EP2329944A2 - Press for producing pressure for processing a workpiece - Google Patents

Abstract

The press (1) has a press frame (12), and a drive designed as a linear-electric motor (20) and driving a plunger, where the motor is integrated in a press table (10). The electric motor has multiple magnetic positive or negative poles that are arranged and shifted to each other. The poles are formed by coils extending around an axis. The coils are axially arranged and shifted to each other with respect to the axis. A drive shaft of the electric motor extends in a direction of the axis and is linearly adjustable in the direction of the axis by the coils of the poles.

Description

The invention relates to a press for generating a pressure force for the machining of a workpiece.

Presses are already known in various embodiments. Such presses are used to generate a compressive force for the machining of a workpiece. They are used for example in stamping machines or in thermoforming or cutting machines. In general, presses on a press table, a press frame, a plunger and a drive for driving this plunger on.

Examples of known presses are the so-called tryout presses or the so-called hydraulic presses.

Another known type of presses are the so-called eccentric presses. Eccentric presses have a drive with a rotationally driven drive shaft, wherein this rotating drive movement of the drive shaft is converted into a linear movement of the tappet. For the purpose of this conversion, eccentrics are typically used.

Another possibility for generating the required linear movement of the plunger is that a linear drive is formed by means of a spindle. For this purpose, a rotationally driven shaft, such as the drive shaft of a motor, is converted by means of the spindle into a linear movement.

The designs with drive systems of the latter type are therefore based, just like the drive systems of eccentric presses, on the fact that a rotating movement is converted into a linear movement. In this conversion of the rotational movements in linear movements, however, occur appreciable energy losses or friction on (in particular by gear and spindle ratios) which or that, however can be counteracted by the use of lubricating oils, which, however, cause additional costs. Presses of the known type often require several hectoliters of lubricating oil in relatively short time units.

From the EP 0 943 422 A2 In addition, a press is known which uses four linear electric motors as drives. These linear electric motors each have a magnetic plate and a coil plate, which are arranged laterally next to the magnetic plate and the linear driving of the magnetic plate is used. The longitudinal direction of these plates in the vertical direction, and the plates are positioned laterally of the working area which is formed between the press head and the press table, in such a way that on two opposite sides in each case two linear electric motors are arranged. Between the two each arranged on the same side linear electric motors each type of window is formed. These fixtures seem to serve to allow the material to flow in and out of the work area.

Such, according to the EP 0 943 422 A2 provided linear electric motors having a magnetic plate and a coil plate, typically have a fairly large areal extent and complicate the design according to the EP 0 943 422 A2 the accessibility of the work area. Depending on the specific embodiment, this may, for example, lead to the consideration that the supplied and discharged material is only such that has particularly small dimensions transversely to the material flow direction. In addition, when designing according to the EP 0 943 422 A2 for the large-area magnetic disks corresponding linear guides are required, which may possibly cause a corresponding lubricant (more) required. The from the EP 0 943 422 A2 known magnetic fields are usually very strong, so that health problems for the staff, especially if they carry a pacemaker, threaten.

Accordingly, the invention is based on the object to provide a press with low lubricant consumption and / or low energy losses, which allows a good and possibly operationally adapted space utilization.

According to the invention, a press according to claim 1 or according to claim 7 is proposed. Examples of such a press can be taken from the subclaims and the following description.

According to the invention, therefore, a press is proposed for generating a compressive force for the machining of a workpiece, which has a machine table or press table, a machine frame or press frame, a plunger and at least one drive for driving the plunger. This drive of the plunger, or more or all drives of the plunger are formed as a linear electric motor. The, several or all linear electric motors have a plurality of mutually offset magnetic poles and a means of these poles linearly displaceable part, such as drive axle, on. The magnetic poles of at least one linear electric motor are formed by coils extending around an axis which are axially offset with respect to this axis. The linearly displaceable part extends in the direction of this axis and is linearly displaceable by means of the coils in the direction of this axis.

For the purposes of the present application, the term "workpiece" is to be understood broadly. For example, a workpiece can be an isolated workpiece or, for example, also contiguous material that is separated, for example by cutting, punching or the like.

The machining of the workpiece can also take place in various ways in the sense of the present invention. For example, the processing may consist in a "deep drawing" or a "cutting" or a "punching".

Accordingly, the press according to the invention may for example be part of a thermoforming machine or a punching machine or a cutting machine or another type of machine in which a pressure force for machining a workpiece is required.

In an advantageous embodiment, the linear electric motor is designed as a servo motor. In particular, the linear electric motor may be designed such that its linearly displaceable part is a drive axle which projects into or is arranged in a magnetic field or a plurality of magnetic fields of the linear electric motor and can be moved axially by means of the magnetic field or fields. This can in particular be such that the linearly displaceable part or drive axle can be moved axially back and forth by means of the magnetic field (s). The drive shaft or the linearly displaceable part is therefore in particular a kind of core of the electric motor, which is axially movable. These magnetic fields are formed in particular by the poles. The coils can in particular be current-carrying or are current-flowed through to effect the corresponding magnetic poles.

It can be provided that the plunger is coupled to at least one first tool or a plurality of first tools, and in particular is directly coupled. For this purpose, a first tool holder for receiving the first tool can be provided on the plunger. The first tool holder may for example consist of a plurality of grooves, in particular T-shaped grooves.

It can also be provided that a second tool holder for receiving at least one second tool is provided on the press table. For this purpose, the press table, in particular the upper surface or table top of the press table, one or more second tool holders for receiving a second tool. The second tool holder may for example consist of a plurality of grooves, in particular T-shaped grooves.

The press table can, in particular on its upper side, be provided with one or more guide devices and / or with one or more holding devices for guiding or holding the workpiece. These can for example be detachably mounted.

For the example of deep drawing, for example, a first tool may be a stamp and a second tool may be a drawing ring or a die. Another second tool may be a hold-down.

It can be provided that the force transmission path between the linear electric motor or its linearly displaceable part or its drive axis and the plunger or the first tool or the first tool holder is free of rotating parts. A linearly displaceable part of the linear electric motor or a drive axis of the linear electric motor - ie in particular an axis which projects into the one or more magnetic fields of the electric motor and is driven by or from this - can be coupled directly to the plunger. This can for example be such that the addressed drive axle or the addressed linearly displaceable part and the mentioned plunger are connected to each other directly via a screw or the like. It can also be provided that a bolt or a bolt arrangement produces such a direct connection.

According to an alternative embodiment, a coupling between a linearly displaceable part or a drive axis of a linear electric motor and the plunger also indirectly, for example via a toggle, done. Such a toggle lever may in particular be pivotally mounted, for example pivotally mounted on the press table or on the press frame. It should be noted that in particular it is provided that such a toggle overruns in operation a pivoting range, which is less than 360 degrees, in particular less than or equal to 270 degrees, in particular less than or equal to 180 degrees, in particular less than or equal to 150 degrees, and for example in the range of 120 degrees up to 130 degrees. Smaller angles or paths in the pivoting direction that are traveled by the toggle lever can also be provided.

In this context, it should be noted that - as far as in the context of the appreciation of the prior art was spoken of that there rotating parts are provided, this is in particular such that the rotating parts, in particular several times consecutively, over an angle, the larger or is equal to 360 degrees, so perform complete revolutions.

The linear electric motor can be arranged above the press table. This may for example be such that the press has a press head, which is arranged above the press table and spaced from this press table, in particular vertically, and in which the linear electric motor is integrated. It is particularly provided that (vertically) between the press table and the press head, a work area for the machining of workpieces is formed.

The plunger is arranged in particular above the press table. In an arrangement of the linear electric motor above the press table can be provided in particular that the plunger between the workpiece or the first and / or second tool holder and the linear electric motor is arranged.

It can also be provided that the linear electric motor is integrated in the press table. This can for example be such that the workpiece or the first and / or second tool holder is arranged between the plunger and the linear electric motor. Such a configuration, in which the linear electric motor is integrated in the press table or is arranged below the table top or upper table surface of the press table, has the particular advantage that such a configuration can save upwards space.

It can be provided that the or a drive axle or one or the linearly displaceable part of the linear electric motor is located parallel to the thrust direction of the plunger. But it can also be provided that such a drive axis of the linear electric motor is located transversely, in particular perpendicular, to the thrust direction of the plunger. In an embodiment in which the drive axis of the linear electric motor is located perpendicular to the thrust direction of the plunger, the power transmission from the linearly displaceable part or the drive axle on the plunger can be done for example by means of wedge surfaces or by means of a toggle lever. It can be provided that the plunger is provided with guides, such as linear guides. For example, four linear guides may be provided for the plunger. However, it can also be provided that more than four linear guides or less than four linear guides are provided for the plunger. The plunger may be such that the height of this plunger in the direction of the impact direction of the plunger is less than the width of the plunger extending perpendicularly to this impact direction and / or perpendicular to this width and perpendicular to this thrust extending depth of the plunger. The plunger may for example have an outer contour that is substantially rectangular or substantially square. It may be provided that the plunger has stiffeners to prevent or at least reduce the risk that the plunger undergoes deformations under load.

It may be provided that the press to prevent the breakdown of the plunger in the absence of power to the linear electric motor has a hold-brake for the linearly displaceable part or for the drive axle.

Such a holding brake may for example be designed as a positive brake or as a frictional brake, wherein a combination of these types of brakes may be provided. For example, the brake may have a positive or frictional forceps with two brake shoes, which can embrace the linearly displaceable part or the drive axle. It can also be provided that a tooth is arranged on the linearly displaceable part or on the drive axle, which cooperates with a rack for braking. It can be provided that the rack is spring-actuated in the direction of the tooth or a tooth / rack engaging position is pressed, for example, an electric motor that may be different from the at least one drive of the plunger or the linear electric motors or a drives of Tappet or this linear electric motors, against the spring force exerts a force on the rack to hold them in a disengaged position with the tooth. Then, when the power supply is interrupted, cracked by the intended for the holding brake electric motor, which may also be linear electric motor, exerted on the rack force from, so that the rack under the action of the spring force with the linear on the displaceable part or arranged on the drive axle teeth is engaged and prevents axial displacement of this linearly displaceable part or this drive axle. As a result, the penetration of the plunger (coupled to the linearly displaceable part or to the drive axis) is prevented, that is to say the occurrence of a substantially unrestrained plunger movement in the direction of the press table.

In the alternative embodiment of such a holding brake with positive or frictional forceps and two brake shoes can also act on the brake shoes, which are held in a disengaged position by means of an electric motor provided for the holding brake in a corresponding manner in a disengaged position, as long as the power supply is given. In the absence of power supply, the brake shoes move to the linearly displaceable part or to the drive axle and keep them in their axial position.

A holding brake can be designed, for example, hydraulically or mechanically. This is in particular such that, when power is removed, the hold-up brake is moved from a released position to a braking position to prevent continued movement of the linearly displaceable part or the drive shaft or the plunger.

In embodiments in which the linear electric motor is integrated in the press table, it can be provided that an angle element - in particular fixed - is formed or formed on the plunger via which one or the linearly displaceable part or the or a respective drive axle coupled with the plunger. In the presence of a plurality of linear electric motors, which are integrated in the press table, may be provided in particular that a plurality of such angles are provided. As already mentioned, the drives can or drive units be mounted from above or from below, so that a pushing or pulling movement is exerted on the plunger. The drive or electric motor or the drive units or drives can also be freely selected with regard to the number or position. For example, a drive can be arranged centrally (from) above or three drives or linear electric motors can be arranged centrally above or from above. But it can also be provided that one, two or three linear electric motors are arranged below or from below. Furthermore, it can be provided that four drives or linear electric motors are arranged at the top or from above or below or from below. Furthermore, it is provided that four drives or linear electric motors and additionally a linear electric motor are arranged centrally (from) above. But it can also be provided that eight linear electric motors are arranged above or from above or below or from below. It should be noted that this number of linear electric motors is not intended to limit the invention. It can be provided, for example, any integer number of linear electric motors, each of which is arranged from above or above or from below or below, so in particular integrated into the press table. For example, 5 or 6 or 7 or 9 or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 or 22 or 22 or 23 or 24 linear electric motors may be provided. Also, a higher number of linear electric motors can be provided. Combinations of linear electric motors, which are arranged above the press table, and linear electric motors, which are integrated in the table, can be provided. The drives or drive units or linear electric motors can drive toggle as a power amplifier. By means of a toggle lever system, for example, a horizontal attachment can also be made possible, that is to say in particular also horizontal Arrangement of the drive axle or drive axles of or the linear electric motor or -Elektromotors.

It can be provided that several or all linear electric motors are coupled with exactly one plunger in order to drive it.

In the context of the disclosure of the present invention, the arrangement or the design or the like of a (serving as a drive for the plunger) linear electric motor, in particular exemplified explained in part. However, it is also possible to provide a plurality of linear electric motors each serving as a drive for the same ram. In this case, each of these multiple linear electric motors may be formed and / or arranged as the aforementioned a linear electric motor, provided that this does not reveal obvious contradictions. Furthermore, it can be provided that these several each serving as a drive for the same ram linear electric motors are different and / or arranged, in particular, is provided that different exemplary inventive designs of the linear electric motors are combined. It can further be provided that a plurality of plungers are provided, for the drives of which, in each case, what is said applies.

It can also be provided that the center of gravity, in particular the center of gravity, of each linear electric motor is arranged in the press head or in the press table. Furthermore, it can be provided that the centers of gravity, in particular the centers of gravity, of all linear electric motors are arranged in the press head. It can also be provided that the center of gravity, in particular center of gravity, of all linear electric motors are arranged in the press table. It can further be provided that the center of gravity, in particular the center of gravity, of the entirety of all linear electric motors in the Press head is arranged or arranged in the press table.

The linear electric motors are in particular such that their coils envelop the respective linearly displaceable part or its respective drive axis. It can be provided that the one or more linear electric motors are each rotationally symmetrical.

The or the linearly displaceable parts or drive axles are in particular magnets, in particular permanent magnets, or magnetic.

Fig. 1

eine dreidimensionale Schrägansicht einer ersten beispielhaften erfindungsgemäßen Ausführungsform von oben;

Fig. 2

eine dreidimensionale Schrägansicht der Gestaltung gemäß Fig. 1 von schräg unten;

Fig. 3

eine dreidimensionale Schrägansicht entsprechend der Gestaltung gemäß Fig. 1;

Fig. 4

eine Frontansicht der Gestaltung gemäß Fig. 1;

Fig. 5

eine Seitenansicht der Gestaltung gemäß Fig. 1;

Fig. 6

eine Draufsicht der Gestaltung gemäß Fig. 1;

Fig. 7

eine Schnittansicht entlang der Linie A-A aus Fig. 6;

Fig. 8

zwei Linear-Elektromotoren der erfindungsgemäßen Gestaltung gemäß Fig. 1 bis 7;

Fig. 9

den Stößel der Gestaltung gemäß den Fig. 1 bis 8;

Fig. 10

eine Seitenansicht einer zweiten beispielhaften erfindungsgemäßen Ausführungsform der Erfindung;

Fig. 11

einen beispielhaften Linear-Elektromotor in Frontansicht, der bei bei der Gestaltung gemäß Fig. 1 bis 9 oder bei der Gestaltung gemäß Fig. 10 als Antrieb für den Stößel eingesetzt werden kann;

Fig. 12

Schnitt entlang der Linie XII-XII aus Fig. 11; und

Fig. 13

einen Schnitt entlang der Linie XIII-XIII aus Fig. 11.

Embodiments of the invention will now be explained in more detail with reference to the attached figures, whereby the invention should not be limited, however. Showing:

Fig. 1

a three-dimensional oblique view of a first exemplary embodiment of the invention from above;

Fig. 2

a three-dimensional perspective view of the design according to Fig. 1 from diagonally below;

Fig. 3

a three-dimensional oblique view according to the design according to Fig. 1 ;

Fig. 4

a front view of the design according to Fig. 1 ;

Fig. 5

a side view of the design according to Fig. 1 ;

Fig. 6

a plan view of the design according to Fig. 1 ;

Fig. 7

a sectional view taken along the line AA Fig. 6 ;

Fig. 8

two linear electric motors of the inventive design according to Fig. 1 to 7 ;

Fig. 9

the ram of the design according to the Fig. 1 to 8 ;

Fig. 10

a side view of a second exemplary embodiment of the invention according to the invention;

Fig. 11

an exemplary linear electric motor in front view, the in accordance with the design according to Fig. 1 to 9 or in the design according to Fig. 10 can be used as a drive for the plunger;

Fig. 12

Section along the line XII-XII Fig. 11 ; and

Fig. 13

a section along the line XIII-XIII Fig. 11 ,

The press 1 according to the Fig. 1 to 9 has a press table 10, a press frame 12, a machine head or press head 14 and a plunger 16. The machine head 14 may also be referred to as the machine upper part or press upper part.

The press frame 12 has four columns 18 in the present embodiment.

Above the press table 14, and integrated in this embodiment in the press head 14, a plurality of drives 20 are provided, which are each here as a linear electric motor 20, and in particular designed as a servomotor linear electric motor, are formed.

How good the Fig. 1 can be removed, 14 chambers 22a, 22b, 22c and 22d are formed in this embodiment in the press upper part or press head, in each of which one of the linear electric motors 20 is arranged. In this embodiment, four linear electric motors 20 are provided, but the number may also vary.

It should also be noted, which is not shown in the figures, that the linear electric motors 20 can alternatively also be integrated in the press table 10, as a result of which installation space can be saved upwards. A lateral arrangement of the linear electric motors 20 may alternatively be provided.

The columns 18 of the press frame 20 are arranged on the four corners of an imaginary rectangular contour.

The columns 18 are here so that they carry the press head 14.

How good the Fig. 8 can be removed, the linear electric motors 20 each have a designed as a drive axis 24 linearly displaceable part, which can be moved axially during operation of the linear electric motor 20 and axially moved back and forth, in particular by means of a or a plurality of magnetic fields or by means of a plurality of magnetic poles of the linear electric motor 20th

In this embodiment, an eye 26 is provided on the linear electric motor 20 far end of the drive shaft 24, wherein this eye 26 of the coupling with the plunger 16 is used.

The plunger 16 has a substantially rectangular outer contour and is designed so that it ensures the best possible rigidity. In the exemplary embodiment, this is so that four plates 28, 30, 32, 34 which are essentially height-related form a kind of rectangular frame, the parallel plates 32 and 34 forming short sides and the parallel plates 28 and 30 forming long sides of a rectangle , However, the short sides 34, 32 may be longer than the spacing of the plates 28 and 30, so that the Plates 32, 34 end over the plate 28 and 30 protrude.

For further stiffening triangular plates 36 are formed on the respective abutting plates in the region in which each of the shorter plates 32, 34 project beyond the plates 28, 30. In the exemplary embodiment shown, this is such that three triangular plates 36 are integrally formed in each of these corner areas, one bottom, one top and one substantially in the middle being formed. Moreover, for further stiffening within the frame formed by the plates 28, 30, 32, 34 plates 38, 40 are provided, which here connect the plates 32 and 34 and, for example - as in Fig. 9 shown - parallel to the plates 28 and 30 run. It could, however, also be provided, for example, that stiffening plates in the manner of a truss pattern are arranged within the frame. On the one hand, if necessary for further reinforcement, but on the other hand also for receiving the eyes 26, a bolt extends through two plates for each of the linear electric motors 20. This is so here that two bolts 42 are respectively mounted in the plate 30 and the adjacent plate 40 and two bolts 42 are respectively mounted in the plate 28 and in the adjacent plate 40. In this state, these bolts 42 each extend through an eye 26 of a linear electric motor 20th

The plunger 16 further includes a bottom plate 44 which Fig. 2 can be seen. The bottom plate 44 has a first receiving area 46 for receiving a tool, not shown. The receiving region 46 has a plurality of grooves 48, which are designed T-shaped in this embodiment.

In a corresponding manner, the press table 10 or the press table top has a second receiving area on its upper side 50 for a second tool, which is also not shown. This second receiving region 50 is formed by a plurality of grooves 52, which for example likewise have a T-shaped cross-sectional profile, or has such.

If, which is not shown in the embodiment, the linear electric motors 20 are positioned in the press table 10, for example, corresponding power transmission paths, which are formed for example by L-shaped parts and which provide the coupling to the plunger, in the region of the press frame or run between the columns of the press frame.

An advantage of in the Fig. 1 to 9 shown design can be avoided by the formation of the drive as a linear electric motor 20 and the drives as linear electric motors 20 shocks in stock, since the magnetic field of the linear electric motor 20 acts on the drive axle 24 as a kind of spring. It may be provided that the kickback energy is fed back, resulting in a further improved energy savings.

The in the Fig. 1 to 9 The design shown can be, for example, part of a stamping machine or part of a cutting machine or part of a thermoforming machine. At least in further developments, the invention has various advantages. So it offers a high variability, that means in particular a freely programmable ram speed in every position. Furthermore, tryout operation is possible. Moreover, the design can be used according to a Exzenterstanzautomat or according to a hydraulic press. It is also advantageous that no more synthetic lubricating or hydraulic oils are required. Next occur no rotating bearings, so no lubrication required is. It should be noted that, however, if, for example, in the area of a toggle lever some lubrication is required, this can be effected for example with fats that need not be renewed during the life of the press or usually need not be renewed (life lubrication). Furthermore, the maintenance cycles are extended. Moreover, the invention offers a high degree of variability, at least in its developments. In particular, the linear movement of the plunger 16 is realized directly by a linear movement of the drive. There is no or no conversion of a rotational to a linear movement. Thus, less energy losses occur. Further, the operation of a stamping machine with the waiver of hydraulic and lubricating oils, but with substantially all the advantages of a tryout and / or eccentric and / or hydraulic press enabled by the invention.

Fig. 10 shows a second embodiment of the invention in a schematic view, wherein like or corresponding parts are provided with the reference numerals, which are also in the Fig. 1 to 9 were used.

The design according to Fig. 10 corresponds essentially to the design according to the Fig. 1 to 9 so that on the Fig. 1 to 9 subject to the following deviations also for the design according to Fig. 10 applies.

In the design according to Fig. 10 is the arrangement of the linear electric motors 20 - here, for example, four may be provided - different from the design according to the Fig. 1 to 9 not in the press head 14, but in the press table 10, so that the corresponding power transmission path to the plunger 16 is modified accordingly. Here, the drive shaft 24 is connected to an angle 60 which engages laterally in the plunger 16. In principle, however, the drive axle 24 without Interposition of an angle be connected directly to the plunger 16, for example, laterally or from below.

In the exemplary embodiments of the invention, there are fewer health problems for persons than in the design according to him EP 0 943 422 A2 because the magnetic fields do not have to be that strong. In addition, according to the invention, the magnetic fields can be easily shielded. Furthermore, embodiments of the invention can be made oil and / or fat free.

The arrangement of the linear electric motors 20 in the press table 10 usually saves space upwards. The power transmission path from the linear electric motor 20 to the plunger 16 can be formed for example by the drive axle 24 and / or rods, so that the access to the working area 62 not appreciably, or at least to a lesser extent than in the design according to the EP 0 943 422 A2 , is impaired.

It should be noted that the various advantages and effects that have been described need not necessarily be present in all embodiments of the invention, especially not in combination. In other words, these advantages and effects are not to be understood as meaning that configurations that do not have any or all of these advantages should not form part of the invention. The claimed in the claims designs so do not necessarily require one or more of the aforementioned advantages or effects.

The Fig. 11 to 13 show an exemplary linear electric motor 20, the inventive designs, such as in the design as a drive for the plunger 16 can be used in the Fig. 1 to 9 is shown, or in the design, in Fig. 10 is shown.

Fig. 11 is a front view of the linear electric motor 20, while Fig. 12 a section along the line XII-XII Fig. 11 shows and while Fig. 13 a section along the line XIII-XIII Fig. 11 shows.

The linear electric motor 20 has a plurality of magnetic poles 70, 72, 74, 76, 78, 80, which are arranged offset axially relative to the central longitudinal axis 82 of the linear electric motor 20.

These poles 70, 72, 74, 76, 78, 80 are formed by means of coils 84, 86, 88, which are also arranged axially offset with respect to the central longitudinal axis 82.

Each of these coils 84, 86, 88 is wound on a bobbin 90, 92, 94 on its radially outer surface.

Further, each of the coils 84, 86, 88 are traversed by an electric current and is accordingly made of suitable, electrically conductive material, such as metal, in particular copper. In particular, each of the coils 84, 86, 88 is wound from a corresponding wire.

The magnetic field forming as a result of the current flow through the respective coil 84, 86, 88 then generates in each case one plus pole and one negative pole in the interior 96, which will be discussed below.

The magnetic poles 70, 72, 74, 76, 78, 80 must or should therefore not permanently act as positive pole or negative pole, but rather can be made by energizing the respectively corresponding coil to a positive pole or negative pole. This is particularly so that, if one of these coils 84, 86, 88 is traversed by an electric current, the relevant Coil 84, 86, 88 generates a magnetic field with its associated previously addressed poles 70 and 72, or 74 and 76, or 78 and 80. In the above-mentioned pairwise order, these poles are assigned to the coils 84, 86 and 88. Which of the two respective poles 70 and 72 assigned to a coil 84 or 86 or 88, or 74 and 76, or 78 and 80 is a positive pole and which is a negative pole, depends on the direction in which the relevant coil 84, 86, 88 is traversed by electric current.

It should also be noted that these poles 70, 72, 74, 76, 78, 80 need not be physically tangible, and thus can be formed by the magnetic field itself.

Each of the coil supports 90, 92, 94 may also be made of electrically conductive material, such as metal, in particular copper, or of an electrically insulating material.

It should be noted that instead of a plurality of coil supports 90, 92, 94, a common coil support for several or all coils 84, 86, 88 can be used.

In which of the coils 84, 86, 88 and the bobbins 90, 92, 94 enveloped interior space 96, a linearly displaceable part is arranged, which is also referred to as rotor or drive axle 24, and in the direction of the axis 82 by means of the coils 84, 86th , 88 is axially displaceable. This drive axle 24 is completely or partially designed as a permanent magnet and accordingly forms magnetic poles 100, 102 at its axial ends 104, 106.

The drive shaft 24 may be provided with an eye 26 for coupling to the plunger 16, or be fixedly coupled to an intermediate portion 107, which in turn has the eye 26. Instead of the eye 26, however, a differently designed coupling point for the plunger 16 may be provided.

Axial between the coils 84, 86, 88 and / or coil supports 90, 92, 94 may be provided electrical and / or magnetic insulators 108, 110, however, have radially inwardly through holes 112, so that the rotor 24 can enter or pass unhindered ,

The material forming the coils 84, 86, 88, such as wire, forms end portions 114, 116, 118, 120, 122, 124 which are connected to suitable terminals 126, 128, 130, 132, 134, 136 for electrical connection to one another Voltage source 138 are coupled. Further, a switching device 140 is provided, by means of which optionally one, possibly also simultaneously or temporally overlapping a plurality of the coils 84, 86, 88 is coupled to the electrical voltage source 138 such that the relevant coil 84, 86, 88 of an electric Current is flowing through and the coil 84, 86, 88 associated with these poles 70, 72, 74, 76, 78, 80, ie magnetic plus pole and magnetic negative pole, training or be activated.

Further, a control device 142 is provided which the energization of the coils 84, 86, 88 and / or the switching positions of the switching device 140 to cause the respectively desired axial displacement of the rotor 24, and thus of the plunger 16. This control device 142, which may also have other control functions, such as the control of the workpiece movement by the press, controls the coils 84, 86, 88 in a defined order, so as to effect the respective desired axial displacement of the rotor 24. The driving takes place so that the axial displacement by the respective interaction of the poles 100, 102 of the rotor 24 with the forming poles 70, 72, 74, 76, 78, 80 of the respective energized coil 84, 86, 88, comes about. It is exploited that the same magnetic poles, ie two Magnetic positive poles or two magnetic negative poles, repelled and different poles, ie a positive magnetic pole and a negative magnetic pole, tighten.

By corresponding, in particular also sequentially, controlled energization of the various coils 84, 86, 88 by means of the control device 142, an axial movement of the drive shaft 24, and thus of the plunger 16, can be effected, which extends axially over a plurality of the coils 84, 86, 88 can extend.

By the current intensity, which is adjustable in particular, the strength of the poles 70, 72, 74, 76, 78, 80 can be adjusted, and thus on the drive axle 24, and thus the plunger 16, acting force can be controlled. Accordingly, the drive shaft 24, and thus the plunger 16, can be moved axially, optionally in either one of the two opposite orientations. The drive shaft 24, and thus the plunger 16 with the tool mounted or held thereon, can thus be reciprocated for machining the workpiece. This movement can also be controlled by means of the control device 142 so that it is tuned to the feed of the workpiece and its timing.

It should be noted that the drive shaft 24 can be stopped and held in predetermined axial positions or in any axial position of its axial travel range. For this purpose, for example, be provided that - depending on the desired holding position and / or number of coils 84, 86, 88 - one or more coils 84, 86, 88 are energized such that in the desired position by means of the poles 70th , 72, 74, 76, 78, 80 of the currently energized coils 84, 86, 88 an axial force equilibrium on the drive axle 24 is generated. About the corresponding, in particular then temporally variable, power relationships can also be a damped braking movement of the drive shaft 24 are generated. The corresponding tuning of the current supply in the one or more coils 84, 86, 88 can be controlled by the control device 142.

In particular, a plurality of coils 84, 86, 88 can also be supplied with current at the same time or overlapping in time.

It may further be provided a position sensor for the rotor 24, which determines the axial position of the rotor 24 and transmitted to the control device 142, so that the control device 142 their control functionalities, such as the control of the axial movement of the drive shaft 24, taking into account, in particular momentary , Axialstellung the drive shaft 24 can perform. Alternatively, however, the respective axial position can also be determined by calculation in the control device 142 as a function of previous control characteristics.

It should be noted that a rotation lock for the rotor 24 may be present, which counteracts a rotation of the rotor 24 about the axis 82. While in the Fig. 11 to 13 the bobbin carriers 90, 92, 94 are hollow cylindrical and the rotor 24 are shown cylindrically, but other cross-sectional shapes, such as, for example, triangular, quadrangular, pentagonal, hexagonal or the like may also be provided in each case.

With regard to the number of coils 84, 86, 88 it should also be noted that instead of the three in the Fig. 11 to 13 also shown only two, or more than three, such as four or five or six or seven or more than seven, may be provided.

Claims (15)

Press for generating a pressure force for machining a workpiece with: a press table (10), a press frame (12), - a pestle (16), and at least one drive designed as a linear electric motor (20) for driving the plunger (16),
wherein the at least one linear electric motor (20) has a plurality of mutually offset magnetic poles (70, 72, 74, 76, 78, 80) and a means of these poles (70, 72, 74, 76, 78, 80) linearly displaceable part (24), characterized in that the magnetic poles (70, 72, 74, 76, 78, 80) of at least one linear electric motor (20) comprise coils (84, 86, 88) extending around an axis (82) ) which are axially offset relative to each other with respect to this axis (82), and in that the linearly displaceable part (24) extends in the direction of this axis (82) and by means of the coils (84, 86, 88) in the direction of this axis (82) is linearly displaceable. Press according to claim 1, characterized in that the linearly displaceable part (24) is rotationally symmetrical. Press according to one of the preceding claims, characterized in that the linearly displaceable part (24) is a drive axle. Press according to one of the preceding claims, characterized in that the force transmission path between the linear electric motor (20) and the plunger (16) is free of rotating parts. Press according to one of claims 3 and 4, characterized in that the drive axle (24) is coupled directly to the plunger (16). Press according to one of claims 3 or 4, characterized in that the drive axle (24) via a toggle lever with the plunger (16) is coupled. Press according to one of the preceding claims or according to the preamble of claim 1 and optionally one or more of the characterizing parts of claims 2 to 6, characterized in that the at least one linear electric motor (20) in the press table (10) is integrated. Press according to one of Claims 1 to 6, characterized in that the press has a press head (14) located above the press table (10), between the press table (10) and the press head (14) a working area (62) for the machining of Workpieces is formed, and wherein the at least one linear electric motor (20) in the press head (14) is integrated. Press according to one of the preceding claims, characterized in that the drive axis (24) of the linear electric motor (20) is located parallel to the thrust direction of the plunger (16). Press according to one of claims 1 to 8, characterized in that the drive axis (24) of the linear electric motor (20) perpendicular to the thrust direction of the plunger (16) is located. Press according to one of the preceding claims, characterized in that four linear guides for the plunger (16) are provided. Press according to one of the preceding claims, characterized in that in the direction of the thrust of the plunger (16) located height of said plunger (16) is less than the perpendicular to this thrust extending width of the plunger (16) and / or as the is perpendicular to this thrust direction and perpendicular to the width of the associated width direction extending depth of the plunger (16). Press according to one of the preceding claims, characterized in that on the plunger (16) a first tool receiving area (46) for receiving a first tool is arranged. Press according to one of the preceding claims, characterized in that a second tool receiving area (50) for receiving a second tool is arranged on the press table (10). Press according to one of the preceding claims, characterized in that the press (1) for preventing the breakdown of the plunger (16) in the absence of power supply has a holding brake for the drive axis (24).

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