KR100346360B1 - Thermal treatment unit for heating plate type work under windless condition of one surface - Google Patents

Abstract

(Problem) Heat treatment of large workpiece is possible with good heat treatment quality.

(Solution means) In the main body 1, there is a wind tunnel 4 formed through the heat treatment chamber 2 of the work W, the heat storage plate 3, a heating heater 5 which is turned on at the time of temperature increase, and a normal hot air circulation system. It is installed. The heat treatment chamber 2 includes an air volume adjusting plate 21 and a porous plate 22 at the inlet and the outlet, while the wind tunnel 4 has a smaller opening area than the wind tunnel inlet 41 and the porous plate 22. (42) is provided. The heat storage plate 3 has a plurality of vent holes 31.

(Effect) In large workpiece | work, the air volume control plate is closed, and the hot air which flowed in from the wind tunnel is made to contact the lower surface of a workpiece | work through a ventilation hole, and is discharged from the porous plate 22. The upper surface of the work becomes unwinded and can be fired with high quality. In the lower surface, heat exchange performance is improved by turbulence. The work can be heated to a good temperature distribution by the heat storage air from the heat storage plate and the plurality of vents. The temperature increase rate is increased by the temperature increase heater, so the heat treatment efficiency is good.

Description

Heat treatment device that can heat one side of flat work without wind {THERMAL TREATMENT UNIT FOR HEATING PLATE TYPE WORK UNDER WINDLESS CONDITION OF ONE SURFACE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment apparatus for heat-treating flat articles, and is particularly effective for heat treatment apparatuses used in production facilities such as LCD (liquid crystal display) glass substrates.

As a heat treatment apparatus for an LCD glass substrate or the like, an air circulation heating apparatus (for example, see Japanese Patent Laid-Open No. 6-317514) is used. In this apparatus, the glass plate was heated by flowing hot air controlled at a predetermined temperature in one direction along the glass surface in parallel with this. For this reason, the temperature rise of a glass plate is fast in wind and slows in wind, and the difference of temperature distribution which generate | occur | produces in a glass plate gives a difference in plastic quality. In this case, if the glass plate was of the usual size as in the prior art, the temperature difference between the glass plate between the wind-up side and the wind-down side was also relatively small, and the variation in the plastic quality was within an acceptable range.

Recently, however, due to the large screen and cost down of the liquid crystal display, in order to enable the acquisition of a large number of screens at one time, there is a tendency to enlarge the mother glass, and the technical development of the large mother glass such as exceeding 1 meter angle is also in progress. have. In this way, when the large glass plate exceeding 1 meter angle is fired, even if the wind up side reaches a predetermined temperature to be heated and heat-treated, there is a large temperature increase delay of 10 ° C. lower than the predetermined temperature on the down wind side, resulting in a high quality of plastic. The deviation will exceed the allowable limit. Moreover, when performing high quality heat processing, there exists a baking process which cannot use the hot air with a high flow velocity in terms of the influence on the surface state of glass.

In such a glass firing process, a hot plate heating apparatus (for example, see Japanese Patent Laid-Open No. 6-97269) is usually used. The hot plate is formed by closely adhering a plurality of heat generating elements to the back surface of a metal plate having a high thermal conductivity processed to a high flatness on the surface, so that a uniform surface temperature is obtained by finely adjusting the calorific value of each heat generating element.

However, such a hot plate is extremely expensive, and in a hot plate having an area corresponding to a mother glass such as exceeding a 1 meter angle, it is difficult to crack in terms of surface processing accuracy and the like, and high precision is achieved. The temperature distribution could not be achieved. In addition, in order to increase the heating efficiency and to facilitate temperature management of the mother glass itself, it is preferable to contact the glass and the hot plate, but in order to suppress the peeling charge occurring in the mother glass when the two are separated. These are made into a non-contact state with a slight gap of about 0.2 mm. However, when the mother glass is made large, even if the planar accuracy itself is good, due to thermal expansion deformation of the glass and hot plate, self-deflection of the glass, etc., the gap is not maintained with high precision, and peeling charging cannot be prevented.

This invention solves the said problem in the prior art, and makes it a subject to provide the heat processing apparatus which can heat-process even a large article with good heat processing quality.

1 is an explanatory diagram showing an example of a heat treatment apparatus to which the present invention is applied;

2 is an explanatory diagram showing an arrangement relationship between a heat storage plate and a work of the apparatus.

"Description of Symbols for Major Parts of Drawings"

2: heat treatment chamber 3: heat storage plate (partition member)

4: Wind tunnel (parallel space) 5: Temperature heating heater (heating means)

21: Air volume adjusting plate (opening and closing plate) 22: Perforated plate (outlet opening)

31: Ventilation hole (plural conductive parts) 41: Wind tunnel inlet (one side opening)

42: porous plate (the other side resistance plate) W: work (flat plate-shaped article)

The present invention, in order to solve the above problems, the invention of claim 1, in the heat treatment apparatus for heat-treating a heated article by circulating a heated gas,

A heat treatment chamber for heat-treating the article, the heat treatment chamber having one end section open and an opening and closing plate for opening and closing the article, and having an outlet opening at the other end section, and parallel to the bottom of the heat treatment chamber through a partition member. A parallel space having a one side opening at a position corresponding to the one end cross section and a second resistance plate having a smaller opening area than the outlet opening as the other side resistance plate at a position corresponding to the one end cross section; And a plurality of conductive portions provided in the partition member so as to conduct the parallel space and the heat treatment chamber.

In addition to the above, the invention of claim 2 is characterized in that a heating means is provided on the parallel space side of the conductive portion.

In addition to the features of the invention of claim 1, the invention of claim 3 is characterized in that the partition member is a heat storage plate having a large heat capacity.

(Example)

1 shows an example of the overall configuration of a heat treatment apparatus to which the present invention is applied.

The heat treatment apparatus is a device that circulates hot air, which is heated gas, to heat the work W, such as an LCD glass substrate, which is a flat article, and is formed in the main body 1 that forms a container shape surrounded by the heat insulating wall 1a. A temperature increaser for use in heating up the work chamber as a heating means provided therein, in a heat treatment chamber 2 for heat-treating (W), a wind tunnel 4 in parallel space formed in parallel through a heat storage plate 3 as a partition member below. Hot air 5 is provided.

In the main body 1, the main heater 6, the blower 7, the blower duct 8, high performance as the path which the hot air shown by the arrow flows as a part which circulates a hot air similarly to a normal heat processing apparatus. It consists of the filter 9, the plenum chamber 10, the said heat processing chamber 2, the wind tunnel 4, the intake duct 11, etc., and heat-processes the workpiece | work W about 230 degreeC, for example, with air. It circulates by heating to temperature. Further, the heat treatment chamber 2 may have only one stage, but in this embodiment, six stages are arranged in parallel in the vertical direction in order to increase processing efficiency.

In addition, although not shown, a heat insulating door is provided immediately in front of the ground, which is the front part of the main body 1, and the opening and the opening for entering and exiting the workpiece are opened and closed at a position corresponding to the work W at each end thereof. Moving doors for each stage are installed. Although not shown, the workpiece | work W is protruded from the heat storage plate 3, etc., and is supported by a suitable height position. Moreover, the operation control panel which performs the operation and control of all the apparatuses is also installed in a suitable position. Temperature control of the main heater 6 and the temperature riser 5 is also performed by this operation control panel.

The heat treatment chamber 2 is provided with an air volume adjusting plate 21, which is an opening and closing plate having one side end face open and opening and closing, and a porous plate 22 forming an outlet opening at the other end face. The air volume adjusting plate 21 can open and close the opening from fully developed to fully closed. The porous plate 22 is a plate having a small air passage resistance having a large opening ratio such that reverse flow of turbulent air from the intake duct 11 side can be prevented.

The wind tunnel 4 includes a wind tunnel inlet 41 as one side opening and a porous plate 42 of the wind tunnel outlet as the other side resistance plate at positions corresponding to one side and the other end surface of the heat treatment chamber 2, respectively. have. The opening area of the porous plate 42 is considerably smaller than that of the porous plate 22. As described above, the heat treatment chamber 2 and the wind tunnel 4 formed in six stages are partitioned by the partition plate 12 together with the heat storage plate 3, and each is a space part arranged in parallel with each other.

The heat storage plate 3 is made of a plate having a large heat capacity such as a metal having a suitable thickness, such as stainless steel, for example, and includes a plurality of vent holes 31 as a plurality of conductive portions. The vent hole 31 is perforated through a suitable arrangement such as a checkerboard eye shape or a zigzag shape on the entire surface of the heat storage plate 3 in a suitable shape such as a round hole, an angular hole, or a long hole. In addition, although not shown, grooves are formed in a lattice shape on the heat treatment chamber 2 side of the heat storage plate 3 to enlarge the surface area, to turbulence the hot air flowing through the surface, and to improve the heat exchange rate. have. The heat storage plate 3 may be disposed in parallel with the wind tunnel 4 as shown in FIG. 1, but it is preferable to incline and arrange the heat storage plate 3 as shown in FIG. 2 to widen the distance from the work W at the downstream side. . In this way, even if the flow rate of hot air accumulates and increases in the flow direction, the flow velocity does not become excessive and the hot air easily passes through the lower surface of the work W. FIG.

The temperature rising heater 5 is provided in the inlet part of the ventilation hole 31 of the heat storage plate 3 in the wind tunnel 4. This heater is small enough to raise the temperature of the part which enters the ventilation hole 31 during the hot wind which is heated and circulated by the main heater 6 at the time of raising the work temperature, by several degrees Celsius. Then, the control device (not shown) turns on / off at a predetermined timing.

The heat treatment apparatus as described above is operated as follows.

In the normal operation state in which the workpieces W enter all the heat treatment chambers 2 of six stages and reach a temperature of, for example, about 230 ° C., the heater 6 and the blower of the hot air circulation system ( 7) is operated and hot air is circulated inside the main body 1. The temperature rising heater 5 is turned off. The work W is supported on the heat storage plate 3 at an appropriate interval therefrom. And the wind volume adjustment plate 21 is fully closed at the time of no wind operation which heat-processes the workpiece which needs to perform high quality baking by large size mother glass or no wind.

In the normal state in such a windless operation, hot air enters the wind tunnel 4, but the opening area of the porous plate 42 at the exit is considerably larger than the opening area of the porous plate 22 at the outlet of the heat treatment chamber 2. Since it is small, the hot air which entered the wind tunnel 4 cannot pass through this part by the resistance of the porous plate 42, and the pressure in the wind tunnel 4 becomes high. On the other hand, since the air volume adjusting plate 21 is fully closed, the pressure in the heat treatment chamber 2 is lowered. As a result, hot air flows into the heat treatment chamber 2 from the wind tunnel 4 through the vent hole 31 of the heat storage plate 3. The amount of inflow of such hot air is determined so that the opening area of the porous plates 22 and 44 is appropriately set to be an appropriate amount in the actual apparatus.

In this state, when a workpiece | work is heat-processed and the workpiece | work in the heat processing chamber of any one stage passes a predetermined heat processing time, the workpiece is taken out and a new workpiece is carried in instead. The carrying out of the work is carried out by a robot hand or the like installed in an external work transport system. The workpiece after the firing process is transferred to the next process. Moreover, since the periphery of each heat processing chamber 2 formed in multiple stages in the main body 1 is closed, the entry | entrance of the workpiece | work of either stage does not disturb the temperature of another stage.

Even when a new work is brought into the heat treatment chamber 2, the hot air is circulated in the same manner as in the normal state, and the air volume adjusting plate 21 is in a fully closed state. Therefore, the hot air passes through the air vent 31 and flows from the high pressure wind tunnel 4 into the low pressure heat treatment chamber 2. After this hot air collides with the back surface of the workpiece | work W, most of it flows in the exit direction from the back surface side of the workpiece | work W. As shown in FIG. At this time, the hot air introduced from the plurality of vent holes 31 collides with the back surface side of the workpiece W, collides with the already flowing hot air, mixes, or is formed by a lattice-shaped groove formed on the surface of the heat storage plate 3. It becomes turbulent and becomes the medium of extremely efficient heat exchange between the workpiece | work W and the heat storage plate 3.

In this case, since the temperature of the newly introduced work is low, the hot air heats the work and the temperature decreases. However, the work is heated while absorbing heat from the heat storage plate 3 and recovering the temperature due to the turbulence effect. Since the heat storage plate 3 is heated by circulating hot air, and has a uniform temperature distribution, and its heat capacity is sufficiently large, it is possible to heat the hot air at almost the same temperature and heat the workpiece through the hot air. Even if given, the temperature decrease is slight. Moreover, in the flow direction of the hot wind along a workpiece | work, the hot air of substantially the same temperature which passed through the ventilation hole 31 is supplied sequentially. As a result, even a low temperature workpiece is heated uniformly in the flow direction of hot air, and is heated up while maintaining a nearly uniform temperature distribution. In addition, the workpiece is rapidly heated by the turbulence effect.

Furthermore, in this example, the temperature increase heater 5 is provided, it is turned on in conjunction with the work carrying in, and the hot air passing through the air vent 31 is heated by several degrees Celsius. As a result, the temperature difference between a hot air and a workpiece | work becomes large, and the temperature increase rate of a workpiece | work can be made quick. In particular, when the temperature of the workpiece approaches the heat treatment temperature, the temperature difference with the hot wind approaches, and the heat exchange amount greatly decreases, and the temperature increase time becomes significantly long. However, when the hot air is reheated as in the present example, A certain temperature difference can be secured, and the temperature increase time, and thus the heat treatment time, can be shortened to increase the processing efficiency.

When the workpiece reaches the heat treatment temperature, the elevated temperature heater 5 is turned off. Furthermore, since the temperature at which the work is to be heat treated has a certain allowable width, it is preferable that the elevated temperature heater 5 be turned off at a lower temperature among the heat treatment temperatures. Thereafter, the workpiece is adjusted to and maintained at a heat treatment temperature by hot air circulated. At this time, since the work has reached the heat treatment temperature, there is almost no endotherm of the work itself, and the heat dissipation loss of the circulating hot air from the main body 1 to the outside is compensated by the main heater 6, and the hot air is maintained at a constant temperature. . As a result, the temperature distribution of the workpiece becomes even better at such temperature holding.

After the heat treatment of the work of the heat treatment chamber in one stage is completed, when the heat treatment time of the work of the other stage and another stage subsequently passes, the work is carried in and out of each stage as well. Therefore, when the heat treatment chamber is provided in multiple stages as in the present example, heat treatment efficiency is improved because heat treatment of the workpiece is completed in a short time interval.

Even if the air volume adjusting plate 21 is completely closed as described above, the workpiece can be heat treated by blowing hot air from the lower surface side of the workpiece. And since the slight hot air which flowed through the both ends from the lower surface side of a workpiece only flows to the upper surface side of a workpiece | work, the upper surface side of a workpiece | work will be in a state near windless. In addition, since the heat treatment chamber 2 itself is under a hot air atmosphere circulating in the main body 1, there is no heat dissipation from the upper surface of the work like simple hot plate heating. As a result, heat processing with high plastic quality close to a non-wind is attained, and the workpiece can be heat treated satisfactorily without flowing hot air directly.

In addition, since the workpiece is heated mainly from the lower surface of the workpiece through hot air, and the workpiece upper surface is also in a hot air atmosphere as described above, the workpiece is disposed at a proper interval with respect to the heat storage plate 3, so that the workpiece is spaced therebetween like hot plate heating. You can't get close to a smile. As a result, even if the workpiece is a large size, it is possible to reliably prevent the charge breakdown of a circuit formed on the surface of the workpiece.

When the workpiece is of a normal size and passage of hot air to the surface side is allowed, the hot air flow is directly introduced into the heat treatment chamber 2 with the airflow rate adjusting plate 21 at an appropriate opening degree. Even in that case, since the opening area of the porous plate 42 is smaller than that of the porous plate 22, the hot air in the wind tunnel 4 also flows from the air vent 31 into the heat treatment chamber 2, thereby allowing the work of the work. The back side is also heated. As a result, the work is quickly and uniformly heated up, the temperature distribution is good, and the heat treatment time is further shortened.

As described above, according to the present invention, in the invention of claim 1, the heat treatment chamber for heat-treating the flat-shaped article has an opening at one side of the cross section and has an opening / closing plate which can open and close the outlet. Since the opening and closing plate is operated, the inside of the heat treatment chamber can be made into either an airless state or an ordinary heating gas blowing state. As a result, in the large article or the article which needs high quality baking, the inside of the heat treatment chamber can be made into a windless state by closing the opening and closing plate. On the other hand, in another common article, the open / close board can be opened to introduce a heating gas into the heat treatment chamber, and the temperature rise time of the article can be shortened and heat treated. That is, such a selection is made possible by the opening and closing plate. Moreover, it is easy to keep the opening and closing plate at a suitable opening position, and if this is done, a moderate breeze can be flowed into the heat treatment chamber, and depending on the article, such a blowing may be good.

Subsequently, a parallel space is provided below the heat treatment chamber through a partition member, one side opening is provided at a position corresponding to one end face of the heat treatment chamber, and the outlet of the heat treatment chamber is located at a position corresponding to the other end face. Since the other side resistance plate having a smaller opening area than the opening is provided, and a plurality of conductive parts are provided in the partition member, when the opening / closing plate of the heat treatment chamber is closed, heated gas enters from one side opening of the parallel space, which is a partition. A gas flow can be formed to enter the heat treatment chamber through the plurality of conducting portions of the member and to exit from the opening of the heat treatment chamber. At this time, since the opening and closing plate is closed, the upper surface side of the article is maintained in a state close to windless.

Since the heat-treatment chamber contains a plate-like article for heat treatment, the gas flows through the plurality of conducting portions so as to contact the lower surface side of the article and flow along it, leaving the upper surface side of the article almost unattended. , The article can be heated from the lower side. As a result, in a firing process in which a heating gas having a high flow rate cannot be brought into contact with the surface of an article as a firing surface, the upper surface side is fired from the lower surface side of the article, and heat treatment with high plasticity quality not affected by the flow rate of the heating gas can be performed. have.

In this case, since the heating gas collides with the article because it passes through the conduction portion of the partition member, and flows in from the plurality of conducting members, the heating gases introduced from the lower surface side of the article collide and mix with each other, so that the flow of the heating gas is turbulent. And the heat exchange efficiency is improved. As a result, the temperature of the article can be raised quickly. In addition, since the heating gas can be uniformly supplied by the plurality of conducting portions, a large temperature difference does not occur in the heating gas on the upstream side and the downstream side of the article as in the prior art, and the temperature distribution of the article at the time of temperature increase can be improved. have.

In the invention of claim 2, in addition to the above, since heating means is provided on the parallel space side of the conducting portion, the temperature of the circulating heating gas can be raised to allow the conducting portion to pass. As a result, when the temperature approaches the temperature at which the article is to be heat treated, a certain temperature difference can be secured between the article and the heating gas, and the temperature increase rate of the article can be increased to increase the heat treatment efficiency.

In the invention of claim 3, in addition to the invention of claim 1, since the partition member is a heat storage plate having a large heat capacity, even if the heating gas transfers heat from the heat storage plate to the article, the temperature of the heat storage plate hardly decreases. As a result, even when the temperature of the article is raised, the article is uniformly heated, and the temperature distribution can be further improved.

In this case, the heat-treatment chamber into which the article enters is in an atmosphere of a heating gas which is circulated as a whole, and at the lower side of the article, heat exchange between the heat storage plate and the article is carried out through the heating gas, so that the article has a proper distance from the heat storage plate. It is good to be arranged. Therefore, there is no need to approach the article and the heat storage plate as in the conventional hot plate heating, and even a large sized article can solve the problem of peeling charging and heat treatment safely.

Claims (3)

A heat treatment apparatus for circulating a heated gas to heat-treat a flat article W, As a heat treatment chamber 2 for heat-treating the article W, one end surface is opened and an opening and closing plate 21 capable of opening and closing the article W is provided, and a heat treatment is provided with an outlet opening 22 in the other end surface. It is formed in parallel through the partition member 3 below the chamber 2 and the heat treatment chamber 2, and is located in a position corresponding to the one side opening 41 and the other end surface at a position corresponding to the one end surface. A parallel space 4 having the other resistance plate 42 having an opening area smaller than that of the outlet opening 22 as the other resistance plate 42, the parallel space 4, and the heat treatment chamber 2 are provided. And a plurality of conductive portions (31) provided in said partition member (3) so as to conduct. The heat treatment apparatus according to claim 1, wherein a heating means (5) is provided on the side of said parallel space of said soil tube portion (31). The heat sink according to claim 1, wherein the partition member (3) is a heat storage plate having a large heat capacity such that the temperature decrease is small even if the heat is continuously heated to a constant temperature to impart heat to the work W through the hot air. Heat treatment device.