DE202007010097U1 - Industrial robots, in particular for part transfer between two presses - Google Patents

Abstract

Industrial robots comprising:
a robot arm;
a slide mechanism (10, 10 ') mounted on the end of the robot arm (12, 12'') with slides (18), the slide slide mechanism (10, 10') comprising a base plate (14) for attachment to the robot arm ( 12, 12 ', 12 "), the carriage (18) is movable along a sliding axis (23) with respect to the base plate (14) and adapted to carry a tool (20);
characterized in that the carriage slide mechanism (10, 10 ') comprises:
a linear motor for its drive;
a rail (16) which is movable relative to the base plate (14) in the direction of the sliding axis (23) on which the carriage (18) is movably mounted; and
a coupling means connecting the movement of the carriage (18) with the rail (16) so that the relative movement of the rail with respect to the base plate implies a co-movement of the carriage with respect to the rail.

Description

Technical area

The The present invention relates generally to the field of industrial robots and in particular the area of the transfer between Presses used industrial robots.

State of the art

in the Automotive engineering is the transfer of parts such as body parts between two workstations, e.g. Pressing, usually from multi-axis articulated robots performed with a gripping tool equipped in the manner of a provided with vacuum suction gripper are. The gripping tool is at the end of the robot articulated arm which is programmed to cyclically sequence of movements, correspond to the different phases of the transfer process, in particular: approaching to a first press, positioning the gripping tool in the press and gripping the part (unloading), moving away from the press and moving in the press gap, approaching the second press and after all Inserting the part in the press and releasing the part (Loading the press).

The Speed of transfer between the two presses is of course one essential parameter for the productivity such a facility: the faster the transfer runs, the better higher the productivity be. The necessary time to cross of the press gap hangs this, of course from the time the robot takes to stand out from the first one Move away press, panning and / or move to the other press to move and to approach this. However, the necessary times for loading and unloading the presses are even more critical.

In Namely, press lines can Optimum production performance can then be achieved when the presses not be stopped and the transfer robots so during the very short time, for the press opens, remove and load the parts. In practice, due to the lack of rapidity of conventional Transfer robot stop the presses in the open position (upper Dead center) required. The mechanics of classic industrial robots lets the Accelerations and speeds that are necessary to to shorten the loading and unloading times.

One Another aspect that is bothersome in conventional systems will hang with the fact that the end of the robot arm during the Loading and unloading phases located in the immediate vicinity of the press, so If the press fails, there is a risk that the whole robot will be damaged.

GB-A-2 312 414 beats an industrial robot for the transfer of motor vehicle body parts between two presses in front. This industrial robot has a rotatable on its base mounted multi-axis arm and a slide slide mechanism on, which is attached to the end of the robot arm (6th axis). The slide slide mechanism is made from a frame, which with its upper part attached to the robotic arm is. The frame has at its two longitudinal ends a support plate with a camp up. In these camps, a drive rod is rotatable held, which defines a sliding axis and at its periphery between the bearings an external thread Has. One end of the drive rod is also equipped with a pulley provided over which they are coupled by means of a drive belt with an electric motor is.

Of the Carriage is carried by running along the frame guide rails. He is from the drive rod in the sliding direction with the help of two support members driven, which are fixed to the top of the carriage and threaded holes have, with the external thread the drive rod interact. A gripping tool in the form of a Fork with vacuum cups is fixed to the bottom of the carriage. By the operation of the electric motor can thus, depending on its direction of rotation the slide and with it the fork to one or the other end of the Be moved frame.

Of the Robot from GB-A-2 312 414 thus provides an answer to some the above mentioned Problems, due to its broad scope of action the slide slide mechanism, causing the robot arm not to must be driven close to the presses and thus from impact or other damage protected by the presses is. The phases end approach and loading / unloading without moving the robot by simply operating the carriage slide mechanism take place, which reduces the moving mass and the loading and unloading a little bit faster. The total duration of the press transfer is reduced because the robot moves simultaneously with the slide slide mechanism can move. Nevertheless, with the proposed slide slide mechanism, Using a screw-nut drive, no significant time gain the loading and unloading phases achieved as its dynamic performance remains weak.

It So there is a need for industrial robots for the press transfer with improved dynamic capacities.

General description of invention

One inventive industrial robot has a robot arm, at the end of a slide-slide mechanism is mounted with a base plate for attachment to the robot arm. The carriage is along a sliding axis with respect to the base plate movable and designed to carry a tool, for example a gripping tool. It is understood that the slide slide mechanism is driven by a linear motor and has a rail, which in relation to the base plate along the sliding axis, on the the carriage is movably mounted, movable. A coupling agent connected the movement of the carriage with that of the rail, so that the relative movement the rail with respect to the base plate in the same direction movement of the sledge in relation to the rail. Such a movement is effected by the coupling agent regardless of whether the Sled or the rail is the driving part.

Of the Use of a linear motor allows extremely high positioning accuracy together with a dynamic, higher is as with all other solutions. Dynamics is the coordinated administration of force (the counterpart the torque in a conventional rotary servomotor), the speed and the acceleration. In a linear motor There are no parts for converting a rotary motion into one straight-line movement. The power will be as efficient as possible directly exercised on the load, without losses due to the systems for transmission and conversion of the Movement (rotary motion in linear motion).

moreover pulls the design of the carriage, the rail and the coupling means summing up the speeds so that the sled and thus the tool carried by him at high speed can be moved.

The improved performance in terms of dynamics and precision of the Sled sliding mechanism, with the industrial robot according to the invention equipped, are particularly advantageous in the loading and unloading workstations such as Presses, which are thus shortened can.

It should also be noted that the rail is movable relative to the base plate and thereby the range of the robot can be extended while the sliding mechanism in the GB 2 312 414 attached to the arm of the robot approximately in its middle.

known manner If the linear motor is an electric motor that has been "unwound" in such a way that instead of of a torque (rotation) a rectilinear force over its Length generated, namely by building a magnetic field of motion. The linear motor typically has a fixed part (or stator), consisting of permanent magnets that use a magnetic path as a base for a coil form, which represents the movable or sliding part (rotor). Of the Linear motor generally has a linear encoder system with a optical or magnetic read head connected to a scale is. Furthermore, a frequency converter for position, velocity and acceleration control used to speed and the precision to manage the linear motor.

According to one Variant, the linear motor can be installed so that it directly acting on the rail. So can the fixed part of the linear motor on the rail and the moving part of the linear motor on the Be mounted base plate or vice versa. In this case, the Slide drive so indirectly and results from the coupling between rail and slide. This coupling can be with or several, attached to the base plate and the carriage drive belt which surround the rail and at the ends of which they are driven by pulleys guided are, so the movement of the rail inevitably the movement of the carriage in the same direction.

For the parts transfer between pressing the tool attached to the carriage is preferably a Gripping tool, in particular in the manner of a gripper with vacuum cups. By the big one Dynamics of the robot according to the invention In this application, the risk of damage to robot or press be minimized in case of failure of coordination, since leaving the press area can be done quickly.

apart From the press transfer of the invention, with a suitable gripping tool equipped Robot in the more general sense for A variety of ultrarapide handling operations are used, for Example for posting sales items.

At the sled can alternatively, other types of tools are attached, for example Cleaning, painting or welding tools. Such an industrial robot then would no longer perform part transfer or handling operations, but instead can then work on one or more stations and depending on Tool type perform different operations. The advantage of the improved Performance in terms of dynamics and precision is maintained, so that he is on his way to or from the respective workstation fast and accurate can move.

It has to be taken into account that the robot arm on which the slide-slide mechanism is mounted, depending easier to use after application (no articulated arm) or more elaborate can be mounted on a gantry crane and / or on a train can be moved along. Preferably, it is a multi-axis, articulated robotic arm.

Of the Slide slide mechanism is advantageous to the control unit of the robot connected so that it is controlled by this. He can do that managed as an auxiliary axis, giving great precision and good coordination (Synchronization) of the movements allowed. Alternatively, the Sled sliding mechanism from an independent control unit which makes it autonomous and mounted on a standard industrial robot This can be done at a low cost with a sliding mechanism equip.

In both cases it is clear that you can operate the slide slide mechanism, if the arm is not moved or when it is also pressed.

Description of the drawings

Further Particular features and features of the invention will become apparent from the detailed DESCRIPTION OF PARTICULAR EMBODIMENTS HEREINAFTER In order to explain with reference to the attached Drawings are shown. Show it:

1 to 3 FIG. 3: Schematic diagrams for explaining various positions in a variant of the slide slide mechanism of the present industrial robot; FIG.

4 to 8th : perspective views for explaining a preferred mode of use (transfer without rotation) of a robot according to the invention in a press line; and

9 to 11 : perspective views for explaining another use (linear transfer) of the robot according to the invention in a press line.

Detailed description of one preferred embodiment

A preferred embodiment of a slide slide mechanism 10 , the free end 12 (For example, on the 6th axis) of a multi-axis robotic articulated arm is mounted in the 1 to 3 shown. The slide slide mechanism 10 consists of a base plate designed as a board 14 for its attachment to the robot arm 12 one with 16 designated rail and a carriage 18 that to carrying a tool 20 is designed, here a gripping tool, for example in the form of a fork or a rectangular frame, with vacuum cups 22 is provided.

• – die Platine 14 weist zwei parallel zur Gleitachse 23 verlaufende, an den Rändern der Platine 14 angeordnete Schienen auf, die Stößel der Schiene 16 tragen und führen;
• – die Schiene 16 besteht aus zwei an seinen Rändern montierten Längsschienen, die Stößel des Schlittens 18 parallel zur Gleitachse 23 abstützen und führen.

The rail 16 is in relation to the board 14 movably mounted, the carriage 18 is in relation to the rail 1 6 movably mounted, both along a sliding axis 23 in the design of the 1 to 3 the execution of a horizontal translational movement to the tool 20 allows. The guidance and support in these movements is preferably ensured by mechanical guide systems with rails (not shown) distributed as follows:

• - the board 14 has two parallel to the sliding axis 23 running, at the edges of the board 14 arranged rails on, the ram of the rail 16 carry and lead;
• - the rail 16 consists of two longitudinal rails mounted at its edges, the rams of the carriage 18 parallel to the sliding axis 23 support and guide.

It is understood that the mechanism 10 is driven by a linear motor (not shown) and that the movement of the carriage 18 with the rail 16 is coupled, so that the relative movement of the rail 16 in relation to the board 14 a movement in the same direction of the carriage 18 in relation to the rail 16 causes.

The linear motor is preferably at the mounting interface between board 14 and rail 16 Installed. A coil, which forms the movable or sliding part (rotor) of the linear motor is, for example, under the board 14 the rail 16 fixed opposite. The fixed part (stator) of the linear motor, which consists of permanent magnets and forms a magnetic path as the basis for the coil, is then at the top of the rail 16 fixed opposite the rotor. For optimum operation, the linear motor advantageously has a linear encoder system with an optical or magnetic read-head connected to a scale mounted at the mounting interface between the board 14 and rail 16 is installed and allows precise position control of the engine and thus the rail. In addition, it is preferred to use a frequency converter that ensures position, speed and acceleration control in order to manage the speed and precision of the linear motor. Since the design and installation of the linear motors are well known to those skilled in the art, they need not be further described here.

Although not shown, one is Series of connecting and test cables of the linear motor and the suction cups connecting suction tubes mounted so that they are not exposed during the movements of any tension. The reference sign 25 indicates a protective jacket for the passage of these pipes and cables. The linear encoder system and the frequency converter are also not shown.

According to the first embodiment, the coupling is between carriages 18 and rail 16 realized with preferably toothed belt and pulleys. At each longitudinal end of the rail 16 is a pulley pair 24 fixed, taking the pulleys 24 one on the same longitudinal side of the rail 16 lying belt 26 is assigned (the disc-belt assembly is visible in the figures only for one side of the rail). It should be noted that every toothed belt 26 firmly on the board 14 and the sled 18 is attached, so that when operating the linear motor with the aim of the rail 16 on the sliding axle 23 to move along in one direction or the other, the assembly consisting of pulleys 24 and straps 26 the sled 18 inevitably moved in the same direction. The sled 18 So it runs at the same speed as the rail 16 , so that the traversing speed of the tool 20 in relation to the board 14 twice as high as that of the rail 16 ,

The in the 1 to 3 shown coupling is preferred because of its simplicity and efficiency; different types of transmission or reduction between rails 16 and sledges 18 however, they can be considered. Incidentally, the linear motor could be at the mounting interface between rail 16 and sledges 18 to be assembled.

In 1 is the carriage slide mechanism in its "extended" position, ie the carriage 18 is in the end position and the tool 20 extends as far as possible over the rail 16 out. This extended configuration is used, for example, for loading and unloading parts in a press. In 2 is the sled 18 in an intermediate position in front of the base plate 14 , his space requirement is compared to 1 reduced. In 3 the mechanism is "retracted": the carriage is on the opposite side compared to 1 in the end position, with the tool 20 only a little over the rail 16 protrudes.

The control of the carriage-sliding mechanism is preferably carried out via the control unit of the robot arm 12 , where it can then be controlled as an additional, so-called "auxiliary axis" (for example, 7th axis), so that the synchronization of the movements of the entire arrangement is improved. The robot is understandably articulated and has more axes the more complex the movements can be. No matter how the slide slide mechanism 10 is always controlled, of course, he can both simultaneously with the robot arm 12 as well as at its standstill can be operated.

For optimum performance, the robot and slide mechanism are in practice in quasi-permanent motion, with the movement of the part resulting from their combined movements. Of course, the range of the robot makes it possible to cover the distance between two presses. The slide slide mechanism 10 proves to be particularly interesting for shorter and faster movements. For example, during the loading and unloading phases, the substantial movement is preferably performed by the pusher mechanism because of its dynamic performance, while the robotic arm is used only for height and / or angle adjustments.

For the parts transfer between two presses can typically two modes of operation are possible: a linear transfer or a transfer with rotation.

The first case, transfer with rotation, is in the 4 to 8th shown. The part is rotated about 180 ° around itself during its transport between the presses. Consequently, during the loading and unloading phases, the same end of the rail is always in the vicinity of the press.

How out 4 to 8th can be seen, is a slide slide mechanism of in 1 to 3 shown type at the end of the 6th axis of a robot arm 12 ' assembled. The gripping tool has a mast which is attached at one end to the sliding carriage. On both sides of the mast vacuum cups are arranged. The length of the mast and the arrangement of the vacuum cups are selected so that the mast and the vacuum cups are in the extended carriage position (front end position, see 1 ) lie on the front of the rail. As a result, during the loading and unloading operations, it is possible to drive only the gripper mast with the suction grippers under the presses.

In 4 became the robot arm 12 ' to the right press 30 pivoted (seen from the robot); the carriage is about to grasp the tool 20 just shaped part 32 close to the front stop. The part 32 is then by the action of the slide slide mechanism 10 or by the combined action of mechanism 10 and robotic arm ultrarapide up to the in 5 pivoted position shown to the area under press as soon as possible ver to let.

As in 6 and 7 is shown, then the robot arm 12 ' and possibly the slide slide mechanism 10 pressed to the part 32 to turn 180 ° and put it in the position of 7 to bring before the left press 34 outside the press area. In the movement between the presses the slide is as in 6 shown near the rear stop to reduce the inertia during rotation. If the left press 34 opens, the part can then by combining the movements of the robot 12 ' and the slide slide mechanism 10 ultrarapide be deposited in the press, see 8th , and the area will be written "under press" (returning to a position similar to the one in 7 described position), so that the downtime for loading and unloading the press is kept low.

The case of the linear transfer is in turn in the 9 to 11 explained. A slide slide mechanism 10 ' of the type described above is at the end of the 6th axis of a robotic arm 12 '' assembled. The provided with vacuum suction gripper has here the shape of a rectangular frame. The attachment point of the gripping tool on the carriage is approximately in the middle of the frame; the vacuum cups are arranged at the four corners of the frame and in the middle thereof. It is clear that the skilled person can imagine a variety of configurations for this tool (shape, number of vacuum suckers, number of workpiece sensors), depending on the purpose and type of part to be gripped.

In 9 became the robot arm 12 '' to the right press 30 swung (seen from the robot) and the carriage lies to grasp the just formed part 32 near the end stop. In this linear transfer mode, the part becomes 32 moved substantially straight between the two presses, without rotation of the part 32 around itself (its orientation is maintained). How out 10 it became apparent that part 32 led to the center of the slide mechanism (the slide is in center position on the rail) and the robot 12 '' is just making a pivoting movement to the left press 34 out. In 11 finally, the pivotal movement of the robot is completed and the carriage is near the end stop on the rail to the part 32 in the press 34 store.

Claims (9)

An industrial robot comprising: a robot arm; one at the end of the robotic arm ( 12 ; 12 '; 12 '' ) mounted sliding mechanism ( 10 . 10 ' ) with carriage ( 18 ), wherein the slide slide mechanism ( 10 . 10 ' ) a base plate ( 14 ) for attachment to the robot arm ( 12 ; 12 '; 12 '' ), the carriage ( 18 ) along a sliding axis ( 23 ) in relation to the base plate ( 14 ) is movable and for carrying a tool ( 20 ) is designed; characterized in that the carriage slide mechanism ( 10 . 10 ' ) comprises: a linear motor for its drive; a rail ( 16 ), which in relation to the base plate ( 14 ) in the direction of the sliding axis ( 23 ), on which the carriage ( 18 ) is movably mounted, movable; and a coupling means which controls the movement of the carriage ( 18 ) with the rail ( 16 ), so that the relative movement of the rail relative to the base plate implies a co-movement of the carriage with respect to the rail. Industrial robot according to claim 1, characterized in that the linear motor partly on the rail ( 16 ) is mounted. Industrial robot according to claim 1 or 2, characterized in that the coupling means a relative movement of the rail ( 16 ) in relation to the base plate ( 14 ) and a movement in the same direction of the carriage ( 18 ) in relation to the rail ( 16 ), regardless of whether the carriage or the rail is the driving part. Industrial robot according to any one of the preceding claims, characterized in that the fixed part of the linear motor on the rail ( 16 ) is mounted and the movable part of the linear motor on the base plate ( 14 ) or vice versa. Industrial robot according to any one of the preceding claims, characterized in that the coupling means comprise at least one pair of pulleys ( 24 ), which at the longitudinal ends of the rail ( 16 ) and at least one around the rail ( 16 ) belt ( 26 ), which in the pulleys ( 24 ) and on the base plate ( 12 ) and on the sledge ( 18 ) is attached. Industrial robot according to any one of the preceding claims, characterized in that the tool ( 20 ) is a gripping tool, preferably with vacuum cups ( 23 ). Industrial robot according to any one of the preceding claims, characterized in that the base plate ( 14 ) a sliding system for the guidance and support of the rail ( 16 ) parallel to the sliding axis ( 23 ) and that the rail ( 16 ) at least one sliding system for the guidance and support of the carriage ( 18 ) along the sliding axis ( 23 ) having. Industrial robot according to any one of the preceding claims, in which the robot arm is controlled by a control unit, characterized in that the slide sliding mechanism ( 10 ) How an auxiliary axis is controlled by the controller. Industrial robot according to any one of the preceding claims, characterized in that the tool ( 20 ) is a gripping tool, preferably with vacuum cups ( 22 ).