JPH0852413A - Drying of material to be coated and device therefor - Google Patents

Abstract

PURPOSE:To uniformly and rapidly dry and cure a coating film formed on a large-sized material such as the car body of a construction machine and the precision controller, etc., interporated in the car body, without adversely affecting the controller, etc., having a low degree of heat tolerance by the drying temp., further to reduce the fuel cost and to miniaturize the equipment. CONSTITUTION:A material 8 to be coated is placed in a coating film drying furnace 1, the material 8 is moved from a furnace inlet A toward a furnace outlet C at a specified speed, the lamp 15 of an FIR irradiator 10 is turned on at the inlet A, the irradiator 10 is moved simulataneously with the material 8, the irradiator 10 is allowed to follow the material 8 at a speed lower than that of the material to dry and cure the coating film of the material 8, then the lamp 15 of the irradiator 10 is turned off, and the lamp is returned to the inlet A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large object to be coated, such as a car body of a large construction machine such as a bulldozer, a power shovel, a crane, etc., in which a precision control device is incorporated. The present invention relates to a method and an apparatus for drying an object suitable for drying and curing.

[0002]

2. Description of the Related Art In recent years, in the manufacturing process of large construction machines, the external dimensions have a width of 3 m, a height of 3.5 m and a total length of 7 m, and a weight of more than 20 tons, such as a car body such as a bulldozer or a power shovel, an engine or precision control equipment. After the interior is installed, the car body is painted and the coating film is dried.

This painting and drying process of the coating film is performed on a trolley with wheels that is moved by a tow conveyor laid on the floor.
With the car body near completion completed, the painter on the lifting device in the large paint chamber paints while continuously tracking the moving object, and then continuously moves it into the drying oven to apply the paint film. It's dried.

Further, conventionally, hot air is used to dry at a relatively low temperature of about 70 ° C. for 60 minutes or more, and then the car body sent from the drying furnace is cooled for a certain period of time and then sent to the next step. There is.

[0005]

The problem here is that the steel material used for the vehicle body such as the bulldozer and the power shovel has a thin plate thickness of 3.2 mm, and a thick steel plate has a thickness of 60 mm.
Since there is a large difference in heat capacity, it is very difficult to prevent uneven drying during drying.

In addition, synthetic rubber, various resin molded products, wiring boards for computers, etc. are used in the precision control equipment installed in the vehicle body, and these materials make it more difficult to dry the coating film. I have to. That is, the synthetic rubber, the resin molded product, and the wiring board are vulnerable to heat, and when the coating film is dried and the object temperature generally exceeds 70 to 100 ° C., there is a risk of deformation due to heat and sometimes loss of function.

On the other hand, in terms of coating film performance, not only further beautification, but in recent years, high performance has been required in terms of weather resistance, corrosion resistance, impact resistance, etc., in order to satisfy these requirements. As for the paints used, paints such as quick-drying phthalsan paints, thermosetting urea resin paints and catalytic reaction type urethane resin paints that heat-react or shorten the reaction speed have come to be used.

Therefore, even if only the coating and drying of the vehicle body is taken up, the heat absorption conditions are different, so that a significant difference occurs in the coating film performance depending on the time and temperature required for the drying, and it is difficult to take measures against it.

In addition, as described above, the precision control equipment installed in the vehicle body has an influence on the materials used when the temperature exceeds approximately 100 ° C. Therefore, it is necessary to keep the object temperature of the precision control equipment below 70 ° C. In order to do this, it was necessary to carry out the drying under the condition that the atmospheric temperature in the furnace was 100 ° C. or lower.

However, it is extremely difficult to satisfy all of these conditions, and in many cases, a hot air drying furnace is used.
The coating film was dried at a low temperature of 0 to 80 ° C. for 60 minutes or more.

However, it is still difficult to say that the original coating film performance is exhibited due to variations due to undriedness or overdrying.

Further, in the specification that the drying time is extended to 60 minutes or more at a low temperature, a long drying furnace is required, and as a result, a large occupied area is required. In addition, since the heat absorption of the material progresses and the temperature of the entire coating object rises due to the long-time drying treatment, it takes a long cooling time to cool the coating object to room temperature and send it to the next step after drying. There was also a problem that work efficiency was reduced.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a large object to be coated, such as a vehicle body of a construction machine, and an object to be coated, such as a precision control device, which is pre-installed in the vehicle body. , It can dry and cure the coating film uniformly and in a short time without adversely affecting the heat-sensitive precision control equipment etc. due to the drying temperature, further reduce fuel consumption, and further reduce the size of equipment. To provide a method.

Another object of the present invention is to provide a method for drying an object to be coated, which allows the coating film to be dried and cured more uniformly and in a short time.

Another object of the present invention is to provide a method for drying an object to be coated which can be used for small lot production of various kinds.

Another object of the present invention is to provide a drying apparatus for an object to be coated, which can accurately carry out the method for drying an object to be coated according to the present invention.

Further, another object of the present invention is to provide a drying apparatus for an object to be coated, which is capable of uniformly drying the object to be treated.

[0018] Another object of the present invention is to provide a drying apparatus for a coated object which can further reduce fuel consumption and increase efficiency.

[0019]

In order to achieve the above object, in the method for drying an article to be coated of the present invention, the article to be coated is put in a coating film drying oven, and the article is unloaded from the oven loading section. Moving at a predetermined speed toward the section, lighting the lamp of the near-infrared irradiation device in the furnace loading section and starting the near-infrared irradiation device at the same time as the object to be coated, and moving the near-infrared irradiation device to the object to be coated. After the coating film of the coating object is dried and cured at a speed slower than the speed, the lamp of the near-infrared irradiation device is turned off, and then sent to the furnace body loading section.

In order to achieve the above object, in the method for drying an article to be coated of the present invention, the article to be coated is placed in a coating film drying oven in a hot air atmosphere, and the article is irradiated with near infrared rays in a hot air atmosphere. It is something that is done.

In order to achieve the above object, in the method for drying an article to be coated of the present invention, the following speed of the near infrared ray irradiation device with respect to the moving speed of the article to be coated is adjusted according to the kind of the article to be coated. It is the one.

Further, in order to achieve the above-mentioned object, in the drying apparatus for a coated object of the present invention, a coating film drying oven equipped with a near-infrared irradiation device and an article to be coated are mounted and can be moved in the coating film drying oven. And a carriage moving means for moving the carriage at a predetermined speed from the furnace body loading section of the coating film drying furnace toward the furnace body unloading section, and the near-infrared irradiation device for the furnace body loading section and the furnace. Near-infrared irradiation device moving means for moving back and forth between the body carry-out parts, and lighting the lamp of the near-infrared irradiation device at the furnace body carry-in part and starting the near-infrared irradiation device at the same time as the carriage, and more than the moving speed of the carriage. Equipped with a control device for causing the near-infrared irradiation device to follow the trolley at a slow speed, and turning off the lamp of the near-infrared irradiation device at the furnace unloading part and forwarding the near-infrared irradiation device to the furnace loading part. It is a thing.

Further, in order to achieve the above-mentioned object, in the drying apparatus for an object to be coated of the present invention, the near-infrared irradiation device is a panel formed in a gate shape when viewed from the front, and inside and ceilings of both side plates of this panel. The reflector is attached to the inside of the plate, and the lamp is attached to the inside of each reflector.

Further, in order to achieve the above object, in the apparatus for drying an object to be coated of the present invention, the coating film drying furnace is equipped with a near-infrared irradiation device and a hot air supply device.

In order to achieve the above object, in the apparatus for drying an object to be coated according to the present invention, the hot air supply device takes in the used hot air in the coating film drying furnace and regenerates it into the coating film drying furnace. It is equipped with a hot air circulation system for supply.

[0026]

In the method for drying an article to be coated of the present invention, the article to be coated is placed in a coating film drying oven, and the article to be coated is moved at a predetermined speed from the furnace body loading section to the furnace body unloading section. On the other hand, the lamp of the near-infrared irradiation device is turned on at the furnace body loading section.

Further, the near infrared ray irradiation device is started simultaneously with the object to be coated, and the near infrared ray irradiation device is made to follow the object to be coated at a speed lower than the moving speed of the object to be coated. Then, after the coating film of the coating object is dried and cured, the lamp of the near-infrared irradiation device is turned off, and then it is sent to the furnace body loading section.

As described above, in the method for drying an object to be coated of the present invention, the object to be coated is irradiated with near infrared rays to dry the coating film. As a result of the experiment, the wavelength peak is 1.2 to 1.5μ.
The near-infrared rays of m have good permeability to the coating film, and are absorbed at the interface between the coating film and the metal material of the object to be coated, and the interface temperature rises rapidly.
It has been found that good drying treatment can be performed from the inside of the coating film.

Further, in the present invention, the lamp of the near-infrared irradiation device is turned on, the near-infrared irradiation device and the object to be coated are simultaneously started, and further, they are made to follow at a speed slower than the moving speed of the object to be coated in the near-infrared irradiation device. . Therefore, the coating film can be satisfactorily dried by irradiation with near infrared rays for a relatively short time.

As described above, since the near-infrared irradiation device can be moved to follow the object to be coated and the near-infrared irradiation time can be secured relatively long, the drying treatment can be performed in a short time by the high-temperature near-infrared irradiation. It is possible to dry in a short time at a low temperature of 70 ° C or less,
Therefore, for example, even if the vehicle body with a large variation in wall thickness such as a bulldozer or a power shovel and the precision control equipment that is weak to heat are integrated, the precision control equipment does not have an adverse effect due to heat, Each coating film can be dried satisfactorily and in a short time.

Further, since the coating film can be dried at a low drying temperature in a short time, the coating film drying furnace can be downsized, and the temperature of the entire coated object can be increased with the long-time drying treatment. It is possible to eliminate the rising problem.

In addition, in the method for drying an object to be coated of the present invention, a relatively long near-infrared ray irradiation time can be secured by moving the object to be coated so that the near-infrared ray irradiating device moves, and therefore the near-infrared ray actual irradiation is performed. The time can be shortened, and after drying and curing the coating film of the coated object, the lamp of the near infrared irradiation device is turned off and it is sent to the furnace body loading section, which reduces fuel consumption. You can

Further, in the method for drying an object to be coated of the present invention, the object to be coated is put in a coating film drying oven in a hot air atmosphere and then irradiated with near infrared rays to dry the film to be coated. . In this way, by using hot air and near infrared rays together in the drying treatment of the coating film, the hot air prevents overheating of the coating surface temperature due to the irradiation of near infrared rays, and the coating film can be dried in a shorter time, and better It becomes possible to carry out a drying process.

Further, in the method for drying an object to be coated of the present invention, the following speed of the near infrared ray irradiation device with respect to the moving speed of the object to be coated is adjusted depending on the kind of the object to be coated.

Generally, since the heat capacity changes depending on the thickness of the object to be coated, the following time of the near-infrared irradiation device with respect to the moving speed of the object to be coated is changed depending on the type of the object to be coated to dry the object to be coated with an appropriate drying time. Since it can be processed, it is possible to immediately cope with high-mix low-volume production.

By the way, the apparatus for drying an object to be coated according to the present invention comprises a coating film drying furnace, a near infrared ray irradiation device, a carriage for mounting the object to be coated, a carriage moving means, and a near infrared ray irradiation apparatus moving means,
Equipped with these control devices. Therefore, the control device turns on the lamp of the near-infrared irradiation device and moves the near-infrared irradiation device to the coating object when the trolley carrying the coating object moves to the furnace loading section of the coating film drying furnace. Simultaneously launching toward the furnace unloading part together with the mounted dolly, and causing the dolly to follow the near-infrared irradiation device at a speed slower than the moving speed of the dolly, and irradiate the object to be coated on the dolly with near-infrared light.

As a result, the coating film of the object to be coated on the carriage is heated from the inside by the near infrared rays and dried.

After that, when the carriage carrying the object to be coated reaches the furnace body unloading section, the control device turns off the lamp of the near infrared ray irradiating apparatus, and also sends the near infrared ray irradiating apparatus to the furnace body loading section, Wait for the next trolley with the object to be loaded.

With the above operations, the apparatus for drying an article to be coated according to the present invention can accurately carry out the method for drying an article to be coated according to the present invention.

Further, in the apparatus for drying an article to be coated of the present invention, the near-infrared irradiation device is attached to a panel formed in a gate shape when viewed from the front, inside both side plates of this panel and inside the ceiling plate. It is configured by including a reflector and a lamp attached inside each reflector. In this way, the panel of the near-infrared irradiation device is formed in a gate shape, and since the lamp is mounted on this panel, the object on the dolly is irradiated with near-infrared light from the periphery except its bottom surface almost uniformly, The coating film can be uniformly dried.

Moreover, since the reflectors are attached to the inside of both side plates of the panel and the inside of the ceiling plate, and the lamp is attached to the inside of the reflector, near-infrared rays are efficiently and more efficiently applied to the object to be coated on the carriage. It can be irradiated evenly.

Further, in the apparatus for drying an object to be coated of the present invention, the coating film drying furnace is equipped with a hot-air supply device in addition to the near-infrared irradiation device. Thus, by using the near infrared rays and hot air together, the coating film of the object to be coated on the trolley can be more uniformly and satisfactorily dried in a short time.

Further, in the apparatus for drying an article to be coated of the present invention, the hot air supply device is provided with a hot air circulation system for taking in the used hot air in the coating film drying furnace, regenerating it and supplying it to the coating film drying furnace. are doing. With this, hot air can be circulated between the hot air supply device and the coating film drying furnace to be used, so that fuel consumption can be further reduced and efficiency can be improved.

[0044]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show an example of an apparatus for carrying out the method for drying an article to be coated according to the present invention. FIG. 1 is a vertical sectional side view, FIG. 2 is a vertical sectional front view, and FIG. It is a figure. FIG. 4 is an explanatory view of specifications for obtaining a calculation formula of the near-infrared irradiation time from the moving speed of the coated object mounted on the dolly and the moving speed of the near-infrared irradiating device, and FIG. 5 is mounted on the dolly. It is a graph which shows the moving speed of the to-be-coated object, the moving speed of a near-infrared irradiation device, and the near-infrared irradiation time.

First, the drying apparatus of the embodiment shown in FIGS. 1 to 3 comprises a coating film drying furnace 1, a dolly 4 on which an article 8 to be coated is mounted, a first tow conveyor 9 as a dolly moving means, It is equipped with a near-infrared irradiation device 10, a second tow conveyor 27 that is a means for moving the near-infrared irradiation device, a control device 35 for these, and a hot air supply device 36.

As shown in FIGS. 1 and 3, the coating film drying furnace 1 has a furnace body carry-in section A, a furnace body effective section B, and a furnace body carry-out section C. Air curtains 2 and 3 are installed at the furnace body carry-in section A and the furnace body carry-out section C to prevent heat in the furnace from flowing out to prevent the temperature inside the furnace from lowering.

The carriage 4 is, as shown in FIGS.
The trolley body 5, the wheels 6, the tow (not shown), and the first and second contact portions 16 provided on the near-infrared irradiation device 10.
17 and a striker (not shown) for hitting them. The dolly 4 has a dolly body 5 on which the article to be coated 8 is mounted, and the rail body 7 is passed through the furnace body loading section A, the furnace body effective section B, and the furnace body unloading section C of the coating film drying furnace 1. It is configured to be movable to the next process. The article 8 to be treated in this embodiment is, for example, the body of a large construction machine such as a bulldozer, a power shovel, or a crane, and an engine or precision control equipment previously incorporated therein.

The first tow conveyor 9 serving as the carriage moving means is composed of a chain conveyor having an attachment (neither is shown) provided on the carriage 4 for engaging the tow. Direction, and the article to be coated 8 mounted on the carriage 4 is moved into the furnace body loading section A of the coating film drying furnace 1.
The furnace body effective portion B and the furnace body carry-out portion C are conveyed to the next step.

The near-infrared irradiation device 10 is shown in FIGS.
As shown in, the panel 11, the wheel 12, and the reflector 13
Lamp 15, the first and second contact portions 16 and 17,
The rail 18 and the tow (not shown) are provided. The panel 11 has a skeleton and an outer plate as shown in FIG.
It is gate-shaped when viewed from the front.

The skeleton is made of steel such as angles or channels. As the outer plate, a metal plate such as an iron plate, an aluminum plate, or a stainless plate that is easy to process is used. The wheels 12 are provided on both side portions and front and rear portions of the lower portion of the panel 11.

As can be seen from FIGS. 1 and 2, a plurality of the reflectors 13 are attached side by side inside the side plates of the panel 11 and inside the ceiling plate. Each reflector 13 is
It is formed of, for example, an Altite steel plate that is easy to process and has a large reflection effect, and this Altite steel plate or the like is used after being mirror-finished. In this embodiment, three lamps 15 are attached to each reflecting plate 13 via a receptacle 14.

The first and second contact portions 16 and 17 are attached to the inside of the lower part of one side plate of the panel 11 at a predetermined interval, and the truck 4 has entered the furnace body loading section A. The striker strikes the first contact portion 16, and the striker of the truck 4 passing through the furnace body carry-out portion C strikes the second contact portion 17.

The rails 18 are laid in parallel on the floor surface of the coating film drying furnace 1, and the wheels 12 provided on the panel 11 are mounted on the rails 18. Hard stoppers 19 and 2 for panels are provided at front and rear portions of the rail 18.
0 is provided.

One of the hard stoppers 19 is the furnace body carry-out section C.
The near-infrared irradiation device 10 that has moved toward the furnace body carry-in section A is stopped at a predetermined position, and the other hard stopper 20 moves from the furnace body carry-in section A toward the furnace body carry-out section C. The near-infrared irradiation device 10 is prevented from running away. The tow is attached to both sides of the lower part of the panel 11 so that it can be engaged with a second tow conveyor which is a means for moving the near infrared ray irradiation device.

The near-infrared irradiation device 10 is turned on by the lamp 15 when the first contact portion 16 is struck by the striker provided on the carriage 4 at the furnace body loading portion A, and the furnace is moved along the rail 18. When the moving operation is performed toward the body carrying-out section C, and the second contact portion 17 is struck at the furnace body carrying-out section C by the striker, the lamp 15 is turned off and the rail 18 is moved to the furnace body carrying-in section A. It is designed to be moved toward you.

The lamp 15 of the near-infrared irradiation device 10 is connected to a power source 23 through a heat-resistant cable 21 and a cable 22 in which the heat-resistant cable 21 is assembled. This power supply 2
3 is provided with the switch 24 shown in FIG. The middle of the cable 22 is taken up by a cable take-up device 26, and each lamp 1 is taken up by a cable guide 25.
Guided by 5.

The second means for moving the near infrared ray irradiation device
As shown in FIGS. 2 and 3, the tow conveyor 27 of
A drive device 28, a drive sprocket wheel 32 connected to the drive device 28, which is installed on the furnace body unloading section C side, and a driven sprocket wheel 33, which is installed on the furnace body loading section A side at a predetermined interval from the drive sprocket wheel 32, And a chain 34 having an attachment (not shown) that is bridged between the driven and driven sprocket wheels 32 and 33 and that engages with the tow.

The drive device 28, as shown in FIG.
Reversible motor 29, forward / reverse switching unit 30, and reduction unit 31
And have. And this second tow conveyor 27
When the reversible motor 29 of the drive device 28 is switched to the forward rotation side, the near infrared ray irradiation device 10 is transmitted through the drive sprocket wheel 32, the driven sprocket wheel 33, the chain 34, the attachment and the tow transmission system.
Is moved to the furnace body carry-in section A, the furnace body effective section B, and the furnace body carry-out section C, and when the reversible motor 29 is switched to the reverse rotation side, the near infrared ray irradiation device 10 is moved to the furnace body carry-out section via the transmission system. C, the furnace body effective portion B, and the furnace body carry-in portion A are configured to be moved.

The control device 35 has the following functions in this embodiment.

When the truck 4 enters the furnace body loading section A and the striker provided on the truck 4 strikes the first contact portion 16 provided on the panel 11 of the near-infrared irradiation device 10, A switch 24 for power supply is turned on by a signal from the first contact portion 16, the power supply 23 is turned on, the lamp 15 of the near-infrared irradiation device 10 is turned on, and a drive device 28 for the second tow conveyor 27. The forward / reverse switching unit 30 is switched to the normal rotation side, the reversible motor 29 is driven to the normal rotation side, and the near-infrared irradiation device 10 is furnace-carrying-in unit A at the furnace loading section A through the second tow conveyor 27. The vehicle is controlled to move toward the body carrying-out section C and to follow the carriage 4 at a speed slower than the movement speed of the carriage 4.

The dolly 4 moves to the furnace body unloading section C, and the striker provided on the dolly 4 causes the near-infrared irradiation device 1 to move.
When the second contact portion 17 provided on the panel 11 of 0 is struck, the signal from the second contact portion 17 operates the switch 24 for the power source to turn off the power source 23 to close the near infrared rays. The lamp 15 of the irradiation device 10 is turned off, the forward / reverse switching unit 30 of the drive device 28 of the second tow conveyor 27 is switched to the reverse rotation side, the reversible motor 29 is driven to the reverse rotation side, and the second tow conveyor 27 is moved. The near-infrared irradiation device 10 is controlled to be fed from the furnace body carry-out section C to a predetermined position in the furnace body carry-in section A via the via.

When the type of the article 8 to be dried on the coating film is changed, the near-infrared irradiation time previously obtained by an experiment is input and stored through an input device such as a keyboard, and the near-infrared irradiation time is stored. Based on the above, the near-infrared irradiation device outputs to the deceleration unit 31 of the drive unit 28 of the second tow conveyor 27 and moves with respect to the moving speed of the carriage 4 when moving from the furnace body loading unit A toward the furnace body unloading unit C. Control the following speed of 10.

As shown in FIGS. 1 and 2, the hot air supply device 36 includes a hot air generator 37, a hot air supply duct 38, and a hot air supply duct 38.
A hot air circulation duct 39 and a circulation fan 40 are provided. The hot air generator 37 generates hot air and sends it to the hot air supply duct 38.

The hot air supply duct 38 distributes and supplies the hot air so that the furnace body effective portion B has a substantially uniform hot air atmosphere. The hot air circulation duct 39 is used in the coating film drying furnace 1
The hot air used in step 3 is taken in and sent to the circulation fan 40.

The circulating fan 40 purifies the used hot air by the filter 41 and sends it to the hot air generator 37.

Next, an example of the drying method of the present invention will be described with reference to the operation of the drying apparatus of the above embodiment.

First, the hot air generator 37 of the hot air supply device 36
To generate hot air and supply the hot air into the coating film drying furnace 1 through the hot air supply duct 38 to form the furnace body effective portion B in a substantially uniform hot air atmosphere. Further, the air curtain 2 installed in the furnace body loading section A and the air curtain 3 installed in the furnace body unloading section C are operated to prevent the temperature inside the furnace from decreasing.

In the initial state, the near-infrared irradiation device 10 stands by at the furnace loading section A. In this state, the lamp 15 of the near infrared ray irradiation device 10 is off.

On the other hand, the article 8 to be coated is mounted on the carriage 4 outside the coating film drying furnace 1. Then, the carriage 4 carrying the article 8 to be coated is carried into the coating film drying furnace 1 by the first tow conveyor 9.

The article 8 to be coated is mounted on the carriage 4 and is intermittently fed into the coating film drying furnace 1 by an arbitrary transport tact.

When the dolly 4 carrying the article to be coated 8 enters into the furnace body loading section A, the striker provided on the dolly 4 is provided on the panel 11 of the near-infrared irradiating device 10 on standby. The first contact portion 16 is approached and is hit.

Further, the carriage 4 moves along the rail 7 toward the furnace body unloading section C at a predetermined constant moving speed.

As described above, when the striker provided on the carriage 4 strikes the first contact portion 16 provided on the panel 11 of the near infrared ray irradiation device 10, the control device is operated from the first contact portion 16. A signal is sent to 35.

Therefore, the control device 35 turns on the power supply switch 24, turns on the power supply 23, and turns on the lamp 15 of the near-infrared irradiation device 10. At the same time, the control device 35 switches the forward / reverse switching unit 30 of the drive device 28 of the second tow conveyor 27 to the normal rotation side, drives the reversible motor 29 to the normal rotation side, and drives the second device via the drive device 28. The near-infrared irradiation device 1 is controlled by controlling the tow conveyor 27 of No. 2 on the outgoing side.
0 is started toward the furnace body carry-out section C at the same time as the carriage 4 at the furnace body carry-in section A.

Moreover, the near-infrared irradiation device 10 is moved at a speed lower than the moving speed of the carriage 4 so as to follow the carriage 4.

In addition, in FIG. 1 and FIG. 3, the dolly 4 on which the article 8 is mounted and the near-infrared irradiation device 10 are shown separately for easy understanding.

As described above, in this embodiment, the coating film drying oven 1 is kept in a hot air atmosphere, and the article 8 to be coated is irradiated with near infrared rays to dry the coating layer on the article 8 to be coated. The temperature of the atmosphere in the furnace caused by the hot air is set to 100 ° C. or lower because it does not adversely affect the materials used when the coating film of the article to be coated 8 in which precision control equipment is mounted on the vehicle body is dried.

For the near infrared rays, for example, those having a wavelength peak of 1.2 to 1.5 μm are used. As a result of the experiment, the near-infrared ray having such a wavelength peak has good penetrability into the coating film, is absorbed by the interface between the coating material and the metal material of the article to be coated 8, and the temperature of the interface is rapidly raised, and the coating film is heated from the inside. It is known to have the property of heating.

Moreover, there is an effect that the surface temperature of the coating film can be prevented from being overheated by irradiating near infrared rays in a hot air atmosphere.

Therefore, by using the near infrared rays and hot air together, the coating film can be dried in a short time, and the material temperature of the article 8 to be coated, for example, the vehicle body is 80 ° C. or less, and the object temperature of precision control equipment is 70 ° C. The drying treatment can be performed at the following favorable drying temperature.

By the way, the near-infrared irradiation time becomes relatively longer as the tracking speed of the near-infrared irradiation device 10 becomes closer to the moving speed (constant) of the carriage 4. Now, regarding the relationship between the follow-up speed (moving speed) of the near-infrared irradiation device 10 and the near-infrared irradiation time, if the specifications of calculation are defined as shown in FIG. 4 and as follows, the following calculation formula is established.

Vw: Moving speed of the carriage (object to be coated) [unit:
m / min. ] Vl: Following (moving) speed of the near infrared ray irradiation device [unit: m
/ Min. ] Vl ′: Moving speed on the return side of the near infrared irradiation device [unit:
m / min. ] Lw: Length of object to be coated [unit: m] lo: Effective irradiation range of lamp [unit: m] L: Travel distance of truck [unit: m] l: Travel distance of near infrared irradiation device [unit: m] ] H: lamp irradiation heating time [unit: min. ] Lf: total length of the furnace effective part of the coating film drying furnace [unit: m] ht: tact interval for transferring the coated object [unit: min. ]

[0084]

[Equation 1]

[0085]

[Equation 2]

[0086]

(Equation 3)

From the above equation 1, when the near infrared ray irradiation device is fixed (Vl = 0),

[0088]

[Equation 4] If you put it

[0089]

(Equation 5) Becomes

These relationships are shown in FIG. 5 and Table 1.

[0091]

[Table 1]

Therefore, from these calculation formulas, graphs and tables, the following (moving) speed V of the near infrared ray irradiation device is shown.
It can be seen that the closer the 1 is to the moving speed Vw of the carriage (object to be coated), the longer the irradiation heating time H of the lamp becomes, and more rapid heating can be obtained.

However, since the lamp irradiation heating step must be completed within the length of the effective part of the coating film drying furnace,

[0094]

(Equation 6) Is constrained by.

Therefore, from Equation 5, Equation 2 and Equation 3,

[0096]

(Equation 7) therefore,

[0097]

[Equation 8] Must.

Regarding the transport tact of the article to be coated, the near-infrared irradiation device must be returned to the position of the furnace body loading section before the next article to be coated enters.

Therefore, the following equation 9 must be used.

[0100]

[Equation 9] ha: extra time on transportation

As described above, the object 8 to be coated on the carriage 4 is moved in the hot air atmosphere while moving to the furnace body unloading section C through the furnace body carry-in section A and the furnace body effective section B of the coating film drying furnace 1. Near-infrared rays are emitted from the lamp 15 of the near-infrared ray irradiation device 10 and dried by hot air and near-infrared rays.

Then, the dolly 4 approaches the furnace body unloading section C, and moves nearer to the dolly 4 near-infrared irradiation device 10.
The second contact portion 17 provided on the panel 11 of the
When the striker provided at is hit, a signal is sent from the second contact portion 17 to the control device 35.

Therefore, the control device 35 operates the power supply switch 24 to turn off the power supply 23 and turns off the lamp 15 of the near infrared ray irradiation device 10. At the same time, the forward / reverse switching unit 30 of the drive device 28 of the second tow conveyor 27 is switched to the reverse rotation side, the reversible motor 29 is driven to the reverse rotation side, and the second tow conveyor 2 is driven via the drive device 28.
Control 7 to the return side.

As a result, the near-infrared irradiation device 10 moves from the furnace body carry-out section C toward the furnace body carry-in section A, is sent to a fixed position in the furnace body carry-in section A, and is equipped with the next object to be coated. Wait for the entry.

On the other hand, the truck 4 that has reached the furnace body unloading section C
The dried product and the dried product are moved as they are by the first tow conveyor 9, pass through the furnace body unloading section C, and are sent to the next step.

In this embodiment, the panel 11 of the near-infrared irradiation device 10 is formed in a gate shape, and the plurality of lamps 15 are properly arranged on the inner surface of the panel 11, so that the object 8 to be coated mounted on the carriage 4 can be covered. Near-infrared rays can be emitted almost uniformly from the surroundings except the bottom surface.

Further, since the reflection plate 13 is attached to the panel 11 and the lamp 15 is attached to the reflection plate 13, it is possible to efficiently irradiate the article 8 with near infrared rays. Further, the lamp 15 is used until the near-infrared irradiation device 10 is moved to the return side until the next object 8 to be coated comes in.
Since is turned off, power consumption can be saved. Due to these synergistic effects, the coating film of the article to be coated 8 can be dried more satisfactorily and efficiently.

The hot air supplied to the coating film drying furnace 1 and used is sucked by the circulation fan 40 through the hot air circulation duct 39, purified by the filter 41 attached to the circulation fan 40, and then the hot air generator 37. Sent to and reused. Thereby, fuel consumption can be reduced and thermal efficiency can be improved.

When the type of the article 8 to be handled changes,
That is, for example, when the size of the article 8 to be coated, the difference in the wall thickness of the material, the thickness of the coating film, the paint, and the precision control equipment installed inside are different, the appropriate irradiation time of near infrared rays should be determined beforehand by experiments. Ask.

Then, the calculated irradiation time is input to the control device 35 and stored therein, and based on the irradiation time, a control signal is sent to the deceleration part 31 of the drive device 28 of the second tow conveyor 27 to make the furnace body loading part. The following speed of the near-infrared irradiation device 10 moved from A to the furnace body unloading section C is adjusted. As a result, it is possible to immediately cope with small-lot production of a wide variety of products.

In the present invention, the specific structure of each part is as follows.
The structure is not limited to the embodiment shown in the drawings, and may be any structure as long as it has a desired function.

[0112]

As described above, according to the first aspect of the present invention.
In the invention described, put the object to be coated into a coating film drying furnace, move the object to be coated at a predetermined speed from the furnace body carry-in section to the furnace body carry-out section, and the near-infrared irradiation device at the furnace body carry-in section. After the lamp is turned on and the near-infrared irradiation device is started simultaneously with the object to be coated, the near-infrared irradiation device is made to follow at a speed slower than the moving speed of the object to be dried and cured. Since the lamp of the near-infrared irradiation device is turned off and then sent to the furnace body loading section, for example, a large object to be coated, such as the body of a construction machine, and a precision control device pre-installed in the body, for example. The effect of being able to dry and cure the coating evenly and in a short time without adversely affecting the heat-sensitive precision control equipment, etc. due to the drying temperature, and further reducing fuel consumption In addition, there is an effect that the equipment can be downsized.

Further, in the invention according to claim 2 of the present invention,
The coating object is placed in a coating film drying oven under a hot air atmosphere, and the coating object is irradiated with near infrared rays under a hot air atmosphere,
By using the hot air and near infrared rays together, the hot air can prevent the coating film surface temperature from being overheated due to the near infrared rays, and thus the coating film can be dried. There are possible effects.

Further, in the invention according to claim 3 of the present invention,
Since the following speed of the near-infrared irradiation device with respect to the moving speed of the object to be coated is adjusted according to the type of the object to be coated, there is an effect that it is possible to cope with small-lot production of a wide variety of products.

In the invention according to claim 4 of the present invention,
A coating film drying oven equipped with a near-infrared irradiation device, a trolley mounted with an object to be coated and movably arranged in the coating film drying oven, and the trolley from a furnace loading section of the coating film drying furnace to a furnace body. A carriage moving means for moving at a predetermined speed toward the carry-out section, a near-infrared ray irradiation apparatus moving means for moving the near-infrared ray irradiation apparatus between the furnace body carry-in section and the furnace body carry-out section, and the furnace body carry-in section. The lamp of the near-infrared irradiation device is turned on and the near-infrared irradiation device is started at the same time as the dolly, and the near-infrared irradiation device is made to follow the dolly at a speed slower than the moving speed of the dolly, and the near-infrared light is emitted at the furnace body unloading part Since the irradiation device is equipped with a control device for turning off the irradiation device and for forwarding the near-infrared irradiation device to the furnace body loading section, there is an effect that the method for drying a coated object of the present invention can be carried out accurately.

In the invention according to claim 5 of the present invention,
The near-infrared irradiation device, a panel formed in a gate shape when viewed from the front, a reflector attached to the inside of both side plates of the panel and the ceiling plate, and a lamp attached to the inside of each reflector Since it is configured by including, there is an effect that the object to be coated can be dried more evenly around the periphery and efficiently.

Further, in the invention according to claim 6 of the present invention, the coating film drying furnace is equipped with a hot air supply device in addition to the near-infrared irradiation device, and the object to be coated is placed in a hot air atmosphere to Since I irradiate the coating with near infrared rays,
The combined use of the hot air and the near-infrared rays has the effect of preventing the surface temperature of the coating film from being overheated due to the irradiation of the near-infrared rays by the hot air and allowing the coating film to be dried in a shorter time and in a favorable manner.

According to the seventh aspect of the present invention, the hot air circulating device takes in the hot air used in the coating film drying furnace into the hot air supply device, regenerates it, and supplies it to the coating film drying furnace. Since the system is attached, there is an effect that fuel efficiency can be further reduced and efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view showing an example of an apparatus for carrying out a method for drying an article to be coated of the present invention.

2 is a vertical front view of FIG. 1. FIG.

3 is a cross-sectional plan view of FIG.

FIG. 4 is an explanatory diagram of specifications for obtaining a calculation formula of a near-infrared irradiation time from a moving speed of a coated object mounted on a carriage and a moving speed of a near-infrared irradiation device.

FIG. 5 is a graph showing a relationship between a moving speed of an object to be coated mounted on the carriage, a moving speed of a near infrared irradiation device, and a near infrared irradiation time.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Coating film drying furnace A ... Furnace body loading section B ... Furnace body effective section C ... Furnace body unloading section 4 ... Truck 8 ... Coating object 9 ... Truck to move first tow conveyor 10 ... Near infrared ray irradiation device 11 ... Panel of near-infrared irradiation device 13 ... Reflector 14 ... Receptacle 15 ... Lamp 16 ... First contact part 17 provided on panel 17 ... Second contact part 23 ... Lamp power supply 24 ... Power supply Switch 27 ... second tow conveyor which is a near-infrared irradiation device moving means 28 ... second tow conveyor drive device 29 ... same reversible motor 30 ... same forward / reverse switching part 31 ... same speed reduction part 35 ... control device 36 ... Hot air supply device 37 ... Hot air generator 38 ... Hot air supply duct 39 ... Hot air circulation duct 40 ... Circulation fan 41 ... Filter

Claims (7)

[Claims] 1. An object to be coated is placed in a coating film drying oven, and the object to be coated is moved at a predetermined speed from the furnace body carry-in section toward the furnace body carry-out section. After the lamp is turned on and the near-infrared irradiation device is started simultaneously with the object to be coated, the near-infrared irradiation device is made to follow at a speed slower than the moving speed of the object to be dried and cured. A method for drying an article to be coated, which comprises turning off the lamp of the near-infrared irradiation device and then sending it to the furnace body loading section. 2. The method for drying an article to be coated according to claim 1, wherein the article to be coated is placed in a coating film drying oven in a hot air atmosphere, and the article to be coated is irradiated with near infrared rays in an atmosphere of hot air. . 3. The method for drying an article to be coated according to claim 1, wherein the following speed of the near infrared ray irradiation device with respect to the moving speed of the article to be coated is adjusted according to the type of the article to be coated. 4. A coating film drying oven equipped with a near-infrared irradiation device, a dolly on which an object to be coated is mounted and which is movably arranged in the coating film drying furnace, and the dolly is a furnace body of the coating film drying furnace. A carriage moving means for moving at a predetermined speed from the carry-in part to the furnace body unloading part, a near-infrared ray irradiation device moving means for moving the near-infrared ray irradiation device back and forth between the furnace body carry-in part and the furnace body unloading part, and The lamp of the near-infrared irradiation device is turned on at the furnace body loading section, the near-infrared irradiation device is started simultaneously with the dolly, and the near-infrared irradiator is made to follow the dolly at a speed slower than the moving speed of the dolly. A drying device for an object to be coated, comprising: a control device for turning off the lamp of the near-infrared irradiation device at the carry-out part and forwarding the near-infrared irradiation device to the furnace loading part. 5. A panel in which the near-infrared irradiation device is formed in a gate shape when viewed from the front, reflectors attached inside both side plates of the panel and inside the ceiling plate, and inside each reflector. 5. The drying apparatus for the article to be coated according to claim 4, further comprising a mounted lamp. 6. The apparatus for drying an object to be coated according to claim 4, wherein the coating film drying furnace is equipped with a hot air supply device in addition to a near infrared ray irradiation device. 7. The hot air supply system is further provided with a hot air circulation system that takes in the used hot air in the coating film drying furnace, regenerates it, and supplies it to the coating film drying furnace.
A drying device for the coated article described.