JPH07126026A - Method for regulating heat quantity of heating furnace and apparatus therefor - Google Patents

Abstract

PURPOSE:To prevent an atmospheric temperature in a heating furnace from lowering by blowing off heated mixed air from blowoff nozzles and producing the convection in the upper part of the heating furnace. CONSTITUTION:This method for regulating the heat quantity of a heating furnace is to blow off mixed air containing blown in air mixed with heated air from blowoff nozzles 34 supported in a casing 32 so as to freely lift and lower, heat sheet glass 18 for windows, monitor the atmospheric temperature in a heating furnace and the radiant source temperature, regulate the height of the blowoff nozzles 34 so as to uniformize the heat quantities in the upper and lower parts determined by a monitored value thereof and change the upper atmospheric temperature and upper radiant source temperature in the upper part of the sheet glass 18 for windows.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a heating burner provided above a carrying roller for carrying a plate-like material such as a window glass, and a heating heater provided below the carrying roller.
The present invention relates to a heat quantity adjusting method and apparatus for a heating furnace that heats a plate-shaped material with a heating burner and a heating heater.

[0002]

2. Description of the Related Art Generally, when a plate-shaped material such as a glass sheet for windows of an automobile is bent and formed, the plate-shaped material is heated in a heating furnace to a temperature at which it can be bent and formed before being bent and formed. in this case,
A roller hearth furnace is known as a heating furnace used. The roller hearth furnace includes a carrying roller, and the carrying roller is rotated by a drive motor. As a result, the plate-shaped material placed on the transport roller is carried into the roller hearth furnace. Further, in the roller hearth furnace, an upper heater is installed above the carrying roller, and a lower heater is installed below the carrying roller. Therefore, the plate-shaped material being conveyed in the roller hearth furnace by the conveyance rollers is heated from above by the radiant heat of the upper heater and at the same time from below by the radiant heat of the lower heater to a temperature at which bending can be performed. .

By the way, since the plate member is placed on the conveying roller, the lower surface of the plate member is in contact with the conveying roller.
Therefore, the amount of heat of the transport roller is directly transmitted to the lower surface of the plate-shaped material, and the temperature of the lower surface of the plate-shaped material becomes higher than the temperature of the upper surface thereof, so that the plate-shaped material warps upward. As an example for solving this problem, an annular groove is formed on the outer periphery of the conveying roller at regular intervals to suppress the amount of heat directly transferred from the conveying roller to the lower surface side of the plate-shaped material, and The amount of heat absorbed by the lower surface and the upper surface of the plate-shaped material by injecting compressed air above the material to generate convection above the plate-shaped material and efficiently transfer the radiant heat of the upper heater to the upper surface of the plate-shaped material. Have been proposed to keep them uniform.

[0004]

However, when compressed air is used to generate convection above the plate-shaped material, the ambient temperature in the heating furnace is lowered. Therefore, since it becomes difficult to heat the plate-shaped material to a high temperature, it is difficult to heat the plate-shaped material to a high temperature by the conventional method while keeping the absorbed heat amounts of the lower surface and the upper surface of the plate-shaped material uniform. There is a problem.

Further, in order to keep the amount of absorbed heat of the lower surface and the upper surface of the plate-shaped material uniform, it is necessary to uniformly adjust the upper heat quantity generated above the plate-shaped material and the lower heat quantity generated below the plate-shaped material. Yes, this adjustment is generally performed by changing the ambient temperature in the heating furnace. However, since the amount of heat generated in the heating furnace is set by the ambient temperature and the radiation source temperature, when the amount of heat generated is adjusted only by the ambient temperature, the amount of heat generated is not accurately adjusted.

The present invention has been made in view of the above circumstances, and when the plate-shaped material is heated at a high temperature, the amount of heat absorbed by the lower surface and the upper surface of the plate-shaped material is kept uniform so that the plate-shaped material is not warped. An object of the present invention is to provide a heat quantity adjusting method and apparatus for a heating furnace that can prevent the heat quantity and accurately adjust the quantity of heat generated in the heating furnace.

[0007]

SUMMARY OF THE INVENTION According to the present invention, the air in a heating furnace is sucked into a casing, and the heating air from a heating burner and the mixed air in the casing are supported in the casing so as to be able to move up and down. The upper surface of the plate-shaped material being blown out from the blowout nozzle and being conveyed in the heating furnace by the conveyance roller is heated, and at the same time, the lower surface of the plate-shaped material is heated by the lower heating means provided below the conveyance roller. A step of monitoring the upper atmosphere temperature and the upper radiation source temperature above the plate-shaped material, and the lower atmosphere temperature and the lower radiation source temperature below the plate-shaped material, and the upper atmosphere temperature and the upper radiation source temperature A step of comparing the upper heat quantity obtained based on the lower heat quantity with the lower atmosphere temperature and the lower radiation source temperature, and the upper heat quantity is different from the lower heat quantity, Adjusting the height of the sledge, the step of changing the upper atmosphere temperature and the upper radiation source temperature so that the upper heat quantity becomes uniform with the lower heat quantity, a heat quantity adjusting method for a heating furnace, and It is a device for carrying out.

[0008]

According to the present invention, there is provided the casing in which the air outlet of the heating burner is housed and the suction port which opens into the heating furnace is formed, and the fan is provided in this casing. The fan mixes the suction air sucked into the casing through the suction port and the heated air blown into the casing from the heating burner in the casing. Further, a blow nozzle is supported by the casing so as to be able to move up and down, and the blow nozzle blows the mixed air mixed in the casing onto the upper surface of the plate-shaped member. The height of the blowout nozzle is adjusted by the elevating means.

Further, according to the present invention, the upper atmosphere temperature and the upper radiation source temperature above the plate material and the lower atmosphere temperature and the lower radiation source temperature below the plate material are controlled during heating of the plate material. The upper heat quantity obtained by monitoring and comparing the upper atmosphere temperature and the upper radiation source temperature is compared with the lower heat quantity obtained based on the lower atmosphere temperature and the lower radiation source temperature. Then, as a result of the comparison, when the upper heat amount is different from the lower heat amount, the height of the blowing nozzle is adjusted, and the upper atmosphere temperature and the upper radiation source temperature are changed so that the upper heat amount becomes equal to the lower heat amount.

As described above, since the heated mixed air is blown out from the blowing nozzle to generate convection in the upper part of the heating furnace, it is possible to prevent the ambient temperature in the heating furnace from lowering. Moreover, since the heat quantity is adjusted based on the ambient temperature and the radiation source temperature, the upper heat quantity can be accurately adjusted so as to be uniform with the lower heat quantity.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A heat quantity adjusting method and apparatus for a heating furnace according to the present invention will be described in detail below with reference to the accompanying drawings. 1 is a front view of a heating furnace to which a heat quantity adjusting device for a heating furnace according to the present invention is applied, FIG. 2 is a side view thereof, and FIG. 3 is an enlarged view of a main part of the heat quantity adjusting device for a heating furnace according to the present invention. . The heating furnace 10 includes a heating furnace main body 12, and the heating roller main body 12 includes the conveying roller 1
4 are provided. The transport roller 14 is connected to a motor 16 (see FIG. 2) so that the rotational force can be transmitted. Therefore, when the motor 16 is driven, the carrying roller 14 rotates, and the window glass 18 placed on the carrying roller 14 is rotated.
Are conveyed in the heating furnace 10 in the direction of the arrow in FIG.

A heater 20 for heating is provided below the conveying roller 14 as a lower heating means.
4 are provided with heating burners 22, 22 ... In this embodiment, the heater is used as the lower heating means, but the burner may be used to heat the window glass. In this example, a heater was used as the lower heating means in view of the fact that it is easy to widen the upper and lower limits of the lower heating amount. A heat quantity adjusting device 30 is provided between the heating burners 22, 22 ... And the conveying roller 14. The heat quantity adjusting device 30 includes a casing 32, a fan 38, blowout nozzles 34, 34, ... And an elevating means 36. Openings 32A, 32A ... (See FIG. 3) are formed on the upper surface of the casing 32, and the outlets 22A, 22A ... Of the heating burners 22, 22 ... Are fitted into the openings 32A, 32A.

A suction port 32B (see FIGS. 3 and 4) is formed at the center of the lower surface of the casing 32, and a fan 38 is rotatably supported in the casing 32 above the suction port 32B. There is. The fan 38 diffuses the intake air sucked from the inside of the furnace through the suction port 32B into the casing 32. As a result, the intake air sucked from the suction port 32B and the heated air blown from the air outlet 22A of the heating burner 22 are mixed in the casing 32.

Further, communication pipes 34A, 34A of the blowing nozzle 34 are movably supported in opening holes 32C, 32C ... Formed in the lower surface of the casing 32, and the communication pipes 34A, 34A have their lower ends at their lower ends. The nozzle 34B is attached. Therefore, the nozzle 34B can move in the vertical direction. Further, the nozzle 34B is connected to the communication pipes 34A, 3 and 3.
It communicates with the casing 32 via 4A. The outlet of the nozzle 34B is formed in a rectangular shape, and the outlet is opened so as to face the window glass sheet 18.

The blow-out nozzle 34 having such a structure
Are provided on the lower surface of the casing 32 at regular intervals so as to be able to move up and down.
Are integrally connected by a connecting rod (not shown). Therefore, the outlets of the outlet nozzles 34, 34 ... Are arranged on the entire upper surface of the window glass 18, so that the casing 3
The mixed air of the heated air and the intake air in 2 blows out the nozzle 3
When blown out from the outlets of the four nozzles 34B, 34B ..., The mixed air is blown over the entire upper surface of the window glass sheet 18.

Also, the shafts 38A, 3 of the lifting means 36,
8B is rotatably supported on the upper portion of the heating furnace body 12. A motor (not shown) is connected to the shaft 38A so as to be able to transmit a rotational force. Sprockets 40, 40 are fixed to both ends of the shaft 38A, and sprockets 42, 42 are fixed to both ends of the shaft 38B. A chain 44A is meshed with the one sprocket 40, 42, and a chain 44B is meshed with the other sprocket 40, 42.

As shown in FIG. 4, chains 44A and 44B
Is connected to the nozzle 34B on the right side, and the other ends of the chains 44A and 44B are connected to the nozzle 34B on the left side.
Is connected with. Therefore, when the motor is driven, the sprockets 40, 40 rotate via the shaft 38A, so that the sprocket 4 moves via the chains 44A, 44B.
2, 42 rotate. As a result, the sprocket 40,
The chains 44A and 44B meshing with 42 are wound around the sprockets 40 and 42 and rewound so that the blowout nozzles 34, 34 ... Therefore, the blowing nozzles 34, 3
4 ... can be adjusted to a predetermined height.

The operation of the heat quantity adjusting device for a heating furnace according to the present invention, which is constructed as described above, will be described. First, the heater 20 for heating is turned on, and the burners 22, 22 for heating are heated.
Activate ... Further, by operating the fan 38, the intake air sucked from the inside of the furnace and the outlet 2 of the heating burner 22.
The heated air blown from 2A is mixed in the casing 32, and the mixed air is mixed with the nozzle 34 of the blowout nozzle 34.
B, 34B ... are blown out from the outlets. This allows
The mixed air is blown onto the entire upper surface of the window glass sheet 18 being conveyed by the conveying rollers, and convection occurs on the upper surface of the window glass sheet 18. The lower surface of the window glass sheet 18 is heated by the radiant heat of the heating heater 20.

In this state, the motor of the elevating means 36 is driven to move the chains 44A and 44B to the sprockets 40 and 42.
Is wound up and rewound, and the blowout nozzles 34 are moved up and down to be positioned at a predetermined position. Thereby, the amount of heat absorbed by the upper surface of the window glass 18 is adjusted, and the amount of heat applied to the upper surface and the lower surface of the window glass 18 becomes uniform.

Next, a description will be given of a heat quantity adjusting method of the heating furnace which applies the same heat quantity to the upper surface and the lower surface of the window glass 18 by using the heat quantity adjusting device of the heating furnace. First, the upper heat amount dq _upper applied to the window glass sheet 18 from above the window glass sheet 18 is expressed by the following equation (1). dq _upper = dq _{(conv) upper} + dq _{(rad) upper} (1) where dq _{(conv) upper} : upper atmosphere heat quantity dq _{(rad) upper} : upper radiation heat quantity In this case, upper atmosphere heat quantity dq _{(conv) upper} is α (T _g
-Ta _(upper) ), and the upper radiation source heat quantity dq
_{(rad) upper} is represented by εσ (T _g ⁴ −TH _(upper) ⁴ ). Therefore, the upper heat quantity dq _upper is expressed by the following equation (2).

Dq _upper = α (T _g −T _{a (upper)} ⁴ ) + ε σ (T _g ⁴ −T _{H (upper)} ⁴ ) ... (2) where α is the flow velocity of the air blown toward the window glass. , A constant determined from the flow velocity of the air flowing over the window glass ε: a constant determined from the material such as the radiation source and the window glass σ: Boltzmann's constant T _g : the temperature of the window glass 18 _{Ta (upper)} : Upper atmosphere temperature _{TH (upper)} : Upper radiation source temperature Incidentally, the blowing nozzle 34 is a constituent member of the upper radiation source, and the upper radiation source temperature _{TH (upper)} changes as the blowing nozzle 34 moves up and down.

On the other hand, the lower heat quantity dq _lower applied to the window glass sheet 18 from below the window glass sheet 18 is expressed by the following equation (3). dq _lower = dq _{(conv) lower} + dq _{(rad) lower} (3) dq _{(conv) lower} : Lower atmosphere heat quantity dq _{(rad) lower} : Lower radiation source heat quantity In this case, lower atmosphere heat quantity dq _{(conv) lower} is α ( T _g
-T _{a (lower)} ), and the upper heat source heat quantity dq
_{(rad) lower} is represented by ^{_{εσ (T g 4 -T H (}} lower) 4). Therefore, the upper heat quantity dq _lower is expressed by the following equation (4).

Dq _lower = α (T _g −T _{a (lower)} ) + ε σ (T _g ⁴ −T _{H (lower)} ⁴ ) ... (4) T _{a (lower)} : Lower atmosphere temperature _{TH (lower)} : Lower Based on the radiation source temperatures (2) and (4), T _{a (upper)} , T _{H (upper)} ,
T a _(lower) and T _{H (lowe r)} the monitored following formula (4) upper heat dq _upper as shown in is equal to the lower heat dq _{lowe r} As upper ambient temperature T _{a (upper),} the upper The temperature of the radiation source temperature _{TH (upper)} is controlled.

Dq _upper = dq _lower ...
(5) As a result, the same amount of heat is applied to the upper surface and the lower surface of the window glass plate 18. That is, for example, the conveying speed of the window glass 18 and the window glass 1 placed on the conveying roller 14
If the amount of absorbed heat of the window glass panes 18, 18, ..., Which is being conveyed in the heating furnace 10 is changed due to a change in the interval between the eight glass sheets, etc., the upper portion is provided so as to give an appropriate amount of heat to the window glass panes 18, 18 ,. It is necessary to control the heat quantity dq _upper and the lower heat quantity dq _lower .

In this case, since the heat quantity is directly transmitted from the conveying roller 14 to the lower surface of the window glass 18, 18 ,.
When the convection is generated by the compressed air blown toward the upper surface of the window glass 18 as in the related art, the atmospheric temperature is lowered by the compressed air. Therefore, when the lower heat quantity dq _lower is low, the upper heat quantity dq _upper can be controlled so that the relationship of dq _upper = dq _lower is established, but when the lower heat quantity dq _lower is high, dq _upper = dq _lower The upper heat quantity dq _upper cannot be controlled so that the relationship is established.

However, the heat quantity adjusting device for a heating furnace according to the present invention does not use compressed air, but blows out the nozzles 34B, 34B ...
Blowing mixed air (warm air) onto the upper surface of the window glass 1
Since convection is generated on the upper surface of the window glass 8, it is possible to prevent the atmospheric temperature above the window glass sheet 18 from decreasing. Therefore, even if the lower heat quantity dq _lower is high, dq _upper = d
The upper heat quantity dq _upper can be controlled so that the relationship of q _lower is established. That is, according to the heat quantity adjusting device for a heating furnace according to the present invention, even when the lower heat quantity dq _lower is high, the monitored T _{a (upper)} , T _{H (upper)} , T _{a (lower)} are monitored.
And the value of T _{H (lower)} , the blowing nozzle 3 is adjusted so that the upper heat quantity dq _upper becomes equal to the lower heat quantity dq _lower.
By adjusting the height of 4, 34 ..., the upper atmosphere temperature T
It becomes possible to control the values of _{a (upper)} and the upper radiation source temperature _{TH (upper)} . As a result, the same amount of heat is applied to the upper surface and the lower surface of the window glass plate 18.

In the above embodiment, the heights of the blowing nozzles 34, 34 ... Are adjusted to control the values of the upper atmosphere temperature T _{a ( upper)} and the upper radiation source temperature T _{H (upper).} However, the upper atmosphere temperature T _{a (upper)} and the upper radiation source temperature T _{H (upper)} may be controlled by other methods such as adjusting the combustion state of the heating burner 22. In the above embodiment, the case where the heat quantity adjusting device for a heating furnace according to the present invention is used to uniformly control the quantity of heat absorbed by the upper surface and the lower surface of the window glass 18 for an automobile has been described. However, the present invention is not limited to this, and it may be used for a glass other than the windshield or a plate-shaped material made of other material such as synthetic resin.

[0028]

As described above, according to the method and apparatus for adjusting the heat quantity of the heating furnace according to the present invention, the suction air sucked into the casing and the heating air blown from the heating burner into the casing are provided. Are mixed and blown out onto the upper surface of the plate-shaped material from a blow-out nozzle supported by a casing so as to be able to move up and down. This heats the plate-shaped material. Then, while heating the plate-shaped material, the upper atmosphere temperature and the upper radiation source temperature above the plate-shaped material and the lower atmosphere temperature and the lower radiation source temperature below the plate-shaped material are monitored, and based on these monitor values. The upper heat quantity and the lower heat quantity obtained by the above are compared. As a result of the comparison, when the upper heat quantity is different from the lower heat quantity, the height of the blowing nozzle is adjusted to change the upper atmosphere temperature and the upper radiation source temperature so that the upper heat quantity becomes equal to the lower heat quantity.

As described above, since the heated mixed air is blown out from the blowing nozzle to generate convection in the upper part of the heating furnace, it is possible to prevent the ambient temperature in the heating furnace from lowering. Further, since the heat quantity is adjusted based on the ambient temperature and the radiation source temperature, the upper heat quantity can be accurately adjusted so that the lower heat quantity becomes uniform. Therefore, when the plate-shaped material is heated to a high temperature, the amount of absorbed heat of the lower surface and the upper surface of the plate-shaped material are kept uniform, so that the plate-shaped material can be prevented from warping.

[Brief description of drawings]

FIG. 1 is a front view of a heating furnace to which a heat quantity adjusting device for a heating furnace according to the present invention is applied.

FIG. 2 is a side view of FIG.

FIG. 3 is a bottom view of a heat quantity adjusting device for a heating furnace according to the present invention.

FIG. 4 is a schematic perspective view of a heat quantity adjusting device for a heating furnace according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Heating furnace 14 ... Conveying roller 18 ... Window glass (plate material) 20 ... Heating heater 22 ... Heating burner 22A ... Heating burner outlet 30 ... Heating furnace heat quantity adjusting device 32 ... Casing 32B ... Suction Mouth 34 ... Blowout nozzle 34B ... Blowout port 36 ... Elevating means 38 ... Fan

Claims (2)

[Claims] 1. The air in the heating furnace is sucked into the casing, and the heated air from the heating burner and the mixed air in the casing are blown from a blowout nozzle supported by the casing and conveyed. A step of heating the upper surface of the plate-shaped material being conveyed in the heating furnace by a roller, and at the same time heating the lower surface of the plate-shaped material by a lower heating means provided below the transfer roller; A step of monitoring an upper upper atmosphere temperature and an upper radiation source temperature, and a lower atmosphere temperature and a lower radiation source temperature below the plate-shaped material, and an upper heat amount obtained based on the upper atmosphere temperature and the upper radiation source temperature And a step of comparing the lower heat quantity obtained based on the lower atmosphere temperature and the lower radiation source temperature; and, when the upper heat quantity is different from the lower heat quantity, adjusting the height of the blowing nozzle, And a step of changing the upper atmosphere temperature and the upper radiation source temperature so that the upper heat quantity becomes uniform with the lower heat quantity. 2. A heating burner is provided above a carrying roller for carrying a plate-shaped material in a heating furnace, and a lower heating means is provided below the carrying roller, and the heating burner and the lower heating means serve as the heating means. In a heat quantity adjusting device for a heating furnace that heats an upper surface and a lower surface of a plate-shaped material, a casing in which a blower outlet of the heating burner is housed and a suction port opened in the heating furnace is formed, and a casing provided in the casing. A fan that sucks the air in the heating furnace into the casing, mixes it with the heating air blown into the casing from the heating burner, and blows it out; A blowout nozzle that is opened to face the upper surface of the plate-like member and blows out the air blown out from the fan to the upper surface of the plate-like member, and an elevating hand that raises and lowers the blowout nozzle. If, heat adjustment device of a heating furnace equipped with.