JPH0575537B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a system for preventing operational errors in an automobile assembly line.

(Prior art) In an assembly line in which predetermined assembly work is performed one after another while moving automobile bodies along the assembly line, tightening machines, etc. arranged along the line are used to properly perform the predetermined assembly work. JP-A-62-140726 already discloses a device that outputs a detection signal based on the work contents to indicate the occurrence of a malfunction when the work is not carried out.

However, with such a system that only issues an abnormality warning, in the case of an assembly line where carts are continuously transported, incorrect assembly may occur due to display malfunction or worker monitoring errors. The processed assembly is then transported to the next process, which poses serious problems in terms of quality control.

(Problems to be Solved by the Invention) The present invention has been made in view of these problems, and its purpose is to prevent problems from occurring on the main assembly line when an inconvenience occurs during assembly work. The purpose of the present invention is to propose a new device that immediately stops the subline without any problems and reliably prevents the occurrence of assemblies caused by incorrect work.

(Means for Solving the Problems) That is, the present invention, as a device for preventing erroneous work to solve such problems, provides a component mounting unit in a part of the path of the automobile body transport conveyor, and a stock conveyor is attached to this mounting unit. If the tightening machine with a torque control mechanism installed along the parts assembly conveyor generates a tightening torque that exceeds the set value on an assembly line where the parts assembly conveyor is connected through the The tightening machine and the parts assembly conveyor are stopped based on the value detection output.

(Example) An example of the present invention will be described below.

First, the assembly line applied to the malfunction prevention device of the present invention will be explained with reference to FIG. 2.The assembly line shown in FIG.
In other words, the small assembly conveyor is configured as a conveyor that conveys the jig pallet P integrated with the parts container C and assembles the rear suspension thereon, and is also laid parallel to the automobile body conveyor 16. Above, it is connected to the drive unit 15 so that the tact conveyance is carried out at a time interval that is the same as or shorter than the tact conveyance time interval of the conveyor 16. This small assembly conveyor 1 is equipped with a jig pallet P at the starting end of the small assembly conveyor 1.
A pallet input lifter 3 is disposed at the end of the lifter 3, and a stock conveyor is installed at the end of the lifter 3, which stores the jig pallets P that have been assembled and separated from the parts container, and sends them out in sequence to the next direction change device 4. Then, the stock conveyor 5 stores the jig pallets P whose direction has been changed by the direction changing device 4 and transports them in order to the component mounting unit 6, that is, the work mounting unit 6, directly below the automobile body transport line 16. It is arranged.

These conveyors 1, 3, and 5 are also constructed as an upper and lower two-stage conveyor with a pallet return conveyor (not shown) in the lower stage, and carry the empty jig pallet P after mounting the workpiece on the car body B.
A pallet return lifter 7 disposed between the stack conveyor 5 and the direction changing device 4 is configured to lower the pallet to the pallet return conveyor and return it to the pallet input lifter 2.

On the other hand, a container transport conveyor 9 installed on one side of the starting end of the small assembly conveyor 1 has a container lifter 10 at its starting end and a charging pusher unit 11 at its terminal end. Insert the parts container C into the pallet into the lifter 2.
It is configured to supply parts by connecting it to the upper jig pallet P. A container return conveyor 12 is also provided at the lower stage of the container transport conveyor 9, and extends from one side of the terminal end of the small assembly conveyor 1 to the container lifter 10. The empty parts container C is removed from the jig pallet P on the small assembly conveyor 1 by the unit 13, and then lowered onto the container return conveyor 12 by the container return lifter 14 and returned to the container lifter 10. It is configured as follows.

By the way, in the above-mentioned subassembly conveyor 1, a multi-axis or single-axis automatic tightening machine 20 equipped with a torque control mechanism is disposed at each component assembly station.

As shown in Fig. 1, these automatic tightening machines 20... are connected by a bus to a computer 21 dedicated to work management, and at the same time input torque management signals and other work command signals from this computer 21, 21 is configured to output a torque abnormal value signal and other work information signals.

This work management dedicated computer 21 is connected to the process control computer 22 of the assembly work area, which is connected to the entire system management computer 23, like the computers of other work areas, and is connected to the automatic tightening machine 20 based on the instructed vehicle type information. If, at the same time as outputting a work command signal, an abnormal value signal that is far from the torque control value is input from the automatic tightening machine 20, this will be displayed on the work area control panel 25, and the container lifter 10, container conveyor 9, loading pusher unit 11, pallet loading lifter 2,
Container return conveyor 12, small assembly conveyor 1, pallet return conveyor (not shown), and payout unit 13
and each drive motor that drives the container return lifter 14 is stopped, and furthermore, these conveyors etc. are restarted by a push button on the operation panel 24 that is operated upon completion of the subsequent confirmation work. has been done.

Next, the operation of this apparatus will be explained based on the flowchart shown in FIG.

When the parts container C carrying a set of rear suspension parts is loaded onto the container conveyor 9, and then pushed out by the loading pusher unit 11 toward the loading lifter 2 and connected to one side of the jig pallet 2, the small assembly conveyor 1 , the jig pallet P integrated with the component container C is sequentially transported to the next station and positioned there while being driven by the drive unit 15 at regular takt times. On the other hand, the automatic tightening machines 20 equipped with torque control mechanisms installed in these stations move according to the model information signal, and apply a constant torque to the parts that have been transferred and assembled onto the jig pallet P one after another. Secure by tightening the screws.

When the series of assembly steps is completed in this way and the jig pallet P integrated with the parts container C reaches the terminal end of the small assembly conveyor 1, the dispensing unit 13 disposed on the side of the jig pallet P integrated with the parts container C is removed from the jig pallet P, and then the container return lifter 14 lowers it onto the return conveyor 12 and returns it to the container return lifter 10. On the other hand, the stock conveyor 3 connected to the terminal end of the small assembly conveyor 1 stores the assembled jig pallets P on the conveyor 3 and sequentially sends them to the next direction change device 4, and then continues to the direction change device 4. The stock conveyor 5 stores the jig pallets P whose direction has been changed and sequentially transfers them to the workpiece mounting unit 6.
The assembled rear suspension is then lifted up and assembled to the lower part of the automobile body B transported by the overhead conveyor 16. The jig pallet P, which has been emptied after assembly, is lowered by the pallet return lifter 7 onto a lower return lifter (not shown), from which it is returned to the loading lifter 2 again.

By the way, during the above-described parts assembly process, if one of the automatic tightening machines 20 performs an abnormal tightening operation and outputs an abnormal value detection signal that deviates from the torque management value, this work area The work management computer 21 immediately displays the occurrence of an abnormality on the work area control panel 25, while
0. The drive motors that drive the container transport conveyor 9, input pusher unit 11, input lifter 2, container return conveyor 12, sub-assembly conveyor 1, pallet return conveyor, payout unit 13, and container return lifter 14 are stopped.

On the other hand, when the operator learns of the occurrence of an abnormality by stopping the conveyor and seeing the display, the operator immediately checks the relevant tightening machine 20 and, if there is a problem with the bolt supplied there, replaces it with another bolt. The manual button on the operation panel 24 is pressed to start the conveyor again via the work management computer.

During this troubleshooting period, the car body transport conveyor 16 continues to transport the car body B to the work mount unit 6 in a tactile manner, but the stock conveyor 3 from the end of the sub-assembly conveyor 1 to the work mount unit 6 , 5, there is a jig pallet 9, which has been transported by tact at a time interval shorter than the tact transport time interval of the automobile body transport conveyor, with the assembled rear suspension mounted thereon. Since the stock is stored, the assembly of the rear suspension to the automobile body B can be continued without any problem until the stock is exhausted.

(Effects) As described above, according to the present invention, the parts assembly conveyor is connected to the parts mounting unit provided in the route of the automobile body conveyor via the stock conveyor, and this assembly conveyor and Since the tightening machine with a torque control mechanism installed along the conveyor is stopped based on the detection output of abnormal tightening torque, the flow of parts with assembly defects can be stopped by stopping the conveyor and quality can be improved. At the same time, by stocking parts with the stock conveyor, the automobile body transport conveyor can be operated continuously without stopping even during the removal process after the occurrence of a tightening defect. .

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a control mechanism of a small assembly conveyor system configured to apply the device of the present invention;
This figure shows the entire assembly line, and FIG. 3 shows its operation flowchart. 1...Small assembly conveyor, 2...Pallet input lifter, 3, 5...Stock conveyor, 6...Work mount unit, 7...Pallet return lifter,
9... Container transport conveyor, 10... Container input lifter, 12... Container return conveyor, 16... Car body transport conveyor, 20... Tightening machine with torque control mechanism.

Claims (1)

[Scope of Claims] 1. An assembly line in which a parts mounting unit is disposed in a part of the path of an automobile body conveyor, and a parts assembly conveyor is connected to the mounting unit via a stock conveyor. A tightening machine equipped with an abnormal torque value detection means is arranged along the parts assembly conveyor, and the tightening machine and the parts assembly conveyor are stopped based on the abnormal value detection output from the tightening machine. A device for preventing incorrect work on an assembly line, characterized in that it is equipped with a control means. 2. Claim 1 characterized in that the tact conveyance time interval of the parts assembly conveyor is shorter than the tact conveyance time interval of the automobile body conveyor.
A device to prevent errors in the assembly line described above.