JP2000081918A - Heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater reducing the number of controllers and capable of uniforming the temperature of a plate. SOLUTION: A main heater 2 and a main sensor 4 for measuring the temperature of the center part of a plate 1 are arranged on the center of the flat surface of the plate 1. A side part heater 3 and a side part sensor 10 for measuring the temperature of a part near to the side face of the plate 1 are arranged on the outer edge part of the flat surface of the plate 1. A control means 6 for obtaining a temperature signal 5 from the sensor 4 is connected to the sensor 4. A heater output means 8 for outputting physical quantity 9 to the heater 2 in accordance with a control signal 7 from the control means 6 is connected to the means 6. A heat radiation quantity adding means 12 for adding side face heat radiation quantity calculated based on a temperature signal 11 outputted from the sensor 10 and a signal 16 outputted from the control means 6 to the plate 1 is connected to the sensor 10. A heater output means 14 for outputting physical quantity to the heater 2 in accordance with a heat value signal 13 outputted from the means 12 is connected to the means 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device for uniformly heating glass or the like in a plane.

[0002]

2. Description of the Related Art FIG. 9 shows a conventional heating device using a cartridge heater. As shown in this figure, in the conventional heating device, a plurality of cartridge heaters 2
2a to 22e are inserted, and the control means 6 refers to the temperature signal 5 obtained by one temperature sensor 24 so that the temperature of the temperature sensor 24 becomes a predetermined temperature such as a current amplifier for driving a heater. The heater output command was sent to the heater output means 8. The heater output means 8 controls the temperature of the flat plate 1 by applying a current to all the cartridge heaters simultaneously according to this command.

There is also a method in which a plurality of plate-like heater blocks are spread on one surface of a flat plate to control the temperature distribution on the entire flat plate. FIG. 11 shows a conventional heating device for realizing this method. In the heating device shown in this figure, nine plate-shaped heater blocks are spread on the flat plate 1, and a control loop such as a temperature sensor, a control unit, and a heater output unit is provided for each heater block. There are nine control loops, the same number as the heater blocks. However, in FIG. 11, the control loop is 4
Only one is shown and the others are omitted. In this device, control means 6a, 6b, 6c,.
6d is a temperature sensor 2 for each heater block.
The heater output means 8 for each heater block is referred to by referring to the temperature signals obtained at 4a, 24b, 24c,.
a, 8b, 8c,.
By controlling the temperatures of a, 22b, 22c,... 22d, the temperature distribution over the entire surface of the flat plate 1 is controlled.

In the former method, the temperature is measured at one point, and each heater generates the same heat so as to control the temperature at that point. The temperature decreases due to the influence. For example, 400
200 ° C for aluminum alloy flat plate of mm square
In the vicinity, a temperature distribution of ± 5 ° C. or more, and in the vicinity of 400 ° C., a temperature distribution of ± 10 ° C. or more occurs.

In the latter method, the temperature distribution can be reduced, but it is necessary to install a control loop such as a temperature sensor and control means for each block, so that the apparatus is inevitably complicated and large. For example, a 400 mm square flat plate is 50 mm
If you try to control the temperature for each corner heater block,
The temperature distribution can be suppressed to ± 5 ° C. or less, but there are a total of 64 blocks, and correspondingly 64 control loops are required.

On the other hand, for example, glass used for a display or the like often undergoes a heating step in the process of manufacturing the display, and at that time, processing, element formation, assembly and the like are performed at a predetermined position on the glass. In addition, it is necessary to prevent deformation of the glass due to heat, increase the positional accuracy, and improve the processing accuracy and the assembly accuracy. For that purpose, it is necessary to heat the glass using a flat plate having a temperature distribution as small as possible in a heating device.

When a display pixel or a light filter is formed on glass, since the positional accuracy of each pixel or filter greatly affects the quality of the display image, the pixels and filters are formed. The glass serving as the substrate must not have a large thermal deformation due to a positional error factor, that is, uneven temperature or temperature gradient.

For example, when the glass plate is heated from 20 ° C. to 220 ° C., when the length of L = 400 mm, the thermal expansion coefficient of the glass is α = 10 × 10 ⁻⁶ and ΔT × L × α =
(220-20) × 400 × (10 × 10 ⁻⁶ ) = 800
Expand by μm. At this time, there is a temperature distribution (uneven),
If there is a temperature gradient of 20 ° C. at a length of 0 mm, ΔT × L ×
α / 2 = 20 × 400 × 10 ⁻⁶ / 2 = 40 μm,
A position shift of 40 μm occurs when the temperature is uniform. The temperature gradient needs to be 10 ° C. or less depending on the required accuracy of processing, element formation, assembly, and the like. If the temperature rises uniformly and the glass expands evenly, the position and desired position of each part of the glass surface after deformation can be predicted, but if irregular temperature unevenness or temperature gradient occurs, the glass becomes irregular or irregular. It deforms uniformly and makes it difficult to predict the position of the desired portion of the glass.

[0009]

However, in the above two types of heating devices, a plurality of cartridge heaters are inserted in a flat plate, and the same controller supplies the same current to all the heaters to raise the temperature ( (Apparatus of FIG. 10) The flat plate is divided into blocks, the temperature is detected for each block, and the output of the heater of each block is controlled by a controller corresponding to each block, thereby controlling the temperature distribution of the flat plate ( Therefore, there are the following disadvantages.

[0010] A single controller cannot reduce the temperature distribution. If the temperature is controlled by the controller for each block, the temperature distribution is reduced, but the apparatus becomes complicated and large, and the cost increases. In view of such a problem, an object of the present invention is to provide a heating device capable of reducing the number of controllers and making the temperature of a flat plate uniform, that is, reducing the temperature distribution.

Specifically, a first object of the present invention is to provide a heating device in which a heater is arranged so as to compensate for heat radiation from the side surface of a flat plate, the number of controllers is reduced, and the temperature of the flat plate is made uniform. That is.

A second object of the present invention is to provide a heating apparatus which makes the temperature of a flat plate even in a flat plate having a rectangular shape.

A third object of the present invention is to provide a heating apparatus for detecting the amount of heat radiated from the side surface of a flat plate and supplying the same amount of heat from the side heater as the amount of heat radiated from the side surface to reduce the temperature distribution of the flat plate. It is to be.

[0014]

According to a first aspect of the present invention, there is provided a heating apparatus for heating a flat plate, wherein the heating device heats a portion near a side surface or an outer peripheral portion of the flat plate. Side heater, a main heater located at the center of the flat plate, control means for controlling the output of the main heater, and a heat radiation amount adding means for making the output of the side heater equal to the heat radiation amount from the side surface of the flat plate. And characterized in that: In the above configuration, the side heater that heats the vicinity of the side surface or the outer peripheral portion of the flat plate inputs heat so as to compensate for the amount of heat released from the side surface of the flat plate, thereby reducing the temperature distribution of the flat plate.

According to a second aspect of the present invention, in the heating apparatus of the first aspect, the flat plate is rectangular, the heater is a cartridge heater, and one or more cartridge heaters are provided at the center of the flat plate. A heater is arranged, and another cartridge heater is arranged as a side heater on the four sides of the rectangular flat plate, so that the controller can be set to five to control the main heater and the four side heaters, or to the four sides. By controlling some of them at the same time, the temperature distribution is reduced to less than 5 so that the temperature distribution is reduced.

Further, according to a third aspect of the present invention,
In the heating device according to the first or second aspect, at least one main sensor disposed in an area of the flat plate where the main heater exists, and at least one side sensor disposed in a portion of the side heater. Further comprising
The heat radiation amount adding means converts the output of the side heater into the heat radiation amount from the side surface of the flat plate (heat transfer coefficient from the side surface of the flat plate to the outside air) × (the area of the side surface) × (the temperature between the flat plate side portion and the outside air). Difference), the number of controllers can be reduced as compared with the prior art, and the temperature distribution of the flat plate is reduced because the side heater inputs the heat so that the amount of heat is compensated for from the side surface of the flat plate. be able to.

According to a fourth aspect of the present invention, in the heating device according to the first or second aspect, at least one main sensor disposed in an area of the flat plate where the main heater exists, and At least one side sensor disposed at a side heater portion, wherein the heat radiation amount adding means includes a heat flow toward a side surface calculated from a temperature of the side sensor and a temperature of the main sensor. By predicting the amount of heat radiation from the side from the above, by compensating the amount of heat radiation with the output of the side heater, it is possible to reduce the number of controllers than before, and the side heater supplements the amount of heat radiation from the side surface of the flat plate As described above, since the heat is supplied, the temperature distribution of the flat plate can be reduced.

According to a fifth aspect of the present invention, in the heating device according to the first or second aspect, at least one main sensor disposed in an area of the flat plate where the main heater is present, At least one side sensor disposed at a side heater portion, wherein the heat radiation amount adding means is configured to make the temperature of the side sensor equal to the temperature of the main sensor, and thereby dissipate the heat from the side surface. , The number of controllers can be reduced compared to the related art, and the temperature distribution of the flat plate can be reduced because the side heater inputs heat so as to compensate for the heat radiation from the side surface of the flat plate.

In the case of heating glass, for example, by using the heating device having the above-described structure, the temperature distribution is reduced, and the thermal deformation of the glass is reduced. As a result, when processing, assembling, or forming an element on glass at a high temperature, errors in the position are reduced due to less deformation of the glass, and good processed and assembled products with high accuracy are obtained. Or a formed product could be supplied.

In particular, when pixels are formed on the glass used for the display, the glass expands uniformly, and if the pixels are formed uniformly according to the deformation, the glass and the pixels on the glass are uniform even after the temperature drops. As a result, non-uniform thermal expansion and deterioration of image quality due to thermal contraction could be prevented. Also, when combining a plurality of glasses with high accuracy, the thermal deformation of each glass can be reduced, so that the positional accuracy between the glasses can be improved.

With such a configuration, the temperature unevenness of the flat plate of the heating device can be suppressed to within 10 ° C. at around 400 ° C., and the accuracy of the heated glass is also reduced to ± 10 μm. In particular, when a flat plate of an aluminum alloy is used, the temperature unevenness is 40%.
It was possible to keep the temperature around 5 ° C at around 0 ° C.

As described above, since not only the temperature of the flat plate of the heating device and the temperature of the object to be heated become uniform, but also the thermal deformation of the object to be heated can be minimized, the processed product having good positional accuracy can be obtained. , Assemblies and formed products.

Further, although the number of controllers varies depending on the configuration, the temperature distribution can be reduced by approximately 1/5 to 1/10 or less, so that the apparatus is simplified, and the controller is not used. Costs were significantly reduced.

[0024]

Next, embodiments of the present invention will be described with reference to the drawings. In the drawings described below, the same components as those in the related art are denoted by the same reference numerals.

(First Embodiment) First, a basic embodiment of the present invention will be described with reference to FIG.

FIG. 1 is a view showing a heating device according to a first embodiment of the present invention. In this type of heating device, FIG.
As shown in FIG. 1, a main heater 2 is installed at the center of the flat plate 1, inside the flat plate 1, or outside the surface or near the surface. At the outer edge of the flat plate 1, a side heater 3 is provided inside, on the surface of, or outside near the surface of the flat plate 1.
Is installed. A main sensor 4 for measuring the temperature at the center of the flat plate 1 is provided at the center of the flat plate 1. Control means 6 for obtaining a temperature signal 5 from the main sensor 4 is connected to the main sensor 4. A heater output means 8 for outputting a physical quantity 9 to the main heater 2 in accordance with a control signal 7 from the control means 6 is connected to the control means 6.

A side sensor 10 for measuring the temperature near the side surface or the outer edge of the flat plate 1 is provided at the outer edge of the flat plate 1. The side sensor 10 has a heat quantity emitted from the side surface of the flat plate calculated based on the temperature signal 11 from the side sensor 10 and the signal 16 from the control means including the temperature signal 5 obtained from the main sensor 4. The heat radiation amount adding means 12 to be added to the flat plate is connected. A heater output means 14 for outputting a physical quantity 15 to the side heater 10 in accordance with a heat quantity signal 13 from the heat dissipation quantity adding means 12 is connected to the heat dissipation quantity adding means 12. The flat plate 1 is supported by a support member (not shown).

In the above configuration, the control means 6 controls the amount of heat generated by the main heater 2 by using, for example, PID control so that the temperature of the main sensor 4 becomes a preset temperature. When the control unit 6 issues a command to increase the amount of heat as the control signal 7, the heater output unit 8 changes the physical quantity 9 so that the main heater 2 increases the amount of heat. For example, when the amount of heat generated by the heater changes according to the magnitude of the current, such as a cartridge heater, the heater output means 8 is a current amplifier, and the physical quantity 9 is a current. Therefore, when receiving a control signal 7 for increasing the heat generation amount from the control means 6, the current amplifier as the heater output means 8 performs an operation to increase the current as the physical quantity 9 to reduce the heat generation amount of the main heater 2. Increase it. When the heater is inserted into or in contact with a flat plate like a cartridge heater or the like, heat is transferred from the heater to the flat plate mainly by heat conduction of the solid and heat transfer of the contact surface. On the other hand, when the heater is disposed outside the flat plate and is not in contact with the flat plate, such as a halogen heater, the heat is mainly transmitted from the heater to the flat plate by irradiation of the width and by heat conduction and convection of gas.

As described above, when the detected temperature of the main sensor 4 is higher than the set temperature, the amount of heat input is reduced, and when the detected temperature is low, the amount of heat input is increased. Can be controlled to a predetermined value.

Here, when the main heater 2 uniformly heats the flat plate 1, heat is released not only from the upper and lower surfaces of the flat plate 1 but also from the side surfaces. Therefore, the heat radiation amount adding means 12 refers to some of the signals 16 from the control means 6 including the temperature signal 11 obtained from the side sensor 10 and the temperature signal 5 obtained from the main sensor 4 to obtain a flat plate. The amount of heat radiation from the side of the side 1 is calculated, and the calorie signal 13 is sent to the heater output means 14 so that the side heater 3 inputs the amount of heat radiation. The heater output means 14 changes the physical quantity 15 in accordance with the heat quantity signal 13 and causes the side heater 3 to input a heat quantity equal to the heat radiation amount from the side surface. The physical quantity 15 is the aforementioned physical quantity 9
Is similar to As described above, since the side heater 3 supplies the heat amount substantially equal to the heat radiation amount from the side surface of the flat plate 1, the heat does not substantially flow in and out of the side surface of the flat plate 1. As a result, the main heater uniformly heats the flat plate and radiates heat only from the upper and lower surfaces, resulting in a thermally continuous and symmetrical state in the in-plane direction. It has become smaller. Although FIG. 1 shows a case where the heat radiation amount adding unit 12 refers to the temperature signal 11 and the signal 16, either one of them may be used. Further, the heat radiation amount adding means 12 can directly refer to the temperature signal 5.

Further, the side sensor 10, the heat radiation amount adding means 1
2, a series of means for compensating the amount of heat radiation from the side constituted by the heater output means 14, the side heater 3, and the like is one in this embodiment, but the side heater is further divided into several parts. , A plurality of similar means may be provided corresponding to each side heater.

The heating device according to the present embodiment has the following effects by adopting the above configuration.

The temperature difference between the flat plates of the heating device can be suppressed to within 10 ° C. around 400 ° C., and within 5 ° C. for the aluminum alloy flat plate.
A processed product, an assembled product, and a formed product having a good positional accuracy within 10 μm were able to be produced. At the same time, the number of controllers was reduced, and simplification of the apparatus and cost reduction were also realized.

(Second Embodiment) Here, an example in which a cartridge heater is used as a main heater and a side heater in the first embodiment will be described with reference to FIGS.

FIG. 2 is a diagram showing a heating device according to a second embodiment of the present invention, and FIG. 3 is a heater arrangement diagram in a flat plate surface for clarifying the positional relationship of the cartridge heater of FIG. In the heating device of this embodiment, as shown in FIG. 2, the main heaters 2a, 2b, and 2 serving as cartridge heaters are provided inside the flat plate 1 at the center of the flat plate 1.
c is inserted (see FIG. 3). Inside the flat plate 1 at the outer edge of the flat plate 1, side heaters 3a, 3b, 3c and 3d, which are cartridge heaters, are provided with rectangular flat plates 1.
(See FIG. 3). A main sensor 4 for measuring the temperature at the center of the flat plate 1 is provided at the center of the flat plate 1. Control means 6 for obtaining a temperature signal 5 from the main sensor 4 is connected to the main sensor 4. The control means 6 is connected to a heater output means 8 for outputting a physical quantity 9 to the main heaters 2a, 2b, 2c in accordance with a control signal 7 from the control means 6.

A side sensor 10 for measuring the temperature near the four side surfaces or the outer edge of the rectangular flat plate 1 at the outer edge of the flat plate 1
a, 10b, 10c, and 10d are provided. The side sensor 10a has a temperature signal 11 from the side sensor 10a.
The heat radiation amount adding means 12a for adding the amount of heat emitted from one side surface of the rectangular flat plate 1 calculated based on a to the flat plate is connected. Similarly, the side sensors 10b, 10c, 10
Heat radiation amount adding means 12b, 12c and 12d are connected to d, respectively. A heat output means 14 for outputting a physical quantity 15a to the side heater 10a in accordance with a heat quantity signal 13a from the heat dissipation quantity adding means 12a.
a is connected. Similarly, the heat radiation amount adding means 12b, 1
The heater output means 14b and 14d are respectively connected to 2c and 12d.
c and 14d are connected. The flat plate 1 is supported by a support member (not shown).

In the above configuration, the control means 6 controls the main heaters 2a, 2a by using, for example, PID control so that the temperature of the main sensor 4 becomes a preset temperature.
The amount of heat generated by b and 2c is controlled similarly to the first embodiment. When a control signal 7 for increasing the amount of heat generated by the heater is received from the control means 6, the current amplifier serving as the heater output means 8 performs an operation of increasing the current corresponding to the physical quantity 9 and the main heater 2a connected in parallel. , 2b, 2c, the flat plate 1 is heated almost uniformly. The heat generated from the heater is transmitted from the heater to the flat plate mainly by heat conduction of the solid and heat transfer of the contact surface, and the temperature of the flat plate rises. As described above, even when the cartridge heater is used as the main heater, the operation of reducing the heat generation amount of the main heater when the temperature of the main sensor 4 is higher than the setting and increasing the heat generation amount when the temperature of the main sensor 4 is low is conversely performed. By doing so, the temperature of the main sensor 4 can be controlled to a predetermined value.

In this embodiment, as shown in FIG. 2, for each side of the outer edge of the rectangular flat plate, the radiation from the side constituted by the side sensor, the heat radiation amount adding means, the heater output means, the side heater and the like. A series of means to supplement the heat is provided. The heat radiation amount adding means calculates the heat radiation amount from each side surface by the side sensor for each side, and issues a heat generation command to the side heater. As described above, since the respective side heaters supply a heat amount substantially equal to the heat radiation amount from the side surface of the flat plate 1, substantially no heat flows in and out of the side surface of the flat plate 1. As a result, the main heater uniformly heats the flat plate and radiates heat only from the upper and lower surfaces, resulting in a thermally continuous and symmetrical state in the in-plane direction. It has become smaller.

In FIG. 2, each heat radiation amount adding means sends a heat amount signal with reference to only one side sensor.
Other sensors or the like may be referred to. For example, the heat radiation amount adding means 12a refers only to the temperature signal 11a from the side sensor 10a, but refers to some of the other temperature signals 11b to 11d, the temperature signal 5 of the main sensor 4, and the like. Is also good.

Further, in this embodiment, as shown in FIGS. 2 and 3, a case where the number of cartridge heaters of the main heater is three is shown, but other numbers may be used. As the number of cartridge heaters increases, the distance between the heaters can be reduced, so that the temperature difference between a portion with a heater and a portion without a heater can be reduced.

Further, in this embodiment, since a cartridge heater is used as a heater, a heating device can be manufactured with a simple configuration in which the cartridge heater is inserted into a flat plate having a through hole or a deep hole, and processing and assembly can be performed. Cost was reduced. Other effects are the same as those of the first embodiment.

Here, a modification of the heating device of this embodiment is shown in FIG.
This will be described with reference to FIG.

In FIG. 2, the side sensors are provided on all four sides, but in FIG.
An example in which 0 is set is shown. In the heating device shown in FIG. 4, the main sensor 4, the control means 6, the main heater 2a
Operations such as to 2c are as described above with reference to FIG. However, in this modification, the heat radiation amount adding means 12 calculates the heat radiation amount from one side with reference to the side sensor 10,
Each of the side heaters 3a to 3d arranged on the four sides generates a heat amount equal to the heat radiation amount. In particular, when the flat plate has symmetry, the values of the respective side sensors 10a to 10d shown in FIG. 2 indicate approximate values, so that the temperature signal 11 from the side sensor 10 installed on a given arbitrary side is used. , The heat radiation amount calculated by the heat radiation amount adding means 12 is substantially equal on all sides. The heater output means 14 is connected to the side heaters 3a to 3d connected in parallel so as to compensate for this heat radiation.
An equivalent current is supplied to each of d, and an approximately equal amount of heat is supplied. As described above, the amount of heat radiation from the side surface obtained by referring to the temperature signal from the temperature sensor 10 is similarly supplied to each of the four side surfaces, so that the amount of heat radiation substantially equal to the amount of heat radiation from each side surface is obtained. Since the section heater is turned on, heat does not substantially flow in and out of the side surface of the flat plate. As a result, the main heater uniformly heats the flat plate and radiates heat only from the upper and lower surfaces, resulting in a thermally continuous and symmetrical state in the in-plane direction. It has become smaller.

The position where the side sensor 10 is installed may be different from the position shown in FIG. Further, side sensors may be provided on two or more sides.

(Third Embodiment) FIG. 5 shows a third embodiment of the present invention.
It is a figure explaining a heating device by an embodiment, and shows a portion, such as a side heater of a flat plate, a radiation amount addition means, and a side sensor, in a 1st embodiment or a 2nd embodiment. As described above, the heat radiation amount adding means 12 calculates the heat radiation amount from the side surface of the flat plate 1 with reference to the temperature of the side sensor 10, and supplies the side heater 3 with the heat amount equal to the heat radiation amount via the heater output means 14. Let me. Here, the heat release amount ΔQ from the side surface of the flat plate is α, the heat transfer coefficient from the flat plate side surface to the outside air is α, the area of the side surface is S, and the temperature difference between the flat plate side portion and the outside air is ΔT, ΔQ = α × S × ΔT ····························································································· | The amount of heat calculated from the equation is the amount of heat released from the side surface, and is the amount of heat input by the heater output means 14. It should be noted that a constant value may be used as the outside air temperature in advance, or the temperature of the outside air may be measured in real time and used as the outside air temperature data. FIG. 5 does not show means for measuring the outside air temperature.

FIG. 6 is a diagram for more specifically explaining the heating device according to this embodiment, and is a diagram of the flat plate 1 viewed from the side. The heat radiation amount adding means 12a and 12b use the temperature and the expression of the side sensors 10a and 10b respectively,
The amount of heat released from the side surface, that is, the amount of heat input by the side heater is determined. Since the side heater supplements the heat radiation from the side surface, the heating of the side heater and the heat radiation from the side surface cancel each other, so that the inflow and outflow of the heat from the side surface become apparent. Therefore, since the main heaters perform the same output, that is, each of the main heaters 2a to 2d applies the same amount of heat to the flat plate 1 and radiates heat only from the upper and lower surfaces of the flat plate 1, the temperature distribution in the flat surface is small. Become. Actually, a temperature distribution occurs between the heaters when the thermal conductivity of the flat plate is poor, but the temperature distribution is smaller than the temperature distribution caused by heat radiation from the side surface. Further, the problem of the temperature distribution between the heaters can be easily solved by narrowing the interval between the heaters or increasing the thermal conductivity of the flat plate.

When it is desired to make the temperature of the flat plate uniform, the temperature of the main heater and the temperature of the side heater are finally equalized. Therefore, the temperature of the main sensor is used instead of the temperature of the side sensor. The calorific value may be obtained. Also in this case, the temperature of the flat plate converges, and the temperature distribution becomes small.

With the above configuration, the temperature difference between the flat plates of the heating device can be suppressed to within 10 ° C. around 400 ° C. and within 5 ° C. for the aluminum alloy flat plate. Could be kept within ± 10 μm. In addition, since a simple arithmetic function can be provided without using a complicated controller for performing PID control or the like for the heat radiation amount adding means, there are effects such as simplification of the apparatus and cost reduction.

The other effects are the same as those of the first or second embodiment.

(Fourth Embodiment) FIG. 7 shows a fourth embodiment of the present invention.
It is a figure explaining a heating device by an embodiment, and shows a portion, such as a side heater of a flat plate, a radiation amount addition means, and a side sensor, in a 1st embodiment or a 2nd embodiment.

In this embodiment, as shown in FIG. 7, a reference sensor 25 is provided at the center of the flat plate at a distance L from the side sensor 10. The heat radiation amount adding means 12 refers to the temperature of the side sensor 10 and the temperature of the reference sensor 25, and
The amount of heat radiation from the side surface is calculated, and the side heater 3 is supplied with the amount of heat equal to the amount of heat radiation via the heater output means 14. Here, the amount of heat radiation ΔQ from the side surface of the flat plate is equal to the amount of heat flowing from the center of the flat plate to the outer periphery in the flat plate. The amount of heat is λ for the thermal conductivity of the flat plate, S for the side surface area, If the distance and the temperature difference between the sensor and the reference sensor 25 are L and ΔT, respectively, it can be approximated as ΔQ = λ × S × ΔT / L... Using the conductivity λ, the side area S, the distance L, and the temperature difference ΔT obtained from the side sensor and the reference sensor, the amount of heat calculated from the equation is used as the amount of heat radiated from the side surface, and the amount of heat input by the heater output means 14. I have. Here, the expression is an approximate expression. That is, it is a part of the side surface of the area S that measures the temperature at the two points of the sensors 10 and 25, and the area S
The temperature difference may be different in other parts of the side. As described above, in all parts of the side surface, the temperature difference between the lengths L perpendicular to the side surface is the temperature difference Δ obtained from the sensors 10 and 25.
Since it is not the same as T, the obtained ΔQ may be larger than the actual heat release amount in some cases. However, it did not significantly affect the temperature distribution.

The reference sensor 25 can be a main sensor. FIG. 7 does not show the main sensor.

With the above configuration, the temperature difference between the flat plates of the heating device can be suppressed to within 10 ° C. around 400 ° C. and within 5 ° C. for the aluminum alloy flat plate. Could be kept within ± 10 μm.

The other effects are similar to those of the third embodiment.

(Fifth Embodiment) FIG. 8 is a view for explaining a heating apparatus according to a fourth embodiment of the present invention. It shows a portion such as a calorie adding means and a side sensor. In this embodiment, the heat radiation amount adding means 12 refers to the temperature of the side sensor 10 and the temperature of the main sensor 4 so that the temperature of the side sensor 10 is equal to the temperature of the main sensor 4 from the side of the flat plate 1. The amount of heat equal to the amount of heat released is supplied from the side heater 3. Side sensor 10
When there is a temperature difference between the sensor and the main sensor 4, heat flows in a direction from the center to the side surface in the flat plate, and part of the heat generated from the main heater is released from the side surface. Therefore, when the temperature difference is eliminated and the heat flow in the flat plate is stopped, the heat generated from the main heater is not released from the side surface. At this time, the amount of heat supplied to the side heater 3 is equal to the amount of heat radiated from the side,
The heat from the heater and the heat radiation from the side are offset, and the heat from the side part is apparently eliminated.

With the above configuration, the temperature difference between the flat plates of the heating device can be suppressed to within 10 ° C. around 400 ° C. and within 5 ° C. for the aluminum alloy flat plate. Could be kept within ± 10 μm.

The other effects are similar to those of the first embodiment or the second embodiment.

[0058]

According to the first aspect of the present invention, the side heater for heating the vicinity of the side surface or the outer peripheral portion of the flat plate inputs heat so as to compensate for the heat radiation from the side surface of the flat plate. This has the effect of reducing the temperature distribution.

According to the second aspect of the present invention, the arrangement of the side heaters on the four sides of the rectangular flat plate has the effect of reducing the number of controllers and reducing the temperature distribution. . Furthermore, by using a cartridge heater as a heater, a simple configuration heating device can be manufactured, and there are effects such as simplification of the heating device and cost reduction of processing and assembly.

According to the third aspect of the present invention, the output of the side heater is equivalent to the amount of heat released from the side surface (heat transfer coefficient).
By setting the heat amount to x (side surface area) x (temperature difference between the temperature of the flat plate side portion and the outside air temperature), the number of controllers is reduced and the temperature distribution of the flat plate is reduced as compared with the related art. In particular, it is only necessary to provide a simple arithmetic function without using a complicated controller for performing PID control or the like as the heat radiation amount adding means, so that there are effects such as simplification of the apparatus and cost reduction.

Further, according to the fourth aspect of the present invention, the number of controllers can be reduced by obtaining the flow of heat toward the side surface from the temperature difference between at least two sensors and compensating for the amount of heat radiation from the side surface. This has the effect of reducing the temperature distribution of the flat plate. In addition, the heat radiation amount adding means only needs to have a simple calculation function, and has effects such as simplification of the apparatus and cost reduction.

Further, according to the fifth aspect of the present invention, the number of controllers is reduced by compensating for the amount of heat radiated from the side surface by making the temperature of the side sensor equal to the temperature of the main sensor, thereby reducing the number of controllers. This has the effect of reducing the temperature distribution of the flat plate.

By using the heating device having the above-described structure, for example, when heating glass, the temperature distribution is reduced, and the thermal deformation of the glass is reduced. As a result, when processing, assembling, or forming an element on glass at a high temperature, errors in the position are reduced due to less deformation of the glass, and good processed and assembled products with high accuracy are obtained. Or a formed product could be supplied.

In particular, when pixels are formed on the glass used for display, the glass expands uniformly, and if the pixels are formed uniformly according to the deformation, the glass and the pixels on the glass are uniform even after the temperature drops. As a result, non-uniform thermal expansion and deterioration of image quality due to thermal contraction could be prevented. Also, when combining a plurality of glasses with high accuracy, the thermal deformation of each glass can be reduced, so that the positional accuracy between the glasses can be improved.
With such a configuration, the temperature difference between the flat plates of the heating device is reduced by 40
The temperature could be kept within 10 ° C. around 0 ° C., and the accuracy of the heated glass was also within ± 10 μm. In particular, when an aluminum alloy flat plate was used, the temperature difference could be suppressed to around 400 ° C. and within 5 ° C.

As described above, since not only the temperature of the flat plate of the heating device and the temperature of the object to be heated become uniform, but also the thermal deformation of the object to be heated can be minimized, the processed product having good positional accuracy can be obtained. , Assemblies and formed products.

Although the number of controllers varies depending on the configuration, the number of controllers can be reduced to about 1/5 to 1/10 or less, and the temperature distribution can be reduced. Therefore, the apparatus is simplified and the controller is not used. Costs were significantly reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a heating device according to a first embodiment of the present invention.

FIG. 2 is a view showing a heating device according to a second embodiment of the present invention.

FIG. 3 is a heater layout diagram in a flat plate surface for clarifying the positional relationship of the cartridge heater of FIG. 2;

FIG. 4 is a view showing a modification of the heating device of the embodiment shown in FIG. 2;

FIG. 5 is a diagram for explaining a heating device according to a third embodiment of the present invention.

FIG. 6 is a diagram for more specifically explaining the heating device according to the embodiment shown in FIG. 5;

FIG. 7 is a view for explaining a heating device according to a fourth embodiment of the present invention.

FIG. 8 is a view for explaining a heating device according to a fifth embodiment of the present invention.

FIG. 9 is a diagram showing a conventional heating device using a cartridge heater.

FIG. 10 is a diagram showing a conventional heating device using a heater block.

[Explanation of symbols]

 Reference Signs List 1 flat plate 2 main heater 3, 3a to 3d side heater 4 main sensor 5, 11, 11a to 11d temperature signal 6 control means 7 control signal 8, 14, 14a to 14d heater output means 9, 15, 15a to 15d physical quantity 10 , 10a to 10d Side sensor 12, 12a to 12d Heat release amount adding means 13, 13a to 13d Heat quantity signal 25 Reference sensor

Claims (5)

[Claims] 1. A heating device for heating a flat plate, comprising: a side heater for heating a side surface or an outer peripheral portion of the flat plate; a main heater located at a central portion of the flat plate; and an output of the main heater. And a heat radiation amount adding means for making the output of the side heater equal to the heat radiation amount from the side surface of the flat plate. 2. The flat plate has a rectangular shape, one or more cartridge heaters are inserted into the center of the flat plate as the main heater, and another cartridge heater is a four-sided portion of the rectangular flat plate as the side heater. The heating device according to claim 1, wherein the heating device is inserted into each of the heating devices. 3. The heat radiation amount further comprises: at least one main sensor disposed in an area of the flat plate where the main heater exists; and at least one side sensor disposed in a portion of the side heater. The adding means calculates the output of the side heater from the amount of heat radiation from the side surface of the flat plate (heat transfer coefficient from the side surface of the flat plate to the outside air) × (area of the side surface) × (temperature difference between the flat plate side portion and the outside air). The heating device according to claim 1, wherein the heating amount is set to a predetermined value. 4. The apparatus according to claim 1, further comprising: at least one main sensor disposed in an area of the flat plate where the main heater exists; and at least one side sensor disposed in a portion of the side heater. The adding unit predicts a heat release amount from the side surface from a heat flow toward the side surface calculated from the temperature of the side sensor and the temperature of the main sensor, and supplements the heat release amount with an output of the side heater. The heating device according to claim 1, wherein: 5. The apparatus according to claim 1, further comprising: at least one main sensor disposed in an area of the flat plate where the main heater exists; and at least one side sensor disposed in a part of the side heater. 3. The heating device according to claim 1, wherein the adding unit compensates a heat radiation amount from a side surface by setting a temperature of the side sensor to be equal to a temperature of the main sensor. 4.