JPH069668B2 - Horizontal furnace - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a horizontal furnace for drying or baking a coating material applied to an object to be coated by heat treatment.

[Background Art] A furnace with a slanted entrance / exit of the furnace body (mountain-shaped furnace) has the advantage of less heat loss at the entrance / exit, but it is difficult to install if the ceiling of the factory building is low. However, there is a problem that it is difficult to convey the material in the furnace depending on the shape of the object to be coated. When such a problem occurs, a horizontal furnace having a horizontal furnace body is used.

However, the conventional horizontal furnace has a problem that even if an opening / closing door is provided at the entrance / exit, when the object to be coated is taken in and out, the furnace body is directly opened to the outside, so that heat easily escapes from the furnace body. However, there was a problem that the thermal efficiency was poor and the temperature distribution inside the furnace was not stable. It may be possible to provide an air curtain at the entrance and exit of the furnace body, but it is not practical in a furnace for baking an object to be coated, etc., because of poor thermal efficiency and inconvenience such as dust adhering to the object to be coated. Therefore, it has been desired to develop a horizontal furnace having high thermal efficiency and stable temperature distribution in the furnace.

Conventionally, a horizontal furnace is used, for example, in the baking process of an electrodeposition coating line having the process shown in FIG. In such a coating line, the objects to be coated are relatively large products such as automobiles and prefabs, and the monthly production is 5000.
In the case of a relatively small quantity production on the order of a table, as shown in FIG.
If 0 is used, the size of the entire line can be reduced and the cost can be reduced. FIG. 6 shows the steps from hot water washing to fifth water washing in FIG.
Is a hot water washing tank, 92 is a degreasing tank, 93 is a first water washing tank, 94 is a second water washing tank, 95 is a surface conditioning tank, 96 is a chemical conversion tank, 97 is a third water washing tank, 98 is a fourth water washing tank, 99 Is the 5th washing tank, 10
0 is a spray.

However, it was impossible to pass the hoist through the baking furnace in terms of heat resistance of the hoist. In addition, when passing the hoist outside the baking furnace, it is inevitable that a gap in the ceiling of the furnace body must be provided, resulting in a large heat loss, and the electric components of the hoist fail due to hot air leaking from the gap. There was a problem.

Therefore, conventionally, in the coating line as shown in FIG. 5, the object to be coated is transferred from the hoist to the conveyor or the like before the baking process. Therefore, the working time and the equipment cost are increased.

[Object of the Invention]

In view of the above circumstances, it is an object of the present invention to provide a horizontal furnace which can reduce the cost in a coating line, has high thermal efficiency, and has a stable temperature distribution in the furnace body.

[Disclosure of Invention]

In order to achieve the above-mentioned object, the present invention is a horizontal furnace for heat-treating an object to be coated, comprising a tunnel-shaped furnace body and heating means for heating the inside thereof. It has a processing chamber and waiting rooms arranged before and after it, and a rail is laid above the furnace body along the longitudinal direction of the furnace body. The automatic traveling hoist is suspended so that it can travel freely.
A suspender for suspending the object to be coated is hung on the hoist so that the object to be coated faces the furnace body, and the furnace body allows the suspender to pass through the ceiling portion over the entire length in the longitudinal direction. A groove is formed, a leak preventing means for preventing the atmosphere in the furnace from leaking to the outside through the groove is provided, and an inner door is provided between the main processing chamber and the front and rear waiting chambers. Outer doors are provided between the front and rear waiting rooms and the outside, and a control means for controlling the opening / closing operation of these doors and the running / stopping operation of the hoist is provided. , The doors inside and outside each waiting room control the opening / closing operation so that the other one is always closed when one is open, while the hoist adjusts the object to be coated according to the movement of each door. To the front waiting room The travel from putting once to the rear waiting room than the processing chamber and transferred to the processing chamber from to transfer to the external and
The gist is a horizontal furnace that is characterized by controlling the stopping operation.

Hereinafter, the present invention will be described in detail with reference to the drawings showing an embodiment thereof.

FIG. 1 schematically shows an embodiment of a horizontal furnace according to the present invention when viewed from the front, and FIG. 2 schematically shows it in a cross section taken along the line XX ′ in FIG. There is. As shown in these figures, this horizontal furnace is provided with a horizontally extending tunnel-shaped furnace body 1 and heating means 2 for heating the inside thereof. The inside of the furnace body 1 is divided into three chambers, a main treatment (heating) chamber 10 is arranged in the center, and a front waiting chamber 11 and a rear waiting chamber are provided at an inlet (front) and an outlet (rear) of the main treatment chamber 10. 12 are arranged. Main processing room 10 and waiting rooms 1 before and after
In this embodiment, the lengths of 1 and 12 are set such that the main processing chamber 10 has a length of 5 objects A to be coated and the front and rear waiting rooms 11 and 12 have a length of 1 object A to be coated. Has been
However, the present invention is not limited to this. For example, the front and rear waiting rooms 11 and 12 may have a length that allows two or more objects A to be coated. Main processing room 10 and waiting rooms 1 before and after
A front inner door 14 and a rear inner door 15 are respectively provided between the doors 1 and 12.
However, a front outer door 13 and a rear outer door 16 are provided between the front and rear waiting rooms 11 and 12 and the outside, respectively.

The heating means 2 has a hot air circulation fan 20 and a heater 21, and blows out the air heated by the heater 21.
2 into the main processing chamber 10, the air in the main processing chamber 10 is sucked from the suction duct 23 and sent to the heater 21, and is heated by the heater 21 and blown into the main processing chamber 10 again. It is supposed to be sent. In this way, the inside of the main processing chamber 10 is heated by the heating means 2 so that the hot air is circulated (hot air circulation type). Although not shown in FIG. 1, front and rear waiting rooms 1
1 and 12 are also heated in the same manner as the main processing chamber 10.
The processing temperature of each of these chambers 10, 11 and 12 is usually 80 to
It is in the range of about 250 ° C. For example, the temperature in the main processing chamber 10 is set to 160 to 180 ° C., and the temperatures in the front and rear waiting chambers 11 and 12 are set to 80 to 120 ° C. for use. Each room 10,
A temperature control means is attached to each of 11 and 12 in order to keep the temperature of each chamber at a predetermined temperature. Also, each room 1
Exhaust fans (exhaust means) 24, 25, and 26 are also provided at 0, 11, and 12, respectively, in order to keep the concentration of moisture and solvent evaporated in each chamber within the limits.

Above the furnace body 1, rails 3 are laid along the longitudinal direction. An automatic traveling hoist (hereinafter, referred to as “hoist”) 4 is suspended on the rail 3. As shown in FIG. 3, the hoist 4 includes a control panel 40, a traveling motor 41, four traveling rollers 42, a hoisting motor 4
3, a winding drum 44, and four traveling rollers 42
Is placed on the rail 3 so that it can be suspended and run freely. The traveling motor 41 uses the four traveling rollers 4
One of the two is rotated to drive the hoist 4. A hoisting tool 5 is suspended from the hoist 4. The hanging tool 5 includes two chains 50 and 51, a hanger 52, and a table 53 on which the article A to be coated is placed. One end of each of the chains 50 and 51 is fixed to the hoisting drum 44, and the other end thereof is a hanger 52.
It is connected to the. The base 53 is suspended from the hanger 52. The hanger 52 and the base 53 are made of a conductive material such as stainless steel. The winding drum 44 is
The winding motor 43 can be rotated forward and backward, and by this forward and reverse rotation, the chains 50 and 51 are wound and unwound, and the table 53 is moved up and down. The control board 40 includes a programmable controller (not shown) that can freely program driving and stopping of the traveling motor 41 and the hoisting motor 43. In other words, the programmable controller can automatically perform the operations of running, stopping, hoisting, and hoisting the hoist 4 at predetermined positions. Among these operations, the hanging and hoisting operations are utilized when dipping in a chemical conversion tank, an electrodeposition tank or the like in the steps such as chemical conversion and electrodeposition in FIG.

As shown in FIGS. 1 and 2, the lifting tool 5 suspended from the hoist 4 outside the furnace body 1 faces the inside of the furnace body 1 at the lower part of the hanger 52 and the platform 53. That is, the suspending tool 5 is suspended by the hoist 4 so that the article A to be coated faces the inside of the furnace body 1. In the furnace body 1, the hanger 5 of the hanger 5 is provided over the entire length in the longitudinal direction at the ceiling portion.
A groove 17 is provided to allow the upper part of 2 to pass.
Therefore, the width of the groove 17 is set to a width (about 50 to 70 mm) through which the upper part of the hanger 52 can pass. At the opening portion of the groove 17, there is provided a leakage preventing means for preventing the atmosphere inside the furnace from leaking to the outside through the groove. The leak preventing means is composed of a sheet-like seal 61 made of a heat-resistant resin such as PTFE (polytetrafluoroethylene) and an air seal 62. Reference numeral 620 is an air seal supply fan, and 621 is an air seal exhaust fan. This leakage preventing means prevents hot air in the furnace body 1 from leaking to the outside from the groove 17, and as a result, electronic parts and the like provided on the control panel of the hoist 4 provided above the groove 17 are hot air. It can prevent breakdown.

A cover 7 that protects the hoist 4 over the entire length of the furnace body 1 is provided in a portion where the hoist 4 travels, so that the hoist 4 does not fail due to hot air in the furnace body even when there is an abnormality such as a power failure. The inside of the cover 7 is cooled by the cool air sent by the cooling fan 71.

The hoist 4 is controlled so that the object A to be coated is first put in the front waiting room 11 and then moved to the main processing chamber 10, and once put in the rear waiting room 12 from the main processing chamber 10 and then moved to the outside. The doors 13, 14, 15, 16 are the same as those of the chambers 1.
It is designed to be opened when entering or exiting 0, 11, 12, and when the front outer door 13 is open, the front inner door 14 is always opened.
Is closed, and conversely, when the front inner door 14 is open, the front outer door 13 is always closed. Further, also in the rear inner door 15 and the rear outer door 16, the rear inner door 15 is always closed when the rear outer door 16 is open, and conversely, when the rear inner door 15 is open, the rear inner door 15 is always rear. The outer door 16 is designed to be closed.

Next, the above-mentioned transportation operation of the hoist 4 and each door 13, 1
FIG. 4 shows the relationship with the opening / closing operations of 4, 15, and 16.
A detailed description will be given with reference to (a) to (d).

As shown in FIG. 4 (a), the objects to be coated A _{1 to} A ₁₁ are conveyed by the hoist 4. Object A
Nos. _{9 to} A ₁₁ stand by in front of the furnace body 1 (front waiting room 11) for baking the paint applied by electrodeposition or the like. The coating object A ₁ is sent to the rear of the furnace body 1 (rear chamber 12) after the baking process is completed. Object A
₂ is placed in the rear waiting room 12. Object to be coated A _{3 to} A
₇ is contained in the main processing chamber 10. Object A
₈ is placed in the front waiting room 11. Each door 13, 14,
All of 15 and 16 are closed. After a certain time (for example, 2 minutes) has passed from this state, the rear outer door 16 is first opened as shown in FIG. 4 (b). Immediately, the hoist that suspends the article to be coated A ₂ moves, and the article to be coated A ₂ is transported from the rear waiting room 12 to the outside of the furnace body 1. Prior to this, the article A ₁ to be coated is moved backward by a predetermined program. As shown in FIG. 4 (c), the rear outer door 16
Is closed, and then the rear inner door 15 and the front inner door 14 are opened. Immediately, the hoist that suspends the objects to be coated A _{3 to} A ₈ moves, the objects to be coated A _{3 to} A ₈ are respectively transported rearward, and the objects to be coated A ₃ are transferred from the main processing chamber 10 to the rear waiting room 12. The object A ₈ to be coated is moved from the front waiting room 11 to the main processing room 10. From this state, as shown in FIG. 4 (d), the rear inner door 15 and the front inner door 14 are closed,
Then, the front outer door 13 is opened. Immediately
_The hoist that suspends _{9 to} A ₁₁ moves, and these coated objects A _{9 to} A ₁₁ are respectively conveyed to the rear, and the coated object A _9
9 is moved from the outside of the furnace body 1 to the front waiting room 11. Thereafter, as shown in FIG. 4 (a), the front outer door 13 is closed and one cycle is completed. Hereinafter, this cycle is repeated.

As can be seen from the above, the control means (controller) controls the opening / closing operation of each of the doors 13 to 16 and the conveying operation of the object to be coated A, with respect to the opening / closing operation of each of the doors 13 to 16, each waiting room 11 ,. The doors 13 to 16 inside and outside of 12 are controlled so that when one is open, the other is always closed.
Regarding the transfer operation of the object A to be coated, the object A to be coated is once put in the front waiting room 11 and then moved to the main processing chamber 10 in accordance with the movement of the respective doors 13 to 16 and then moved from the main processing chamber 10 to the rear waiting room 12. It is controlled so that it is put in once and then moved to the outside. In this way, the front inner and outer doors 13 and 14 are always closed when one is open, and the rear inner and outer doors 15 and 14 are closed.
As for 16 as well, when one is opened, the other is always controlled to be closed. Therefore, the inside of the main processing chamber 10 is not directly opened to the outside, and the heat of the main processing chamber 10 may escape to the outside. rare. Therefore, the thermal efficiency is good and the temperature fluctuation in the furnace body 1 can be reduced. Also, the furnace body 1
Grooves 17 are formed in the ceiling part of each door 13,1
Since the opening, closing, and closing of 4, 15, 16 are performed as described above, in the main processing chamber 10, the air flow blown into the groove from the door shown by the arrow Q in FIG. It is possible to suppress hot air that leaks through the outside.

The horizontal furnace is provided with a door opening / closing confirmation mechanism and a hoist stop position confirmation means as safety devices. Further, packing or the like is used to seal between the door and the furnace body. The number of objects to be coated in this processing chamber may be determined depending on the baking processing time.

The horizontal furnace according to the present invention is not limited to the above embodiment. The inside of the furnace does not have to be completely horizontal and may be slightly inclined. Heating does not depend on hot air, gas, kerosene,
It may be electric infrared rays or the like. The heating of the furnace body is not limited to the hot air circulation type, but a radiant tube (a high temperature gas of 350 to 450 ° C. is passed inside).
It may be an expression. The open / close door system may be a vertical slide open / close type or a left / right slide open / close type. The opening / closing drive may be an air cylinder type, an electric motor type, an electric cylinder type, or the like.

〔The invention's effect〕

As seen above, the horizontal furnace according to the present invention is a horizontal furnace for heat-treating an object to be coated, and includes a tunnel-shaped furnace body and heating means for heating the inside thereof, and the furnace body is
The interior has the main processing chamber and waiting rooms arranged in front of and behind it, and rails are laid along the longitudinal direction of the furnace body above the furnace body. An automatic traveling hoist that automatically performs is suspended so that it can travel freely, and a suspender for suspending the object to be coated is suspended in the hoist so that the object to be coated faces the furnace body. A groove is formed in the ceiling to allow the hanging device to pass over the entire length in the longitudinal direction, and a leak prevention unit is provided to prevent the atmosphere in the furnace from leaking to the outside through the groove, and Inner doors are provided between the main processing chamber and the front and rear waiting rooms, and outer doors are provided between the front and rear waiting rooms and the outside, and the opening / closing operation of these doors and the running / stopping of the hoist are performed. Controls to control movement It includes a stage, the control means,
The inside and outside doors of each waiting room control the opening / closing operation so that the other one is always closed when one is open, while the hoist adjusts the object to be coated according to the movement of each door. The following effects are obtained because the running / stopping operation is controlled so that it is first put in the front waiting room, then moved to the main processing room, and then once put in the rear waiting room from the main processing room and then moved to the outside. There is.

The loss of heat energy is reduced and the thermal efficiency is improved.

Since no air curtain is used, dust does not easily adhere to the object to be coated.

The temperature distribution inside the furnace is stable and product quality can be improved.

Since the automatic traveling hoist is used as the transfer means, it is possible to transfer a large product, and it is possible to perform processing such as drying or baking of a large object to be coated.

Since the automatic traveling hoist is used as the transfer means, it is possible to build a line that is consistent with other processes in the coating line, and it is not necessary to transfer the object to be coated on the conveyor etc. in front of this furnace, and the working time and equipment Costs can be reduced. Therefore, a significant cost reduction can be realized.

[Brief description of drawings]

FIG. 1 is a front view schematically showing an embodiment of a horizontal furnace according to the present invention, FIG. 2 is a sectional view taken along the line XX ′ of FIG. 1, and FIG. 3 shows a hoist and hoisting gear of the embodiment. 4A to 4D are explanatory views showing the relationship between the hoist carrying operation and the door opening / closing operation of the embodiment, and FIG. 5 is a process drawing showing an example of a coating line process, FIG. 6 is an explanatory view schematically showing an example of the coating line. DESCRIPTION OF SYMBOLS 1 ... Furnace body 2 ... Heating means 3 ... Rail 4 ... Automatic traveling hoist 5 ... Hanging tool 10 ... Main processing room 11 ... Front waiting room
12 ... Rear waiting room 13, 16 ... Outer door 14, 15 ... Inner door
17 ... Groove 61, 62 ... Leakage prevention means A ... Coated object

Claims (1)

[Claims] 1. A horizontal furnace for heat-treating an object to be coated (A), comprising a tunnel-shaped furnace body (1) and heating means (2) for heating the inside thereof. Inside is the main processing room (10)
It has a waiting room (11, 12) arranged in front of and behind it, and rails along the longitudinal direction of the furnace body above the furnace body.
(3) is laid, and an automatic traveling hoist (4) that automatically performs each operation of running and stopping is suspended movably on this rail, and a hoist for hanging the object to be coated is suspended on this hoist ( 5) is hung so that the object to be coated is exposed in the furnace body, and in the furnace body, a groove (17) is formed in the ceiling portion so that the suspending tool can pass over the entire length in the longitudinal direction. Leak prevention means (61, 62) for preventing the atmosphere from leaking to the outside through the groove is provided, and an inner door is provided between the main processing chamber and the front and rear waiting rooms.
(14,15) but outside doors between front and back waiting rooms and outside
(13, 16) is provided, and a control means for controlling the opening / closing operation of these doors and the running / stopping operation of the hoist is provided. While controlling the opening and closing operation so that the other is always closed when one is open, the hoist moves the doors in accordance with the movements of the doors and then once puts the object to be coated in the front waiting room. A horizontal furnace characterized in that the running / stopping operation is controlled such that the operation is moved to the main processing room, once put in the rear waiting room from the main processing room, and then moved to the outside.