DEVICE FOR TURNING OF WORK PIECES

Abstract: A device for handling of work pieces (2) e.g. at operation of a robot (3) in a robot station (1), including a free, transportable load carrier (5) carrying at least one fixture (4), in which one or more work pieces (2) are arranged. Each fixture (4) is turnable around one or more turning axes relative to the load carrier (5) and are connected to at least one motor (16), by help of which it can be turned. Preferably a motor (16) is arranged separated from the load carrier (5) and brought into contact with each fixture (4) by connecting members (10, 14).

Description: DEVICE FOR TURNING OF WORK PIECES TECHNICAL FIELD The present invention concerns a device for the handling of work pieces, e.g. at operation of a robot in a robot station, including a load carrier which at least carries a fixture, in which one or more work pieces are arranged. The invention is not limited to be used at com¬ puter controlled robots but can be used at all kind of machining stations at which a work piece is shaped and which is turnable in relation to a tool, which in it self also can be turnable. However the invention preferably is usable for operating of welding robots. BACKGROUND TECHNICS At operation of different kind of machine tools showing robot functions, the work pieces mostly are ar¬ ranged in fixtures connected to the machine concerned. The bracing of the work pieces at that has proved to be time consuming, which has reduced the capacity of the machines. Also the other handling of the work pieces at the machines has influenced their capacity negatively. In addition to this such machines can not be fully automized but demand operators for changing work pieces and star¬ ting and stopping of the machines. At so called welding robots it is known to ar¬ range the work piece in a manipulator, in which the work piece can be turned around one or more turning axes in relation to the welding robot. The controlling of the turning movements of the manipulator is co-operated with the welding movements of the robot. Also here a time de¬ manding changing of the work pieces in the manipulator is demanded at the working of the welding robot. In order to increase the * capacity of the welding robot it can be found that two or more manipulators are arranged within the working area of the robot, by which changing of work pieces can be made in one manipulator on the same time as the welding robot welds the work piece in another manipulator. Also here an assistance of an operator is demanded at each robot, which is a drawback in plants with many co-operating robots. DESCRIPTION OF THE INVENTION The purpose with the present invention is to achieve a device for the handling of work pieces, e.g. at operating of a robot in a robot station, which does not show the drawbacks existing at operating of robot sta¬ tions at present. The purpose has been achieved by a de- vice including a separate, transportable load carrier, which at least carries one fixture, in which one or more work pieces are arranged. The invention is characterized in that the fixture is turnable around one or more tur¬ ning axes relative to the load carrier. This means that one and the same fixture can be turnable around one or more turning axes relative to the load carrier, as well as more fixtures on the load carrier can be individually turnable as well as uniformly turnable around parallel turning axes. Preferably each fixture is connected to at least one motor by help of which it can be turned. The turning of each motor and also each fixture also is controlled relative to the movements of the robot at its shaping of the work piece. Preferably one motor is arranged away from the load carrier and brought into connection with each fixture by connecting members when the fixture is to be turned e.g. during shaping. This means that the tur¬ ning movement of the motor is transferred to each fixture by connecting members, which can be common to all fixtu- res or arranged in connection with each fixture. Preferably one single fixture is arranged on the load carrier. A first connecting member at that is con¬ nected to the fixture and turnable together around a com¬ mon turning axis. A second connecting member is connected to the motor and shows a turning axis, which can be brought in alignment with a turning axis of the first • connecting member, to which the connecting members are mutually displaceable along the common turning axis. The second connecting member and the motor preferably are ar¬ ranged on a common carrying member, which is displaceble in a direction which is congruent with or parallel to the longitudinal direction of the common turning axis of the connecting members. The load carrier can be arranged on a conveying track extending through the robot station. At that the load carrier can be fixed in a desired position at the robot station by help of positioning members. The convey¬ ing track very well can be constituted by a horizontal roller track, but also by conveying tracks, at which the load carrier in different ways can be fixed during the transport, are possible. The carrying member which carries the motor and the second connecting member can be constituted by a swinging arm, which is swingable into and over the con¬ veying track around an axis, which is parallel to the common turning axis of the connecting members. The swing- ing arm is linear movable arranged on a travelling car between an off-position, in which the connecting members are separated, and a driving position, in which the con¬ necting members are connected and able to transfer the turning movement of the motor to the fixture. By the device according to the invention it has been provided for a possibility to apply work pieces in fixtures on load carriers at one and the same loading station, after that having the load carriers to pass one or more robot stations depending on which working opera- tions shall be carried out, and transporting to a deload- ing station, in which the work pieces are removed from the fixtures on the load carriers. By that each robot station can work completely without service concerning loading and deloading of work pieces. The invention is not limited to a transport of the load carriers upon firm transport devices as e.g. roller tracks, but also allows transports by all kind of transport devices and vehicles. The device according to the invention also allows that a certain storing of work pieces, which are to be shaped on load carriers respective deloaded from load carriers, can be done without limiting the utilizing of the robots in the robotstations. A main detail to make a preferred embodiment of the invention possible, in which the motor for turning the fixture is separated from the load carrier, is con¬ stituted in that the first connecting member shows one or more driving dogs which can be brought into a turning- transferring contact with the second connecting member, at which the driving dogs carries a positioning member, which in an off-position, in which the connecting members are separated, fixes the first connecting member in an angle relative to a position fixing member arranged on the load carrier. At that the positioning member is ar¬ ranged to be brought out of contact with the position fixing member when the connecting members are in a dri¬ ving position, i.e. connected. DESCRIPTION TO DRAWINGS Below the invention is described as an embodi¬ ment according to the drawings enclosed. Figure 1 shows schematically a part of a plant including several robot stations of which two stations are shown on this figure, which are connected by roller tracks for load carriers carrying fixtures. Figure 2 shows a robot station according to fi¬ gure 1 with a load carrier carrying a fixture, observed from the side and partly in a longitudinal section. Figure 3 shows the robot station according to figure 2 observed from above. Figure U shows a cross section through a roller track at the " robot station on figure 2 along the line A-A. Figure 5 shows a detail of a clutch, partly in a longitudinal section, by help of which a turning movement can be transferred to the fixture on the load carrier. The plant which is shown on figure 1 includes two robot stations 1 , in which parts 2 are welded toge¬ ther by help of a welding robot 3. Each part 2 is arrang¬ ed in a fixture 4, which in its turn is carried by a load carrier 5. The load carrier 5 is transported on roller tracks 6 from a loading station, which is not shown on the figure and which is connected to the parts of the plant indicated I on figure 1. The load carrier 5, after having passed the robot stations 1 , is transported to a deloading station, which is not shown on the figures, and which is connected to the part of the plant, which is in¬ dicated II on figure 1. The load carrier 5 is brought forward with a maintained orientation in relation to the surroundings when passing an angled part of the roller track 6. On figure 1 roller tracks 6 are shown with one and the same width corresponding to the narrower side of the load carrier, why the rolls are projecting from the sides of the tracks 6 to permit the load carrier 5 to project over the width of the tracks 6 in a certain transport direction. A similar robot station 1 as those on figure 1 is shown in detail on figure 2-4. A load carrier 5 has been transported into the station 1 from the right on figure 2 and been arranged in a desired position at the robot 3 of the station 1. The load carrier 5 includes a square frame 7 of square pipes resting on two supports 8 extending along two parallel sides of the frame 7. Each support 8 has a width which is greater than the distance between two rolls in the roller track 6, by which the load carrier 5 can be transported on the roller track 6 with its narrow side as well as its wide side in the transport direction. However on figure 2-4 a roller track 6 is shown which only permits a square load carrier to be transported in the two current transport directions, as its rims project above the roller in the track 6. The frame 7 on the load carrier 5 carries a stand 9, at the upper end of which the fixture 4 is turnable suspended at the end of an axis, the other end of which carries a first connecting member 10. The fixture 4 extends mainly horizontally from the stand 9 over the load carrier 5. When the load carrier 5 is in the desired posi- tion at the robot station 1, e.g. by braking and stopping means have been brought into the roller track, said load carrier 5 is brought to take a complete fixed position by help of four pneumatic cylinders 11 , which are vertically arranged below the roller track 6 and which are provided with conical mandrels 12, which are brought into contact with corresponding holes in the under side of the sup¬ ports 8 on the load carrier 5, and raises the same into contact with four seats 13 on the frame of the roller track 6. In the fixed position the first connecting mem- ber 10 on the load carrier 5 is aligned with the second connecting member 14, which is arranged on a swinging arm 15 together with a motor 16, to which the second connec¬ ting member 14 is connected. The swinging arm 15 is turn¬ able mounted in a bearing at one end on a travelling car 17, which in its turn is linearly travelling parallel to the roller track 6. The travelling car 17 is carried by two guides 18 and controlled by help of a pneumatic cy¬ linder 19. The swinging arm 15 is swingable between a position, which is away from the roller track 6, and a postion, wich permits that the first connecting member 10 on the load carrier 5 can be connected to the second con¬ necting member 14 on the swinging arm 15, by displacing the later by help of the travelling car 17. The swinging of the swinging arm 15 is carried out by help of a pneu- matic cylinder 20 connecting a bracket on the swinging arm 15 with the travelling car 17. The connecting members 10, 14 according to fi¬ gure 5, intended for transferring of the turning movement to the fixture 4 on the load carrier 5, are free from each other on figure 5. At that the first connecting mem¬ ber 10 shows a base plate 10.1 which carries two driving dogs 10.2 extending parallel to the centre line i.e. turning axis of the member. A sliding plate 10.3 showing holes for the driving dogs 10.2 is displaceable along these and also showing a positioning pin 10.4 which, in the position shown on figure 5, is engaged with a posi- tion fixing arm 21, which projects from the stand 9 on the load carrier 5. The sliding plate 10.3 is kept in a projected position by help of screw springs 10.5 sur¬ rounding each driving dog 10.2. The second connecting member 14 is connected to the motor 16 by a toothed dri- ving belt gear running inside the swinging arm 15, but not shown on the figures. The second connecting member 14 is constituted by a driving dog plate showing two holes 14.1 corresponding to the driving dogs 10.2 on the base plate 10.1 in the first connecting member 10. When the connecting members 10, 14 are brought together the driving dog plate 14 pushes the sliding plate 10.3 against the base plate 10.1 on the same time as the driving dogs 10.2 are forced into engagement with the driving dog plate 14 when the later is turned in that way that the driving dogs 10.2 are projecting into the holes 14.1 on the driving dog plate 14. At that the posi¬ tioning pin 10.4 on the sliding plate 10.3 is released from the positioning fixing arm 21 , by which the connec¬ ted connecting members 10, 14 can transfer the turning movement of the motor 16 to the fixture 4 on the load carrier 5. The turning movement of the motor 16 is con¬ trolled relative to the movements of the robot 3 by help of e.g. a computer in an already known manner. After finished operation the welding tools of the robot 3 are brought away from the fixture 4 and the part which is shaped, after which the swinging arm 15 is displaced by help of the travelling car 17 in that way that the connecting members 10, 14 are brought away from each other. After that the swinging arm 15 is turned away from its position over the roller track 6, after which the load carrier 5 with the fixture 4 can be lowered to the roller track 6 and transported away eventually to another robot station or a deloading station. In alternative embodiment of the invention the swinging arm 15 can be arranged on a travelling car 17 placed above the roller track 6, preferably at the side of the track. It is also possible to substitute the swinging arm 15 with an arm, which can be raised and lowered vertically above or below the roller track 6 and which can transfer turning movements from a motor 16 to the fixture 4 on the load carrier 5. Preferably the motor 16 is connected to a planetary gearing by which the fix¬ ture 4 can be turned by different speeds which e.g. can be 0-35 turns/min.

Claims: CLAIMS 1. A device for turning work pieces (2) in a working position e.g. at operation of a robot in a robot station (1), including a separate, transportable load carrier (3), which carries at least one fixture (4), in which one or more work pieces (2) are arranged, at which the fixture (4) is turnable around one or more turning axes relative to the load carrier (5), at which the fix¬ ture (4) is connected to at least one motor (16) by help of which it can be turned, c h a r a c t e r i z e d in that the motor (16) is arranged separate from the load carrier (5) and is brought in a connection with the fix¬ ture (4) by connecting members (10, 14) for turning the fixture (4) in the working position. 2. A device according to claim 1, c h a r a c ¬ t e r i z e d in that a first connecting member (10) is connected to the fixture (4) and turnable together with the same, that a second connecting member (14) is connec¬ ted to the motor (16) and shows a turning axis, which can be brought align with the turning axis of the first con¬ necting member (10), and that the second connecting mem¬ ber (14) is displaceable relativ to the first connecting member (10) along the common turning axis. 3. A device according to claim 2, c h a r a c - t e r i z e d in that the second connecting member (14) and the motor (16) are arranged on a common carrying mem¬ ber (15), which is displaceable in a direction which co- insides with, or is parallel to the longitudinal direc¬ tion of the common turning axis of the connecting members (10, 14). 4. A device according to claim 3, c h a r a c ¬ t e r i z e d in that the carrying member (15) is con¬ stituted by a swinging arm, which is swingable around an axis, which is parallel to a common turning axis of the connecting members (10, 14), into and over the transpor¬ ting track (6). 5. A device according to claim 4, c h a r a c ¬ t e r i z e d in that the swinging arm (15) is linearly movable on a travelling car (17) between an off-position, in which the connecting members (10, 14) are separated, and a driving position, in which the connecting members (10, 14) are connected and can transfer the turning move¬ ment of the motor (16) to the fixture (4). 6. A device according to any of the claims 2 to 5, c h a r a c t e r i z e d in that the first connec- ting member (10) shows one or more driving dogs (10.2), which can be brought into a turning transferring contact with the second connecting member (14), that the driving dogs (10.2) carries a position fixing member (10.3, 10.4), which, in a free position, in which the connecting members (10, 14) are brought away, fixes the angular po¬ sition of the first connecting member (10) related to a position fixing member (21) on the load carrier (5), and that the positioning member (10.3, 10.4) is arranged to be brought out of contact whith the position fixing mem- ber (21) when the connecting members (10, 14) are in a driving position, e.g. are connected.

Inventors: KAUNONEN ESKO, KEMPE MIKAEL, ROCKSTROEM NILS ERIK, RYDEN BENGT, KAUNONEN, ESKO, KEMPE, MIKAEL, ROCKSTROEM, NILS, ERIK, RYDEN, BENGT
Applicants: FIXTURTEKNIK I NYKOEPING AB
Application year: 1990
Main classification: B23Q7
IPC codes: B23Q7