JPH01210075A - Method and equipment for baking and drying coating material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method and apparatus for baking and drying paint, etc. A conductive heating plate arranged so as to surround the workpiece is heated under the action of an induction coil, and the entire workpiece is uniformly heated using the radiant heat of the heating plate, and the paint etc. is efficiently and The present invention relates to a method and device for baking and drying paint, etc., which enables accurate drying.

[Background of the Invention] For example, in the manufacturing process of an automobile body, an adhesive or a workpiece is applied to each part of the vehicle body as necessary, and a predetermined paint is applied to the vehicle body.

In this case, as a coating for the vehicle body, baking finish coating is widely used because it provides a strong and durable coating film. The baking finish coating heats the paint applied to the car body to speed up the volatilization of solvents such as thinner, and accelerates the reaction of the binder mixed in the paint, thereby curing the paint. At this time, the commonly adopted method for heating the paint applied to the car body is to place the car body in a drying oven and blow hot air onto the car body from a special drying device to heat and dry it. There is (Unexamined Japanese Patent Publication No. 5
5-119566).

However, in the drying method described above, since hot air is blown onto the vehicle body, local temperature differences tend to occur in the vehicle body. That is, the hot air is led out to the vehicle body from a plurality of air discharge ports provided substantially toward the vehicle body. Therefore, in order to uniformly heat the entire surface of the car body, it is necessary to arrange the air discharge ports as close to each other as possible, which makes the entire drying device quite expensive. It ends up. For this reason, in practice, the air discharge ports are spaced apart by a certain distance, and the amount of hot air blown onto the vehicle body differs depending on the area. as a result,
It has been pointed out that local temperature differences occur in the vehicle body, making it difficult to dry the paint uniformly over the entire body.

Moreover, due to the structure of the car body, there are parts that differ in rigidity etc.
The plate thickness of each part is substantially different. Therefore, if you want to dry the paint applied to the car body uniformly, hot air with a higher temperature than other parts will be applied to the thicker parts of the car body, depending on the thickness of each part of the car body. need to be supplied. However, as a result, the hot air discharged from each air outlet must be controlled to a predetermined temperature in advance, which results in complicated temperature control of the hot air, resulting in an increase in the manufacturing cost of the entire drying device. exist.

[Object of the Invention] The present invention has been made to overcome the above-mentioned disadvantages, and includes a method in which a workpiece or a workpiece coated with paint or the like is surrounded by a conductive heating plate, and the workpiece is placed outside the heating plate. A high-frequency current is supplied to the installed induction coil to induce an eddy current in the heating plate to heat the heating plate, and the workpiece is further heated by radiant heat from the heating plate, thereby uniformly heating the entire workpiece. To provide a method and device for baking and drying paint, etc., which can efficiently dry the work, paint, etc. applied to the work, and obtain a work with excellent appearance.

[Means for Achieving the Object] In order to achieve the above object, the present invention applies a paint etc., then introduces a workpiece into a conductive heating plate, and then places the workpiece outside the heating plate. A current is supplied to the installed induction coil to induce an eddy current in the heating plate, thereby heating the heating plate itself, and further heating the workpiece with radiant heat emitted from the heating plate, thereby coating the workpiece with paint, etc. It is characterized by being baked and dried.

Furthermore, the present invention is characterized in that when a workpiece is heated via a heating plate that is heated under the action of an induction coil, a gas is sprayed onto the surface of the workpiece to which paint or the like is applied.

The present invention also provides an apparatus for drying paint applied to a workpiece, which comprises a conductive heating plate having a space for introducing the workpiece and an induction coil provided outside the heating plate. At the same time, the induction coil and the heating plate are placed apart from each other by a predetermined distance, and the heating plate is inductively heated by energizing the induction coil, and the paint etc. on the workpiece is heated by the heat radiated from the heating plate. It is characterized by being configured to dry.

Further, the present invention is characterized in that the distance between the induction coil and the heating plate is substantially equal at any location.

Further, the present invention is characterized in that, when heating the workpiece, a gas supply means is provided for spraying gas onto the surface of the workpiece coated with paint or the like.

Furthermore, the present invention is characterized in that the interval between the induction coils corresponding to the thicker part of the coated surface of the workpiece is selected to be smaller than the interval between the induction coils corresponding to the thinner coated part. shall be.

[Embodiments] Next, preferred embodiments of the method and apparatus for baking and drying paint etc. according to the present invention will be described in detail with reference to the accompanying drawings.

In FIGS. 1 and 2, reference numeral 10 indicates a drying device for carrying out the method of baking and drying paint etc. according to the present invention. In this case, the drying device 10 bakes and dries the paint applied to the automobile body 14 that is conveyed via the conveying means 12.

The drying device 10 includes an induction coil 16 disposed outside the vehicle body 14, and a bent heating plate that is located between the induction coil 16 and the vehicle body 14 and defines an internal space so as to surround the vehicle body 14. 18.

The induction coil 16 is bent to surround the outside of the heating plate 18, folded back on both sides of the lower part of the vehicle body 14, and provided in parallel with the vehicle body 140 at a predetermined distance in the longitudinal direction. In this case, the induction coil 1
6 may be further folded back at a portion corresponding to the lower side of the vehicle body 14, and the spacing on the lower portion side may be selected to be narrower than the spacing on the other portions (see the two-dot chain line in FIG. 1). Also, one end of conducting wires 20a, 20b is connected to both ends of the induction coil 16, respectively, and the other end of the conducting wires 20a, 20b is connected to a power source 22.
is connected to.

On the other hand, the heating plate 18 is made of a conductive material and has a thickness of 2
It is formed from a steel plate of 111111 to 3 mm. The heating plate 18 is bent to have the same shape as the induction coil 16, and the heating plate 18 has an upper part 24, side parts 26a, 2
6b and the rain portions 28a, 28b are spaced apart from their respective corresponding portions of the induction coil 16 by an equal distance l (see FIG. 2). Further, a plurality of tube bodies 30a130b are attached to both side portions 26a, 26b of the heating plate 18, respectively, and the respective tube bodies 3Qa, 3Qb are connected to an air supply source (not shown), and are connected to the heating plate 1B. A plurality of exhaust ducts 32 are provided in the upper portion 24 at predetermined intervals.

In this embodiment, a plurality of pipe bodies 30a, 30b connected to an air supply source (not shown) and the exhaust duct 32 are fixed to the heating plate 18, but for example, one open end side of the heating plate 18 is fixed to the heating plate 18. It is also possible to introduce air into the heating plate 18 from the heating plate 18, or to supply air to the vehicle body 14 from the open lower side of the heating plate 18.

The drying device according to this embodiment is basically constructed as described above, and its operation and effects will be explained next.

First, the painted vehicle body 14 is transported by the transport means 12 to the inside of the heating plate 18 that constitutes the drying device 10 . Therefore, the power source 22 is driven to supply high frequency current to the induction coil 16 via the conductive wires 20a and 20b. Therefore, the high frequency current induces an eddy current in the conductive heating plate 18 positioned close to the induction coil 16, and the heating plate 18 itself is heated by this eddy current.

When the heating plate 18 is heated by the eddy current, as shown in FIG. 2, radiant heat is generated from the heating plate 18, and the air inside the heating plate 18 is heated to a predetermined temperature. It turns out. Therefore, the vehicle body 14 surrounded by the heating plate 18 is uniformly heated over its entire surface via the heated air, and the paint applied to the vehicle body 14 is dried.

At that time, a plurality of tube bodies a are operated under the action of an air supply source (not shown).
Air is supplied to the vehicle body 14 via oa and aob.

In this way, the air blown onto the vehicle body 14 flows in a laminar flow along the painted surface of the vehicle body 14 and is exhausted to the outside via the exhaust duct 32 located above the vehicle body 14. Thereby, the volatilization of the solvent from the painted surface of the vehicle body 14 can be further promoted, and the solvent can be prevented from remaining in the paint, thereby making it possible to obtain a smooth painted surface.

In this case, according to this embodiment, the vehicle body 14 can be
The paint can be dried efficiently and accurately by uniformly heating the entire painted surface of the paint.

That is, in the drying device 10, a heating plate 18 is arranged to surround the vehicle body 14, and an induction coil 16 is provided outside the heating plate 18 at a predetermined distance from the heating plate 18. . Therefore, when a high frequency current is supplied to the induction coil 16, the conductive heating plate 18 itself is heated by the induced current, and the air inside the heating plate 18 is heated at a constant rate throughout the entire area due to the radiant heat from the heating plate 18. The temperature is reached. Therefore, the entire vehicle body 14 surrounded by the heating plate 18 is heated to a uniform temperature, and unlike a conventional mechanism that blows hot air onto the vehicle body 14, local temperature differences occur in the vehicle body 14. Never. As a result, the paint applied to the vehicle body 14 can be kept in the same dry state throughout, making it possible to obtain a painted surface with excellent appearance.

Furthermore, even if the lower part of the car body 14 is thicker than other parts, the entire car body 14 can be heated to a uniform temperature through the drying device 10. I can do it. That is, in the induction coil 16, as shown by the two-dot chain line in FIG. 1, the distance between the portions corresponding to the lower side of the vehicle body 14 is narrower than the distances between the other portions. Therefore, if a high frequency current is supplied to the induction coil 16 under the driving action of the power source 22, the lower end sides of both side portions 26a 126b and both lower portions 28a of the heating plate 18 corresponding to the narrow interval portions of the induction coil 16, 28b becomes hotter than other parts. As a result, the temperature of the air near the lower side of the vehicle body 14 becomes higher than the temperature of the air in other parts of the vehicle body 14.
In particular, the lower side where the plate thickness is larger and the other parts are heated to the same temperature, making it possible to uniformly dry the entire painted surface of the vehicle body 14.

In addition, the heating temperature of the vehicle body 14 can be easily controlled by simply controlling the magnitude of the high-frequency current supplied to the induction coil 16, and the drying device 10 can perform drying operations well even for vehicle bodies of different models. One of the benefits is that it can be carried out in a number of ways.

In this embodiment, the drying operation of the paint applied to the car body 14 has been described, but the drying device 10 can be used, for example, to dry a workpiece, adhesive, etc. applied to the car body 14. This is easily understood.

Next, a drying apparatus according to another embodiment of the present invention is shown in FIG. In addition, the same reference numerals are attached|subjected to the same component as the drying apparatus 10 based on 1st embodiment, and the detailed description is abbreviate|omitted.

In this case, the drying apparatus 10a according to the second embodiment includes a plurality of induction coils, for example, three induction coils 16a to 16c. Connected to 22C.

In this way, in the drying apparatus 10a, substantially three induction coils 16a to 16c are connected to the power supplies 22a to 22, respectively.
Current is supplied individually through C. Therefore, in particular,
An advantage is obtained that a relatively large workpiece such as the car body 14 can be heated more efficiently. Although three induction coils 16a to 16c are used in the drying apparatus 10a, it is of course possible to increase or decrease the number of induction coils as necessary.

[Effects of the Invention] As described above, according to the present invention, when drying the workpiece, paint, etc. applied to the workpiece, the workpiece is surrounded by a heating plate formed of a conductive material, and this heating A high frequency current is supplied to an induction coil disposed outside the plate to heat the heating plate, thereby heating the workpiece through radiant heat from the heating plate. In this manner, by heating the heating plate itself surrounding the workpiece, the entire workpiece can be uniformly heated through the radiant heat from the heating plate. Therefore, the paint applied to the workpiece is dried under the same conditions over the entire workpiece, making it possible to obtain a painted surface with excellent appearance. Moreover, by spraying the gas onto the workpiece, it is possible to obtain the effect that, for example, the solvent that volatilizes from the painted surface of the workpiece can be prevented from remaining in the paint.

Further, when the thickness of the workpiece itself differs in parts, the interval between the induction coils corresponding to the thicker part is selected to be smaller than the interval in other parts. Therefore, where the induction coils are densely arranged, a large amount of conductive heating is achieved, and the temperature of the air corresponding to the thicker part of the workpiece becomes higher than the temperature of the air in other parts. This has the advantage that it is possible to carry out effective drying work even for works having partially different thicknesses. Also,
Even when the workpieces have different shapes, it is possible to dry the workpieces using the drying device, and the practical effect of providing an extremely versatile drying device is also realized.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments.
Of course, various improvements and changes in design are possible without departing from the gist of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of an apparatus for carrying out the baking drying method for paints, etc. according to the present invention, FIG. 2 is a front view showing an explanation of the operation of the drying apparatus shown in FIG. 1, and FIG. FIG. 1 is a schematic perspective view of a drying device according to an embodiment.

Claims (6)

[Claims] (1) After applying paint, etc., the workpiece is introduced into a conductive heating plate, and then a current is supplied to an induction coil arranged outside the heating plate to induce an eddy current in the heating plate. A method for baking and drying paint, etc., characterized in that the heating plate itself is heated, and the workpiece is further heated by radiant heat emitted from the heating plate, thereby baking and drying the paint, etc. applied to the workpiece. (2) In the method according to claim 1, when the workpiece is heated via a heating plate heated under the action of an induction coil, a gas is sprayed onto the surface of the workpiece to which the paint or the like is applied. baking drying method. (3) A device for drying paint etc. applied to a workpiece, which includes an electrically conductive heating plate having a space for introducing the workpiece, and an induction coil provided outside the heating plate. , the induction coil and the heating plate are arranged with a predetermined distance between them, the induction coil is energized to inductively heat the heating plate, and the heat radiated from the heating plate dries the paint etc. on the workpiece. A baking drying device for paint, etc., characterized in that it is configured as follows. (4) An apparatus for baking and drying paint, etc. according to claim 3, characterized in that the distance between the induction coil and the heating plate is substantially equal at any location. (5) The apparatus according to claim 3, further comprising a gas supply means for spraying gas onto the surface of the workpiece coated with paint or the like when heating the workpiece. (6) In the apparatus according to claim 5, an interval between the induction coils corresponding to a portion of the workpiece where the thickness of the coating surface is large is selected to be smaller than an interval between the induction coils corresponding to a portion of the coating surface where the thickness is small. 1. A baking drying device for paint, etc., characterized in that it is configured with: