EP0621093A1 - Transfer device for transferring workpieces in a press line - Google Patents

Abstract

The invention proposes a transfer device for transferring workpieces (43-47) in a press line, a large-component multiple stage press or the like in which the transfer of the workpieces from one processing station to the next is accomplished via cross members (37-41). In order to permit temporally and spatially independent transfer of the workpieces, the cross members (37-41) each have their own transfer carriages (32, 32a), these being movable independently of one another with several degrees of freedom. <IMAGE>

Description

The invention relates to a transport device for transporting workpieces in a press line, a large-part step press or the like according to the preamble of claim 1.

State of the art:

A press line consists of a series of individual presses, the type and number of which is determined by the range of parts to be manufactured.

A large-part step press is in principle a special case of a press line and, depending on the desired number of steps, consists of individual presses that are joined together to form a fixed assembly via the press stands and are driven by a drive shaft that runs in the transport direction.

The workpieces, for example sheet metal parts, can be used by press lines as well as large part step presses Processing stage to processing stage are transported by means of crossbeams, which are arranged at right angles to the direction of transport and are stored at their ends in transport trolleys. The transport trolleys are slidably mounted in and against the transport direction on two support rails running in the transport direction or the longitudinal axis of the press (DE 38 24 058 C1). In the known devices, the transport trolleys are connected to one another by push rods running in the transport direction. By moving in and against the transport direction, the transport step is carried out. The lifting and lowering movement of the crossbeams is carried out by lifting and lowering the mounting rail itself. To change the position of the workpieces, there is generally an empty stage between the work stages, in which the workpiece is temporarily stored (see DE 41 04 810 A1).

From DE 38 43 975 A1 it has become known to carry out a change in position of the workpieces in that the crossbeams are made rotatable with respect to their longitudinal axis, the rotary movement likewise taking place via a jointly driven swivel lever system from a cam mechanism.

As can be seen from DE 41 04 810 A1, transport devices of this type have the disadvantage that two part-specific cross beams are required per work step, each carrying out a maximum of half a transport step from the respective processing station to the intermediate empty step and back, an intermediate rest position being provided for the cross beams can be. These crossbars must be moved out of the press and replaced when the tool is changed with the sliding tables.

Setting up your own orientation station, intermediate station or empty level between the individual processing stations for intermediate storage and carrying out a change of position naturally also has the disadvantage that the support templates there are also part-dependent and must also be replaced when changing tools.

Since the empty stages or orienting stations are generally arranged in the area of the press stands, it is furthermore necessary to leave space on the side of the sliding tables for changing the parts-related accessories of these orienting stations in order to be able to stake the parts to be replaced thereon. However, both the orientation stations and the additional space to the side of the sliding tables take up a work space, which means the distance between the work stages and thus the overall length. B. enlarged a large section press. The increase in the distance between the work stages has the additional disadvantage that long distances have to be traveled with the workpieces, which takes time and energy.

Finally, the number of complex and inflexible curves for carrying out the parts transport control can also be disadvantageous in the prior art, with large weights of push rods and mounting rails and other movable units requiring the overcoming of large mass forces.

Object of the invention:

The invention has for its object to avoid the disadvantages described above in the prior art as possible and in particular to provide a transport device which is extremely economical and extremely Flexibility can work. The transport device should be independent of the design of a press with successive processing stations.

This object is achieved on the basis of a transport device of the type described in the introduction by the characterizing features of claim 1.

In the subclaims expedient and advantageous developments and improvements of the transport device are specified according to the main claim.

Advantages of the invention:

The transport device according to the invention initially avoids the disadvantages mentioned above. The basic idea of the invention is that universal mobility of the crossbeams for receiving and changing the position of the workpieces must be achieved. This is especially true when the individual press stages work independently of each other.

A universal mobility of a cross-beam receiving and transporting the workpiece is achieved, in particular, according to the invention in that at least one transport carriage or transport carriage is assigned to each cross-beam, which permits its own drive in at least two degrees of freedom, in particular a horizontal movement of the transport carriage in and against the transport direction and one Vertical movement of the trolley for upward and downward movement of the crossbar is provided. These transport movements can be controlled individually for each crossbeam, so that each crossbeam is driven completely independently of time and space within the press arrangement can be. Of course, the movements of the processing stages, e.g. the up and down movement of the press ram and the movements of the associated crossbeams arranged on transport carriages must be coordinated and synchronized with one another, which can be done by a higher-level control for the part-specific process of the transport carriage and the press control. A programmable drive for the trolleys is therefore synchronized with the press control.

If necessary, the transport trolley can also have a rotating device in order to be able to additionally carry out a pivoting movement of the crossbar about its longitudinal axis. By means of different lifting movements of two transport carriages arranged at the ends of a crossbar, a desired oblique position of a crossbar can also be set. This results in two additional degrees of freedom of the movement sequence.

Because the crossbeams can be moved in several degrees of freedom by means of the transport carriage, there is no need for separate orientation stations between the individual press stages or processing stations. Rather, the workpiece can be removed from the processing crossbar, which can be adjusted in different directions, from a processing station in a certain position by a vertical upward movement and transported by means of a horizontal, full transport step to the next processing stage and aligned accordingly. In this next processing station, the workpiece is then repositioned precisely by a vertical downward movement. This eliminates the complicated alignment of the workpiece in an orientation station located between the processing stations. Each transport trolley is therefore equipped with three different drives, if possible, in order to convert the cross-beam into three Degrees of freedom, ie a longitudinal movement, a vertical movement and a rotary movement about the longitudinal axis of the crossbar.

The pivotal movement of the workpiece by means of a rotary drive of the cross-beam also serves in particular to change an inclined position in the tool when the workpiece is being carried in and out, in order to achieve better freedom of movement with respect to the upper tool.

The cross members are usually held by two lateral transport carriages of the type described above. The transport trolleys are expediently arranged on two support rails which run in the longitudinal axis of the press and each connect at least two processing stages. The mounting rails can run in one piece through the entire press. The mounting rails are expediently provided with a height-adjustable mechanism by means of a separate drive, in order to lie above the stored upper tool when the tool is changed and thus enable the tool set to be moved out. Before this, the crossbeams can be pinned on the tool set by moving it above it.

The invention is particularly expediently designed in such a way that the press rams of the successive processing stages can work out of phase with one another. This means that a subsequent plunger z. B. moves up later than the previous one. Such a phase-shifted movement of the press rams can be coordinated with an equally phase-shifted movement of the cross-beams by the individual drive of the cross-beam carriages assigned to the processing stations. As a result, the distance between the cross members when removing or entering from or into the tool can be smaller than z. B. the The distance between the tool stages itself corresponds. The additional time saved by this phase-shifted sequence of movements for loading and unloading the workpieces into the machining stations corresponds to the angular offset of the phase shift of the ram or the transport carriage. This also results in better freedom of movement to the upper tool. Finally, due to the phase-shifted running of the individual press rams, a possibly provided common coupling can be chosen to be smaller, since basically not all rams are in the bottom dead center position at the same time.

When changing tools, the upper tool is moved onto the lower tool and released from the ram. Then the ram is moved to the top dead center position and the mounting rails are raised with the carriage and the crossbars. It is - as mentioned - advantageous if the crossbars are moved laterally over the tools and pinned onto them, i. H. be uncoupled from the transport vehicle. The carriages are moved into the stand area and the support rails are moved upwards so that the sliding tables can be moved out of the press with the tools and the pinned crossbeams. It is also advantageous if the crossbeams can be swiveled sideways when converting, if necessary, in order to create additional space and make tool changing easier.

The invention further provides that the insertion of boards in the first processing station can also be done by means of a crossbar. Due to several degrees of freedom on the transport trolley, larger transport steps can also be carried out, for example to adapt the system to a larger spider or a larger gripping device in this area.

Further details and advantages of the invention can be seen from the drawings and are shown in more detail in the following description of an embodiment.

Fig. 1

einen Schnitt nach der Linie A-A in Fig. 5 in einer ersten Pressenstellung,

Fig. 2

einen gleichen Schnitt in Fig. 5 in einer anderen Pressenstellung,

Fig. 3

einen Schnitt nach der Linie B-B in Fig. 6,

Fig. 4

einen Schnitt nach der Linie F-F in Fig. 7,

Fig. 5

einen Schnitt nach der Linie C-C in Fig. 2,

Fig. 6

einen Schnitt nach der Linie D-D in Fig. 3,

Fig. 7

einen Schnitt nach der Linie E-E in Fig. 4 sowie

Fig. 8

ein Bewegungsschaubild.

Show it

Fig. 1

5 shows a section along the line AA in FIG. 5 in a first press position,

Fig. 2

5 shows the same section in another press position,

Fig. 3

6 shows a section along the line BB in FIG. 6,

Fig. 4

7 shows a section along the line FF in FIG. 7,

Fig. 5

3 shows a section along the line CC in FIG. 2,

Fig. 6

4 shows a section along the line DD in FIG. 3,

Fig. 7

a section along the line EE in Fig. 4 and

Fig. 8

a motion diagram.

Description of an embodiment:

1 to 4 in side view and FIGS. 5 to 7 in front view show a press line, a large-part step press or a press assembly in general in various processing settings. The press assembly initially consists of the head pieces 1 to 4 and the press stands 9, 9a to 13, 13a one behind the other. The press stands are on the press tables 5 to 8 on which the sliding tables 14 to 17 are arranged. The press rams 18 to 21 with associated upper tools 26 to 29, which interact with the lower tools 22 to 25, are also shown in the press assembly.

In the longitudinal direction through the individual presses or the press assembly, support rails 31, 31a are mounted in height-adjustable carriages 30, 30a, which in turn are guided in vertical guides 63, 63a to 67, 67a (FIG. 5). Transport carriages 32, 32a are slidably guided in and against the transport direction of the workpieces on the mounting rails 31, 31a. The transport carriages 32, 32a in turn have vertical guides 33, 33a, on which carriages 34, 34a are mounted so as to be vertically displaceable (see FIG. 5). The carriages 34, 34a have pivotable receptacles 35, 35a, in which the crossbars 37 to 41 are fastened (FIG. 5). The cross members are with transport elements 80, z. B. suction or magnetic elements equipped on which a board 42 or the workpieces 43 to 47 are transported through the press stages.

The drive of the trolley 32, 32a takes place via z. B. programmable electric drives or the like, the drive being synchronized with the press control. Furthermore, the transport carriages 32, 32a for the crossbeams 37 to 41 electric motors can be driven in connection with pinions, toothed racks or toothed belt pulleys with toothed belts. As an alternative, a linear motor drive can be provided. Finally, the transport carriages 32, 32a can also be mechanically controlled by the individual presses, cam drives, levers, spline shafts, toothed belts and racks or the like being provided.

Through a higher-level control of the press system, part-specific travel paths of the transport trolleys can be specified.

When changing tools, the crossbeams 37 to 41 are pegged on locking pins 48, 48a to 52, 52a, which are preferably pivoted away laterally into an approximately horizontal position, preferably for placing or removing the tools on the sliding tables 14 to 17 according to the broken line in FIG. 3 can. The swiveling takes place outside or to the side of the press or the tool set. In another embodiment as shown in FIG. 4, the crossbeams 37 to 41 are pinned on brackets 53, 53a to 57, 57a attached to the upper tool and can remain assigned to the tool set.

The energy supply for the drives of the transport carriages 32, 32a takes place via a cable drag chain 58, 58a to 62, 62a (see FIG. 2 or 4).

Figures 1 and 2 show press rams 18 to 21, which work out of phase with each other. This is shown by arrows 93. 1, the plunger 18 hurries somewhat ahead of the plunger 19, while the plunger 20 is currently at bottom dead center and the plunger 21 performs a downward movement. In this phase, the transport carriages 32, 32a must be arranged outside the processing area, but they can already move in this direction. After the plunger 18 first moves upward in FIG. 1, the first transport carriage with crossbar 37 can also move first and guide the board 42 from the board feed belt to the first processing station 5 (FIG. 2). During this phase, the press ram 18 can already perform its downward movement (see arrow 93 in FIG. 2). Likewise, the second crossbar 38 takes over the workpiece from the first processing station 5 and transfers it with one full work step using the required degrees of freedom of movement to the second processing station 6. The further cross members 39 to 41 work analogously, the phase shift of the movement of the press rams 18 to 21 being carried out equally by the transport carriage 32, 32a of the individual cross members. This results in a considerable saving of time.

8 shows the staggered strokes of the press rams 18 to 21 with the curves 84 to 87 and the horizontal movement of the cross members 38, 39 with the curves 88, 89. The crank angle o or the time t is plotted on the X axis and the path s on the Y axis. The distance between the upper and lower boundary lines 91, 92 represents the step spacing or the transport step between the processing stations 5, 6. The center line 90 corresponds to half the step spacing with the parking or waiting positions 94 shown there for the transport trolleys 32, 32a.

The curve section 70 shows the retraction of the crossbar 38 into the tool 22 in order to remove the workpiece 43. In the curve section 71, the workpiece is transported into the tool 23 on the press ram 19. In the curve section 72, the crossmember 38 moves back out of the tool 23 and, when the ram 19 has reached point 73, is in a waiting position 94 between the processing stations 5, 6, ie from the collision area with the associated tool upper parts 26, 27. Um the dimension 74 (offset of the lower or upper dead center UT, OT), the press rams 18 to 21 are accordingly out of phase with one another. To the same phase shift as the press rams 18 to 21, the cross members 37 to 41 run out of phase with each other, z. B. the crossbar 38 in the transport step 71, the crossbar 39 by the dimension 75 catches up. This dimension must be smaller than the dimension of the step spacing minus the sheet metal part width.

The invention is not restricted to the exemplary embodiment shown and described. Rather, it also includes all professional developments and refinements within the scope of the inventive idea. In particular, the invention can be used both in a mechanical and in a hydraulic press.

Claims (10)

Transport device for transporting workpieces in a press line, a large-part step press or the like, with processing stations for the workpiece which are arranged one behind the other and in which upward and downward movable plungers with tools for workpiece shaping are arranged, the workpieces being fastened by means of cross members attached to longitudinally movable transport carriages the processing stations can be transported, characterized in that the cross beams (37 to 41) are assigned to transport carriages (32, 32a), each of which has its own drive independent of other transport carriages of other cross beams in at least two degrees of freedom, in particular for carrying out a movement in and against the direction of transport and a vertical lifting movement of the crossbar. Transport device according to claim 1, characterized in that the transport carriage (32, 32a) has a further rotary drive for carrying out a pivoting movement of the longitudinal axis of the crossbar. Transport device according to claim 1 or 2, characterized in that there are programmable drives synchronized with the press for driving the transport carriage (32, 32a). Transport device according to one of the preceding claims, characterized in that the drive of a hydraulic press ram (18 to 21) and / or the transport carriage (32, 32a) for the crossbeams (37 to 41) takes place by means of a superordinate control in order to achieve part-specific travel paths of the transport carriage to achieve. Transport device according to one of the preceding claims, characterized in that the press rams (18 to 21) are out of phase with respect to one another and the transport carriages (32, 32a) for the crossbeams (37 to 41) also run out of phase with one another to the same extent. Transport device according to one or more of the preceding claims, characterized in that the transport carriages (32, 32a) for the crossbeams (37 to 41) are driven by means of electric motors, pinions, toothed racks or toothed belt pulleys with toothed belts. Transport device according to one or more of the preceding claims, characterized in that the transport carriages (32, 32a) of the crossbeams (37 to 41) are driven by means of linear motors. Transport device according to one or more of the preceding claims, characterized in that the transport carriages (32, 32a) for the crossbeams (37 to 41) are driven mechanically by the individual presses, controlled by cam mechanisms, levers, splined shafts, toothed belts and racks or the like. Transport device according to one or more of the preceding claims, characterized in that the transport carriages (32, 32a) for the crossbeams (37 to 41) are guided on support rails (31, 31a) which are guided through the press or press line. Transport device according to claim 9, characterized in that the mounting rails (31, 31a) can be adjusted in height by means of separate lifting devices with height-adjustable slides (30, 30a) and guides (63 to 67 or 63a to 67a).

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