JPH044077A - Method for coating inside surface of box-shaped material to be coated - Google Patents

Abstract

PURPOSE:To coat the inside surfaces of a box-shaped material to be coated with a uniform film thickness over the entire surface thereof by inserting nozzles into the material to be coated and ejecting coating materials while rotating the material to be coated around the nozzles. CONSTITUTION:After the material X to be coated is cramped in a chuck 1 in a horizontal posture opened to the front surface, the material X to be coated is lifted up to a coating position A; in succession, the coating materials are ejected from the nozzles 5 while the material X to be coated is rotated around the shaft 3 of the chuck 1 by rotationally driving the shaft 3. The coating material ejected from the nozzle 5 facing the front is then deposited on the inside base of the material X to be coated and the coating materials ejected from two pieces of the nozzles 5 are deposited on the inner side faces. The ejected coating material particles partly suspend in the material X to be coated and fall by the influence of gravity, but the material X to be coated is kept rotated and the respective inner side faces rotate successively to the lower side; therefore, the falling coating material particles are eventually deposited on all of the inner side faces and the nonuniformity of the coating amt. is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a coating method suitable for coating the inner surface of a box-shaped object.

Problems to be Solved by the Prior Art and the Invention Conventionally, when painting the inner surface of a box-shaped object, the object is held in a horizontal position with an opening in the front, and a paint spouting device is placed inside the object. It is common to insert a nozzle to apply the paint. In this case, depending on the shape of the object to be coated, for example, if the object is deep, the nozzle may be moved backwards, or if the object is large, multiple nozzles may be placed facing forward and sideways. A method is adopted in which paint is jetted out while rotating the objects, but in either case, the object to be coated remains held in a fixed position.

By the way, all of the paint particles ejected from the nozzle are not immediately applied to the inner surface of the object to be coated, but some of them float inside the object and fall under the influence of gravity. As mentioned above, since the object to be coated is held in a fixed position, the falling paint particles mainly adhere to the inner surface located on the lower side, and the film thickness on the lower inner surface increases accordingly. It has the disadvantage that it is larger than the other inner surfaces, making it impossible to obtain a uniform painted surface.

Means for Solving the Problems As a means for solving the above-mentioned problems, the method for painting the inner surface of a box-shaped object of the present invention includes the following steps: A nozzle for spraying paint directed toward the inner surface of the object to be coated was inserted, and the paint was jetted from the nozzle while rotating the object to be coated around the nozzle.

Functions and Effects of the Invention The present invention has the above-described structure, and since the object to be coated is rotated, even if the paint particles ejected from the nozzle and suspended in the object to be coated fall due to gravity, the paint particles will not be removed. The paint is applied to all the inner surfaces of the object to be coated as it moves downward one after another, eliminating imbalances in the amount of paint applied and ensuring a uniform film thickness over the entire inner surface of the object. It has the effect of being able to be painted.

EXAMPLE Hereinafter, an example of the method of the present invention will be described with reference to FIG.

In the figure, l is a chuck that holds a box-shaped object to be coated It reciprocates with the WB and can rotate around the shaft 3 by rotationally driving the shaft 3. At the above-mentioned coating position A, a coating machine 6 having a nozzle 5 facing forward and nozzles 5 facing on both sides at right angles to the coating machine 6 is installed concentrically with the axis 3 of the chuck ■.
The nozzle 5 reciprocates between a forward position where it is inserted into the object X as shown by a solid line and a retreated position where it is retracted outside the object X as shown by a chain line.

When painting, at attachment/detachment position B, the object to be coated The nozzle 5 of the coating machine 6, which has been retracted to the position, is inserted into the object to be coated. And the axis 3 of chuck l
When the paint is ejected from the nozzle 5 while rotating the workpiece X around its axis 3, the paint ejected from the nozzle 5 facing forward hits the inner bottom surface of the workpiece X and the sides. The paint sprayed from the two nozzles 5 facing the same direction is applied to the inner surface. During this time, some of the ejected paint particles float inside the object X and fall under the influence of gravity, but since the object X is rotating and each inner surface turns downward one after another, The falling paint particles will coat all the inside surfaces,
The imbalance in coating amount is resolved.

After a certain amount of coating time has elapsed, the spraying of paint is stopped, the nozzle 5 is moved back to the outside of the object to be coated, and the chuck l is
The rotation of the shaft 3 is stopped, and the object to be coated X is lowered to the attachment/detachment position B and removed from the chuck I.

Then, by holding the next object to be coated X in the chuck L and repeating the above operation, the same coating will be performed.

In addition, when painting in the above embodiment, if the nozzle 5 is rotated around the axis of the coating machine 6 in the direction opposite to the object X as shown by the chain arrow in the figure, the coating will be more uniform. be able to.

Further, the present invention can be similarly applied to a painting method in which only one forward-facing nozzle is inserted into the object to be coated, and paint is ejected while the nozzle is moved backward.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view for explaining one embodiment of the present invention. X: Object to be coated l: Chuck 2 Nireshi locator 3:
Axis 5: Nozzle 6: Painter

Claims (1)

[Claims] Inside the box-shaped object to be coated, which has an open front and a horizontal position,
An inner surface of a box-shaped object to be coated, characterized in that a nozzle for ejecting paint directed toward the inner surface of the object to be coated is inserted, and paint is ejected from the nozzle while rotating the object to be coated around the nozzle. Painting method