JPH0632776B2 - Coating method for the outer surface of steel pipe sheet piles - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a spray coating method for moving steel pipe sheet piles back and forth,
This relates to a method for setting a fixed circumferential position of a steel pipe sheet pile during initial and continuous operation and painting the outer surface of the steel pipe sheet pile.

(Prior art and problem to be solved by the invention) In a method of spray painting a steel pipe sheet pile by moving it back and forth,
In the conventional method of painting the outer surface of a steel pipe sheet pile, an operator enters a painting booth 9 shown in Figure 4 and visually checks the fixed position of the steel pipe sheet pile 1 so that the spray pattern 7 discharged from the spray gun 6 satisfies the painting direction of the painting pattern shown in Figure 5 and the appropriate lap allowance 10 shown in Figure 6. If there is a problem with the fixed painting position, the operator performs an inching operation on the rotary drive body 3 and moves the spray gun 6 up and down using the swivel joint 5.

In the conventional coating method disclosed in Japanese Patent Laid-Open No. 61-178057, which combines a means for detecting the position of the object to be coated with a function for correcting the relative position of the robot, the position detection means is affected by the adverse environment inside the coating booth, making it difficult to maintain, and the function for correcting the relative position of the robot has the problem of being unable to perform absolute angle correction.

However, when the paint position is set by the operator's sense, it is difficult to determine a fixed position and reproducibility is not possible. This has the effect of causing uneven film thickness due to multiple coats, leading to increased costs. In particular, there are recent user needs that require the same film thickness level around the nail as around the mother pipe, which is difficult to meet with conventional methods. In addition, the work environment is inside a paint booth, so the work is carried out in a harsh environment where paint mist is rampant,
Therefore, sensor and image processing methods have been considered as methods of painting without requiring an operator to enter the painting booth, but the contact sensor method can cause scratches on the paint film, and the non-contact sensor and image processing methods can cause paint mist to adhere to the equipment in the painting environment, resulting in large equipment, investment, and maintenance costs.

The present invention provides a method for painting steel pipe sheet piles to solve these problems, which involves moving the steel pipe sheet piles back and forth and spraying paint onto them, and which sets the circumferential position during initial and continuous operation and allows painting to be done without an operator having to enter the painting booth, without being affected by the painting environment, with little capital investment and maintenance-free equipment.

(Means for solving the problem) Figure 6 is an explanatory diagram of a longitudinal coating pattern of a steel pipe sheet pile,
The figure shows a front view of an example of an apparatus used in the method of the present invention.
The figure is a side view of the device, and Fig. 3 is an explanatory diagram of the control panel. That is, the method of coating the outer surface of a steel pipe sheet pile according to the gist of the present invention is, as shown in the embodiment examples of Figs. 1 to 3, the outer surface of the steel pipe at the end of the steel pipe sheet pile 1 is aligned in the circumferential direction by a rotary drive body 3, and then the steel pipe sheet pile 1 is moved back and forth on a rail by a carriage 2, and this spray coating is carried out continuously. At the center upper part of the steel pipe sheet pile 1, a left-right moving stand 13, an elevating moving stand 12 are installed with an ITV 14, a pulse generator 11, and a rotational movement amount setting digital switch 17, and the rotary drive body 3 which can be repeatedly operated and a cumulative set rotation amount difference calculation display 1 are installed.
This is a method for coating the outer surface of a steel pipe sheet pile, characterized by repeatedly coating using an apparatus consisting of:

The conditions of the present invention will be explained in detail below based on the embodiment examples shown in Figs. 1 to 3. Fig. 1 is a front view showing an example of an apparatus for carrying out the method of the present invention, and Fig. 2 is a side view of the same. As shown in the figure, the coating of the steel pipe sheet pile is carried out by a spray gun 6, which is a coating machine, and a gun stand 4, which are provided along the movement of a carriage 2 carrying the steel pipe sheet pile 1. Simultaneously with the spraying of the paint, the carriage moves, and the paint is sprayed onto a predetermined longitudinal position. The method of the present invention is a method for efficiently coating the entire outer periphery of the steel pipe sheet pile without omissions, and the apparatus for this purpose is the rotary drive body 3, pulse generator 11, and elevating and moving stand 1 shown in Figs. 1, 2, and 3.
2, a horizontally movable stand 13, an ITV 14, a rotational movement amount setting digital switch 17, and a cumulative set rotation amount difference calculation display 18. Next, the method of the present invention will be described. Fig. 5 shows a longitudinal coating pattern for a steel pipe sheet pile. The steel pipe sheet pile 1 shown in the embodiment of Figs. 1 to 3 is moved back and forth by a carriage 2 at n equally spaced circumferential positions according to the coating pattern shown in Fig. 5, and is efficiently coated without omissions using a spray nozzle 6 attached to a robot or fixed gun stand 4. The ITV 14, which is previously set at the upper center of the steel pipe sheet pile by the horizontally movable stand 13 and the liftable stand 12, captures an image of the initial coating position (Fig. 5A) and the steel pipe sheet pile T-shaped claw 15. The operator visually aligns the steel pipe sheet pile T-shaped claw 15 with the rotation driver 3 so that it is at the center of the image. The pulse generator 11 of the rotary drive body 3 then rotates the steel pipe sheet pile 1 at evenly spaced intervals according to the rotation amount set by the rotation movement amount setting digital switch 17, and the steel pipe sheet pile 1 is painted sequentially from direction B in Figure 5 to direction E, and then returns to the initial painting position in direction A in Figure 5.
At this time, if the cumulative set rotation amount difference calculation display 18, which is the cumulative difference between the set rotation amount from the A direction to the current coating direction and the actual rotation amount, is not within the positional deviation tolerance, the steel pipe sheet pile T claw 15 is re-aligned with the center of the image projected by the ITV 14 as described above, and coating is repeated the set number of times. This method reduces the film thickness variation between the steel pipe sheet pile 1 itself and other steel pipe sheet piles, and also improves the safety and health of the operator. The ITV 14 is adjusted to fit the size of the steel pipe sheet pile 1.
It can be set up using the left-right moving stand 13 and the up-down moving stand 12, and is not affected by the painting booth 9, which is the painting environment, so it can be implemented with a small capital investment.

(Example) When spray painting 2.5 mm of urethane elastomer around half of a steel pipe sheet pile, the ITV 14 is adjusted to align the image by using the left-right moving platform 13 and the lifting moving platform 12 at the center of the span width of the rotary drive body 3 in the embodiment example shown in Figures 1 to 3.
This position is the initial stop position. Next, the rotational movement amount of the rotary driver 3 is set using the rotational movement amount setting digital switch 17 according to the number of directions that can evenly divide the outer circumferential length of the steel pipe sheet pile by 1/2 or less of the spray pattern 7. The number of coats to be applied for each number of directions is determined from the speed of the carriage 2 calculated from the urethane elastomer sagging limit film thickness and the discharge amount. Each time the initial position and the cumulative set rotation amount difference calculation display 18 during the above-mentioned coating rotation continuous coating exceed the allowable value, correction is made by inching the rotary driver 3 at the center of the image of the steel pipe sheet pile T-jaw 15 and ITV 14.

For example, in the case of a 400φ steel pipe sheet pile, the ITV 14 is installed at the center of the 400 mm span width of the rotary driver 3 by the left-right moving stand 13, and the steel pipe sheet pile T-claw 15 is adjusted by the lifting and moving stand 12 so that it is at a good image projection distance of 1000 mm. When painting is done equally in four directions, the number of repaints is 7, the painting cart speed is 30 m/min, and the rotation section is divided equally in four directions, so the set rotation amount of the rotary driver 3 is (400 x π)
Set it to /(2 x 3) = 210 mm. The optimum nozzle angle for the steel pipe sheet pile T-jaw 15 is 27.1 to 33.4 degrees, so the allowable cumulative set rotation amount difference is ±3 mm. After initial stop positioning, by repeating position correction each time the cumulative set rotation amount difference calculation display 18 exceeds the allowable value, it is possible to reduce film thickness variations within the steel pipe sheet pile and between other steel pipe sheet piles.

(Effects of the Invention) The outer periphery coating method for steel pipe sheet piles of the present invention has the following excellent effects compared to conventional methods.

Compared to conventional positioning based on the operator's intuition, the coating position is fixed and reproducible, reducing film thickness variations within the steel pipe sheet pile itself and between other steel pipe sheet piles, leading to cost reductions.

This can be applied to the anticipated future measures to make the film thickness of the claws uniform (robot painting with fixed position settings).

The operator does not have to enter the painting booth, improving safety and hygiene.

It is not affected by the painting environment, is maintenance-free, and can be installed with a small capital investment.

[Brief explanation of the drawings]

Fig. 1 is a front view of the device in an embodiment of the present invention, Fig. 2 is a side view of the same, Fig. 3 is an explanatory diagram of the control panel, Fig. 4 is a front view showing a conventional coating method, Fig. 5 is an explanatory diagram of the coating pattern in the longitudinal direction of the steel pipe sheet pile, and Fig. 6 is an explanatory diagram of the appropriate lap allowance. 1...steel pipe sheet pile, 2...carriage 3...rotational drive body, 4...gun stand 5...swivel joint 6...spray gun, 7...spray pattern 8...control panel, 9...painting booth 10...lap allowance 11...pulse generator 12...lifting and moving stand 13...left and right moving stand 14...ITV, 15...steel pipe sheet pile T-jaw 16...image 17...rotational movement amount setting digital switch 18...accumulated set rotation amount difference calculation display

──────────────────────────────────────────────────── Continued from the front page (72) Inventor: Yoshiyuki Kawase 1 Kimitsu, Kimitsu City, Chiba Prefecture, Japan Nippon Steel Corporation, Kimitsu Works (72) Inventor: Fumihiko Chino 1 Kimitsu, Kimitsu City, Chiba Prefecture, Japan Nippon Steel Corporation, Kimitsu Works (72) Inventor: Fumihiko Chino 1 Kimitsu, Kimitsu City, Chiba Prefecture, Japan Nippon Steel Corporation, Kimitsu Works (56) References: JP 61-178057 (JP, A) JP 49-101478 (JP, A) JP 62-68565 (JP, A)

Claims (1)

[Claims] [Claim 1] A method for continuously spray-painting the steel pipe sheet pile by moving the steel pipe sheet pile back and forth in the longitudinal direction after circumferentially aligning the outer surface of the steel pipe at the end of the steel pipe sheet pile with a rotary drive body, the method comprising: an ITV having left and right movement and up and down movement functions for imaging the outer peripheral surface of the steel pipe sheet pile; a steel pipe sheet pile rotary drive body capable of repeatedly operating at a set rotation amount; and a function for calculating the cumulative set rotation amount difference during repeated rotation operation; the rotary drive body aligns the position based on the image captured by the ITV; and the steel pipe sheet pile is then rotated at intervals equally divided by the rotation amount set by the pulse generator of the rotary drive body;
A method for coating the outer surface of a steel pipe sheet pile, characterized in that if the cumulative set rotation amount difference calculation display is not within the allowable value, the coating is repeated after realignment.