EP2186631A1 - Shaping machine with efficient operation - Google Patents

Abstract

The part has a direct current- or alternating current motor (12) connected to a shaft of a flywheel mass (16) of a forming machine over a force transmission mechanism. The mass is durably detached from its force flow or demounted from the machine. A coupling area (8) for the mechanism is made relative to an original condition in a main power train of the machine. The mechanism is coupled with servo motors (40). A press device with the drive, a clutch (20) and a brake (22) is provided in the power train and the mass. Independent claims are also included for the following: (1) a method for retrofitting a head part of a forming machine (2) a method for improved operation of a forming machine.

Description

STATE OF THE ART

The present invention relates to forming machines, especially forming presses, as well as a method for improved operation and methods for converting an existing forming machine.

The aforementioned forming machines are known in the prior art in numerous technical variations. In the field of press machines, there are so-called work-related hammers, flywheel spindle presses, or power-driven machines such as hydraulic presses, flywheel-free spindle presses, or off-press machines such as crank presses, eccentric presses, toggle presses, or steering lever presses. Furthermore, in the prior art under forming machines also rolling and bending machines, as well as cutting and punching machines are known, which all also cause a forming process of a workpiece in that at least one tool is moved in the direction of another tool and the intermediate workpiece in contact accordingly is transformed. By "forming" is meant in a broad sense herein cutting and punching, as well as rolling and bending.

A common characteristic of all these machines is especially if they are designed for industrial use for the deformation of relatively large sheet metal parts and for a long service life, that their base frame is very solid, which is particularly true for all presses to torsion sometimes very large pressures to be able to accurately reshape the workpieces.

In addition to the base frame for such press machines, all other components that are essential for the static and dynamic force loads in the power flow of a press machine or those that are indirectly involved in power transmission are also designed very solid.

Using the example of an electric motor operated eccentric with flywheel this applies in particular for the plunger, one or more, the ram moving connecting rod, the eccentric eccentric bushing, the flywheel including the shaft and their force-transmitting compounds beispielsweie in the form of gears in the head part of the press on the one hand to the eccentric shaft and on the other hand to the electric motor as a drive, and for the intervening in the drive train parts such as countershaft transmission, clutches, brakes and possibly blocking devices that can hold the plunger in an emergency exhibition. All these components are mechanically very solid, expensive to manufacture and partly specialized for the application of a particular press machine made.

According to FIG. 1 is shown in section the upper part of an eccentric-based forming press, as known from the prior art. The illustration thus essentially shows the head part of the press. The frame 10 of the press is shown only in sections. It can be a C-frame or a gate or any other frame.

A classic AC or DC electric motor 12 drives via a belt drive 14 to a flywheel 16, which sits on a flywheel 18. On this shaft 18 is followed by a clutch 20, a brake 22, which - as known in the art - on demand and can be turned off. At the end of the flywheel mass shaft 18 sits a gear 24, which reduces the speed of the flywheel shaft 18 to a lower speed. The rotation is thus transmitted from the flywheel shaft 18 on the eccentric shaft 26 which is coupled to the large gear of the transmission.

The eccentric shaft 26 opens into an eccentric bushing. The eccentric sleeve is enclosed by the head of a connecting rod 30, which converts the rotational movement of the eccentric shaft 26 together with the eccentric bushing 28 in an up and down movement. At the lower end of the connecting rod is attached to the connecting rod of the so-called plunger 32 with the coupling to any tool, which in turn is then adapted to act on a workpiece, which applies it to transform by a corresponding movement downward. This is completely known in the art.

The actual pressing process is usually carried out by the following steps according to the prior art:

By means of an electric motor, a flywheel is driven via a belt drive, from which the movement is transmitted to the clutch bell via a small gear and a large gear (mounted on the eccentric shaft). During the intended driving movement, the inner clutch bell presses against the clutch plate fitted with friction pads (wedged on the eccentric shaft), which then frictionally receives the movement of the gear wheel. At the same time, the mechanically closed brake is pressed by means of a piston ring against the springs, and thus opened.

The con rods mounted on the eccentric press with the help of half-shells on the plunger. Balancing cylinders that sit on the press help the drive to balance the ram and the upper part of the tool. The function of the clutch-brake combination is realized in that both are controlled with separate press safety valves, which are characterized by undercut or overlap against each other.

As one skilled in the art of forming machines knows, these machines must meet high safety requirements if they are to be used industrially. For example, various important functions must be designed redundantly, for example a brake for the movement of the plunger.

This has the direct consequence that a press operator faces tremendous costs for new investments if he also wants to profit from the attractive technological advances in press technology.

As an example may be mentioned the change from a driven with an electric motor eccentric press for forming sheet metal parts for the production of car hoods. In such a forming press, the energy for the forming-pressing operations in each case comes from the movement of a flywheel, wherein the movement of the flywheel is then switched on and off specifically for each pressing process. If the operator of this press wants to use the more modern and universally applicable technology of servo presses, he has no choice but to invest in a complete new system.

It should be noted that the servo-forming presses have improved functionality and flexibility for the respective forming applications and in particular are more versatile that the movement of the plunger is arbitrarily programmable, thereby arbitrary path-time curves (also interposed with backward motion) perform leave, whereby a very flexible and if necessary very gentle workpiece machining can be done. However, this increased flexibility allows one and the same forming press can be used without major conversion today for forming sheet metal parts for steel hoods for trucks and tomorrow for aluminum hoods for small cars. The conversion Thus, from a business perspective, a different type of press can be very much desired in order to be able to reshape a component according to the material requirements for different component sizes and materials. This is all the more true because the same effect that was described for a single forming press can also be applied to entire so-called "press lines", as they are today in the metal industry in the area of complex, multi-stage forming processes - for example in large body parts - are common.

On the other hand, it should be noted that, disadvantageously, the old press, which is not to be used, actually represents a very large operational value and therefore represents a waste of proven technology and resources in the scrapping of the old press. Since you can not easily dismantle a larger press machine and elsewhere, for example, after exporting to another country can build elsewhere, large losses in business terms in the transition from an old press to a new press to disadvantageously accept.

It is therefore an object of the present invention is to remedy this situation and to show how you can continue to use cost-saving existing forming machines without having to do without the simultaneous use of modern drive technologies in the form of programmable servo drives.

ADVANTAGES OF THE INVENTION

The subject matter of the respective independent claims solves this problem.

In the dependent claims are advantageous developments and improvements of the respective subject of the invention.

An essential idea of the present invention is to convert an existing forming machine, for example a forming press, whose forming force is generated in a mechanical way such that the existing drive motor, for example a DC or AC motor and the drive train from the electric motor to the flywheel, including clutch between the two elements and - if present - the flywheel is disassembled and a new drive, namely an electric servo drive is connected to the undeveloped shaft of the flywheel via a power transmission mechanism and all aggregates "downstream" seen in the power flow towards the workpiece remain and can be used further. From a technical point of view, the forces from the servo drive can also be transmitted directly to the eccentric shaft. Advantageously, the servo drive is an electrically functioning, freely programmable controllable servo motor.

For further use are thus the eccentric with its socket, possibly the flywheel shaft, the connecting rod, the plunger, and of course the entire press frame available. For example, the servo motor can transmit its power from the motor shaft to the former flywheel mass shaft via one or more V-belts, planetary gears or the like. For this purpose, suitable V-belt pulleys and suitable tensioning devices for this V-belt transmission or another type of power transmission (transmission) are installed according to the prior art. Together with a programmed control for the servomotor, the former flywheel shaft can be selectively rotated, whereby the thus realized rotation of the former flywheel shaft together with the existing eccentric mechanism causes the desired, realizable movement of the plunger.

By this specific replacement of only very specific components of the forming machine, the very strict regulations for a conversion of existing forming machines, in particular of pressing machines for safety-related parts that are virtually unchangeable, can be met: In an advantageous manner, for example, no new brake devices must be installed which require a separate official or TÜV-approved inspection. The default is the EN692 (safety of mechanical presses) and the Machinery Directive according to which a press is declared as attachment 4 machine. The corresponding safety is checked and guaranteed in Germany by the professional association. The EN692 describes the function of a mechanical press and its safety equipment. Here also the mechanical structure and the corresponding equipment (clutch, brake, press safety valve etc.) are documented. Failure to comply with this will violate applicable EU law.

This results in a press with a modern servo drive that can be programmed individually controlled and thus has the above advantages, realized in a functional press frame with existing mechanical periphery, connecting rods, eccentric, eccentric bushing, possibly gears in virtually unchanged press head part and the unchanged press frame ,

1. a) Abbauen einer gegebenenfalls vorhandenen Schwungmasse von einer ggf. vorhandenen Schwungmassenwelle,
2. b) Abbauen eines vorhandenen Motors, der die Schwungmassenwelle oder eine andere Welle antreibt, der Motor ist im Wesentlichen ein Gleichstrom- oder Wechselstrommotor,
3. c) Entfernen der Kupplung zwischen Schwungmassenwelle und Antriebswelle zum Motor,
4. d) Montieren eines elektrischen Servomotors als Antriebsaggregat, im folgenden Servoantrieb (SA genannt),
5. e) Installieren eines Kraftübertragungsmechanismus von dem Servoantrieb auf die Welle der ehemaligen Schwungmasse, bzw. eine andere Welle im Antriebsstrang der Umformmaschine, an einer nachträglich zum Gestell des Kopfteils hergestellten Ankoppelstelle, wobei im wesentlichen alle üblichen, dem Fachmann im Zusammenhang mit der Übertragung von großen Kräften bekannten Kraftübertragungsmechanismen in Frage kommen, zum Beispiel, Keilriemen, Zahnriemen, Zahnräder, Getriebe, und bevorzugt den Schritt:
6. f) Installieren einer die Kinematik der neuen Ankoppelstelle berücksichtigenden Steuerung für den Servoantrieb gemäß den jeweiligen Anforderungen für die Produktion vom Umformwerkstücken.

According to a method aspect of the present invention, a method of retrofitting an existing mechanical forming machine (not hydraulically functioning) is disclosed, which essentially comprises the following method steps:

1. a) Dismantling an optionally present flywheel from an optionally present flywheel mass wave,
2. b) disassembling an existing engine that drives the flywheel shaft or other shaft, the engine is essentially a DC or AC motor,
3. c) removing the coupling between flywheel shaft and drive shaft to the engine,
4. d) mounting an electric servomotor as drive unit, in the following servo drive (called SA),
5. e) installing a power transmission mechanism of the servo drive on the shaft of the former flywheel, or another shaft in the drive train of the forming machine, at a subsequently manufactured to the frame of the head coupling point, wherein essentially all the usual, the skilled person in connection with the transmission of large Force known power transmission mechanisms come into question, for example, V-belt, timing belt, gears, gears, and preferably the step:
6. f) Install a servodrive control that takes into account the kinematics of the new docking point in accordance with the requirements for the production of the forming workpieces.

Thus, according to the invention, forming machines can be retrofitted by connecting a servo motor instead of an existing drive to a location in the drive train for the ram where there is room for, preferably at a drive shaft already existing on the machine prior to the start of the method, such as for example a flywheel or eccentric shaft.

Preferably does not need to be intervened in the other mechanical periphery such as frame, press table, workpiece feed, tool holder, brakes, or the transmission in the head of the machine. Particularly suitable are forming machines, which currently have a particularly massive, valuable and functional periphery, which thus represent a high operational value.
If there is not enough room on an existing shaft, a new shaft can be installed, which provides enough space for the new coupling point.

Alternatively, instead of dismantling the abovementioned components of the forming machine, only a permanent decoupling of these parts from the force flow between the drive motor and the plunger can take place.

Examples of machines according to the invention which can be converted in a particularly suitable manner are eccentric-based forming machines without and with wedge, cf. Dubbel, 22nd ed., T61, Figure 15, spindle-based forming machines where the coupling point for the new drive is on the spindle shaft or on the shaft for driving the threaded body for the spindle, cf. Dubbel, 22nd ed., T65, T66, forming machines with slider-crank mechanism with or without toggle mechanism or steering gear, cf. Dubbel, 22nd ed., T59, picture 8.
The scope of application of the invention includes not only press machines, but also rolling machines and bending machines, as well as cutting and punching machines.
By applying the retrofitting method according to the invention can be saved in an extremely advantageous manner about 80 percent of the cost of a comparable new forming machine. Furthermore, the conversion is faster and easier to carry out than a new acquisition of a comparable machine. Since in the these forming machines applying industry often whole agglomerations of such machines are in use, eg so-called press lines, results from the large number of existing machines a corresponding multiplier factor for the financial savings.

DRAWINGS

Fig. 1

eine schematisch Skizze einer exzenterbasierten Umformpresse, bevor das erfindungsgemäße Verfahren auf diese Vorrichtung angewendet wurde;

Fig. 2

eine schematisch Skizze der Umformpresse aus Figur 1, nachdem das erfindungsgemäße Verfahren auf diese Vorrichtung angewendet wurde, mit einer Ankoppelstelle für den Kraftübertragungsmechanismus an der Schwungmassenwelle;

Fig. 3

eine schematische Gegenüberstellung der Komponenten im Weg des Kraftflusses eine Umformpresse gemäß Figur 1, links vor und rechts nach Anwendung des erfindungsgemäßen Verfahrens gemäß eines Ausführungsbeispiels;

Fi. 4

eine schematische Darstellung des Ablaufs der erfindungsgemäßen Schritte in dem erfindungsgemäßen Verfahren gemäß eines Ausführungsbeispiels;

Fig. 5

eine schematisch Skizze der Umformpresse aus Figur 1, nachdem das erfindungsgemäße Verfahren auf diese Vorrichtung angewendet wurde mit einer Ankoppelstelle für den Kraftübertragungsmechanismus an der Exzenterwelle selbst;

Fig. 6

ein weiteres Ausführungsbeispiel des erfindungsgemäßen Verfahrens, bzw. der erfindungsgemäß ausgebildeten Umformmaschine (rechts) in einem Vorher-Nachher-Vergleich.

Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description.
Show it:

Fig. 1

a schematic sketch of an eccentric-based forming press before the inventive method has been applied to this device;

Fig. 2

a schematic sketch of the forming press FIG. 1 after the method according to the invention has been applied to this device, with a coupling point for the power transmission mechanism on the flywheel mass shaft;

Fig. 3

a schematic comparison of the components in the path of the force flow according to a forming press FIG. 1 , left before and right after application of the method according to an embodiment of the invention;

Fi. 4

a schematic representation of the sequence of steps according to the invention in the inventive method according to an embodiment;

Fig. 5

a schematic sketch of the forming press FIG. 1 after the method according to the invention has been applied to this device with a coupling point for the power transmission mechanism on the eccentric shaft itself;

Fig. 6

a further embodiment of the method according to the invention, or the forming machine according to the invention (right) in a before-after comparison.

DESCRIPTION OF THE EMBODIMENTS

In the figures, the same reference numerals designate the same or functionally identical components.

FIG. 2 shows a schematic sketch of the forming press FIG. 1 After the inventive method has been applied to this device according to an embodiment thereof.

According to this embodiment of the method, the previously existing engine 12 together with the belt drive 14 is reduced to the flywheel 16, see FIG. 1 , As a further step, the flywheel 16 is degraded. As the next step, the clutch 20 is dismantled.

Then, with reference to FIG. 2 According to the invention and according to embodiment of the still existing flywheel shaft 18, an arrangement of a plurality of parallel pulleys 44 attached and firmly connected to the flywheel shaft 18. This is the new coupling point 8 for the programmable Serrvo drive. In a further step, an electric servo motor 40 is fixedly mounted in the vicinity of the pulleys 44, for example on the frame of the press head part, and a belt drive is mounted between the servo motor 40 and the pulleys 44. The belts are held tensioned by a tensioning device, as known in the art, so that any rotational movement of the axis of the servomotor 40 can be transmitted as free of play as possible via the mentioned plurality of belts.

The brake 22 and all others, in FIG. 1 mentioned components are retained. If it should require the kinematics of the desired movement of the plunger, of course, another gear 24 with a newly adapted Sub-gear ratio used to be used before.

The skilled artisan will recognize that advantageously only a few conversion steps are required to from the press according to FIG. 1 equipped with a classic electric motor and flywheel and coupling to make a "modern" servo press, which can now, after the conversion, operated with a controller, which in turn is also known in the art and always adapted exactly to the application of the invention becomes.

The FIG. 3 illustrates once again clearly which components can be retained on the forming device and which components are dismantled or which new components are added. The components indicated in box 50 are dismantled in this embodiment, the components from box 52 are newly added and all other components are retained.

In another embodiment, a modified transmission 24 is installed with a different gear ratio to allow for optimal matching between the kinematics of the servomotor and the kinematics of the eccentric movement.

FIG. 4 shows a schematic representation of the sequence of steps according to the invention in the inventive method according to the above embodiment.

In a first step 410, the flywheel 16 is removed from the flywheel shaft 18.

In a further step 420, the existing drive motor 12 including the belt 14 between flywheel and engine is dismantled.

In a further step, the clutch 20 is disassembled from the flywheel mass.

In a next step 440, the new servo drive is mounted, for example, at the same location of the pre-existing electric motor.

In a next step 450, a power transmission mechanism is mounted between the servo motor 40 and the flywheel shaft 18. In the embodiment shown, this is a belt drive. However, in variation of this embodiment, any other power transmission mechanisms, such as gears, gear connections, etc., may be used and correspondingly, other power transmission elements may be mounted to transmit the forces and movement of the motor axle to the flywheel shaft. The assembly takes place by means of fastening techniques known in the art.

In a next step 460, a control for the servo motor 40 is implemented which exactly meets the requirements required for any specific forming operation. The controller takes into account the possibly new kinematics of the new coupling point 8 for the introduction of force from the servomotor to the coupled drive shaft in the machine head part.

In a further optional step, which is present or not depending on the implementation of the control, a control of the brake 22 is implemented.

FIG. 5 shows a schematic sketch of the forming press FIG. 1 after the method according to the invention has been applied to this device, with a coupling point 8 for a power transmission mechanism (42, 44 on the eccentric shaft 26 itself.

In modification of the in FIG. 2 shown embodiment of an inventively restructured forming device, the power transmission mechanism between servo motor 40 and the eccentric shaft 26 is made in this embodiment itself. That is, the flywheel mass shaft 18 and the brake 22 are degraded, and instead of the brake 22, another brake 46 is installed to brake the eccentric shaft itself. Thus, the new docking point 8 for the programmable Serrvoantrieb is made.

This embodiment can now be changed in a meaningful way, for example, by the fact that the brake 22, the transmission gear 24 and the flywheel shaft 18 still remain in order to meet any existing safety requirements easier.

The FIG. 6 on the right shows the result of a further embodiment of the method according to the invention and on the right side according to the invention restructured forming in a further embodiment, in which a press frame in column construction is available and the existing press device (shown left) with a DC or AC motor 12, Clutch 20 and brake 22 in the drive train and a flywheel 16 as in the first-mentioned embodiment is present. The force is transmitted via an eccentric shaft 26 to the connecting rod and plunger.

Now, however, two synchronized servomotors 40 are mounted on the press frame, after the previously existing engine has been dismantled, including clutch and flywheel. The drive shafts of the newly installed servomotors are in this embodiment directly connected to the eccentric shaft 26 by installing a suitable power transmission system between these shafts. Shown here is a belt drive 42. However, any other suitable power transmission mechanism could be used.

The subject matter of driving the servomotors of the present invention may be implemented in hardware, software, or a combination of both.
This controller may also be embedded in a computer program product.

Although the present invention has been described above with reference to a preferred embodiment, it is not limited thereto, but can be modified in a variety of ways.
In particular, the concrete position of the coupling points for the new servo drives or should be aligned to the specific circumstances of a particular machine to ensure a forming machine in a robust design and for durable, low-wear and low-maintenance operation.

Finally, the features of the subclaims can be combined substantially freely with one another and not by the order given in the claims, provided that they are independent of each other.

Claims (6)

A head part for a forming machine, characterized in that the head part includes a relative to the original state subsequently produced Ankoppelstelle (8) for a power transmission mechanism (42) in one or the only main drive train of the machine, and the power transmission mechanism with a servo drive element (40) is coupled. Head part for a forming machine, characterized in that it can be produced by the method according to claim 4 from an existing forming machine to a servo drive (40), and the head part contains a relative to the original state subsequently produced coupling point (8) for a power transmission mechanism, which with a Servo drive element is coupled. Forming machine with a head part according to one of the preceding claims, comprising a plurality of synchronously operable servomotors as drive elements. Method for converting a head part of a forming machine, characterized by the steps: a) dismantling (410) an optionally present flywheel mass (18) from an optionally present flywheel mass shaft (16), or separating the flywheel mass (18) from the force flow between drive motor and plunger (32), b) disassembling (420) an existing drive motor (12) that drives the flywheel shaft (18) or another shaft (26), the motor (12) being essentially a DC or AC motor, or disconnecting the motor from the power flow between drive motor and plunger, c) removing (430) a clutch (20) for connecting or disconnecting the flywheel during operation of the forming machine, or separating the clutch (20) from the power flow between the drive motor and plunger, or holding the clutch (20) in a disengaged position that interrupts the flow of power, d) mounting (440) an electric servomotor (40) as a drive unit for the forming machine, e) installing (450) a power transmission mechanism (42) from the servomotor (40) to the former flywheel shaft (18), or another shaft (26) in one or the single powertrain of the forming machine, at a docking location retrofitted relative to the original condition (8th). Method according to the preceding claim, further comprising the step: Install (460) a servodrive control taking into account the kinematics of the new coupling point (8) in accordance with the requirements for the production of the forming workpieces. Method for improved operation of a forming machine, characterized in that the following steps have been carried out on the forming machine: a) dismantling (410) an optionally present flywheel mass (18) from an optionally present flywheel mass shaft (16), or separating the flywheel mass (18) from the force flow between drive motor and plunger (32), b) disassembling (420) an existing drive motor (12) which drives the flywheel shaft (18) or another shaft (26), the motor (12) being essentially a direct current or AC motor is, or disconnecting the motor from the power flow between the drive motor and plunger, c) removing (430) a clutch (20) for connecting or disconnecting the flywheel during operation of the forming machine, or separating the clutch (20) from the power flow between the drive motor and plunger, or holding the clutch (20) in a disengaged position that interrupts the flow of power, d) mounting (440) an electric servomotor (40) as a drive unit for the forming machine, e) installing (450) a power transmission mechanism (42) from the servomotor (40) to the former flywheel shaft (18), or another shaft (26) in one or the single powertrain of the forming machine, at a docking location retrofitted relative to the original condition (8th).

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