EP0937572B1 - Press or press plant with electrical drive according to the linear motor principle - Google Patents

Description

The invention relates to a press or press system with an electric drive according to the preamble of claim 1.

Presses, multi-stage presses, high-speed presses and the like the cutting and / or shaping of metallic as well as non-metallic Materials in sheet, plate or the like. Form of strips or strips or the like Semi-finished form. Both high-speed presses come as presses or press systems with high cycle rates and high ram speeds into consideration also presses for forming with increased effort and work capacity than even those with multiple processing stages.

US-A-3,709,083, US-A-4,022,090, US-A-4,135,770, US-A-2,951,437, EP-B1-0554258 are presses or punches with an electrical direct drive published with excitation coils on the frame side and rotor parts on the tappet side. adversely is the mechanical blocking required here with such a drive Ram movement through contact (stops) in the press frame or in the tool.

From US-A-5,357,779 is the use of a linear motor in a press known for returning a tool-side part. This makes it possible Separate movements of forming and ejecting. The pestle itself is from an electric motor via a connecting rod type mechanical connection driven, which rotates the crankshaft of the engine in a reciprocating motion of the pestle changes. Position sensors record the angular position of the crankshaft, to get information about the position of the plunger from a control unit processed to control the force of the ram depending on the path.

GB-A-1,195,649 and FR-A-2,247,344 are forging presses with one Knock hammer known when moving down by a linear motor accelerated to the speed required for the subsequent forging shot becomes. The forging shot itself takes place in the free fall of the hammer, whereby according to the FR-A-2,247,344 to protect the linear motor, it is uncoupled immediately before impact and is only coupled again after the impact.

Furthermore, from US-A-4,155,300 is the use of a linear motor as Alternative known for the auxiliary drive of the ram in a hydraulic press. This is intended to achieve higher stroke rates. The auxiliary drive can either continue to work in the working direction or be switched to idle. The press can use both a standing and vertical ram stroke and a lying press horizontal ram stroke.

From German Offenlegungsschriften DE-A1-41 34 100 and DE-A1-43 41 661 linear motor drive units are known without the magnetic levitation system Reference to their use as drive means for rams moved in presses.

Linear motor drive units consist of a combination of linear guide units and a linear motor. Straight guide units exist, for example from a rail of a given length, on which a carriage or carriage is conveyed Rolling body is displaceable. The linear motor coupled to it is in general a separate unit that is connected to the sled or carriage.

With a linear motor it is possible to direct electrical energy into a straight line To implement movement.

Linear motor drive units are robust compact units in their construction. They represent so-called digital intelligent direct drives, the forces of which today reach up to 14.5 kN at accelerations up to 450 m / s ² and speeds up to 300 m / min.

The extensive state of the art did not lead to constructive solutions with regard to the drive movement of rams in presses or press systems. The The prior art also shows that the use of linear motor drive units is conceptual runs in a different direction.

From the publication "Research Development Teaching" by the Institute of Production Technology and forming machines, Technical University Darmstadt, published Darmstadt 1997, page 43, is a linear motor punching unit under alternative machine concepts known. Tool lower parts are attached to a base plate. this are opposed to tool upper parts, each of one secondary part of one (of two) Linear motor are attached. The linear motor punching unit works without a plunger, so only with small mass. Thereafter, linear motor punching units can be used for Shear cutting, also in connection with other forming processes. The article goes from small, modular cutting and forming units. As advantages viewed here that press drives with linear motors advantages hydraulic and mechanical presses unite, but without the actual ones, out of motion larger masses, e.g. a pestle presents resulting problems, such as mass balancing and weight compensation, position control during forming, constructive redesign the presses u. Like. To mention.

In contrast, it is an object of the invention in presses for cutting, punching and / or forming workpieces linear motor drives as the main drive of to integrate one or more plungers.

This object is achieved by the characterizing features of claim 1.

In general, the design of the presses needs to be redesigned. The installation the linear motor drives between the press frame (press stand) and the ram are obstructed not the use of any linear guides that may be required Press frame and ram.

It is particularly advantageous that both bound and force-bound and understand energy (work) bound characteristics by using the corresponding size as a reference in the control or control of the drives.

The invention uses the idea for directly operated, as well as for indirect operated plunger.

Another special advantage is the possibility of multiplying the force for major cutting and forming work and the additional feed and adjustment of energy during the forming process.

As a result, ram strokes of different heights, punching and forming speeds Actuators for a separate immersion depth control were often required. This can now be omitted due to the reproducible high accuracy in the Travel movement of the linear motor drives.

The tappet can be moved freely in its travel-time criteria. Elaborate mechanical cam and / or articulated drives, with which only from specified characteristics can be achieved.

Furthermore, the problem of tappet tilting is compensated for by the invention, the resultant migratory load during forming or uneven load is caused. Through the use (installation) of several linear motor drives at different ram areas can be controlled via a sequence control between the drives compensate the tappet tilt over the duration of the intervention.

Another special advantage is the possibility of balancing mass forces tapped directly from the ram or alternatively by a linear motor-operated Dimensions.

It is regarded as essential to the invention that there are several linear motors common rotor part (secondary part) or stator part (primary part) integral with the Press frame can be used for several linear motor drives. This secondary part or these primary parts can, or can be so for the linear motor drives Plunger and at the same time advantageous for the linear motor or the balancing mass form.

These and other advantages effect the features of claim 1 and in the further claims preferred characterized embodiments.

These will be explained in more detail below with the aid of the drawing.

Fig. 1

eine erste Presse, teilweise im Schnitt, mit Linearmotor-Antrieben,

Fig. 2

die Presse entsprechend einem gedachten Schnitt oberhalb des in Fig. 1 gezeigten Stößels,

Fig. 3

eine zweite Presse mit einem mechanisch mit dem Stößel wirkverbundenen Massenausgleich,

Fig. 4

die Presse entsprechend einem gedachten Schnittverlauf in Fig. 3 im Bereich des Massenausgleiches,

Fig. 5

eine Presse mit Stößel und Massenausgleich, angetrieben von gemeinsamen Linearmotor-Antrieben,

Fig. 6

eine Presse mit Stößel und Massenausgleich, angetrieben von getrennten Linearmotor-Antrieben und

Fig. 7

eine Antriebssteuerung für den Massenausgleich.

Show

Fig. 1

a first press, partly in section, with linear motor drives,

Fig. 2

the press according to an imaginary section above the ram shown in Fig. 1,

Fig. 3

a second press with a mass balance mechanically connected to the ram,

Fig. 4

the press corresponding to an imaginary section in Fig. 3 in the area of mass balancing,

Fig. 5

a press with ram and mass balance, driven by common linear motor drives,

Fig. 6

a press with ram and mass balance, driven by separate linear motor drives and

Fig. 7

a drive control for mass balancing.

The advantages of using linear motor drives come from both work-related ones Presses, such as screw presses or forging presses also with tied or force-bound presses, such as mechanical presses or hydraulic presses to carry. The possibilities according to the invention include the geometric arrangement of several linear motor drives in each drive area, which leads to multiplication of power with electrical parallel connection. Preferred application were initially high-speed presses with high cycle rates and high ram speed. The invention is on such presses for cutting and punching is not restricted, since in addition to power-bound, there are also away or energy-bound Characteristics can be realized and the invention thus also for presses is to be provided for forming.

The press in Figs. 1 and 2 has a press frame 1 made of a welding or Cast construction with a press table 2 for receiving and supporting a Lower part of a tool or tool set 4. In the opening area of the Press is a press ram 3 mounted in guides 8 up and down. It understands yourself that with a lying press the press ram 3 then horizontally and between to move its reversal points. Serve to drive the press ram 3 Linear motor drives 5 between the press frame 1 and press ram 3 essentially are integrated in the area of the guides 8.

Positions 6 and 7 are primary and secondary parts of one or more Linear motor drives are provided for each drive area. Primary and secondary parts are interchangeable. However, in the embodiment shown, the press ram side Primary parts 6 or the like via cable towing. Energy supply means are supplied. In the exemplary embodiment shown, the secondary part extends over the total movement length of the press ram. In the case of replacement, there are instead of the secondary part Primary parts in a number corresponding to the length.

As can be seen in particular from FIG. 2, the linear motor drives are located 5 essentially in the area of the guides 8, in individual cases on guides, integral with the press, can be dispensed with when using e.g. in DE-A1 41 34 100 described linear motor drive units. These have management tools on with rolling element between rail and movable slide part.

The figures 3 and 4 show an embodiment according to FIGS. 1 and 2, where the press ram 3 mounted in the guides 8 by means of linear motor drives is movable. In the head area of the press 1 there are two leveling compounds in one bearing point 14 rotatably mounted, each distant from the bearing point 14 Area about deflection means 10 are articulated from the handlebars 11 and bracket 12. The handlebars 11 are mounted on the frame side in pedestals 13; the tab 12 is at the other end Press ram 3 articulated.

Fig. 4 shows in detail the double arrangement of links 11 and tabs 12 and the pedestals 13.

5 is another embodiment of a press with a press frame 1, Press table 2 and the press ram 3 mounted in guides 8 are shown. In the head area the balancing mass 16 is movably mounted in guides 20 - accordingly the extension of the guides.

On an intermediate support 25 are linear motor drives 15 transverse to the direction of movement of the press ram 3 slidably arranged, one of which several linear motor drives is shown.

The linear motor drive 15 shown is on the one hand with a tab 17 with the Press ram 3, on the other hand with a tab 17, e.g. in the same version with the Compensation mass, operatively connected in pivot bearings 19 and 18. Mechanically with the press ram leveling compounds, their meaning, structure and arrangement are described, for example, in EP-B 1-455 988. It is understood that corresponding to the number of articulation points 18, 19 on balancing mass 16 and Press ram 3 at least one linear motor drive 15 is provided, the other Linear motor drives are electrically and force-wise connected in parallel.

6 shows a press ram 3 in a press frame 1 of a press and a mass balance 21, which are mechanically separated from each other. The press ram 3, as in the manner shown above, by means of linear motor drives 5 the primary and secondary parts 7, 23 operated. The primary parts 23, for example here are integrated on the press frame side, extend over the movement length of the Press ram 3 in the range of motion of the balancing mass 21 with the Secondary part 22. Press ram 3 and leveling compound 21 can be in the same guide means 8 be slidably movable. An advantage of the arrangement of the primary parts 23 in the press frame side of the press is opposite to a counterpart Arrangement in the avoidance of cable drag for the control of the Linear motor drives can be seen.

In the following, the circuit structure of a drive concept shown in FIG. 7 is intended with mass balancing drives are briefly explained. Generally, controls fundamentally offered by the suppliers of linear motor drives. The required control is a multi-stage position control, speed control, as well as current (force) acceleration control.

The tappet drive requires a precise specification of the tappet travel-time characteristic as a control curve. The drive control follows a control strategy based on a Set-actual comparison of the position, the speed and the current builds up. The one shown Press 1 shows a linear scale query 24 for the target-actual comparison of Ram position in comparison point 26 and speed in comparison point 27, where both the target and the actual value of the speed by numerical differentiation the location can be determined. The control of the speed goes Actual speed value on, the speed setpoint after the control curve (Speed pre-control) as well as the speed after position control. The Current control receives target speed and actual current as input variables. Now the commutation of the current and the power amplification takes place for the drive of the plunger. The leveling compound must track the ram accelerations, not their way, why the speed specifications in 32 continuously tapped and with those of the previous step. It should be noted that the Path of the balancing mass is limited, so the position of the plunger in the control of the Compensation mass must find entry. For controlling or loading the Linear motor drives 22 of the mass balance 21 arranged here in the press table 2 serves another control loop with the components acceleration calculation 28, current controller 29, commutation 30 and a power section 31.

Claims (13)

1. Press or pressing plant with a press body (1), a press bed (2) and at least one press ram (3) to receive tool bottom part(s) (4) or tool top part(s) (4), wherein the at least one press ram (3) is disposed in the press body (1) to be movable up and down or back and forth and is driven by an electric drive, which has at least one linear motor (5, 6, 7, 15, 23) as main drive means, which is disposed inside the press body (1) and, with respect to the driving action, between this and the press ram (3), characterised in that the at least one linear motor (5, 6, 7, 15, 23) is controlled/adjusted in such a manner that a displacement-controlled movement of the ram actuated by the linear motor (5, 6, 7, 15, 23) is achieved during the processing of a work piece.
2. Press according to Claim 1, characterised in that the linear motor or motors (5, 6, 7) are disposed as direct drives in the region of guide means (8) for guiding the press ram (3) on the press body (1).
3. Press according to Claim 2, characterised in that the guide means (8) between the press body (1) and press ram (3) are replaced by linear motors (5, 6, 7).
4. Press according to Claim 1, characterised in that at least one linear motor (15) is provided, which acts indirectly on the press ram (3) via movement deflection means.
5. Press according to Claim 1 or 2, characterised by several linear motors (5, 6, 7, 22, 23), which are preferably disposed in the region of each guide means (8) between the press body (1) and the press ram (3).
6. Press according to Claim 1, characterised in that a rotor part (7) common to several linear motors (5) on the press body (1) extends between this and the press ram (3) over the entire movement path of the press ram (3) and the stator part (6) or stator parts is/are disposed on the press ram (3) or is/are integrated into this.
7. Press according to Claim 1, characterised in that a rotor part (7) common to several linear motors (5) extends between the press body (1) and the press ram (3) beyond the entire movement path of the press ram (3) for main and auxiliary drives.
8. Press according to Claims 1, 6 or 7, characterised in that the stand parts (6) of several linear motors (5) extending over the movement range of the press ram (3) and beyond this are integrated on the press body side and the secondary parts (7) are integrated on the ram side.
9. Press according to one of Claims 7 or 8, characterised in that in the region of the linear motors (5) extending beyond the movement path of the press ram (3), a compensating mass (21) is displaceably disposed on the press body side, the integrated linear motors (22, 23) of which can be driven either directly or via a sequential control in master-slave operation to the ram drive.
10. Press according to one of Claims 7 or 8, characterised in that in the region extending beyond the movement path of the press ram (3), a compensating mass (9) is movably disposed on the press body side, which is mechanically actively connected with the press ram (3).
11. Press according to one of Claims 1 or 4, characterised in that at least one linear motor drive (15) is arranged, which is actively disposed transversely to the direction of movement of the press ram (3) and is provided with deflection means (17, 18) for deflection of the movement between the linear motor (15) and the press ram (3).
12. Press according to Claim 11, characterised in that the movements both for the press ram (3) and for the compensating mass (21) are tapped by one, possibly several, joint linear motors (15).
13. Press according to one or more of Claims 1 to 8, characterised in that several linear motors (5, 6, 7) are provided, which are controlled either directly in parallel operation or in master-slave operation.

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