advantageous if each eccentric shaft has its own drive. This could be, for example, a servo drive or a conventional drive connected to the eccentric shaft via a single-stage or two-stage planetary gear. It is advantageous if the intersection point of the two continuous eccentric shafts is located centrally above the tappet center. Similarly, in the case of split eccentric shafts, it is advantageous if the intersection point of their rotational axes is located centrally above the tappet center.

[0013] It is also conceivable for at least one eccentric shaft to drive two connecting rods mounted on it, whereby these two connecting rods can then be connected to each other at the end facing the tappet. This lower end can be connected to the tappet via one press point or via several press points.

[0014] It is advantageous if all connecting rods of the press are of equal length. Since the eccentric shafts do not have to be arranged in the same horizontal plane, but can be spaced vertically, the attachment points on the ram are also vertically spaced accordingly for connecting rods of equal length.

[0015] It is also conceivable that at least one eccentric shaft drives a first tappet and that a second eccentric shaft, which is arranged perpendicular to the first eccentric shaft, drives a second tappet, which is preferably arranged in the first tappet.

[0016] Several embodiments of the invention are described below with reference to drawings. They show:

[0017] Fig . 1 is a schematic side view of a

[0018] Embodiment of the press according to the invention; Fig. 2 is a detailed view of the headpiece of the press from Figure 1;

[0019] Fig. 3 is a schematic side view of a headpiece;

[0020] Fig. 4 is a plan view of the headpiece of Fig. 3;

[0021] Fig. 5 to Fig. 8 a plan view of the plunger with different arrangement of the pressure points;

[0022] Fig. 9 to Fig. 11 different designs of the connecting rods;

[0023] Fig. 12 and 13 different drive concepts for a press according to the invention with two eccentric shafts;

[0024] Fig. 14 and 15 different drive concepts for a press according to the invention with three eccentric shafts;

[0025] Fig. 16 different drive concepts for a press according to the invention with four eccentric shafts;

[0026] The same reference symbols in the respective figures refer to the same components.

[0027] Figure 1 shows, by way of example, a press 1 with a press frame 30, side uprights, and a headpiece 9. In this example, two eccentric shafts 5 and 6 are rotatably mounted in the headpiece 9. The two eccentric shafts 5, 6 are perpendicular to one another and are not located in the same horizontal plane 14. The first eccentric shaft 5 is located in the horizontal plane 14, and the second eccentric shaft 6 is located in the horizontal plane 14', which is vertically spaced from the first horizontal plane 14.

[0028] Two eccentric bushings are arranged for each eccentric shaft 5, 6, on each of which the upper end 24 of the connecting rod 3, 3', 4, 4' is rotatably mounted via a roller bearing or plain bearing.

[0029] The first eccentric shaft 5 drives the two connecting rods 3 and 3 ' and the second eccentric shaft 6 drives the two connecting rods 4 and 4 '.

[0030] At the lower end 23, the four connecting rods 3, 3', 4, 4' are connected to the tappet 2 via ball screws 22.

[0031] Figure 2 shows a perspective view of the head piece 9 from Figure 1. Here you can clearly see the bearing of the connecting rods

[0032] 3, 3', 4, 4' on the two eccentric shafts 5, 6, which are arranged one above the other in the headpiece 9 and are perpendicular to each other when viewed from above. The first eccentric shaft 5 is driven by two oppositely arranged drives 10 and 13. The second eccentric shaft 6 is driven by drive 11.

[0033] A side view and a top view of the head piece 9 are also shown in Figures 3 and 4. The reference numerals 25 and 26 denote the axes of the two eccentric shafts 5 and 6; they intersect at the intersection point 15, which is generally located centrally above the tappet 2.

[0034] You can also see the recesses 28 for the connecting rods 3, 3',

[0035] 4, 4 ' in the headpiece 9.

[0036] Figures 5 to 8 each show a top view of the

[0037] Ram 2, showing the pressure points 27 of the respective connecting rods. In such presses, ram 2 can, for example, have a length of 3 m to 7 m and a width of 1 to 3 m.

[0038] Figure 5 shows a four-point press. Two connecting rods are arranged per eccentric shaft axis 25, 26. The two connecting rods 4, 4' per eccentric axis 25,

[0039] 26 can be designed as shown in Figure 10. In these examples, each eccentric shaft axis 25, 26 can be formed by an eccentric shaft 5, 6 or by split eccentric shafts 5, 6, 7, 8, as described in the following figures.

[0040] Figure 6 shows a plan view of the tappet 2 with 5 pressure points 27. The three pressure points 27, which are located below the eccentric shaft axis 26, can be generated by a connecting rod 4, 4' according to Figure 11.

[0041] Figure 7 shows a top view of the tappet 2 with only three pressure points 27. The pressure point 27 in the center is created by connecting rods 4, 4', which are connected to each other at the lower end and are also supported by the eccentric shaft axis 26. These connecting rods can have the shape of the connecting rods 4, 4' from Figure 9.

[0042] Figure 8 shows a particularly interesting arrangement with two tappets 2 and 19. The two outer pressure points 27 act on the tappet 2 and the inner pressure point 27 acts on the second tappet 19. Here, the second tappet 19 is moved by its own eccentric shaft 6. Whereas the tappet 2 is moved by a continuous eccentric shaft 5 or by a split eccentric shaft 5 or 7. The connecting rod for the middle pressure point

[0043] 27 can have the shape of the connecting rod in Figure 9 or it can also be a simple connecting rod. It is also conceivable for the second tappet to also have several pressure points 27. With this arrangement, there are then two crosswise arranged eccentric shaft axes 25, 26, on each of which one or two eccentric shafts 5, 6, 7, 8 are located. Each axis 25, 26 drives its own tappet 2 or 19. This arrangement allows the tappets 2 and 19 to be moved completely independently of one another. The second tappet 19 can be guided within the first tappet 2. Preferably, the second tappet 19 is located centrally within the first tappet 2, but this is not absolutely necessary.

[0044] Figure 12 shows a press 1 from Figure 1 with different drive concepts. The eccentric shafts 5, 6 can be driven either by one drive 10, 11 each or by two drives 10 and 13 or 11 and 12 each. One eccentric shaft 5 can also be driven by one drive 10 and the second eccentric shaft 6 by two drives 11, 12. The bearing points 20 of the eccentric shafts 5, 6 are indicated by the reference numeral 20. A planetary gear 21 is arranged between the drive motors 10 and 11 and the eccentric shafts 5, 6. The arrangement of the eccentric shafts 5 and 6 is shown in the lower right corner of Figure 12, which are each located in a horizontal plane 14 and 14', wherein the two horizontal planes 14, 14' are spaced apart from one another in the vertical direction.This is necessary here because the intersection point 15 (viewed in plan view) cannot lie in the same horizontal plane 14, 14' with continuous eccentric shafts 5, 6. Figure 13 shows an analogous view to Figure 12, with two gear stages 29 arranged per drive 10, 11, 12, 13.

[0045] Of course, drive concepts without gears can also be provided here, in which, for example, a servo motor directly drives the eccentric shafts 5, 6, 7, 8.

[0046] Figures 14 and 15 show different drive concepts with three eccentric shafts 5, 6, 7. It can be seen here that the original one-piece eccentric shaft 5 has been split and now consists of two separate eccentric shafts 5 and 7. The two eccentric shafts 5 and 7 lie on the common axis (axis of rotation) 17. By dividing and spacing this eccentric shaft 5, 7 in the axial direction, all three eccentric shafts 5, 6, 7 can be arranged in the same horizontal plane 14, as shown in Figure 14 bottom right. However, an arrangement of all eccentric shafts 5, 6, 7, 8 in the same horizontal plane 14 is not absolutely necessary. An arrangement with three eccentric shafts 5, 6, 7 has either three separate drives 10, 11, 13 or, if the continuous eccentric shaft 6 is to be driven on both sides, four separate drives 10, 11, 12, 13.

[0047] The eccentric shafts 5, 6, 7 can be driven by a simple planetary gear 21 or by two gear stages 29.

[0048] Figure 16 shows an arrangement with four separate eccentric shafts 5, 6, 7, 8. Two eccentric shafts 5 and 7 or 6 and 8 are located on a common axis 17 and 18. The two axes 17 and 18 are perpendicular to each other. Each eccentric shaft 5, 6, 7, 8 has its own drive 10, 11, 12, 13.

[0049] A planetary gear 21 or two gear stages 29 may be interposed. All four eccentric shafts 5, 6, 7, 8 can be arranged in a common horizontal plane 14.

[0050] Reference symbol

[0051] 1 press

[0052] 2 pestles

[0053] 3 , 3 ' connecting rod

[0054] 4 , 4 ' connecting rod

[0055] 5 first eccentric shaft

[0056] 6 second eccentric shaft

[0057] 7 third eccentric shaft

[0058] 8 fourth eccentric shaft

[0059] 9 Headpiece

[0060] 10 first drive

[0061] 11 second drive

[0062] 12 third drive

[0063] 13 fourth drive

[0064] 14, 14 ' horizontal planes

[0065] 15 Intersection point

[0066] 16 Tappet center

[0067] 17 common (rotational) axis of the two eccentric shafts

[0068] 5 and 7

[0069] 18 common (rotational) axis of the two eccentric shafts

[0070] 6 and 8

[0071] 19 second plunger

[0072] 20 storage location

[0073] 21 planetary gears

[0074] 22 ball screw

[0075] 23 lower connecting rod end

[0076] 24 upper connecting rod end

[0077] 25 Axis of the first eccentric shaft (n)

[0078] 26 Axis of the second eccentric shaft (n)

[0079] 27 pressure points

[0080] 28 recesses

[0081] 29 two gear stages

[0082] 30 press frame

Claims

Patent claims 1. Press or punching machine (1) with at least one drive (10, 11, 12, 13) with at least two eccentric shafts (5, 6, 7, 8) which are arranged in a head piece (9) of the press (1) and which drive at least one ram (2, 19) via connecting rods (3, 3', 4, 4'), characterized in that the at least two eccentric shafts (5, 6, 7, 8) are arranged perpendicular to one another.

2. Press or punching machine (1) according to claim 1, characterized in that exactly two eccentric shafts (5, 6) are arranged crosswise in the head piece (9).

3. Press or punching machine (1) according to claim 2, characterized in that the two eccentric shafts (5, 6) are arranged one above the other when viewed in a horizontal plane (14, 14').

4. Press or punching machine (1) according to claim 2 or 3, characterized in that each of the two eccentric shafts (5, 6) drives two connecting rods (3, 3', 4, 4').

5. Press or punching machine (1) according to claim 1, characterized in that three eccentric shafts (5, 6, 7) are arranged in the head piece (9), wherein the first and the third eccentric shaft (5, 7) are arranged one behind the other on a common axis (17) and wherein this axis (17) is perpendicular to the second eccentric shaft (6).

6. Press or punching machine (1) according to claim 5, characterized in that the three eccentric shafts (5, 6, 7) are arranged in the same horizontal plane (14).

7. Press or punching machine (1) according to claim 1, characterized in that four eccentric shafts (5, 6, 7, 8) are arranged in the head piece (9), two of these eccentric shafts (5 and 7, 6 and 8) being arranged one behind the other on a common axis (17, 18) and these axes (17, 18) being perpendicular to one another.

8. Press or punching machine (1) according to claim 7, characterized in that the four eccentric shafts (5, 6, 7, 8) are arranged in the same horizontal plane (14).

9. Press or punching machine (1) according to one of claims 1 to 8, characterized in that each eccentric shaft (5, 6, 7, 8) has its own drive (10, 11, 12, 13).

10. Press or punching machine (1) according to one of the claims 1 to 9, characterized in that the crossing point (15) of the eccentric shafts (5, 6) or the axes (17, 18) of the eccentric shafts (5, 6, 7, 8) are located centrally above the tappet center (16).

11. Press or punching machine (1) according to one of claims 1 to 10, characterized in that at least one eccentric shaft (5, 6, 7, 8) drives two connecting rods (4, 4') mounted on this eccentric shaft, the two connecting rods (4, 4') being connected to one another at their end (23) facing the ram (2). Press or automatic punching machine (1) according to one of claims 1 to 11, characterized in that all connecting rods (3, 3', 4, 4') are of equal length. Press or automatic punching machine (1) according to one of claims 1 to 12, characterized in that at least one eccentric shaft (5, 6, 7, 8) drives a first ram (2), and a second eccentric shaft (5, 6, 7, 8) drives a second ram (19) arranged in the first ram (2).

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