Patent Grant
7484922
The invention relates to a transport apparatus for transporting workpieces from one machining station to the subsequent machining station of a press, press line, simulator, or the like.
Where the manufacture of a workpiece calls for a plurality of work operations, such as cutting or shaping, then for economic production the necessary individual operations are carried out in a transfer press or press line, as they are known. The number of tools then corresponds to the number of work stages that are necessary for the manufacture. In the presses there are transport devices with which the workpieces are transported from one workstation to the next.
In the case of transfer presses or large-component transfer presses, the transport devices comprise gripper or load-bearing rails that extend through the entire length of the shaping machine. In order to transport the workpieces, the load-bearing rails are fitted with gripper or holding elements. In this case, a distinction is made, depending on the movement sequence, between a two-axis transfer fitted with suction crossmembers or a three-axis transfer fitted with gripper elements.
As an additional movement, pivoting in order to change the attitude of the component during the transport step may be required. This attitude change can also occur using an orientation station arranged between the shaping stages.
The transfer movement is initiated via cams that are forcibly synchronized with the ram drive via movement transmission elements. The manufacture of large-area components, in particular, has led to the development of large-component transfer presses of greater and greater dimensions, based on the shaping force and the transport paths. Tool spacings on the order of magnitude of 5000 mm are entirely normal nowadays, and therefore corresponding transport steps are also necessary.
As a result of this development, the masses to be accelerated and braked in the transfer systems are completely opposed to the low masses of the components to be transported. Since the transport step is to be executed in an extremely short time, in order to achieve the greatest possible number of press strokes and therefore output of components, the system must have a high speed and therefore also acceleration and retardation.
A further disadvantage is the rigid movement sequence which is predefined by the cam drives. The optimum utilization of the free spaces between the lower and upper tool during the ram stroke to transport the parts is not possible.
In order to avoid these indicated disadvantages, current new developments concern replacing the previous transfer system with a corresponding number of transfer systems arranged between the machining stages and equipped with discrete drives. Such an arrangement is disclosed in EP 0 672 480 B1. Transfer systems arranged on the uprights are equipped with a number of drives that, mechanically linked to the movement transmission means, transport the components. As a special feature, the system can be re-equipped both as a two-axis transfer with suction beams and as a three-axis transfer with grippers. However, this universal use requires corresponding structural complexity.
A transfer device disclosed in DE 100 42 991 A1 is also arranged in each upright area. The transport apparatus is embodied as an articulated arm and is thus designed such that favorable clearances are possible relative to the ram movement. The articulated arm can thus move between upper and lower tool with a relatively small opening stroke of the press ram carrying the upper tool for removing the part.
Disadvantageous in this arrangement is the space required for avoiding a collision between the ram and the transfer apparatus. In the prior art, a free space is required between the upright and the ram so that the transport apparatus can execute the pivot movement. This leads to pressing the larger dimensions transverse to the part transport direction required.
The object of the invention is to further develop an articulated arm transport apparatus such that no additional space is required for the articulated arm transport apparatus between the upright and the ram.
The basic idea behind the invention is to modify the movement sequence of the articulated arm transport apparatus such that an adequate, in particular vertical, distance to the ram is provided. The geometry of the articulated arm parts is also changed and it is no longer executed in the same length, but rather the front articulated arm part to which the transverse crossmember is attached to the parts holding means is preferably shorter, which further improves the clearance. In addition, the articulated arm transport apparatus has an advantageous effect in the upright area and above the workpiece transport plane.
The articulated arm transport apparatus is mounted to the press uprights above the component transport plane. The first articulated arm part is dimensioned such that overlapping with the ram is not possible until there is a relatively large pivoting angle. Due to the ram movement, it is then situated in the area of its upper dead center, however, which reliably prevents a collision. The forward articulated arm part performs a pivoting movement directed upward relative to the point of rotation of the articulated arm parts. The first articulated arm part is pivotably borne on a carriage for performing a vertical lifting movement during the workpiece transport. The overlapping movement of the two articulated arm parts in connection with the vertical lift axis enables a freely programmable travel curve profile in a large band width, both for the component transport and for the unproductive movement. The unproductive movement can thus realize a very flat and therefore, relative to the clearance, extremely favorable travel curve. Thus it is possible to move the articulated arm into the free space that forms between upper and lower tool in an advantageous manner with a relatively small opening stroke of the press ram. The sequence results in less time for the component transport and leads to an increase in the press system's efficiency. Because of the dynamic lift axis, the articulated arm apparatus can be operated without additional structural measures, even at very different tool heights.
The entire transport apparatus comprises two articulated arm transport apparatuses that are arranged in the upright area in a mirror-image of one another and that are joined to one another via a transverse crossmember. The transverse crossmember is coupled to the front end of the shorter articulated arm part and carries the actual holding means for workpieces. Corresponding to the required functionality, the transverse crossmember can be provided additional degrees of freedom, such as pivoting in or counter to the direction of transport, an inclined position, or the ability of the holding means to traverse transverse to the part direction of transport, e.g. for dual parts. Each of the functions can be accomplished with a discrete drive on the transverse crossmember or by means of stationary drives via the articulated arm.
During the actual shaping process, the articulated arm transport apparatus is situated in a parked position in the upright area. The suggested design indicates a very favorable, narrow structure that is advantageous for the configuration of the press uprights. The latter can be dimensioned exclusively according to the strength required and do not require any additional width for the transport apparatus.
The movement transmission from the first to the second articulated arm part is accomplished via a fixed transmission. This enables a transmission adapted to the shaping stages and to the different tools, and thus enables a travel curve that is smooth and optimized in terms of movement.
Additional details and advantages of the invention result from the following description of an exemplary embodiment.
By way of example,
The arrangement of the articulated arm transport apparatus can be easily seen and is particularly advantageous for using the clearance between upper and lower tools. The movements of the transport apparatus do not interfere with the ram movement at all and thus the press does not have to be expanded to create a free space for the transport apparatus.
The travel curves 15 and 16 provide a visual illustration of the favorable relationships for very flat insertion, removal, and placement of the workpieces. The travel curve 16 illustrates the movement of the articulated arm without a workpiece. The travel curve 15 illustrates workpiece transport.
The articulated transport apparatus are each arranged on the press uprights by pair and in mirror image. The apparatus are joined via a transverse crossmember 17 to which the workpiece holding means 18 are attached.
The parts of the racks 25 and 26 that are oriented downward act in concert on the toothed wheel 27. The articulated arm 19 is securely connected to a common center point of movement 28 with this toothed wheel 27.
The movement sequences for the articulated arm 19 can be seen in the table 46. However, the only movements illustrated are those that result, when driven, using the same number of rotations for the drives 21 and 22. For instance, when both drives 21 and 22 rotate to the right for the same number of rotations, this causes a rotation of the toothed wheel 27 to the right via the drive train 23, 24, 25, 26 and thus also a pivoting movement to the right along a pivoting angle 47 by the articulated arm 19 connected to the toothed wheel 27. In this case, no movement takes place in the vertical (Y-) axis. Overlapping movement, i.e., pivoting and vertical movement, is attained e.g. when the drive 21 idles and the drive 22 rotates. As can be seen from the table 46, any desired travel curve in a plane can be attained using the appropriate rotation or idling of only the drives 21 and 22. Large transport paths can be executed with no problem with the suggested articulated arm transport apparatus. The identical movement sequences can also naturally be attained with other drive components. For instance, if the toothed wheels 23 and 24 and the racks 25 and 26 are replaced with separately driven toothed belts with corresponding toothed belt pulleys, the exact same movements can be traveled.
For the pivoting movement of the transverse crossmember 17 about the axis 38, a pinion gear 39 attached to the drive 36 drives the toothed wheel 40, which forwards the movement to the bevel gears 41 through 44.
Drive 37 can perform a potentially necessary moving apart of the workpiece holding means 18 for dual parts via a second system of bevel gears that are borne in the hollow shafts of the bevel gears 41 through 43 for the pivoting.
The invention is not limited to the described and illustrated exemplary embodiment.
| Number | Date | Country | Kind |
|---|---|---|---|
| 103 52 982 | Nov 2003 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/DE2004/002492 | 11/11/2004 | WO | 00 | 6/21/2006 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2005/046907 | 5/26/2005 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 1835579 | Westin | Dec 1931 | A |
| 4056198 | Boserup | Nov 1977 | A |
| 4065001 | Ohnaka | Dec 1977 | A |
| 4661040 | Cigna | Apr 1987 | A |
| 5106258 | Orii | Apr 1992 | A |
| 5452981 | Crorey et al. | Sep 1995 | A |
| 5584205 | Harsch et al. | Dec 1996 | A |
| 6712198 | Harsch et al. | Mar 2004 | B2 |
| 6715981 | Harsch et al. | Apr 2004 | B1 |
| 6968725 | Harsch et al. | Nov 2005 | B2 |
| 20010014279 | Harsch et al. | Aug 2001 | A1 |
| 20040261488 | Lauke et al. | Dec 2004 | A1 |
| Number | Date | Country |
|---|---|---|
| 26 28 734 | Dec 1977 | DE |
| 28 02 738 | Jul 1979 | DE |
| 35 25 988 | Jan 1987 | DE |
| 100 42 991 | Mar 2002 | DE |
| 0 114 774 | Aug 1984 | EP |
| 0 435 417 | Jul 1991 | EP |
| 0 672 480 | Sep 1995 | EP |
| 0 693 334 | Jan 1996 | EP |
| 1 129 800 | Sep 2001 | EP |
| 1 161 317 | Dec 2001 | EP |
| 2 346 071 | Oct 1977 | FR |
| WO- 0054904 | Sep 2000 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20070077135 A1 | Apr 2007 | US |
