JPH0248075A - Painting method - Google Patents

Abstract

PURPOSE:To prevent build up of a paint in the boundary part near vertical surfaces by spraying the paint to the horizontal surfaces of a material to be coated thinly in the boundary part near the vertical surfaces and to the thickness above the threshold in the other parts and the thickness above the sag threshold of the vertical surfaces and drying while rotating around horizontal axial line. CONSTITUTION:The material W to be coated such as automobile body is mounted on the horizontal axial line of a truck D, is subjected to a prepn. stage P1 such dust removal and is sent to a painting stage P2 where the spraying of the paint to the material W to be coated is executed in such a manner that the paint is thin in the to be coated part of the horizontal surfaces near the vertical surfaces and has the thickness above the sag threshold in the other parts and the vertical surfaces are coated to the thickness above the sag threshold while the overspraying to the boundary part with the horizontal surface is permitted. While the material W is rotated around the horizontal axial line in a setting stage P3, the paint is baked in a manner as not to generate the sag in a baking stage P4. The smoothness of the coated surface is improved in this way and the build up of the paint in the boundary part is prevented.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a coating method.

(Prior art) When painting the outer surface of an object to be coated, for example, an automobile body, by spraying, there are a preparation step for removing dust adhering to the object to be coated, a step of spraying and applying paint to the object to be coated, and a drying step of drying the applied paint. This drying process is generally carried out in two stages: a setting process and a baking process. It is carried out in an atmosphere with a temperature of 140°C to 60°C (the baking temperature in the baking process is usually around 140°C).

The object to be coated is usually conveyed by means of transportation such as a trolley while going through the above preparation process, painting process, and drying process. It is still being done.

By the way, one of the criteria for evaluating the quality of painted surfaces is:
It has smoothness (flatness), and the higher the smoothness, the smaller the degree of unevenness on the painted surface, resulting in a better painted surface. It is already known that in order to improve the smoothness of the painted surface, the thickness of the paint film, that is, the film thickness of the applied paint can be increased.

On the other hand, paint sag is a factor that impedes the quality of the painted surface. This sagging is caused by the applied paint flowing downward due to the force of gravity.
The cause of this "sag" is the effect of small force, so the surface of the object to be coated that extends in the vertical direction, that is, the so-called vertical surface. It is more likely to occur in For example, when considering the body of a car as the object to be coated, sagging is less likely to occur on the side surfaces of the bonnet and trunk lid, but sagging is more likely to occur on the fender, which is the q surface.

Therefore, on surfaces extending in the horizontal direction of the object to be coated, that is, so-called lateral surfaces, where "sagging" of the paint is less of a problem, the thickness of the paint applied can be made larger than on the vertical surfaces. In addition, even if the thickness of the paint film on the horizontal surface and the thickness of the paint film on the vertical surface are the same, the unevenness on the horizontal surface will be reduced due to slight flow of the paint that does not cause sagging.
This results in better smoothness than in the vertical plane.

From the above-mentioned viewpoint, conventionally, in order to obtain a painted surface as smooth as possible while preventing "sagging" of the paint, painting was done using a paint with as little fluidity (low viscosity) as possible. was. The so-called "sag limit" at which paint sag occurs on the vertical surface is a maximum coating thickness of about 40 μm for conventional thermosetting paints. More specifically, "sagging" of thermosetting paints tends to occur at the beginning of the setting process and at the beginning of the baking process, especially at the beginning of the baking process. The thickness of the paint is determined, and the legal maximum thickness, ie, the sagging limit value, is about 40 μm. Therefore, in order to obtain a painted surface with even greater absolute smoothness, with conventional painting methods, it is necessary to repeat the series of steps from the painting process to the baking process multiple times, for example by applying two coats. was there.

(Problems to be Solved by the Invention) It is possible to overcome the sagging limit that is a problem when painting by spraying as described above, and to obtain a painted surface with better smoothness for the same thickness of paint film. The applicant has developed a coating method that allows the above-mentioned results.

In other words, while applying the paint by spraying, the thickness of the paint film should be greater than the sag limit, and the object to be coated should be rotated around the approximately horizontal axis until the applied paint has cured to the point where no sag occurs. We have developed a painting method that rotates the paint. According to this coating method, the rotation of the object to be coated changes the direction of gravity acting on the paint, preventing sagging, and
By actively utilizing the large fluidity of paint, it is possible to obtain a painted surface with superior smoothness if the thickness of the paint film is the same.

However, when applying the painting method described in "-", the paint tends to concentrate at the corner where the side surface and the vertical surface are connected, and after the paint dries, the painted surface at this corner becomes partially large and thick. It turns out that this causes a problem. In particular, when spraying paint on side surfaces and vertical surfaces, conventionally the corners would be sprayed with paint from both directions (overspray).
, there is a tendency for the coating film to become thick.

In particular, the boundary portion of the lateral surface near the vertical surface is important in terms of appearance, so the problem is how to prevent the paint film from partially building up at this boundary portion.

Therefore, it is an object of the present invention to provide a coating method that utilizes paint spraying above the sag limit and rotation of the object to be coated about a substantially horizontal axis, in which a coating film is formed on the boundary portion of the horizontal surface near the vertical surface. To provide a coating method capable of preventing swelling of the paint.

(Means and operations for solving the problems) In order to achieve the above-mentioned object, the present invention has the following configuration. That is, a coating method that includes a coating process in which paint is applied by spraying to horizontal surfaces extending in the horizontal direction and vertical surfaces extending in the vertical direction of the object to be coated, and a drying process in which the applied paint is dried. The paint is sprayed onto the lateral surface so that the boundary portion of the lateral surface near the vertical surface is thin, and the thickness of the other portions other than the boundary portion is greater than the sag limit; The paint is sprayed onto the vertical surface so that the thickness is greater than the sag limit while allowing overspray to the boundary, and in the drying step, the paint applied to the object does not sag. The object to be coated is rotated around a substantially horizontal axis until it is cured.

In this way, in the present invention, the direction of gravity acting on the paint applied to the object to be coated is changed by rotating the object around the approximately horizontal axis, so that the paint does not sag. It will be dried without any drying.

According to the present invention, the film thickness of the paint applied per coat can be made much thicker than before, and an extremely good painted surface with smoothness that far exceeds the level conventionally considered to be the limit can be obtained. can.

Further, even when the thickness of the coating film is the same as that of the conventional coating, the fluidity of the coating material can be utilized to obtain an excellent coated surface with smaller irregularities, that is, greater smoothness.

Furthermore, if you try to obtain a painted surface with the same smoothness, for example, the same level of smoothness as that obtained with conventional painting methods,
The film thickness of the paint to be applied can be made thinner than in the conventional method, and the amount of paint used can be reduced by the amount that can be made thinner.

In the present invention, when spraying paint on a side surface, the boundary portion near the vertical surface of the side surface where the problem of partial swelling of the paint is a problem. Since it is made to be thinner than the other parts, even if it receives opus braking from spraying paint on the vertical surface, this boundary part will not become extremely thick compared to other horizontal parts. . As a result, the thickness of the coating film obtained at the boundary after the paint dries is the same or slightly thicker than that of other parts of the lateral surface, which is preferable in terms of appearance. Of course, it is preferable that the boundary portion is not too thick, not only because the amount of paint used can be reduced, but also because the time for rotating the object to be coated can be minimized.

It should be noted that spraying the paint in the horizontal direction and spraying the paint in the vertical direction may be performed either first, or they may be performed simultaneously. However, it is preferable to spray the side surfaces first, since there is a longer margin of time for sag to occur on the side surfaces than on the vertical surfaces.

Here, the paint may be sprayed by electrostatic coating. In addition, paint sag refers to the movement of paint that can be visually confirmed when the paint is left in the sprayed state (it appears as streaks when the paint hardens), and is generally about 2 mm. Sagging is considered to have occurred when movement of the paint is confirmed. Therefore, spraying paint to a thickness that exceeds the sag limit means spraying the paint to a thickness that will cause at least 2 mm of paint movement if left as is, and the more fluid the paint used, the more likely it will sag. The critical thickness becomes smaller. To achieve a thickness that exceeds this sag limit, it may be sprayed once (1
(stage blowing), the final thickness may exceed the sag limit by spraying two or three times or more (multi-stage blowing). Furthermore, the rotation of the object to be coated around the approximately horizontal axis should be done in such a way that the paint does not move significantly due to the action of gravity. The rotation may be performed continuously or intermittently in one predetermined direction until the material is cured, or the forward and reverse rotations may be performed continuously or intermittently. The rotation angle range of the object to be coated should be such that the direction in which gravity acts is reversed for any part where the paint is sprayed to a thickness above the sag limit, and 270° is sufficient. . and,
The axis of rotation of the object to be coated may be inclined within a range of about 30 degrees with respect to the true horizontal axis, and this axis of rotation may also be swung.

(Example) Hereinafter, an example of the present invention will be described based on the attached drawings.

Figure 1 shows the entire process for painting an automatic Ichikawa body W as an object to be painted, and each process is designated by P1 to P4.

First, the body W, which has been undercoated by electrodeposition coating in a known manner, is sent to a preparatory step P1 while being held on a trolley. In this preparatory step PI, dust inside and outside the body W is removed by, for example, air blowing or vacuum suction. Thereafter, paint is sprayed onto the body W at about 1° P2. Then, the paint is dried in a setting step P3 and a baking step P4.

If the steps P1 to P4 are for intermediate coating, the body W is sent to the top coating step after step P4. Also, process P
If I to P4 are for painting, the body W is conveyed to the assembly line in a known manner.

Dust removal in the dust removal step P1 is preferably performed while rotating the body W around the horizontal axis C, as shown in FIG. That is, for example, first, the rotation of the body W is stopped in the state shown in FIG. 2(a) to remove dust, and then the attitude of the body W is changed to the state shown in FIG. 2(b). It is stopped at the lever position and the dust is removed again. In this way, dust is removed while the body W is intermittently rotated as shown in (c), (d), . . . (1) in FIG.

In this way, by removing dust while rotating the body W, it is possible to remove dust adhering to closed sections such as the inside corners of the roof panel and side sills of the body W, i.e., if the body W is not rotated. It becomes possible to completely remove debris that does not fall (1).

First, the spraying of the paint in P2 is carried out so that the thickness of the paint film is below the sag limit. In other words, with conventionally commonly used paints, the maximum thickness of the paint that does not cause "sag", that is, the sag limit value, is about 40 μm, but in process P2, the paint film is much thicker than this sag limit of 40 μm. The paint is sprayed so that the thickness becomes (for example, 65 μm). Of course, the sag limit film thickness can be set to a sufficiently small value, for example, 30 μm (adjusting the content of the solvent and anti-sag agent), so the absolute thickness of the paint to be applied is a particular problem in the present invention. This is not true.

The details of spraying the paint in this painting process P2 will be described later.

In the setting step P3, the body W is rotated horizontally as shown in FIGS. 2(a) to 2(a). That is,
The body W is rotated about a rotation axis 6 extending in the horizontal direction, and in the embodiment, this rotation axis β extends in the front-rear direction of the body W. Note that the temperature atmosphere in this setting step P3 is set to room temperature in the example, but it may be set to an appropriate temperature in a lower temperature range than the temperature atmosphere in the next baking step P5, such as 40° to 60°C. It is possible. Of course, this setting process P3 is to volatilize the low boiling point content in the paint in advance, and this will prevent pinholes from forming on the painted surface due to the rapid volatilization of the low boiling point content in the next baking process P5. Occurrence is prevented.

In the baking step P4, the paint is baked in an atmosphere at a temperature of 140° C., for example. Even in this P4, P
In the same way as the setting process in step 3, Figure 2 (a) to (i)
The body W is rotated in the horizontal direction as shown in FIG.

Due to the horizontal rotation of the body W at P3 and P4 described above, even if the paint is sprayed to a thickness exceeding the sag limit at P2, the paint dries without sagging. As a result, a high-quality coated surface with extremely high smoothness that could not be obtained with conventional coating methods can be obtained.

The third diagram of lacquer, sauce, and water is
This shows the influence of coating film thickness on the sag limit. In this Figure 3, the coating film thickness is 40 μm, 53 μm.
Three cases are shown: μm and 65 μm. It is understood that for any of these thicknesses, peaks of "sagging" occur both at the beginning of setting L and at the beginning of the baking process. In addition, the sagging limit is usually 1 to 2 m per minute.
This is the value when sagging of m occurs (visually 2 mm/
The coated surface is considered to be defective if the amount of sag is greater than 1 minute), and the maximum coating thickness that can be obtained within this range of sag limit F is about 40 μm with conventional paints.

On the other hand, FIG. 4 shows the influence on the smoothness when the body W is rotated in the horizontal direction and when it is not rotated. In FIG. 4, Δ indicates a state in which the body W is not rotated (conventional painting method). FIG. 4B shows the case where the body W is rotated 90 degrees and then reversed (second
Forward/reverse rotation between figures fa) and fc)). Figure 4C is
This figure shows a case where the body W is rotated by 135 degrees and then reversed (forward and reverse rotation between FIG. 2(a) and FIG. 2(d)). The fourth diagram shows the case where the body W is rotated 180 degrees and then reversed (forward and reverse rotation between FIGS. 2(a) and (e)). FIG. 4E shows the case where the body W is continuously rotated in the same direction (FIGS. 2(a), (b), (
c)... Take the posture in the order of (1) and return to (a) again).

As is clear from Fig. 4, if the thickness of the coating is the same, it is better to rotate the body W (Fig. 4 B, C, D, E).
), thicker smoothness can be obtained than in the case of no rotation (FIG. 4A). Furthermore, it is understood that even if the rotation is the same, it is preferable to rotate 360 degrees in the same direction in order to improve the smoothness. Of course, if the body W does not rotate,
Since there is a limit to the thickness of the coating film, there is a limit to how much smoothness can be increased.

By the way, assuming the thickness of the coating film is 65μm, the body W is 36mm.
When rotated by 0°, the obtained smoothness is r87J with a mapping sharpness of 1.0 (lower limit of 1.0 in PGD value).
It is. Moreover, when the thickness of the coating film is 40 μm,
If the body W does not rotate, 1. r58J in G (P
The lower limit of GD value is 0.7), but when the body W is rotated 360 degrees! , r68J in G (PG
The lower limit of the D value T0.8).

As is known, IG (image cross) in mapping sharpness indicates the ratio of sharpness to a mirror surface (black glass) of 1°O, and PGD indicates the degree of discrimination of reflected images. This is a value at which the smoothness of the painted surface decreases as the value decreases from 1.0.

The test conditions for the data shown in FIGS. 3 and 4 are as follows, and these test conditions indicate the conditions when overcoating is performed at P2.

a, Paint: Melamine Alkit (black) Viscosity: 22 seconds/206C with Ford Cup #4 b, Coating machine: Minibell (16, OOOrpm) Shaping air 1.2, Ok g/cm2 C1 discharge rate: 2 Spraying is divided into several times, the first time, ,
, 100cc/min 2nd time, 150~200cc/min, Setting time = 10 minutes x normal temperature e, Baking conditions: 140°C x 25 minutes F, Base smoothness: 0.6 (PGD value) (Intermediate coating, PE tape 2) g0 rotation or reversal operating range: Setting (10 minutes) to baking (10 minutes) h, Painted on the side of a rectangular cylinder with a knee side of 30 cm, supported rotatably at the center. i. Rotation speed of the object to be coated: 6 rpm, 30 rpm, 6
Although the rotation was carried out at three different rotational speeds, there was virtually no difference due to the difference in rotational speed. Note that the horizontal axis described here includes a range tilted by about 10' with respect to the true horizontal axis.

＋ 8 Construction The body W as the object to be painted in P2 is first sprayed with paint horizontally on the bonnet, trunk lid, roof panel, etc., and then on the vertical surfaces such as the fenders. Paint is sprayed against it.

In FIGS. 16 and 17, the side surface of the body W is denoted by 6.
1, and the elevation is designated by 62. Also, the side surface 6
The paint sprayed on No. 1 is designated by reference numeral 6 and is designated by reference numeral 63 as a base coat. FIG. 16 shows how paint is being sprayed onto the side surface 61.
FIG. 7 shows how paint is being sprayed onto an elevation 62. In addition, as a paint gun for spraying,
Known electrostatic coating machines (minibell) 64 (for side surfaces) and 6
5 (for elevation) is used.

In FIG. 16, the paint is sprayed in the horizontal direction 61 by reciprocating the paint gun 64 along the horizontal surface 6I at a constant speed. At this time, the side surface 61
A masking plate 66 is provided at the boundary between the vertical surface 62 and the vertical surface 62 so as to protrude from the horizontal surface 61 along the vertical surface 62. As a result, a boundary portion 61a near the vertical surface 62 in the horizontal direction 61
Most of the paint that should be applied to the area (the distance 4 from the surface of the base coating film 63 to the vertical surface 62) adheres to the masking plate 66. Therefore, the thickness of the paint sprayed onto the boundary portion 61a is the boundary portion 6 of the horizontal surface 61].
It is thinner by a predetermined amount than the other portion 61b other than a. The coating thickness of this other portion 61b is set to be less than the sag limit.

After spraying the paint onto the side surface 61, the paint is sprayed onto the vertical surface 62 by reciprocating the paint gun 65 along the vertical surface 62 at a constant speed, as shown in FIG. When spraying paint onto this vertical surface 62, the masking plate 66 mentioned above is removed. A portion of the paint discharged from the paint gun 65 is attached to the boundary portion 61a (overspray).

As a result, the thickness of the coating film on the boundary portion 6]a is approximately the same as that on the other portion 61b of the lateral surface 61. Of course, the coating thickness on the vertical surface 62 is set to be greater than the sag limit.

In this way, the thickness of the paint sprayed onto the boundary portion 61a is prevented from becoming extremely large, and as a result, the drying process])4
The coating film thickness of the boundary portion 61a finally obtained after passing through is prevented from being extremely thicker than the other portions 61b.

Note that the thickness of the paint sprayed onto the boundary portion 61a shown in FIG. 16 is made to be thinner by a predetermined amount than the other portion 61b, taking into account the degree of concentration of paint that occurs when the body W is rotated. It is also possible to leave it there.

Here, the paint may be sprayed first onto the vertical surface 62 shown in FIG. 17, and then the paint may be sprayed onto the side surface 61 shown in FIG. The paint may be sprayed onto the upper surface 62 and the vertical surface 62 at the same time. Furthermore, in order to make the thickness of the boundary portion 61a thinner than that of the other portion 61b, the painting gun 64 should be positioned at the right stroke end position in FIG. Also, in this case, the masking plate 66 may be omitted.

Box tJu1 Next, a specific example of a jig used for horizontally rotatably supporting the body W with respect to the trolley will be described.

Figure 5 shows the front jig I attached to the front of the body W.
Indicates F. This jig IF includes a pair of left and right mounting brackets 2, a pair of left and right stays 3 welded to each of the left and right brackets 2, a connecting bar 4 that connects the left and right pair of stays 3, and a connecting bar 4. It has a rotating shaft 5 integrated with. The bracket 2 portion of such a jig IF is fixed to the front strength member of the body W, for example, to the front end of the front side frame 11. That is, since a bracket 12 for normally mounting a panbar (not shown) is welded to the front side frame 11, the bracket 2 is attached to the bracket 12 on the front side of the body using bolts (not shown). Fix it.

On the other hand, the rear jig IR attached to the rear of the body W,
This is shown in FIG. The rear jig IR has the same configuration as the front jig IF, and components corresponding to the front jig 1F are given the same reference numerals. The rear jig IR is attached to the body W by fixing the bracket 2 to the floor frame 13 as a strength member at the rear end of the body W with bolts. Of course, at the rear end of the floor frame 13,
Since the bumper mounting bracket is generally welded by bolts because the bumper is mounted, the rear jig IR can also be mounted using this bumper mounting bracket.

4. When the front and rear jigs 1F and IR are attached to the body W, their rotating shafts 5 are positioned on the same straight line extending in the front-rear direction of the body W. This same straight line becomes the rotational axis ρ of the body W, and preferably this rotational axis β passes through the center of gravity G of the body W (see FIG. 7). Note that the axis of rotation β is the center of gravity G
This prevents the rotational speed from fluctuating too much when the body W rotates. As a result, body W has 1
The occurrence of shock due to rotational fluctuations is prevented, which is more preferable in terms of sag prevention.

Note that the front and rear jigs IF and IR are specially prepared in advance according to the vehicle type (type of body W).

Used in at least Pl, P4, P5, body W
It is a trolley with the function of rotating.

In FIG. 7, the platform weight has a base 21, and this base 2
Wheels 22 attached to 1 are run on a road surface 23-1. This base 21 is arranged from the 0;1 side in the running direction to the rear side (7th
It has one front column 24, two intermediate branches 25, 26, and one rear column 27, each extending in the L direction from the right side to the left side in the figure. 27 is a support space 28 with a large gap in the front-rear direction.

The body W is disposed in the support space 28, and its front part is rotatably supported with respect to the intermediate support 26 using the front jig IF, while its rear part is supported using the rear jig IR. It is rotatably supported by the rear support 27.

The front and rear jigs IF, IR (rotary shafts 5) are capable of engaging and disengaging from the columns 26 and 27 from above and below, and
The rear jig IR is immovably engaged in the direction of the rotation axis β. For this reason, the intermediate support 26 has a notch 26a that opens on its upper end surface (see FIGS. 10 to 12), while the rear support 27 has a notch 27 that opens on its upper end surface.
a is formed (see FIGS. 10, 14, and 15). These notches 26a, 27a are
The size is such that the rotary shaft 5 of R can fit therein. A flange portion 5a is formed on the rotating shaft 5 of the rear jig IR, and a notch 27b having a shape corresponding to the flange portion 5a communicating with the notch 27a is formed in the rear support 27. . As a result, the rear jig IR is engaged with and disengaged from the notches 27a and 27b of the rear column 27 from above and below, and is made immovable in the front and rear direction with respect to the rear column 27 by the stopper action of the flange portion 5a. Ru. In addition, body W
The rotational force is applied via the rotating shaft 5 of the front jig IF, and therefore a connecting portion 5b (see also FIG. 5), which will be described later, is provided at the tip of the rotating shaft 5 of the front jig IF. It is formed.

A stay 29 is provided to protrude downward from the base 21,
A traction wire 30 is connected to the lower end of this stay 29. This wire 30 is of an endless type,
It is driven in one direction by a motor (not shown), thereby driving the table (itl) in a predetermined transport direction. Of course, the above-mentioned Chiyo is installed in a safe location from an explosion-proof point of view.

The rotation of the body W is performed by using the movement of the truck, that is, by using the displacement of the truck with respect to the running road surface 23. The rotation extraction mechanism 31 for rotating and extracting the displacement of the truck is constructed as follows. That is, the rotation take-out mechanism 31 includes a rotation shaft 32 extended vertically and rotatably supported on the base 21, a sprocket 33 fixed to the lower end of the rotation shaft 32, and a sprocket 33 fixed to the lower end of the rotation shaft 32.
The chain 34 is meshed with the chain 34. This chain 34 is disposed in parallel with the 11th correction wire 30 in an immovable state with respect to the running road surface 23. As a result, when the stand (Fijl) is towed via the wire 30,
Since the chain 34 is stationary, the sprocket 33 meshing with the chain 34 rotates the rotating shaft 32.

The rotation of the rotation shaft 32 is controlled by the rotation shaft 5 of the front jig IF.
A transmission mechanism 35 for transmitting the signal is configured as follows. That is, the transmission mechanism 35 includes a casing 36 fixed to the rear surface of the front column 24 and a casing 36 fixed to the rear surface of the front column 24.
6, a rotating shaft 37 extending laterally (towards the rear of the Mii) and rotatably supported; this rotating shaft 37 and the upper rotating shaft 3;
A pair of bevel gears 38 and 39 that interlock the two, and a connecting shaft 40 that is held rotatably relative to the intermediate support 25 and movable initially in the front-rear direction. This connecting shaft 40 is spline-coupled to the rotating shaft 37 (this engaging portion is indicated by the number 41 in FIG. 7), so that when the rotating shaft 32 is rotated, the connecting shaft 40 is also rotated. It turns out. Of course, the rotating shaft 37 and the connecting shaft 40 are
It is set up to be located at.

The connecting shaft 40 is connected to the rotating shaft 5 of the front jig IF.
be disengaged. That is, as shown in FIGS. 10 to 12, a seven-shaped connecting portion 5b is formed at the tip of the front jig IF rotating shaft 5, while a seven-shaped connecting portion 5b is formed at the end of the connecting shaft 40. 1
As shown in FIG.
a is formed. Therefore, for example, by sliding the connecting shaft 40 via the rod 43 by a pneumatic cylinder 42, the box portion 40a (engaging recess 40c) and the connecting portion 5b are engaged and disengaged, and when they are engaged, they are connected. The shaft 40 and the rotating shaft 5 are allowed to rotate together. In addition,
As shown in FIG. 1O, the rod 43 is attached to a connecting shaft 40.
It is fitted into an annular groove 40b formed on the outer periphery of the box part 40a so as not to impede the rotation of the box part 40a.

With the above configuration, by lowering the body W relative to the trolley while the connecting shaft 40 is displaced to the right in FIG.
It is rotatably supported by intermediate struts 26 and 27 in an immovable state in the front-rear direction. After this, the connecting shaft 40 (associating tL four places 40c) is connected to the rotating shaft 5 (the connecting portion 5 of the front jig IF)
b. As a result, when the trolley is pulled via the wire 30, the body W moves along the predetermined horizontal axis β in the middle 6
+ It will be strained and rotated. Incidentally, the body W may be removed from the trolley [2] by following the reverse procedure to the above-described procedure.

(Effects of the Invention) As is clear from the above, the present invention provides a coated surface with even better mortarability if the thickness of the coating is the same. It is possible to prevent the paint from swelling up at the boundary.

[Brief explanation of the drawing]

FIG. 1 is an overall culm diagram showing one embodiment of the present invention. FIG. 2 is a diagram showing a state in which the posture of an automobile body as an object to be coated changes as it rotates. Figures 3 and 4 are graphs showing the relationship between paint thickness and sag, painted surface smoothness, and rotation; Figures 5 and 6 are for rotating the body. The perspective view which shows the example of the jig used. FIG. 7 is a side view showing an example of a body transport trolley in which the body can be rotated. FIG. 8 is a partially cutaway plan view showing the state below the running path of the bogie. FIG. 9 is a sectional view taken along the line X9-X9 in FIG. FIG. 10 is a side cross-sectional view showing the joint portion between the rotating jig and the truck. FIG. 11 is a sectional view taken along the line X1l-Xll in FIG. 10. FIG. 12 is a plan view of FIG. 11. FIG. 13 is a sectional view taken along the line X I 3-X I 3 in FIG. 10. FIG. 14 is a sectional view taken along the line XI4-XI4 in FIG. 10<7). FIG. 15 is a plan view of FIG. 14. FIG. 16 is a small view showing how paint is being sprayed horizontally. Figure 17 is a small diagram showing how paint is being sprayed on the f side. P1 to P4: [Culm W: Body (object to be coated) β: Rotation axis [): Transport trolley IF, IR: Rotation jig 61: Lateral surface 61a: Boundary part 61b: Other parts 61A: Paint (horizontal ) : Elevation: Paint (Elevation) : Paint gun (Horizontal) : Paint gun (Elevation) : Masking board

Claims (1)

[Claims] (1) Coating comprising a painting process of applying paint by spraying to a horizontal surface extending in the horizontal direction and an vertical surface extending in the vertical direction of the object to be coated, and a drying process of drying the applied paint. In the method, the paint is sprayed onto the lateral surface so that the boundary portion of the lateral surface near the vertical surface is thin, and the thickness of the other portions other than the boundary portion is greater than the sag limit. , the paint is sprayed onto the vertical surface so that the thickness exceeds the sag limit while allowing overspray to the boundary, and in the drying step, the paint applied to the object is prevented from sagging. A coating method characterized in that the object to be coated is rotated around a substantially horizontal axis until the coating is completely cured.