JP2008043870A - Coating system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating system for repair, which enables a smooth and stepwise formation of a coating film thickness from the center to a gradation part even by using a water based paint having a high viscosity, and enables a coating film drying with a high efficiency without requiring an ambitious equipment and cost, and enables even an inexperienced worker to carry out a coating of a high quality at short times. <P>SOLUTION: When a spray gun 1 used in a coating step, a part of the coating system, is pulled to a gripper 8 side gripping a trigger portion 34, a valve part 16 departs from a valve seat portion 15 and starts to open. Since an air limiting portion 18 is provided on the valve part 16, even if the valve part 16 starts to open and a large air pressure is applied, the pressure is timely reduced, which is extremely convenient to the coating in a half-clutch state. In a drying step, a heater pipe is provided by a predetermined distance apart from a coating surface of the water based paint, and the coating surface is heated by the heater pipe discharging a heat quantity containing a predetermined wavelength band for a predetermined time, and thereafter, is exposed to the wind by a fan as the heat is being generated for a predetermined time. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a coating system for repair, and more particularly to a coating system for repairing a damaged part such as a car body of an automobile with sheet metal or putty, in particular, using a water-based paint. is there.

In recent years, the reduction of environmentally hazardous substances has become an important issue in the global increase in global environmental protection activities. In automobile painting lines, CO _{2 that} causes global warming due to energy consumption in VOC (Volatile Organic Compounds) and paint baking ovens that cause air pollution in paints. A lot is discharged.
Until now, in general, in the repair process of automobile painting in Japan, the actual situation is that damaged parts are repaired using paints of organic solvents. From the viewpoint of the above VOC countermeasures, PRTR law (Pollutant Release and Transfer Register), fire fighting law, etc., it is necessary to take measures not only in the production lines of automobile manufacturers but also in the repair industry. ing.
Against this background, the materials used have also changed, and in the repair industry, eco-type paints with a low solvent usage rate have been used instead to reduce the use of solvents designated as specific chemicals such as xylene and toluene. Has been put on the market.

In addition, since water-based paints are beginning to be put on the market due to problems of deodorization, problems with low solvents, problems with the PRTR method described above, problems with measures against VOC, etc. With the transition of materials, it is necessary to review the work technology and work environment.
In order to deal with the above environmental problems, water-diluted paint (hereinafter simply referred to as “water-based paint” or “water-based paint”) is used instead of the conventional organic solvent-diluted paint (hereinafter simply referred to as “organic solvent-type paint”). ) Is expected to improve the paint work environment and reduce the wastewater treatment load.
However, there are various problems with using water-based paints.
The problem with the first water-based paint is that the viscosity of the paint used when spraying with a spray gun is 20 to 50 seconds / Fc in the Ford Cup method, whereas the conventional organic solvent-type paint. When the viscosity of the water-based paint is expressed by the Ford cup method, it is 10 to 18 seconds / Fc cup. As shown in FIG. For this reason, it is difficult to make the sprayed state from the spray gun uniform with a normally used spray gun, resulting in an orange peel-like skin on the painted surface, and quality problems are likely to occur.

In particular, even in the case of block painting, even if there are no problems, the skin condition during the painting process, which is indispensable for the work, will deteriorate and the blurring function will not work. The difference becomes more conspicuous.
As a second problem with water-based paints, water-based paints have high viscosity, which causes problems in painting. However, as with organic solvent-based paints, these water-based paints have a low viscosity and are easy to work with. Attempts have been made to use the paint diluted with water in order to increase the efficiency, but the evaporation speed of water, which is a solvent, is slower than that of organic solvents. Another problem arises in that a space for the preheat zone for evaporating water must be secured between the two and the equipment must be provided. Such a space in the preheat zone is difficult to provide at the repair site, and there is a problem that a water-based paint cannot be introduced because the vehicle manufacturer consumes a lot of energy.

In view of the circumstances described above, a water-based paint coating method and coating apparatus that can widen the allowable range of air-conditioning at the time of painting a water-based paint and greatly reduce the subsequent preheating process are disclosed in Japanese Patent Application Laid-Open No. 2003-251250. ) Is proposed.
The coating method of Patent Document 1 is a method of applying a water-based paint to a surface to be coated with a paint gun, and is applied to the object to be coated and the object to be coated from immediately before the application of the water-based paint to the end of the painting. The spray paint particles to be heated are irradiated with heat rays to control the solid content of the coating paint.
And the coating apparatus of the said patent document 1 WHEREIN: In the coating zone provided in the conveyance path of the to-be-coated object conveyed, the heating apparatus which heats to-be-coated object just before coating, and water-based paint with respect to to-be-coated object A coating machine equipped with a spray gun for spraying, and a hot wire heater for irradiating the spray paint particles to be coated on the surface of the object to be heated. Especially, the coating machine is provided with a plurality of coating guns. In addition, it is a gate-shaped coating machine for horizontal and vertical coating, and a hot-wire heater is installed adjacent to the front and rear of the gate-shaped coating machine.

In this way, if the heat rays are continuously irradiated immediately before painting, at the time of painting, until the end of painting, the moisture in the coating can be volatilized in the painting zone by 50% or more. In addition, since heat rays are irradiated during painting, the solid content of the paint particles can be increased even in high humidity atmosphere conditions, and the booth air conditioning can be expanded. The energy consumption required for air conditioning can be reduced.
By the way, the above-described coating method and coating apparatus of Patent Document 1 are intended for a paint line of an automobile manufacturer, and are difficult to apply in the repair industry.
That is, Patent Document 1 is installed on a painting line in a factory, but when a heating device is added to a painting gun for repair, the weight is large and it cannot withstand painting work. Because the irradiated energy is emitted from the infrared lamp, far-infrared lamp, mid-infrared lamp, halogen lamp, etc. that are heated to the object, the welding operator is not allowed to carry out the painting work by holding the spray gun. It is virtually impossible, and even if it is possible, the work environment must be inferior.
Moreover, even if block painting is possible to some extent if the spray gun can be held by hand, the blur painting operation on the curved surface is a difficult technique.

JP 2003-251250 A

The present invention has been made in view of the above circumstances, and the first object thereof is to make the spray state uniform even when a highly viscous water-based paint is used, and in particular, the block portion and the blur portion. The second purpose is to provide a large-scale installation that can easily make the drying state of the same the same, and can smoothly form the coating film thickness gradually from the central portion to the blurred portion. It is an object of the present invention to provide a coating system capable of rapidly drying a coating film with high efficiency without cost and without consuming large electric power.
A third object is to provide a coating system that can effectively contribute to the problem of environmental destruction.
The fourth object is to provide a coating system that can shorten the coating time with high quality by simplifying or standardizing the technical difficulty level even if it is an inexperienced worker. There is.

In order to achieve the above object, the invention described in claim 1
A painting system for repair using water-based paint,
A coating step in which compressed air and a high-viscosity water-based paint are mixed, the paint is atomized and applied to the surface to be coated with a spray gun on the surface to be coated with a predetermined air pressure and a predetermined ejection amount;
After a predetermined setting time and a flash-off time have elapsed from the coating step, a reflector, a heating element disposed in front of the reflector, and a blowing means disposed in the rear of the heating element A coating film drying apparatus provided is disposed at a predetermined distance from the coating surface to which the water-based coating is applied, and the heating element that emits heat including a predetermined wavelength castle is predetermined on the coating surface. A drying step in which heating is performed for a period of time, and then drying is performed by applying a predetermined amount of air to the coating film surface over a predetermined time by the air blowing means in a state in which the heat generation of the heating element is continued, followed by a coating step. And the drying step is repeated twice or more under the conditions according to the above conditions.

In order to achieve the above object, the invention described in claim 2
A painting system for repair using water-based paint,
A coating step in which compressed air and a high-viscosity water-based paint are mixed, the paint is atomized and applied to the surface to be coated with a spray gun on the surface to be coated with a predetermined air pressure and a predetermined ejection amount;
After a predetermined setting time and a flash-off time have elapsed from the coating step, a reflector, a heating element disposed in front of the reflector, and a blowing means disposed in the rear of the heating element A coating film drying apparatus provided is disposed at a predetermined distance from the coating surface to which the water-based coating is applied, and the heating element that emits heat including a predetermined wavelength castle is predetermined on the coating surface. A drying step in which heating is performed for a period of time, and then drying is performed by applying a predetermined amount of air to the coating surface over a predetermined period of time with the blowing means in a state in which heat generation of the heating element is continued, and a flash-off time from the coating step After the elapse of time, the air pressure and the ejection amount are adjusted appropriately with respect to the predetermined value and applied to the coating surface, and a predetermined setting time is applied from the next coating step. And after the flash-off time has elapsed, the distance, the wavelength region and the amount of heat are appropriately adjusted with respect to the predetermined value, the coating surface is heated for a predetermined time, and then the heating element continues to generate heat. Next drying step of drying by applying a predetermined amount of air to the coating film surface by a blowing means,
The coating step and the drying step are repeated twice or more.

The painting step and the drying step in the invention described in claim 3 are characterized in that they are applied to painting and drying in Prasaf painting, top coating, and clear painting.
The spray gun in the invention described in claim 4 is a coating apparatus main body provided with a compressed air supply passage for supplying compressed air and a paint supply passage for supplying paint.
A paint spray nozzle provided in the coating apparatus main body and having a spray nozzle for spraying paint;
Air pressure adjusting means for opening and closing the compressed air supply passage and adjusting the compressed air pressure;
Paint adjusting means for opening and closing the injection port and adjusting the spray amount of the paint;
With
The air pressure adjusting means includes a valve unit capable of continuously changing a cross-sectional area of the compressed air supply passage from zero to a predetermined amount, and an air restricting portion for reducing the cross-sectional area of the compressed air supply passage by a predetermined amount to reduce the pressure. The paint adjusting means and the air adjusting means are operated in conjunction with each other.

In the spray gun according to the fifth aspect of the present invention, when the trigger portion is pulled halfway, and both the air pressure adjusting means and the paint adjusting means are in a half-open state, the spray amount of the paint and the compressed air supply passage The paint adjusting means and the air pressure adjusting means are set so as to adapt the pressure, and a high-viscosity water-based paint particle having a Ford Cup seconds of 20 to 45 seconds can be sprayed uniformly. It is characterized by that.
In the spray gun according to the sixth aspect of the present invention, the spray amount of the paint continuously changes at least in the movement stage of the needle valve and the paint spray nozzle in the first half of the travel stroke by the trigger portion, and the remaining movement. In the stage, the spraying amount of the paint is set so as to be almost the same or slightly changed, and it is characterized in that the composition is suitable for the blur painting work for the paint having a high viscosity.
The drying device according to the seventh aspect of the invention can emit far-infrared rays arranged in front of a reflection partition body including a front reflector of a casing and a pair of side reflectors located at both ends of the front reflector. Heating the heater tube, irradiating the coating with the heat generation and radiation spectrum wavelength;
After the elapse of a predetermined time from the start of irradiation of the heater tube, air is blown from the blowing means, and the temperature of the coating film is cooled by about 10 ° C. to about 20 ° C. than the predetermined temperature reached by the heating. In addition, the temperature is maintained in a substantially constant state.

The heating element of the drying device in the invention described in claim 8 is set so that the temperature of the coating film surface is heated to around 60 ° C. to 70 ° C. in a state where air is blown by the blowing means, and the drying step The heating element and the air blowing means operate only the heating element for a predetermined number of seconds, and immediately after that, the heating element and the air blowing means are simultaneously operated for a predetermined number of seconds. It is a feature.
The amount of air blown by the air blowing means applied to the coating surface in the invention described in claim 9 is 35-50 liters / min, more preferably 40-44 liters / min per 1 m × 0.7 m area. It is characterized by that.
The heating element of the drying device used in the drying step according to the invention described in claim 10 emits a radiation spectrum in a wavelength range that is easily absorbed by non-ionic water or an alcohol-based solvent that is a solvent of the water-based paint. When only the heating element operates, it emits a radiation spectrum including a medium wavelength range of 2.5 μm to 4.0 μm,
When the heating element and the air blowing means are simultaneously operated, it is set to emit a radiation spectrum including a long wavelength region of 5.5 μm to 11 μm.
The heating element of the drying device used in the drying step according to the invention described in claim 11 is:
Nichrome wire is accommodated in the center of the copper tube, and the surface of the copper tube is coated with nickel.

According to the invention of claim 1,
A painting system for repair using water-based paint,
A coating step in which compressed air and a high-viscosity water-based paint are mixed, the paint is atomized and applied to the surface to be coated with a spray gun on the surface to be coated with a predetermined air pressure and a predetermined ejection amount;
After a predetermined setting time and a flash-off time have elapsed from the coating step, a reflector, a heating element disposed in front of the reflector, and a blowing means disposed in the rear of the heating element A coating film drying device provided is disposed at a predetermined distance from the coating surface to which the water-based coating is applied, and the heating element that generates heat including a predetermined wavelength castle is predetermined on the coating surface. A drying step in which drying is performed by applying a predetermined amount of air to the coating surface over a predetermined time by the blowing means in a state in which the heating element continues to generate heat, and then a coating step. Since the drying step is repeated twice or more under the conditions according to the above conditions, the sprayed state can be made uniform even when using a highly viscous water-based paint that is difficult to paint. Border with painted surface Fading and blurring are extremely easy to perform, and in particular, the dryness and fineness of the blurred surface can be made the same level as the old painted surface. In addition, the coating film can be dried with high efficiency, and even for inexperienced workers, the technical difficulty of repair is simplified or standardized as much as possible, resulting in high quality and shortening of painting time. It is possible to provide a coating system that can contribute to the suppression of environmental destruction.

According to the invention described in claim 2, a coating system for repair using a water-based paint,
A coating step in which compressed air and a high-viscosity water-based paint are mixed, the paint is atomized and applied to the surface to be coated with a spray gun on the surface to be coated with a predetermined air pressure and a predetermined ejection amount;
After a predetermined setting time and a flash-off time have elapsed from the coating step, a reflector, a heating element disposed in front of the reflector, and a blowing means disposed in the rear of the heating element A coating film drying apparatus provided is disposed at a predetermined distance from the coating surface to which the water-based coating is applied, and the heating element that emits heat including a predetermined wavelength castle is predetermined on the coating surface. A drying step in which heating is performed for a period of time, and then drying is performed by applying a predetermined amount of air to the coating surface over a predetermined period of time with the blowing means in a state in which heat generation of the heating element is continued, and a flash-off time from the coating step After the elapse of time, the air pressure and the ejection amount are adjusted appropriately with respect to the predetermined value and applied to the coating surface, and a predetermined setting time is applied from the next coating step. And after the flash-off time has elapsed, the distance, wavelength range, and amount of heat are appropriately adjusted with respect to the predetermined value, the coating surface is heated for a predetermined time, and then the air is blown in a state in which the heating element continues to generate heat. The next drying step of drying by applying a predetermined amount of air to the coating surface by means,
Since the coating step and the drying step are repeated twice or more, even when using a highly viscous water-based paint that is difficult to paint, the spray state can be made uniform, and the old coating surface, The blur coating is extremely easy to perform, and in particular, the dryness and miniaturization of the blurred surface can be made to the same level as the old painted surface, and there is no significant equipment cost and high power consumption. The coating can be dried twice or more with high efficiency without consuming, and even by inexperienced workers, the level of technical difficulty in repair can be simplified or standardized as much as possible. It is possible to provide a coating system capable of reducing the coating time with quality and contributing to the suppression of environmental destruction.

According to the invention of claim 3, in the invention of claim 1 or 2, it is possible to appropriately adjust at least a predetermined amount in the spray gun and the coating apparatus, and to perform a plastic coating, a top coating using a water-based paint, A coating system that can be applied to clear coating and drying can be provided.
According to the invention of claim 4, the spray gun includes a coating apparatus main body provided with a compressed air supply passage for supplying compressed air and a paint supply passage for supplying paint.
A paint spray nozzle provided in the coating apparatus main body and having a spray nozzle for spraying paint;
Air pressure adjusting means for opening and closing the compressed air supply passage and adjusting the compressed air pressure;
Paint adjusting means for opening and closing the injection port and adjusting the spray amount of the paint;
With
The air pressure adjusting means includes a valve unit capable of continuously changing the cross-sectional area of the compressed air supply passage from zero to a predetermined amount, and an air restricting unit for reducing the cross-sectional area of the compressed air supply passage by a predetermined amount to reduce the pressure. Since the paint adjusting means and the air adjusting means are operated in conjunction with each other, there is an intermediate stage range from the state in which the valve portion of the air pressure adjusting means is fully opened to the fully open state. In order to bring about a wider and more gradual pressure change than before, it is possible to adjust the pressure to match the state in which the radiation amount of the paint is reduced as a so-called half-clutch state by the paint adjusting means. It is extremely easy to perform blur coating that blurs the boundary between the coating surface, and in particular, it is possible to provide a coating system that can make the drying and fineness of the blurred surface comparable to the old painted surface.

According to a fifth aspect of the present invention, the spray gun draws the trigger portion halfway, and when both the air pressure adjusting means and the paint adjusting means are in a half-open state, the amount of the paint sprayed and the compressed air The paint adjusting means and the air pressure adjusting means are set so as to match the pressure of the supply passage, and even if it is a highly viscous water-based paint having a Ford Cup time of 20 to 45 seconds, the spray state can be easily changed. It is possible to form a uniform coating, and it is easy to form a high-quality coating film.
A possible coating system can be provided.
According to the invention of claim 6, in the spray gun, the spray amount of the paint continuously changes at least in the movement stage of the needle valve and the paint injection nozzle at least in the first half of the movement stroke by the trigger portion, In the remaining movement stage, the spray amount of paint is set to be almost the same or slightly changed, and it is suitable for blurring paint work with paint with high viscosity. Therefore, it is possible to provide a coating system that can be easily performed without learning advanced technology.

According to the seventh aspect of the present invention, the drying device is a predetermined unit disposed in front of a reflection partition body including a front reflector of the casing and a pair of side reflectors located at both ends of the front reflector. Heat the heater tube that can emit far-infrared rays including the radiation spectrum wavelength to irradiate the coating film,
After a lapse of a predetermined time from the start of irradiation of the coating surface of the heater tube, air is blown from the blowing means, and the temperature of the coating film is changed from about 10 ° C. to 20 ° C. than the predetermined temperature reached by the heat generation of the coating film. Cooling to about ℃ and keeping the temperature almost constant creates an environment that minimizes the drying time of the coating film. A coating system capable of drying the film can be provided.
According to invention of Claim 8, the heat generating body of the said drying apparatus is set so that the temperature of a coating-film surface may be heated to about 60 to 70 degreeC in the state which is blowing by the said ventilation means, In the drying step, the heating element and the blowing means are operated only for a predetermined number of seconds, and immediately after that, the heating element and the blowing means are simultaneously operated for a predetermined number of seconds. Therefore, after warming the coating film with the heat of the heating element and activating the movement of moisture and alcohol solvent molecules, the air is blown from the back of the heating element with a predetermined air volume to blow the coating film. It is possible to provide a coating system capable of maximizing the evaporation rate of moisture and solvent.

According to invention of Claim 9, the ventilation volume by the ventilation means applied to the said coating-film surface is 35-50 liter / min per area of 1 m x 0.7 m, More preferably, it is 40-44 liter / min. Since it is min, by applying radiant heat from the heating element, the activity of water / solvent molecules is activated and the polymerization bond between molecules in the paint is accelerated, and then a predetermined amount of air is blown by the blowing means. It is possible to provide a coating system capable of accelerating the evaporation rate of moisture or solvent from the coating film to the maximum.
According to the invention described in claim 10, the heating element of the drying device used in the drying step emits a radiation spectrum in a wavelength range that is easily absorbed by non-ionic water or an alcohol-based solvent that is a solvent of the water-based paint. When only the heating element operates, it emits a radiation spectrum including a medium wavelength range of 2.5 μm to 4.0 μm,
When the heating element and the air blowing means are operated simultaneously, it is set to emit a radiation spectrum including a long wavelength region of 5.5 μm to 11 μm, so that the wavelength in the middle wavelength region where the absorption density of the coating film is good A coating system capable of performing efficient drying with less heat source energy can be provided by a drying device that emits a wavelength in the long wavelength region.

According to invention of Claim 11, the heat generating body of the drying apparatus used for the said drying step is
Nichrome wire is housed in the center of the copper tube, and the surface of the copper tube is coated with nickel, so it can generate high-temperature heat and rises quickly to the high-temperature state. It is possible to provide a coating system that emits a spectral irradiance of 2 μm to 10 μm and can accelerate the evaporation rate of moisture and solvent in the coating film to the maximum.

Hereinafter, a coating system for repair according to an embodiment of the present invention will be described with reference to the accompanying drawings.
Hereinafter, a coating apparatus constituting a part of a coating system according to the present invention will be described in detail with reference to the drawings based on the embodiments.
FIG. 1 is a front center longitudinal sectional view of a portion of a coating apparatus according to a first embodiment of the present invention, and FIG. 2 is an enlarged longitudinal section of a portion of air pressure adjusting means incorporated in the coating apparatus of FIG. FIG. 3 is a front view showing an air valve in the air pressure adjusting means, in which (a) is a conventional air valve, (b) is an air valve according to the present invention, and FIG. FIG. 5 is an enlarged longitudinal sectional view of the tip side of the needle valve and the injection nozzle part incorporated in the painting apparatus of FIG. 1, and FIG. 5 is an enlarged front view of the entire needle valve of FIG.
Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS. The coating apparatus of the present invention is one embodiment, and there are various forms such as combining the present invention with an automatic low-pressure spray gun body that performs remote control, or combining with a manual spray gun. In the present embodiment, the coating apparatus is described as a spray gun. Therefore, hereinafter, the coating apparatus of the present invention is referred to as a spray gun.

First, the structure of the spray gun in the first embodiment will be described. The spray gun 1 according to the present invention is a device that mixes compressed air and paint, atomizes the paint with compressed air, and applies it to the surface to be coated.
The spray gun 1 according to the first embodiment includes a spray gun body 4 provided with a compressed air supply passage 2 for supplying compressed air and a paint supply passage 3 for supplying paint, and the spray gun body 4. A paint spray nozzle 6 having a spray nozzle 5 for spraying paint is provided, and a needle valve 7 that opens and closes the spray nozzle 5 to adjust the spray amount of the paint.
Further details will be described. The spray gun 1 formed in the shape of a small handgun is formed into a gripping portion 8 that grips the spray gun 1 and a barrel portion 9 that is provided continuously with the gripping portion 8 and has an injection port 5 that sprays paint and compressed air. Has been.
Further, a compressed air supply passage 2 through which compressed air passes from the lower portion of the gripping portion 8 to the injection port 5 is provided in the spray gun body 4.

And the air nipple 10 connected with the supply source of compressed air is provided in the lower part of the holding part 8. Further, a compressed air supply passage 2 is provided from the air nipple 10 to the upper side of the gripping portion 8, and is positioned substantially perpendicular to the gripping portion 8 near the boundary between the gripping portion 8 and the barrel portion 9. Air pressure adjusting means 11 for opening and closing the compressed air supply passage 2 is provided.
The air pressure adjusting means 11 is mounted in a bottomed mounting hole 12 formed so as to be orthogonal to the compressed air supply passage 2 of the spray gun body 4. The air pressure adjusting means 11 includes a valve seat body 14, a valve portion 16 that comes into contact with and separates from the valve seat portion 15 formed in a tapered shape of the valve seat body 14, and a small diameter on the small diameter end side of the valve portion 16. The air restricting portion 18 having a frame shape (or disk shape) continuously provided through the connecting portion 17, the spring receiver 19 continuously provided at the large-diameter end of the valve portion 16, and one end of the spring receiver 19. The coil spring 13 is fitted and the other end is in contact with the inner end of the mounting hole 12.
The valve seat body 14 is mounted on the spray body 4 by screwing the threaded portion 20 into a female threaded portion formed on the inner periphery of the opening end of the mounting hole 12.

When the valve portion 16 having a frustum shape comes into contact with the valve seat portion 15 of the valve seat body 14, the valve seat 21 is pushed rightward in FIG. Then, the valve portion 16 is separated from the valve seat portion 15 and the compressed air supply passage 2 is opened.
An air restricting portion 18 having a large diameter is continuously provided on the small diameter end portion side of the valve portion 16 via a thin connecting portion 17 and moves along the axial direction of the mounting hole 12 together with the valve portion 16. .
The valve portion 16, the connecting portion 17, the air restricting portion 18, the valve stem 21 and the spring receiver 19 are integrally formed, and are always leftward in FIG. 2 by the coil spring 13, that is, the valve seat portion at the valve portion 16. 15 is biased in the direction of closing, in other words, the direction of closing the compressed air supply passage.
The middle portion of the valve seat body 14, that is, the left side of the air restricting portion 18, has a plurality of circular holes so that air that passes through the valve seat portion 15 and is controlled by the air restricting portion 18 is discharged. In this case, four openings 22 are formed.

Further, an annular groove 23 is formed on the outermost periphery of the valve seat body 14, and an O-ring 24 is fitted in the annular groove 23, whereby the valve portion 16 is closed. In addition, the compressed air is prevented from leaking from the mounting hole 12 side to the downstream compressed air supply passage 2 from between the outer periphery of the valve seat body 14 and the inner wall of the spray gun body 4.
The diameter of the inner wall of the air chamber 25 of the valve seat body 14 is 6.8 mm, whereas the outer diameter D1 of the air restricting portion 18 is used to confirm the effect of the present invention.
D1A = 6.4mm
D1B = 6.5mm
D1C = 6.6mm
D1D = 6.7mm
These four types of prototypes were produced and subjected to a predetermined confirmation test. The dimensions of the other parts are as shown in FIG.

In addition, by using an elastic member such as resin for the valve portion 16, when the valve portion 16 closes the compressed air supply passage 2, it is possible to reliably prevent the compressed air from entering and exiting.
Above the air pressure adjusting means 11 (upper stage), a needle valve 7 and a paint spray nozzle 6 for controlling the spray of paint are disposed.
The needle valve 7 has a tapered tip 26 at one end on the injection port 5 side and a coil spring 28 via a needle valve guide 27 for controlling the movement of the needle valve 7 at the other end. is doing. The coil spring 28 is biased in a direction to close the injection port 5. Further, in front of the needle valve guide 27, a needle packing 29 for sealing paint leakage is pressed by a packing adjusting screw 30. The packing adjusting screw 30 is screwed to an appropriate strength in order to prevent paint leakage and to make the needle valve 7 operate smoothly.
A paint guide path 32 provided with a paint joint 31 connected to the paint supply source is located near the center of the needle valve 7.

Further, the end portions of the needle valve guide 27 and the valve stem 21 on the injection port 5 side have a rotation center 33 in the barrel portion 9 and abut a trigger portion 34 provided substantially parallel to the grip portion 8. . Therefore, when the trigger portion 34 is pulled toward the grip portion 8, the coil spring 13 provided on the valve seat portion 15 of the air pressure adjusting means 11 and the coil spring 28 provided on the needle valve 7 are compressed.
When the coil spring 13 provided in the air pressure adjusting means 11 is compressed, the valve portion 16 provided in the air pressure adjusting means 11 moves to the coil spring 13 side, so that the compressed air supply passage 2 is opened. Then, compressed air is supplied to the injection port 5 according to the compressed air supply passage 2 provided in the barrel part 9.
At this time, the compressed air tries to flow into the air chamber 25 side of the valve seat body 14 from the gap between the valve portion 16 of the air pressure adjusting means 11 and the valve seat portion 15 of the toilet seat body 14, but continues to the valve portion 16. The flow is restricted by a gap formed between the outer peripheral edge of the disc-shaped air restricting portion 18 provided and the inner peripheral wall of the air chamber 25. As a result, even if the gap between the valve portion 16 and the valve seat portion 15 becomes large, the flow rate is restricted by the air restricting portion 18 and the pressure in the downstream portion of the compressed air supply passage 2, in other words, from the injection port 5. The discharged air pressure is regulated to be a predetermined pressure.

In this way, when the coil spring 28 provided at the end of the needle valve 7 is compressed, the needle valve 7 slides together with the cylindrical needle valve guide 27.
Then, since the needle valve 7 that has closed the injection port 5 is withdrawn inside the injection port 5, the injection port 5 is opened and the paint is ejected.
The valve portion 16 moves slightly faster than the needle valve 7 and is designed to inject compressed air, so that compressed air is sent slightly ahead of the paint injection. The function of adjusting the pressure of compressed air will be described in detail later.
Next, the detailed structure of the tip structure of the spray gun 1 of the first embodiment will be described. FIG. 4 is an enlarged cross-sectional view of the tip of the spray gun 1, and FIG. 5 is an enlarged front view of the needle valve 7 in the spray gun 1. For convenience of explanation, the components described with reference to FIG.
First, the tip structure of the spray gun 1 will be described with reference to FIG. In the spray gun 1, an air cap 35 is screwed into the injection port 5. The air cap 35 is provided with a plurality of small holes 37a to 37d in the vicinity of the through hole 36 provided in the center, and is further away from the center of the air cap 35. A plurality of small holes 37e to 37h drilled obliquely inward are provided. The paint is mainly ejected from the through hole 36, and compressed air is ejected from the small holes 37a to 37d provided in the periphery.

The paint is diffused by the jetted compressed air. In this way, atomization by spraying a liquid is called atomization.
The paint spray nozzle 6 is located inside the through hole 36. The paint spray nozzle 6 has a first taper portion 38 having a smaller diameter as it goes from the spray port 5 toward the interior of the paint spray nozzle 6, and a second taper having a larger diameter as it goes further from the first taper portion 38 toward the inside. A portion 39 and a third taper portion 40 having a larger diameter from the second taper portion 39 toward the inside are further formed.
Further, a needle valve 7 which is a rod-shaped valve as shown in FIG. The needle valve 7 includes a tip portion 26 formed in a tapered shape, an injection amount limiting portion 41 having the same diameter continuous with the tip portion 26, and an opening / closing valve portion 42 continuing thereto. The injection amount limiting portion 41 is continuous with the tip portion 26 on the inner side of the injection nozzle 6 and has the same diameter and a predetermined length with a certain play amount (1 to 2 mm) added.

The on-off valve portion 42 has a smaller taper angle than the third taper portion 40 and has a larger diameter from the injection port 5 toward the inside of the paint injection nozzle 6.
Further, the distal end portion 26 in the first embodiment is conical, the length r of the bus bar of the distal end portion 26 forming the distal end portion 26 is 0.5 mm, and the distal end sensitivity α is 80 to 85. It is good to have a degree. In particular, when the tip angle α is 83 degrees, the coating state of the paint is greatly improved.
As shown in FIG. 1, the needle valve in the first embodiment is configured by combining a first coil spring 28a and a second coil spring 28b having different spring coefficients.
In the present embodiment, the first coil spring 28a has a lower spring coefficient than the second coil spring 28b. However, the first coil spring 28a may be a coil spring having a spring coefficient higher than that of the second coil spring 28b, or may be reversed.

The first coil spring 28 a is in contact with the needle valve guide 27, and one end of the second coil spring 28 b is connected to the first coil spring 28 a and the other end is in contact with the inner wall of the guide chamber 43. . The guide chamber 43 accommodates the proximal end side of the needle valve guide 27 and the first coil spring 28a and the second coil spring 28b.
When the trigger portion 34 is pulled with a force F from the state of FIG. 1, the first coil spring 28 a is pushed by the needle valve guide 27 slid rearward. Further, as the needle valve guide 27 slides, the force F is also transmitted to the second coil spring 28 b in contact with the inner wall of the guide chamber 43. Then, this force F is transmitted to the inner wall of the guide chamber 43, and the reaction force F ′ acts on the second coil spring 28b. Therefore, both the first coil spring 28a and the second coil spring 28b are compressed. At this time, the same force acts on the first coil spring 28a and the second coil spring 28b. However, since the elastic moduli of the two coil springs are different, in the operation up to the final stage of the trigger portion 34, The compression rate (length to be compressed) of the one coil spring 28a and the second coil spring 28b is different.

That is, the coil spring 28 in the present embodiment pulls the trigger portion 34 and mainly compresses the first coil spring 28a, and pulls the trigger portion 34 and compresses the first coil spring 28a at this stage. It is considered that the operation step is mainly performed in three stages, that is, a second stage in which the second coil spring 28b is compressed and a third stage (final stage) in which both the first coil spring 28a and the second coil spring 28b are completely compressed. be able to.
Therefore, when the first coil spring 28a is mainly compressed, only compressed air is injected, and then the second coil spring 28b is compressed halfway in addition to the first coil spring 28a. The amount of paint is restricted and the predetermined amount is injected, and when the first coil spring 28a and the second coil spring 28b are compressed to the end, the compressed air amount and the amount of paint are maximized for injection. Can be performed.
The operation from the initial stage to the middle stage of the trigger portion 34 can be called a so-called “half-clutch state” in which fine adjustment of the needle valve 7 can be easily performed with a relatively small force. It becomes possible to easily perform painting that blurs the boundary between the surface and the old painted surface.

When the trigger portion 34 is pulled, the needle valve 7 slides into the needle valve guide 27 and the spray port 5 of the paint spray nozzle 6 is opened accordingly.
More specifically, by operating the trigger portion 34, as described above, the valve portion 16 of the air pressure adjusting means 11 is opened and compressed air is injected almost simultaneously with the compression of the first coil spring 28a. The At that time, the needle valve 7 slides into the paint spray nozzle 6.
As a result, the state in which both the taper portion of the on-off valve portion 42 of the needle valve 7 and the second taper portion 39 of the paint injection nozzle 6 have been fitted properly is shifted so that there is a slight gap between the two tapers. Clearance occurs. At this time, the injection amount restriction part 41 of the needle valve 7 is located in the first taper part 38 of the paint injection nozzle 6.
At this time, when the needle valve 7 and the first coil spring 28a are in the first state described above, the compressed air starts to be injected from the injection port 5.
When the trigger portion 34 is further operated and the second coil spring 28 b starts to be compressed, the needle valve 7 further slides into the needle valve guide 27 inside the paint spray nozzle 6. Then, the clearance between the injection amount limiting part 41 and the second taper part 39 is further increased. In this state, an appropriate amount of paint and compressed air are injected from the injection port 5.

In addition, when the first coil spring 28a and the second coil spring 28b are completely compressed, the tip end portion 26 of the needle is completely accommodated inside the paint spray nozzle 6.
At this time, a maximum amount of both compressed air and paint is ejected from the ejection port 5.
Next, the spraying principle of the spray gun 1 in the first embodiment described above will be described together with an explanation of the operation.
First, when performing blur coating using the spray gun 1 according to the first embodiment, the operator holds the holding portion 8 with the injection port 5 facing the surface to be coated. At this time, the injection port 5 is located at the boundary between the old painted surface (center portion) and the surface to be painted. When the trigger portion 34 is pulled toward the gripping portion 8 against the urging force of the coil springs 13 and 28, the trigger portion 34 first comes into contact with the valve rod 21 of the air pressure adjusting means 11, and a slight delay thereof. Is brought into contact with the needle valve guide 27.
First, when the valve rod 21 of the air pressure adjusting means 11 comes into contact with the trigger portion 34, the valve portion 16 is internally passed through the valve rod 21 → the air restricting portion 18 → the connecting portion 17 in order (in FIG. 2). Move to the right). Then, the contact state between the valve portion 16 and the valve seat portion 15 is released, and the compressed air sent from below in the figure flows out to the air chamber 25 side through a gap formed between them. At this time, since the space between the inner peripheral wall of the air chamber 25 and the outer peripheral surface of the air restricting portion 18 is restricted, the pressure sent from the air compressor and introduced into the compressed air supply passage 2 of the spray gun 1 is The pressure is reduced by a predetermined amount, and the compressed air is supplied to the downstream compressed air supply passage 2 through the opening 22.

The compressed air is stably supplied with a limited pressure immediately after the valve portion 16 is opened (half-clutch state).
On the other hand, when the needle valve guide 27 comes into contact with the trigger portion 34, the needle valve 7 slides and enters the inside.
That is, the needle valve 7 that has closed the injection port 5 is pulled back into the barrel portion 9.
Along with this, the closed injection port 5 is opened.
In addition, the paint in the paint guide path 32 is ejected from the injection port 5. At this time, as described above, since the decompressed compressed air is injected slightly earlier, the paint is atomized with an appropriate amount of compressed air from the beginning.
Moreover, due to the action of the air restricting portion 18 of the air pressure adjusting means 11 of the present embodiment, the pressure is reduced from immediately after the opening operation of the valve portion 16 to a pressure suitable for blur coating, and the pressure is gradually increased according to the pulling operation of the trigger portion 34. This can improve the balance with the paint supply by the paint adjusting means.

That is, in the paint injection nozzle 6 and the needle valve 7, the second taper portion of the paint injection nozzle 6 and the injection amount restriction portion 41 of the needle valve 7 are not the same inclined surface (taper surface), but the injection amount restriction portion. Since the outer diameter of 41 is the same, even if the needle valve 7 is pulled into the paint injection nozzle 6, the gap between the second taper portion 39 and the injection amount limiting portion 41 is substantially constant.
Therefore, the compressed air supplied from the small holes 37 a, 37 b, 37 c, 37 d and the small holes 37 e, 37 f, 37 g, 37 h provided in the air cap 35 is flown by the injection amount restriction unit 41. It is possible to squirt the amount of paint commensurate with
Then, unlike the conventional case, the paint is not completely atomized immediately after the injection, and there is no possibility that the particles are injected as large particles.

The present invention is not limited to the first embodiment described above, and can be modified as follows.
That is, in the spray gun 1 of the first embodiment, the air pressure adjusting means 11 and the paint adjusting means are arranged in two upper and lower positions, but the air pressure adjusting means is on the same axis as the paint adjusting means. In this case, the needle valve and the means for opening / closing or adjusting the compressed air supply passage can be integrally configured.
By the way, according to the experiment conducted by the present inventor, in the conventional air spray gun, when the needle adjustment knob 71 is rotated twice from the fully closed state and the transformer pressure is 0.35 Mpa, The pressure is reduced to 0.22 Mpa, and when the valve portion is fully opened, the pressure is reduced to 0.18 and about half. In contrast, in the spray gun according to the present invention, when the pressure of the transformer is 0.35 Mp, the pressure is 0.3 Mpa in the half-clutch state, and remains at 0.25 in the fully opened state of the valve portion. On the other hand, it was found that there was only an opening of 0.1 Mpa, and the difference between the half-clutch and the full opening of the valve portion smoothly changed with a decrease of 0.05.

On the other hand, in the conventional air spray gun, when the half-clutch state is established from the pressure of the transformer, the pressure decreases by 0.13 Mpa, and when the half-clutch state is fully opened, the pressure decreases to 0.04 Mpa.
For this reason, in the conventional air spray gun, the width of the half-clutch state of the trigger portion is narrow, and in the process of releasing the trigger portion, the air pressure suddenly decreases, in other words, It is nothing but telling the difficulty of maintaining a half-clutch state.
On the other hand, according to the air spray gun of the first embodiment, it is very easy to change the air pressure in a so-called half-clutch state over a wide range.
Also, in the conventional spray gun, it took 115 seconds to spray 70 g of paint (solvent) when the needle valve adjustment knob was opened by 3/4 (0.75), but when it was opened 1.5 times. For example, 51 seconds and 39 seconds after two rotations are opened, and the amount of paint spraying increases rapidly here.

In other words, conventional air spray guns have the characteristic that the amount of paint spray is small at first and increases suddenly when a certain point is exceeded. If it goes, suddenly the amount of eruption will decrease.
On the other hand, according to the first embodiment of the present invention, it was confirmed that the ejection amount gradually decreased when the ejection amount was reduced from the fully open state to the half-open state.
Further, it has been clarified through experiments that the conventional spray gun has an excessively large difference in the amount of paint sprayed, and the interval over which the spray amount can be adjusted is too short, so that half-clutch operation is extremely difficult.
For this reason, in the conventional air spray gun, when coating is performed from the center portion to the blurred portion, the coating film thickness is inclined abruptly.
It is one of the techniques of blurring to apply it so as to draw a gradation well.
In order to realize such a coating film form, it is easy to perform the blurring operation so that the spray amount of the paint smoothly transitions to the full opening according to the degree to which the needle valve adjustment knob is opened.

In the first embodiment described above, the paint is ejected in a smooth shape from one rotation of the needle valve adjustment knob to full opening, and in this state, the half-clutch operation is facilitated. I mean.
In general, when blur coating is performed with an air spray gun, the center portion and the blur portion are performed in a continuous gun operation flow, which is an unavoidable operation.
While performing such a continuous gun operation, it is necessary to make the drying properties of the coating film at the center part and the blur part the same condition.
In order to solve this problem, the present inventor creates a difference between the air pressure in the half-clutch state in the blur part and the air pressure in the center part, and lowers the air pressure in the blur part from the center part, thereby reducing the drying property of the coating film. Inspired to be late.
However, when it is blurred, it is necessary to make the coating film thin and smooth, and when the coating film is applied under the same conditions (air pressure) in the same state, the drying property becomes faster. It is impossible to produce (reproduce) under the same conditions.
On the other hand, in the present invention, the function of continuously reducing the air pressure in the same flow through the spray gun operation so as to satisfy the above condition, that is, the function of continuously reducing the air pressure in the half-clutch state. Was created.

The above is the configuration and operation of an example of a spray gun (painting apparatus) used in the painting step of the painting system according to the present invention.
Next, an embodiment of a drying apparatus used in the drying step of the coating system according to the present invention will be described.
FIG. 6 is an explanatory diagram showing a schematic configuration of a drying device that constitutes a part of the coating system according to the second embodiment of the present invention, and FIG. 7 shows a configuration of a heater tube of the drying device shown in FIG. FIG. 8 is a front view showing a configuration of main parts such as a casing, a reflective partition, and a heater tube of the drying apparatus according to the second embodiment. FIG. 9 is a main view of the drying apparatus shown in FIG. 10 is a schematic cross-sectional view as seen from above, and FIG. 10 is a schematic cross-sectional view as seen from the side of the structure of the main part such as the casing, reflection partition and heater tube of the drying apparatus shown in FIG. 11 is a rear view showing a state in which the housing according to the second embodiment is attached to the movable stand.

With reference to FIGS. 6-11, one Embodiment of the drying apparatus of the coating film used for the coating system of this invention is described.
Reference numeral 110 denotes a housing having a rectangular front shape, and includes a trapezoidal portion 110a that expands forward and a rectangular portion 110b that has a rectangular shape when viewed from the side. Inside the housing 110, a cover member 114 having a depth widened forward to accommodate a plurality (three) of reflective partition bodies 112, and a fixed piece (not shown) with respect to a predetermined position in the cover member 114 Are provided with a plurality of reflecting partitions 112 that are fixed while forming a ventilation space (required air blowing space or air blowing gap) 118 at a predetermined interval. Reference numeral 116 denotes a rectifying plate provided in the vicinity of the outlet of the ventilation space 118, and functions to rectify the flow of the blown air.
Each of the plurality of reflecting partitions 112 includes a central front reflector 123, a top reflector 124, a bottom reflector 126, and front reflections (hereinafter, these three reflectors are collectively referred to as “front reflector 122”). It is composed of a pair of side reflectors 128 positioned at both ends of the body 122. The upper surface reflector 124, the lower surface reflector 126, and the pair of side surface reflectors 128 are inclined so as to spread forward, and are configured to reflect the heat and radiation spectrum wavelengths emitted by the heater tube H to the front side. Yes. Although not shown in detail in the pair of side reflectors 128, insertion openings are formed at positions that are in the same position in contrast to each other. The pair of insertion openings (not shown) of the pair of side reflectors 128 are inserted with the terminal portions C at both ends of the heater tube H, and a ventilation space outside the pair of insertion openings (required ventilation space or required airflow space). The air gap 118 is projected.

As shown in FIG. 9, the terminal portion C of the heater tube H protrudes from an outer ventilation space (required air blowing space or air blowing gap) 118, thereby preventing an axial flow fan (air blowing means) 34 described later. It is cooled by receiving air. The heater tube H can continue to generate heat with the maximum capacity by cooling the terminal portions C at both ends, and the heat generation temperature can be raised to, for example, 600 ° C. or higher that emits far infrared rays.
Also, air is supplied to the ventilation space (required ventilation space or ventilation gap) 118 on the outer surface side of each reflection partition 112 on the back side of each reflection partition (three in this example) 112. Each reflective partition 112 serving as a blast base point area for supplying air to a coating film (not shown in the figure: for example, a coating applied to a vehicle) in front of the housing 110 while cooling the terminal portion C of each heater tube H. A large area for air blowing 136 having a predetermined depth is formed. As shown in FIGS. 9 and 10, a plurality of axial fans 134 are fixed together with the motor 138 on the rear side, that is, the back side, of the large area blowing space 136 that is the blowing base point area. A filter holding plate 144 having a plurality of intake holes 142 is provided on the rear side of each motor 138, and a dust removal filter (see FIGS. 9 and 10) 152 is fixed by the filter receiver 146. . An intake space 154 is also formed between each motor 138 and the filter 152 for dust removal.

As shown in FIG. 11, a first rotating body 162 that can be rotated with respect to a horizontal axis (not shown) is attached to the rear surface of the housing 110. , The fixed state is released, and the casing 110 can be freely rotated about the horizontal axis. The rotation of the handle 164 in the reverse direction fixes the orientation of the casing 110 about the horizontal axis. Further, a second rotating body 166 that is rotatable with respect to a vertical axis (not shown) is attached to the rear surface of the housing 110, and the second rotating body 166 is fixed by rotating the handle 168 in one direction. The state is released, and the housing 110 can freely rotate about the vertical axis, and the rotation of the handle 168 in the reverse direction fixes the orientation of the housing 110 about the vertical axis.
As shown in FIG. 11, the second rotating body 166 is rotatably connected to a support shaft fixed to the back surface of the housing 110, and the second rotating body 166 includes two parallel rotating bodies. One end of each arm 72 is connected and fixed. The other distal end side of each arm 172 is connected to the rotation shaft of the column 176 of the movable stand 174. Further, the upper end of the support arm 173 is connected to an intermediate position of each arm 172 in a rotatable state, and the lower end of the support arm 173 is vertically slid along a slide groove formed in the column 176. It is fitted so that it can move. As a result, the casing 110 can be moved up and down, and when it is set to a required height position, the lower end of the support arm 173 is configured to be fixed with, for example, a lock screw so as not to slide. The lower end of the above-mentioned column 176 is fixed to the base member 175 of the movable stand 174.

Four casters 177 are provided on the lower side of the base member 175, and the entire movable stand 174 is configured to be movable on the floor. The caster 177 is provided with a brake function, and after determining the position of the drying device, the caster 177 can be braked to hold the position.
As described above, the housing 110 can be rotated in various directions in addition to the posture shown in FIG. 11 by arbitrarily rotating the first and second rotating bodies 162 and 166, the arm 172, and the support arm 173. It is possible to set. In addition, since the caster 177 is provided in the moving stand 174, for example, the caster 177 can be freely moved on the floor surface of the painting factory, and the position of the caster 177 with respect to the coating film can be set by applying a brake. Can be fixed.
Now, a drying apparatus that can efficiently set conditions suitable for the coating film will be described. As shown in FIG. 12, it has the control part 100 which consists of CPU (central processing unit), and this control part 100 is predetermined time after the heat_generation | fever start of the heater pipe | tube H (for example, a coating film is 100 to 130 degreeC). A timekeeping unit 192 that measures the lapse of time, a numeric keypad (which may be a digital switch or a volume) 194 as an input means for inputting the distance between the casing 110 and the coating film, and an axial fan A rotation speed adjustment unit 196 that adjusts the rotation speed per unit time of 134 is connected.

In particular, the rotation speed adjustment unit 196 receives the calculation result of the control unit 100 and controls the rotation speed of the axial fan 134, so that the coating film position in front of the casing 110 (for example, a position 40 to 70 cm away) is 1.0 to. Optimal electric power is supplied to the motor 138 in order to adjust the rotational speed of the axial fan 134 so as to obtain a wind speed of 3.0 m / s, preferably 1.2 m / s or higher.
In drying, not only the wind speed but also the air volume is an important factor. That is, the air volume needs to be 35-50 liters / minute, more preferably 40-44 liters / minute, when the coated surface is 1 m × 0.7 m. And change the air volume.
The control unit 100 has an input value of the distance between the casing 110 and the coating film and the temperature of the heat generating unit 132 of the heater tube H (for example, the set temperature varies depending on the capacity of 1.1 KW or the capacity of 5.6 KW). Depending on the situation, the time required for the coating to reach 100 ° C. to 130 ° C. can be handled from the list data that records the relationship between the distance and the coating temperature recorded in the ROM table or the like provided in the control unit 100. Based on the data to be applied, heat in the absorption wavelength region is applied to the coating surface for a predetermined time. Thereafter, in a state where the heater tube H is heated, a time for starting the rotation of the axial fan 134 is set, and the time is counted. Further, the control unit 100 energizes and drives only the heater tube H for a predetermined time, and then activates the motor 138 that rotationally drives the axial fan 134, and then the timing unit 192 counts the drying time of the coating film. When the drying time is reached, the heating of the heater tube H is terminated.

  Next, the operation of the coating film drying apparatus of the second embodiment will be described. First, the operator sets the distance between the front surface of the housing 110 and a coating film (for example, a coating film applied to a vehicle) to a predetermined distance, for example, 40 cm in winter and 70 cm in summer. Depending on the capacity of the heater H to be used, for example, in the case of a capacity of 1.1 KW, in the range of 10 to 20 cm, in the case of a capacity of 5.6 KW, a scale or the like is used as a range of 45 to 70 cm. The measured value is set by inputting the measured value using the numeric keypad 94. Subsequently, the heater tube H is heated by operating a power input switch (not shown) of each heater tube H. In the heat generation of the heater tube H, for example, the maximum power is supplied so as to obtain a maximum capacity of 600 ° C. At the same time, the timer unit 192 starts timing. Thus, when the temperature of the coating film reaches, for example, 100 ° C. while giving an optimum radiation spectrum wavelength to the coating film due to the heat generated by the heater tube H, and the predetermined time elapses, the timer unit 192 counts up to the control unit 100. A signal is given, and the control part 100 gives the output which tells start-up start with respect to the rotation speed adjustment part 196. FIG. As a result, the rotation speed adjustment unit 196 instructs the motor 138 that drives the axial fan 134 to supply electric power that can supply air at a wind speed of, for example, 1.2 m / s or more at the coating film position. Start up. When the motor 138 is started and the axial fan 134 is rotated, the wind at a predetermined wind speed passes through the ventilation space (required ventilation space or ventilation gap) 118 outside each reflective partition 142 as shown in FIG. While the terminal portion C of the heater tube H is cooled, for example, air of 1.2 m / s or more is given to the coating film.

For this reason, a coating film falls to the temperature of about 60 to 70 degreeC, for example, and is maintained at the said temperature, the optimal drying conditions are set for a coating film, and drying for a shorter time is attained. Then, when the time measuring unit 192 counts the time elapsed until the coating film is dried, the control of the control unit 100 gives an output that tells the rotation speed adjusting unit 196 that the activation has ended. As a result, the rotation speed adjustment unit 196 stops the power supply to the heater pipe H, and then stops the power supply to the motor 138 to stop the rotation of the axial fan 134.
In the present embodiment, the distance between the heater tube H and the coating film is input by operating the numeric keypad 194 as an input unit. However, the present apparatus does not necessarily include the numeric keypad 194 as an input unit. This distance is not necessary, and this distance may be arbitrarily set by the operator by moving the casing (including the heater tube H) 110 together with the movable stand 174.
In the present embodiment, the terminal portions C at both ends of the heater tube H are protruded into the ventilation space 118 (required air blowing space or air blowing gap), and cooled by the air blow from the axial fan 134. The heat generating part 132 of the heater tube H can continue to generate heat at the maximum capacity, and can continue to irradiate far-infrared rays having the optimum emission spectrum wavelength, and can further reduce the drying time of the coating film. .

Further, when the temperature of the coating film reaches 100 ° C., for example, by the timing of the time measuring unit 192, the axial fan 134 is rotated to blow 1.2 m / s or more to the coating film or at an area of 1 m × 0.7 m. Is designed to reduce the temperature of the coating film to 60 ° C. to 70 ° C. and keep the temperature within a range of 10 ° by applying an air volume of 35 to 50 liters / hour. Environmental conditions can be provided, and the drying time can be further shortened.
FIG. 13 is a characteristic diagram showing the infrared absorption spectrum of water, FIG. 14 is an infrared absorption spectrum of xylene, and FIG. 15 is an infrared absorption spectrum of toluene.
In the characteristic diagrams of these infrared absorption spectra, it can be seen that there are wavelengths with low transmittance, in other words, wavelengths with high absorption (absorption peak wavelength).
This is because when a substance is irradiated with infrared light, the molecules that compose it absorb the energy of the light, and the quantized vibration or rotation changes, so that a substance is transmitted (or reflected by the substance). It is understood that the infrared ray is weaker than the irradiated infrared ray by the energy used for the transition of the molecular motion state.

Therefore, the present inventor pays attention to the infrared absorption spectrum, and when water (ionic water) is used as the solvent of the water-based paint, as shown in FIG. Therefore, the present inventors have focused on using a heating element that includes such a wavelength and emits heat in a wider wavelength band (for example, 2.5 to 11 μm).
In other words, conventionally, there has been an idea that the greater the amount of heat (temperature) in the heater tube, the more it will lead to drying, but this will increase the consumption of power energy.
Further, as can be seen from the infrared absorption spectrum of xylene, which is the solvent in FIGS. 14 and 15, and the infrared absorption spectrum of toluene, absorption peak wavelengths exist in the vicinity of 3.5 μm and 7.5 μm.
Therefore, it has been found that the heater tube may be designed so that the emission spectrum of the heater tube as a heating element includes the absorption peak of the absorption spectrum.
When the temperature rise characteristics were measured for each coating of the heater tube emitting far-infrared light, the results shown in Table 1 below were obtained.

The common place of these heater tubes is that the nichrome wire is accommodated in the copper tube.
According to the measurement results in Table 1, the “no coating” sample showed a rapid rise in temperature and the highest temperature, but the peak value of the spectral radiation characteristic was at a short wavelength, and the length was 3 μm or more. Since the irradiance is low in the wavelength range, the drying characteristics are poor. Subsequently, the coating with “Ni” had good spectral emission characteristics and was found to be the most suitable of these coatings. Furthermore, the coating with “Alumina / Iron Oxide” was followed by a high temperature, but it took a long time to obtain the prescribed amount of heat, ensuring an efficient amount of heat for drying. I can't.
It is possible to extend the effective wavelength region by increasing the heat capacity of the heater tube itself.
However, when the amount of heat is increased, there is a problem that the life is shortened.

Therefore, the present inventor has investigated a new cause that the terminal portion of the heater tube is deteriorated by heat.
That is, based on the investigation of this new cause, the above-mentioned problem was solved by cooling the terminal portion of the heater, and a heater tube having the maximum effective wavelength range was realized. This makes it possible to increase the amount of heat. For example, it is possible to increase the capacity from 1.4 kW to 1.6 kW to 1.7 kW to 1.8 kW, and to increase the effective wavelength of the heater tube. Those having an area (effective heat generation area) of 800 mm could be extended from 850 mm to 900 mm. In addition, the heater tube surface temperature of about 500 ° C. can be increased to about 100 ° C. to about 600 ° C. Therefore, the relative radiation intensity density can be greatly increased by increasing the relative radiation density of the heater tube. As a result of the above, the specifications of the heater tube are set at a capacity of 1.7 kW to 1.8 kW, a surface temperature of 550 ° C. to 600 ° C., an effective length (effective heat generation length) of 850 mm to 900 mm, and a heater density of around 5.5. enable. For this reason, it becomes possible to manufacture a heater tube having the maximum function as a drying device.
FIG. 16 is a front view showing a configuration of main parts of a drying apparatus such as a casing and a heater pipe according to the third embodiment.
As shown in FIG. 16, the surface temperature of the heater tube of this drying apparatus is shown in Table 2 as a result of measurement divided into three sections A to C in the vertical direction and five sections 1 to 5 in the horizontal direction.

According to this result, the maximum temperature is 660 ° C. in the B-3 section (center), and the minimum temperature is 630 ° C. in the section C-5 (lower right corner) and the B-1 section (left center), the average temperature. Is 641 ° C. and can be said to be a nearly uniform heat dissipation temperature distribution.
Next, the infrared drying heater that has become the basic data constituting the drying apparatus developed by the present inventors has a rating of 200 V, power consumption of 800 W, a tube diameter of 12.5 mm, a tube length of 380 mm, A nichrome wire is accommodated in a copper tube, and the surface of the copper tube is coated with 100 μm nickel. Hereinafter, this is referred to as a “standard product”. Let's call it 3.
The inventor of the present invention has no In addition to 3, various measurements were performed on the samples shown in [Table 3] below.

In Table 3 above, no. Sample No. 1 is a glass tube in which a nichrome wire is housed inside and coated with quartz.
No. In the sample No. 2, the heat generating portion is carbon, and a glass tube containing carbon is coated with quartz. No. Sample No. 3 is a standard heater tube according to the present invention, in which the surface of a copper tube containing nichrome wire is coated with nickel. No. In the sample No. 4, the heat generating part is a nichrome wire, and the surface of the glass tube is coated with quartz powder. No. Sample No. 5 has a nichrome wire housed in a ceramic tube as a heat generating portion. The sample of 3-120μ is No. In the sample No. 3, the thickness of the nickel coating film is increased to 120 μm, and the sample of 3-80 μm is No. 3. In the sample No. 3, the thickness of the nickel coating film is increased to 80 μm.

(1) First, a standard sample No. For 3 heater tubes, spectral irradiance in the range of 3.0 μm to 8.0 μm was measured using a JASCO monochromator (CT25GTM) at a position 600 mm away from the heater tube with a voltage of 200 V and a power of 780 W. The results are shown in FIG.
In FIG. 17, the horizontal axis represents wavelength (μm), and the vertical axis represents irradiance (μW / cm ² / nm). As can be seen from FIG. 17, the radiation has a peak in the vicinity of 3 μm where the absorption peak wavelength of water exists, and at a wavelength of 8 μm, it is about 20% of the peak value. Is not seen. In particular, in the vicinity of the peak of 6 μm of the absorption spectrum next to water, which is about 45% of the peak value, the most efficient drying of moisture can be performed.
Next, standard sample No. 3 using the infrared drying heater 3, the spectral irradiance when the applied power is reduced to 650 W, which is about 80% of the rating, and 500 W, which is about 60% of the rating, is turned on at the rated output (200 V, FIG. 18 shows a characteristic curve of an irradiance relative value (the rated value is assumed to be 1.00) expressed as a ratio with respect to when the power is turned on at 800 W).

The temperature of the tube of the infrared drying heater at this time is 597 ° C. when applying a rated power of 800 W, 597 ° C. when applying 650 W, and 543 ° C. when applying 500 W. The irradiance at 650 W is slightly different from around 3.1 μm and around 500 μm at 500 W, but there is almost no deviation from the absorption peak wavelength of water, so there is no effect on the drying efficiency.
Next, FIG. 19 shows the relative irradiance characteristics with respect to the sample No. 3 serving as the standard of the spectral irradiance of the various infrared drying heaters shown in Table 3.
That is, FIG. 1, No. 1 2, no. 4, no. 5 is the standard radiant irradiance when the spectral irradiance is turned on at each rated voltage. 3 is a graph showing the result of comparison with spectral irradiance at a position 600 mm away when 3 (200 V, 800 W) is lit at the rated voltage.
According to FIG. The spectral irradiance of all the samples except for No. 2 is the standard sample No. in the entire wavelength range of measurement. The level is lower than 3. Sample No. No. 2 also has a irradiance of standard sample No. at wavelengths longer than 4.2 μm. Lower than 3.

  Sample No. The irradiance of No. 1 is in the range of 3 μm to 5 μm, and the standard sample No. Although it is within 70% of 3, it increases in the wavelength region of 5 μm or more, and becomes about 90% in the vicinity of the wavelength of 7 μm. On the other hand, sample No. The irradiance of No. 2 increases sharply below 4.5 μm, and at the wavelength of 3 μm, the standard sample No. 3 or more than 3. This is considered to be due to the radiation of the carbon heating element passing through the quartz tube.

Sample No. The irradiance of No. 4 is in the range of 3 μm to 5.5 μm of standard sample No. When the wavelength is 5.5 μm or more, it increases at a wavelength of 5.5 μm or more, but it is about 70% near the wavelength of 7 μm. Sample No. Since 4 is a tungsten filament bulb, most of the radiation is concentrated at a wavelength of 20 μm or less, and it is estimated that the main component of radiation in this wavelength range is from the outer tube of the double tube. Sample No. The irradiance of No. 5 is a standard sample No. 3 at a wavelength of 3 μm. No. 3 is 30% or less, but at 5.5 μm, the standard sample no. It increases to about 80% of 3, and reaches about 90% at a wavelength of 7 μm or more. However, sample no. The rise of 5 is very bad, and it takes 20 minutes or more until the irradiance reaches the maximum, so it is not suitable for a drying apparatus.
As described above, for the various infrared drying heaters shown in FIG. According to the measurement of the relative irradiance characteristics with respect to No. 3, the standard sample No. If it is 3, the movement of the molecule | numerator in a water-based coating material can be activated, and the polymerization bond of the molecules in a coating material can be accelerated.
Sample No. 2 in the region of 3.0 μm to 4.2 μm. Spectral irradiance much higher than 3 is emitted, but since the irradiance in the long wavelength region of 4.5 μm or more, which is effective for drying, is low, drying efficiency is low and it is found that there is no practicality.

In addition, increasing the irradiance (density) and increasing the radiant energy for the coating film means increasing the density of the radiant relative illuminance in the coating film of the dryer (heater). If the distance between the heater and the coating surface is reduced, the illuminance density can be increased or the capacity of the heater can be increased. However, in reality, when the distance between the heater and the painted surface is shortened, the temperature of the painted surface rises to 100 ° C or more, and the elongation of the resin / adhesive or steel plate applied to the automobile may cause trouble. It becomes a factor. In addition, increasing the heater capacity (wattage) to increase the density is an increase in electrical capacity at the factory, which can lead to considerable increases in costs for electrical equipment, etc., without increasing the electrical capacity as much as possible. It is desirable to be able to increase the efficiency of drying without making the distance too close.
Therefore, the present inventors show the results of measuring the relationship of the radiation density for each interval between the infrared drying heater and the surface to be dried, as shown in Table 4 below. Table 4 shows the standard sample No. 3 shows a relative value in which the radiation density when the distance between the heater 3 and the surface to be dried is 600 mm is 1.00.

By actually measuring the distance versus relative illuminance as shown in Table 4, the relative illuminance can be easily converted even if the distance changes. For example, sample No. If the distance of 3 approaches 500 mm, the relative illuminance becomes 1.41 times.
Next, in order to investigate the drying factor (efficiency) of the water-based paint, the cloth is moistened with water and spread on the surface of the body of the automobile, and a heater (drying device) is placed at a position 70 cm away from the surface of the cloth. The following measurement was performed in the installed state.
The purpose of this measurement is to support the water-based paint in the system of the present invention by correlating the transition of water evaporation with the evaporation of the solvent or ionic water to support the drying of the paint using wind. It is proved that it is a heater.
As a measurement (verification) method, a waste cloth (cloth) with small eyes is used, and the dryness is determined by the weight of the wetted state and the state of using the heater, and the dry tentacles.

As specific conditions,
(1) The heater is energized in advance and raised to a predetermined temperature.
(2) The distance between the heater and the waste is 70 cm.
(3) As a pattern for drying the waste 1) “Pattern 1”: a pattern in which only the heater is energized 2) “Pattern 2”: a pattern in which air is blown by a fan 30 seconds after the start of heat irradiation from the heater.

3) “Pattern 3”: a pattern in which air is blown by a fan 45 seconds after the start of irradiation from the heater 4) “pattern 4”: a pattern in which air is blown by the fan 60 seconds after the start of heat irradiation from the heater 5) “Pattern 5”: Measurement was performed by dividing the pattern into a pattern blown by a fan 90 seconds after the heat was applied from the heater.
First, Table 5 shows the actual measurement results of the evaporation amount and evaporation rate of water before and after drying when drying is performed for 7 minutes by the above five patterns in an environment of an external temperature of 24 ° C. and a humidity of 65 to 70%.

FIG. 20 shows a graph of the evaporation rate for each pattern based on Table 5 above.
As can be seen from Table 5 and FIG. 20, the pattern 3 has the best evaporation rate, and the pattern 4 has the best evaporation rate. That is, a pattern in which only the heat of a full-power heater that has reached a predetermined amount of heat is irradiated on the waste surface for 45 seconds, and then the fan is blown with a predetermined amount of air and a wind speed while the heater heat is immediately irradiated. The best results were obtained for drying. Also, even when pattern 4 is heated for 60 seconds on the waste surface only with the heat of the heater that has reached a predetermined amount of heat, and immediately after that, a predetermined amount of air and a wind speed are blown toward the waste surface by a fan. Results were obtained. The evaporation rate when the air is started 90 seconds after irradiating the waste surface with the heat of only the heater on Pattern 5 is lower than that of Pattern 3 and Pattern 4 as in the case of the heater alone. It is presumed that moisture may remain on the part or the back side.
Next, the surface temperature of the waste was measured to elucidate the dry state of the waste as described above, and the results shown in Table 6 were obtained.

A graph of Table 6 is shown in FIG.
According to FIG. 21, the highest temperature is obtained when the waste is directly irradiated with heat only from the heater of the pattern 1, and then the temperature is high when the wind is applied 45 seconds after the pattern 3.
When used at full power, the heat distribution of the heater used here rises from 65 ° C to 75 ° C in 1 to 2 minutes on a surface 60 cm away, and from 120 ° C to 6 to 7 minutes. Although it has the ability to go up to 130 ° C, in the case of a waste cloth moistened with water, the temperature rise of the water becomes much gentler, and when it is blown by a fan, the temperature once drops to around 6 minutes, then 7 minutes It can be seen that it gradually starts to rise after the lapse.
As described above, the amount of evaporation of the waste and the surface temperature were verified. Further, the present inventor peeled off the waste spread on the surface of the door (steel plate) of the automobile and confirmed the remaining amount of moisture.

First, as shown in FIG. 22, when the pattern 1 is observed, that is, when only the heater is driven and heat is applied to the waste (a), the waste is peeled off and the door surface is exposed (b). It was confirmed that moisture remained in an area of about 80% of the exposed portion.
On the other hand, as shown in FIG. 23, in pattern 3, that is, in a state (b) in which the waste is removed from the state (a) in which the air is blown by the fan 45 seconds after the heat irradiation by the heater and the door surface is exposed. As a result of the observation, it was confirmed that only about 5% of the exposed area remained with respect to the exposed part.
From the above, even if only the heat of the heater is applied for drying, only about 74% evaporates within a predetermined time, but about 90% is evaporated by making a reasonable combination of heat and wind. I can see that
In addition, it is impossible to grasp the original water evaporation state only by the weight of the object to be coated (in this case, waste), and the evaporation of water is performed only on the surface, or on the inside or the back surface. Desirable drying conditions could be derived by observing as described above.

That is, when compared with the state at the time of actual coating, there is a state in which moisture remains as a residue in the coating film and moisture scattered on the surface in a state where the steel plate is coated. It means that it will not dry unless the remainder is scattered, and it is necessary to deal with the phenomenon of moisture accumulation in this coating film. In addition, the evaporation time was shortened and a good dry state was obtained.
Next, the present inventor measured the change in weight when the “water-based saff” was naturally dried after the coating material dried for a predetermined time with the above-described drying system.

Table 7 shows the results of measuring the change in weight and film thickness after the object to be coated, which had been dried under the drying conditions of Pattern 1 to Pattern 6, was further naturally dried at 16 ° C. to 18 ° C. for 16 hours. According to Table 7, since there is almost no change over time in the weights of “System 30”, “System 45”, and “System 60” from 0 to 0.01, they have already been completely dried before entering the natural drying. This proved to be an ideal drying system. Here, as described above, the systems 30, 45, and 60 irradiate heat at the full power of the heater in advance for 30 seconds, 45 seconds, and 60 seconds, and then immediately add wind from the fan to Means that it was irradiated.
In Table 7, “Hot air” in “Pattern 1” means a state in which the heater and the fan are operated simultaneously from the beginning, and “Heat only” in “Pattern 2” means a state in which only the heat from the heater is irradiated. “Pattern only” in “Pattern 3” refers to a state in which the wind is only applied by the fan.

As can be seen from Table 7, when only the heat of the heater is applied, or when only the wind is applied, of course, when the hot air is applied only from the beginning (in the case of pattern 1), the moisture content is It became clear that a large amount remained, and even after natural drying for 16 hours, moisture remained, and it was proved that it was not suitable as a drying means.
Next, based on the coating method and the drying method verified as described above, a standard painting / drying procedure using a water-based paint will be specifically described.
First, prior to the description of the painting / drying procedure, the construction of painting a car body of an automobile will be briefly described with reference to FIG.
In FIG. 24, if the automobile body 205 is damaged due to an accident and an indented portion 201 is generated, the indented portion 201 is pushed out by hitting the back side (right side in FIG. 24) or knocking out from the back side. If it is impossible or difficult, pull it out from the front side using a drawer.

Even if such a sheet metal work is performed, the original shape is not restored. Therefore, after inserting and polishing the phasing edge 201 to remove the step between the base and the old coating film using a double action sander or the like, 202 is applied, and after drying, it is polished with a double action sander, hand-grinding paper or the like, and polished so as to have the shape of the steel plate surface before damage.
The coating system according to the present invention is a system that repairs as follows using all the materials of the water-based paint in the repair process up to the surfacer 203 and the top coat 204 after the putty treatment described above.
A. Plasaf coating steps Plasaf (intermediate coating) is applied for rust prevention, adhesion, and sealer effect. Generally, the number of coatings is 2 to 3 times. The thickness is generally about 60 to 80 microns in total.

(1) The procedure of the first coating For example, a special spray gun with a caliber of 1.4 mm, an air pressure of 0.1 to 0.25 Mpa, and a discharge rate of 3 to 4.5 rotations after the needle valve is fully closed ( Using the first embodiment or a spray gun having a similar function, coating is performed with a coating film thickness of 10 to 20 microns.
Next, the following drying operation is performed after completion of the first coating using a special dryer in which the heat amount, wavelength, air volume, and wind speed are included in the predetermined ranges as described above.
That is, as the drying device, the air velocity at a position 60 to 70 cm away from the heating element is 0.8 to 2.0 m / min, and the air flow is 35 to 50 liters / min per 1 m × 0.7 m area. The fan used shall be used.
As the heating element (heater tube), for example, a nichrome wire is enclosed in a copper tube, and the surface of the copper tube is coated with nickel of 80 μm to 120 μm, and the coating is separated by 60 cm to 70 cm within a predetermined time. A film having the ability to rise to 100 ° C. to 130 ° C. is used. The surface temperature of the heater tube is preferably a uniform heat radiation temperature distribution as shown in Table 2, for example.

Specifically, first, only the heater tube is irradiated with the coating surface for 30 seconds to 45 seconds, and the fan is immediately energized for 45 seconds to 90 seconds with the coating surface reaching 70 ° C. to 80 ° C. To do. Then, although the temperature of the coating film surface is once lowered to 50 ° C. to 60 ° C., the temperature then rises by 10 ° C. to 20 ° C. and is maintained at a substantially constant temperature.
The drying time is changed and set according to the relationship between the coating film thickness, the outside air temperature, and the humidity.
The amount of radiant heat of the heater is controlled by the distance from the heater to the coating surface. For example, when the rated capacity of the heater is 1.1 kW, 10 cm to 20 cm, and when the rated capacity of the heater is 5.6 kW, 45 cm. Although set to ˜70 cm, as described above, adjustment is made according to the coating film thickness, the outside air temperature, the humidity, and the like.

(2) The procedure for the second painting After the first painting, the second painting operation is started after a predetermined flash-off time has elapsed.
In the second coating, the spray gun is the same as the first coating, but the coating thickness is 20-30 microns, which is thicker than the first coating. Paint with care.
In the drying step, only the heater tube is first energized for 45 to 60 seconds, and then the heater tube is energized and blown by a fan for 60 to 120 seconds.
Then, during this time, the coating film surface falls to 60 ° C. to 70 ° C., and the state is substantially maintained.

(3) The third painting procedure After removing the heat from the second flash-off, the third painting is started.
The coating procedure using the spray gun is the same as described above, but the coating film thickness is 20 to 30 microns.
In this process, Prasaf is completed, so it is an operation that combines flash-off and setting.
In the drying process, the heat amount from the heater tube is irradiated for 45 seconds to 60 seconds, and then the wind of a predetermined air amount and wind speed is irradiated to the painted surface together with the heat of the heater tube by the fan for 5 minutes to 8 minutes.
The drying time needs to be adjusted slightly depending on the rated capacity of the heater. For the large heater (5.6 KW), it takes 5 minutes to 6 minutes, and for the small heater (1.1 KW), it takes about 8 minutes. .
Here, the polishing of the Prasaf uses water-resistant paper 800 to 1000, and particularly when the Prasaf is blurred, it is necessary to carefully grind it.

B. Steps for top coating (color base) Color base coating is repeated using a water-based paint until concealed.
It is necessary to change the number of paintings and the painting method according to the type of paint / painting (for example, metallic / pearl coating, 3-coat pearl coating, solit enamel, etc.). The flash-off between paintings is performed with reference to the following points.
(1) Procedure for the first coating When the coating from the coating area of 10 cm ² to about one door is assumed by the special spray gun described above, the nozzle diameter is 1.4 mm, the air pressure is 0.1 MPa to 0.25 MPa, and the discharge is performed. Set the amount to 3 to 4.5 revolutions return (return amount from fully closed) and paint.
In the drying step, only the heat amount of the heater is applied to the coating surface for 30 seconds to 45 seconds, and then the coating surface is irradiated for 45 seconds to 60 seconds together with the heat amount of the heater on the coating surface. The amount of heat is adjusted by the distance between the heater and the coating surface according to the rated capacity, temperature and humidity. For example, when the rated capacity of the heater is 1.1 KW, the distance is set to a range of 10 cm to 20 cm, and when the rated capacity is 5.6 KW, the distance is set to a range of 45 cm to 70 cm.

The wind speed is preferably 1.5 to 2.0 m / sec, and the air volume is 35 to 50 liters / minute, preferably 40 to 44 liters / minute for a coating area of 1 m × 0.7 m. The air volume is appropriate and the air volume is changed in proportion to the size of the paint area.
As the heater tube, one having a spectral irradiance in the range of 2 μm to 10 μm is used as described above.
(2) The procedure of the second coating The second coating is performed after taking heat from the first flash-off and paying attention to wetness and color concealment.
The coating thickness is 3-5 microns. The procedure of the spray gun is the same as the first time. The flash-off process is also performed in the same manner as the first time, but since the coating film is thicker than the first time, it is desirable that the drying process be somewhat larger.
The state in which the gloss of the film disappears is used as a guideline for the next process.
As a guide, the drying time for the heater alone is 45 to 60 seconds, and the irradiation time performed by adding wind to the heater is 60 to 90 seconds.

(3) Third to fourth coating procedure The coating film thickness is 3 to 5 microns. The procedure of the spray gun is the same as the first time. In any of the drying operations, the irradiation time of only the heater is 45 to 60 seconds, and the irradiation time performed by adding wind is 60 to 90 minutes.
(4) Setting procedure After the color base painting work is completed and until the final top coat clearing work, the continuous work is performed continuously in the non-setting state after the color base work is completed. That is, after the color base work is completed, the coating surface is continuously irradiated with spectral irradiance and heat including a predetermined wind (air volume and speed) and a predetermined wavelength to evaporate water and alcohol solvent to some extent. Setting is complete.
That is, first, only the heat of the heater tube is irradiated on the coating film surface for 45 to 60 seconds, and then the setting operation is performed for 3 minutes to 5 minutes with the heat amount of the heater tube along with the heat amount of the heater tube.

C. Clear painting step 1st painting Use water-based paint-type clear and apply half-coat, that is, paint with a degree of glossiness.
For example, when the painting with a spray gun assumes a painting area of about 10 cm ² to about one door of an automobile, the nozzle diameter is 1.4 mm, the air pressure is 0.1 MPa to 0.25 MPa, and the discharge amount is from the fully closed nozzle. Set to 4 to 5 revolutions, and paint so that the coating film thickness is 10 to 20 microns.
The drying procedure is the same as that described above, but it takes time to dry the coating film as it is thickened.
For example, only the heat of the heater tube is applied to the coating surface for 60 to 90 seconds, and then the air of a predetermined air volume and speed is applied for 90 seconds to 180 seconds together with the heat of the heater tube.

(2) The procedure for the second to third coating After taking heat from the first flash-off, paint in the same manner as the first. The second (or third) clear coating is the final finish, so after finishing the painting, dry the product while paying attention so that no dust or blisters are generated.
The procedure for drying is the same as described above, but the drying time is longer. For example, only the heat of the heater tube is applied to the coated surface for 2 to 3 minutes, and then the predetermined air volume, The wind of the wind speed is irradiated with the heat of the heater tube for 15 to 18 minutes.

The above is a standard procedure (manual) for performing painting and drying operations using water-based paints of each paint manufacturer. By constructing such a standard manual, even an inexperienced worker can achieve high quality and shorten the painting time.
In addition, there is a problem that the toning work when using a water-based paint is complicated and a desired color cannot be produced unless a lot of experience is gained. Here, the response to the problem is omitted.

The present invention is not limited to the above-described and illustrated embodiments, and various modifications can be made without departing from the scope of the invention.
For example, the spray gun is not limited to the one in the first embodiment, and a spray gun that is commercially available or that will be sold in the future is used as long as it satisfies the functions required for the present invention. May be.
Moreover, although this invention consists of a painting step and a drying step, for example, even if both steps are divided and it becomes independent, it is materialized as an invention.

  The coating system according to the present invention can provide optimum conditions for painting and drying, although it is a water-based paint that is extremely difficult to paint and dry compared to organic solvent-type paints. The present invention is not limited to the painting step and the drying step on the surface of the automobile described above, and can be used for the painting / drying process in repairing any equipment or member.

It is a front center longitudinal cross-sectional view of 1st Embodiment of the coating device which comprises a part of coating system of this invention. FIG. 2 is an enlarged longitudinal sectional view of a part of air pressure adjusting means incorporated in the painting apparatus of FIG. 1. It is a front view which shows the air valve in an air pressure adjustment means, among these, (a) is a conventional air valve, (b) is a front view which respectively shows the external appearance structure of the air valve which concerns on this invention. FIG. 2 is an enlarged vertical cross-sectional view of a tip side of a needle valve and an injection nozzle portion incorporated in the coating apparatus of FIG. 1. It is a front view which expands and shows the whole needle valve of FIG. It is explanatory drawing explaining the schematic structure of the drying apparatus of the coating film which concerns on the 2nd Embodiment of this invention. It is explanatory drawing explaining the structure of the heater pipe | tube which concerns on 2nd Embodiment. It is a front view which shows the structure of main parts, such as a housing | casing, a reflective division body, and a heater pipe | tube which concerns on 2nd Embodiment. It is the typical sectional view which looked at composition of principal parts, such as a case, a reflective division object, and a heater pipe concerning a 2nd embodiment from the upper part. It is typical sectional drawing which looked at the structure of principal parts, such as a housing | casing, a reflective division body, and a heater pipe | tube which concerns on 2nd Embodiment from the side. It is a rear view which shows the state which attached the housing | casing which concerns on 2nd Embodiment to the movement stand. It is a block diagram explaining the structure of the electric system with which the coating-film drying apparatus which concerns on 2nd Embodiment was equipped. It is a characteristic view showing the infrared absorption spectrum of water. It is a characteristic view showing the infrared absorption spectrum of xylene. It is a characteristic view showing the infrared absorption spectrum of toluene. It is a front view which shows the structure of the principal parts of drying apparatuses, such as a housing | casing and a heater pipe | tube, concerning the 3rd Embodiment of this invention. Spectral spectrum showing spectral irradiance in the range of 3.0 μm to 8.0 μm of a standard heater tube (sample No. 3) created and prototyped by the present inventor as a heater tube suitable for the drying apparatus according to the present invention. It is an irradiance characteristic figure. Standard sample no. Using the infrared drying heater No. 3, the spectral irradiance when the applied power is reduced to 650 W, which is 80% of the rating, and 500 W, which is 60% of the rating, is turned on with the rated output (200 V, 800 W). It is a characteristic view of the irradiance relative value (when the rated value is 1.00) with respect to when it is turned on with electric power. A heater tube (No. 1, No. 2, No. 4, No. 5) formed by applying various coatings to the heater tube, and a standard sample No. It is the spectral radiation characteristic figure which graphed the result of having compared the spectral irradiance in the position 600 mm away when 3 was lighted by rated power. It is a moisture evaporation rate comparison characteristic figure according to pattern. It is a graph of the surface temperature transition of a waste. It is explanatory drawing which shows the state (b) which peeled the waste from the state (a) which only heated the heater and irradiated the heat | fever on the waste, and exposed the door surface. It is explanatory drawing which shows the state (b) which peeled the waste from the state (a) which gave the ventilation by the fan 45 seconds after the heat irradiation by the heater, and exposed the door surface. It is a fragmentary sectional view which shows the cross-sectional structure of the repair part of the motor vehicle for demonstrating the process of the coating system which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Spray gun 2 Compressed air supply path 3 Paint supply path 4 Spray gun main body 5 Injection port 6 Paint injection nozzle 7 Needle valve 8 Grip part 9 Gun barrel part 10 Air nipple 11 Pneumatic pressure adjustment means 12 Mounting hole 13 Coil spring 14 Valve seat main body 15 Valve seat portion 16 Valve portion 17 Connection portion 18 Air restriction portion 19 Spring receiver 20 Screw portion 21 Valve rod 22 Opening portion 23 Annular groove 24 O-ring 25 Air chamber 26 Tip portion 27 Needle valve guide 28 Coil spring 28a First coil spring 28b Second coil spring 29 Needle packing 30 Packing adjustment screw 31 Paint joint 32 Paint guide path 33 Center of rotation 34 Trigger part 35 Air cap 36 Through hole 37a, 37b, 37c, 37d Small hole 37e, 37f, 37g, 37h Small hole 38 First One taper part 39 Second taper part 4 3rd taper part 41 Injection amount restriction | limiting part 42 On-off valve part 43 Guide chamber H Heater pipe C Terminal part 100 Control part 110 Housing | casing 112 Reflection division body 114 Cover member 116 Current plate 118 Ventilation space (Required ventilation space thru | or ventilation fan while)
DESCRIPTION OF SYMBOLS 122 Front reflector 123 Front center reflector 124 Upper surface reflector 126 Lower surface reflector 128 Side surface reflector 132 Heat generating part 134 Axial flow fan 136 Blower space 138 Motor 142 Intake hole 144 Filter restraining plate 146 Filter receiver 152 Filter 154 Intake space 162 First conductor 164 Handle 166 Second rotating body 168 Handle 172 Arm 173 Support arm 174 Moving stand 175 Base member 176 Column 177 Caster 192 Timekeeping part 194 Numeric keypad 196 Rotational speed adjustment part 201 Damaged fitting part 202 Putty 203 Surfacer 204 Paint 205 Car body

Claims (11)

A painting system for repair using water-based paint,
A coating step in which compressed air and a high-viscosity water-based paint are mixed, the paint is atomized and applied to the surface to be coated with a spray gun on the surface to be coated with a predetermined air pressure and a predetermined ejection amount;
After a predetermined setting time and a flash-off time have elapsed from the coating step, a reflector, a heating element disposed in front of the reflector, and a blowing means disposed in the rear of the heating element A coating film drying device provided is disposed at a predetermined distance from the coating surface to which the water-based coating is applied, and the heating element that generates heat including a predetermined wavelength castle is predetermined on the coating surface. A drying step in which drying is performed by applying a predetermined amount of air to the coating surface over a predetermined time by the blowing means in a state in which the heating element continues to generate heat, and then a coating step. A coating system, wherein the drying step is repeated twice or more under the condition according to the above condition. A painting system for repair using water-based paint,
A coating step in which compressed air and a high-viscosity water-based paint are mixed, the paint is atomized and applied to the surface to be coated with a spray gun on the surface to be coated with a predetermined air pressure and a predetermined ejection amount;
After a predetermined setting time and a flash-off time have elapsed from the coating step, a reflector, a heating element disposed in front of the reflector, and a blowing means disposed in the rear of the heating element A coating film drying apparatus provided is disposed at a predetermined distance from the coating surface to which the water-based coating is applied, and the heating element that emits heat including a predetermined wavelength castle is predetermined on the coating surface. A drying step in which heating is performed for a period of time, and then drying is performed by applying a predetermined amount of air to the coating surface over a predetermined period of time with the blowing means in a state in which heat generation of the heating element is continued, and a flash-off time from the coating step After the elapse of time, the air pressure and the ejection amount are adjusted appropriately with respect to the predetermined value and applied to the coating surface, and a predetermined setting time is applied from the next coating step. And after the flash-off time has elapsed, the distance, the wavelength region and the amount of heat are appropriately adjusted with respect to the predetermined value, the coating surface is heated for a predetermined time, and then the heating element continues to generate heat. Next drying step of drying by applying a predetermined amount of air to the coating film surface by a blowing means,
A coating system, wherein the coating step and the drying step are repeated twice or more.   3. The coating system according to claim 1, wherein the painting step and the drying step are applied to painting and drying in plush painting, top painting, and clear painting. 4. The spray gun comprises a coating apparatus main body provided with a compressed air supply passage for supplying compressed air and a paint supply passage for supplying paint;
A paint spray nozzle provided in the coating apparatus main body and having a spray nozzle for spraying paint;
Air pressure adjusting means for opening and closing the compressed air supply passage and adjusting the compressed air pressure;
Paint adjusting means for opening and closing the injection port and adjusting the spray amount of the paint;
With
The air pressure adjusting means includes a valve unit capable of continuously changing a cross-sectional area of the compressed air supply passage from zero to a predetermined amount, and an air restricting portion for reducing the cross-sectional area of the compressed air supply passage by a predetermined amount to reduce the pressure. The coating system according to claim 1, wherein the paint adjusting unit and the air adjusting unit are operated in conjunction with each other.   The spray gun draws the trigger partway halfway, and when both the air pressure adjusting means and the paint adjusting means are in a half-open state, the spray amount of the paint and the pressure of the compressed air supply passage are adapted to each other. 2. The paint adjusting means and the air pressure adjusting means are set, and a high-viscosity water-based paint particle having a Ford Cup seconds of 20 to 45 seconds can be sprayed uniformly. The coating system of any one of -4.   In the spray gun, the amount of paint sprayed continuously changes at least during the movement stage of the needle valve and the paint injection nozzle at least in the first half of the movement stroke by the trigger portion, and the paint injection quantity is almost constant in the remaining movement stages. The coating system according to any one of claims 1 to 5, wherein the coating system is set so as to be the same or slightly changed, and is suitable for blur coating operation in a paint having a large viscosity. The drying device heats a heater tube capable of emitting far-infrared rays arranged in front of a reflection partition body including a front reflector of a casing and a pair of side reflectors located at both ends of the front reflector, And irradiating the coating film with a radiation spectrum wavelength,
After the elapse of a predetermined time from the start of heat generation of the heater tube, air is blown from the blowing means, and the temperature of the coating film is cooled by about 10 ° C. to about 20 ° C. than the predetermined temperature reached by the heating. The coating system according to claim 1 or 2, wherein the temperature drop is kept constant.   The heating element of the drying device is set so that the temperature of the coating film surface is heated to around 60 ° C. to 70 ° C. while the air is blown by the blowing means, and in the drying step, the heating element and the air blowing are performed. The means is such that only the heating element is operated for a predetermined number of seconds, and immediately after that, the heating element and the air blowing means are simultaneously operated for a predetermined number of seconds. 8. The coating system according to any one of 7 and 7.   The amount of air blown by the air blowing means applied to the coating surface is 35-50 liters / min, more preferably 40-44 liters / min, per 1 m × 0.7 m area. The coating system according to any one of 2, 7, and 8. The heating element of the drying device used in the drying step emits a radiation spectrum in a wavelength range that is easily absorbed by non-ionic water or an alcohol solvent that is the solvent of the water-based paint, and only the heating element operates. Sometimes it emits a radiation spectrum that includes the mid-wavelength range of 2.5 μm to 4.0 μm,
The first, second, and seventh to ninth aspects are configured to emit a radiation spectrum including a long wavelength region of 5.5 to 11 µm when the heating element and the blowing unit are operated simultaneously. The coating system according to any one of the above. The heating element of the drying device used in the drying step is
The nichrome wire is accommodated in the central part of the copper tube, and the surface of the copper tube is coated with nickel. The repair for any one of claims 1, 2, 7 to 10, Painting system.

Images