JPH03270834A - Parts mounting device control method - Google Patents

Abstract

PURPOSE:To prevent generation of line stop by providing a sufficient margin in the fastening place of each piece of components with an abject for installation, arranging a socket at the tip of a nut runner so as to be floating, and setting the piece of components according to the teaching data in the event of failure in the sensing or computation. CONSTITUTION:When a position sensor 5 or a computer is judged to be in failure according to the operation checking signal, robot controllers 71, 72 actuate robots 2, 3, 4 to install a front fender (b) and door (c) to a car body (a) in the setting position in conformity to the teaching data. If therein the holddown hole is formed large in advance with a likely dislocation amount of screw hole taken in account, the screw hole well face a part of the holddown hole, and fastening bolt can be driven into the screw hole through the holddown hole by means of the floating motion of a socket at the tips of nut runners 61, 62. When mounting is completed, the robots 2, 3, 4 return to their original positions, and an operation end signal is sent to a sequencer from the robot controllers 71, 72. Now the car body (a) is placed out of the install station, and information is sent to a management device so that the components installed undergo necessary correction in a later process.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention involves setting parts such as doors on an object to be assembled, such as an automobile body, using an assembly robot or a separately installed fastener. The present invention relates to a method of controlling a parts assembling device in which parts are fastened to an object to be assembled using a nut runner mounted on a robot/soto.

(Prior art) Conventionally, as an assembly device for automobile doors, Japanese Patent Application Laid-Open No. 61-4
According to Publication No. 6780, position information such as positional deviation of the automobile body is detected by a detection means, teaching data regarding the door set position is corrected by a calculation means based on this position information, and this correction data is used by an assembly robot. It is known to transmit correction data to a robot controller and use an assembly robot to set the door at a set position according to the correction data.

(Problem to be Solved by the Invention) In the above system, if the correction data is incorrect due to an abnormality in the detection means or calculation means, the door will not be set correctly on the car body, and the mounting hole for the door hinge on the car body will be on the side of the car body. If the door hinge becomes misaligned with the screw hole, it becomes impossible to fasten the door hinge to the vehicle body, resulting in line stops each time, resulting in poor productivity.

Incidentally, recently, the positioning accuracy of the vehicle body has been improved, and it is now possible to correct the set position of parts with respect to the vehicle body within a limited range of about several millimeters.

The present invention has focused on this point, and has as an object to provide a control method for a parts assembly device that can prevent line stops caused by abnormalities in detection means or calculation means as much as possible. There is.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, parts are set on an object to be assembled using an assembly robot, and mounted on the assembly robot or a separate tightening robot. A control method for a parts assembly device in which a part is fastened to an object to be assembled using a nut runner, the method includes teaching regarding the set position of the component by a calculation means based on position information of the object to be assembled detected by a detection means. In a device that corrects data, sends this correction data to the robot controller of the assembly robot, and sets the parts at the set position according to the correction data,
The connection point between the part and the object to be assembled is formed with a margin so that the part can be fastened to the object to be assembled even if the part is misaligned with respect to the object to be assembled, and the tip of the nut runner is The socket is made freely floating, and when an abnormality occurs in the detection means or the calculation means, the parts are set at the setting position according to the teaching data.

In addition, typical examples of methods for fastening parts to objects to be assembled include:
There are two methods: inserting a tightening bolt into a mounting hole formed on one side of the component and the object to be assembled, and tightening it into a counterbore formed on the other; There is a method of inserting the bolt into the mounting hole that has been formed and tightening a nut onto this bolt. In these fastening methods, forming the fastening points between the parts and the objects to be assembled with a margin as described above means forming the mounting hole into a large-diameter hole that allows the bolt to be inserted with a margin. do.

(Function) The details of the present invention will be explained by taking as an example a case in which a tightening bolt is inserted into a mounting hole formed in the part and tightened into a threaded hole formed in the object to be assembled as a part fastening method. explain.

If the parts are set in the set position according to the teaching data, if there is a misalignment of the part to be assembled or an error in assembly accuracy, the mounting hole of the part will be misaligned with the tapped hole of the assembly. By forming the mounting hole as a large diameter hole, the screw hole faces any part of the mounting hole. In this case, the axis of the nut runner is also eccentric with respect to the screw hole, but since the socket at the tip of the nut runner can float freely, the tightening bolt held by the socket can be tightened into the screw hole by the floating action of the socket.

On the other hand, if an error occurs in the correction data due to an abnormality in the detection means or calculation means, and the parts are set at the set position according to this correction data, the cumulative error of the deviation of the assembled object and the error in the correction data will cause In some cases, parts are set in a position where the screw holes come out of the mounting holes, making it impossible to fasten the parts to the object to be assembled.

However, in the present invention, when an abnormality occurs in the detection means or calculation means, the correction data is invalidated and the parts are set in the set position according to the teaching data. The tightening bolt is tightened into the screw hole by the floating action of the socket of the nut runner.
Although the parts are misaligned with respect to the object to be assembled, it is possible to assemble the parts, and line stops do not occur.

Note that the positions of parts assembled when an abnormality occurs will be corrected in a subsequent process.

(Embodiment) The illustrated embodiment shows an assembly device for assembling a front fender b and a door C to an automobile body a, which is an object to be assembled. (1
) (1) Above, as shown in Fig. 1, a first assembly robot (2) for the front fender, a second assembly robot (3) for the door, and both assembly robots (2) (3 ) is installed, and the front fender b and door C are set on the vehicle body a by the assembly robots (2) and (3), and the assembly station is further equipped with a door tightening robot (4) located in the middle of , a plurality of position sensors (5) are arranged to detect the positions of the bulkhead of the vehicle body a and the front and back two locations on each left and right side of the vehicle body a,
The position information from these sensors (5) is used to correct the set positions of the front fender b and door C relative to the vehicle body a. The multi-position sensor (5) was movable between a predetermined detection position and a retracted position using a suitable moving mechanism.

Each of the robots (2) (3) (4) has a first slide stand (2a) (8a) (4a) provided on a base (1) so as to be movable back and forth, as shown in FIGS. 1 and 2. ) The second slide table (2b) (3b) (
4b) and the second slide stand (2b) (3b)
(4b) is a vertically movable lifting frame (2c) (3c)
(4c) shall be constructed of an orthogonal coordinate type robot, and each assembly robot (2) and (3) will have a
c) Jig (2e) (3e) that holds the front fender b and door C on (Be) via the wrists (2d) (ad)
The lifting frame (4C) of the tightening robot (4> is equipped with a nut runner (61) for fastening the door hinge to the vehicle body a, and the jig (2e) of the first assembly robot (2) is equipped with the following:
A nut runner (62) is installed to fasten the flange portion of the upper edge of the front fender b to the vehicle body a.

As shown in Fig. 3, each nut runner (61) (62) is mounted by forming a tightening bolt d, which is attracted and held by a magnet (6b) into a socket (6a) at the tip, on the flange of a door hinge or front fender b. It functions to be screwed into a screw hole on the vehicle body side through hole e, and the rotating shaft of the nut runner is configured with an inner and outer double structure consisting of a sleeve sleeve (6c) and a square shaft (6d) inside, and a socket (6a). At the enlarged part (6e) formed at the tail end of the shaft, the cylinder shaft (6c>
There is a gap in the hole so that it can be inserted freely, and the ampullae (6e) is always inserted.
is fitted into the centering guide (6g) attached to the tip of the cylindrical shaft (6c) with the biasing force of the spring (6r), and the socket (6a
) in the neutral position, and the enlarged part (6e) and the spring (6r
) When pushed into the cylinder shaft (6C) against the
6a) is released from the constraint by the centering guide (6g) and is allowed to float. The square shaft (6d) has an ampulla (6d) so as not to inhibit this floating motion.
It engages with the square hole formed in 6e) with a clearance.

The mounting hole e is formed into a large-diameter hole through which the tightening bolt d can be inserted with ample margin, and the tip of the tightening bolt d is formed in a tapered shape, so that the mounting hole e is not large enough to accommodate the threaded hole. Even if e is misaligned, as long as the screw hole faces into the mounting hole e,
As the nut runner moves forward, the tip of the tightening bolt d is inserted into the screw hole by the guiding action of its taper, and then the socket (
6a) operates in a floating manner, and the tightening bolt d is securely tightened into the screw hole.

The first assembly robot (2) is controlled by a first robot controller (71), and the second assembly robot (3) and tightening robot (4) are controlled by a second robot controller (72). , as shown in Fig. 4, the signals are dispersed between each robot controller (71) (7□), the sequencer (8), and the computer (9) that manually inputs the signals from the position sensor (5). The parts were assembled according to the procedure shown in FIG.

To explain this below, when the vehicle body a is set at the assembly station (■), a start signal is sent from the sequencer (8) to each robot controller (L) (72) (■), and each robot Controller (71) (7□
) Each robot (2) (3) (4) moves to the parts receiving position according to the teaching data input to Assembly robot (
2) At the same time as (3) receives the bolt, the tightening bolt d is set in the nut runner (6□) of the tightening robot (4) and the nut runner (62) of the first assembly robot (2) (■■), and then the car body Each robot (2) (3) (4
) moves (■).

Furthermore, after the output of the start signal, the position sensor (5) moves to the detection position (■), and when it arrives at the detection position, an arrival signal is sent from the sequencer (8) to the computer (9) (■). When arrival at the detection position of the position sensor (5) is confirmed by the signal (■), the computer (9) reads the position information of the vehicle a detected by the position sensor (5) (■), and the reading is completed. By the way, computer (9)
A read completion signal is sent to the sequencer (8), and the position sensor (5) returns to the retracted position (phase 0).
On the other hand, the computer (9) checks whether the read position information contains unusual information and sends it to the position sensor (5).
0), and if it is normal, use the read position information to determine the misalignment of the set position of the vehicle body a, the mounting position of the side panel, etc., and adjust the position of the front fender b and door C relative to the vehicle body a. Correction data for correcting the set position according to this deviation is calculated and created (0), and then a calculation completion signal is sent from the computer (9) to the sequencer (8) (1).

When the position sensor (5) is determined to be abnormal in step (2), an abnormality signal is sent from the computer (9) to the sequencer (8) (0), and also when an abnormality occurs in the computer (9). An abnormality signal is sent to the sequencer (8>), and the sequencer (8> checks whether the calculation of correction data has been performed normally or whether an abnormality has occurred in the position sensor (5) or computer (9)). Then, when each robot (2) (3) (4) arrives at the position one step before the assembly position as described above, the sequencer responds to the signal from each robot controller (L) (7□). - (8) to each robot controller (L)
An operation confirmation signal is sent to (72) to determine whether it is normal or not (Q
) Each robot controller (L) (72) determines whether it is normal or not based on the operation confirmation signal [Co., Ltd.]), and if it is normal, each robot controller (71) (7□)
A correction data read signal is transmitted from the computer (9) to the computer (9), and the correction data corresponding to each robot controller rough 7, ) (7□), that is, the first
Robot controller (7,) for assembly robot (2)
The correction data for the set position of front fender b and the robot controller (A □
) is sent correction data for the set position of door C (@
@), each assembly robot (2) and (3) operates from the above-mentioned front position according to this correction data, and the front fender b and door C are respectively set correctly on the vehicle body a according to the correction data, and the front fender b and the door C are placed above the front fender b. The flange on the edge is attached to the nut runner (6) mounted on the first assembly robot (2).
□) is fastened to the car body a, and the tightening robot (
4> is moved to a predetermined tightening position according to the correction data, the door hinge is fastened to the vehicle body a by the nut runner (6□) mounted thereon, and the parts are assembled (@
).

On the other hand, if an abnormality is determined in the step [stock], the teaching data regarding the set position of the parts input to each robot controller (71) (7□) is read out, and each robot (2) ( 3) Operate (4) according to the teaching data, operate the front fender b and door C according to the teaching data, and assemble the front fender b and door C to the vehicle body a at the set positions according to the teaching data. On this occasion,
The mounting hole e formed on the flange part of the front fender b or the door hinge may sometimes misalign with the tapped hole on the vehicle body side, but recently, with improvements in positioning accuracy and assembly accuracy of the vehicle body a, the amount of misalignment of the screw hole has been reduced. It is designed to stay within a certain range, and if the mounting hole e is made larger considering this amount of deviation, the tapped hole will face any part of the mounting hole e, and the nut runner (6+) (62) Tip socket (6a>
Due to the floating action of , the tightening bolt d is tightened as described above.
It can be screwed into the screw hole through the mounting hole e. still,
Although not shown, parts are assembled according to the teaching data even when a correction data communication error occurs.

When the assembly is completed as described above, each robot (2)
(3) (4) should be returned to its original position @), and each robot controller (71) (72,) is connected to the sequencer (
A work completion signal is sent to step 8) ([phase]), and when the work of all robots is completed, the vehicle body a is taken out from the assembly station ([phase]@).

Note that it is necessary to correct the position of the parts assembled when an abnormality occurs in a subsequent process, and therefore, when an abnormality occurs, the information is sent to an external management device.

(Effects of the Invention) As is clear from the above description, according to the present invention, the parts and the objects to be assembled are provided with a margin at the fastening points, and the socket at the tip of the nut runner is made floating. Within the normal deviation range of the assembly, the parts can be fastened to the object to be assembled at the set position according to the teaching data, and if an abnormality occurs in the detection means or calculation means, the set position according to the teaching data should be set. Since the parts are set in the correct position, the parts can be assembled even if they are deviated from the normal position on the object to be assembled, and the frequency of line stops caused by abnormalities in the detection means or calculation means can be reduced. It has the effect of improving productivity by reducing

[Brief explanation of drawings]

Fig. 1 is a plan view of an example of a parts assembling device to which the method of the present invention is applied, Fig. 2 is a front view seen from the ■-■ arrow in Fig. 1, and Fig. 3 is a sectional view of the tip of the nut runner. 4 is a block circuit diagram of the control system of the tightening device, and FIG. 5 is a flowchart showing the procedure for assembling parts. a... Vehicle body (object to be assembled) b... Front fender (parts) C... Door (parts) (2) (3)
...Assembling robot (4)...Tightening port bot (
5)...Position sensor (detection means) (61) (62)
...Nuttranna <6a>...Socket (
71) (7□)...Robot controller (9)・
...Computer (computing means) patent applicant
3 people outside Honda Motor Co., Ltd. Figure 3 Figure 4

Claims (1)

[Claims] Control of a parts assembly device in which parts are set on an object to be assembled using an assembly robot, and the parts are fastened to the object by a nut runner mounted on the assembly robot or a separately installed tightening robot. The method comprises: correcting teaching data regarding the set position of the parts by a calculation means based on position information of the object to be assembled detected by the detection means; and transmitting this correction data to a robot controller of an assembly robot. When parts are set in the set position according to correction data, the fastening points between the parts and the to-be-assembled parts are set so that the parts can be fastened to the to-be-assembled object even if the parts are misaligned with respect to the to-be-assembled object. In addition, the socket at the tip of the nut runner is made to be freely floating, and when an abnormality occurs in the detection means or the calculation means, the part is placed in the set position according to the teaching data. A control method for a parts assembly device, characterized in that the parts assembly device is set.