JP4549798B2 - Mold press molding apparatus and optical element manufacturing method - Google Patents

Description

  The present invention relates to a mold press molding apparatus for producing a molded body such as an optical element by press molding a molding material such as glass with a precision processed mold, and a method for producing an optical element using the mold press molding apparatus. In particular, the present invention relates to a mold press molding apparatus including a plurality of processing chambers requiring temperature control, such as a heating chamber, a press chamber, and a cooling chamber, and an optical element manufacturing method.

Various methods have been developed for press molding optical elements such as high-precision glass lenses using a precision-processed mold without fusing softened glass (see, for example, Patent Document 1).
Patent document 1 is a structure which manufactures a shaping | molding raw material (for example, glass preform) to a glass molded object by sequentially transferring a shaping | molding die in process chambers, such as a heating chamber, a press chamber, and a cooling chamber, which are arranged side by side. It has become. According to the apparatus having such a configuration, it is said that the heat uniformity of the mold can be maintained and the molded body can be continuously manufactured at a high processing speed.
Japanese Patent Laid-Open No. 1-157425

Usually, the press by the mold press molding apparatus is performed at a high temperature. In particular, when the molding material is a glass material, the pressing temperature is about 500 to 800 ° C. Under such high temperatures, mold materials (ceramics, carbides, metals, etc.) and release films (those containing carbon as the main component, those containing precious metals as the main component) applied to the molding surface are protected. Therefore, the press atmosphere needs to be non-oxidizing.
Accordingly, a processing chamber that is at a high temperature, such as a press chamber in which press molding is performed, is evacuated to a vacuum, or a non-oxidizing gas atmosphere such as nitrogen or argon. Further, in order to maintain the atmosphere in the processing chamber, it is necessary to take out and take in the mold while preventing the gas from flowing outside.

Here, the configuration of the apparatus disclosed in Patent Document 1 will be described with reference to FIGS.
This apparatus includes a carry-in / out chamber P1 disposed in the upper part of the chamber 1 and a number of processing chambers (first heating chamber P2, second heating chamber P3, soaking chamber P4) arranged in the chamber 1 in the circumferential direction. , Press chamber P5, first annealing chamber P6, second annealing chamber P7, and quenching chamber P8). The inside of the chamber 1, that is, the processing chambers P <b> 2 to P <b> 8 is always in a non-oxidizing gas atmosphere, and a mold 4 containing a molding material (glass to be molded) is placed on the support 3 of the turntable 2. The process chambers P2 to P8 are sequentially transferred. As shown in the figure, the processing chambers P2 to P8 are partitioned by shutters S1 to S6 (not provided between the soaking chamber P4 and the press chamber P5).

  The rotary table 2 includes a rotary shaft and an index machine (not shown) at the center. In the support base 3, the lower protrusion 3 a of the base portion is engaged with an attachment hole 2 a formed in the outer peripheral portion of the turntable 2. A molding die 4 that accommodates the glass to be molded is placed on the support 3. The support table 3 is arranged so that the molding die 4 passes through substantially the center of each of the processing chambers P <b> 2 to P <b> 8 in the chamber 1.

As shown in FIG. 2, the first heating chamber (P2) 5 that is one of the processing chambers is formed in a case shape by an outer surface member 51, an inner surface member 52, an upper surface member 53, and a bottom surface member 54. Further, inside the first heating chamber 5, a resistance heating element 6 and a reflector (reflector) 7 as heating means are arranged on both sides in the mold transfer direction. The bottom member 54 is formed with a slit 55 extending in the circumferential direction.
Note that the processing chambers (other heating chambers, press chambers, cooling chambers, etc.) other than the first heating chamber P2 have substantially the same structure as the first heating chamber P2 except that the room temperature is mainly different.

  Thus, in the conventional rotary mold press molding apparatus, the slit through which the support is passed is formed on the bottom surface member instead of the inner side surface member of the case. For this reason, a heater can be arrange | positioned to the whole inner surface of the inner surface member of a case, and also the calorie | heat amount escaped from a slit can be decreased. Thus, it is described that the temperature distribution in the processing chamber can be made uniform to some extent, and as a result, a molded body with high shape accuracy can be obtained.

Thus, the technique described in Patent Document 1 can be said to be an effective means in that the effect of making the temperature distribution in the processing chamber uniform can be obtained. However, it has been obtained by solving the conventional problems such as limitation of the heater installation range and leakage of heat. For this reason, it is impossible to obtain the uniformity of the temperature distribution required for realizing the improvement in surface accuracy and shape accuracy strictly required for today's optical elements.
Therefore, the inventor conducted independent research on how to perform precise and strict temperature control in order to make the temperature distribution in the processing chamber more uniform. As a result, as a new challenge in making the temperature distribution in the processing chamber even more uniform, it is essential to prevent temperature differences due to parts in the processing chamber and to prevent temperature fluctuations over time. Reached.

In the mold press molding apparatus, it is inevitable that a temperature difference occurs in the vertical direction due to convection in the atmosphere in the processing chamber (usually using non-oxidizing N ₂ or the like). This is a temperature difference between the upper and lower molds, and also causes temperature non-uniformity inside the contained molding material (for example, glass preform), thereby deteriorating surface accuracy.
Further, in the mold press molding apparatus, the processing chambers in which the molds are sequentially transferred are independently controlled to temperature settings suitable for the respective processing. There is a temperature difference of about 10 ° C to 200 ° C. For this reason, it is inevitable that a temperature gradient is generated in the direction of travel of the mold due to heat conduction of the constituent members of the processing chamber and mixing of atmospheric gas during transfer.
Furthermore, as shown in FIG. 2, in the first heating chamber P <b> 2, the support base 3 is disposed on the lower side, the mold 4 is disposed in the center, and the upper side is a space region. The temperature in the room, particularly in the vertical direction, varies depending on the material (thermal conductivity) of the mold 4 and the presence or absence of an object. Thus, when a temperature gradient in the transfer direction of the mold or a temperature difference in the vertical direction in the processing chamber occurs, it becomes difficult to stably produce a molded product with uniform quality.

In the mold press molding apparatus having the above-described configuration, production is performed with a substantial molding cycle time that is a fraction (depending on the number of processing chambers) of the time required for a thermal cycle of one mold. Therefore, it is advantageous in mass production.
Here, in order to increase production efficiency, a case where a plurality of molding dies are simultaneously processed in one processing chamber can be considered. However, in such a case, the temperature gradient in the traveling direction has become extremely serious. This is because the temperature conditions of the plurality of molds arranged in the traveling direction are different.

  The present invention has been considered in view of the above circumstances, and prevents temperature differences due to portions in the processing chamber and temperature fluctuations over time, and realizes precise temperature management in the processing chamber, and improves the surface accuracy of the optical element. An object of the present invention is to provide a mold press molding apparatus and an optical element manufacturing method capable of further improving the shape accuracy.

In order to achieve this object, the mold press molding apparatus of the present invention includes a plurality of processing chambers including a heating chamber, a press chamber, and a cooling chamber, and a transfer for sequentially transferring a molding die containing a molding material to each of the processing chambers. A plurality of heating units provided in at least one of the processing chambers, and each of the heating units is operated based on a preset relative output. and control means for the atmosphere to a predetermined temperature, said plurality of heating units, in the interior of the processing chamber, a plurality each of the vertical direction and the transport direction of the mold, sequence and provided Rutotomoni, wherein The amount of heat given to the lower heating area near another adjacent processing chamber set at a lower temperature than the processing chamber inside the processing chamber is set at a higher temperature than the processing chamber. It has been there a structure in which set to be larger than the amount of heat applied to the upper side of the heating region of the adjacent other processing chamber close.
The relative output for each heating unit is a correlation between individual outputs, and the outputs may be relatively determined by an output ratio or an output difference, or may be a combination of individual output values.
The relative output is calculated and set so that the temperature gradient in the processing chamber can be controlled. Further, it may be obtained by a preliminary experiment. For this reason, by operating each heating unit with the relative output such as the set output ratio, the temperature gradient in the processing chamber can be controlled (relaxed and suppressed), and the temperature distribution in the processing chamber can be made uniform. Therefore, the surface accuracy and shape accuracy of the optical element can be further improved.

With such a configuration of the mold press molding apparatus, a plurality of heating units are installed in the processing chamber, and outputs capable of controlling (relaxing and suppressing) the temperature gradient in the processing chamber are set for each of the plurality of heating units. Can be operated. For this reason, the temperature distribution in the processing chamber can be made uniform, so that precise temperature control in the processing chamber can be realized, and the surface accuracy and shape accuracy of the optical element can be improved. Particularly, by providing a plurality of heating units arranged at least in the vertical direction inside the processing chamber, it is possible to control the vertical temperature gradient in the processing chamber that causes a temperature difference between the upper mold and the lower mold. Thus, the temperature difference between the upper mold and the lower mold, which has become a factor that makes it difficult to stably produce a molded product with uniform quality, can be mitigated. Preferably, it is advantageous to perform the above control in all of the heating chamber, the press chamber, and the slow cooling chamber among the processing chambers.

  Furthermore, in the mold press molding apparatus having the above-described configuration, it is conceivable that a plurality of molding dies are simultaneously processed in one processing chamber in order to increase production efficiency. In this case, the temperature gradient in the traveling direction becomes extremely serious. However, according to the present invention, the temperature distribution in the processing chamber can be made uniform, so that the temperature conditions of a plurality of molds arranged in the traveling direction are unified. . Therefore, in any mold, an optical element with very high surface accuracy and shape accuracy can be obtained.

Furthermore, the temperature gradient of the processing chamber as referred to above, along with the vertical direction in the processing chamber, arising in the transport direction of the mold. For this reason, a plurality of the heating units are provided in the processing chamber in the vertical direction and in the transfer direction of the mold, and at a lower temperature than the processing chamber in the processing chamber. The amount of heat given to the lower heating region near the other adjacent processing chamber set is higher than the amount of heat given to the upper heating region near the other adjacent processing chamber set at a higher temperature than the processing chamber. by controlling so much, the upper mold, can control the temperature gradient in the transfer direction of the temperature gradient and the mold in the vertical direction of the process chamber, such as to generate a temperature difference of the lower mold. For this reason, the temperature distribution in the processing chamber can be made uniform, and therefore the surface accuracy and shape accuracy of the optical element can be further improved.

Moreover, the mold press molding apparatus of the present invention has a configuration in which a plurality of heating units are provided in the vertical direction inside the processing chamber and a plurality are provided in the transfer direction of the molding die. Thus , the temperature gradient in the vertical direction can be controlled by a plurality of heating units provided in the vertical direction, while the temperature gradient in the transfer direction can be controlled by the plurality of heating units provided in the transfer direction of the molding die.

  There are two types of temperature gradient in the processing chamber, one due to convection of heat in the same chamber and the other due to temperature interference with the adjacent chamber. The former appears as a temperature gradient in the vertical direction in the processing chamber, and the latter appears as a temperature gradient in the transfer direction of the mold. For this reason, by providing a plurality of heating units in each of the vertical direction and the horizontal direction, both of these two types of temperature gradients can be controlled. Therefore, it is possible to prevent temperature differences due to portions in the processing chamber and temperature fluctuations with time, and it is possible to realize precise temperature management in the processing chamber, thereby further improving the surface accuracy and shape accuracy of the optical element. .

  Further, the mold press molding apparatus of the present invention includes a set temperature storage means for storing a target temperature at a predetermined position in the processing chamber provided with the heating unit as a set temperature, and a plurality of temperature measurements arranged in the processing chamber. And a comparison means for comparing the temperature measured by any one of the temperature measurement means and the set temperature output from the set temperature storage means, and the control means The plurality of heating units are operated based on the comparison result from the comparison means and the preset relative output.

When the mold press molding apparatus has such a configuration, when there is a difference between the actual temperature in the processing chamber and a set temperature that is a target value, a plurality of heating units can be operated based on a preset output. . For this reason, it is possible to immediately cope with temperature fluctuations over time and temperature differences due to parts in the processing chamber, and to minimize the temperature fluctuations.
As described above, the present invention can realize precise and strict temperature control in the processing chamber, so that the surface accuracy and shape accuracy of the optical element can be further improved as compared with the conventional case.

In the mold press molding apparatus of the present invention, for example, the temperature change in the processing chamber can be monitored by measuring the temperature in the vicinity of the heating unit. In addition, by comparing one of the measured temperatures with the set temperature and feeding back to operate the heating unit, temperature fluctuations over time in the processing chamber can be minimized.
In addition, by setting the feedback temperature to one, the temperature in the processing chamber can be controlled without being affected by the mutual interference of the plurality of heating units.

Further, the method of manufacturing an optical element of the present invention transfers a molding die containing a molding material to a plurality of processing chambers including a heating chamber, a press chamber, and a cooling chamber, and heats, presses, and cools the molding die. In a method for manufacturing a molded body including forming a molded body by performing each treatment including: a plurality of heating units are arranged in at least one of the processing chambers in a vertical direction and a transfer direction of the mold. Each of the plurality of heating units is operated with a predetermined relative output , and the lower heating region on the side of another adjacent processing chamber set at a lower temperature than the processing chamber in the processing chamber the amount of heat is given by Rukoto be to be more than the amount of heat applied to the upper side of the heating region of the other processing chamber side adjacent than the treatment chamber is set to a high temperature, in the one of the processing chamber Thereby alleviating the temperature gradient in the downward direction, it is a method of alleviating the temperature gradient in the transfer direction of the mold.

  When the optical element manufacturing method is such a method, the output during the heating operation is set so that each of the plurality of heating units provided in the processing chamber relaxes the temperature gradient in the processing chamber. The indoor temperature distribution can be kept uniform. As described above, according to the present invention, it is possible to prevent temperature differences due to portions in the processing chamber and temperature fluctuations with time, and to realize precise temperature management in the processing chamber. Therefore, the surface accuracy and shape accuracy of the optical element can be further improved.

  Further, the method for manufacturing an optical element of the present invention measures the temperature at a predetermined position in any of the processing chambers, compares the measured temperature with a preset target temperature, and determines the plurality of heating units according to the comparison result. Is a method of operating by the predetermined relative output.

  If the manufacturing method of the optical element is such a method, the measured temperature in the processing chamber is compared with the target set temperature, the comparison result is fed back, and the operation of the heating unit is controlled. For this reason, the temperature fluctuation with time can be suppressed to the minimum, the temperature distribution in the processing chamber can be kept uniform, and the surface accuracy and shape accuracy of the optical element can be further increased.

In the method of manufacturing an optical element of the present invention, the predetermined relative output is a relative output ratio of each heating unit.
If the manufacturing method of an optical element is made in this way, the relative output ratio can be determined in advance, and the heating unit can be operated with the relative output ratio. The relative output ratio indicates the ratio of the set output when the maximum output of the heating source of the heating unit is 100. This relative output ratio is set to a value that can relieve the temperature gradient in the processing chamber, similarly to the relative output. Therefore, by operating each heating unit with the relative output ratio, the temperature distribution in the processing chamber can be made uniform, and the surface accuracy and shape accuracy of the optical element can be further improved.

In the method of manufacturing an optical element of the present invention, the molding die includes an upper die and a lower die, and each of the plurality of heating units is operated with a predetermined relative output, whereby the upper die and the lower die are operated. This is a method of reducing the temperature difference.
When the manufacturing method of the optical element is such a method, the temperature difference between the upper mold and the lower mold is alleviated, so that the surface accuracy and shape accuracy of the optical element can be further improved.

Further, in the method for manufacturing an optical element of the present invention, in each of the plurality of processing chambers including a heating chamber, a press chamber, and a cooling chamber, the processing is simultaneously performed on a plurality of molding dies, and the plurality of moldings are performed. The mold is a method in which each mold is arranged in the transfer direction in each processing chamber.
If the optical element manufacturing method is such a method, when processing is simultaneously performed on a plurality of molds in one processing chamber, the surface accuracy and shape accuracy of each of the plurality of molds are extremely high. A high optical element can be obtained. In addition, by relaxing the temperature gradient in the transfer direction of the mold in the processing chamber, a uniform temperature can be applied to any of the plurality of molds arranged in the transfer direction. Therefore, in any of the plurality of molds, an optical element having very high surface accuracy and shape accuracy can be obtained.

As described above, according to the present invention, the output during the heating operation is set so as to control (relax, suppress) the temperature gradient in the processing chamber for each of the plurality of heating units provided in the processing chamber. Moreover, the measured temperature in the vicinity of the heating unit is compared with the preset temperature stored in advance, and the result is fed back to operate the heating unit. As a result, temperature differences due to parts in the processing chamber and temperature fluctuations over time can be prevented, and precise and strict temperature management in the processing chamber can be realized. As a result, the surface accuracy and shape accuracy of the optical element can be further improved. Can do. In particular, in the processing chamber, a plurality of the processing chambers are arranged in the vertical direction and in the transfer direction of the mold, and other adjacent processing chambers set at a lower temperature than the processing chamber inside the processing chamber. By controlling so that the amount of heat given to the heating area on the lower side nearer than the amount of heat given to the upper heating area near the other adjacent processing chamber set to a higher temperature than the processing chamber, It is possible to control a temperature gradient in the vertical direction in the processing chamber that causes a temperature difference between the upper die and the lower die and a temperature gradient in the transfer direction of the molding die. For this reason, the temperature distribution in the processing chamber can be made uniform, and therefore the surface accuracy and shape accuracy of the optical element can be further improved.

  Hereinafter, preferred embodiments of a mold press molding apparatus and an optical element manufacturing method according to the present invention will be described with reference to the drawings.

[Mold press molding equipment]
First, an embodiment of the mold press molding apparatus of the present invention will be described.
The mold press molding apparatus of this embodiment is similar to the conventional mold press molding apparatus already shown in FIG. 1 and includes an extraction / insertion chamber P1 and a plurality of processing chambers (first heating chamber P2, second heating chamber P3, A soaking chamber P4, a press chamber P5, a first annealing chamber P6, a second annealing chamber P7) and a quenching chamber P8 are provided, and these are arranged along the circumference. In addition, a rotary table 2 that rotates around the center of the circle is provided.

Next, the heating structure of the first heating chamber P2 among the plurality of processing chambers will be described with reference to FIGS.
3 is a longitudinal sectional view showing the internal structure of the first heating chamber P2 (AA sectional view of the mold press forming apparatus shown in FIG. 1), and FIG. 4 is a view of the first heating chamber P2 shown in FIG. It is BB sectional drawing.
In this embodiment, the structure of the first heating chamber P2 will be described as a representative example of the processing chamber. However, in the other processing chambers (other heating chambers, pressurizing chambers, slow cooling chambers), substantially the same structure is used. It can also be. However, the indoor temperature of each processing chamber is individually set according to the content of each processing.

As shown in FIG. 3, the first heating chamber (P2) 5 is formed in a case state by an outer surface member 51, an inner surface member 52, and an upper surface member 53. Inside the first heating chamber (P2) 5, a reflector 7 and a heating means 8 are formed. And are arranged.
As shown in FIG. 4, the heating unit 8 includes a plurality of heating units 8 a to 8 d. And each heating unit 8a-8d is supported in the state to which the strip | belt-shaped resistance heating element 81 meandered by the some support member 82 to the up-down direction.

The heating unit is provided on both the inner surface of the outer surface member 51 of the case 5 and the inner surface of the inner surface member 52 in a symmetric state with respect to the transfer direction of the mold. For example, four heating units can be provided on the inner surface of the outer surface member 51 and four heating units can be provided on the inner surface of the inner surface member 22, respectively. In this case, a total of eight heating units are provided in one processing chamber. become.
Further, a plurality of heating units are provided in at least one of the vertical direction and the transfer direction. The reason for providing a plurality in the vertical direction is to enable control of the temperature gradient in the vertical direction. The reason why a plurality of molds are provided in the transfer direction of the mold is to enable control of the temperature gradient in the transfer direction.

In FIG. 4, four heating units are provided, but the number is not limited to four, and may be two, three, or five or more. Further, the number of heating units provided in one processing chamber is not limited to eight, and may be seven or less or nine or more.
The reflection plate 7 reflects the heat generated from the heating means 8. Thereby, the heat can be efficiently given to the mold 4.

Next, the control system of the heating unit will be described with reference to FIG.
The control system 9 of the heating unit includes temperature sensors (temperature measuring means) Sa to Sd, a set temperature storage means 91, a comparison means 92, and a control means 93. The comparison unit 92 and the control unit 93 are collectively referred to as “control unit A”.

For example, a thermocouple or the like can be used as the temperature sensors Sa to Sd, and one or more temperature sensors Sa to Sd are provided for each heating range (hereinafter referred to as “heating area HA”). Specifically, as shown in FIG. 4, it can be provided in the vicinity of each of the heating units 8a to 8d.
When a plurality of the temperature sensors Sa to Sd are provided on the inner surface of the outer surface member 51, one temperature sensor (in this embodiment, the temperature sensor Sd) is used for measuring the temperature used for comparison with the set temperature (for control). For feedback). The other temperature sensors (temperature sensors Sa to Sc in this embodiment) are used for monitoring to monitor temperature fluctuations in the processing chamber.

In the present embodiment, four heating units are provided on the inner surface of the outer surface member 51. For this reason, a total of four or more temperature sensors are provided on the inner surface of the outer surface member 51 (a total of eight or more temperature sensors including the inner surface of the inner surface member 52 in one processing chamber). However, as will be described later, the temperature to be compared with the set temperature is only one of the four measured temperatures. For this reason, at least one temperature sensor is provided in the processing chamber.
In this embodiment, the temperature sensor Sd provided in the vicinity of the heating unit 8d is used as a control temperature sensor. However, the control temperature sensor is not limited to the temperature sensor Sd, and other temperature sensors may be used. It can also be used.

The set temperature storage unit 91 stores the set temperature in each heating area HA.
As shown in FIG. 6, the set temperature can be made different for each heating area HA.
Specifically, for example, the set temperature is 680 ° C. in the upper left heating area HAa, 700 ° C. in the upper right heating area HAb, and 730 ° C. in the lower left heating area HAc toward the inner surface of the outer surface member 51 of the processing chamber. In the lower right heating region HAd, it can be set to 750 ° C.

The comparison unit 92 compares the measured temperature sent from the control temperature sensor Sd with the set temperature taken out from the set temperature storage unit 91 and transmits the result to the control unit 93.
In this embodiment, there are a plurality of temperatures measured in the vicinity of the heating unit, but there is only one measured temperature to be compared with the set temperature. This is because when a plurality of measured temperatures are used and compared with the set temperature and fed back, the interference between the heating units is reflected in the feedback and the temperature control becomes unstable.

When the control unit 93 receives the comparison result from the comparison unit 92, the control unit 93 determines whether to operate the heating units 8a to 8d based on the comparison result. As a result of determination, when operating, each heating unit 8a-8d is operated based on a preset output ratio.
In addition, since the output ratio calculated in consideration of the temperature gradient in the processing chamber is preset in the plurality of heating units 8a to 8d, operation control is performed on all of the plurality of heating units 8a to 8d at a time. It is desirable to do.

Moreover, the control means 93 sets and memorize | stores the output ratio of each heating unit 8a-8d.
The output ratio indicates the ratio of the set output when the maximum output of the heating source of the heating unit is 100.
In the present embodiment, the set output when operating each heating unit is represented by “output ratio”, but the way of representing the set output is not limited to “output ratio”. Instead of a ratio, it can be expressed by a combination of output numerical values, such as “OOkW”.

Moreover, as shown in FIG. 6, an output ratio can be varied for each heating unit 8a-8d.
Specifically, for example, the output ratio of the heating unit 8a can be 55%, the heating unit 8b can be 60%, the heating unit 8c can be 65%, the heating unit 8d can be 70%, and the like.
These output ratios are calculated as those that provide the most uniform temperature (those that can suppress the temperature gradient generated in the processing chamber), and are set in advance before the production of the molded body is started by the mold press molding apparatus. The output ratio calculated and set in this way is preferably fixed thereafter. However, it goes without saying that the output ratio can be appropriately changed depending on the molding conditions depending on the volume of the molding material to be molded, the shape of the molded body, and the like.

Next, the setting of the output ratio and the set temperature will be described with reference to FIGS.
As shown in FIG. 5 or FIG. 7A, there are four heating areas HAa to HAd (upper left heating area HAa, upper right heating area HAb, lower left heating area HAc, lower right heating area HAd) in the processing chamber. There shall be. In addition, temperature sensors Sa to Sd are provided in the heating regions HAa to HAd, respectively.
Based on the measured temperature from each of the temperature sensors Sa to Sd, the control means 93 reveals the temperature distribution in the processing chamber. In the processing chamber, a temperature gradient is generated in the vertical direction due to heat convection, and a temperature gradient is also generated in the transfer direction of the mold due to temperature interference with the adjacent chamber.

As shown in FIG. 7B, when the temperature gradient in the vertical direction and the temperature gradient in the transfer direction of the mold are combined, the lower right heating area HAd in the processing chamber becomes relatively low temperature, and the upper left heating area HAa. Becomes hot.
In this case, in order to make the room temperature uniform, the amount of heat given to the lower right heating area HAd may be made larger than the amount of heat given to the upper left heating area HAa.

Therefore, as shown in FIG. 7C, the output ratio of the heating unit is set relatively high for the heating unit 8d in the lower right heating area HAd, while the heating unit in the upper left heating area HAa. 8a is set relatively low.
For example, 70% is set for the heating unit 8d in the lower right heating area HAd, 65% is set for the heating unit 8c in the lower left heating area HAc, and the heating unit 8b in the upper right heating area HAb is set. Is set to 60%, and 55% is set for the heating unit 8a in the upper left heating area HAa.

Further, as shown in FIG. 7D, the set temperature in the vicinity of each heating unit is set relatively high in the vicinity of the heating unit 8d in the lower right heating area HAd, while the upper left heating area. The vicinity of the heating unit 8a in HAa is set relatively low.
For example, 750 ° C. is set for the heating unit 8d in the lower right heating area HAd, 730 ° C. is set for the heating unit 8c in the lower left heating area HAc, and the heating unit 8b in the upper right heating area HAb is set. Is set to 700 ° C., and 680 ° C. is set for the heating unit 8a in the upper left heating area HAa.

In this way, by setting the output ratio and the set temperature in consideration of the temperature gradient in the vertical direction of the processing chamber and the temperature gradient in the transfer direction of the mold, the temperature gradient is controlled to control the temperature distribution in the processing chamber. Uniformity can be achieved.
The set temperature is sent to the set temperature storage unit 91 and stored therein. The output ratio is stored in the control means 93.

[Method for Manufacturing Optical Element]
Next, the manufacturing method of the optical element of this embodiment is demonstrated with reference to FIG.
This figure is a flowchart showing the operation procedure of the method of manufacturing the optical element of the present embodiment.
As shown in the figure, in the optical element manufacturing method of the present embodiment, first, a relative output setting step (step 10) and a set temperature storage step (step 11) are performed, and then a heating step (step). 12), a pressure molding process (step 13), a cooling process (step 14), etc. are performed.

In the relative output setting step, the output ratio of the plurality of heating units is set in the control means 93 for each heating unit so as to control the temperature gradient in the vertical direction in the processing chamber and the temperature gradient in the transfer direction of the mold. And memorized.
Next, in the set temperature storage step, the target temperature at a predetermined position in the processing chamber is stored in the set temperature storage unit 91 as the set temperature.
The relative output setting step and the set temperature storage step can also be performed as a preliminary experiment.

Thereafter, a heating process for heating the molding material accommodated in the mold, a pressure molding process for press-molding the heat-softened molding material, and a cooling process for cooling the molded body are sequentially performed.
While these heating process, pressure molding process, and cooling process are performed, in each processing chamber, as shown in FIG. 9, a temperature measurement process (step 20), a comparison process (step 21), a heating unit A control process (step 22) is performed.

In the temperature measurement step, the temperature at a predetermined position in the processing chamber is measured by the temperature sensors Sa to Sd.
In the comparison step, the measured temperature obtained in this temperature measurement step is compared with the set temperature stored in the set temperature storage step. That is, when the temperature measured by the temperature sensor Sd is sent to the comparison unit 92, the set temperature output from the set temperature storage unit 91 and the measurement temperature are converted into, for example, a voltage and compared.

In the heating unit control step, each of the plurality of heating units is operated by the output set in the relative output setting step based on the comparison result in the comparison step. That is, when the result of comparison by the comparison means 92 is sent to the control means 93, the control means 93 determines the contents of the comparison results. As a result of the determination, if the measured temperature is lower than the set temperature, the heating units 8a to 8d are operated.
By adopting such an optical element manufacturing method, it is possible to realize precise and strict temperature control in the processing chamber, so that the temperature distribution in the processing chamber is made uniform and the surface accuracy and shape system of the optical element are further improved. be able to. In addition, the temperature in the processing chamber is always managed, and when a difference from the set temperature occurs, the heating unit operates by being fed back, so that temperature fluctuations can be minimized.

  The preferred embodiments of the mold press molding apparatus and the optical element manufacturing method of the present invention have been described above. However, the mold press molding apparatus and the optical element manufacturing method according to the present invention are not limited to the above-described embodiments. Needless to say, various modifications can be made within the scope of the present invention.

For example, in the above-described embodiment, the first heating chamber has been described as a representative example of the processing chamber. However, the configuration illustrated in FIG. 1 is not limited to the first heating chamber, and can be realized in other processing chambers. It is.
In FIG. 1, the bottom member is not provided in the case, but the present invention can be realized even in a processing chamber provided with the bottom member.
Furthermore, in the above-described embodiment, the molding apparatus configured to perform various processes by transporting the molding die 4 along the circular transport path using the rotary table 2 has been described. The present invention can also be applied to a molding apparatus that employs a conveyance path.

  Since the present invention relates to temperature management in a processing chamber provided with heating means, it can be used for an apparatus that requires temperature management in a predetermined space.

It is a top view which shows the whole structure of a mold press molding apparatus. It is longitudinal direction sectional drawing which shows the internal structure of the conventional process chamber of a mold press molding apparatus. It is longitudinal direction sectional drawing which shows the internal structure of the 1st heating chamber in the mold press molding apparatus of this invention. It is BB sectional drawing of the 1st heating chamber shown by FIG. It is a block diagram which shows the control system of a heating unit. It is a graph which shows the specific example of each setting value of output ratio and setting temperature. FIG. 2 is an explanatory diagram showing a procedure for obtaining an output ratio and a set temperature for controlling a temperature gradient in a transfer direction of a mold, and (a) is a diagram showing a state of a processing chamber distributed to a plurality of heating regions; (B) is a graph showing the temperature distribution (temperature gradient) in the transfer direction of the mold, (c) is a diagram showing the relative relationship of the output ratio of the heating unit, and (d) is the relative temperature of the set temperature of the heating unit. It is a figure which shows a relationship. It is a manufacturing method of the optical element of this invention, Comprising: It is a flowchart which shows the operation | movement procedure of the manufacturing process of a molded object. It is a manufacturing method of the optical element of this invention, Comprising: It is a flowchart which shows the operation | movement procedure of operation control of a heating unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chamber 3 Support stand 4 Mold 5 Case 7 Reflector 8 Heating means 8a-8d Heating unit 9 Control system of heating unit 91 Set temperature storage means 92 Comparison means 93 Control means HAa-HAd Heating area Sa-Sd Temperature sensor (temperature) Measuring means)
P2 first heating chamber

Claims (7)

In a mold press molding apparatus comprising a plurality of processing chambers including a heating chamber, a press chamber, and a cooling chamber, and a transfer means for sequentially transferring a molding die containing a molding material to each of the processing chambers,
A plurality of heating units provided in at least one of the processing chambers;
Control means for operating each of the plurality of heating units based on a preset relative output to bring the indoor atmosphere to a predetermined temperature;
Wherein a plurality of heating units, in the interior of the processing chamber, a plurality each of the vertical direction and the transport direction of the mold, sequence and provided Rutotomoni,
The amount of heat given to the lower heating region near the other processing chamber that is set lower than the processing chamber in the processing chamber is set to a temperature higher than that of the processing chamber. A mold press molding apparatus characterized in that the amount of heat applied to the upper heating region near the room is larger . Set temperature storage means for storing a target temperature at a predetermined position in the processing chamber in which the heating unit is provided as a set temperature;
A plurality of temperature measuring means disposed in the processing chamber;
Comparing means for comparing the temperature measured by any one of the temperature measuring means with the set temperature output from the set temperature storage means,
2. The mold press molding apparatus according to claim 1 , wherein the control unit operates the plurality of heating units based on a comparison result from the comparison unit and the preset relative output. A molding die containing a molding material is transferred to a plurality of processing chambers including a heating chamber, a press chamber, and a cooling chamber, and a molding is obtained by performing each treatment including heating, pressing, and cooling on the molding die. In the manufacturing method of the optical element including
In at least one of the processing chambers, a plurality of heating units are arranged in the vertical direction and the transfer direction of the mold, respectively ,
Each of the plurality of heating units is operated by a predetermined relative output , and is given to a lower heating region on the side of another processing chamber adjacent to the processing chamber set at a lower temperature than the processing chamber. heat is by Rukoto be to be larger than the amount of heat applied to the upper side of the heating region of the other processing chamber side adjacent than the treatment chamber is set to a high temperature,
While relieving the temperature gradient in the vertical direction in any one of the processing chambers, the temperature gradient in the transfer direction of the mold is relieved ,
The manufacturing method. The temperature at a predetermined position in any one of the processing chambers is measured, the measured temperature is compared with a preset target temperature, and the plurality of heating units are controlled by the predetermined relative output according to the comparison result. Characterized by
The manufacturing method according to claim 3 . The manufacturing method according to claim 3 , wherein the predetermined relative output is a relative output ratio of each heating unit. The molding die includes an upper die and a lower die, and each of the plurality of heating units is operated by a predetermined relative output to relieve a temperature difference between the upper die and the lower die. Item 6. The production method according to any one of Items 3 to 5 . In each of the plurality of processing chambers including a heating chamber, a press chamber, and a cooling chamber, the processing is simultaneously performed on a plurality of molds, and the plurality of molds are arranged in the transfer direction in each processing chamber. The manufacturing method according to any one of claims 3 to 6 , wherein

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