JP2907394B2 - Automatic coating method and equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of suspending an object to be coated on a conveyor at regular intervals and sequentially transporting the object to be coated. The present invention relates to an automatic painting method for spraying paint in a spray pattern corresponding to a shape to apply painting, and an apparatus used for carrying out the method, and particularly to a painting surface even when a suspended position of an object to be painted is shifted. The present invention relates to an automatic coating method and apparatus capable of accurately applying coating to the entire surface.

Conventional technology Conventionally, when a large number of objects to be coated having the same shape are coated, the objects to be coated are hung on a conveyor with a hanger at regular intervals, and sequentially placed at a coating position where a spray gun operated by a reciprocator or a robot is installed. Each time the object comes to the coating position, the spraying and stopping of the paint from the spray gun is controlled based on a predetermined pattern signal, and the spray pattern corresponding to the coating surface shape of the object to be coated is controlled. Automatic spraying that repeats squirting of the paint is performed.

Problems to be Solved by the Invention By the way, when performing such automatic painting, for example,
If the hanger used is bent or has a dimensional error, the suspended position of the workpiece will shift,
Since the position of the spray pattern is always constant, the position of the spray pattern does not match the painted surface of the workpiece,
Coating defects such as uncoated parts occur. To avoid this, the spray pattern may be preliminarily widened, but this has the disadvantage of wasting paint.

Means for Solving the Problems As means for solving the above-described problems, the automatic coating method of the present invention recognizes the shape of the coating surface of the object to be coated on a predetermined coordinate plane before the coating position and determines the center of gravity of the coating surface. , And the coordinates of the center of gravity are compared with the coordinates of the reference center of gravity corresponding to the case where the object to be coated is at the reference hanging position, and the position of the spray pattern is corrected based on the comparison result.

Further, the automatic coating apparatus of the present invention is a shape recognition unit that recognizes the shape by photographing the shape of the coating surface of the object to be coated at a detection position provided before the coating position and forming an image on a certain coordinate plane. A coordinate calculation unit for calculating the coordinates of the center of gravity of the recognized shape; a storage unit for storing in advance the coordinates of the center of gravity of the recognized shape when the object to be coated is at the reference hanging position; A difference calculation unit for calculating a difference from the barycentric coordinates and a pattern correction unit for correcting the position of the spray pattern based on the calculation result are provided.

Operation and Effect of the Invention The method of the present invention has the above-described configuration, and when the object to be coated comes before the coating position, the shape of the coating surface is recognized on a fixed coordinate plane, and the coordinates of the center of gravity are obtained. The center-of-gravity coordinates obtained are compared with the reference center-of-gravity coordinates corresponding to the case where the object to be coated is at the reference hanging position, whereby a shift in the suspended position of the object to be coated is detected. Based on the position of the spray pattern is corrected to compensate for the positional deviation, when the object to be coated is transported to the coating position,
The paint is ejected in a spray pattern in which the positional relationship with the coating surface of the article to be coated corresponds exactly.

In this way, even if there is a shift in the suspended position of the object to be coated, the position is automatically corrected so that the spray pattern compensates for the position shift, and the position exactly matches the position of the object to be coated. Therefore, the coating can be reliably applied to the entire surface of the object to be coated without wasteful consumption of the coating material. Further, since the coordinates of the center of gravity of the painted surface shape are used to detect the positional deviation, there is an effect that the present invention can be applied to painting of any object which is not limited to the painted surface shape.

Further, the apparatus of the present invention has an effect that the above-described method of the present invention can be reliably performed.

An embodiment of the apparatus of the present invention will be described below with reference to the accompanying drawings, and an embodiment of the method of the present invention will be clarified by describing its operation.

In FIG. 1, reference numeral 1 denotes a conveyor which travels in a horizontal direction, on which an object to be coated a is hung at a fixed interval by a hanger 2 and conveyed in the direction of the arrow. ing. A painting robot 3 having a spray gun 4 reciprocally driven up and down by a reciprocator 5 is installed at a painting position A provided on the side of the conveyor 1, and from a pattern setting unit 8 described later in detail. The spray gun controller 7 controls the spraying and stopping of the paint from the spray gun 4 on the basis of the above signal, so that the paint is sprayed in a predetermined spray pattern.

At a detection position B which is separated from the above-mentioned painting position A by a certain distance to the near side in the transport direction, a camera 10 for photographing the front shape which is the painting surface of the workpiece a is installed. As shown in (2), the image is formed on the XY two-axis coordinate plane P so that the front shape can be recognized. This shape recognition unit 11 is connected to the pattern setting unit 8 described above,
Based on the recognized shape first recognized by the shape recognition unit 11,
A pattern signal serving as a reference is set in the pattern setting unit 8, and is not output to the pattern setting unit 8 from the second time.

The other output side of the shape recognition unit 11 is connected to a coordinate calculation unit 12 that calculates coordinates of the center of gravity of the shape recognized by the shape recognition unit 11. The coordinate calculating unit 12 is connected to a storage unit 13 which takes in the barycentric coordinates calculated first and stores them as reference barycentric coordinates. Coordinate calculator 12
And a storage unit 13 are connected to a difference calculation unit 14. The second and subsequent barycentric coordinates calculated by the coordinate calculation unit 12 are output to the difference calculation unit 14, and each time the barycenter coordinates are input, the storage unit The reference barycentric coordinates are called from 13 to calculate the difference between the two barycentric coordinates. A pattern correction unit 15 is connected to the difference calculation unit 14, and based on the difference signal of the difference calculation unit 14, the pattern setting unit 8 described above is shifted by the amount corresponding to the displacement of the barycentric coordinates.
The reference pattern signal set in is corrected.

 Next, the operation will be described.

When the first workpiece a is transported to the detection position B, the camera
The front shape is photographed at 10, and the shape F is imaged on the coordinate plane P as shown by the solid line in FIG. And
A reference pattern signal is set in the pattern setting unit 8 corresponding to the shape F. At the same time, the coordinate calculation unit
The coordinates (X, Y) of the center of gravity O of the shape F are calculated by 12 and stored in the storage unit 13 as the reference center of gravity coordinates. When the object a reaches the coating position A, the spraying and stopping of the spray gun 4 is controlled based on the reference pattern signal, and the coating is performed in a spray pattern corresponding to the front shape of the object a. Done.

For the second and subsequent objects to be coated a, the front shape is similarly imaged on the coordinate plane P and the coordinates of the center of gravity are obtained each time the detection position B is reached. It is compared with the reference barycentric coordinates. If the two coordinates match, the output from the difference calculation unit 14 is 0,
No correction of the pattern signal is performed assuming that there is no shift in the suspended position of the splay position, and the spray pattern is maintained at the initial reference position.

Due to the hanger 2 being bent, the object to be coated a
Of the suspension position is shifted, when the photographed front shape is imaged on the coordinate plane P, its position as shown in the shape F ₁ of the chain line in FIG. 2 is displaced, the center of gravity O ₁ The coordinates (X ₁ , Y ₁ ) also shift. Therefore, a difference signal corresponding to the difference between the reference barycentric coordinates (X, Y) and X ₁ −X and Y ₁ −Y is output from the difference calculation unit 14, and the pattern setting unit 8 is output by the pattern correction unit 15.
Is corrected so as to shift the position in the X and Y directions by the difference, and
Comes to the painting position A, the paint is ejected in a spray pattern whose positional relationship with the front exactly corresponds.

When the coating of the object a is completed, the pattern signal returns to the reference position again, and thereafter, the same operation as described above is repeated.

As a result, all the objects to be coated a are accurately coated over the entire front surface.

In the above embodiment, the reference pattern signal and the barycentric coordinates are set based on the recognition signal of the front shape of the first object to be coated a, but these are input in advance by another means. Is also good.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the apparatus of the present invention, and FIG. 2 is an explanatory diagram of a shape recognition portion of the object to be coated. a: Workpiece, A: Painting position, B: Detection position, 1: Conveyor, 2: Hanger, 4: Spray gun, 7: Spray gun control unit, 8: Pattern setting unit, 10: Camera, 11: Shape recognition Section, 12: coordinate calculation section, 13: storage section, 14: difference calculation section, 15: pattern correction section,
F, F ₁ : recognition shape, O, O ₁ : center of gravity, P: coordinate plane

Claims (2)

(57) [Claims] An object to be coated is suspended on a conveyor at a predetermined interval and transported sequentially, and each time the object is transported to a coating position, paint is ejected in a spray pattern corresponding to the shape of the coating surface. In the automatic coating method in which the coating is performed, the shape of the coating surface of the object to be coated is recognized on a fixed coordinate plane in front of the coating position, and the coordinates of the center of gravity are obtained. An automatic coating method, comprising comparing with a reference barycentric coordinate corresponding to a reference hanging position, and correcting the position of a spray pattern based on the comparison result. 2. An object to be coated is hung on a conveyor at a predetermined interval, and is conveyed in sequence, and every time the object is conveyed to a coating position, a paint is ejected in a spray pattern corresponding to the shape of the coated surface. In an automatic coating device that performs coating by applying a paint, a shape that recognizes the shape by photographing the shape of the coating surface of the workpiece at a detection position provided before the coating position and forming an image on a certain coordinate plane A recognition unit, a coordinate calculation unit that calculates the coordinates of the center of gravity of the recognized shape, a storage unit that stores in advance the coordinates of the center of gravity of the recognized shape when the object to be coated is at the reference hanging position, and the reference center of gravity coordinates An automatic coating apparatus, comprising: a difference calculation unit that calculates a difference between the calculated position and the detected barycentric coordinates; and a pattern correction unit that corrects the position of the spray pattern based on the calculation result.