JPS59120381A - Working device using robot - Google Patents

Abstract

PURPOSE:To improve working accuracy by moving a robot together with an object to be worked conveyor, holding an object to be worked fixing base movably in a conveyance direction, providing a connector between the robot and the fixing base and controlling the robot operation to follow up exactly the object. CONSTITUTION:A detector 34 of a speed detector 31 is rotated and the traveling speed of an article 13 is detected when a carriage 11 carrying an object 13 to be worked is moved by a conveyor 10 upon completion of teaching. A control device 23 moves a welding robot 17 by its moving device 16 at the equal speed of the article 13 at the same instant when a start signal is inputted thereto and said speed signal is inputted thereto. A cylinder 26 on the robot 17 is further actuated to fit a pin 27 into the through-hole 29 of a positioning plate 30, then the robot 17 and the article 13 are coupled to one body and are run integrally, whereby the welding of the article 13 is accomplished. If the conveyor 10 pulsates during this time, said pulsation is absorbed by a spring 15 as a fixing table 14 attached with the article 13 is attached via the spring 15 on the carriage 15 movably back and forth with respect to the carriage 11 in the traveling direction of the conveyor 10.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a processing device using an industrial robot such as a welding robot, and in particular to a device that uses an arm robot to process a workpiece that is being moved in a predetermined direction by a conveyance device. It is something to do.

As is well known, robots have recently come to be used frequently in various machining lines.For example, welding robots are being introduced most often on car body assembly lines, and painting robots are being introduced on painting lines. It's starting to look like this.

The advantage of introducing a robot is that it saves labor and improves productivity. Therefore, the workpiece is continuously conveyed by a conveyor device such as a belt conveyor or slat conveyor, and the robot processes the workpiece during the conveyance. It is usual to apply

However, when a workpiece being transported is processed by an arm robot, various problems have arisen because conventionally, a device configured as shown in FIG. 1 has been used.

FIG. 1 is a schematic diagram showing an example of a processing device using a welding robot 1, in which a workpiece 2 such as a car body is fixed to a conveyor 4 provided on a conveyor 3, and the conveyor 4 is When the origin detector 5 consisting of a limit switch, a phototube switch, etc. is operated, a start signal is input to the control device 6, and as a result, the control device @6 sends a signal to the conveyor 3 based on data stored in advance by teaching. The welding robot 1 is operated based on the output signal, which is output while being corrected by a device signal and a speed signal constituted by a connected detector 7 such as a rotary encoder,
A welding gun 9 attached to the tip of the arm 8 performs spot welding on the workpiece 2. Therefore, in the above-mentioned conventional device, the welding robot 1 is operated while correcting the pre-stored data using the device signal or the speed signal constituted by the detector 7. Therefore, when the conveyor 3 pulsates, the welding robot 1 is operated. Since there is a limit to the responsiveness of the arm 8, the arm 8 may not accurately follow the workpiece 2, and there is a risk that machining accuracy may deteriorate. In addition, in the above-mentioned conventional device, for the same reason as mentioned above, it takes time to calculate the movement (trajectory) of the welding robot-1, and accordingly, the operating speed of the arm 8 must be increased. This, combined with the lack of mechanical rigidity of the welding robot 1, causes the arm 8 to vibrate, which also poses a risk of deteriorating machining accuracy. In order to eliminate such inconvenience,
Although it would be possible to use a control device that allows for a faster rod-driving speed, there is a problem in that the control device becomes quite expensive. Furthermore, in the conventional device, the speed etc. of the conveyor 3 are detected and the welding robots 1 to 1 are made to follow the workpiece 2 based on the detection result, so in order to improve the followability of the welding robot 1, There are problems that require special know-how, such as teaching that takes into account the characteristics of the conveyor 3 such as pulsation, and the operation of the welding robot 1 during teaching and the operation of the welding robot 1 during playback. Because of this difference, if the conveyor 3 temporarily behaves abnormally for some reason, an unexpected accident may occur.

This invention has been made in view of the above circumstances, and aims to provide a processing device that allows the movement of a robot to accurately follow the workpiece, and therefore can produce products with good processing accuracy. The feature is that the robot movement device moves the robot at almost the same speed as the transport device for the workpiece, while the fixed table on which the workpiece is fixed is placed on a trolley installed in the transport device in the direction of transport. The present invention is characterized in that a connector is provided on one of the robot and the fixed base, which is held via an elastic body so as to be able to move back and forth, and which connects and integrates the robot and the fixed base during processing.

Embodiments of the present invention will be described below with reference to FIGS. 2 to 5.

FIG. 2 is a perspective view schematically showing an embodiment of the present invention, and FIG. 3 is a plan view thereof. A rail 12 along the running direction of the competition 1710 is laid, and a workpiece 13 such as an automobile body is laid.
A fixing base 14 for fixing the conveyor 10 is placed on the rail 12.
It is installed so that it can move back and forth along the direction of travel.

4- Here, the trolley 11 may be connected to the conveyor 10 and run on the floor, or may be detachably attached to the conveyor 10. Further, elastic bodies, that is, springs 15 are arranged between the front and rear ends of the fixed base 14 and the trolley 11, and the springs 15 absorb the pulsation of the conveyor 10.
In other words, the movement of the workpiece 13 is made smooth.

On the other hand, robot moving devices 16 are arranged in parallel on the side of the conveyor 10, and welding robots 17 are installed on each of the robots 1 to 16. The robot moving device 116 moves the welding robot 17 at approximately the same speed as the conveyor 10, that is, at approximately the same speed as the workpiece 13, and for example moves the robot body 18 in a direction parallel to the traveling direction of the conveyor 10. The robot body 18 is supported by rollers (not shown) so as to be movable, and a feed screw shaft (not shown) such as a ball screw shaft screwed into the robot body 18 is rotated by a drive motor 19 such as a pulse motor.
It is configured to move the welding robot 17. In addition, the welding robot 17 has an arm 20 that moves up and down, back and forth, and rotates attached to a ram 21, and a welding gun 22 attached to the tip of the arm 20.
The device is configured to repeatedly perform the taught operation based on the output signal from the device 3.

Furthermore, a connector 24 is provided that connects and integrates the robot main body 18 and the fixed base 14 together. FIG. 4 is a schematic illustration of the coupler 24. A cylinder 26 is attached to the robot body 18 to move the rod 25 forward and backward toward the fixed base 14. , a plate 28 having a pair of bins 27 protruding toward the fixing base 14 is attached. On the other hand, a positioning plate 1-30 having a through hole 29 into which the bin 27 is fitted is attached to the fixed base 14. Therefore, the coupler 24 is configured to connect and integrate the welding robot 17 and the fixing table 14, that is, the workpiece 13, in a predetermined positional relationship by fitting the bin 27 into the through hole 29.

Furthermore, a speed detecting device 31 is arranged on the side of the conveyor 10, and the speed detecting device 31 is connected to a wire stretched parallel to the conveyor 10 by a pair of pulleys (or rollers or rollers) 32. The sensor 34 is composed of a rotary encoder or a tacho generator connected to one of the pulleys 32, and a detector 34 connected to the above-mentioned control device 23. The protrusion 35 provided on the stand 1111 pushes the protrusion 36 provided on the wire 33 to cause the wire 33 to run, and the accompanying rotation speed of the pulley 32 is detected by the detector 34 as the running speed of the conveyor 10. .

An origin detector 37 consisting of a limit switch or a phototube switch is connected to the control device [23, and the origin detector 37 detects when the carriage 11 reaches a predetermined processing start point. It is installed at a position where it is turned on by the switch, and when it is turned on, it outputs a start signal to the control device 23.

Next, the operation of the processing apparatus configured as described above will be explained.

First, the welding robot 17 is taught.

Teaching can be performed in the same way as with conventional robots, but in the above device, the fixing table 14 with the workpiece 13 attached, the welding robot 17, and the bin 27 inserted into the through hole 29 of the positioning plate 3o. The conveyor 10 is stopped and the welding guns 22 are sequentially moved to the welding points of the workpiece 13 by fitting together, and the coordinates of the welding points and the movement route are sent to the control device 23. Teaching is done by memorizing.

After the teaching is completed, before starting the actual operation, the welding robot 17 is kept on standby at the left end side of the robot moving bag @16 in FIG.
Similarly, the protruding piece 368- attached to the wire 33 is also kept on standby at the left end side in FIG. When the cart 11 carrying the workpiece 13 is moved by the conveyor 10 in this state, the protrusion 35 provided on the cart 11 first hits the protrusion 36 and pushes it, so that the workpiece 13 is moved through the wire 33 and the pulley 32. Since the detector 34 is rotated, the traveling speed of the conveyor 10, that is, the workpiece 13 is detected by the detector 34. Next, the truck 11 turns on the origin detector 37, and a start signal is input from the origin detector 37 to the control device 23.

Then, the gate in the control device 11ffi23 opens and the speed signal output from the detector 34 is transmitted to the control device 23.
At the same time, a drive signal is output from the control device 23 to the drive motor 19 in the robot moving device 16 in order to move the welding robot 17 at a speed equal to the moving speed of the workpiece 13. Furthermore, the cylinder 26 provided on the robot body 18 operates based on the signal input from the control device 23, and as a result, the plate 28 is pushed out and the bin 27 is fitted into the through hole 29 of the positioning plate 30. Thus, the welding robot 17 and the workpiece 13
are substantially combined and integrated. Welding robot 17
is moved by the robot moving device 16 at the same speed as the workpiece 13, and performs welding work on the workpiece 13 based on an output signal from the control device 23 based on data stored by teaching.

If the conveyor 10 pulsates in its running direction during welding in this way, the fixing base 14 to which the workpiece 13 is attached may move back and forth with respect to the cart 11 in the running direction of the conveyor 10. Since the conveyor 10 is attached to the carriage 11 via the spring 15, the pulsation of the conveyor 10 is absorbed by the spring 15 and does not particularly affect the workpiece 13. In addition, since the robot main body 18 and the workpiece 13 are substantially connected and integrated by the coupler 24, even if the conveyor 10 pulsates, the welding robot 17 and the workpiece 13 will not connect to each other as expected. In other words, the relative positions of the two do not change. In other words, the i! Welding robots 1 to 17 are moved to robot moving device 1.
Since it is not necessary to pulsate by 6, the control 611 device 2
3 to the drive motor 19 from the input 13 from the detector 34 each time the motor A710 pulsates.
Therefore, the calculation speed of at least the portion of the control device 23 that controls the movement of the welding robot 17 does not need to be particularly fast.

In addition, in the above device, the welding robot 1-17 and the workpiece 1
3 is not affected by the pulsation of the conveyor 10, the positional relationship between the welding robot 17 and the workpiece 13 is the same as during teaching, and therefore -
(Because there is no need to correct the III control signal based on the data stored by teaching due to disturbances such as pulsation of the conveyor 10, it is necessary to particularly increase the calculation speed of the III device 23 in this respect. There isn't.

Overall, with the above-mentioned device, it is possible to perform processing while maintaining the relative position of the welding robot 17 and workpiece 13 in the same positional relationship as in teaching, which is performed with the workpiece 13 fixed. , it is possible to use a conventional general control device 23 whose calculation speed is not particularly high, and in addition, the welding robot 17 operates in the same manner as during teaching and performs processing without being affected by disturbances such as pulsation of the conveyor 10. Therefore, processing can be performed with high precision.

When the machining is completed as described above, the robot body 1
The cylinder 26 provided at 8 pulls back the plate 28 and extracts the bottle 27 from the through hole 29 of the positioning plate 30, thereby disengaging the robot body 18 from the fixed base 14, and then the welding robot 17 moves. It is moved in the opposite direction by the device 16 and returned to the starting position to prepare for the next processing.

In the above embodiment, the traveling speed of the conveyor 10 is detected by the detector 34, and the welding robot 1 is controlled by controlling the robot moving device 16 based on the detection result.
Although an example in which a so-called closed-loop system for controlling the moving speed of 7 has been described, the present invention is not limited to the above-mentioned embodiment, and may also be applied to a configuration in which a so-called open-loop system is adopted. good. FIG. 5 is a schematic diagram of an example configured as an open loop system, in which the control device 38 has a function of controlling the welding robot 17, and also provides a signal to the drive V7iat 39 that drives the conveyor 10.
It also has a function to run the conveyor 10 at a predetermined speed, and the welding robot 17 is normally run at a constant speed, and a start signal input from the origin detector 37 starts the welding robot 17.
The welding robot 17 is controlled based on data memorized by teaching at the same time as controlling the robot moving device @16 so as to move it at the same speed as the conveyor 10. Note that the other configurations are the same as in the embodiment described above. Therefore, even if the open loop system is adopted as shown in FIG. 5, the relative position between the welding robot 17 and the workpiece 13 can be kept constant, so it is possible to keep the relative position of the welding robot 17 and the workpiece 13 constant. effect can be obtained.

Furthermore, the robot moving device 16 according to the present invention is not limited to the configuration shown in the above-described embodiments; instead, a rack attached to the robot body 18 is engaged with a pinion, and the pinion is rotated by a drive motor 19. The welding robot 17 may be moved by moving the welding robot 17. Furthermore, the present invention can be applied not only to the case of welding the workpiece 13 but also to the case of applying processing such as painting.

As is clear from the above explanation, the processing device of this invention
:The robot movement device moves the robots 1 to 1 at almost the same speed as the workpiece conveyance device, while the fixed table on which the workpiece is fixed is placed on a trolley provided in the conveyance device in a direction relative to the conveyance direction. held via an elastic body so as to be able to move backward;
Furthermore, since the structure is such that a coupler that connects and integrates the robot and the fixed base during processing is provided on one side of the robot and the fixed base, even if the conveyance device pulsates, the elastic body and the coupler It is possible to maintain a constant positional relationship between the robot and the workpiece, and therefore it is possible to perform highly accurate machining that is not affected by the pulsation of the transport device, and it is also possible to correct the control signal according to the pulsation of the transport device. Since there is no need to do this, a relatively inexpensive control device that is commonly used can be used. Furthermore, the IN of this invention
In this case, since the robot and the workpiece are kept in the same positional relationship as when teaching is performed with both fixed, there is no need to perform teaching that takes into account pulsation of the conveyance device, etc. No special know-how is required, and since the robot moves in the same way as during teaching, accidents such as interference with peripheral equipment due to unexpected movements of the robot can be prevented.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing an example of a conventional machining facility using a robot, Fig. 2 is a schematic perspective view showing an embodiment of the present invention, Fig. 3 is a plan view thereof, and Fig. 4 is Shows coupler 1J'
A schematic diagram, FIG. 5, is a schematic diagram similar to FIG. 3 showing another embodiment of the present invention. 15- 10...Conveyor, 11...Dolly, 13...
Workpiece, 14... Fixed table, 15... Spring, 16... Robot moving device, 17... Welding robot, 19... Drive motor, 23... Control O device, 24...・Coupler, 26...Cylinder, 2
7... Bin, 29... Through hole, 30... Positioning plate, 31... Speed detection device, 34...
Detector, 38...11JIII device. Applicant 1 ~ Yota Jidosha Co., Ltd. Representative Patent Attorney Yutaka 1) Hisashi Take (and 1 other person) = 16-

Claims (1)

[Claims] In a processing device that processes a workpiece that is moved in a predetermined direction by a transfer device by operating the robot based on pre-stored data, a robot movement device that causes the robot to travel at approximately the same speed as the transfer device. is provided, and a trolley that is moved by the transport device is provided, and a fixing table for fixing the workpiece is moved in the traveling direction of the transport device by an elastic body disposed on at least one of the front end side and the rear end side. A robot characterized in that a coupler is disposed on the trolley so as to be movable and further connects and integrates the fixed base and the robot during processing, and is provided on either the fixed base or the robot. Processing equipment using