DE29923758U1 - Machine for punching, bending and / or assembling - Google Patents

Description

PATENT ATTORNEYS HÜBNER · DR. VONNEMANN & PARTNER GbR

Date: 05.12.2000

Lawyer's file: G 4303

UTILITY MODEL REGISTRATION

of the Lord

Harald Garth

Akams1
87509 Immenstadt

Designation:
Machine for punching, bending and/or assembling sheet metal parts

PAT010

DESCRIPTION

The invention relates to a machine for punching, bending and/or assembling sheet metal parts with at least one upper housing part and optionally one lower housing part, preferably several being arranged in a row so that the 5 upper and optionally lower housing parts are each horizontally aligned, fastened to one another and an upper housing part is vertically aligned with a lower housing part, and with at least one slide unit together with a slide guide on a housing part, wherein the slide unit is in engagement with a motor.

Furthermore, the invention relates to a method for operating such a machine.

The present invention relates generally to an index feed machining system in which a workpiece is subjected to punching, bending, deep drawing or other machining processes, all machining processes being carried out by a timed, indexed, step-by-step feed of the workpiece from one process step to the next. The workpiece is thus subjected to a series of machining processes one after the other until the entire machining process is completed with the final process. The individual machining processes are carried out in a single system. Depending on the workpiece and the number of process steps required, a large number of machines can be linked together in a modular manner according to EP 0 875 311. Due to their high production capacity, their short workpiece throughput times and their high degree of automation, they are particularly suitable for the mass production of sheet metal parts.

Another such machine is known from EP-A 0 103 885. The elongated upper and lower housing parts are connected to one another by spacers at the ends to form a frame. On the front and on

A number of slide units are attached to the back of each housing section, to which the appropriate tools for the respective workpiece to be produced are mounted. The housing sections contain worm shafts that end with the housing sections at the front. Several such housing frames can be connected to one another at the front, with the drive shafts being connected using curved tooth couplings.

DE-A 195 35 949 shows a similar state of the art, but here the housing parts extend between two vertical end bars and a front-side arrangement of several housing parts is not provided for.

A similar machine is also known from EP-A 0 127 156, in which the housing has two horizontal supports and two vertical supports, with all four supports having fixed torque taps for coupling with slide units.

DE-C 40 10 115 shows a machine for punching, bending and assembling, which differs from the generic machine in that housings with closed front panels are used, whereby a

A central wheel is mounted, with the circumference of which a large number of slide units arranged in a star shape are in driving engagement. Several such machine housings can be put together in modular fashion. Synchronizing the central wheels in the individual machine housings and even more so their star-shaped and radially operating slide units is problematic due to the necessary angle gears and couplings.

Depending on the type of product to be manufactured, the number of bending operations to be carried out in succession varies. A punching device is often installed upstream of the bending device, but sometimes the latter is not required. The existing machines are too large for simple bent parts, as they are designed for eight or more slide units or a multiple of these. Even if

Even if not all positions are occupied by slide units on such machines, the mostly unused angle gears also run, so that energy consumption and wear are unnecessarily high.

From DE 195 36 036 it is known to connect individual processing units to a crankshaft drive in such a way that the individual bending punches can be activated or deactivated as required. This is achieved by a piston-cylinder arrangement which is moved as a unit by the crankshaft when pressure medium is applied, which activates the unit. By venting the cylinder, the unit is deactivated and the piston moves up and down empty in the cylinder.

EP 0 875 311 describes a system in which the stations can be switched on or off by means of bevel gears that can be selectively engaged or disengaged. These bevel gears are mounted on a splined shaft that runs through the processing units, with the energy and movement of the individual processing units being supplied to the individual processing units by a common drive motor via the said shaft. The common drive shaft ensures that all processing units are moved synchronously with one another and synchronously with the feed rate of the workpieces to be processed. If a new workpiece is to be produced on such a system of processing units, not only do the individual tools have to be replaced and individual stations switched on or off if necessary, but the respective tool stroke must also be adapted to the workpiece. This requires replacing the cam disks that move the slide units. After replacing the cam disks, which determine the slide stroke due to their eccentricity, their angular division must also be adjusted so that the processing units move precisely with the feed rate of the workpiece. For such a tool change and setting up the machine for newly manufactured workpieces, changeover times of four to six hours are sometimes necessary.

required. The interaction of the workpiece feed and the processing units must be precisely coordinated in time and must not change even with work cycles of, for example, 500 strokes per minute. Due to the high cycle frequency with strokes of typically 40 to 50 mm, the processing units must not only absorb considerable cutting forces, but also considerable acceleration forces. When running in the machine, it is desirable that the stations can also be operated individually and that a common reference position can be set reproducibly.

The aim of the invention is to further increase the productivity of the machine. In particular, the necessary changeover times for adjusting the cam disk should be reduced.

This task is solved in a machine of this type for punching, bending and/or assembling sheet metal parts by driving the slide unit with a program-controlled synchronous motor. The movement cycle of the synchronous motor can be programmed. Instead of a cam disc, the stroke can therefore easily be changed by changing the program. It is not necessary to replace the cam discs. This advantageously reduces the changeover time.

As the actuating force of the synchronous motor is exceeded due to the high frequency and sometimes high forming forces, it is advantageous to have a gear between the motor and the slide unit, preferably designed as a cam disk, connecting rod or toggle lever. In this way, high process forces can be generated by appropriate gear reduction without having to dimension the synchronous motor too large, which would be disadvantageous.

When connected to rotary gears, such as cam disks, it is particularly advantageous if the program-controlled synchronous motor is designed as a rotary motor, preferably as a torque motor,

which is coupled to the slide unit via the gear link. The stroke can be easily changed by operating the synchronous motor over only a partial range. This means that the drive only uses a smaller angular range of the cam disk. This reduces the stroke. This means that no new cam disk is required. There is no need to replace the cam disk when converting, nor is there any need to adjust the angular position to synchronize the process steps. When running in the machine, the individual stations or the individual synchronous motor of the station can be controlled separately, which makes control during conversion much easier. In this way, individual stations can also be switched on or off as required without mechanically interfering with the energy flow. This means that gear links such as disengageable clutches and angle gears can be advantageously omitted.

In a further embodiment, the motors of several housing parts arranged in series are designed to be interchangeable. Such a standardized interface between the motors and the housing parts allows the individual machine to be constructed very flexibly. Not only can individual stations be easily switched on or off electronically, but surplus motors can also be avoided and used in other machines or elsewhere.

The synchronous motors used have a particularly high performance despite their small volume if the motor is water-cooled. The resulting waste heat can therefore be led directly out of the machine. Problems with uneven heating of the machine are advantageously avoided. The machine maintains its accuracy even over longer production periods.

The individual housing parts can be conveniently, quickly and easily connected to one another despite water-cooled engines, if the housing parts have cooling water inlet and

Have cooling water return lines for the engines assigned to them, which are coordinated in their position and, when connected in series, form a common cooling water supply and return line. These lines can then be connected to one another using quick couplings, for example.

In a further embodiment, the machine has a programmable logic controller that includes a current measuring device and an evaluation circuit that generates a signal as soon as the current falls below or exceeds a predetermined limit during a work cycle. As soon as a tool begins to become blunt, the necessary cutting and bending forces increase, so that the current consumption of the motor also increases. If a predetermined limit is exceeded, the machine can be shut down and preventive maintenance can be carried out on the tool. In this way, the machine can be prevented from accidentally producing rejects. The same applies if the current falls below a predetermined limit, for example as a result of a tool breaking. If a tool breaks, the machine can also be shut down and the tool replaced.

It is advantageous to provide that the machine is designed to switch off automatically if a limit value is exceeded or not reached. This prevents the machine from inadvertently producing rejects. As soon as a tool breaks or wears out, which leads to intolerable changes to the workpiece, the machine switches off automatically.

A standardization and modular composition of the machine can be achieved if an upper and a lower housing part are components of a uniform narrow housing box, the front of which does not exceed one

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upper and a lower slide unit are assigned. Such housing parts can be variably arranged next to one another and adapted to the respective workpiece.

In certain cases it is advantageous if the torque motor has a continuous shaft with output hubs at both ends. For example, the force can be introduced into a press symmetrically via knee levers. In addition, the rear and front housing parts with their slide units can also be driven by a common torque motor, as the torque motor has two output shaft ends.

The invention also enables the carriage units to be fitted with cam disks that protrude beyond the narrow housing boxes, by screwing a possibly two-part spacer block between two adjacent housing boxes according to a further embodiment of the invention. This increases the distance between the output shafts of adjacent housing boxes, so that carriage strokes of 50 mm and more can be carried out. Such spacer blocks, which can be easily inserted, also allow precise grid and cutting length adjustment, which is required due to deformation of the workpieces during processing.

According to a further embodiment, the machine has a front and a rear housing box row, with a front housing box being screwed to a rear housing box using connecting plates on the top and bottom. Alternatively, connecting plates extending over the entire length of the housing box row can be used. Both housing box rows have their own drive motors.

In some cases, it is advantageous to dispense with several drive motors for the individual slide units if a gear is connected between the motor and the slide unit, which is designed as a central wheel with driven pinions for the slide units that are in engagement with it.

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A correspondingly more powerful torque motor drives a large central gear. Pinions mesh with this central gear, which in turn drive slide units whose axes are arranged radially to the axis of the central gear. In this way, several slide units can be driven simultaneously by one central gear, advantageously reducing the number of individual drives required.

The set-up times are further reduced by the fact that the carriage unit is designed as a module with a motor.

It shows:

FIG. 1 a central vertical section through a housing box with torque motors,

FIG. 2 a front view of two housing boxes screwed together,

FIG. 3 a front view with three screwed housing boxes and a spacer block,

FIG. 4 the front view of a machine with two presses and four housing boxes as bending devices,

FIG. 5 is a vertical sectional view through a pair of front and rear housing boxes,

FIG. 6 is a plan view of a machine similar to Figure 5 with four housing boxes as bending devices,

FIG. 7 is a view of a double width housing box with two drives,

FIG. 8 is a vertical sectional view through the double-width housing box according to Figure 7,

FIG. 9 a vertical section through a double-width housing box with two symmetrically arranged torque drives,

FIG. 10 a press according to Figure 9 with a different arrangement of the drives,

FIG. 11 a press according to Figures 9 and 10, but with a single drive with two symmetrical output shaft ends,

FIG. 12 a front view of a cam disc,

FIG. 13 a front view of a single carriage unit,

FIG. 14 is a vertical sectional view of the individual carriage unit according to section line XIV-XIV in Figure 13,

FIG. 15 a front view of a machine with two housing boxes with linearly driven slide units, a central wheel with several

Slide units in a different design and a press,

FIG. 16 a front view of a housing box with central wheel, and

FIG. 17 is a vertical sectional view of the central wheel along section line XVII-XVII in Figure 16.

A housing box 10 is designed as a mirror image of a central horizontal plane 12 and has an upper housing part 14 and a lower housing part 16, both of which are connected in one piece. The housing box 10 is manufactured inexpensively from a block of cast steel, ferro-cast or light metal and is precisely milled in one clamping after the surface machining of the base surface. The front wall 18 is machined in such a way that parts of slide units 20 are assigned to the housing box 10.

Slide guides 28 in the form of guide strips for the slide are positively attached and screwed onto the front wall 18 of each housing box 10. Likewise, in the area of the central horizontal plane of symmetry, a tool receiving surface 30 is milled, which serves to positively receive a tool base plate 32 of a tool 34, whereby the tool base plate 32 is also screwed onto the front wall 18. In the design according to Figures 1 to 6, an upper and a lower motor housing are inserted into each housing box 10, each of which contains the torque motor 24. The housing boxes 10 have a width that is just large enough that the cam disks 38 of adjacent housing boxes 10 mounted on the output shafts 22 do not abut one another. Cam disks 38 for a slide stroke of 40 mm result in a minimum width of the housing boxes 10 of 176 mm. Larger cam disks, e.g. for a slide stroke of 50 mm, will result in a housing box width of approx. 200 mm.

Holes 40 are provided in the side walls of the housing boxes 10 so that adjacent housing boxes 10 can be easily screwed together, as is illustrated with machine screws 42 in Figure 2. Keys 44 in external grooves of the housing boxes 10 serve for exact guidance.

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Figure 3 illustrates a first embodiment of a sheet metal processing and assembly machine with four housing boxes screwed together, whereby three housing boxes 10 are equipped with slide units and a further housing box 11 is provided screwed on at the end. The torque motors advantageously eliminate the need for drive distribution boxes that would otherwise be screwed on at the end. In the prior art, such drive distribution boxes are necessary so that the upper and lower drive shafts are connected to one another in terms of drive. In the prior art, angle gears are screwed onto the drive box, which are driven by an electric motor, which is also not necessary in this case, since each slide unit is driven by its own torque motor. The drive shafts that would otherwise have to be pushed through the angle gears along the geometric axis 50 are also eliminated, whereby in the prior art all bending units are connected to a single motor in terms of drive.

Figure 4 illustrates a larger processing machine, which is however composed of the same basic units, namely the housing boxes 10 and 11. In addition, two punching presses 52, 54 are integrated into the modular system. The overall housing constructed in this way can nevertheless dispense with the motor drives arranged at the ends that would otherwise be provided.

Spacer blocks 56 are arranged between two housing boxes 10. These spacer blocks 56 make it possible to use larger cam disks for the slide units of the housing boxes 10 shown on the left. In addition, such spacer blocks 56 can be used to change the grid and cutting lengths according to the workpieces to be deformed.

Figure 5 shows a vertical sectional view through a twin housing consisting of a front row of housing boxes 10 and a rear row of housing boxes 10, the housing boxes of both rows being connected to the bottom wall on a

The two housing boxes are screwed onto the substructure, while on the deck side both rows of housing boxes are screwed together by a connecting plate 58. The housing thus formed therefore has slide units 20 on the front and rear. According to Figures 5 and 6, the connecting plate 58 extends over both rows of housing boxes. Alternatively, a separate, correspondingly narrower connecting plate can be provided for each pair of front and rear housing boxes 10.

Figure 7 shows a double-width housing box for a punching press. The slide unit 20 is driven by two output shafts 22 of two torque motors. Two cam disks are mounted on the output shafts 22, which drive the slide unit 20.

Figure 8 illustrates in a vertical section a similar embodiment to Figure 7. There, a double cam disk 38 is arranged on the output shaft 22 of the torque motor 24, which is moved by two scanning rollers 27 of the carriage unit 20.

Figure 9 shows another arrangement of a press in which two torque motors are arranged axially aligned in the housing box 10. The connecting rod 31 is moved via an eccentric 29, which is arranged on the output shaft 22, so that the tool 34 performs a corresponding stroke.

Figure 10 shows an alternative arrangement of two torque motors for driving a press. Here too, the drive is via the output shaft 22 to the eccentric 29. This in turn drives the tool 34 via the connecting rod 31.

Figure 11 shows a drive that is basically similar. However, this shows a torque motor that has output shafts on both sides that drive the connecting rod via the eccentric.

In all cases, the torque motors have an identically designed housing, the housing shell of which is cooled internally by a cooling channel 25. The motors themselves are round and additionally have a torque support which supports them in the housing box 10.

Figure 12 shows a cam disk whose outer contour is followed by the sensing roller 27. The sensing roller 27 is usually connected to the carriage unit. If the cam disk 38 is rotated between 0° and 45°, for example, it performs a maximum stroke. The same applies if it is rotated clockwise from 0° to 45°, for example, where it covers an angular range of 315°. The ratio of the rotary movement is different depending on the angular range in which the cam disk is operated. The advantage of the torque motor is that the rotation of the cam disk can be pre-programmed. It can also be reversible over only part of the angular range, so that only partial strokes are carried out.

Figure 13 shows the front view of a single slide unit 26. Parts with the same function are provided with the same position numbers as in the other figures. In contrast to the slide units shown in Figure 1, the vertical sectional view of the single slide unit according to Figure 14 shows an adapter plate 62 on which the slide 20 is mounted within the guide 28. The adapter plate 62 is also designed as a housing for the torque motor 24. In this way, the adapter plate 62 can be attached as an assembly, which also integrates the torque motor 24, to the front of a housing part by means of keys 44. This assembly contains all the necessary drive parts of the slide 20. The torque motor 24 drives the two cam disks 38 via its output shaft. A lower scanning roller 27, the axis of which is firmly connected to the slide 20, drives the slide in the direction of the workpiece. The upper roller 27, whose axle is fixed to

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the return plate 61, which in turn is firmly connected to the carriage 20, returns the carriage after a processing step.

Figure 15 shows several such linearly driven individual slide units, which are screwed as assemblies against housing boxes. On the left side of the machine shown, a linear feed 64 for material is provided. To the right, two upper and two lower linearly driven slide units 26 follow. This is followed by a housing box 10 with a central wheel 65. This station is formed by a total of eight slide units driven by this central wheel 65. Three of these slide units are arranged vertically above and below the central wheel axis 66 and one each on the right and left with an axis inclined relative to the horizontal.

To the right, there are upper and lower housing parts 14 and 16 with further slide units 26. The machine ends with a punching press 52. The structure of the station with central wheel drive can be seen in Figures 16 and 17. In the housing box 10, a single torque motor 24 is provided as a drive for slide units 26. The movement axes of these slide units 26 are arranged radially to the central wheel axis 66. For this reason, the slide units 26 are fastened to a central clamping plate 68 by means of hammer head screws (not shown) which engage in annular grooves 67. The clamping plate 68 is part of the housing box 10. Behind this clamping plate is the central wheel 65, in the outer gear 69 of which pinions 70 engage, which serve to drive the slide units 26. In Figure 17, the slide units are not shown for the sake of clarity. In this way, the eight carriage units of the embodiment can be driven by a single torque motor, which significantly reduces the investment costs for the drive motors.

The machine according to the invention for bending, punching and the like is characterized by the fact that drive shafts passing through the housing parts and with angular gears that can be coupled in each housing part can be advantageously dispensed with. Due to the low mass of the motors used, the machine hardly runs when stopped. In addition, quality control is possible by constantly measuring the bending and punching force curve during a work cycle. The individual stations can be switched on and off as required without the need for complex conversion work.

LIST OF REFERENCE SYMBOLS Housing box Housing box, drive distribution box Horizontal plane 10 upper housing part 11 lower housing part 12 Front wall 14 Slide units 16 Drive shafts 18 Torque motor 20 Slide units 22 Touch rollers 24 Slide guides 26 eccentric 27 Tool holding surface 28 Connecting rod 29 Tool base plate 30 Tools 31 Cam discs 32 Drilling 34 Machine screws 38 Keyways 40 Cooling channels 42 Angle gear 44 Electric motor 45 geometric axis 46 Punching press 48 Punching press 50 Spacer blocks 52 Connecting plate 54 Bearing ring 56 Return plate 58 60 61

• « · Adapter plate 62 Output axle 63 Linear feed 64 Central wheel 65 Central wheel axle 5 66 Ring grooves 67 Clamping plate 68 External gearing 69 pinion 70 module 10 71

Claims (14)

1. Machine for punching, bending and/or assembling sheet metal parts with at least one upper housing part ( 14 ) and optionally a lower housing part ( 16 ), preferably several being arranged in a row so that the upper and optionally lower housing parts ( 14 , 16 ) are each aligned horizontally, are fastened to one another and an upper housing part ( 14 ) is vertically aligned with a lower housing part ( 16 ), and with at least one slide unit together with a slide guide ( 26 ) on a housing part ( 14 , 16 ), the slide unit ( 20 ) being in engagement with a motor, characterized in that the slide unit ( 20 ) is driven by a program-controlled synchronous motor. 2. Machine according to claim 1, characterized in that a gear is connected between the motor and the carriage unit, which gear is preferably designed as a cam disc, connecting rod or toggle lever. 3. Machine according to claim 1 or 2, characterized in that the program-controlled synchronous motor is designed as a rotary motor, preferably as a torque motor, which is coupled to the carriage unit via the gear member. 4. Machine according to one of the preceding claims, characterized in that the motors of several housing parts arranged in series are designed to be interchangeable with one another. 5. Machine according to one of the preceding claims, characterized in that the motor is water-cooled. 6. Machine according to one of the preceding claims, characterized in that the housing parts which can be arranged side by side have cooling water supply lines and cooling water return lines for the motors assigned to them, which are coordinated with one another in their position and, when arranged side by side, form a common cooling water supply and return line. 7. Machine according to one of the preceding claims, characterized in that it has a programmable logic controller which includes a current measuring device and an evaluation circuit which generates a signal as soon as predetermined limit values of the current are exceeded or undercut during a working cycle. 8. Machine according to one of the preceding claims, characterized in that it is designed to switch off automatically when a limit value is exceeded or not reached. 9. Machine according to one of the preceding claims, characterized in that an upper ( 14 ) and a lower housing part ( 16 ) are components of a uniform narrow housing box ( 10 ), the front side of which is assigned no more than one upper and one lower carriage unit ( 20 ). 10. Machine according to one of the preceding claims, characterized in that the torque motor has a continuous shaft which has output shaft ends ( 22 ) at both ends. 11. Machine according to one of the preceding claims, characterized in that a possibly two-part spacer block ( 56 ) is screwed in between at least two adjacent housing boxes ( 10 , 11 ). 12. Machine according to one of the preceding claims, characterized in that it has a front and a rear housing box row and a front housing box ( 10 ) is screwed to a rear housing box ( 10 ) by means of a top and bottom connecting plate ( 58 ). 13. Machine according to claim 1, 3, 4, 5, 6, 7, 8 or 12, characterized in that a gear is connected between the motor ( 24 ) and the slide unit ( 26 ), which gear is designed as a central wheel ( 65 ) with output pinions ( 70 ) for slide units driven thereby and in engagement therewith. 14. Machine according to one of the preceding claims, characterized in that the carriage unit ( 26 ) is designed as an assembly ( 71 ) with a motor ( 24 ).