JP2001263944A - Conveyor furnace for drying sheet-form material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conveyor furnace for drying sheet-form material which is capable of restraining the attachment of fine dust to the sheet-form material as much as possible even when a chain conveyor is employed, and capable of effecting the drying treatment of the material efficiently. SOLUTION: The conveyor furnace for drying the sheet-form material is provided in a furnace body housing 9 with an inside surrounding wall 21 for surrounding the upper part of an upper transfer passage 10a for the chain conveyor 10, and a ventilating passage 22 formed at one side of a space between the inside surrounding wall and the furnace body housing. A communication port 23 for communicating the ventilating passage 22 with the inside of the inside surrounding wall 21 is formed at the lower side of the conveyor chain 12 in the lower part of the inside surrounding wall 21. A fan 26 for ventilating air in the ventilating passage into a furnace chamber 25 in the inside surrounding wall is provided in the upper part of the ventilating passage 22. A furnace chamber filter 27 is arranged in the upper part of the furnace chamber while a distributing panel 28 is arranged in the lower part of the furnace chamber so as to cover the lower side of the upper transfer passage of the chain conveyor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet drying furnace for drying a sheet-like material, such as a thin printed circuit board, which has been subjected to a flexible printing process and is used in a clean atmosphere such as in a clean room. About.

[0002]

2. Description of the Related Art For example, in the case of drying a thin printed circuit board (sheet-like material) that has been subjected to a printing process, a tunnel-type drying furnace provided with a conveyor is used to continuously and efficiently perform a drying process. The drying process is continuously performed while the articles are conveyed by a conveyor in a drying furnace.

[0003] When drying a thin printed circuit board subjected to a printing process, it is necessary to minimize the adhesion of fine dust to the surface of the printed circuit board. In the case of a tunnel type drying furnace, a conveyor laid inside is required. Not a small amount of fine dust is generated from the sliding portion of the substrate and adheres to the printed circuit board, which adversely affects the product.

[0004]

For this reason, in the prior art, the adhesion of fine dust to the printed circuit board surface has been suppressed by using a beam conveyor or the like that generates as little dust as possible from the sliding portion. In some cases, a chain conveyor is used due to the structure of the production line. The chain conveyor has a relatively simple structure and has few failures as a transport device, and can be used easily.However, since there are many sliding parts, it generates a lot of dust and can be used for printed circuit boards that are to be dried. There is a problem that the adhesion of dust increases and the product is adversely affected.

The present invention has been made in view of the above points, and minimizes the adhesion of fine dust to a sheet-like material even when a chain conveyor is used, and efficiently removes the sheet-like material. An object of the present invention is to provide a conveyor for drying a sheet-like material that can be subjected to a drying treatment.

[0006]

In order to achieve the above object, a conveyor furnace for drying a sheet-like material according to the present invention comprises a plurality of crossing frames connected at regular intervals between conveyor chains on both sides, and each crossing frame has A chain conveyor in which a sheet-like material holding frame for holding a sheet-like material with clips is fixed, a furnace body housing arranged so as to surround an upper periphery of an upper conveying path of the chain conveyor with a heat insulating wall, and a furnace body. A heater for heating the inside of the housing, wherein the inner oven surrounding the upper conveying path of the chain conveyor is disposed in the furnace body housing, wherein the inner oven is provided with a heater for heating the inside of the sheet. A ventilation path is formed on one side between the heat insulating walls of the furnace housing, a heater is installed in the ventilation path, and a communication opening communicating between the ventilation path and the inside of the inner surrounding wall is provided below the inner surrounding wall. A blower for blowing air in the ventilation path into the furnace chamber in the inner surrounding wall is provided at an upper part of the ventilation path, a furnace chamber filter is disposed at an upper part of the furnace chamber, and a furnace chamber is provided. A diversion plate is provided at the lower part of the chain conveyor so as to cover the lower side of the upper conveying path, and the lower end of the inner surrounding wall and both ends of the diversion plate allow hot air in the furnace chamber to flow near the conveyor chains on both sides. It is characterized by comprising.

[0007]

With the sheet furnace for drying a sheet-like material having such a configuration, hot air generated in a ventilation path provided with a heater is blown into an upper portion of a furnace chamber in an inner surrounding wall by an operation of a blower.
It passes through the furnace chamber filter and flows downward in the furnace chamber. The hot air flowing downward in the furnace chamber passes between the sheet-like materials held by clips of the sheet-like material holding frame on the chain conveyor, flows downward, and dries the sheet-like material. And
The hot air that has flowed down hits the distribution plate at the bottom of the furnace chamber and is divided into the conveyor chains on both sides.The hot air flows near the conveyor chains on both sides by the guides at the lower end of the inner surrounding wall and both ends of the distribution plate. , Returns to the ventilation path again through the communication port and circulates.

Accordingly, the hot air flowing from above to below in the furnace chamber flows near the conveyor chains on both sides and returns to the ventilation path, so that fine dust generated by the conveyor chain is collected and filtered by the upper furnace chamber filter. And cleanliness in the conveyor furnace can be kept high.

Further, if the hot air flowing near the conveyor chains on both sides is configured to be exhausted through a filter outside the furnace housing by an exhaust fan provided outside the furnace housing, the air flowing near the conveyor chain can be obtained. Is
Since the air is exhausted to the outside by an exhaust fan provided outside and exhausted through a filter, fine dust generated by the conveyor chain can be captured by the filter.

[0010] Further, if a spacing plate is provided on one surface of the sheet holding frame so as to project an interval from an adjacent sheet holding frame, the sheet is transported without contact. If the space holding plate is covered with a soft member at the tip thereof, dust generation when the space holding plate hits the previous sheet-like material holding frame can be prevented.

[0011] Further, the conveyor chain in the lower conveying path of the chain conveyor is covered with a cover body, and an exhaust fan for sucking air in the cover body and exhausting the air to the outside is provided, and a filter is provided in the exhaust passage. Then, the fine dust generated by the conveyor chain of the lower transport path can be satisfactorily captured by the filter, and can be used in a clean room.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall front view of a drying apparatus for drying a sheet-shaped material S as a printed circuit board after printing. 1 is a carry-in device for carrying the printed sheet material S from a printing device (not shown) to the apparatus, and 2 is a device for feeding the sheet material S carried in by the carry-in device 1 into the sheet material holding frame 15 of the chain conveyor 10. It is an input section for performing.

Following the charging section 2, the sheet-like material S
An air drying unit 3 for drying is installed. Following the air drying unit 3,
A conveyor furnace 4 for drying the sheet material S by hot air is provided. Further, following the conveyor furnace 4, a cooling unit 5 for cooling the heated and dried sheet material S is arranged, and following the cooling unit 5, an unloading unit 6 for unloading the dried sheet material S is installed. . As shown in FIG. 1, the chain conveyor 10 is a conveyor that is laid horizontally from the input unit 2 to the unloading unit 6 so as to pass through the drying device horizontally, and a rotating shaft is disposed at a front end and a rear end. Chain sprockets are supported on both sides of the rotating shaft, and an endless conveyor chain (roller chain) 12 is stretched between the two pairs of chain sprockets.

As shown in the cross-sectional view of FIG. 2, the conveyor furnace 4 is formed by laying a chain conveyor 10 in a furnace housing 9 having both sides and upper and lower surfaces formed by heat insulating walls 9a. An inner surrounding wall 21 is disposed vertically and continuously along the longitudinal direction of the conveyor so as to surround the upper portion of the upper conveying path 10a of the chain conveyor 10 in the furnace housing 9. A ventilation path 22 is formed on one side between the inner surrounding wall 21 and the heat insulating wall 9 a of the furnace housing 9, and the chain conveyor 1 is provided in a furnace chamber 25 formed in the inner surrounding wall 21.
No. 0 upper transport path 10a is provided.

Continuing to the lower part on both sides of the inner surrounding wall 21,
Chain cover portions 21a and 21b are provided so as to cover the conveyor chain 12, and the chain cover portions 21a and 21b are provided.
a, that is, below the conveyor chain,
A communication port 23 is provided to communicate between the inside 2 and the inside of the inner surrounding wall 21. A heater 24 for heating is installed in a vertical ventilation path 22 formed on one side of the furnace body housing 9, and the air in the ventilation path 22 is provided above the ventilation path 22 with the inner surrounding wall 21. A blower 26 for blowing air into the furnace chamber 25 is provided. The blower 26 uses a centrifugal fan. The intake port of the casing opens to the ventilation path 22 side, and the exhaust port of the casing communicates with and is connected to the upper part of the inner surrounding wall 21. A plurality of heaters 24 and blowers 26 are installed at intervals in the longitudinal direction in the conveyor furnace 4.

Further, a furnace chamber 25 above the inner surrounding wall 21 is provided.
A filter holding portion 21c is formed therein, and a furnace chamber filter 27 is provided therein. A HEPA filter capable of catching fine dust is used for the furnace chamber filter 27, but a pre-filter 27a using glass fiber for catching relatively large dust is provided in front of the furnace chamber filter 27. Be placed. In the lower part of the furnace chamber 25, near the lower center of the upper transport path 10a of the chain conveyor 10, the upper transport path 10a
A flow dividing plate 28 is provided so as to cover the center of the plate from below.

By the operation of the blower 26, a downward air flow is generated in the furnace chamber 25, and this downward air flow is
A flow dividing plate 28 is provided for effectively flowing the downward air flow to the vicinity of the conveyor chain 12 on both sides. The flow dividing plate 28 is formed so that its central portion bulges upward and both sides are inclined downward, while the conveyor chain 10 a is covered by a cover body 29 in the lower transport path 10 b of the chain conveyor 10. The cover body 29 is divided into two sides and fixed to the lower side of the furnace housing 9, and the conveyor chains 10a on both sides are provided.
Cover around. Each cover body 29 is provided with an exhaust fan 30 that sucks air therein and exhausts the air to the outside, and a filter 31 is provided in an exhaust passage 32 thereof.

As shown in FIGS. 3 to 5, the chain conveyor 10 has a large number of crossing frames 14 between the conveyor chains 12, 12 on both sides.
, And a substantially U-shaped sheet-like material holding frame 15 is fixed on each of the transverse frames 14 with the opening portion facing upward. The sheet-like object holding frame 15 is
4 is provided with a vertical frame 15a on both sides thereof, and a horizontal frame 15b
Are horizontally connected and fixed, and the size of the opening is substantially equal to the size of the sheet material S held and conveyed there.

At least two pairs of clips 16 are attached to both sides of the sheet-like material holding frame 15 with the inside facing inward.
Here, in order to hold two kinds of sheet materials having different heights, two pairs of clips are provided on the upper side and one pair is provided on the lower side, and a total of three pairs of clips 1 are provided.
6 are provided. The clip 16 is formed so that a spring is provided between the holding members and the sheets are sandwiched at the tip by a spring force. One side of the base is fixed to the vertical frame of the holding frame 15, and the other base is subjected to the spring force. By pushing inward against the tip, the tip of the clip 16 is opened. The holding surfaces of the three pairs of clips 16 are attached so as to be located on substantially the same plane, and hold the edges of the sheet-like material S carried on the plane on both sides.

An anti-sway frame 17 is mounted on the horizontal frame 15b below the sheet-like material holding frame 15 to prevent the sheet-like material S held there from shaking. The anti-sway frame 17 has a V-shaped notch in the upper part, and the lower end of the sheet-like material S is inserted into the notch to prevent shaking. On the front side of the sheet holding frame 15, an interval holding plate 18 is provided so as to protrude in order to maintain an interval between adjacent holding frames. During the operation, the front end of the gap holding plate 18 is
However, the tip of the spacing plate 18 is covered with a soft member 18a in order to prevent dust from being generated.

Next, the operation of the conveyer furnace for drying a sheet-like material having the above configuration will be described. Printing is performed on a thin and flexible printed circuit board (sheet-like material S) by a printing device (not shown), and the printed sheet-like material S is sent to the loading unit 2 by the carry-in device 1, and is illustrated by the loading unit 2. The clip 16 is sent onto the sheet holding frame 15 in a state where the clip 16 is opened by using a carry-in conveyor and a clip opening / closing device which are not used. Thereafter, the clip 16 is closed, and the edge of the sheet S is Portion of the sheet-like object S
Is held by a holding frame 15 on the chain conveyor 10.

In this way, the sheet-like materials S are sequentially held on the chain conveyor 10 and are carried from the air drying unit 3 to the conveyor furnace 4, where the sheet S advances over ten minutes and more. Then, the sheet-shaped material S is dried by receiving hot air.

In the conveyor furnace 4, as shown in FIG. 2, a heater 24 and a blower 26 are operated, and the air heated by the heater 24 in the ventilation passage 22, that is, the hot air, is sucked by the blower 26 and surrounded by the inside air. Air is supplied into the furnace chamber 25 in the wall 21. At this time, when the hot air passes through the pre-stage filter 27a and the furnace chamber filter 27, large particles to fine dust contained therein are effectively captured.

The hot air that has passed through the furnace chamber filter 27 flows downward in the furnace chamber 25, and is held vertically and at intervals on the sheet holding frame 15 on the chain conveyor 10. , And the sheet material S is dried. At this time, since the lower end of the sheet-like material S is held by the anti-swing frame 17, the sheet-like material S does not oscillate and does not come into contact with the adjacent front and rear sheet-like materials S. The sheet S can be dried and processed without attaching.

The hot air that has flowed downward from above in the furnace chamber 25 hits a distribution plate 28 below the chain conveyor 10 and is diverted to both sides, from inside the chain cover portion 21a, around the conveyor chain 12, and Ventilation path 2 from communication port 23
Go inside 2. Then, the hot air that has returned to the ventilation path 22 is heated again by the heater 24, is sent into the furnace chamber 25 by the blower 26, and the hot air circulates.

As described above, since the hot air circulating in the furnace chamber 25 and the ventilation passage 22 by the operation of the blower 26 passes well around the conveyor chain 12, fine dust which is easily generated by the conveyor chain 12 is removed. By effectively collecting and guiding it to the filter 27, dust in the hot air can be efficiently and satisfactorily captured. During operation, the leading end of the spacing member 18 provided on the sheet holding frame 15 of the chain conveyor 10 hits the preceding sheet holding frame 15, but the leading end of the spacing plate 18 is covered with the soft member 18a. Therefore, it is possible to prevent dust from being generated. Therefore, the generation of dust can be suppressed as much as possible, and the degree of cleanness in the furnace chamber 25 can be kept high. Therefore, it is possible to favorably dry a sheet-like material such as a printed circuit board which is not likely to adhere to dust after printing. it can.

On the other hand, the lower conveying path 1 of the chain conveyor 10
0b is covered with a cover body 29, and the air in the lower part of the conveyor chain 12 is exhausted through a filter 31 by an exhaust fan 30, so that the fine dust generated by the conveyor chain 12 is removed by the filter 31. Thus, even when the present apparatus is installed in a clean room, it is possible to prevent the release of dust into the clean room.

FIG. 6 is an enlarged sectional view of a conveyor furnace according to another embodiment. In this example, the air flowing in the vicinity of the conveyor chain 12 in the upper transport path 10a of the chain conveyor 10 is supplied to the exhaust fan 40 like the lower transport path 10b.
Thus, a structure in which the gas is exhausted to the outside of the furnace housing 9 through the filter 41 and the exhaust duct 42 is adopted. In addition, about the structure similar to the said Example, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

That is, one of the conveyor chains 12 in the upper transport path 10a is covered by the chain cover 21a and the lower cover 28a, and the other conveyor chain 12 is covered by the chain cover 21b and the lower cover 28b. . The covers 21a, 21b, 28a, 28b are arranged continuously in the longitudinal direction, and the exhaust duct 43 is connected to the cover 21 at intervals. Those exhaust ducts 43
It is led out of the furnace housing 9 to the outside and connected to the intake side of an exhaust fan 40 installed outside. On the other hand, exhaust ducts 44 are connected to the cover body 29 covering the conveyor chain 12 on the lower transport path 10b of the conveyor at intervals, and each exhaust duct 44 is led out to the outside, and like the upper exhaust duct 43, Each exhaust fan 40 is connected to the intake side. A filter 41 is connected to an exhaust duct 42 connected to an exhaust port of the exhaust fan 40.

In the conveyor furnace shown in FIG. 6, the hot air heated by the heater 24 in the ventilation passage 22 is sucked by the blower 26 and sent into the furnace chamber 25 in the inner surrounding wall 21 in the same manner as in the above embodiment. Is done. When the hot air passes through the pre-stage filter 27a and the furnace chamber filter 27, fine dust is captured from large particles contained therein. The hot air that has passed through the furnace chamber filter 27 flows downward in the furnace chamber 25, and
On the upper sheet-like material holding frame 15, the sheet-like material S is allowed to flow down around the sheet-like material S held vertically and at intervals, and the sheet-like material S is dried. The hot air that has flowed downward from above in the furnace chamber 25 hits a distribution plate 28 below the chain conveyor 10 and is diverted to both sides, but the hot air that has passed below the cover bodies 28a and 28b is From the opening 45 to the ventilation path 22
The hot air that has entered the inside and returned to the ventilation passage 22
4, the air is blown into the furnace chamber 25 by the blower 26, and the hot air is circulated.

On the other hand, the hot air entering the chain cover portions 21a and 21b is exhausted by an exhaust fan 40 into an exhaust duct 43.
Side, passing around the conveyor chain 12,
The air enters the exhaust fan 40 from the exhaust duct 43. Further, a cover body 29 covering the conveyor chain 12 of the lower transport path 10b.
The air inside is also sucked into the exhaust fan 40 via the exhaust duct 44. Then, the air is exhausted from the exhaust side of the exhaust fan 40 to the outside via the exhaust duct 42 and the filter 41.
Therefore, in this embodiment, fine dust generated by the conveyor chain 12 is sucked out of the furnace body housing by the external exhaust fan 40 through the exhaust ducts 43 and 44, and is captured by the filter 41.

[0032]

As described above, according to the conveyor for drying a sheet-like material of the present invention, even when a chain conveyor is used, hot air flowing downward from above in the furnace chamber is
The air flows near the conveyor chains on both sides and returns to the ventilation path.At this time, the fine dust generated by the conveyor chains is collected and captured by the upper furnace chamber filter, or the hot air flowing near the conveyor chains on both sides is collected. Is sucked out of the furnace housing and captured by a filter provided outside, so that the cleanliness inside the conveyor furnace can be kept high, and sheets that do not like the adhesion of dust such as printed circuit boards after printing The substance can be dried well.

[Brief description of the drawings]

FIG. 1 is an overall front view of a drying apparatus provided with a conveyor for drying a sheet-like material according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along the line II-II of FIG.

FIG. 3 is an enlarged partial sectional view taken along the line III-III of FIG. 2;

FIG. 4 is a front view of a sheet holding frame of the conveyor.

FIG. 5 is a partially enlarged side view of a sheet-like material holding frame on a conveyor.

FIG. 6 is an enlarged sectional view of another embodiment.

[Explanation of symbols]

 4-Conveyor Furnace 9-Furnace Housing 10-Chain Conveyor 10a-Upper Conveying Path 12-Conveyor Chain 15-Sheet-Retaining Frame 16-Clip 21-Inner Surrounding Walls 21a and 21b-Chain Cover 22-Ventilation Path 23- Communication port 24-heater 25-furnace chamber 26-blower 27-furnace chamber filter 28-distribution plate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // F27D 7/04 F27D 7/04 F term (Reference) 3F034 NA03 NB01 NB12 3L113 AA02 AB02 AC08 AC35 AC42 BA34 DA01 4K050 AA05 BA17 CD06 CD17 CF06 CF16 CG10 4K063 AA09 AA15 DA26 5E343 AA02 AA11 AA33 ER33 FF09 GG11

Claims (5)

[Claims] 1. A chain conveyor in which a number of transverse frames are connected at regular intervals between conveyor chains on both sides, and a sheet-like material holding frame for holding a sheet-like material with a clip is fixed on each of the transverse frames. A sheet drying furnace for drying a sheet-like material, comprising: a furnace body housing disposed so as to surround an upper periphery of an upper conveying path of the chain conveyor with a heat insulating wall; and a heater for heating the inside of the furnace body housing. Inside the furnace housing, an inner surrounding wall surrounding the upper conveyor path of the chain conveyor is disposed, and a ventilation path is formed on one side between the inner surrounding wall and the heat insulating wall of the furnace housing. A communication port communicating with the ventilation path and the inside of the inner surrounding wall is formed below the conveyor chain at a lower portion of the inner surrounding wall, and the heater is installed in the ventilation path. Inside the ventilation path A blower for blowing air into the furnace chamber in the inner surrounding wall is provided, a furnace chamber filter is provided in an upper part of the furnace chamber, and a lower part of the upper part of the chain conveyor is provided in a lower part of the furnace chamber. A sheet-shaped sheet, wherein a flow dividing plate is provided so as to cover, and the lower end portion of the inner surrounding wall and both end portions of the flow dividing plate are configured to flow hot air in the furnace chamber near the both-side conveyor chain. Conveyor furnace for drying goods. 2. The hot air flowing in the vicinity of the conveyor chains on both sides is returned to the ventilation path through a communication port provided near a lower end of the inner surrounding wall. A conveyor furnace for drying a sheet-like material as described in the above. 3. The hot air flowing near the conveyor chains on both sides is exhausted through a filter outside the furnace housing by an exhaust fan provided outside the furnace housing. 2. The conveyor furnace for drying a sheet material according to 1. 4. The sheet-like material holding frame is erected on the chain conveyor at an interval, and one surface of the sheet-like material holding frame is spaced from an adjacent sheet-like material holding frame. The conveyor furnace for drying a sheet-like material according to claim 1, wherein a holding plate is protruded, and a distal end of the spacing holding plate is covered with a soft member. 5. A conveyer chain in a lower conveying path of the chain conveyor is covered with a cover, an exhaust fan for sucking air inside the cover and exhausting the air to the outside is provided, and a filter is provided in the exhaust passage. The conveyor furnace for drying a sheet material according to claim 1, 2 or 3, wherein: