DE102010060627A1 - Forming machine, particularly for cold and hot forming of metal workpieces, such as metal sheets, comprises machine table, which has tool receiving area for lower forming tool and plunger with tool receiving portion - Google Patents

Abstract

The forming machine (1) comprises a machine table (2), which has a tool receiving area (3) for a lower forming tool and a plunger (7) with a tool receiving portion (70) for an upper forming tool. The plunger is arranged above the machine table and is movably arranged by a drive unit, particularly by a servo motor against the machine table.

Description

The present invention relates to a forming machine with ram control, in particular for cold and hot forming of solid metals or sheets.

Such forming machine for cold and massive forming of solid metals or sheets are known and are described in various documents mentioned here.

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 reversal of the servomotors for performing press strokes is operable. A control device is described which controls a servo motor in position-controlled manner. This is this with a position sensor, z. B. an angle sensor, connected, which precisely detects the rotation angle of the eccentric and transmits corresponding signals to the control device. This contains a module for specifying a path-time curve of the plunger or corresponding rotation angle / time value pairs for controlling the servomotor. These default values are fed to a control loop, which includes a comparator and a control amplifier in addition to the servomotor and the position sensor. This outputs drive signals for the servomotor at its output. The servomotors are connected in parallel to these output signals or supplied via separate amplifier outputs with corresponding same control signals. They thus generate the same torque as the position-controlled servomotor, whereby the synchronicity of the servomotors is forced through a gearbox.

JP 2003 230 996 A describes a method for operating a servo press, by which a positional deviation between a loaded connecting rod and a non-loaded connecting rod is to be avoided. Here, a connecting rod is defined as a "master shaft" and the remaining connecting rods as a "slave shaft". During machining, the deviation of the "master shaft" with respect to a target position is monitored and passed on to the "slave shafts".

DE 10 2004 051 993 B4 describes a forming press, the drive is effected by means of a crank mechanism, each pressure point of the plunger is driven separately. The crank is driven indirectly by a freely programmable servo motor with an intermediate gear in the form of a gear ratio. By means of the servomotors, a flexible travel and speed characteristic is programmable for the movement of the plunger, wherein the gear ratio of the crank mechanism is taken into account. Position, speed and torque of the servo motors are controlled by means of an NC control so that the desired motion sequences can be achieved.

Known forming machines provide only unsatisfactory solutions for controlling the plunger.

The object of the invention is now to provide a forming machine with an improved tappet control available.

This object is achieved by a forming machine with the features of claim 1. Advantageous embodiments of the inventions are indicated by the features of the subclaims.

The forming machine according to the invention, in particular for cold and hot forming of metallic workpieces, for example metal sheets, preferably servo press, comprises at least one machine table with a tool receiving area for at least one lower forming tool and at least one plunger with a tool receiving area for at least one upper forming tool, wherein the plunger above the machine table is arranged and by means of a drive means, in particular by means of at least one servo motor, movably disposed against the machine table, wherein the drive means for the plunger at least two, preferably four, connecting rods which are coupled in an upper connecting rod bearing directly or indirectly to the plunger and wherein a control of the position and / or the position of the plunger is provided relative to the machine table and / or relative to a horizontal plane, wherein each of the at least two connecting rods is a Servomo tor, in particular via a gear via which the respective connecting rod is connected to the servo motor associated therewith, and wherein at least one, preferably at least three, position sensors are provided whose measured values are transferred to the control and an indirect or direct determination of the position or position allow the plunger relative to the machine table.

By arranged below the machine table drive the tilting tendency of the plunger is reduced. At the same time, it is ensured by regulating the position and / or position of the plunger relative to the machine table and / or relative to a horizontal plane, that the plunger is guided parallel to the machine table at each point of a working stroke. The combination of these two measures avoids tilting or slanting of the ram relative to the machine table, resulting in an improved forming process.

Since each connecting rod has its own drive, the entire force of a servomotor can act on a connecting rod.

By providing position sensors process parameters can be detected in a simple manner, which allows a direct inference to the position and / or position of the plunger. By measuring at least three such characteristics, it is possible by interpolation at least approximately to detect the position of the plunger relative to the machine table.

According to a further embodiment of the forming machine according to the invention at least three points of the shaft axes, and / or the bearing and / or the eccentric each at least one position sensor is arranged by means of which the respective actual angular position of the shaft axes, and / or the bearings and / or the eccentric are detected.

Also, by measuring the actual angular positions of said components, a process characteristic is detected in a simple manner, which allows a direct inference to the position and / or position of the plunger. By measuring at least three angular positions, it is possible by interpolation at least approximately to detect the position of the plunger relative to the machine table.

In accordance with a further embodiment of the forming machine according to the invention, at least three connecting rods and / or at least three pin axes and / or at least three guides and / or guide elements are arranged in each case at least one position sensor which determines the respective actual vertical position of the three connecting rods and / or the three Bolt axes and / or the three guides and / or guide elements can detect.

In this way, a process parameter is recorded, which allows a direct inference to the position and / or position of the plunger. Depending on the installation situation, the optimal sensor positioning can be selected.

According to a further embodiment of the forming machine according to the invention, the actual angular positions and / or actual vertical positions detected by the at least three position sensors are compared with desired angular positions and / or desired vertical positions and in the presence of one or more deviations of the actual angular positions and / or actual -Vertikalpositionen of the desired angular positions and / or desired vertical positions one or more servomotors so controlled that the one or more deviations, preferably zero, are minimized.

By comparing the actual positions with the desired positions, it can be detected when and if the path / time sequence of the plunger, or of the points at which the actual positions are detected, deviate from the desired positions of the ideal process sequence , If such deviations are present, the servomotors can be controlled individually or in combination in such a way that the deviations approach zero or settle around zero.

According to a further embodiment of the forming machine according to the invention, the desired angular positions and / or desired vertical positions are defined such that at an exact match of the actual angular positions with the desired angular positions and / or the actual vertical positions with the desired vertical positions of the plunger in a parallel position is positioned relative to the machine table and / or to a horizontal plane.

Thus, a control of the position of the ram is provided in a simple control technology, so that a desired in most forming processes desired parallelism of machine table and ram comes about.

According to a further embodiment of the forming machine according to the invention, the control of the servo motors by specifying the angular position of the motor axis and / or by specifying a phase offset.

Specifically, the specification of a phase offset allows a very precise and timely control of the servo motor with a high resolution of the travel.

According to a further embodiment of the forming machine according to the invention, the position sensors are non-contact sensors, preferably optical sensors, or contacting sensors, preferably measuring strips and / or position sensors.

Optical sensors have high resolution and accuracy and are well suited for use in an industrial environment. If it is not possible to use optical sensors, for example because the functionality of the optical sensors would be impaired by a high degree of contamination, it is possible to use contact sensors.

According to a further embodiment of the forming machine according to the invention so many position sensors are provided that can be detected by the returned from the position sensors actual angular positions and / or actual vertical positions, the actual vertical position of each articulation point of the connecting rod on the plunger.

By means of such an arrangement, it is possible to detect the position of all points of articulation and thus of all indirectly controllable via the control points of the plunger.

According to a further embodiment of the forming machine according to the invention, the control is a time-discrete control or a continuous-time control.

Depending on the plant design specifications or the respective customer's existing computer environment, the control can be executed time-discretely or continuously.

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

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

2 Forming machine according to 1 in a partially sectioned representation of the page and

3 shows an example of a controlled system for a forming machine with a servomotor

With reference to the 1 to 3 Now, an embodiment of the forming machine according to the invention will be explained

1 and 2 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 guided, vertically movable plunger 7 includes.

At one the pestle 7 facing top of the machine table 2 , in particular on a table top 3 , is a tool holder 3 for receiving the, not shown, lower forming tools of the machine table 2 intended. 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 manner known per se, they can have a grid of fastening 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 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 or guide grooves, arranged or 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 or stands 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 is guided on the vertical guides, 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 whose corner areas, coupled to the front and back of the side panel 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 downwards, ie with the assistance of gravity, to the machine table 2 and press the console 9 in the return movement back up against gravity. The console 9 pushes with her crosspiece 93 over the fasteners 8th during the forming movement 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 Left, side are through a first crankshaft 15 connected to each other, which is rotatable about a shaft axis A, 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 B. The two shaft axes A and B 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 circular rotational movement (eccentric movement) RB 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 the 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 A and B 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.

A rotary motion of the crankshaft 15 or 16 about its shaft axis A or B now leads to an eccentric movement or rotational movement RB of the two attached to the crankshaft eccentric elements, in particular 31 and 34 on the crankshaft 15 , 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 11A and 14A respectively. 12A and 13A , 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 movements RB all connecting rods move 11 to 14 at their upper connecting rod ends 11A to 14A vertically in a vertical movement labeled VB linear synchronously up or down, thus moving 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.

According to 1 At each of the bolt axes B1 to B4 is a position sensor 97 . 98 provided, via which the actual vertical position of the bolt axes is detected. Alternatively or additionally, position sensors can also be provided on the pin axes, the eccentric axes E1 to E4 or the shaft axes A, B, which detect the respective actual vertical position or actual angular position.

The bolt axes B1 to B4 define the articulation points of the connecting rods on the plunger. Due to the operative connection plunger 7 , Bolt axis B1 to B4, connecting rod 11 , Eccentric axis E1 to E4, shaft axis A, B, bearing 17 . 18 and machine table 2 , is the ram 7 always in a parallel position relative to the machine table 2 when the eccentric movements RB and the vertical movement VB are synchronized and the plunger 7 was already positioned in a parallel position at the beginning of the movements.

As long as these conditions are met, the actual vertical position of all pin axes B1 to B4 is identical. The machine table 2 itself is normally in a position parallel to a horizontal plane. If at least one pin axis B1 to B4 is different in an actual vertical position from the actual vertical positions of the other pin axes, the plunger is located 7 in a non-parallel position relative to the machine table 2 , Usually, it is desired a position of the plunger 7 parallel to the machine table 2 throughout the forming process. Under certain circumstances, it may also be desired a specific deviation of the position of the plunger 7 from a position parallel to the horizontal position.

The location of the pestle 7 is determined by the values of the actual vertical positions of the bolt axes B1 to B4, that of the existing position sensors 97 . 98 be returned, interpolated. Since one plane is defined geometrically by at least three points, one of the positions of the tappet is used for approximate determination 7 corresponding level from the measured values of the position sensors 97 . 98 at least the measurements of three position sensors required.

The resulting values of the actual vertical positions of the pin axes B1 to B4 and / or the already calculated by interpolation position of the plunger 7 representative level will be the scheme 100 provided with, from the target vertical positions of the bolt axes B1 to B4 or the desired position of the plunger 7 compared and adjusted if necessary.

The position sensors can except on the pin axes B1 to B4 or the eccentric axes E1 to E4 on the plunger 7 even, at the guides 45 , or the guide elements 75 . 76 be arranged to measure vertical positions. Alternatively or additionally, position sensors on the shaft axes A, B, the transmission gears 51 to 54 or the servomotors 21 to 24 be provided and measure angular positions of these components. Simple geometric relationships can be used to determine the position and / or vertical position of the plunger from these.

3 shows the block diagram of an exemplary control loop for the control 100 with a controller and a controlled system for controlling a controlled variable y to a specific value. The controlled variable y is, for example, the actual vertical position of the bolt axes B1 to B4. The aim of the control is to adjust the controlled variable y, in this case the actual vertical position of the bolt axes B1 to B4, with the reference variable w, in this case the target position of the bolt axes B1 to B4, and, according to the relationship e = w - y, to minimize the deviation e, or to eliminate.

Occurs a disturbance d, such. As unforeseen forces during the forming process, and acts on the controlled system, this has an effect on the parallelism of the plunger 7 relative to the machine table 2 , As a result, at least one actual vertical position of the pin axes B1 to B4 of the desired vertical position deviates from the reference variable w. The intended position measurement detects that the controlled variable y deviates from the reference variable w. According to the control deviation e, the manipulated variable u, z. B. the angular position of the motor axis of the servomotor 12 or the phase offset of the servomotor 12 , adjusted and so the deviation e corrected.

Thus the servomotors become 12 itself used as actuators by taking vertical actual positions of certain components or the plunger 7 through various angular positions or phase offset of the motors.

To measure the position of the plunger 7 Different measuring systems such as laser measuring systems or measuring strips or position sensors can be provided in the room. In the case of asymmetrical workpieces, different forming forces can occur on the workpiece, as a result of which the machine table 2 is charged differently at different locations. This has the consequence that on the connecting rods 10 to 14 different sized strains arise. To compensate for this, the eccentric need 31 to 34 be operated with different angular positions, resulting in different torques on the servo motors 21 to 24 result. Again, this can be done with the help of the scheme 100 realize.

The regulation 100 can be in a control facility 20 the forming machine 1 implements and so conveniently with the forming machine 1 are connected.

LIST OF REFERENCE NUMBERS

1

forming machine

2

machine table

3

tabletop

4

stand

5

crosshead

6

Workspace

7

tappet

8th

fasteners

9

console

10

counterbalance

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

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 sensors

100

regulation

A, B

shaft axis

B1 to B4

pin axis

E1 to E1

eccentric

P

pressing direction

S

plane of symmetry

RB

rotational motion

VB

vertical movement

w

command variable

y

controlled variable

e

deviation

d

disturbance

u

manipulated variable

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]
• JP 2003230996 A [0004]
• DE 102004051993 B4 [0005]

Claims (9)

Forming machine ( 1 ), in particular for cold and hot forming of metallic workpieces, for example metallic sheets, preferably servo press, comprising at least one machine table ( 2 ) with a tool receiving area ( 3 ) for at least one lower forming tool and at least one plunger ( 7 ) with a tool receiving area ( 70 ) for at least one upper forming tool, wherein the plunger ( 7 ) above the machine table ( 2 ) is arranged and by means of a drive device, in particular by means of at least one servomotor, is arranged movable against the machine table, wherein the drive means for the plunger ( 7 ) at least two, preferably four, connecting rods ( 11 to 14 ), which in an upper connecting rod bearing directly or indirectly to the plunger ( 7 ), and wherein a regulation ( 19 ) the position and / or the position of the plunger ( 7 ) is provided relative to the machine table and / or relative to a horizontal plane, wherein each of the at least two connecting rods ( 11 ) a servomotor ( 12 ), in particular via a transmission via which the respective connecting rod ( 11 ) with its associated servo motor ( 12 ) and wherein at least one, preferably at least three, position sensors are provided whose measured values are passed to the control and an indirect or direct determination of the position or position of the plunger ( 7 ) relative to the machine table ( 2 ) allow. Forming machine according to claim 1, wherein at least three points of the shaft axes (A, B), and / or the bearing 17 . 18 and / or the eccentric ( 31 to 34 ) at least one position sensor ( 18 ), which is the respective actual angular position of the shaft axes (A, B), and / or the bearing 17 . 18 and / or the eccentric ( 31 to 34 ). Forming machine according to claim 1, wherein at least three connecting rods ( 11 to 14 ) and / or at least three bolt axes (B1 to B4) and / or at least three guides ( 45 . 46 ) and / or guiding elements ( 75 . 76 ) at least one position sensor ( 18 ) is arranged, which the respective actual vertical position of the three connecting rods ( 11 to 14 ) and / or the three bolt axes (B1 to B4) and / or the three guides ( 45 . 46 ) and / or guiding elements ( 75 . 76 ). Forming machine according to claim 2 or 3, wherein the of the at least three position sensors ( 18 ) are compared with target angular positions and / or desired vertical positions and in the presence of one or more deviations of the actual angular positions and / or actual vertical positions from the desired angular positions and / or target positions. Vertical positions one or more servomotors ( 12 ) are controlled so that the one or more deviations, preferably to zero, are minimized. Forming machine according to claim 4, wherein the desired angular positions and / or desired vertical positions are defined such that, when the actual angular positions coincide exactly with the desired angular positions and / or the actual vertical positions with the desired vertical positions of the tappets (FIG. 7 ) in a parallel position relative to the machine table ( 2 ) and / or positioned relative to a horizontal plane. Forming machine according to one of the preceding claims, wherein the control of the servomotors ( 12 ) by specifying the angular position of the motor axis and / or by specifying a phase offset. Forming machine according to one of the preceding claims, wherein the position sensors ( 18 ) non-contact sensors, preferably optical sensors, or contacting sensors, preferably measuring strips and / or position sensors are. Forming machine according to one of the preceding claims, wherein so many position sensors ( 18 ) are provided so that by the of the position sensors ( 18 ) returned actual angular positions and / or actual vertical positions, the actual vertical position of each articulation point of the connecting rod ( 11 ) on the plunger ( 7 ) can be detected. Forming machine according to one of the preceding claims, wherein the regulation ( 19 ) is a time-discrete control or a continuous-time control.

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