JPS62160163A - Method for painting picture frame made of steel plate - Google Patents

Abstract

PURPOSE:To equalize the thickness of a paint film and to linearize the boundary line with a non-painting part, by controlling the horizontal movement of two sets of painting spray guns and the tilting thereof in a vertical plane on the basis of the entering time and width of a steel plate detected by an image sensor. CONSTITUTION:A spray gun 4 horizontally moves by a distance B1 from the position near to the side of a plate width center line by a predetermined distance A0 from the side edge of a steel plate 2 on the basis of the detection signal of an image sensor while spraying paint to the steel plate 2 and subsequently sprays the paint to the range of the distance B2 while tilting to the center line side at a predetermined angle theta1. A spray gun 6 horizontally moves over the distance from one side edge of a central area C to the other side edge thereof to perform spraying and subsequently sprays the paint to the range of the distance B2 while tilting to the side edge of the steel plate 2 at a predetermined angle theta2. Succeedingly, the next paint film 20 is formed but, at this time, a reciprocating stand having each gun arranged thereto and the steel plate 2 are relatively moved so as to be shifted by the width of the paint film and the guns 4, 6 are returned to the original positions during this time.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a picture frame coating method and apparatus for painting a moving steel plate to a predetermined thickness except for a predetermined width on the front and back peripheral edges. It is something.

(b) Conventional technology When steel plates are coated with paint, etc., there are problems such as the paint decomposing during welding, emitting toxic gases, and causing welding defects such as blow holes, which can cause welding lines. A so-called frame-painted steel plate is manufactured in which a non-painted portion is formed on the peripheral edge of the steel plate.

Frame-painted steel plates are painted on non-painted areas before painting using a coating device equipped with a conveyor platform that moves the steel plate and a coating nozzle that moves back and forth in the width direction of the steel plate and sprays paint onto the steel plate. It was manufactured by attaching tape to the peripheral edge of the steel plate in advance, applying paint on top of it, and peeling off the tape after painting.

However, this method requires a lot of time and effort to apply and peel off the tape, and is not efficient. Therefore, a coating device was developed that automatically forms non-painted areas on both side edges of the steel plate by placing shielding plates close to the top along both sides of the steel plate when the steel plate passes through the painting area. It was done. This device has significantly reduced the amount of work required. However, even in this device, the paint adhered thickly to the shielding plate, and it could not be put to practical use unless it was cleaned periodically or continuously.

Therefore, a method has been proposed in which picture frames are painted simply by controlling on/off of a paint spray gun without using a shielding plate. This method uses a single method in which only a single spray gun is reciprocated in the width direction of the steel plate to apply the coating, and a main spray gun that reciprocates in the center of the steel plate in the width direction and a secondary spray gun that reciprocates in the long side edges. There is a double method (Japanese Unexamined Patent Publication No. 101760/1983) in which the coating is applied using the same technique.

However, in the single method, as shown in Figure 7 (~), excessive coating occurs on the long side edges, and to prevent this, the head of the spray gun is shaken when the spray gun approaches the long side edges. (tilted), but for that reason the figure 7 (
As shown in B), an undercoated film is formed and the boundary line with the non-coated area is disturbed.

Furthermore, in the double method, as shown in FIGS. 7FC) and 7(D), variations in coating film thickness occur at the long side edges, which is unfavorable in terms of quality.

In order to solve the above-mentioned drawbacks of this double method, the present applicant disclosed ``Method and Apparatus for Painting Picture Frames of Steel Plate'' (Japanese Patent Application No. 59-236023) dated November 9, 1981.

This method involves installing an image sensor at the entrance of the coating line to determine when the steel plate is entering the coating line and painting the steel plate to a desired thickness while leaving a predetermined width on one or both long side edges of a moving steel plate. A pair of first painting spray guns capable of detecting the width of the steel plate and capable of horizontal movement and tilting in a vertical plane are installed on the output side of the image sensor and symmetrically with respect to the center line of the painting line on the long side side. The first paint spray gun is installed toward the edge of the steel plate based on the detection signal from the image sensor, and the first paint spray gun is directed toward the center line by a predetermined distance from the side line of the long side of the steel plate while spraying paint onto the steel plate. Use of the first painting spray gun, which is a second painting spray gun that can be moved horizontally and then tilted by a predetermined angle toward the center line, and can be moved horizontally and tilted in a vertical plane. (1111f-6) When applying the paint to the steel plate, the second painting spray gun is activated to spray the paint onto the steel plate based on the detection signal from the image sensor. while horizontally reciprocating by a predetermined distance toward the long side edge in the width direction of the steel plate, and tilting by a predetermined angle toward the long side edge when reaching the vicinity of the long side edge. It consists of

In this method, the steel plate is moved and the first and second painting spray guns are stopped, so that the short sides of the steel plate, that is, the side edges of the top and bottom parts of the steel plate are painted. If you try to leave the side edges of the top and bottom parts unpainted using this method, as shown in Figure 8,
The triple-hatched area S3 is thicker than the others, and the single-hatched area S1
will be painted thinner than the others. This occurs because the painting of the steel plate while it is running overlaps with the painting of the steel plate while it is stopped.

(c) Problems to be Solved by the Invention The problems to be solved by the present invention are that when painting using a paint spray gun, it is necessary to equalize the coating film thickness on the concave side edge of the steel plate, and to unpaint it. The object of the present invention is to obtain a coating method that improves the linearity of the boundary line between the parts.

B.) Means for Solving the Problems The method for painting frames on steel plates of the present invention is characterized in that the painting process is carried out in a painting line that paints a running steel plate to a desired thickness while leaving a predetermined width at the peripheral edge of one or both sides of the steel plate. An image sensor is installed at the line entrance to detect the timing of the steel plate entry and the width of the steel plate, and it can be moved horizontally and tilted in the vertical plane.
A first painting spray gun of the pair is mounted on the long side on the output side of the image sensor and symmetrically with respect to the center line of the painting line.

A second painting spray gun, which is installed on a carriage facing the side edge and can be moved horizontally and tilted in a vertical plane, is installed on the entrance or exit side of the first painting spray gun and near the center of the steel plate. , the carriage is synchronized with the running speed of the steel plate at a predetermined period and for a predetermined time, and is deviated relative to the running speed of the steel plate for another predetermined time in the period. moving in the direction of the painting line at a speed determined by the image sensor, and alternately setting the traveling speed synchronization and asynchronous periods; moving the spray gun horizontally toward the center line by a predetermined distance from the long edge of the steel plate while spraying paint onto the steel plate, and then tilting the spray gun by a predetermined angle toward the center line, during the traveling speed synchronization period; , based on the detection signal from the image sensor, the second painting spray gun is horizontally moved back and forth a predetermined distance toward the long side edge in the width direction of the steel plate while spraying paint onto the steel plate; tilting by a predetermined angle toward the long side edge when reaching the vicinity of the long side edge, and returning the first and second painting spray guns to their original positions during the traveling speed non-synchronization period. By doing so, the above problem is solved.

(Feather Example) The method for painting a frame of a steel plate according to the present invention will be specifically explained with reference to FIGS. 1 to 5.

First, before we get into the specific explanation, we would like to clarify the following assumptions (
. The picture frame steel plate to which the present invention is directed is one that is coated to a desired thickness with a predetermined width left on the peripheral edges on both the front and back surfaces or on one side. The short edges of the steel plate are also not coated. For convenience of explanation, the case where the surface of a steel plate is painted will be described below.

Furthermore, in principle, the method of the present invention provides the same result even if the long side edges of the steel plate are painted first and then the central part is painted, or vice versa. Therefore, for convenience of explanation, the former painting process will be explained below.

First, as shown in FIG. 1, in the coating line 1, a steel plate 2 is placed on a table roller 11 (FIG. 2) and sent to a coating apparatus, and then the steel plate being coated is conveyed. A conventional sight guide 12 is provided at the entrance to the coating line 10 to align the steel plate 2 with the centerline 13 of the coating line 1.

Since the center line 13 is a virtual position, this center line 13
The auxiliary reference line I4 that determines the painting line is the painting line.Paint spray guns 4 and 6, which will be described later, are positioned with reference to this auxiliary reference line 14.

As shown in FIG. 3, a non-painting area A, a side edge area B, and a center area C are provided with the auxiliary reference line 14 as a reference. The non-painted area A includes the actual non-painted portion A on the steel plate 2. will be established. The side edge area B has a single layer portion B1 and a multilayer portion B.
It is made up of 2.

The above explanation has been made regarding the long side edges of the steel plate, but regarding the short side edges of the steel plate, the unpainted area is based on the top edge or bottom edge of the steel plate.

(Figure 2) is determined.

An apparatus for carrying out the method of the present invention will be briefly described with reference to FIGS. 1 to 3.

The picture frame painting device of the present invention includes an image sensor 3, a pair of first painting spray guns 4, a first painting/gas spray gun drive mechanism 5, a second painting spray gun 6, and a second painting spray gun drive mechanism. 7. The carriage 8 and carriage drive mechanism 9 are also completed.

The image sensor 3 detects the width of the steel plate of the side guide 12. The detection signal is sent to the central control device (not shown)
sent to.

A first painting spray gun drive mechanism (hereinafter referred to as the first mechanism) 5 is arranged on the exit side of the image sensor 3 and symmetrically with respect to the center line 13 of the painting line 1 . The first mechanism 5 moves the first painting spray gun 4 horizontally in the width direction of the steel plate 20 and tilts it in a vertical plane (in a plane perpendicular to the plane of the paper in FIG. 1). support.

A control signal from a control device (not shown) is sent to the first mechanism 5 to control the operation of the spray gun 4. That is,
The first painting spray gun 4 faces the long side edges of the steel plate 2 in a symmetrical manner with respect to the center line 13, and moves horizontally in the width direction of the steel plate 2, and also in the horizontal movement direction within the vertical plane of the steel plate 2. tilt.

The spray guns 4 and the first mechanisms 5 are provided symmetrically in pairs on the left and right sides of the center line 13, one on top and one on top of the other.

A second painting spray gun drive mechanism (hereinafter referred to as the second mechanism) 7 is located on the output side of the image sensor 3 and is connected to the first mechanism 5.
placed adjacent to. The second mechanism 7 is configured to move the second painting spray gun 6 horizontally in the width direction of the steel plate 2 and to tilt the spray gun in a vertical plane (in a plane perpendicular to the plane of the paper in FIG. 1). I support 6.

A control signal from a control device (not shown) is sent to the second mechanism 7 to control the operation of the spray gun 6.

The first and second mechanisms 7 are fixedly supported on a carriage 8, as shown in FIG. The carriage 8 has a carriage drive mechanism 9
is moved in the direction of painting line 1 by .

(F) Function The function of the method of the present invention will be explained with reference to FIGS. 1 to 4.

The center of the steel plate 2 before painting is aligned with the center line 13 of the painting line 1 using the sight 9 and the guide 12. The image sensor 3 detects the approach of the steel plate 2 and the width of the plate. The detection signal is sent to the central control device, and based on the manufacturing specifications, the coating area A1, the side edge area B, the central area C1, and the non-coating area A are selected.

, single layer portion B1, and multilayer portion B2 are determined.

The conveyance speed of the steel plate 2 is detected from the rotation speed of the table roller 11 and sent to the control device. The controller sends control signals to each drive mechanism 5.7.9 to control the operation of each spray gun 4.6.

As shown in FIG. 3, the spray gun 4 is placed at a predetermined distance A from the side edge of the steel plate. Spray paint onto the steel plate from a position closer to the center line of the bamboo steel plate width while moving horizontally a distance B0, then tilting the spray gun 4 by a predetermined angle θ towards the center line and spraying paint over a distance B2. Spread. The spray gun 6 horizontally moves the distance from one side edge of the central area C to the other side edge of the central area C while spraying paint onto the steel plate, and then moves the spray gun at a predetermined angle θ2 toward the side edge of the steel plate. Spray paint over a distance B2 while tilting.

After all, in the range of distance B2, the paint from both spray guns 4 and 6 overlaps, forming a multi-layer, and the other coating film is A case was made in which a single strip of coating film 20 (FIG. 4) having a predetermined width was formed in the width direction of the steel plate 2 while the steel plate 2 was traveling in synchronization with the traveling speed of No. 2. Subsequently, in order to form the next coating film 20, the carriage 8 and the steel plate 2 must be relatively displaced.

For this purpose, for example, as shown in FIG. 4, when painting is started from the bottom side of the steel plate 2, the traveling speed of the carriage 8 is set at a speed . 2, it is sufficient to run the vehicle for a time t2.

Here, the time T-t2 is the time during which one strip of the coating film 20 is formed, and the time t2 is the time when the carriage 8 forms the coating film 20.
This is the time leading by the width W of .

When coating is started from the top side of the steel plate 2, the speed ■2 of the carriage 8 may be made smaller than ■□, or the carriage 8 may be stopped altogether.

During the period when the carriage 8 is deviated relative to the steel plate 2 by the width W of the coating film 20, the first and second mechanisms 5 and 7 return each spray gun 4 and 6 to their original positions.

The above operations are repeated one after another, and the picture frame painted steel plate 2α (first
Figure) is obtained. In the coating film of the steel plate 2a, parts B and C are single layers, and part B2 is a multilayer (sixth layer).
figure). Further, the coating unevenness S3 (FIG. 8) as described above does not occur on the top and bottom of the steel plate 2, and the coating film 20 is evenly formed.

FIG. 5 is a schematic explanatory diagram when painting the front and back surfaces of the steel plate 2. In this embodiment, reversing machines 10 are provided along the coating line 1 at a predetermined distance (a distance sufficient to complete coating one side of the steel plate 2).

While the preceding steel plate 2 is being painted, the trailing steel plate 2 is kept on standby (A). When the painting of the preceding steel plate 2 is completed,
The steel plate 2 is sent to a reversing machine 10 and reversed (A).

CB) which paints the trailing steel plate 2 following the carriage 8 on its return trip. The reversal leading steel plate 2, which has been painted on one side, follows at the same time ((B)).

After completing the painting on one side of the trailing steel plate 2, the reversing machine 1 on the upstream side
CB to be sent to 0 and inverted).

The back side (unpainted side) of the following single-sided painted steel plate 2 is painted on the outbound trip (C). In this way, painting of the front and back surfaces of the preceding steel plate 2α is completed (C).

In step 5, the front and back surfaces of the steel plate 2 are sequentially painted (CD).

(G) Specific Example: A thick steel plate with a thickness of 20mm x width of 3200mm x length of 12192mm is transported at a rate of 2.5m/min, and the width of the non-coated part is A.

was set to 50 mm. The overall coating condition was a film thickness of 3゜μm.
±5 μm The width B of the first pre-coating band is 150 rtrm, and the second
The moving layer C of the painting spray gun 6 is set to 2800 rrrm.

The traverse speed of the second painting spray gun 6 was set to 18 m/min, the pattern length was set to 0.8 m, and spraying was carried out continuously. Set the swing angle (tilting angle) θ2 of the spray gun 6 to (45°). The traverse width B1 of the first painting spray gun 4 is 50 m.
The traverse speed is 45 m/min, the time required for reciprocating is every 3 seconds, and for 1.5 seconds, spraying is performed while moving toward the center line of the board width, and for the remaining 1.5 seconds, there is no spraying. I decided to retreat to the initial position. Set the swing angle θ□ of the spray gun 4 to (45°).

The width W of one strip of the coating film 20 was set to 420 mm, and the coating was started from the top side of the steel plate, and after the coating of one strip of the coating film 2o was completed,
Traveling of the carriage 80 is stopped for 6 seconds. As a result, 3
The relative position of the spray gun 6 and the steel plate 2 in the longitudinal direction shifts by a width W=420wn every second.

When painting was carried out under the above conditions, it was possible to paint a picture frame with smoothness and good linearity as shown in FIG.

(Strength effect) According to the method of the present invention, the boundaries between the painted and non-painted parts at the long and short side edges of the steel plate are clear, and the coating film thickness is almost uniform.As a result, variations in color tone There is no cracking of the paint film during bending.

Figure 1 is a plan view of a picture frame painting apparatus for carrying out the method of the present invention. Figure 2 is a front view taken from the line ■-■ in Figure 1. FIG. 3 is a schematic explanatory diagram showing the picture frame painting method of the present invention. FIG. 4 is a graph showing the relative speed relationship between the carriage and the steel plate. FIG. 5 is an explanatory diagram showing a method of painting the front and back surfaces of a steel plate. FIG. 6 is an explanatory diagram showing the state of coating film thickness according to the method of the present invention. FIG. 7 is an explanatory diagram showing the state of coating film thickness according to the conventional method. FIG. 8 is an explanatory diagram showing the state of a coating film on the surface of a steel plate coated by the method of the present invention.

1: Painting line 11: Table roller 12: Side guide 13:
Center line 14: Auxiliary reference line 2: Steel plate
3: Image sensor 4: First painting spray gun 5: First painting spray gun drive mechanism 6: Second painting spray gun 7: Second painting spray gun driving mechanism 8: Carriage carriage 9: Carriage carriage drive mechanism 10 : Reversing machine Fig. 7 Fig. 8

Claims (1)

[Claims] In a painting line that paints a moving steel plate to a desired thickness while leaving a predetermined width around the peripheral line on one or both sides, an image sensor is installed at the entrance of the painting line to detect when the steel plate enters and the width of the steel plate. In particular, a pair of first painting spray guns capable of horizontal movement and tilting in a vertical plane are reciprocated toward the long side edges on the exit side of the image sensor and symmetrically with respect to the center line of the painting line. A second paint spray gun, which can be installed on a stand and can be moved horizontally and tilted in a vertical plane, is attached to the carriage at the entrance or exit side of the first paint spray gun and toward the vicinity of the center of the steel plate. installing the carriage in a predetermined period and for a predetermined time in synchronization with the traveling speed of the steel plate, and in the period, for another predetermined time in the direction of the painting line at a speed relative to the traveling speed of the steel plate; and alternately setting the traveling speed synchronization and asynchronous periods, and during the traveling speed synchronization period, the first painting spray gun is applied to the steel plate based on the detection signal from the image sensor. horizontally moving toward the center line by a predetermined distance from the long side edge of the steel plate while spraying the steel plate, and then tilting the steel plate by a predetermined angle toward the center line; Based on the detection signal, the second painting spray gun is horizontally moved back and forth a predetermined distance toward the long side edge in the width direction of the steel plate while spraying paint onto the steel plate, and near the long side edge. a steel plate picture frame, the frame comprising: tilting a predetermined angle toward the long side edge when reaching the frame; and returning the first and second painting spray guns to their original positions during the traveling speed non-synchronization period; Painting method.