Press for high-speed cutting function, inherent minimization of cutting impact, and cost-effective press force extension by means of an impulse drive acting directly on the press ram and optimally adapted to the forming process.

Abstract

Press for high-speed cutting, inherent minimization of cutting impact, and cost-effective press force extension by means of an impulse drive acting directly on the press ram and optimally adapted to the forming process. The invention relates to presses for processing metallic workpieces, in particular presses with a press ram moved by mechanical drives. According to the invention, in addition to the force applied by known mechanical drives present in the press, the press ram experiences an impulse-controlled force extension that is optimally adapted to the forming process. For this purpose, an impulse drive 27, preferably a hydraulic impulse cylinder 1, is assigned to the press ram. Preferably, the impulse cylinder 1 is located directly in the press ram. This transmits an optimal force impulse to the press ram.Preferably, the impulse transmission begins after the known press drive has applied a minimum force, for example, 40% of the maximum force. The characteristics of the impulse transmission can be optimally adapted to the respective forming process by means of an impulse forming cylinder 7 arranged between the impulse piston 2 of the impulse cylinder 1 and the ram. The parameters of this cylinder optimally adapt the force impulse transmitted between the impulse cylinder 1 and the press ram to the forming process. The complex determination of the best possible parameters for the impulse forming cylinder 7 for the respective forming process, as well as the optimal values ​​for the impulse cylinder 1, can be quickly found using an existing simulation program.

Description

[0001] The invention has the following tasks: 1 To extend known mechanical press drives so that a partial increase in the shear rate when separating metal in the final phase of the forming process is achieved in order to improve the cutting quality. 2 To significantly reduce the maximum force required by existing drives for forming processes with short forming strokes such as cutting or stamping. 3 drastically reduce stress relief strokes during shear cutting on larger presses. Fig. Figure 4 provides an example of this, demonstrating the virtually complete reduction of the connecting rod force of a crank press at the end of a sheet metal cutting process. This inevitably leads to a significant reduction in the press's relaxation strokes and cutting strokes.

[0002] The following are known from the sponsorship literature: 1 Devices for increasing the shear rate when cutting metal to improve the cutting quality 2 elements for dampening the relaxation shock of the press when shearing metal 3 combinations of different drives in one press

[0003] Devices for increasing the shear rate during metal cutting to improve cut quality, where at high shear rates the process heat remains in the immediate shearing area and a significantly better cut surface quality can be achieved due to the higher shear temperature, are known from the following inventions. The devices described relate exclusively to increasing the shear rate. Solutions for simultaneously reducing the maximum force exerted by the drive and for avoiding cutting impact are not specified.

[0004] OS DE 10 2012 019 386 A1 describes a device in which pre-tensioned springs press on toggle levers that are slightly above the extended position. A mechanical movement moves the toggle levers out of the extended position and, due to the spring pre-tension, they move abruptly downward. The disadvantage here is that a large amount of space is required on the press table, particularly because the springs, with their limited force, occupy a large area. Furthermore, the crosshead required to support the springs, due to its own inertia, significantly reduces the desired high speed of the working stroke. This type of device is also more suitable for small-surface workpieces.

[0005] Document DE102019001384A1 describes a precision impact cylinder capable of extending at extremely high speeds. It is ideally suited for making clean cuts, for example, on bar stock. However, when cutting sheet metal, the residual speed after the cutting process leads to a difficult-to-predict plunge of the cutting punch into the die. It is also practically impossible to fully accelerate large-surface tool upper parts, taking into account the required feed stroke. However, it is excellently suited for implementing the impulse cylinder 1 required in the present application, as it does not require large switching valves, thick supply lines, or any external pressure accumulators.

[0006] Combinations of various known drives are also known for jointly carrying out a forming process. For example, hydraulic drives for forming metal are known in which hydraulic drives arranged one behind the other initially apply a medium force over a longer distance, and then another hydraulic impact cylinder takes over the final forming. Examples include DE000002623428 or DE000000209989A. These drives have not been applied to the shear cutting of sheet metal, nor is it sensible; the same problem would arise as with the application of the previously cited patent in document DE102019001384A1: the uncontrolled immersion of punches into the die. The problem of avoiding cutting impact during shear cutting is also not solved.DE102016012803B4, whose actual objective is improved ram guidance, describes the simultaneous drive of the ram both hydraulically and mechanically, each with its own known drive technology. The technical implementation of such drives is expensive and, by combining the respective disadvantages of the drives to the smallest common denominator, only results in lower stroke rates. And it has not yet been realized in this form. The objective of creating a press drive with a high-speed shear-cutting function with inherent cutting impact elimination is not achieved here in any way, but it was also not the objective or objective of the relevant application. DE102011122492 describes a magnetically driven press. To achieve greater force, two drives are combined. The headpiece contains linear motors for the idle stroke and lower forming forces.In the lower section of the press is another drive, also magnetically initiated. This lower drive is designed for greater forces. Due to the inertia of the magnets, high-speed shear-cutting in the 1-millisecond range is not possible. Furthermore, the higher final force is applied via crossheads that act on the upper tool via tie rods. Their expansion at maximum force and subsequent relaxation after the sheet is torn off leads to the well-known cutting impact. DE000002559150 describes a press whose drive is designed for maximum speed during the cutting process through the kinematic coupling of several links. Apart from problems in designing such a drive for high forces due to the complexity of the mechanical links, for example, for a force of 10,000 kN, no inherent cutting impact elimination is achieved.At maximum force before sheet tear, the press also experiences maximum expansion.

[0007] The drive is still only designed for short forming strokes. It is also not suitable for progressive dies with longer force paths, such as those used in deep drawing, so it is not universally applicable.

[0008] The task of effectively supplementing known drives, in particular mechanical drives in presses, in such a way that the ram speed is partially brought in the area of ​​a sheet metal cut to an amount required for high-speed shear cutting, that the maximum force to be applied by known drives for forming processes with short forming paths such as cutting or stamping is significantly reduced, that the press can therefore be designed more cost-effectively overall or can achieve a significantly higher final force for cutting or stamping processes at the same cost and that the maximum elongation of the press before reaching the maximum force is simultaneously reduced or can even be brought to close to zero and in this way the cutting impact is significantly reduced or can even be completely eliminated, is carried out with the solutions specified by the invention according to the claims.

[0009] According to the invention, in addition to the force applied by the known mechanical drives present in the press, the press ram experiences a pulse-controlled force extension that is optimally adapted to the forming process. For this purpose, an impulsion drive consisting of a hydraulic impulse cylinder 1 and an impulse-forming cylinder 7 is assigned to the press ram. The impulsion drive is preferably located directly in the press ram. In principle, it can also be arranged in the headpiece or under the press table. This transmits an optimal force impulse to the press ram. The impulse transmission preferably begins after the known press drive has applied a minimum force, for example, 40% of the maximum force.The pulse transmission characteristics can be optimally adapted to the respective forming process using a pulse-shaping cylinder 7 located between the piston of pulse cylinder 1 and the ram. Its parameters optimally adapt the force pulse transmitted between pulse cylinder 1 and the press ram to the forming process. The complex process of determining the optimal parameters for the pulse-shaping cylinder for the respective forming process can be quickly determined using an existing simulation program. List of reference symbols 1 impulse cylinder 2 impulse pistons 3 Hydraulic supply impulse cylinder 4 storage piston impulse cylinders 5 gas spring cushion impulse cylinder 6 press rams 7 pulse shaping cylinders 8 pistons of the pulse shaping cylinder 9 Oil chamber piston of the pulse forming cylinder 10 Piston travel-dependent outflow area of ​​the pulse shaping cylinder 11 Adjustable outflow area of ​​the pulse shaping cylinder 12 Check valve 13 Small pressure accumulator 14 Gas spring cushion Small pressure accumulator 15 Pressure connection for gas spring cushion Small pressure accumulator 16 Low pressure pump 17 Check valve 18 Throttle 19 oil tanks 20 Pressure branch and pressure measurement overload cylinder 21 overload cylinders 22 connecting rods 23 Crankshaft 24 Drive Press 25 frame press 26 Follow-on tool 27 Impulse drive

[0010] Fig. Figure 1 explains the pulse-controlled force extension on presses, which is optimally adapted to the forming process, using the example of a crank press, in whose press ram 6 an impulse drive 27, here consisting of hydraulic impulse cylinder 1 and impulse forming cylinder 7, is arranged. The impulse cylinder 1 is located directly in the schematically illustrated press ram 6, above the impulse forming cylinder 7. The impulse drive 27 is intended to be used precisely when the connecting rods 22 have already applied a defined minimum force. The design function of the impulse drive 27 is directly related to the implemented technical parameters. Therefore, a brief anticipation of the force curves according to Fig. 4 to illustrate the purpose of the structural elements involved.

[0011] In the diagram Fig. 4, the effect of the impulsive drive begins at a force of 3,000 kN, for example, with a total force required of 10,000 kN to cut a large, thin metal part used in the calculation. Fig. Figure 4 shows that the connecting rod force practically stops increasing after the onset of the impulsive drive. After the onset of the impulsive drive, the connecting rod force decreases as the impulsive drive force increases. While the impulsive force increases to approximately 6000 kN, the connecting rod force drops to practically zero.

[0012] This brings with it considerable advantages. The press can be designed for lower forces overall. This saves a considerable amount of material. When the connecting rod force and thus also the frame force of the press drop to zero towards the end of a cutting process, the dreaded cutting impact, which is associated with considerable noise pollution, is practically non-existent. At first glance, it seems contradictory to say that noise can be eliminated by introducing a defined impact pulse. However, when you consider that the noise during the cutting process is primarily caused by machine vibrations after the abrupt sheet break due to the release of the stored strain energy in the frame, it becomes plausible that the noise can be drastically reduced if the machine vibrations are drastically reduced by effectively bringing the strain force of the machine before the break during a cutting process to zero.

[0013] Another advantage is Fig. 3 can be seen when comparing with the values ​​from Fig. 2. The machine's ram experiences a significant short-term acceleration due to the impulse that the impulse shaping cylinder 7 imparts to the ram. As shown in the diagram there after Fig. 3, the ram speed briefly reaches values ​​that are desired to achieve very clean results in shear cutting [“high-speed shear cutting”]. This is due to the fact that the lateral heat transfer during the simulated cutting process is reduced to the same extent; it is foreseeable that the cutting quality will be significantly improved. The duration of the cutting process simulated in the simulation program according to Fig. 3 is reduced to a time span of the order of 10 to 20% compared to cutting on known presses such as in Fig. 2 determined.

[0014] In summary, this combines inherent process-based avoidance of cutting impact with simultaneous improvement in cutting quality. Furthermore, the design of a press with power amplification through impulsive drive no longer needs to be based on the requirements of conventional drives, but can be significantly more material-efficient.

[0015] The realization of force amplification and ram acceleration by the impulsive drive according to the invention is described below. The signal for triggering the impulse cylinder 1 can, for example, be taken from the oil cushion of the overload cylinder 21 via the pressure branch 20. This can be an electrical signal. However, the direct control of a pressure switching valve with a tiny amount of pressurized oil taken from the oil cushion is also expedient. After the impulse cylinder 1 has been triggered, the impulse piston 2 moves at an extremely high speed toward the piston 8 of the impulse-shaping cylinder 7. The basis of the extremely high speed of the impulse piston 2 is the energy stored in the gas spring cushion 5, which is transferred to the impulse piston 2 by means of the storage piston 4 with virtually no flow losses. The impulse cylinder 1 is not the subject of the invention here.The operation of such a drive is described in DE102019001384 and is therefore not discussed in further detail here. In principle, any drive capable of achieving very high mass acceleration can be used instead of the hydraulic impulse cylinder 1 specified here as an example. However, according to the current state of the art, the hydraulic impulse cylinder specified in DE102019001384 is the most suitable in terms of its realized speed parameters. Furthermore, the hydraulic implementation is possible with little effort, which is a necessary requirement to comply with the limited spatial constraints in the ram 6. Hydraulic systems with complex external accumulators, large valves, and thick hydraulic lines are impractical in this case.

[0016] In the simulation of a 10,000 kN press, a mass of 500 kg was used for the impulse piston 2. The diagrams [ Fig. 3] were calculated with a speed of 8.5 m / sec for the impulse piston 2. The impulse cylinder 1, as described in DE102019001384, can achieve significantly higher speeds. The simulation of the impulse drive in the 10,000 kN press showed that a speed of 8.5 m / sec is optimal for the assumed forming process. Important results of the calculation are explained in the explanation of Fig. 2 to Fig. 4. Due to the diverse design possibilities and for the sake of clarity, the 3D structure of the press ram 6 is not discussed here; a brief schematic representation is provided by marking it with 6. This is especially true since the entire impulsion drive can also be mounted displaceably within the ram in order to set the impulse precisely above a specific center of gravity of the forming force of the follow-on tool 26. Larger presses can also have multiple impulsion drives.

[0017] The function of force amplification by impulsive drive is described below. When the impulse piston 2, accelerated to, for example, 8.5 m / s, hits the piston 8 of the impulse-shaping cylinder 7, a pressure builds up in the oil chamber 9 of the impulse-shaping cylinder 7, which increases the higher the speed and mass of the impulse piston 2. The oil chamber 9 of the impulse-shaping cylinder 7 is hydraulically preloaded via the pump 16, which can be designed as a low-pressure pump. If an area of ​​1000^2 is assumed for the oil chamber 9 in the calculation example, it will be sufficient to raise the piston 8 back to its starting position even at pressures in the usual compressed air range. This also makes the contact of the two pistons extremely smooth and quiet.

[0018] After the impulse piston 2 is placed on the piston 8 of the impulse forming cylinder 7, oil is displaced from the oil chamber 9 of the impulse forming cylinder. The displacement is controlled by the hydraulic elements 10, 11, and 13 according to the requirements of the forming process. The outflow area 10 of the impulse forming cylinder, which is directly dependent on the path of the piston 8 of the impulse forming cylinder 7, changes due to the inherent movement of the piston 8 itself. In the simplest case, the inherent movement of the piston 8 increasingly closes an oil bore 10, which may, however, have a minimal opening towards the end. In this way, the influence of the piston speed, which would cause a large pressure difference immediately after the two pistons touch each other, is counteracted and, if necessary, reversed through optimal design.The aim is to introduce a force peak into the ram with the impulsion drive as quickly as possible at the end of the forming process, which is provided with a force peak.

[0019] This objective is also achieved with the aid of a pressure accumulator 13. Since its pressure always increases when filled with the oil displaced from the oil chamber 9, this also provides the opportunity to quickly introduce an adequate force peak into the ram with the pulse forming cylinder 7 at the end of the forming process, which is subject to a force peak. The use of pressure accumulators initially appears to be complex, but in this case it is not at all. In the simulation program, a travel of the piston 8 of the pulse forming cylinder 7 of 2 mm to 4 mm is sufficient to apply the final force of 10,000 kN. The ram is preloaded by the connecting rods with 3000 kN at the start of the forming process. With an area of ​​the oil chamber 9 of 1000 cm^2, this results in a displaced volume of only 0.2 to 0.4 liters.Since the shaped pulse only occurs in a time range of less than 2 to a maximum of 10 milliseconds, and a planned oil outflow occurs anyway to shape the desired pulse characteristic, pressure-loaded seals in the pulse-shaping cylinder 7 are unnecessary, and it can easily be loaded with extremely high pressures. With forces in the order of 6,000 kN for the pulse-shaping cylinder 7, pressures of 600 bar result for a surface area of ​​1000 cm^2, which can easily be provided without seals, especially since they do not need to be generated with a pump. The check valve 12 and the throttle 18 ensure continuous oil exchange to prevent overheating.Since the oil flows into the accumulator 13 in a few milliseconds, while the outflow via the throttle can take considerably longer, the function is ensured, especially since a small secondary oil flow via the throttle 18 is practically just another calculation element of the desired overall damping characteristic.

[0020] Fig. 2 shows the result of the computational simulation of cutting a large sheet with a known mechanical press, compared to Fig. 3a, with the use of the impulsive drive 27. In Fig. Figure 2 graphically illustrates the purely qualitative behavior of the ram travel [s] and ram speed [v]. The boundary condition of the simulation program is that the forming force increases to its maximum value within a ram travel of 1.4 mm, and then decreases to zero with the sheet break. This is illustrated by the example of cutting sheets with a thickness of 2 to 5 mm, depending on the location at which the sheet break occurs and the strength of the sheet. The low speed [v] of a crank drive in the lower working range corresponds to the slow increase in the pressing force together with the ram travel [s] according to the kinematic conditions. This does not involve the design of known presses, and only the qualitative differences to cutting according to Fig. 3a illustrates this.

[0021] It is evident that the force, which must directly follow the ram travel [s], increases over a crank angle of approximately 3.3 degrees to its maximum value, before abruptly breaking off. A separate representation of the force is omitted, as the expert will immediately see the sheet tear. At a stroke rate of 60 / min [for a very large press, e.g., 10,000 kN], this corresponds to a processing time of approximately 9 milliseconds. The spring stiffness of the press is set to the same everywhere in the simulation program. This time is determined using the impulsive drive, as shown in Fig. 3a, is drastically reduced, for example to one millisecond. Fig. The drastic oscillations shown in Figure 2 after the sheet metal tear of +-2mm cause the extremely unpleasant and well-known cutting impact.

[0022] Fig. Figure 3a, on the other hand, shows the result of the computational simulation of cutting a large sheet using a mechanical press equipped with the inventive impulse drive 27. The force again increases with the ram travel [s]. At a ram travel of 1.4 mm, the maximum force is reached, and the sheet tears off again. The known curve according to Fig. 2 drastic differences can be seen.

[0023] I; After the sheet metal break at a ram travel of 1 mm, the ram moves extremely smoothly. Only slight ram vibrations are detectable in the range of 10% when comparing the travel and speed curve without the inventive impulsive drive. It should also be considered that the speed is quadratically included in the energy calculation. How this result is achieved through the interaction of the impulsive forces with the connecting rod force is described in Fig. 4 explained.

[0024] II; The ram speed [v] increases during cutting to approximately 2.5 mm / msec or 2.5 m / sec. This is caused by the force pulse applied by the pulse cylinder 1 in conjunction with the pulse forming cylinder 7. The force pulse leads to a short-term

[0025] Maximum acceleration of the ram to speeds above which one can already speak of high-speed shear cutting.

[0026] Fig. Figure 3b again shows the result of the computational simulation of cutting a large sheet metal using a mechanical press equipped with the inventive impulse drive 27. A significantly larger ram mass was used here. As expected, due to the significantly larger passively accelerated mass, the total speed of the ram increases to only approximately 1.5 m / sec. The time required to complete the entire cut is significantly shorter than with the known kinematics on crank presses as in Fig. 2 nevertheless drastically reduced to approx. 1 / 2 ° crank angle and a time of 1 msec to 2 msec.

[0027] Compared to the boundary conditions of the calculation It. Fig. 2, the mass of the plunger was quadrupled.

[0028] Fig. Figure 4 explains the interaction of the individual forces involved in the overall process. The boundary conditions here correspond to the boundary conditions used in the kinematics calculation according to Fig. 3a. A pressure accumulator 13 is used here. This initially appears to require greater effort, but it is by no means. With an area of ​​the oil chamber 9 of 1000cm^2, this results in a displaced volume of only 0.2 to 0.4 liters over the calculated travel of the piston 8 of the pulse forming cylinder of 2 to 4mm. The forces emanating from the pulse forming cylinder 7 are additionally superimposed on the usual press forces, connecting rod force [F_pl] and forming force [F_u], whereby the total force resulting from the pressure in the oil chamber 9 of the pulse forming cylinder 7 is also individually assigned to the pressure increasing elements, damping throttle 10, 11 [F_dae] and pressure accumulator 13 [F_fed]. As can be seen from Fig. 1, the pressures from throttle 10, 11 and accumulator 13 have a summing effect here. The forces are shown in 10 kN. This means that the numerical values ​​of the forces in the diagram labels have the same value as the pressure in bar in oil chamber 9 with an area of ​​1000 cm^3. The cutting process is again set as the boundary condition, in which the forming force [F_u] must increase to a value of 10,000 kN until the sheet tears off after 1.4 mm. The calculation begins when a connecting rod force of 3,000 kN has already built up due to elastic expansion in the press; the punches of tool 26 are still sitting on the sheet. At a value of 3,000 kN, impulse piston 2 now touches piston 8 of impulse forming cylinder 7 at a specified speed, in this case 8.5 m / s. The mass of impulse piston 2 is 500 kg. Immediately a damping force [F_dae] with a magnitude of 2000kN sets in.This increases slightly even though the impulse piston 2 is already reducing its speed due to the counterforce from the piston 8 of the impulse shaping cylinder. This is due to a design-related decreasing overflow cross-section for generating the damping force [F_dae], whereby the overflow area is reduced due to the design as a result of the movement of the piston 8. In the simplest case, the oil bore 10 is increasingly closed by the piston 8. The force designated [F_fed] is created by the oil being diverted from the oil chamber 9 into the small pressure accumulator 13 and the associated increase in pressure in the pressure accumulator 13. The pressure accumulator 13 initially has a lower gas preload pressure, which means that the spring force [F_fed] caused by it is minimal.While the damping force [F_dae] decreases, the pressure in the pressure accumulator rises to 600 bar and causes the spring force [F_fed] to rise to 6000 kN with an area of ​​the oil chamber 9 of 1000 cm^3. The gas pressure in the pressure accumulator 13 can be adjusted via the pressure connection 15 for the respective tool in the press. A check valve 12 ensures that the pressure in the oil chamber 9 also approaches zero after the speed has dropped to zero. The damping force [F_dae] depends on the speed of the piston 8, while the spring force [F_fed] is path-dependent. This also allows for a wide variety of setting variants for shaping the force pulse emanating from the pulse-shaping cylinder 7. Optimum setting specifications can be developed quickly with the help of the simulation program.

[0029] Thus, the curve for the force [F_fed] is similar to the curve for the forming force [F_u] and thus advantageously causes the application of a force peak on the ram for the termination of a forming process characterized by a force peak and abrupt force drop. The curve for the force [F_fed] already approaches zero at a crank angle of 173.27 degrees, since the kinetic energy of the impulse piston 8 is used up by the correct dosage of its initial speed, while the forming force [F_u] only reaches zero at 173.35 degrees. This causes the kinetic energy of the ram to be consumed at the end of the forming process. This kinetic energy is due to the ram speed of approximately 1.4 m / sec shortly before the end of the forming process (see Fig. 3a) is still relatively high, but is absorbed by the residual forming process to minimize noise. This results in a low-vibration motion sequence and thus a very quiet operation of the machine during sheet metal cutting. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2012 019 386 A1

[0004] DE 102019001384A1 [0005, 0006] DE 000002623428

[0006] DE 000000209989A

[0006] DE 102016012803B4

[0006] DE 102011122492

[0006] DE 000002559150

[0006] DE 102019001384 [0015, 0016]

Claims

[1] Press with mechanical or hydraulic drive characterized by , which, in order to generate a required maximum force, in particular at force peaks such as during shear cutting or embossing, an impulse drive 27, preferably arranged in the ram but also in the head piece or table of the press, transmits a force impulse to the ram of the press before the required maximum force is reached. [2] Press according to claim 1 characterized bythat the press has already applied a proportional force with the built-in and known drives and then a pulse forming cylinder 7 shapes the force pulse applied by a pulse cylinder 1 to the ram in a force-superimposed manner in such a way that the ram just applies the required maximum force and at the same time the proportional force applied with the previously active conventional drives is not increased any further or is even significantly reduced or brought to zero in order to avoid relaxation shocks of the machine. [3] Press according to claim 1 and 2 characterized by that the speed of the ram during a cutting process with the pulse cylinder 1 and the pulse forming cylinder 7 is briefly increased to an increased amount in order to achieve a clean cut. [4] Press according to claim 2 and 3 characterized bythat the impulse of the impulse cylinder 1 is shaped by the impulse forming cylinder 7 in such a way that the effect of the impulse is already terminated before the end of the cutting process and the existing kinetic energy of the ram is converted into forming energy in order to achieve the required residual amount of the forming force and in this way the generation of noise is avoided. [5] Pulse forming cylinder 7 according to claim 2 characterized by that the outflow surface 10 from the oil chamber 9 of the pulse forming cylinder 7 is designed structurally dependent on the path of the piston 2 of the pulse forming cylinder 7, thus achieving speed-dependent pulse forming and that the oil from the oil chamber 9 is diverted into external pressure accumulators in order to realize a pressure increase in the oil chamber 9 dependent on the path of the piston 2 of the pulse forming cylinder 7. [6] Pulse forming cylinder 7 according to claim 2 characterized bythat the entire impulse drive can consist of several individual drives and can be mounted displaceably within the ram in order to set the impulse exactly above one or more centers of gravity of the forming force of the follow-on tool 26.

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