DE102010012343A1 - Shaping machine i.e. servo press, for forming cold or warm metal workpiece i.e. metal sheet, has eccentric cam axles whose oscillation motion region is spaced along circular path and lower terminal point - Google Patents

Abstract

The machine (1) has eccentric cam axles whose lower terminal point on a circular path corresponds to a lower maximum of a ram stroke movement. An upper terminal point of the eccentric cam axles on the circular path corresponds to an upper maximum of the ram stroke movement, so that a range of rotational movement (RB) of the eccentric cam axles between the terminal points corresponds to a maximum ram stroke of a plunger (7). An oscillation motion region of the eccentric cam axles is spaced along the circular path and the lower terminal point.

Description

The present invention relates to a forming machine for cold or hot forming of metallic workpieces, such as metal sheets, preferably a servo press.

Such forming machines for cold and massive forming of solid metals or sheets are described by way of example in the following documents.

DE 10 2004 009 256 B4 describes a press with a plunger which is movable by a drive means with servomotors back and forth in a working direction, so that the press with reversing the servomotors for performing press strokes is operable. Furthermore, it is described that the eccentrics are synchronized via a transmission branch and at least one servo motor operates position-controlled.

DE 91 05 001 U1 describes a press drive with transverse shafts for elongated ram, with gear transmission, characterized in that in a filled with gear oil gearbox, the two transverse waves, a drive shaft and an intermediate shaft, all interlocked via two equal sized, rotatable on the waves and lockable gears with balancing weights for Mass balance 1st order, between which the shaft bearing points in the two chamber walls and a balancing mass for mass balance 1st order are provided. Here, an elongated plunger is hinged to two connecting rods.

From the literature ( Dubbel, Paperback for Mechanical Engineering, 21st Edition 2004, T65 / 4.2.3 ) it is known that the total stroke in eccentric presses usually in the range H _max / H _min = 10 is adjustable. The stroke adjustment changes the course and magnitude of the ram force, ie the force that is made available by the machine at any time during the pressing process, as well as the ram speed.

The object of the invention is now to provide a cold or hot forming of metallic workpieces, such as metal sheets, suitable forming machine with a simple and effective stroke adjustment available.

This object is achieved by a forming machine with the features of claim 1. Advantageous embodiments and modifications of the invention will become apparent from the dependent claims.

The forming machine according to claim 1 is suitable for cold or hot forming of metallic workpieces, such as metal sheets, and preferably also determined and preferably formed as a servo press and includes at least a first, preferably provided on a machine table, tool receiving area (or: tool carrier, tool holder) for at least one first, in particular lower, forming tool and at least one second, on a plunger (or: driven support member) provided second tool receiving area for at least a second, in particular upper, forming tool. The plunger is arranged movable by means of a drive device against the first tool receiving area. This drive device for the plunger has at least one, in particular two, preferably four, connecting rods and at least one crankshaft rotatable about a shaft axis, preferably two crankshafts rotatable about a shaft axis. The one or more connecting rods is or are in a first, in particular upper, connecting rod indirectly (eg., Via an intermediate part or a conversion device) or coupled directly to the plunger, and at the at least one crankshaft or an associated one of the crankshafts in one second, in particular lower, connecting rod bearing is coupled. Each crankshaft has an eccentric for each associated connecting rod, preferably two associated connecting rods on which, forming the second connecting rod bearing, a, in particular lower, connecting rod end (or: connecting rod eye) of the connecting rod is mounted eccentrically to the shaft axis of the crankshaft.

Upon rotation of the crankshaft about its shaft axis an eccentric axis of the eccentric is now moved or moved in a rotational movement along a circular path about the shaft axis and the plunger follows this rotational movement of the eccentric axis due to the coupling with the crankshaft over the one or more connecting rods in a plunger stroke to the first Tool receiving area towards or away. In this case, a first, preferably lower, end point (or: dead center) of the eccentric axis on the circular path corresponds to a maximum lower dead center of the ram stroke movement. The maximum bottom dead center may be defined such that there the first tool receiving area and the second tool receiving area come or would come closest to each other (or the minimum possible distance) (or: the ram experiences its maximum deflection towards the first tool receiving area). Furthermore, a second, preferably upper, end point of the eccentric axis on the circular path corresponds to a maximum upper dead center of the ram stroke movement, which maximum upper dead center can be defined so that there the first tool receiving area and the second tool receiving area furthest away from each other (at the maximum possible distance) are or (or: the ram experiences its maximum deflection away from the first tool receiving area). The range of rotational movement or circular path of the eccentric axis between the first end point and the second end point thus corresponds to a maximum or maximum possible with the connecting rod Stößelhubweg (or short: ram stroke) of the plunger.

However, the rotational movement of the eccentric axis about the shaft axis is now not a full rotation about the shaft axis, but limited to a pendulum motion range between two reversal points (or: Reversierpunkten) on the circular path, corresponding to a pendulum angle interval between two end angles with an angular distance less than 360 ° or 2π. At the reversal points, the eccentric axis reverses (after previous deceleration) in the direction of rotation and is accelerated again in the opposite direction of rotation (similar to a circular pendulum).

According to the invention, the pendulum motion range (or pendulum angle range) of the eccentric axis is now set or adjusted such that the pendulum motion range is spaced from the first, preferably lower, end point along the circular path, in particular at a distance angle, and / or the pendulum motion range is the first, preferably lower, end point not included. The first, preferably lower, end point on the circular path for the rotational movement of the eccentric axis is thus outside of the oscillating range and is not traversed by the eccentric axis.

By this, in particular "off-center" determination of the pendulum motion range is, in contrast to the prior art, not reached by the plunger, the maximum lower dead center and thus the maximum ram stroke, but only one by the position of the first end point of the eccentric axis closest reversal point fixed set lower dead center, in which then have the two tool receiving areas over the minimum possible, achieved at the first end point of the eccentric axis distance.

According to the invention can now be varied and adjusted to a desired position by setting or fixing the position of the reversal points of the oscillating range on the circular path of the lower dead center of the ram stroke movement. Thus, the stroke (the stroke length or the stroke) or the deflection of the plunger can be selectively changed and adjusted for its Stößelhubbewegung.

In a preferred embodiment, the pendulum movement region, in particular within a semicircle, is arranged on the circular path between the first end point and the second end point, ie. H. also the second end point is not within the range of oscillation.

By defining the pendulum movement range and its reversal points according to the invention, in particular the load or forming force can be adjusted and adjusted during forming to a value which can be set within wide limits below the maximum possible forming force of the forming machine acting at the maximum lower dead center of the plunger. In particular, since the lower track points of the eccentric axes are not identical with the lower points of the full rotational movement, the maximum available plunger force is reduced. This may be desirable, for example, in applications that require less forming force. If the upper points of the eccentric axes are not identical with the upper points of the full rotational movement, the plunger does not move to a fully open position. This may be desirable to achieve high clock rates.

Preferably, the distance angle of the pendulum movement range from the first end point is at least 5 °, in particular at least 12 °.

The distance angle of the pendulum movement range from the second end point may be at least 15 °, in particular at least 45 °. In particular, the pendulum motion range is in a range between 85 ° and 175 ° relative to the second end point.

In a preferred embodiment, the forming machine comprises at least one position sensor for measuring the position of the eccentric axis on the circular path or a clearly correlated with the position of the eccentric axis on the circular path size, z. B. the position of the crankshaft, and for outputting a unique measure of the position of the eccentric axis forming measuring signal or measured value at a sensor output. Preferably, a position sensor is provided on at least one crankshaft and / or on at least one transmission gear, on at least one bearing of a crankshaft and / or on at least one eccentric, by which determines the angular position of the crankshaft and / or the transmission gear and / or the at least one eccentric becomes. The determination of the angular position of the crankshaft allows an immediate conclusion to the vertical position of the connecting rod and the plunger. Thereby, the actual value of the plunger position can be detected in a simple manner.

Furthermore, at least one control device is preferably provided, which, depending on the measurement signals or measured values of the at least one position sensor and taking into account stored (fixed) signals or values, drives the drive device for the plunger such that the rotational movement of the eccentric axis of the eccentric is limited about the shaft axis of the crankshaft to the predetermined or desired oscillating range between the two reversal points on the circular path. This occurs in particular in that the measurement signals or measured values of the at least one position sensor lie or remain in an interval limited by the stored signals or values corresponding to the reversal points and / or that the eccentric axis reverses its direction of movement along the circular path at the reversal points and thus a pendulum movement or oscillating motion occurs. The control direction can be realized in particular with a processor with associated memory, a personal computer or a specific electronic control.

In this embodiment, the operator therefore has the option of entering desired reversal points of the eccentric axis (s) directly, for example via a user interface such as a simple input panel with display, for example via corresponding angle values or also corresponding position values or length values for the lower dead center and the upper dead center of the plunger, and so set a desired pendulum motion range and thus a desired ram stroke.

The variation of the reversal points also allows adaptation of the forming machine to different feeders by adjusting the position and / or height of the pendulum stroke range. Also can be increased by, for example, a smaller travel of the ram, the clock rate of the forming machine.

The motion profile or the dependence of the angular position of the eccentric axis on the time can be controlled in a variety of ways. A movement that is at least similar to a harmonic oscillator is preferred.

It can also be provided for the forming machine, a characteristic that represents the ram force depending on or at the associated first endpoints. The operator thus has an easy way to set the machine according to the desired forming force.

The interaction of the arranged below the machine table servo motor and the limitation of the vertical mobility of the plunger, the risk of kinking of the connecting rod is prevented and the load of the plunger can be adapted to machine and process requirements. Since in such forming machines the ram force is dependent on the ram travel, the operating point of the forming machine can be set optimally as a function of further process parameters by such a determination of the pendulum stroke range.

The invention will now be explained in more detail by means of embodiments, reference being made to the accompanying drawings. Show it:

1 a forming machine according to the invention in a representation from the front, wherein relevant components are partially cut free and thus visible,

2 the forming machine according to 1 in a partially sectioned view from the side

3 a pendulum stroke range according to the prior art,

4 a pendulum stroke range according to the invention,

5 a force-displacement diagram of a forming machine with a Pendelhubbereich according to the prior art and

6 a force-displacement diagram of a forming machine with a Pendelhubbereich according to the invention.

Corresponding parts and sizes are in the 1 to 6 provided with the same reference numerals.

The 1 to 3 show a, in particular designed as a servo press, forming machine 1 holding a machine table 2 , one or two stands 4 with a crosshead 5 and one on the stand (s) 4 and / or crosshead 5 guided, vertically movable plunger 7 includes.

At one the pestle 7 facing top of the machine table 2 , in particular on a table top, is a tool holder 3 for receiving, not shown, lower forming tools provided. At the machine table 2 facing bottom of the ram 7 is a tool holder 70 provided for receiving, not shown, upper forming tools. The tool holders 3 and 70 For example, in a conventional manner, a grid from mounting positions for positioning the tools. The area between the tool holders 3 and 70 from machine table 2 and pestles 7 forms the workspace 6 in which the tools and then between the tools the workpieces are (can) be arranged. During the forming process in particular pressing process at a servo press, the plunger is 7 moved down so that upper and lower forming tools or tool halves by means of the plunger 7 applied forming force, in particular pressing force, cooperate and reshaping a workpiece located between the forming tools according to the geometric and mechanical engineering design of the tools. The to the machine table 2 towards vertical downward working direction or forming direction of the plunger 7 is shown with an arrow marked P and is the pressing direction in a servo press.

At the crosshead 5 and / or the stand (s) 4 are now, preferably four, vertical guides, in particular guide rails and / or guide grooves, arranged and fixed, of which two front guides 45 and 46 on both sides in 1 are shown. The pestle 7 has corresponding guide elements in particular also four guide elements, on, on or in the guides on the stand (s) 4 and / or crosshead 5 , in particular via intermediate rolling bearings, are guided vertically. In 1 The two front guide elements are shown in or on the guide 45 Guided guide element shown on the right 75 and that in or on the lead 46 guided guide element shown on the left 76 ,

The pestle 7 is in the preferred embodiment shown on a console 9 held with the pestle 7 is moved along and also about, preferably also four, guide elements on the vertical guides, in particular via intermediate rolling bearings, is guided, of which in 1 the two front guide elements 95 at the lead 45 and 96 at the lead 46 are shown. The console 9 forms a cross-sectionally approximately U-shaped, the plunger 7 from above and from the side framing or surrounding draw frame with two vertically extending side panels 91 and 92 , the side of the plunger 7 surround or frame, and one the two side panels 91 and 92 connecting horizontal cross member 93 on which the plunger 7 via connecting elements (adjusting devices) 8th is attached hanging and thus above the plunger 7 is arranged. console 9 and pestles 7 are firmly connected together during the forming movement and are moved together under common linear vertical guidance in the guides, z. B. 45 and 46 , on stand 4 and / or crosshead 5 ,

For the forming movement of the ram 7 relative to the machine table 2 is the pestle 7 of at least two, in the illustrated embodiment four, connecting rods 11 to 14 vertically against the machine table 2 movable. The connecting rods 11 to 14 are with the side panels 91 and 92 the console 9 , preferably in the corner regions, coupled to the front and back of the side part 91 the two connecting rods 11 and 14 and on the front and back of the side panel 92 the connecting rods 12 and 13 , The four connecting rods 11 to 14 thus pull the console 9 in the forming movement down to the machine table 2 and press the console 9 in the return movement back up. The console 9 pushes with her crosspiece 93 via the connecting elements ( 8th ) during the forming movement of the plunger 7 down and pull the plunger 7 in the return movement with upwards. It takes the guided console 9 even as Zugrahmen the tensile forces and possibly occurring tilting moments on and the plunger 7 can be largely free of transverse forces and torque-free in its linear guide on stand 4 and / or crosshead 5 move.

In the illustrated embodiment is at an upper connecting rod end 11A to 14A every connecting rod 11 to 14 one at the associated side part 91 and 92 bolt fastened to the console along a bolt axis passing through the bolt through or into an opening (the upper "eye") in the upper end of the connecting rod 11A to 14A plugged and stored rotatably therein. You can see them in the 1 and 2 bolts 61 . 62 and 64 with the associated bolt axes B1, B2 and B4 in the associated connecting rod ends 11A . 12A and 14A ,

The two a side part 91 or 92 the console 9 assigned and at their upper connecting rod ends 11A to 14A coupled with connecting rod 11 and 14 respectively. 12 and 13 are at their lower ends 11B and 14B respectively. 12B and 13B with each other via one crankshaft (or: eccentric shaft) 15 respectively. 16 coupled. The two connecting rods 11 and 14 at one, in 1 and 3 Left, side are through a first crankshaft 15 connected to each other, which is rotatable about a shaft axis A1, and the two connecting rods 12 and 13 on the other side are through a second crankshaft 16 connected to each other, which is rotatable about a shaft axis A2. The two shaft axes A1 and A2 of the crankshafts 15 and 16 are arranged parallel to one another and in particular at the same height or in the same horizontal plane.

The crankshafts 15 and 16 point for each connecting rod 11 to 14 one associated with the crankshaft 15 or 16 co-rotating eccentric element 31 to 34 on with an eccentric axis, which is arranged parallel to and spaced from the respective shaft axis A and B, respectively. You can see it in 1 the eccentric axes E1 and E2 of the eccentric elements 31 and 32 and in 2 the eccentric axes E1 and E4 of the eccentric elements 31 and 34 ,

Each eccentric element 31 to 34 is on the crankshaft 15 or 16 formed in the form of an arm or projection and includes a pin or bolt passing through an opening (the "eye") in the lower end of the connecting rod 11B to 14B of the associated connecting rod 11 to 14 inserted and rotatably mounted therein. The eccentric axes, in particular E1, E2 and E4 extend through the pins or bolts of the eccentric elements, in particular 31 . 32 and 34 ,

Upon rotation of the crankshaft 15 respectively. 16 the eccentric elements rotate 31 to 34 with and their eccentric axes, z. B. E1, E2 and E4, move in a rotational movement (eccentric motion) RB along a circular path KB about the shaft axis A and B, wherein the diameter D of this rotational movement RB twice the distance from the eccentric axis, in particular E1, E2 or E4, to Shaft axis A or B corresponds.

The bolt axes, in particular B1, B2 and B4, the bolt, in particular 61 . 62 and 64 , in the upper connecting rod ends 11A to 14A and the eccentric axes, in particular E1, E2 and E4, the eccentric elements, in particular 31 . 32 and 34 , Preferably, parallel to each other and preferably also parallel to the shaft axes A1 and A2 of the crankshafts 15 and 16 ,

The bolts on the side panels 91 and 92 form together with the upper connecting rod ends 11A to 14A and their openings or eyes each upper rod bearing for coupling the connecting rod 11 to 14 to the console 9 and thus to the pestle 7 , The eccentric elements, for. B. 31 . 32 and 34 , in particular their bolts, in turn form together with the lower connecting rod ends 11B to 14B and their openings or eyes each lower connecting rod bearings, which are used for coupling the crankshaft 15 or 16 and thus the servomotors 21 to 24 to the associated connecting rods 11 to 14 are provided. However, the upper and lower connecting rod bearings can also be designed in other known manner.

The crankshaft rotating about the shaft axis A1 15 is from two synchronized servomotors 21 and 24 driven and rotating about the shaft axis A2 crankshaft 16 is also from two synchronized servomotors 22 and 23 driven, the two servomotors 21 and 24 respectively. 22 and 23 preferably in each case in the region of the shaft ends to the crankshaft 15 or 16 are coupled. The two servomotors per crankshaft also serve to avoid torsional moments in the crankshaft as possible or to keep small.

In the illustrated embodiment (see especially 3 ) is between each servomotor 21 to 24 and associated crankshaft 15 or 16 a transmission gear 51 to 54 switched to translate the engine speed to the crankshaft speed, in particular a gear transmission.

But it is also a direct drive of the crankshafts by the servomotors (in which case the engine speed corresponds to the crankshaft speed) without intermediate gears possible, especially when using torque motors or segment motors. Furthermore, only one servomotor can also be provided per crankshaft.

The four connecting rods 11 to 14 are preferably identical to each other, in particular the same length. Preferably, the two drive units, each of the side parts 91 and 92 are assigned to the console and two connecting rods 11 and 14 respectively. 12 and 13 with associated connecting rod bearings, a crankshaft 15 respectively. 16 and two associated servomotors 21 and 24 respectively. 22 and 23 if necessary with gearboxes 51 and 54 respectively. 52 and 53 comprise, structurally identical to each other and arranged with respect to a central plane of symmetry S mirror-symmetrical. Likewise, each is also the console 9 and the pestle 7 and possibly also stands 4 and crosshead 5 as well as the machine table 2 preferably formed mirror-symmetrically to the plane of symmetry S.

The servomotors 21 to 24 and the associated gears 51 to 54 are on the outer longitudinal sides of the machine table 2 arranged below the tool holder 3 , Also the crankshafts 15 and 16 and the lower connecting rod bearings and lower portions of the connecting rods 11 to 14 are below the lower tool holder 3 of the machine table 2 and thus also below the plunger 7 intended. The upper connecting rod bearings of the connecting rods 11 to 14 are on the other hand above the tool holder 3 of the machine table 2 , in particular at the height of the plunger 7 arranged. This is achieved in an advantageous manner that of the machine table 2 seen from the above located plunger 7 via its console 9 is pulled down during the forming movement and pressure forces are avoided.

As in 2 pictured, every crankshaft is here 15 in two outer camps 18 and two inner camps 17 rotating in or at the machine table 2 stored. In particular, the crankshaft 15 be constructed in two or more parts except a one-piece design, for example according to 2 two crankshaft parts 15A and 15B which have a coupling 19 connected to each other.

Further, for detecting the servomotor and thus the plunger 7 and preventing one unwanted startup on each servomotor 21 to 24 or on the crankshaft 15 and 16 Also, an unspecified mechanical brake or locking unit may be arranged.

As already described above, the lower and upper forming tools on the respective tool holders 3 respectively. 70 mounted, wherein the vertical distance is slightly greater than the maximum vertical deflection or the stroke of the plunger 7 between OT and UT corresponding to the Pleuelhub D to allow a reshaping of lying between the forming tools workpiece, in particular sheet metal.

The drive of the crankshafts 15 and 16 over the servomotors 21 to 24 and is about the control device 20 synchronized fully electronically, so that, for example, the servomotors approach coordinated and run and / or provide matched torques available.

A rotary motion of the crankshaft 15 or 16 about their shaft axis A1 or A2 now leads to an eccentric movement or rotational movement RB of the two attached to the crankshaft eccentric elements 31 . 32 or 34 , The associated connecting rods 11 and 14 respectively. 12 and 13 follow this rotational movement RB of the eccentric elements at their lower connecting rod ends 11B and 14B respectively. 12B and 13B , wherein the upper end of the connecting rod 11A to 14A same connecting rod 11 to 14 essentially moved vertically up and down between two axial end positions.

The angular positions of the eccentric elements, z. B. 31 . 32 and 34 , different connecting rods 11 to 14 are generally set equal and synchronized with each other. Due to the synchronized eccentric rotation movements RB, all connecting rods move 11 to 14 at their upper connecting rod ends 11A to 14A vertically in a vertical movement designated VB linearly and synchronously up or down and thus move the console coupled to the four upper connecting rod bearings 9 and the plunger connected thereto 7 linear in the forming direction P down and then again opposite to it upwards.

In 1 are the lower point of rotation RB as UP1 at the connecting rod 11 and UP2 at the connecting rod 12 drawn and the corresponding upper point as OP1 at the connecting rod 11 and OP2 at the connecting rod 12 , At complete rotation or complete rotation of the crankshaft through the upper point and lower point, so z. B. OP1 to UP1 or OP2 to UP2, the maximum possible Pleuelhub would be reached, which then corresponds to the full diameter D of the circle or circular path KB of the eccentric or rotational movement RB. In this case, then the ram stroke between the maximum upper dead center OT _max and the maximum lower dead center UT _max equal to the maximum Pleuelhub D and the maximum ram stroke H _max .

However, according to the invention, the eccentric or rotational movement RB takes place only in a pendulum movement about a center point P ₀ as rotational movement RB limited to a pendulum angle range with a periodically changing or alternating direction of rotation.

3 and 4 show now schematic diagrams of two different oscillations of a about a shaft axis A rotating or oscillating E eccentric axis within a pendulum angle interval 2Δφ <360 ° between two reversal points P1 and P2. These two pendulum movements are respectively as a special case of the rotational movements RB of the eccentric axis E1 about the shaft axis A1 or the eccentric axis E2 about the shaft axis A2 in the forming machine according to 1 and 2 can be used, in each case instead of a full circumferential movement. A complete circulation of the eccentric is thus avoided, but the eccentric and its eccentric axis E oscillates under direction reversal of the rotational movement RB between the two reversal points P1 and P2 along a circular segment back and forth.

3 shows a known eccentric pendulum motion according to the prior art, 4 however, shows a pendulum movement of the eccentric according to the invention.

In the known per se from the prior art pendulum movement 3 the eccentric axis E oscillates about a shaft axis A between within a circle segment or pendulum angle interval from -Δφ to + Δφ by a central angle φ ₀ . This central angle φ ₀ corresponds to a center point P ₀ on the circular path KB, while the in 3 left end angle φ ₀ - Δφ a first reversal point P _{1 of} the oscillating motion of the eccentric axis E on the circular path KB and the in 3 right end angle φ ₀ + Δφ a second reversal point P ₂ corresponds to this pendulum motion. At the reversal points P ₁ and P ₂ , the eccentric axis E comes to a standstill and is then accelerated in the direction of movement reversal in the respective opposite direction until the other reversal point is reached again and the process begins again. The state of the art is now, as in 3 to recognize the center P _{0 of} the pendulum motion, which lies halfway between the reversal points P ₁ and P ₂ , identical to the lower end point UP of the eccentric axis E. The center angle φ ₀ , the pendulum motion is correspondingly identical to the lower angle φ _U.

In the example of 3 Thus, φ _{0 is} at 180 ° relative to the upper end point OP, and Δφ = 45 °, ie the pendulum angle interval is between 135 ° and 225 ° relative to OP.

The lower end point UP on the circular path KB and the associated lower angle φ _U are defined as the point or angle of the eccentric axis E of the eccentric (and thus the lower connecting rod bearing of the associated connecting rod), in which the plunger 7 reaches its lower reversal point or maximum lower dead center UT _max its ram stroke movement, so the plunger the lower tool receiving area 3 next comes or the pestle 7 its maximum deflection towards the machine table 3 or downwardly experiences, or, in another view, in which the relatively moving forming tools have the least distance from each other. In the lowest position of the eccentric axis E at the center P ₀ = UP or at the center angle φ ₀ = φ _U is generally the connecting rod 11 in an exactly vertical position or in an orthogonal position relative to a horizontal plane.

The upper end point OP is defined as the point of the eccentric axis E of the eccentric on the circular path KB (and thus the lower connecting rod bearing of the associated connecting rod), in which the plunger 7 reaches its upper reversal point or maximum upper dead center OT _{max of} its ram stroke movement, ie the ram 7 from the lower tool receiving area 3 farthest away or its maximum deflection towards the machine table 3 experiences away, or, in another view, in which the relatively moving forming tools have the greatest distance from each other. Also in this uppermost position of the eccentric axis E at the upper end point OP is generally the connecting rod 11 in an exactly vertical position or in an orthogonal position relative to a horizontal plane.

This oscillation about the lower end point UP according to the prior art, illustrated by means of 3 , has the great advantage that the maximum possible ram or pressing force is available and the tools are optimally closed.

5 shows to illustrate the force a diagram of a pendulum motion according to 3 according to the prior art for a weggebundene pressing machine and shows the relevant parameters. The course of the ram force F _St is shown as a function of the ram stroke h, as well as the forming force F as a function of the ram stroke h and the nominal force F _N. It can be seen that the forming force F and the ram force F _St at the bottom dead center UT _{max of} the plunger, the center P ₀ = UP or the center angle φ ₀ = φ _{U of} the eccentric axis E of the connecting rod according to 3 corresponds to reach a maximum.

4 now shows a schematic diagram of a pendulum motion of the eccentric axis E of a connecting rod about the shaft axis A according to the invention. Unlike in 3 according to the invention, the center angle φ _{0 of} the pendulum angle interval is offset or shifted by an offset angle α relative to the lower angle φ _U , ie φ ₀ = φ _U + α. In the example of 4 the offset occurs counterclockwise, but can also be done in the same clockwise direction. The offset angle α is greater than half the pendulum interval length Δφ that is α - Δφ> 0. Thus comprises the pendulum angle interval between the two end angles φ ₀ - Δφ = φ _U + α - Δφ on the one hand and φ ₀ + Δφ = φ _U + α + Δφ on the other not the lower angle φ _U. In other words, the circular path section of the circular path KB between the first reversal point P _{1 of} the oscillating motion of the eccentric axis E on the circular path KB at the end angle φ ₀ - Δφ and the other reversal point P ₂ at the end angle φ ₀ + Δφ does not include the lower end point UP at the bottom Angle φ _U , in contrast to the prior art. The pendulum motion thus takes place asymmetrically to the lower end point UP under its exclusion.

The lower end point UP is therefore not traversed by the eccentric axis E and thus the plunger 7 not maximally in the direction of the machine table 2 deflected, so does not reach its maximum lower dead center UT _max , but only a lower dead center UT> UT _max , which is less far from OT _max than UT _max (ie OT _max - UT <OT _max - UT _max ) and the first Reversing point P ₁ corresponds to the pendulum motion. By the respective determination of the first reversal point P ₁ , the plunger or pressing force can be adjusted or varied and can also be set lower forming forces. The at the tool holders 3 and 70 arranged tools must now be set so that the tools are closed when the eccentric axis E reaches the first turning point P ₁ .

Also, the second reversal point P ₂ is preferably not at the upper end point OP of the circular path KB, but below, so that the upper dead center OT of the plunger 7 at this second reversal point P _{2 is} also smaller than OT _max . This is achieved by choosing α + Δφ <180 ° (or π) or, correspondingly, φ ₀ + Δφ <φ _U + 180 °, as in 4 to recognize.

Advantageous values for the offset angle α between φ ₀ and φ _U are between 30 ° and 60 ° and for half the pendulum interval length Δφ between 25 ° and 55 °. In the example of 4 is α = 50 °, that is φ ₀ based on OP at 130 °, and Δφ = 45 °, ie the pendulum angle interval is based on OP between 85 ° and 175 °.

6 shows to illustrate the forces acting a force-displacement diagram to a pendulum movement according to the invention as in 4 shown. Plotted are again the ram force F _St and the forming force F and the nominal force F _N over the ram stroke h. The pendulum motion of the eccentric axis E of the connecting rod between the reversal points P ₂ and P ₁ is shown and corresponds to the associated ram stroke between the top dead center OT and the bottom dead center UT of the plunger. At the reversal point P ₁ corresponding to the lower dead center UT of the ram stroke h, the maximum applied forming force F _{max is} reached, which is less than the maximum forming force that would be achieved at UT _max . This makes it possible to operate a forming machine according to the invention so that a lower forming force than the forming force occurring at maximum ram stroke H _max is achieved. This considerably increases the variability of the forming machine with regard to its forming energy and forming force.

In order to set the reversal points P ₁ and P ₂ , the servo motors are driven or operated accordingly in the present embodiment. Preferably, the position of the eccentric axes is determined metrologically, for example by means of, as in 2 to see, on the crankshafts 15 and 16 provided position sensors 97 over which the rotational position or the angular position of the crankshaft 15 . 16 and thus also the eccentric axes is detected. Preferably, position sensors 97 arranged so that the angular positions of each eccentric element 31 . 32 and 34 can be detected. Alternatively or additionally, position sensors 97 at the eccentrics 31 . 32 . 34 itself or on the axles of the transmission gear 51 to 54 be provided.

The position sensors can, for. B. rotary potentiometers or magnetic tilt sensors. In a forming machine 1 with four connecting rods 11 to 14 are preferably four position sensors 97 at the four eccentrics 31 to 34 intended. With the measured values for the positions of the eccentric axes, the servomotors are now controlled so that the pendulum motion range of the eccentric axes is exactly in the predetermined range between the two reversal points P ₁ and P ₂ , ie slowed down before the reversal points and at the reversal points then in their Reverse direction. Alternatively, the position sensors may also be provided on the servomotors themselves and detect their rotational position or number of revolutions in absolute or incremental terms as an unambiguous measure of the position of the eccentric axes or with this uniquely correlated variable.

LIST OF REFERENCE NUMBERS

1

forming machine

2

machine table

3

tool holder

4

stand

5

crosshead

6

Workspace

7

tappet

9

console

11 to 14

pleuel

11A to 14A

upper end of the connecting rod

11B to 14B

lower end of the connecting rod

15, 16

crankshaft

15A, 15B

crankshaft part

17

Bottom Bracket

18

external storage

19

clutch

20

control device

21 to 24

servomotor

25

input unit

31, 32, 34

eccentric

45, 46

guide

51 to 54

up gear

61, 62, 64

bolt

70

tool holder

75, 76

guide element

91, 92

side panel

93

cross section

95, 96

guide element

97, 98

position sensor

d

distance

A, A1, A2

shaft axis

B1, B2

 pin axis

e

eccentric

E1, E2, E4

 eccentric

P

pressing direction

P ₀

Focus

P ₁ , P ₂

 turning point

RB

rotational motion

VB

vertical movement

H

stroke

OT

top dead center of the pestle

UT

Lower dead center of the pestle

S

plane of symmetry

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102004009256 B4 [0003]
• DE 9105001 U1 [0004]

Cited non-patent literature

• Dubbel, Paperback for Mechanical Engineering, 21st Edition 2004, T65 / 4.2.3 [0005]

Claims (7)

Forming machine for cold or hot forming of metallic workpieces, for example metallic sheets, preferably servo press, comprising a) at least one first, preferably on a machine table ( 2 ), tool receiving area ( 3 ) for at least a first, in particular lower, forming tool and at least one second, on a plunger ( 7 ) provided second tool receiving area ( 70 ) for at least one second, in particular upper, forming tool, b) wherein the plunger ( 7 ) by means of a drive device against the first tool receiving area ( 3 ) is arranged movable, c) wherein the drive means for the plunger ( 7 ) c1) at least one, in particular two, preferably four, connecting rods ( 11 to 14 ), which in a first, in particular upper, connecting rod bearing ( 11A to 14A . 61 . 62 and 63 ) directly or indirectly to the plunger ( 7 ), and c2) at least one crankshaft rotatable about a shaft axis, preferably two crankshafts rotatable about a shaft axis (A1, A2) ( 15 . 16 ), at the at least one connecting rod ( 11 to 14 ), preferably two connecting rods ( 11 and 14 . 12 and 13 ), in a second, in particular lower, connecting rod bearing ( 11B to 14B and 31 to 34 ), d) each crankshaft ( 15 . 16 ) for each associated connecting rod an eccentric ( 31 . 32 . 34 ), on which, forming the second connecting rod bearing, a, in particular lower, end of the connecting rod ( 11B to 14B ) of the connecting rod ( 11 to 14 ) eccentric to the shaft axis (A1, A2) of the crankshaft ( 15 . 16 e) wherein rotation of the crankshaft about its shaft axis an eccentric axis (E) of the eccentric in a rotational movement (RB) along a circular path (KB) about the shaft axis (A) is movable or is moved and wherein the plunger ( 7 ) depending on this rotational movement of the eccentric axis (E) as a result of the coupling with the crankshaft via the one or more connecting rods a Stößelhubbewegung to the first tool receiving area ( 3 f) with a first, preferably lower, end point (UP) of the eccentric axis (E) on the circular path (KB) corresponds to a maximum lower dead center (UT _max ) of the ram stroke movement, and wherein a second, preferably upper, end point (OP) of the eccentric axis (E) on the circular path (KB) corresponds to a maximum upper dead center (TDC _max ) of the ram stroke, so that the range of rotational movement or orbit of the eccentric axis between the first end point (UP) and second end point (OP ) a maximum ram stroke (H _max ) of the ram ( 7 ), wherein the rotational movement (RB) of the eccentric axis (E) about the shaft axis to a pendulum motion range between two reversal points (P ₁ , P ₂ ) on the circular path (KB) is limited, h) wherein the oscillating range of the eccentric axis (E ) is spaced from the first, preferably lower, end point (UP) along the circular path (KB) and / or does not include the first, preferably lower, end point (UP). Forming machine according to claim 1, wherein the oscillating range, in particular within a semicircle, between the first end point (UP) and the second end point (OP) on the circular path (KB). Forming machine according to claim 1 or claim 2, wherein the pendulum movement region by a distance angle (α - Δφ) of at least 5 °, in particular at least 12 °, from the first end point (UP) is spaced and / or by a distance angle of at least 15 °, in particular at least 45 °, from the second end point (UP) is spaced and / or based on the second end point (OP) between 85 ° and 175 °. Forming machine according to one of the preceding claims a) with at least one position sensor ( 97 ) for measuring the position of the eccentric axis (E) on the circular path (KB) or a magnitude uniquely correlated with the position of the eccentric axis (E) on the circular path (KB) and for outputting a measurement signal forming a definite measure of the position of the eccentric axis or Measured value and b) with at least one control device ( 20 ), which depends on the measuring signals or measured values of the at least one position sensor ( 97 ) and taking into account stored, the reversal points (P ₁ , P ₂ ) corresponding signals or values, the drive means for the plunger so controls that the rotational movement (RB) of the eccentric axis (E) of the eccentric about the shaft axis of the crankshaft to the predetermined or desired oscillation range between the two reversal points (P ₁ , P ₂ ) on the circular path (KB) is limited, in particular such that the measurement signals or measured values of the at least one position sensor ( 97 ) lie or remain in one of the stored fixed signals or values corresponding to the reversal points (P ₁ , P ₂ ), and / or such that the eccentric axis (E) at the reversal points (P ₁ , P ₂ ) their direction of movement reversed along the circular path (KB). Forming machine according to claim 4, wherein at least one position sensor ( 97 ) on at least one crankshaft ( 15 . 16 ) and / or at least one transmission gear ( 51 to 54 ), at least one warehouse ( 17 . 18 ) a crankshaft ( 15 . 16 ) and / or at least one eccentric ( 31 to 34 ) is provided and / or an angular position of at least one crankshaft ( 15 . 16 ) and / or at least one transmission gear ( 51 to 54 ) and / or at least one eccentric ( 31 to 34 ) measures. Forming machine according to claim 4 or claim 5, wherein the position sensor is a rotary potentiometer or a magnetic tilt sensor. Forming machine according to one of the preceding claims with at least one or any combination of several of the following features: - at least one servomotor ( 21 to 24 ) for driving the at least one crankshaft ( 15 . 16 ), - the pestle ( 7 ) is above the first tool receiving area ( 3 ) or machine table ( 2 ), - each crankshaft ( 15 . 16 ) and the lower connecting rod bearings ( 11B to 14B and 31 to 34 ) the connecting rod ( 11 to 14 ) are below the plunger ( 7 ) and / or below the first tool receiving area ( 3 ) and the upper connecting rod bearings ( 11A to 14A . 61 . 62 and 63 ) the connecting rod ( 11 to 14 ) are above the first tool receiving area ( 3 ) and / or above the second tool receiving area ( 70 ), - each crankshaft ( 15 . 16 ) is in or on the machine table ( 2 ) below the first tool receiving area ( 3 ), in particular in two inner bearings ( 17 ) and two outer bearings ( 18 ), - at least one crankshaft ( 15 . 16 ) is composed of at least two crankshaft parts ( 15A . 15B ), which via a coupling ( 19 ), - each crankshaft ( 15 . 16 ) is equipped with two connecting rods ( 11 and 14 . 12 and 13 ), - each crankshaft ( 15 . 16 ) is powered by two servomotors ( 21 and 24 . 22 and 23 ), in particular at their shaft end regions, wherein in particular the lower connecting rod bearing or the eccentric or on the crankshaft for the one or more connecting rods between the coupling regions of the crankshaft for the servomotors is or are - the at least one servomotor or the two servomotors drives or ., drive the associated crankshaft directly, in particular at the same speed, or via a transmission gear ( 51 to 54 ), - the at least one servomotor ( 21 to 24 ) is below the plunger ( 7 ) and / or below the first tool receiving area ( 3 ) arranged.

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