EP3377311B1 - Path-controlled press having a sliding block - Google Patents

Description

The invention relates to a path-bound press according to the preamble of claim 1.

DE-OS-1 627 435 describes a forging press in which an eccentric of a drive shaft engages in an opening of a sliding block. The sliding block is supported with an upper, convex side and a lower, convex side against a correspondingly concave surface of a sliding block. As the drive shaft rotates, the sliding block oscillates around a pendulum axis that runs through a lower area of the sliding block.

WO 2007/091935 A1 describes a drive for a press in which a first motor drives a flywheel that can be coupled to the press and in which a second motor is also provided to drive the press.

JP-S57 14499 A discloses a path-bound press according to the preamble of claim 1.

It is the object of the invention to provide a path-bound press in which a drive takes up little installation space.

This object is achieved by a path-bound press according to claim 1 and by a method for operating a path-bound press according to claim 15.

Such a design of the press drive allows a particularly low design of the drive, whereby, for example, relatively small flywheel diameters can be used. This allows an ideal combination with a power transmission using a sliding block, since such power transmissions can also be implemented with a low installation height.

The first motor essentially serves to drive the flywheel and at least partially replenish the energy extracted from the flywheel.

The second motor essentially serves to accelerate and/or decelerate the drive shaft decoupled from the flywheel in a state decoupled from the flywheel. In addition, the second motor can also be used to introduce additional drive energy when coupled. The deceleration energy that occurs during deceleration can be fed to the first motor via a converter in a possible detailed design. Motors in the sense of the present invention are understood to mean electric motors.

In the context of the invention, a sliding block is understood to mean an element that can be moved in a forced manner relative to a sliding block surface. The sliding block surface comprises in particular the pressure-side surface and the tension-side surface for guiding the sliding block.

In the context of the invention, a driver is understood to mean, for example, an eccentric or a crank pin. In the interest of a large power transmission, the driver is preferably an eccentric of the drive shaft, which runs, for example, with a circular circumference in an opening in the sliding block.

In the sense of the invention, a link is understood to be a movable component of the press that absorbs and transmits a working pressure from the link block during a press stroke or forming process. The link can in principle be designed as a common component with a ram of the press. In other embodiments, however, another gear of any design, for example a wedge deflection, can be provided between the link and the ram. In the area where the force is absorbed in the pressure direction, the link preferably has a pressure piece that has material properties optimized for contact with the link block.

A press in the sense of the invention generally relates to a press for forging, punching, deep drawing or any other forming process for which path-bound presses are used.

According to the invention, the clutch is closed in normal operation when a drive-side and an output-side speed on the clutch are at least approximately the same, with the speeds being adjusted via a targeted control of the second motor. This allows a significant reduction in wear on the clutch.

In the interest of a simple and space-saving design, the first motor and the flywheel are arranged coaxially to one another. They are preferably integrated as a structural unit to form a flywheel motor. Such a flywheel motor advantageously dispenses with a space-consuming belt drive and additional motor console. In another possible embodiment, the motor and the flywheel are arranged coaxially and connected to one another via a gear, preferably a planetary gear, so that transmission ratios can also be implemented depending on requirements. This can enable particularly small flywheel masses.

It is generally advantageous for the flywheel to be coupled to the drive shaft without a gear ratio, with the flywheel being arranged in particular concentrically to the drive shaft. Such a simple design without a reduction gear can be integrated particularly advantageously if the flywheel can be designed with a sufficiently small diameter. This is again made possible by the drive concept according to the invention.

To avoid complex gears and in the interest of a compact design, in a preferred embodiment the second motor is designed as a torque motor arranged concentrically to the drive shaft. A torque motor is generally understood to mean a A torque motor is a high-torque, high-pole motor that usually runs on a hollow shaft. Torque motors also have a high torque even when stationary.

It is particularly advantageous if a brake on the drive shaft is provided concentrically to the torque motor and overlaps the torque motor in the axial direction. The brake can be placed in particular in the area of a hollow shaft of the torque motor in order to also use this installation space. The brake can be a mechanical brake for generating frictional heat or an electrical recuperation brake.

The brake can be a holding brake to ensure that the press comes to a standstill when it is not in use. It can particularly preferably be a spring-loaded brake that can be opened pneumatically and closed hydraulically and/or electromagnetically.

It is generally advantageous that the drive shaft runs through an angle of rotation of more than 360°, starting from a stationary start position via the pressing stroke to a stationary stop position. Preferably, this is an angle of rotation between 370° and 450°. This allows a larger acceleration path before the actual pressing process or a larger braking path after the actual pressing process, so that the corresponding motors and brakes can be dimensioned smaller accordingly. This applies in particular to the second motor.

Overall, a high power output is possible with the drive described above. This means that a large drop in speed can be recharged within a given charging time. A high permissible drop in speed allows a small flywheel, which is an advantage.

In order to avoid contamination of a working area with lubricating grease, it can advantageously be provided that a main bearing point of the drive shaft is lubricated by means of a circulating oil lubrication system.

In a generally preferred embodiment of the invention, it is provided that the pressure-side sliding surface on the sliding block and/or the tension-side sliding surface of the sliding block is designed to be straight. The straight shape of a pressure-side sliding surface or both pressure-side sliding surfaces enables simple manufacture of the sliding block.

In a generally preferred embodiment of the invention, it is provided that the pressure-side sliding surface on the sliding block has a concave or convex curvature, with the tension-side sliding surface of the sliding block having a different, concave or convex, curvature. The concave or convex shape of the pressure-side sliding surface makes it easy to achieve a force transmission through the sliding block that corresponds to a slider-crank mechanism. At the same time, a large contact surface is achieved in the area of the sliding surface, so that a design for large pressing forces can be easily achieved. Overall, this results in an optimized force-displacement curve.

In particular, the pressure-side, concave curvature and the tension-side, convex curvature can each be designed in the shape of a circular arc. The curvatures are preferably arranged concentrically around the same point through which a pendulum axis of the sliding block also runs. Both sliding surfaces form positively guiding sliding block surfaces of a sliding block gear for the sliding block.

In a first variant of the invention, the sliding block has a concave sliding surface on the pressure side and a convex sliding surface on the tension side. This corresponds to the kinematics of a slider-crank mechanism, in which the dead center of a working stroke or pressing process is in an extended position of the slider-crank mechanism.

In a second variant of the invention, the sliding block has a convex sliding surface on the pressure side and a concave sliding surface on the tension side. This corresponds to the kinematics of a slider-crank mechanism, in which the dead center of a working stroke or pressing process is in a cover position of the slider-crank mechanism.

The design of a path-bound press according to the invention generally allows for a low overall height. This leads to shorter spring lengths for the column, ram and/or link of the press. This improves the rigidity compared to conventional eccentric presses of the same column design.

Furthermore, the design according to the invention makes it possible to have a particularly long rigid unit consisting of the link and ram for a given height of the press. This allows particularly good lateral guidance of the ram or the rigid unit, even with high pressing forces.

It is generally advantageous that the sliding block executes a pendulum movement about a pendulum axis, with the pendulum axis being arranged outside the sliding block. In general, the pendulum axis is preferably arranged in a fixed position relative to the sliding block. Assuming a linear forced guidance of the sliding block, the sliding block then causes a movement transmission in the manner of a slider-crank mechanism with respect to the pendulum axis or with respect to the sliding block. In the sense of the invention, a different forced guidance of the sliding block is also conceivable depending on the requirements, so that the kinematics of a slider-crank mechanism is only one of various possible movement transmissions. The invention is not limited to the specifically described variants of slider-crank mechanisms.

In a preferred development, it is provided that the driver runs around an eccentric axis in the sliding block, wherein the eccentric axis has a distance R from the shaft axis, wherein the eccentric axis has a Distance L from the pendulum axis, and where: L:R >= 4. Particularly preferred is also: 12 >= L:R >= 5. With linear guidance of the link, the sizes R and L therefore mean the characteristic sizes of the push rods of an analogue slider-crank mechanism, and the quotient R:L corresponds to the push rod ratio Lambda (or L:R = 1/Lambda) in an analogue slider-crank mechanism. Such a design of the gear of the press according to the invention allows a high ratio between a pressing force acting in the guide direction of the pressure piece and a normal force acting perpendicular to it. A certain normal force is desired in order to ensure that the link and/or the ram are well positioned on a lateral guide. By combining this with the use of a sliding block, a large inverse push rod ratio 1/Lambda is possible without the overall height of the press having to be increased. Due to the above-mentioned features, similar pressure contact times (parameter: lambda) as with conventional eccentric presses with pressure rods can be achieved, even with a low installation height and correspondingly good rigidity.

In the first variant, analogous to the extended position of a slider crank mechanism, the pendulum axis is on the side of the compression direction with respect to the shaft axis. The compression contact time is the same as with conventional presses with a pressure rod for the same rotation time. In the second variant, analogous to the cover position of a slider crank mechanism, the pendulum axis is on the side of the tension direction with respect to the shaft axis. The compression contact time is higher for the same rotation time than with conventional presses with a pressure rod, but this can be an advantage with special forming processes or materials.

In a generally preferred development of the invention, an adjusting element, preferably in the form of an adjustable, rotatable eccentric ring, is arranged between the driver and the sliding block. Such an adjusting element can be used, for example, to adjust the height of a tappet.

In a preferred embodiment of the invention, the link is moved substantially in line with a ram of the press during the press stroke. This corresponds to a linear and direct transmission of the press force.

In an alternative embodiment of a press according to the invention, a force deflection takes place between the link and a ram of the press. The force deflection can preferably take place by means of a wedge. This allows the general advantages of a wedge press to be combined with the advantages of a press according to the invention.

In a generally advantageous development of the invention, an ejection mechanism is provided which is fixed in position relative to the guide rail and has an ejector which can be moved relative to the guide rail and acts on a workpiece, the ejection mechanism being actuated by the movement of the guide rail. This allows a workpiece to be ejected easily and effectively after a pressing process. Such an ejection mechanism is particularly preferably combined with a guide rail of the second embodiment, which has a convex sliding surface on the pressure side. With otherwise identical dimensions, this means that the guide rail has a greater path in the area of the sliding surface on the pressure side, which allows a particularly easy and effective transfer of movement to the ejector. The ejector can be actuated, for example, by a ramp, cam or similar structure formed on the guide rail, which actuates the ejector against a restoring spring force when the drive shaft reaches a corresponding position.

In a preferred detailed design, a gear can be arranged between the sliding block and the ejector so that the force and movement of the ejector are further optimized. The gear can be a linkage gear, a bell crank or similar.

Further advantages and features emerge from the embodiments described below and from the dependent claims.

Fig. 1

zeigt eine schematische Schnittansicht eines ersten Ausführungsbeispiels einer erfindungsgemäßen weggebundenen Presse, wobei die Schnittebene parallel zu einer Antriebswelle verläuft.

Fig. 2

zeigt die Presse aus Fig. 1 in einer Schnittansicht mit senkrecht zu der Antriebswelle verlaufender Schnittebene entlang der Linie I-I.

Fig. 3

zeigt eine Schnittansicht entlang der Linie II-II der Presse aus Fig. 1 mit einem Verstellglied.

Fig. 4

zeigt eine Skizze eines Kulissensteinantriebs als Detail der Presse aus Fig. 1.

Fig. 5

zeigt eine Skizze eines zweiten Ausführungsbeispiels der Erfindung mit einem Kulissensteinantrieb und einem dazu kombinierten Keilantrieb.

Fig. 6

zeigt eine Skizze eines dritten Ausführungsbeispiels der Erfindung, wobei eine andere Variante des Kulissensteins mit druckseitig konvexer Gleitfläche vorliegt.

Fig. 7

zeigt eine Skizze eines vierten Ausführungsbeispiels, bei dem eine Ausstoßmechanik mit einem Kulissensteinantrieb gekoppelt ist.

Fig. 8

zeigt eine Skizze eines fünften Ausführungsbeispiels, bei dem eine Ausstoßmechanik ein Getriebe umfasst.

Preferred embodiments of the invention are described below and explained in more detail with reference to the accompanying drawings.

Fig.1

shows a schematic sectional view of a first embodiment of a path-bound press according to the invention, wherein the sectional plane runs parallel to a drive shaft.

Fig.2

shows the press Fig.1 in a sectional view with the cutting plane perpendicular to the drive shaft along the line II.

Fig.3

shows a sectional view along the line II-II of the press from Fig.1 with an adjusting element.

Fig.4

shows a sketch of a sliding block drive as a detail of the press from Fig.1 .

Fig.5

shows a sketch of a second embodiment of the invention with a sliding block drive and a combined wedge drive.

Fig.6

shows a sketch of a third embodiment of the invention, wherein another variant of the sliding block with a convex sliding surface on the pressure side is present.

Fig.7

shows a sketch of a fourth embodiment in which an ejection mechanism is coupled to a sliding block drive.

Fig.8

shows a sketch of a fifth embodiment in which an ejection mechanism comprises a gear.

The path-bound press according to the invention according to the embodiment according to Fig.1 comprises a drive shaft 1 with a shaft axis W, which is divided into two Main bearings 2 are rotatably mounted relative to a press frame 3. The main bearings 2 preferably have circulating oil lubrication.

Between the main bearings 2, the drive shaft 1 has an eccentric driver in the form of an eccentric 4. The eccentric 4, which is circular in cross-section, has an eccentric axis E which is offset by a radial distance R from the shaft axis W.

The eccentric 4 passes through a sliding block 5 in a bore 6 corresponding to the diameter of the eccentric. For assembly purposes, the sliding block is made up of several parts.

The sliding block 5 is in turn guided in a guide 7. The guide 7 is designed as a housing that can be moved relative to the press frame 3. The guide 7 comprises a pressure piece 8 on a pressure side, on which a pressure-side sliding surface 8a is formed. On a side opposite the sliding block, a tension-side sliding surface 7a is formed on the guide.

The sliding block 5 has a pressure-side sliding surface 5a, which rests on the sliding surface 8a of the pressure piece 8, and a tension-side sliding surface 5b, which rests on the tension-side sliding surface 7a of the sliding block 7.

The pressure-side sliding surface 5a is concavely formed on the sliding block 5. The tension-side sliding surface 5b is convexly formed on the sliding block 5. The sliding surfaces 5a, 5b, 7a, 8a are each formed as sections of a cylinder surface, with the cylinder axes running parallel to the shaft axis W. The sliding surfaces 5a, 5b, 7a, 8a run concentrically around a pendulum axis P of the sliding block 5 that is parallel to the shaft axis W. In other words, the cylinder axes of the cylinder surfaces to which the Sliding surfaces 5a, 5b, 7a, 8a each form cutouts, together with the pendulum axis P.

In the first variant of the sliding block described here, the pendulum axis P is therefore located on the pressure side and outside the sliding block, since the pressure-side sliding surface 5a of the sliding block 5 is concavely shaped. When the drive shaft 1 rotates, the sliding block 5 undergoes a forced pendulum movement around the pendulum axis P.

The pendulum axis P is fixed in space with respect to the guide 7 or the pressure piece 8. The guide 7 and the pressure piece 8 provided on it are accommodated by lateral guides 9 in which they can each be moved linearly in a direction perpendicular to the shaft axis W. By a downward movement with respect to the illustration in Fig.2 a pressing stroke is carried out in which the driving force of the drive shaft 1 acts on the pressure piece 8 via the sliding block 5. After a bottom dead center of the movement, the driving force of the drive shaft 1 acts on the tension-side sliding surface 7a of the sliding block 7 via the sliding block 5, so that the sliding block 7 and the pressure piece 8 are brought back in the opposite direction to the pressing stroke.

In the present case, clamping devices 7b are arranged on the underside of the guide 7, with which a press ram and/or a tool holder and/or a tool can be attached. These perform identical movements to the guide 7 or the pressure piece 8.

Through the guides 9, the guide 7 or the pressure piece 8 (or a ram or tool of the press) perform a movement similar to that of a slider crank drive. An example of a slider crank drive is the transmission of motion between the piston and the crankshaft in a conventional combustion engine.

The quantities that characterize the movement are the radial distance R on the one hand and a distance L between the pendulum axis P and the eccentric axis E. In the case of the conventional slider crank drive, the ratio R:L corresponds to the push rod ratio lambda. With a constant angular velocity of the drive shaft 1, the greatest ram speed occurs when R and L are at right angles to each other.

In the present example, the dead center of the working stroke corresponds to the extended position of an analog slider crank mechanism. This means that the distances R and L are collinear and one behind the other at the lowest point of the tool. The dead center of the working stroke is also referred to as the bottom dead center.

In contrast to a pure sinusoidal drive (e.g. a sliding block sliding horizontally in the guide rail with a flat sliding surface on the pressure side), the maximum tappet speed only occurs after 90° after TDC (top dead center).

In the present case, the reciprocal value 1/Lambda = L:R is used to optimize the drive of the press according to the invention. It has been found that a forging press is particularly advantageously designed in a range L:R = 8 with regard to the requirements of the movement sequence and the pressure forces occurring on the lateral guides 9. In general, the ratio 4 <= L:R should preferably be. Particularly preferred is 5<= L:R <= 12.

Such relatively large inverse push rod ratios have practically no effect on the overall height of a press in question, since the position of the pendulum axis P is only defined by the movement of the sliding block and no physical shaft or bearing is required at this position.

The above-described recording and movement of the sliding block is Fig.4 explained further. Force vectors Fs, Fp and Fn are also shown, which have the following meaning:
Fs is the total compressive force exerted by the sliding block 5. Fs lies on a straight line that runs perpendicularly through the eccentric axis E and the pendulum axis P.

Fp is the force component of Fs that acts in the direction of the press stroke or on the workpiece. In the specific design of the press according to Fig.1 This is the vertical force component.

Fn is the force component of Fs that is perpendicular to Fp and also perpendicular to the guides 9 or the direction of the press stroke. The behavior of the moving parts in the guides 9 is largely determined by Fn.

A respective angle WF between Fp and Fs is an expression of the crank angle and the ratio L:R. Due to the selected ratio L:R, the angle WF in the present example of a press is relatively small.

A drive of a press according to the invention is described below.

A drive of the drive shaft 1 comprises a first motor 10, a flywheel 11 that can be driven by the first motor 10, and a second motor 12. The flywheel 11 can be detachably coupled to the drive shaft 1 via a clutch 13. The second motor 12 drives the drive shaft 1 directly. In one possible operating mode, deceleration or braking with this drive is not carried out via a brake, but via the second motor 12.

In the present case, the flywheel 11 and the first motor 10 are combined to form a structural unit in the form of a flywheel motor 14. The first motor 10 and the flywheel 11 are arranged coaxially to one another and to the shaft axis W of the drive shaft 1. The motor 10 and the flywheel 11 are directly connected to one another. A transmission, for example by means of a gear or a belt drive, does not take place here. In other embodiments not shown, a transmission can be provided between the flywheel and the first motor, for example by means of a planetary gear.

The clutch 13 is arranged directly on the flywheel motor 14 and is also in a concentric or coaxial position on the shaft axis W. Flywheel motor 14 and clutch 13 are arranged on the same of two ends of the drive shaft 1.

The second motor 12 is arranged at the second end of the drive shaft 1, opposite the main bearing 2. The second motor 12 is also positioned coaxially to the shaft axis W above the drive shaft 1. It drives the drive shaft directly and without gearing. For this purpose, the second motor 12 is designed as a torque motor. The second motor 12 therefore has a high torque even when stationary.

A brake 15 of the drive is positioned concentrically and overlapping the second motor 12 in the axial direction. In particular, the brake is positioned predominantly in a hollow shaft of the second motor 12, whereby this installation space is used optimally. By means of the brake 15 supported against the press frame, the drive shaft 1 can be braked with high power and/or brought to a standstill if necessary. The brake can be designed as an electrical recuperation brake and/or as a mechanical brake that generates frictional heat. In the present case, the brake 15 is preferably spring-loaded and serves as a safety element in possible operating mode when the press is at a standstill. It can be opened pneumatically or closed hydraulically and/or electromagnetically.

In particular, the view Fig.2 makes it clear that the flywheel 11 has a sufficiently small diameter so as not to overlap in height with a working area 16 of the press. This allows optimal access to the working area 16

The drive described above now works as follows:
In general, the flywheel 11 is permanently held at a desired speed by the first motor 10. The second motor 12 serves to accelerate the drive shaft 1 from a resting starting position to a speed that is the same or at least almost the same as the flywheel before a pressing process, while the clutch 13 is still disengaged. If the speed difference is sufficiently small, the clutch 13 is then engaged or closed so that little or no friction loss occurs at the clutch. Accordingly, the clutch is relatively small.

The subsequent pressing stroke and forming process of a workpiece brakes the drive shaft 1 and energy is extracted from the flywheel 11. At the same time, the first motor 10 and the second motor 12 work together at high power in order to at least partially compensate for the energy extraction. As a result, the flywheel is relatively small.

After the pressing stroke or forming process, the drive shaft 1 is decoupled again from the flywheel 11. With the aid of the brake 15, and if necessary also by reversing the second motor 12, the drive shaft 1 is then brought to a standstill.

Particularly preferably, an electronic control of the press is designed in such a way that the drive shaft 1, starting from the stationary start position, passes through a rotation angle of more than 360° through the press stroke/forming process to the stationary stop position. The rotation angle is preferably between 370° and 450°.

In the present example, the angle of rotation is approximately 390°. To do this, the drive shaft is first rotated back by approximately 30° against the working direction, i.e. 30° before top dead center, before acceleration in the working direction by the second motor 12. This does not cause a collision or impairment of the working area 16, but significantly increases the available acceleration angle for the subsequent rotation of the drive shaft in the working direction. This means that the second motor 12 can be designed to be relatively small.

Fig.3 shows the press Fig.1 in a sectional view with section plane II-II running perpendicular to the drive shaft. An additional adjusting element 17 is provided, by means of which the height of the sliding block 5 can be adjusted. This adjustment can also be made during operation. In one possible operating mode, the adjustment can be made in stages between two successive strokes.

The adjusting member 17 comprises an eccentric ring 18 which is arranged between the bore 6 in the sliding block 5 and the eccentric 4 of the drive shaft 1. The eccentric ring 18 can be rotated in its seat via an actuator 19 so that the bore receiving the eccentric 4 changes its position with respect to the sliding block 5.

Fig.2 shows a clamp 17a of the adjusting element 17. The clamp 17a can be opened hydraulically. The closing of the clamp 17a can be hydraulically or mechanical (self-locking) or combined hydraulic and mechanical.

Fig.5 shows a second embodiment of a press according to the invention. In this case, a ram and/or tool of the press is not moved directly and linearly by the link 7. Instead, a force deflection is provided between the pressure piece and a ram of the press. In the present case, the force deflection takes place by means of a wedge 20, which is displaceable relative to a frame-fixed support surface 21 inclined to the direction of the press stroke. In the present case, the wedge 20 is firmly connected to the link 7. A ram 22 of the press rests displaceably on a side of the wedge 20 opposite the support surface 21.

If one wants to make an analogy to a simple slider crank drive, it must be taken into account that the pendulum axis P is displaced parallel to the support surface 21 during the transmission of motion. Accordingly, the press stroke HP is considered to run in the direction of this offset in the sense of the invention.

Accordingly, a movement HS of the ram 22 of the press is redirected by approximately 120° to the press stroke HP of the link 7. Such a wedge drive can achieve a particularly uniform force distribution across the width of the ram.

With regard to the design of the drive of the press and the design and movement transmission of the sliding block, the second embodiment does not show any changes to the example according to Fig.1 on.

In the Fig.6 In the embodiment of the invention shown, the sliding block is formed according to a second variant. The pressure-side Sliding surface 5a on the sliding block 5 is convexly shaped, in contrast to the concave shape in the previously described examples.

The tension-side sliding surface 5b on the sliding block 5 is also shaped in the opposite way to the previous examples, i.e. concave. The corresponding sliding surfaces 7a, 8a on the sliding block are also curved in the opposite way. The sliding surfaces 5a, 5b, 7a, 8a are as in the first variant according to Fig.4 each formed as cutouts of a cylinder surface, with the cylinder axes running parallel to the shaft axis W. The sliding surfaces 5a, 5b, 7a, 8a in turn run concentrically around a pendulum axis P of the sliding block 5 that is parallel to the shaft axis W.

The pendulum axis P is therefore also located outside the sliding block 5. Unlike in the first variant, the pendulum axis P in the second variant is on the tension side with respect to the sliding block 5. For the sliding block 5, rotation of the drive shaft 1 again results in a forced pendulum movement around the pendulum axis P.

The second variant also corresponds to an analog slider-crank mechanism with the characteristic dimensions L (distance between the pendulum axis P and the shaft axis W) and R (distance between the eccentric axis E and the shaft axis W). Unlike the first variant, however, the dead center of the working stroke corresponds to a cover position of an analog slider-crank mechanism. This means that the distances R and L are collinear and lie one above the other at the lowest point of the tool.

It is understood that other kinematics such as eccentric slider crank mechanisms can also be realized with a sliding block design according to the invention.

In the Fig.7 In the embodiment shown, an ejection mechanism 23 is integrated into the press, which is actuated by means of the movement of the sliding block.

The ejection mechanism comprises an ejector 24, which runs linearly displaceably in a guide of the ram 22 and can press against a workpiece (not shown) at the lower end of the ram.

After a pressing process, the ejector 24 is moved against the workpiece by means of a mechanical positive guide and pushes it out of a tool (not shown). In this way, a reliable workpiece change is made possible in a simple manner.

The ejector 24 is actuated by means of a ramp 27 on the sliding block 5. The ramp 27 rests against a head 28 of the ejector 24, which is in the form of a ball. The sliding block performs its pendulum movement around the pendulum axis P, sliding along the pressure-side sliding surfaces 5a, 8a. The ejector 24 is initially in a position reset by means of a spring 29, in which it does not press on the workpiece.

After the working stroke or pressing process has been completed, the ramp 27 begins to press in the ejector 24 via the ball 28. In Fig.7 Approximately the starting point of this ejection process is shown, with the sliding block 5 in the central position and the tappet 22 in a bottom dead center.

Subsequently, the sliding block 5 moves in the illustration according to Fig.7 further to the left and the ramp 27 moves the ejector 24 relative to the plunger 22 or to the guide 7 against the workpiece. The ejector 24 performs a movement by a stroke HA against the force of the spring 29.

In the present case, the ejector mechanism is illustrated using the first variant of the sliding block 5 with a concave sliding surface 5a on the pressure side. The ejector mechanism can also preferably be combined with the second variant of the sliding block 5 with a convex sliding surface 5a on the pressure side. This has the advantage that the linear path of the sliding block 5 along the sliding surface 5a is larger with otherwise identical dimensions of the press, which allows a less steep design of the ramp 27.

By interposing a hydraulic piston 25 with a piston rod 26, the stroke HA of the mechanical ejector 23, 24 can be increased. This means that the large force required for ejection is applied by the mechanical ejector with a small stroke HA. The hydraulic piston increases the stroke HA by the stroke HH. The hydraulic piston 25 is operated via a valve with hydraulic control 34.

In the example in Fig.8 a further development of the ejector mechanism 23 is shown, in which a gear 30 is arranged between the sliding block 5 and the ejector 24.

In the present case, the gear 30 is designed as a reversing lever, which is mounted in a rotary bearing or pivot bearing 31 on the sliding block 7. The sliding block 5 is connected to the reversing lever in a rotary bearing 32, with the pivot point of the rotary bearing 32 being aligned with the sliding surface 5a. The rotary bearing 32 can be designed as a cam roller. The pivoting movement of the reversing lever is then positively controlled via the cam roller 32 by the cassette guide 33 arranged on the sliding block 5.

Opposite the pivot bearing 32, a ramp 27 is formed on the reversing lever 30, which, as in the previous example, engages the ejector 24. The reversing lever in particular enables a longer ramp in order to better control the ejector 24.

It is understood that the specific features of the preceding embodiments can be combined with one another as required, as long as they fall within the scope of the appended claims.

List of reference symbols

1

drive shaft

2

Main bearing

3

Press frame

4

Eccentric (driver)

5

Scenic stone

5a

pressure-side, concave sliding surface on the sliding block

5b

Tension-side, convex sliding surface on the sliding block

6

Drilling in the sliding block

7

Scenery

7a

Tension-side sliding surface on the link

7b

Clamping device

8th

Pressure piece of the backdrop 7

8a

pressure-side sliding surface on the pressure piece

9

side guides

10

first engine

11

flywheel

12

second engine

13

coupling

14

Flywheel motor, structural unit of flywheel 11 and motor 10

15

brake

16

Workspace

17

Adjusting element

17a

Clamping the adjusting element

18

Eccentric ring

19

Actuator

20

wedge

21

Support surface

22

Pestle

23

Ejection mechanism

24

Ejector

25

Hydraulic piston of the ejector

26

Ejector piston rod

27

Ramp for controlling ejector

28

Head of the ejector

29

ejector return spring

30

Gearbox, reversing lever

31

Pivot bearing reversing lever - link (pivot bearing)

32

Pivot bearing reversing lever - sliding block (cam roller)

33

Cassette guide

34

Valve with hydraulic control

W

Drive shaft axis

E

Axis of the eccentric

P

Swing axle of the sliding block

R

radial distance between W and E

L

radial distance between E and P

Fs

total pressure force

Fp

Force share in the direction of the press stroke

Fn

Force component perpendicular to the press stroke

WF

Angle between Fs and Fp

HP

Press stroke

HS

Ram movement

HA

Ejector stroke (mechanical)

HH

Hydraulic lift

S

Pivoting movement of the reversing lever

Claims (15)

1. Path-controlled press, comprising:

   at least one drive shaft (1) with an entrainer (4) eccentric relative to a shaft axis (W), and

   a slide block (5), wherein the slide block (5) is driven by the entrainer (4) to execute a constrained motion,

   wherein the slide block (5) during execution of a press stroke is guided at at least one thrust-side slide surface (5a) relative to a thrust-side surface of a guide (7),

   wherein the slide block (5) has a draw-side slide surface (5b) which is opposite the thrust-side slide surface (5a) and which is guided at a draw-side surface of the guide, wherein

   a drive of the drive shaft comprises a first motor (10) and a flywheel (11), which is drivable by the first motor, wherein the flywheel (11) can be detachably coupled to the drive shaft (1) by means of a clutch (13),

   characterised in that

   the drive comprises a second motor (12), wherein the drive shaft (1) is drivable by way of the second motor (12),

   wherein the first motor (10) and the flywheel (11) are arranged coaxially with respect to one another, wherein they are integrated in particular as a constructional unit to form a flywheel motor (14).
2. Path-controlled press according to claim 1, characterised in that the flywheel (11) can be coupled without translation to the drive shaft (1), wherein the flywheel (11) is arranged in particular concentrically with the drive shaft (1).
3. Path-controlled press according to one of claims 1 and 2, characterised in that the second motor (12) is constructed as a torque motor arranged concentrically with the drive shaft (1).
4. Path-controlled press according to claim 3, characterised in that a brake (15) of the drive shaft (1) is provided concentrically with the torque motor (12) and congruently in axial direction with the torque motor (12).
5. Path-controlled press according to any one of claims 1 to 4, characterised in that the drive shaft (1) is configured to run, starting from a resting start position, by way of the press stroke to a resting stop position through an angle of rotation of more than 360°, in particular between 370° and 450°.
6. Path-controlled press according to any one of the preceding claims, characterised in that the thrust-side slide surface (5a) at the slide block (5) and/or the draw-side slide surface (5b) of the slide block (5) is or are configured to be straight.
7. Path-controlled press according to any one of claims 1 to 5, characterised in that the thrust-side slide surface (5a) at the slide block (5) has a concave or convex curvature, wherein the draw-side slide surface (5b) of the slide block (5) has a respectively different concave or convex curvature.
8. Path-controlled press according to claim 7, characterised in that the slide block (5) executes a pendulating motion about an axis (P) of pendulation, wherein the axis (P) of pendulation is arranged outside the slide block (5).
9. Path-controlled press according to claim 8, characterised in that the entrainer (4) travels about an eccentric axis (E) in the slide block (5), wherein the eccentric axis (E) has a spacing R relative to the shaft axis (W), wherein the eccentric axis (E) has a spacing L from the axis (P) of pendulation, and wherein L:R > = 4, in particular 12 > = L:R > = 5.
10. Path-controlled press according to any one of claims 6 to 8, characterised in that an adjusting element (17), in particular in the form of a settable, rotatable eccentric ring (18), is arranged between the entrainer (4) and the slide block (5).
11. Path-controlled press according to any one of the preceding claims, characterised in that the pressure member (8) is moved during the press stroke substantially in line with a ram of the press.
12. Path-controlled press according to any one of claims 6 to 8, characterised in that a force deflection particularly by means of a wedge (20), is effected between the pressure member (8) and a ram (2) of the press.
13. Path-controlled press according to any one of claims 6 to 11, characterised in that an ejecting mechanism (23) mounted to be stationary relative to the guide (7) is provided with an ejector (24) movable relative to the guide (7) and acting on a workpiece, wherein the ejector mechanism (23) is actuated by the movement of the slide block (5).
14. Path-controlled press according to claim 12, characterised in that a transmission (30) is arranged between the slide block (5) and the ejector (24).
15. Method of operating a path-controlled press according to any one of the preceding claims, characterised in that the clutch (13) in normal operation is engaged when a drive input and a drive output rotational speed at the clutch (13) are at least approximately equal, wherein equalisation of the rotational speeds takes place by way of selective control of the second motor (12).

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