JPH03137965A - Automatic painting method - Google Patents

Abstract

PURPOSE:To accurately paint the entire surface of an object to be painted by detecting the shift of the position of the object to be painted with respect to a hanger to correct the injection period of a spray gun. CONSTITUTION:The front edge (b) of a fed object (a) to be painted is detected by an object sensor 5 and, subsequently, a hanger 2 is detected by a hanger detecting sensor 4 and the respective detection signals of both sensors are inputted to an operation part 8 while the distance from the hanger 2 to the front edge (b) of the object (a) to be painted is operated on the basis of the input time difference of both detection signals in the operation part 8 and, after a definite time is elapsed from the point of time when the hanger 2 is detected by the hanger detecting sensor 4, paint is injected from a spray gun 7 to perform painting. That is, since the injection start period of the paint is changed corresponding to the distance from the hanger 2 to the front edge of the object (a) to be painted, even when there is shift between the object (a) and the hanger 2, the object (a) to be painted can be accurately painted.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Application Needle The present invention conveys a workpiece by hanging a hanger on a conveyor running in one direction and hooking the workpiece, and detects the position of the workpiece using the hanger. This invention relates to an improvement in an automatic painting method in which paint is sprayed from a spray gun.

Problems to be Solved by the Prior Art and the Invention In such an automatic painting method, after a certain period of time has elapsed after the passage of the hanger is detected by a phototube or a limit switch, the front edge of the object to be coated in the transport direction is located in front of the spray gun. It was supposed to start spraying paint when it judged that it had reached this point.
It is difficult to suspend the object to be coated at a constant position relative to the object, and it is unavoidable that some misalignment will occur. However, if the deviation becomes large, uncoated parts are left on the object to be coated, and there is a drawback that repair coating must be performed manually.

Means for Solving the Problems In the present invention, as a means for solving the above problems, the misalignment of the object to be coated with respect to the hanger is detected and the injection timing of the spray gun is corrected.

Functions and Effects of the Invention The present invention has the above-mentioned configuration, and since the injection timing of the spray gun is adjusted according to the position of the object to be coated with respect to the hanger, it is possible to avoid misalignment of the object to be coated with respect to the hanger. Also, when the object to be coated is conveyed to the front of the spray gun, the paint is sprayed and the entire surface of the object to be coated can be accurately coated.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings.

In the figure, l is a conveyor that runs at a constant speed in the arrow direction, and a large number of hangers 2 are suspended from this conveyor at regular intervals. Each hanger 2 has a hook part (not shown) on which a coated object a is pulled. It is designed to be hung and transported. A sensor stand 3 and a reciprocator 6 are located near the conveyor l.
are placed upright at intervals in the transport direction, a hanger detection sensor 4 is mounted on the upper end of the sensor stand 3, a workpiece detection sensor 5 is mounted on the middle part, and a reciprocator 6 is mounted. An attachment rod 1O is connected to the endless chain 9 that runs in circulation, and a spray gun 7 is attached to this so that it moves up and down as the endless chain 9 runs. Detection signals from each sensor 4.5 are input to a calculation section 8, and the calculation results are input to a control section (not shown) of the reciprocator, so that spraying and stopping of paint from the spray gun 7 is controlled.

In this embodiment, the leading edge of the workpiece a being conveyed is detected by the workpiece sensor 5, and then the hanger 2 is detected by the hanger detection sensor 4, and the respective detection signals are input to the calculation section 8. Then, the distance between the hanger 2 and the front edge of the object to be coated a is calculated based on the input time difference between both detection signals in the calculation unit 8, and the spray gun 7 is activated after a certain period of time has elapsed since the hanger 2 was detected by the hanger detection sensor 4. The paint is sprayed from the hanger 2 and the front edge of the coated object a, and the timing of starting the spraying of the paint is changed depending on the distance between the front edge of the coated object a and the hanger 2. Even if there is a deviation between the two, the object to be coated can be coated correctly.

In this embodiment, the spray gun is driven by a reciprocator, but it may also be driven in three-dimensional directions by a robot.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an outline of an embodiment of the present invention.

Claims (1)

[Claims] In an automatic coating method, the object to be coated is transported by hanging a hanger on a conveyor running in one direction, and the position of the object to be coated is detected by the hanger and paint is sprayed from a spray gun, An automatic painting method characterized in that the injection timing of the spray gun is corrected by detecting a positional shift of the object to be coated with respect to the hanger.