The invention relates to an industrial robot having a movable carriage, on which a working device is mounted so it is vertically movable and can be lowered from a first region located above a safety level into a second region located below the safety level. A safety device can be positioned in a first location in the safety level in such a manner that the working device is prevented from being lowered into the second region. The safety device is movable into a second location, to allow the working device to be lowered from the first region into the second region.
Broad possible applications exist in industry for industrial robots, for example, for gantry robots in production lines in the automobile industry, in foundries, for the charging of machine tools, in welding processes, for palletizing, or for other handling tasks. A gantry robot can comprise two support beams arranged in parallel over a floor and a support rail arranged at right angles thereto and horizontally movable on the support beams. A vertically movable working device can be attached to a horizontally movable carriage on the support rail. Using such a gantry robot, the working device can be moved to arbitrary locations of the space enclosed by the support beams and the floor.
The working device has the apparatuses required for the application, i.e., e.g., a gripper for gripping automobile parts or a welding device for performing welding processes. Thus, for example, an industrial robot can be provided to perform specific welding tasks on multiple production lines extending in parallel. For this purpose, the working device can be raised up and moved over a location of a production line. The working device can be lowered there, the required welding task can be performed, and then the working device can be raised again to move it to another location.
The space (production region) covered by an industrial robot can be very large and can contain a plurality of processing machines. For monitoring tasks, it can be necessary to enter this enclosed space during the operation of the industrial robot. In order that this is possible without danger, safety measures are necessary to prevent persons from being harmed by control errors or machine failures. Even falling small parts or oil droplets are to be prevented. The industrial robot can be controlled in such a manner that the working device of the industrial robot is only lowered at very specific locations. However, a malfunction of such a controller can have fatal consequences. Therefore, persons move within the enclosed space in danger of being touched or even injured by the moving working device.
Therefore, in the case of a carriage which is only horizontally movable along a single support rail, a U-shaped channel is arranged in the prior art, which has openings closable using a slide at the locations at which the working device must be lowered. The channel and the slides are implemented as so solid that if the slides are closed, unintentional lowering of the working device is prevented and the working device can thus be moved without danger above the U-shaped channel. Persons can thus move without danger in the space below the U-shaped channel. This space is additionally protected from falling small parts or liquid droplets.
Such a U-shaped channel must be implemented as solid, however, which requires a high structural expenditure. In addition, the cleaning of such a channel is complex.
The object of the invention is to provide an industrial robot having a safety device, belonging to the technical field mentioned at the beginning, which is space-saving and can easily be cleaned well.
The achievement of the object is defined by the features of claim 1. According to the invention, the safety device is attached to the movable carriage of the industrial robot and is assigned to the working device of the industrial robot.
Such a safety device moves in the transport direction (i.e., transversely to the lowering direction) together with the working device and is not attached fixedly to the support beam of an industrial robot, e.g., a gantry robot. It is thus mobile. If multiple carriages having working devices, which may be moved independently of one another, are arranged on the same support beam, then a separate safety device can be attached to each carriage.
The safety device is smaller and only must be designed to catch a single working device. It can accordingly be implemented as lightweight and may be installed with less effort. The safety device is implemented as sufficiently stable so that the working device is prevented from being lowered into the region to be protected even in the event of a control error or a failure of the power supply. Finally, the safety device may be cleaned very easily, because it is designed much smaller and is therefore much better accessible than a previously known channel-shaped safety device.
A safety device according to the invention is preferably constructed from sheets or plates, so that materials such as chips or liquids can be collected. Such a safety device is used simultaneously as a lowering protector and as a drop protector. Alternatively, the safety device is implemented as a lattice, for example, and can therefore be constructed as particularly light. However, such a safety device only acts as a lowering protector or optionally as a catch protector for larger falling parts.
The carriage is preferably attached to a horizontal girder and is movable along the horizontal girder. The horizontal girder can be arranged at each of its ends on a fixedly installed column. The industrial robot can thus be moved along an axis (whose direction is defined by the horizontal girder and which can be designated, e.g., as the x-axis) and workpieces which are arranged along a line can be processed.
Alternatively, instead of being fixed on fixedly installed columns, the horizontal girder can itself be movable, for example, in that the columns are attached to rails or in that the horizontal girder is attached so it is movable at each of its ends to a crossbeam. The direction of the crossbeam can be designated as the y-axis and the working device can thus be moved or positioned in an entire spatial area (x-y plane formed by the horizontal girder and the crossbeams and the z-direction formed by the lowering direction).
The carriage to which the working device is attached can also be mounted on a rail, which forms a circular path or very generally a transport path on an arbitrary line. Alternatively, the carriage can also be mounted on one end of an extension arm or on the boom of a crane.
A downwardly protruding suspension, on which the safety device is mounted so it is rotatable, is preferably provided on the carriage (which is, e.g., a wagon having rollers). The pivoting outward and inward of the safety device can thus be ensured with a small design expenditure.
Alternatively, the safety device is mounted so it is linearly displaceable on the downwardly protruding suspension. The safety device can particularly be mounted so it is horizontally displaceable. In order that the safety device can be cleaned of materials such as chips and liquid droplets, which can collect in operation in the safety device, a stripper is provided. During a processing step, the safety device is only displaced linearly by, e.g., 80% in relation to the stripper, so that materials such as chips and liquid droplets are held back. In an emptying step, the safety device is displaced linearly by 100% and the materials are removed by the stripper from the safety device.
The safety device can preferably be moved in the first location into a first position, wherein material which has collected in the safety device is shaken out, and can be moved into a second position, wherein the collected material is held back in the safety device. Thus, in the first position, in which cleaning of the safety device can be performed by a flushing system, the collected materials can be flushed away via a surface and an edge of the safety device facing toward the floor. In the second position, in which processing of workpieces is enabled, the materials collected in the safety device, such as chips or liquid droplets, can be held back by a wall facing toward the floor.
The safety device is therefore preferably implemented as asymmetrical, in order to shake out material in the first position and hold back material in the second position.
The safety device is preferably substantially formed by a trough. The trough can comprise an inclined floor and inclined walls, so that a container is formed to be able to accommodate materials such as chips and/or liquids in a required quantity. The trough and its walls can be configured so that the materials collected in the trough are shaken out onto the floor upon pivoting out into a first position and the materials are held in the trough upon pivoting out into a second position.
Alternatively, the safety device is substantially formed by a plate. The plate can be rectangular and can comprise a border or a small fold on three of the four edges. Such a plate can have a small weight and can be used in industrial robots in which only small quantities of materials such as chips and/or liquids arise.
A flushing device is preferably arranged for flushing the safety device. The flushing device can particularly comprise a water nozzle for spraying off the safety device. Of course, the water can be preheated to a specific temperature. Solvent can also be added to the water. The water can be conducted at a high pressure to the water nozzle, so that the flushing can be performed more efficiently. The flushing device can be arranged as a washing station at any location which can be approached by the movable carriage. The flushing device can thus be arranged, for example, on one of the ends of a horizontal girder, along which the carriage is movable. The washing station is preferably arranged outside the region which must be approached by the working device in ordinary working operation.
Alternatively, a cleaning device is arranged, which cleans the safety device in a dry manner using compressed air or using rotating brushes. This has the advantage that the safety device is better protected from corrosion.
The safety device can preferably be pivoted out during the flushing or cleaning. With an asymmetrical safety device, it is particularly advantageous to pivot out the safety device into the position in which the safety device can be emptied. This has the advantage that the safety device can be cleaned particularly effectively.
A programmable control model is preferably provided for the industrial robot, in order to raise the working device into the first region located above the safety level and to pivot in the safety device, in order to move the working device over a workstation, in order to pivot out the safety device, and in order to lower the working device in the direction of the workstation. Such an industrial robot has the advantage that it can be operated without endangering persons.
Alternatively, mechanical and/or electronic means can be provided, for example, a mechanical profile attached along the horizontal girder, by which a switch is switched on or off depending on the longitudinal position of the carriage, for example, and the raising and pivoting in of the safety device are controlled accordingly. The mechanical profile can be configured according to the workstations, whereby it can be ensured that the working device is always raised between the workstations and the safety device is pivoted in. This has the advantage that two different systems can be used for the control of the work tasks of the industrial robot and the control of the safety-relevant functions.
Acoustic and/or optical means are preferably arranged to warn persons of movements of the carriage, the working device, and/or the safety device. The acoustic means can comprise a loudspeaker, a piezoelement, or a bell to generate a warning signal. The optical means can comprise a signal lamp, in particular an orange-colored, rotating, or blinking signal lamp. The safety can be additionally improved using such an industrial robot.
Preferably, at least one pneumatic drive and/or at least one electrical drive is arranged in each case for the movement of the carriage or for the pivoting in or pivoting out of the safety device, respectively. Such an industrial robot has the advantage in particular that proven and robust drives can be used for the movement of the carriage or for the pivoting in and out of the safety device, respectively.
Further advantageous embodiments and combinations of features of the invention result from the following detailed description and the entirety of the patent claims.
In the drawings used to explain the exemplary embodiment:
a shows a safety device in the first location,
b shows the safety device in the first position of the second location,
c shows the safety device in the second position of the second location,
a shows an industrial robot having a safety device in the first position of the second location,
b shows an industrial robot having a safety device in the first location, and
Fundamentally, identical parts are provided with identical reference numerals in the figures.
As outlined in
A processing base 4 is shown in
Alternatively, the workpieces can be on three parallel conveyor belts, for example, which are arranged at an angle of 90° to the horizontal girder 1, so that workpieces can automatically be supplied on the conveyor belts to the workstations 5.1, 5.2, 5.3 and guided away again. The working device 3.1 can comprise all required apparatuses and means to perform the desired processing of a workpiece. Such apparatuses and means can comprise drilling tools, milling tools, welding tools, soldering tools, coolants, or any other types of apparatuses or means. Thus, for example, a workpiece can be guided on a conveyor belt to a workstation 5.1, 5.2, 5.3. The workstation can comprise a holder, which receives and holds a workpiece from the conveyor belt. As soon as a workpiece is held in the holder, the working device 3.1 is lowered and the workpiece is processed using a tool of the working device 3.1. The holder of the workstation is also configured to place the workpiece back on the conveyor belt after the processing.
As outlined in
A safety level is defined by the channel 6, wherein the working device 3.1 is movable in a first region above the safety level along the horizontal girder 1, and wherein the working device can be lowered into a second region below the safety level after the opening of a shaft 7.1, 7.2, 7.3. The channel 6 arranged in the safety level causes comprehensive protection of persons and machines who are located in the second region below the safety level.
A vertical axis 23 is attached to the carriage 22 in order to raise or lower a working device 23.1. The vertical axis 23 can be implemented according to the prior art and can be formed, for example, from one or more rods displaceable in relation to the carriage 22, from profiles, or from plates. The drive of the vertical axis can again be electrical or pneumatic (not shown).
As sketched in
a shows a trough-shaped protective plate 38.3 in a first, pivoted-in location. The trough-shaped protective plate 38.3 can comprise a floor 38.31 as sketched in
In
In
An embodiment variant of an industrial robot according to the invention is shown in
As shown in
As shown in
In
Alternatively, the suspension 28.1 can be attached together with the protective plate 28.3 and the rotational axis 28.2 directly above the working device 23.1, instead of to the carriage 22. This has the result that the protective plate 28.3 is raised or lowered simultaneously with the working device 23.1. The protective plate 28.3 can be pivoted out before the lowering, so that the working device 23.1 can be used to accommodate or process a workpiece. After the accommodation or processing of the workpiece, the working device 23.1 can be raised and the protective plate 28.3 can be pivoted in. Chips and liquid residues which detach from the working device 23.1 can thus be accommodated by the protective plate 28.3. To protect persons, however, a safety controller must be used in this case in connection with a redundant safety brake, for example, according to EP 1 354 665 B1 (Güdel Group AG). It is therefore ensured that unintentional lowering of the working device 23.1 cannot occur. The execution and periodic function testing must meet the standards of ISO 13849-1 and must achieve corresponding performance levels.
Instead of a facility according to
In summary, it can be stated that an industrial robot having a safety device is provided by the invention, wherein a small design expenditure is necessary and the safety device can be easily cleaned.
Number | Date | Country | Kind |
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09 405 173.7 | Oct 2009 | EP | regional |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CH2010/000229 | 9/22/2010 | WO | 00 | 9/12/2012 |