JPH09145248A - Drying equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the heat of drying equipment from leaking and raising an ambient temperature, to thereby prevent deterioration of an environment of work and also to make the drying equipment small in size. SOLUTION: A predrying oven 4 and a baking drying over 5 are connected and made divisible by a partition plate 11. An opening 6 for carrying in a workpiece is made in the bottom of the end part of the predrying oven 4 and an opening 7 for carrying out the workpiece is made in the bottom of the end part of the baking drying oven 5. A workpiece carrier brought into the predrying oven 4 by a carrying-in-side lifter 29 is brought along an in-oven rail 3 and the workpiece carrier arriving at the end part of the baking drying oven 5 is brought out from this oven by a carrying-out-side lifter 37. A hot air circulating device 53 is provided in the predrying oven 4 and the workpiece is preheated by hot air. A hot air circulating device 60 and a far-infrared ray generating device 56 are provided in the baking drying oven 5 and an oven temperature is raised by the hot air circulating device 60 at the time of the start of operation, while the oven temperature is kept uniform by the far- infrared ray generating device 56 at the time of a steady-state operation.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to a drying apparatus.
In particular, the present invention relates to a drying apparatus for drying an object to be processed after performing a surface treatment such as electrodeposition coating, plating, and general coating.

[0002]

[Prior art]

(Explanation of electrodeposition coating line) In the electrodeposition coating line,
Racks for transporting an object to be processed (hereinafter, referred to as a work) are arranged at appropriate intervals, and a plurality of racks circulate along a line. At the loading position of the electrodeposition coating line, a plurality of works are loaded on each rack, for example, so as to be hooked, and the work loaded on the rack is transported along the line. First, in the degreasing process,
Oils and fats and oil stains adhering to the surface are removed by the dilute solution of sodium bichromate. Next, the work is washed in a water washing process (in some cases, ultrasonic cleaning is performed, and in the final water washing process, pure water cleaning is performed). After the moisture is removed, the work is cleared or gold is applied while voltage is applied. The surface is electrodeposited with a coating material in which a resin of a type suitable for the purpose, such as bronze, is dissolved. Next, the work is cleaned by a pure water shower.

[0003] The wet workpiece after the electrodeposition coating is sent to a drying step. In the drying step, the water and solvent of the work are removed, and the coating film is baked on the work.

The work on which the paint is baked in the drying step is cooled to near room temperature by natural heat radiation in the cooling zone, and is taken out of the rack at the unload position.

(Conventional Drying Apparatus) FIG. 20 shows a conventional drying apparatus 101 installed in a drying step of an electrodeposition coating line.
It is a schematic sectional drawing which shows the structure of. Conventional drying device 101
In this case, at both ends of the drying furnace main body 102 installed horizontally, an inclined work carrying path 103 and a work carrying path 10 are provided.
4 were connected. Also, sprockets 105 and 10
The work carrying path 103, the drying furnace main body 102, and the work carrying path 10
The chain 107 is stretched over the entire length of the internal space of No. 4. Further, a hot air circulation fan 108 is provided on the bottom surface of the drying furnace main body 102, and hot air heated by a heater 109 is blown into the inside of the drying furnace main body 102 to maintain a high temperature atmosphere.

[0006] At the entrance of the work loading path 103,
When the rack 110 holding the work (not shown) is hooked on a hook (not shown) provided on the chain 107, the rack 110 is conveyed through the drying device 101 by the chain 107. The work held in the rack 110 is pre-dried when the work is conveyed through the work carry-in path 103 to remove adhering moisture, is baked and dried in the drying furnace main body 102, and then is conveyed through the work carry-out path 104. While being cooled. Then, the rack 11 holding the work
Reference numeral 0 denotes an outlet of the work carrying path 104, which is detached from the hook of the chain 107.

[0007]

[Problems to be solved by the invention]

(The problem of heat) However, in the conventional drying apparatus 101, the work carrying path 103 and the work carrying path 104 which are inclined at both ends of the drying furnace main body 102 are provided, and the work carrying path 103 and the work carrying path 104 are provided. Is open to the outside, the hot air in the drying furnace main body 102 flows to the outside through the work carry-in path 103 and the work carry-out path 104, and when the drying apparatus 101 is in operation, the ambient temperature (room temperature) ) Was very high.

For this reason, in a factory or a booth in which the conventional drying apparatus 101 is installed, there is a problem that the room temperature becomes extremely high and the operation in a high-temperature environment is forced, thereby deteriorating the operation environment. Further, since the heat leaked from the drying furnace main body 102 was large, the energy loss of the drying device 101 was large, and thus the energy consumption was large.

(Problem of Product Quality) Conventional Drying Apparatus 101
, The hot air drying method is used, and since the air flows in and out of the drying device 101 inside and outside, dust is easily generated inside the drying device 101, and the dust adheres to the work and the product quality And the defective rate was high.

(Problem of occupied area) Conventional drying apparatus 101
In this embodiment, the inclined work carry-in path 103 and the work carry-out path 104 are provided on both sides of the drying furnace main body 102.
1 was getting longer. For this reason, it occupies a large installation area, and it cannot be installed when the installation area is limited. Also, the cost of the installation space was high.

In the conventional drying device 101,
Since the racks 110 are suspended and conveyed at regular intervals on the chain 107, when the racks 110 are conveyed in an inclined direction as shown in FIG. 21A, the racks 110 are horizontally conveyed as shown in FIG. 21B. Racks 110 approach each other as compared to the state in which Therefore, the rack 1 is
In order to prevent collisions between the racks 10, the racks 11 are transported in the inclined direction depending on the state of the racks 11.
The distance d between the 0 suspension positions is regulated.

More specifically, the distance between the hanging positions of the rack 110 is d, and the work carrying path 103 and the work carrying path 1
04 is θ, the width of the rack 110 is w, and even when the racks 110 approach each other, the rack 11
It is assumed that there is a gap of α% of the width w of the rack 110 between zero.
In this case, as can be seen from FIG. 21A, the interval d between the hanging positions of the rack 110 is expressed as d = (1 + 0.01α) w / cos θ. Now, if α% = 10% and θ = 45 °, d = 1.56w is obtained from the equation. Therefore, when the gap α% between the racks 110 is set to 10% in the inclined portion, the gap β% between the racks 110 is as large as 56% in the drying furnace main body 102 which is horizontally conveyed.

As described above, in the drying furnace main body 102, the rack 1
Since a large gap is formed between the racks 10 and the transport density of the racks 110 cannot be increased, the total length L2 of the drying furnace main body 102 becomes longer even when the same number of racks 110 are dried at one time, and thus the total length L1 of the drying device is reduced. I couldn't.

(Problem of uneven baking temperature) Further, since the hot air in the drying furnace main body 102 leaks out as described above, the internal temperature in the drying furnace main body 102 is not uniform. FIG.
FIG. 4 is a diagram showing a change in the internal temperature inside the drying apparatus, where the maximum temperature Tmax is at the center of the drying furnace main body 102 from which hot air is blown out, but since the hot air leaks from both ends, the drying furnace In the main body 102, the internal temperature greatly changes along the work transfer direction. As a result, there is a problem that the baking temperature of the work is not uniform.

The present invention has been made in view of the above-mentioned drawbacks of the conventional example, and has as its object to provide a drying apparatus which is compact and occupies a small area.

Another object of the present invention is to reduce a rise in ambient temperature due to heat leaking from a drying device and improve the working environment.

Still another object of the present invention is to make the internal temperature in the drying device uniform.

[0018]

DISCLOSURE OF THE INVENTION In the drying device according to claim 1, the drying device body is provided with at least one of a work carrying-in port and a work carrying-out port, and the work carrying-in port or the work carrying-out port is opened on the bottom surface of the drying device body. It is characterized by that.

Here, the work carry-in port is an opening for carrying a work from the outside (for example, a room space) into the drying device, and the work carry-out port is carried out from the drying device to the outside (for example, the room space). And does not include an opening for connecting the drying device to another drying device. Therefore, when the drying device is provided with both the work carrying-in port and the work carrying-out port, it is necessary to open both at the bottom surface of the drying device body. However, for example, when connecting and using different types of drying devices, each drying device has only one of the work entrance and the work exit. It suffices if only one of the work outlets is opened.

In this drying apparatus, since the work entrance and the work exit, which have been heat leaks, are opened at the bottom surface of the drying apparatus frame, the hot air accumulates above the drying apparatus frame. It is less likely to leak from the work entrance and the work exit. Therefore, in the drying device of the first aspect, the effect of confining heat is high, and high-temperature hot air is unlikely to leak out of the device.

Therefore, even during the operation of the drying device, the ambient temperature, that is, the room temperature does not abnormally rise due to the heat leaking from the drying device. For this reason, the surrounding work environment can be kept favorable. In particular, even when the drying device is compact and installed in a small installation area, it can be said that the meaning of maintaining a favorable working environment is significant.

Furthermore, since the hot air of the drying device hardly leaks to the outside, the energy consumption of the drying device is reduced and the effect of energy saving is high. Further, since the hot air of the drying device does not leak to the outside and the effect of confining the hot air is high, the internal temperature can be made uniform as compared with the conventional drying device.

According to a second aspect of the present invention, in the drying apparatus according to the first aspect, the work carrier holding the work is moved up and down in a substantially vertical direction, and the work carrier is conveyed from the work carry-in port or the work carry-out port. It is characterized in that it is provided with a work carry-in device or a work carry-out device for carrying in and out.

In the drying device according to the second aspect, the work carry-in port and the work carry-out port are opened on the bottom surface of the drying device body, and the work carrier is substantially vertical at the work carry-in port and the work carry-out port. Since it is loaded and unloaded into and from, unlike the conventional drying device, there is no inclined part such as the work loading path and the work loading path at both ends, which improves the space utilization efficiency in the height direction of the installation space. The overall length can be shortened, the size can be reduced, and the occupied area can be reduced as compared with the conventional one. Therefore, the drying device can be installed in a narrow place, which is particularly convenient when the installation area is limited. Furthermore, since the occupied area is reduced, the cost of the installation space can be reduced. Further, the manufacturing cost of the drying device itself can be reduced by making the device compact.

According to a third aspect of the present invention, in the drying apparatus according to the first aspect, the work carrier is moved in the horizontal direction by the carrier means capable of varying the interval between the work carriers holding the work. It is characterized by having done.

According to the third aspect of the present invention, the distance between the work transfer bodies can be varied so that the distance between the work transfer bodies can be minimized according to the stage of the drying process. Therefore, the transfer density of the work transfer body can be increased in accordance with the drying stage, and the drying device can be made more compact. Therefore, the area occupied by the drying device can be reduced, and the drying device can be installed in a narrow place.

According to an embodiment of a fourth aspect, in the drying apparatus according to the first aspect, there is provided a device for blowing air to the work by an air nozzle installed near the work carry-in port to remove moisture. It is characterized by that.

In the drying device of this embodiment, the excess water droplets and water adhering to the work can be dried by roughly blowing air and then the work can be dried. Can be lightened. Therefore, it is possible to further reduce the size of the drying device and save energy.

A fifth aspect of the present invention is characterized in that the drying apparatus according to the first aspect includes a convection heating means and a radiation heating means. In particular, the radiation heating means is preferably a plurality of far-infrared ray generating devices as in the embodiment of the sixth aspect.

In this embodiment, at the start of the operation of the drying apparatus, the temperature in the furnace can be quickly raised to the target temperature in a short time by circulation of hot air. further,
After the in-furnace temperature approaches or reaches the target temperature, it is possible to perform baking drying with energy saving by heating with radiation such as far-infrared rays, and at the same time, it is possible to reduce an increase in ambient temperature.

An embodiment according to claim 7 is characterized in that, in the drying apparatus according to claim 6, the far-infrared ray generating device is divided into a plurality of sections, and the temperature is controlled for each section.

As in this embodiment, by controlling the temperature of the far-infrared ray generator for each section for each section, the temperature distribution inside the drying apparatus can be made uniform.

According to an eighth aspect of the present invention, in the drying apparatus according to the first aspect, the hot air circulating duct opened to the drying device body and the hot air circulating duct connecting the hot air blowing port and the hot air circulating port are discharged. It is characterized in that it is provided with a heater and a blower fan for heating the heated air and discharging it from the hot air outlet to the inside of the dryer body.

According to the embodiment of the present invention, since the air in the drying device can be heated while being circulated through the hot air circulation duct, the heating device can be heated even if convection heating means is used. Does not escape to the outside of the apparatus, and the temperature inside the drying apparatus can be efficiently increased. In addition, since the heat of the drying device does not escape, the surrounding temperature does not increase and the working environment does not deteriorate.

The embodiment described in claim 9 is characterized in that, in the drying device according to claim 1, a predrying oven and a baking oven are connected in series, and the communication port can be opened and closed by a partition plate. There is.

In an embodiment according to the ninth aspect, a partition plate is provided so as to connect the preliminary drying furnace and the baking drying furnace, and a partition is provided when the workpiece is moved from the preliminary drying furnace to the baking drying furnace. The plate is opened, but the partition is closed during drying.

Therefore, after the work is preheated in the preliminary drying furnace, baking drying can be performed in the baking drying furnace, and the energy saving of the drying apparatus can be achieved. In addition, it is prevented that the hot air is mixed between the pre-drying oven and the baking drying oven to cause the internal temperature to change slowly between the pre-drying oven and the baking drying oven. The change can be sharp.

[0038]

BEST MODE FOR CARRYING OUT THE INVENTION

(One Embodiment of the Present Invention) FIG. 1 is a schematic cross-sectional view showing a drying device 1 according to one embodiment of the present invention, and FIG. 2 suspends a work carrier 2 holding a work (not shown) from a rail 3 in a furnace. It is a schematic sectional drawing of the drying device 1 which shows the lowered state. The drying apparatus 1 includes a separate pre-drying furnace 4 and a baking drying furnace 5. The communication port of the pre-drying furnace 4 is connected to the communication port of the baking drying furnace 5, and the pre-drying is performed by fasteners such as bolts and nuts. The furnace 4 and the baking / drying furnace 5 are connected and integrated. In the drying apparatus 1 including the predrying furnace 4 and the baking drying furnace 5, a work entrance 6 is opened at the bottom of the skeleton of the predrying furnace 4, and the skeleton of the baking drying furnace 5 is opened. A work outlet 7 is opened on the bottom surface. Accordingly, the work carry-in port 6 and the work carry-out port 7 are open vertically downward. The preliminary drying furnace 4 and the baking drying furnace 5 may be configured as an integrated body from the beginning.

The predrying furnace 4 has a relatively low temperature (for example, 6
By heating the work at 0 to 100 ° C., moisture, a solvent and the like attached to the work are blown off. Further, by heating the work at a relatively low temperature before the baking step, the peeling of the coating film is prevented, and the temperature in the baking / drying furnace 5 is prevented from being lowered by the work. Further, the baking drying furnace 5 heats the coating film formed on the surface of the work to a work by heating at a relatively high temperature (for example, a temperature of a maximum of 220 ° C., typically a temperature of about 100 to 200 ° C.). It is to be baked.

The drying apparatus 1 comprising the preliminary drying furnace 4 and the baking drying furnace 5 will be described in detail below (however, in the plating step, either type of drying is performed so that only the preliminary drying furnace is used). It can be configured as a furnace). The drying device frame 8 is composed of a frame of the preliminary drying furnace 4 and a frame of the baking / drying furnace 5, and details thereof are not shown.
The frame is formed by assembling a steel frame, and the wall surface is formed by a heat insulating panel so that heat does not escape easily. FIG.
As shown in the figure, a cylindrical skirt portion 9 is suspended from the bottom surface at one end, and a work carrying entrance 6 is opened at the lower surface of the skirt portion 9. Further, a cylindrical skirt portion 10 hangs down from the bottom surface of the other end of the drying device frame 8, and a work outlet 7 is opened on the lower surface of the skirt portion 10. The predrying furnace 4 and the baking drying furnace 5 are connected to each other through a communication port. The inside of the predrying furnace 4 and the inside of the baking drying furnace 5 can be separated from each other by a partition plate 11. . For example, in the embodiment of FIG.
The partition plate drive device (not shown) allows the partition plate 11 to enter and exit the drying device 1 from the bottom surface of the drying device frame 8.

(Explanation of Furnace Transfer Mechanism) As shown in FIG. 2, a plurality of work transfer bodies 2 for transferring a work
In the pre-drying furnace 4 and the baking-drying furnace 5, it moves along the in-furnace rail 3. The in-furnace rail 3 is disposed horizontally from the end of the preliminary drying furnace 4 to the end of the baking / drying furnace 5 on the lower surface of the ceiling inside the drying device 1. Work carrier 2
Consists of a work transfer slider 12 slidably engaged with the furnace rail 3 and a work holding rack 13 suspended below the work transfer slider 12. 3 are sequentially sent.

FIGS. 5A and 5B are a side view and a partially cutaway front view showing the structure of the furnace rail 3 and the work transfer slider 12, respectively. The in-furnace rail 3 is formed by attaching a resin portion 16 for reducing wear over the entire length of the upper surface of a metal beam 15. As a material of the resin portion 16, a plastic material having a small friction coefficient and excellent wear resistance is preferable. For example, a fluorine-based resin such as polypropylene, high-density polyethylene, and polytetrafluoroethylene (PTFE) can be used. Work transfer slider 12
Puts the sliding block 17 on the upper surface of the furnace rail 3 and engages with the furnace rail 3 so as to sandwich the furnace rail 3 between both side plates 18a and 18b. A hanger 19 for hooking is provided.

FIGS. 6A and 6B show the work transfer slider 1.
2A and 2B are a side view and a front view showing a feeding device 14 for pushing and feeding the feed roller 2; The feed device 14 has support bars 21 at appropriate intervals on the lower surface of a feed bar 20 movably supported in the horizontal direction.
, And a feed claw 22 is rotatably attached to the lower end of each support rod 21. The tip of the feed claw 22 rotates upward from the posture shown in FIGS. 6A and 6B, but its rotation angle is regulated so as not to move downward from the posture. A rack gear 23 is provided on the upper surface of the feed bar 20, and a pinion gear 24 meshes with the rack gear 23. A drive gear 26 is attached to an output shaft of a drive device 25 including a motor and a speed reducer, and a chain 27 is wound between the rack gear 23 and the drive gear 26. Thus, when the driving device 25 is driven, the feed bar 20 is moved forward in the horizontal direction, and by reversing the rotation direction of the drive gear 26, the feed bar 20 can be moved backward. 22 moves forward and backward at the same time.

FIGS. 7A to 7D are views for explaining the operation of feeding each work transfer slider 12 along the in-furnace rail 3 by the feed device 14. FIG. When the feed bar 20 is slid backward and the feed claw 22 is retracted from the front to the initial position (the rear end of the moving range of the feed claw 22), the feed claw 22 rotates upward at the position of the work transfer slider 12. As a result, the work transport slider 12 slides over the upper surface of the work transport slider 12 and moves backward (FIG. 7A). When the feed claw 22 returns to the initial position in this way, the feed claw 22 stops (FIG. 7B). The distance S generated between the feed claw 22 and the work transport slider 12 when the feed claw 22 returns to the initial position differs depending on the distance between the work transport sliders 12. Thereafter, when the feed bar 20 slides forward to advance the feed claw 22, the front end surface of the feed claw 22 hits the work transport slider 12 and is caught (FIG. 7).
(C)), as the feed bar 20 advances, the feed claws 22 push the work transfer slider 12 forward. The work transfer slider 12 is at a predetermined position (the front end of the moving range of the feed claw 22)
, The feed bar 20 stops (FIG. 7D). When the work transfer slider 12 has been fed to the predetermined position, the feed bar 20 retreats again. By repeating such an operation, the feeder 14 sequentially feeds the work transport slider 12 holding the rack 13 forward.

Here, by changing the distance between the feed claws 22 of the feed device 14, the interval between the work transfer sliders 12 can be freely changed even during the transfer. According to this, the interval between the work carriers 2 can be freely changed at an arbitrary position. Here, as shown in FIG. 2, the interval between the workpiece carriers 2 in the baking / drying furnace 5 is made smaller than the interval between the workpiece carriers 2 in the preliminary drying oven 4. Furthermore, since the distance between the work carriers 2 can be shortened, the overall length of the drying device 1 can be shortened.

(Description of Work Loading Mechanism) Work Loading Port 6
From the lower space to the upper space (inside the predrying furnace 4), a lifting and lowering loading device 28 is provided. The lifting and lowering loading device 28 vertically lifts and lowers the loading side lifter 29 to transport the work carrier 2 into the preliminary drying furnace 4. The loading side lifter 29 has the same form as the furnace rail 3. It has a short rail shape. The carry-in side lifter 29 moves up and down between a receiving position below the work carry-in entrance 6 and a position above the work carry-in entrance 6 and in line with the furnace rail 3.

A relay rail 30 is provided at the same height as the receiving position of the work carrier 2, and a carry-in pusher 31 is provided near the relay rail 30.

Various mechanisms can be used as a mechanism for raising and lowering the lifter 29 in the lifting and lowering device 28. For example, the loading side lifter 29 may be supported vertically from below by a lifting mechanism installed on the floor, such as a table lifter, and may be moved vertically. Or,
The carry-in side lifter 29 may be suspended from the ceiling surface of the preliminary drying furnace 4 and the carry-in side lifter 29 may be raised and lowered from above. Further, a self-propelled type in which the lifting / lowering loading device 28 provided with the loading-side lifter 29 itself can be moved up and down. Or,
A lifting mechanism may be provided on the side surface of the preliminary drying furnace 4.

FIG. 3 illustrates an example in which a lifting mechanism for the carry-in side lifter 29 is provided vertically on the side surface of the preliminary drying furnace 4. In the lifting and lowering device 28, an arm 32 is provided so as to be vertically movable along the side surface of the preliminary drying furnace 4, and a loading side lifter 29 is supported at the tip of the arm 32. A chain 35 is hung between sprockets 33 and 34 disposed vertically on the side surface of the predrying furnace 4, and a base end of the arm 32 is fixed to the chain 35. Thus, either sprocket 32 or 3
By driving the chain 3 and running the chain 34, the carry-in side lifter 29 is moved up and down together with the arm 35. For example, the carry-in side lifter 29 is moved to the same height as the relay rail 30 or the furnace rail 3 by a limit switch. By detecting that the loader has become unloaded, the carry-in side lifter 29 is moved up and down between the relay rail 30 and the furnace rail 3.

(Explanation of the work unloading mechanism) In addition, from the space below the work outlet 7 to the space above (inside the baking / drying furnace 5).
, A lifting device 36 is provided. The elevating and unloading device 36 is configured to vertically lift and lower the unloading-side lifter 37 to unload the work carrier 2 from the baking / drying furnace 5, and the unloading-side lifter 37 has the same form as the furnace rail 3. , Short rail shape. The carry-out side lifter 37 is used to move the furnace rail 3 above the work carry-out port 7.
Is moved up and down between a position aligned in a straight line and a transfer position below the work outlet 7.

A relay rail 38 is provided at the same height as the transfer position of the work carrier 2, and an unloading pusher 39 is provided near the relay rail 38.
Various lifting mechanisms can be used as the lifting / lowering device 36, similarly to the lifting / lowering device 28. For example, a lifting mechanism installed on the floor surface such as a table lifter may be used to support the lifting-side lifter 37 from below and vertically move up and down. The lifting-side lifter 37 may be suspended from the ceiling of the baking / drying furnace 5. It is also possible to raise and lower the carry-out side lifter 37 from above. Alternatively, it may be a self-propelled type in which the lifting / lowering carrying-out device 36 provided with the carrying-out side lifter 37 moves up and down. Alternatively, a baking / drying furnace 5 may be provided with an elevating mechanism on the side surface (see FIG. 3).

(Transfer Order of Work Carrier) In practice, the work carrier 2 is continuously conveyed while maintaining a predetermined interval as shown in FIG. 2, but for convenience of explanation, FIG.
19 shows that only one work carrier 2 is sequentially fed. 14 to 19, a description will be given of how the work transfer body 2 is loaded from the work loading port 6 of the preliminary drying furnace 4 and unloaded from the work loading port 7 of the baking drying furnace 5.

When the surface treatment of the work is completed, the work carrier 2 holding the work is sent to the preliminary drying furnace 4 by a carry-in device (not shown). This carrying-in device also has a carrying-in rail-like body 40 having the same form as the carrying-in side lifter 29. That is, the carry-in rail 40 has the same form as the in-furnace rail 3 and has a short rail shape. The work carrier 2 holding the work on which the surface treatment has been completed is sent to the preliminary drying furnace 4 by the carry-in device while being suspended from the carry-in rail 40. The carrying-in rail-shaped body 40 stops at a position aligned with the relay rail 30. At this time, the carry-in side lifter 29 is waiting at the receiving position so as to be linear with the relay rail 30, so that the carry-in rail 40 and the relay rail 3
0 and the carry-in side lifter 29 are aligned in a straight line. Then
When the work carrier 2 is pushed in by the carry-in pusher 31, the work carrier 2 suspended from the carry-in rail 40 is moved to the carry-in side lifter 29 through the relay rail 30 (FIG. 14). . At this time, air is blasted toward the work from the air knife device 41 installed below the work entrance 6,
Moisture adhering to the work is roughly blown off by the air.

The carry-in side lifter 29 receiving the work carrier 2 rises to the same height as the in-furnace rail 3 while holding the work carrier 2 (FIG. 15). When the carry-in side lifter 29 stands still at the same height as the furnace rail 3, the feeder 14 operates, and the work carrier 2 suspended from the carry-in side lifter 29 is pushed by the feed claw 22 and moved into the furnace rail 3.
(FIG. 16). After this, the work carrier 2 is sequentially sent by the feeding device 14 and sent from the preliminary drying furnace 4 to the baking drying furnace 5 (FIG. 17).

When the work carrier 2 baked and dried with the coating film on the surface of the work through the preliminary drying furnace 4 and the baking drying furnace 5 reaches the end of the in-furnace rail 3, the work carrier 2 is moved by the feeding device 14. It is sent to the carry-out side lifter 37 of the lifting / lowering carry-out device 36 which has been waiting at the same height as the furnace rail 3 (FIG. 18). The unloading side lifter lifter 37 receiving the work carrier 2 moves down to the height of the relay rail 38 while holding the work carrier 2. On the other hand, the unloading rail 42 of the unloading device (not shown) stands by at a position in line with the relay rail 38. This carrying-out rail-like body 42 is also the same as the carrying-in rail-like body 40,
It has the same form as the furnace rail 3. When the unloading lifter 37 that suspends the work carrier 2 stops at a position aligned with the relay rail 38, the unloading pusher 39 operates. As a result, the work carrier 2 suspended from the carry-out side lifter 37 is pushed by the carry-out pusher 39, and is transferred to the carry-out rail 42 via the relay rail 38 (FIG. 19). The unloading rail 42 receiving the work carrier 2 carries the work carrier 2 to the next step.

Since the drying device according to the present invention has the above-described configuration, the size of the device can be reduced.
For example, the size of the baking / drying device can be reduced to about 1/2 of the conventional size, and the total length of the combined pre-drying furnace and baking / drying furnace can also be reduced to about 1/2 of the conventional size. Can be planned.

Further, if such a transfer mechanism is used, the transfer of the work transfer body between the steps before and after the drying apparatus can be automated, and the drying apparatus can be inlined.

(Drying Process of Coating Film) Next, the drying process of the coating film applied to the surface of the work will be described in detail. First, before the work enters the predrying furnace 4, moisture adhering to the work is roughly removed by an air knife device. Next, in the preliminary drying furnace 4, preheating is performed at a temperature of about 60 to 100 ° C. by hot air, and in the baking and drying furnace 5, a maximum of 220 ° C. (typically, 100 to 100 ° C.) is mainly caused by ambient temperature and far infrared rays. It is baked and dried uniformly at an arbitrary temperature of about 200 ° C.).

The air knife device 41 has a structure as shown in FIG.
Is connected by an air pipe 45, and the air pipe 45 is provided with an electromagnetic on-off valve 46. Further, a plurality of air nozzles 47 installed below the work carry-in port 6 and an outlet side of the air tank 44 are also connected to the air piping 48.
The air pipe 48 is provided with an electromagnetic on-off valve 49 and a flow control valve 50.

9 (a) and 9 (b) are time charts showing opening / closing operations of the electromagnetic opening / closing valves 46 and 49, respectively.
(C) is a diagram showing a change in the air pressure in the air tank 44. In the air knife device 41, while the work carrier 2 is not passing between the air nozzles 47, the electromagnetic opening / closing valve 49 on the air nozzle 47 side is closed and the compressor 43 is closed.
Side electromagnetic switching valve 46 is open. Therefore, during this period, air is sent from the compressor 43 into the air tank 44, and the air pressure in the air tank 44 gradually increases. When the air pressure in the air tank 44 reaches a constant value, the electromagnetic opening / closing valve 46 is closed and the air pressure in the air tank 44 is maintained at a constant value. Then, when the work carrier 2 passes between the air nozzles 47, the electromagnetic on-off valve 49 on the air nozzle 47 side is opened, and a large amount of air compressed and stored in the air tank 44 is vigorously discharged from the air nozzle 47. Blow off the moisture adhering to the. Note that the amount of air discharged from the air nozzle 47 can be adjusted by the flow control valve 50.

Thus, such an air knife device 41
According to the above, the air pressure of the compressor 43 is
Since it is amplified inside and is discharged from the air nozzle 47 at once, a relatively small compressor 43 can discharge a large amount of air from the air nozzle 47. Therefore, labor for blowing air to the work by manual work can be saved, labor can be saved, and the apparatus for blowing air can be made compact.

(Drying Process in Predrying Furnace) A heater (steam erofin heater) is provided on the bottom surface of the predrying furnace 4.
A hot air circulation device 53 including a fan 51 and a blower fan (sirocco fan) 52 is attached. Further, as shown in FIG.
The hot air outlet 54b and the hot air circulation port 54a opened at the bottom of the preliminary drying furnace 4 are connected by a hot air circulation duct 55 and a hot air circulation device 53.

Thus, the hot air circulating device 53 is the drying device 1
The air in the preliminary drying furnace 4 is sucked into the blower fan 52 through the hot air circulation port 54a and the hot air circulation duct 55, heated by the heater 51, and then heated as hot air. 52, it is forcibly blown out from the hot air outlet 54b into the preliminary drying furnace 4,
The inside of the preliminary drying furnace 4 is heated. As shown in FIG. 10, in a state where the partition plate 11 between the baking and drying furnace 5 is closed and the preheating of the work is performed, as shown in FIG. It is kept at a uniform temperature.

In such a predrying furnace 4, the hot air circulates in the predrying furnace 4 and does not blow out from the work loading port 6. Since hot air does not escape to the outside from the work carry-in port 6 which accumulates at the upper portion and is opened at the bottom of the preliminary drying furnace 4,
The effect of confining the hot air in the preliminary drying furnace 4 is very high.
Further, by forcibly circulating the hot air in the preliminary drying furnace, the thermal efficiency can be improved and the temperature distribution in the preliminary drying furnace can be made uniform. Furthermore, as a result of the higher thermal efficiency, the size of the hot air circulation device 53 can be reduced as compared with the case where the circulation system is not used.
Dust is less likely to be generated in the predrying furnace 4 and dust is less likely to adhere to the work, so that product quality can be improved.

(Drying Process in Baking Drying Furnace) The structure inside the baking drying furnace 5 is shown in FIGS. The inside of the baking / drying furnace 5 is divided into three zones Z1, Z2, and Z3. Each of the zones Z1, Z2, and Z3 has a temperature sensor 57 such as a thermocouple for detecting the furnace temperature.
A far-infrared ray generator 56 including a number of far-infrared radiation heaters 61 is provided. Infrared radiation heater 61
Are arranged so that far-infrared radiation can be emitted to the entire work in the furnace. The temperature in the furnace is detected by each temperature sensor 57 for each of the zones Z1, Z2, and Z3, and based on the temperature, the far-infrared rays are generated so that the temperatures of the zones Z1, Z2, and Z3 become the set furnace temperatures. The output of the devices 56 is individually controlled. The detection position of the temperature sensor 57 for controlling the far-infrared ray generating device 56 is preferably installed near the center of the upper part of the furnace and near the pass area of the workpiece.

FIG. 12 shows the circuit configuration of the far-infrared ray generator 56 in each of the zones Z1, Z2 and Z3. The plurality of far-infrared radiation heaters 61 are delta-connected (one resistance symbol shown in FIG.
Are connected in parallel.) Thyristor regulator 6
2 output terminal. The input terminal of the thyristor regulator 62 has a knife type breaker 63.
The three-phase AC power supply 64 is connected via the. The temperature sensor 57 is connected to a temperature controller 65 containing a microcomputer (CPU), and the temperature controller 65 is connected to a control terminal of the thyristor regulator 62. When the temperature sensor 57 detects the temperature of the zone, the temperature controller 65 calculates the firing angle of the thyristor regulator 62 based on the deviation between the detected temperature and the set furnace temperature. The thyristor regulator 62 controls the power of the far-infrared radiation heater 61 based on the firing angle calculated by the temperature controller 65 to generate heat. By adjusting the furnace temperature for each of the zones Z1, Z2, and Z3 in this manner, the inside of the baking / drying furnace 5 is maintained at a uniform furnace temperature.

As shown in FIG. 11 (b), a hot air outlet 66b is also opened at the bottom of the baking / drying furnace 5, and an electric heater (resistance wire) 58 and a blower are provided below the hot air outlet 66b. A hot air circulation device 60 including a fan (sirocco fan) 59 is attached. Further, a diffuser (rectifying plate) 69 is arranged over the entire surface, slightly above the bottom surface of the baking / drying furnace 5. A hot air circulation port 66a is opened in the upper part of the side wall of the baking drying furnace 5, and the hot air circulation port 66a and the hot air outlet 66b are connected by a hot air circulation duct 67 and a hot air circulation device 60. The hot air in the furnace sucked from the hot air circulating port 66a is sent to the hot air circulating device 60 through the hot air circulating duct 67, heated by the electric heater 58, and then blown out of the hot air blowing port 66b. The hot air blown out from 66b is spread over the entire furnace by the diffuser 69, and is blown uniformly into the baking / drying furnace 5. Another temperature sensor 68 including a thermocouple or the like is provided above the hot air outlet 66b, and hot air circulation is performed based on the temperature inside the furnace of the baking / drying furnace 5 and the temperature inside the furnace detected by the temperature sensor 68. The blowing temperature and the air volume of the device 60 are controlled. The position detected by the temperature sensor 68 is preferably a position near the center of the upper part of the furnace, which is not irradiated with far infrared rays.

In the baking / drying furnace 5, when the furnace temperature rises, the furnace temperature is raised only by the hot air circulation device 60. After the furnace temperature approaches or reaches the target temperature, the electric heater 58 is turned off and the far-infrared ray generator 56 is turned on. Alternatively, the far-infrared ray generating device 56 is turned on while the electric heater 58 is kept on even after the furnace temperature approaches or reaches the target temperature depending on the type of the work or the like. Irrespective of ON / OFF of the electric heater 58 in the furnace, the blower fan 59 continues to operate and keeps the furnace temperature uniform. After turning on the far-infrared ray generating device 56, the temperature of each zone Z1, Z2, Z3 in the furnace is detected by each temperature sensor 57, and the temperature of the entire furnace is 220 ° C. at maximum (typically 100 to 200 ° C.). The output of each far-infrared ray generator 56 is individually controlled for each of the zones Z1, Z2, and Z3 so as to be uniform at about (° C.). Thus, the workpiece is baked and dried by the ambient temperature and the far-infrared ray during the steady operation.

After the far-infrared ray generator 56 is turned on and the baking and drying steady-state operation is started, the air volume of the blower fan 59 may be reduced or the operation may be intermittently performed. Further, in the above embodiment, the temperature control area by the far-infrared ray generating device 56 in the baking / drying furnace 5 is divided into three zones, but this may be divided into two zones, or four or more zones. May be classified.

Here, the method of baking and drying only with the hot air heated by the electric heater 58 has the advantages that the starting speed to the target temperature is large and the heat capacity is large.
There is a disadvantage that power consumption is large. On the other hand, the drying method using only far-infrared rays has the disadvantage that the rate of starting up to the target temperature is slow, and baking unevenness is easily generated in the coating film. However, it has the advantages of energy saving and a clean heat source. There is.

On the other hand, the baking drying furnace 5 according to the present invention
At the start of operation, the electric heater 58 is turned on at the start of operation, and the inside of the furnace is heated by the hot air circulation device 60.
The furnace temperature can be quickly raised to the target temperature, and the waiting time at the start of operation can be shortened. The baking and drying furnace 5 has a high effect of confining hot air as described above, and since the work is preheated by the preliminary drying furnace 4, the temperature in the furnace does not decrease after reaching the target temperature in the furnace. Few. Therefore, after the furnace temperature approaches or reaches the target temperature, the far infrared ray is radiated by the far infrared ray generator 56 to directly heat the work, thereby compensating for the temperature decrease of the baking / drying furnace 5 and the temperature distribution. It suffices if it is controlled so as to be uniform, and the energy consumption can be extremely reduced. Further, the temperature in the baking / drying furnace 5 is detected by a temperature sensor 57 and a plurality of far-infrared ray
By controlling the temperature, the temperature in the furnace can be made uniform as shown in FIG. 13, so that the work can be baked and dried at a uniform temperature.

Further, in the baking / drying furnace 5, since the air is circulating in the baking / drying furnace 5 and does not blow out from the work carrying-out port 7, the hot air in the baking / drying furnace 5 rises and the upper part of the furnace is heated. Therefore, the hot air does not escape to the outside from the work carry-out port 7 opened on the bottom surface of the baking / drying furnace 5, and the effect of confining the hot air in the baking / drying furnace 5 is very high.

Further, the far-infrared ray generator 56 directly heats the work, and at the same time, the air in the baking oven 5 is agitated by the blower fan 59. In some cases, the hot air circulation device 6 is used.
Since the atmosphere heating by 0 is also used, the atmosphere temperature in the furnace is kept uniform, and it is possible to prevent unevenness in the work from occurring when the work is baked and dried by the far-infrared ray generator 56 alone, thereby improving the product quality. Can be done.

Further, when heating is performed by the far-infrared ray generating device 56, the blowing of the blowing fan 59 is stopped,
If the amount of air blow is reduced, dust is less likely to be formed, and the defective product rate of the work can be reduced.

When the work carrier 2 is moved from the preliminary drying furnace 4 to the baking drying furnace 5, the partition plate 11 between the preliminary drying furnace 4 and the baking drying furnace 5 is opened. The plate 11 is closed as shown in FIG. Therefore, as shown in FIG. 13 showing the change in the furnace temperature between the preliminary drying furnace 4 and the baking drying furnace 5, the temperature change between the preliminary drying furnace 4 and the baking drying furnace 5 becomes steep, Both the temperature distribution in the drying oven 4 and the temperature distribution in the baking drying oven 5 can be made uniform.

(Others) In the above-described embodiment, the work carry-in port 6 and the work carry-out port 7 are provided on the lower surfaces of the skirt portions 9 and 10 respectively hanging from the bottom surfaces of the preliminary drying furnace 4 and the baking drying furnace 5. Skirt part 9,1
The work inlet 6 and the work outlet 7 may be provided on the bottom surfaces of the predrying furnace 4 and the baking / drying furnace 5 without providing 0. That is, the work inlet 6 and the work outlet 7 may be provided at the same height as the bottom surfaces of the preliminary drying furnace 4 and the baking / drying furnace 5. However, when the skirts 9 and 10 are not provided, if wind blows across the lower surfaces of the work entrance 6 and the work exit 7, the hot air in the predrying furnace 4 and the baking drying furnace 5 is drawn by the negative pressure. The skirt portions 9 and 10 are preferably provided in an environment where wind is generated since the skirt portions 9 and 10 are pulled out and leaked to the outside. Further, in order to prevent the hot air from being drawn out by the wind, it is preferable that the space below the skirt portions 9 and 10 is also enclosed except for the opening for loading or unloading the work.

In the above embodiment, the case of electrodeposition coating has been described. However, it goes without saying that the present invention can be applied to a drying apparatus for other uses.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a drying apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a state in which a work carrier is suspended from the drying device.

FIG. 3 is a cross-sectional view showing a structure of a portion taken along line XX of FIG. 2;

FIG. 4 is a cross-sectional view showing a structure of a portion taken along line YY of FIG. 2;

5A and 5B are a side view and a front view showing a structure of a slider engaged with a rail.

FIGS. 6A and 6B are a partially broken side view and a partially broken front view showing a feeder for moving the slider according to the first embodiment.

FIGS. 7A to 7D are schematic diagrams illustrating an operation of feeding a work transfer slider by the feeding device according to the first embodiment.

FIG. 8 is a schematic configuration diagram showing an air knife device used in the drying device of the above.

9A and 9B are diagrams showing an operation of the air knife device of the above, wherein FIG. 9A shows an opening and closing operation of an electromagnetic on-off valve on a compressor side, FIG. 9B shows an opening and closing operation of an electromagnetic on-off valve on an air nozzle side, (C) is a diagram showing a change in air pressure in the air tank.

FIG. 10 is a schematic cross-sectional view illustrating a drying device during drying of a workpiece.

FIG. 11A is a cross-sectional view showing details of a baking / drying oven,
(B) is a sectional view taken along the line ZZ of (a).

FIG. 12 is a diagram showing a control circuit of the far-infrared ray generator.

FIG. 13 is a diagram showing a distribution of an internal temperature in the drying device of the above.

FIG. 14 is a schematic cross-sectional view showing a state where a work carrier is fed below a work carry-in port.

FIG. 15 is a schematic cross-sectional view showing a state where the work carrier is lifted to the height of the rail by the rail-shaped elevating body.

FIG. 16 is a schematic cross-sectional view showing a state in which a work carrier is moved from a rail-shaped elevating body on the loading side to a rail.

FIG. 17 is a schematic cross-sectional view showing a state in which a work carrier is moved from a preliminary drying oven to a baking drying oven.

FIG. 18 is a schematic cross-sectional view showing a state in which a work carrier is moved from a rail to a rail-shaped elevating body on the unloading side.

FIG. 19 is a schematic cross-sectional view showing a state in which the work carrier is sent out from below the work outlet.

FIG. 20 is a schematic sectional view showing a conventional drying device.

FIGS. 21 (a) and (b) are views for explaining a transfer state in an inclined portion (work loading / unloading path) and a horizontal portion (drying furnace main body) of the drying device.

FIG. 22 is a diagram showing a distribution of an internal temperature in the drying device of the above.

[Explanation of symbols]

 2 Work Carrier 3 Furnace Rail 4 Predrying Furnace 5 Baking Drying Furnace 6 Work Inlet 7 Work Outlet 8 Drying Device Body 9 Skirt Part 10 Skirt Part 11 Partition Plate 14 Feeding Device 20 Feed Bar 22 Feeding Claw 28 Elevating Loading Device 29 Loading Lifter 30 Relay Rail 31 Loading Pusher 36 Lifting / Unloading Device 37 Loading Lifter 38 Relay Rail 39 Loading Pusher 41 Air Knife Device 44 Air Tank 46 Electromagnetic Open / Close Valve 47 Air Nozzle 49 Electromagnetic Open / Close Valve 53 Hot Air Circulation Device 54a Hot Air Circulating port 54b Hot-air outlet 55 Hot-air circulating duct 56 Far-infrared ray generator 57 Temperature sensor 58 Electric heater 59 Blow fan 60 Hot-air circulating device 61 Far-infrared radiation heater 66b Hot-air outlet 66a Hot-air circulating port 67 Hot-air circulating duct 68 Temperature sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location F27B 9/36 F27B 9/36

Claims (9)

[Claims] 1. A drying device, wherein the drying device body is provided with at least one of a work carrying-in port and a work carrying-out port, and the work carrying-in port or the work carrying-out port is opened on a bottom surface of the drying device body. 2. A work carry-in device or a work carry-out device for raising and lowering a work carrier holding a work in a substantially vertical direction and carrying in and out the work carrier from the work carry-in port or the work carry-out port. 1. The drying device according to 1. 3. The drying apparatus according to claim 1, wherein the work transfer body is moved in the horizontal direction by a transfer means capable of varying a distance between the work transfer bodies holding the work. 4. The drying device according to claim 1, further comprising a device that blows air onto the work by an air nozzle installed near the work carry-in port to remove water. 5. The drying device according to claim 1, further comprising a convection heating unit and a radiation heating unit. 6. The drying apparatus according to claim 5, wherein said means for heating by radiation is a plurality of far-infrared ray generating devices. 7. The drying apparatus according to claim 6, wherein the far-infrared ray generating device is divided into a plurality of sections, and the temperature is controlled for each section. 8. A hot-air circulation duct that connects the hot-air circulation port and the hot-air outlet that are opened in the dryer body, and the air discharged from the hot-air circulation port is heated and discharged from the hot-air outlet into the dryer body. The drying device according to claim 1, further comprising: a heater and a blower fan. 9. The drying apparatus according to claim 1, wherein a pre-drying oven and a baking drying oven are provided in series, and a communication port thereof can be opened and closed by a partition plate.