JP2016000687A - Apparatus for supporting the setting of a manufacturing condition for silica glass crucible - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a silica glass crucible by a rotation mold method highly coincident in a three-dimensional shape for engineering data.SOLUTION: In the case where the coincidence of the three-dimensional shape between simulation data obtained on the basis of the initial physical parameter and measurement data is lower than a predetermined standard, there are set improvement physical property parameters, at which the coincidence is at or higher than a predetermined standard. In the case where the coincidence between the simulation data obtained on the basis of the initial manufacturing condition and the three-dimensional shape of the measurement data is lower than a predetermined standard, an improved manufacturing condition is set in the rotation mold method, by which the simulation data having a coincidence with the design data is at or higher than a predetermined standard. As a result, the coincidence in the three-dimensional shape between the design data of a silica glass crucible and the measured data is enhanced to a predetermined standard or higher, thereby to enhance the coincidence of the three-dimensional shape for the design data.

Description

  The present invention relates to an apparatus that supports setting of manufacturing conditions for a silica glass crucible.

  The silica glass crucible manufacturing method includes, for example, a silica powder layer forming step of depositing silica powder having an average particle size of about 300 μm on the inner surface of the rotary mold to form a silica powder layer, and reducing the silica powder layer from the mold side. However, an arc melting step of forming a silica glass layer by arc melting the silica powder layer is provided (this method is referred to as “rotary molding method”).

  At the initial stage of the arc melting process, the silica powder layer is strongly depressurized to remove bubbles to form a transparent silica glass layer (hereinafter referred to as “transparent layer”). By forming a residual bubble-containing silica glass layer (hereinafter referred to as “bubble-containing layer”), a two-layered silica glass having a transparent layer on the inner surface side and a bubble-containing layer on the outer surface side A crucible can be formed.

  On the other hand, in order to produce a silicon single crystal by using a silica glass crucible by a Czochralski (hereinafter referred to as CZ) method, a solid-liquid interface shape between a silicon single crystal as a solid and a silicon melt as a liquid is used. In addition, a method of numerically analyzing the temperature distribution in the vicinity of the solid-liquid interface by computer simulation has been vigorously developed.

  For example, in Patent Document 1, physical property values of each member of a hot zone modeled with a mesh structure are input to a computer, and the surface temperature distribution of each member is obtained based on the amount of heat generated by the heater and the radiation rate of each member. Is described.

JP 2009-190926 A

  However, the prior art described in Patent Document 1 has been difficult to use for simulation when a silica glass crucible is manufactured by a rotational mold method. And when manufacturing a silica glass crucible by a rotational mold method, the silica glass crucible of the three-dimensional shape different from design data is often obtained by various factors. Therefore, until now, it has been difficult to actually manufacture a silica glass crucible having the same three-dimensional shape as the design data by the rotational molding method.

  The present invention has been made in view of the above circumstances, and an object thereof is to manufacture a silica glass crucible having a high degree of coincidence of three-dimensional shapes with design data by a rotational mold method.

  ADVANTAGE OF THE INVENTION According to this invention, the apparatus which assists the setting of the manufacturing conditions by the rotational molding method of a silica glass crucible is provided. This device includes a design data acquisition unit that acquires design data of a three-dimensional shape of a silica glass crucible of an arbitrary model, production lot, or serial number, and manufacturing conditions of the silica glass crucible by the rotational molding method based on the design data. Using a manufacturing condition data setting unit for setting data and a calculation engine capable of one or more types selected from the group consisting of heat transfer calculation, fluid calculation and structure calculation, the silica glass crucible obtained according to the manufacturing conditions A simulation unit for obtaining three-dimensional shape simulation data, a physical property parameter setting unit for setting physical property parameters used by the calculation engine, and measurement of the three-dimensional shape of a silica glass crucible manufactured by a rotational mold method based on the manufacturing conditions Measurement data acquisition unit that acquires data, its design data, and its simulation Yondeta compares control two types of data among the measurement data includes a coincidence determination unit determines the degree of coincidence of the three-dimensional shape of both the output of the simulation data or manufacturing condition data.

  In addition, the physical property parameter setting unit, when the degree of coincidence of the three-dimensional shape of the simulation data and the measurement data obtained based on the initial physical property parameter is below a predetermined level, the degree of coincidence is predetermined. It has an improved physical property parameter setting unit for setting an improved physical property parameter that is equal to or higher than the standard. The manufacturing condition setting unit includes an improved manufacturing condition data setting unit that sets the manufacturing conditions in the rotational mold method for obtaining simulation data whose degree of coincidence with the design data is equal to or higher than a predetermined level.

  According to this configuration, when the degree of coincidence of the three-dimensional shape of the simulation data and measurement data obtained based on the initial physical property parameters is below a predetermined level, the degree of coincidence is equal to or higher than the predetermined level. Since the improved physical property parameters are set, the degree of coincidence between the three-dimensional shapes of the simulation data and the measurement data can be increased to a predetermined level or more. In addition, according to this configuration, the degree of coincidence between the design data and the simulation data is set in order to set the manufacturing conditions in the rotational mold method in which the simulation data with which the degree of coincidence with the design data is a predetermined level or more can be obtained. Can be raised above a predetermined level. As a result, according to this configuration, the degree of coincidence of the three-dimensional shape of the design data and measurement data of the silica glass crucible can be increased to a predetermined level or more. That is, according to this configuration, a silica glass crucible having a high degree of coincidence of three-dimensional shapes with respect to design data can be manufactured by a rotational mold method.

Moreover, according to this invention, the apparatus which produces | generates the simulation data obtained by said apparatus is provided.

  The degree of coincidence of the simulation data and the measurement data in the three-dimensional shape is not less than a predetermined level as described above. Therefore, if this simulation data is used, the three-dimensional shape of the silica glass crucible actually manufactured by the rotational mold method can be accurately predicted.

  Moreover, according to this invention, the apparatus which produces | generates the improved manufacturing condition data obtained by said apparatus is provided.

  When this improved manufacturing condition data is used, simulation data is obtained in which the degree of coincidence with the design data is a predetermined level or higher as described above. When using the above apparatus, if the degree of coincidence of the three-dimensional shape of the simulation data and measurement data obtained based on the original physical property parameters is below a predetermined level as described above, the coincidence Since the improved physical property parameter is set so that the degree is equal to or higher than a predetermined level, the degree of coincidence between the three-dimensional shapes of the simulation data and the measurement data can be increased to a predetermined level or higher. Therefore, if this improved production condition data is used, a silica glass crucible having a high degree of coincidence of the three-dimensional shape with respect to the design data can be produced by the rotational mold method.

  According to the present invention, a silica glass crucible having a high degree of coincidence of a three-dimensional shape with design data can be manufactured by a rotational mold method.

It is a conceptual diagram for demonstrating the operation principle of the apparatus of this embodiment. It is a conceptual diagram for demonstrating performing feedback control of the arc power supply and pressure-reduction mechanism more precisely in the manufacturing process of a silica glass crucible using the improved manufacturing condition data obtained using the apparatus of the present embodiment. It is a functional block diagram for demonstrating the whole structure of the apparatus of this embodiment. It is a functional block diagram for demonstrating the detailed structure of the simulation part of the apparatus of this embodiment, a manufacturing condition data setting part, and a physical property parameter setting part. It is a data table for demonstrating the data structure of the measurement data of the silica glass crucible used with the apparatus of this embodiment. It is a flowchart for demonstrating operation | movement of the apparatus of this embodiment. It is a measurement process figure for demonstrating the method of measuring the measurement data of the silica glass crucible used with the apparatus of this embodiment using a robot arm and a ranging part. It is a conceptual diagram for demonstrating the measurement principle in FIG. It is a graph which shows the measurement result of the internal ranging part in FIG. It is a graph which shows the measurement result of the external ranging part in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

<Apparatus for supporting setting of manufacturing conditions for silica glass crucible>
FIG. 1 is a conceptual diagram for explaining the operation principle of the apparatus according to the present embodiment. When setting the manufacturing conditions of the silica glass crucible using the apparatus of the present embodiment, first, design data for designing the silica glass crucible with three-dimensional CAD or the like is prepared. The three-dimensional CAD design data may be obtained by converting two-dimensional CAD design data into three-dimensional CAD design data.

  Next, production condition data (for example, a time table such as arc power, decompression condition, mold rotation speed) for producing a silica glass crucible is set based on the design data. In this case, as the initial manufacturing condition data, for example, manufacturing condition data determined by a skilled operator or engineer as appropriate based on past knowledge and experience may be set. Alternatively, as the initial production condition data, the production condition data in which the result of quality inspection of the silica glass crucible of a predetermined type was satisfactory in the past production record of the silica glass crucible may be used as it is.

  Then, using this initially set manufacturing condition data, a silica glass crucible manufacturing apparatus equipped with a power source, a carbon electrode, a carbon mold, a decompression mechanism, and the like is used. To produce a silica glass crucible. Specifically, a silica powder layer forming step of depositing silica powder having an average particle size of about 300 μm on the inner surface of the rotary mold to form a silica powder layer, and the silica powder layer while reducing the pressure of the silica powder layer from the mold side A silica glass crucible is produced by an arc melting step of forming a silica glass layer by arc melting.

  At this time, at the initial stage of the arc melting process, the silica powder layer is strongly depressurized to remove bubbles to form a transparent layer, and then the depressurization is weakened to form a bubble-containing layer in which bubbles remain. A two-layered silica glass crucible having a transparent layer on the inner surface side and a bubble-containing layer on the outer surface side can be formed.

  And the three-dimensional shape of this silica glass crucible is measured using the robot arm mentioned later, and the measurement data of the three-dimensional shape of a silica glass crucible are obtained.

  In addition, simulation data of the three-dimensional shape of the silica glass crucible assumed to be obtained when the silica glass crucible is manufactured using the above-mentioned initially set manufacturing condition data, for example, numerical analysis such as stress analysis and thermal fluid analysis Generate using a technique. At this time, physical property parameters (for example, density, dielectric constant, magnetic permeability, magnetic susceptibility, rigidity, Young's modulus, electrical conductivity, polarization, etc. for carbon mold, natural quartz powder, synthetic silica powder, transparent layer, bubble-containing layer, etc. Rate, hardness, specific heat, linear expansion coefficient, boiling point, melting point, glass transition point, heat transfer coefficient, Poisson's ratio, etc.). As these physical property parameters, default physical property parameters attached to commercially available simulation software can be used as initial physical property parameters. Alternatively, a physical property parameter determined to be appropriate by a skilled operator or engineer based on past knowledge and experience may be set.

  Thereafter, when the degree of coincidence between the simulation data and measurement data obtained as described above is calculated and the degree of coincidence falls below a predetermined level, carbon mold, natural quartz powder, synthetic silica powder, transparent layer, air bubbles The physical property parameter for the contained layer is changed, and the simulation is repeated until the degree of coincidence becomes a predetermined level or higher. As a result, the physical property parameter having the matching degree equal to or higher than a predetermined level is adopted as the improved physical property parameter. As the index indicating the degree of coincidence, various existing pattern matching methods can be used.

  Subsequently, when the degree of coincidence between the design data and the simulation data using the improved physical property parameter is calculated and the degree of coincidence is lower than a predetermined level, production condition data for producing a silica glass crucible (for example, , The arc power, the decompression condition, the time table of the mold rotation speed, etc.) are changed, and the simulation is repeated until the above-mentioned degree of coincidence becomes a predetermined level or more. As a result, the manufacturing condition data in which the degree of coincidence is equal to or higher than a predetermined level is adopted as the improved manufacturing condition data. As an index indicating the degree of coincidence, various existing pattern matching methods can be similarly used.

  In this way, if the degree of coincidence of the three-dimensional shape of the simulation data and measurement data obtained based on the initial physical property parameters is below a predetermined level, the degree of coincidence is equal to or higher than the predetermined level. Since the improved physical property parameters are set, the degree of coincidence between the three-dimensional shapes of the simulation data and the measurement data can be increased to a predetermined level or more. In addition, in this way, in order to set the manufacturing conditions for obtaining simulation data with a degree of coincidence with the design data equal to or higher than a predetermined level, the degree of coincidence between the three-dimensional shapes of the design data and the simulation data is equal to or higher than the predetermined level. Can be increased. As a result, in this way, the degree of coincidence of the three-dimensional shape of the design data and measurement data of the silica glass crucible can be increased to a predetermined level or more. That is, in this way, a silica glass crucible having a high degree of coincidence of the three-dimensional shape with respect to the design data can be manufactured by the rotational mold method.

  FIG. 2 is a concept for explaining that the feedback control of the arc power source and the decompression mechanism is more precisely performed in the manufacturing process of the silica glass crucible using the improved manufacturing condition data obtained by using the apparatus of the present embodiment. FIG. By using the improved manufacturing condition data obtained by using the method described in FIG. 1, as shown in this figure, more precise feedback is applied in the time table of arc power, pressure reduction conditions, mold rotation speed, and the like. Can do. As a result, a silica glass crucible having a high degree of coincidence of the three-dimensional shape with the design data can be manufactured by the rotational mold method.

  FIG. 3 is a functional block diagram for explaining the overall configuration of the apparatus of the present embodiment. The manufacturing condition setting support apparatus 1000 is provided with a design data acquisition unit 104 that acquires design data of a three-dimensional shape of a silica glass crucible of an arbitrary model, manufacturing lot, or serial number. The design data acquisition unit 104 can acquire the design data of the three-dimensional shape of the silica glass crucible input by the skilled operator or engineer through the operation unit 124. Further, the design data acquisition unit 104 may acquire the design data of the three-dimensional shape of the silica glass crucible stored in the external server 126 via the network 118.

  The manufacturing condition setting support apparatus 1000 is provided with a manufacturing condition data setting unit 140 that sets manufacturing condition data for a silica glass crucible based on design data. The manufacturing condition data setting unit 140 uses silica glass crucible manufacturing condition data (for example, a time table of arc power, decompression conditions, mold rotation speed, etc.) input by an experienced operator or engineer through the operation unit 124 as the initial manufacturing conditions. It can be set as data. In addition, the manufacturing condition data setting unit 140 stores the manufacturing condition data in which the result of the quality inspection of the silica glass crucible of a predetermined type is good in the past silica glass crucible manufacturing record stored in the external server 126. You may acquire via the network 118. FIG.

  This production condition setting support apparatus 1000 uses a calculation engine capable of one or more types selected from the group consisting of heat transfer calculation, fluid calculation and structure calculation, and uses a silica glass crucible obtained according to the above manufacturing conditions. A simulation unit 112 is provided that obtains three-dimensional shape simulation data using a numerical analysis method such as stress analysis and thermal fluid analysis. In addition, the manufacturing condition setting support apparatus 1000 is provided with a physical property parameter setting unit 106 that sets physical property parameters used by the calculation engine of the simulation unit 112 described above. This physical property parameter setting unit 106 is a physical property parameter (for example, density, dielectric constant, etc.) for a carbon mold, natural quartz powder, synthetic silica powder, transparent layer, bubble-containing layer, etc. input by an experienced operator or engineer through the operation unit 124. Magnetic permeability, magnetic susceptibility, rigidity, Young's modulus, electrical conductivity, polarizability, hardness, specific heat, linear expansion coefficient, boiling point, melting point, glass transition point, heat transfer coefficient, Poisson's ratio, etc.) are set as initial physical property parameters be able to. Alternatively, the physical property parameter setting unit 106 may acquire the physical property parameters stored in the external server 126 via the network 118. Alternatively, the physical property parameter setting unit 106 can use a default physical property parameter attached to commercially available simulation software stored in the physical property parameter storage unit 142 as the initial physical property parameter.

  The manufacturing condition setting support apparatus 1000 includes a measurement data acquisition unit 102 that acquires measurement data of a three-dimensional shape of a silica glass crucible actually manufactured based on the above manufacturing conditions. The measurement data acquisition unit 102 can directly acquire measurement data from the measurement device 128 described later via the network 118. Alternatively, the measurement data acquisition unit 102 may acquire the measurement data of the three-dimensional shape of the silica glass crucible stored in the external server 126 via the network 118.

  The manufacturing condition setting support device 1000 compares and contrasts two types of data among the design data, the simulation data, and the measurement data, and determines the degree of coincidence between the three-dimensional shapes. A portion 114 is provided. The coincidence degree determination unit 114 only needs to be able to perform various existing pattern matching methods. As such a pattern matching method, residual matching, normalized correlation method, phase-only correlation, geometric matching, vector correlation, generalized Hough transform, or the like can be suitably used.

  The manufacturing condition setting support apparatus 1000 is provided with an output unit 116 for simulation data or manufacturing condition data. The output unit 116 can output simulation data or manufacturing condition data as image data through the image display unit 122. The output unit 116 can also output simulation data or manufacturing condition data to the image display unit 130, the printer 132, the server 134, and the like via the network 120.

  FIG. 4 is a functional block diagram for explaining detailed configurations of the simulation unit, the manufacturing condition data setting unit, and the physical property parameter setting unit of the apparatus according to the present embodiment. As shown in this figure, the simulation unit 112 is provided with a calculation engine storage unit 210 for storing a heat transfer calculation engine 204, a fluid calculation engine 206, a structural calculation engine 208, and the like. The simulation unit 112 reads the heat transfer calculation engine 204, the fluid calculation engine 206, and the structural calculation engine 208 from the calculation engine storage unit 210, and performs numerical analysis such as stress analysis and thermal fluid analysis. 202 is also provided.

  In the physical property parameter setting unit 106, when the degree of coincidence of the three-dimensional shape of the simulation data and measurement data obtained based on the initial physical property parameter is below a predetermined level, the degree of coincidence is a predetermined level. An improved physical property parameter setting unit 402 for setting the improved physical property parameters as described above is provided. When the coincidence determination unit 114 calculates the coincidence between the simulation data and the measurement data and the coincidence is below a predetermined level, the coincidence determination unit 114 receives a physical property parameter change instruction from the physical property parameter setting unit 106. hand over. Then, the improved physical property parameter setting unit 402 of the physical property parameter setting unit 106 that has received this change command, for example, the physical property parameters (for example, density) for carbon mold, natural quartz powder, synthetic silica powder, transparent layer, bubble-containing layer, etc. , Dielectric constant, magnetic permeability, magnetic susceptibility, rigidity, Young's modulus, electrical conductivity, polarizability, hardness, specific heat, linear expansion coefficient, boiling point, melting point, glass transition point, heat transfer coefficient, Poisson's ratio, etc.). The improved physical property parameter thus changed is transferred to the simulation unit 112. The simulation unit 112 that has received the improved physical property parameter performs a simulation again using the improved physical property parameter, and passes the simulation result to the coincidence degree determination unit 114. This series of operations is repeated until the degree of coincidence reaches a predetermined level or higher.

  The manufacturing condition data setting unit 140 is provided with an improved manufacturing condition setting unit 308 that sets manufacturing conditions for obtaining simulation data having a degree of coincidence with design data equal to or higher than a predetermined level. The improved manufacturing condition setting unit 308 includes an arc discharge condition setting unit 302, a rotation speed setting unit 304, and a pressure reduction condition setting unit 306. When the coincidence determination unit 114 calculates the coincidence between the design data and the simulation data and the coincidence is below a predetermined level, the coincidence determination unit 114 instructs the production condition data setting unit 140 to change the production condition data. Hand over. Upon receiving this change command, the improved manufacturing condition setting unit 308 of the manufacturing condition data setting unit 140 sends the manufacturing condition data (for example, arc power) to the arc discharge condition setting unit 302, the rotation speed setting unit 304, and the decompression condition setting unit 306. , Time conditions such as decompression conditions and mold rotation speed) are changed. The improved manufacturing condition data thus changed is transferred to the simulation unit 112. The simulation unit 112 that has received the improved manufacturing condition data performs a simulation again using the improved manufacturing condition data, and passes the simulation result to the coincidence degree determination unit 114. This series of operations is repeated until the degree of coincidence reaches a predetermined level or higher.

  FIG. 5 is a data table for explaining the data structure of the measurement data of the silica glass crucible used in the apparatus of this embodiment. As shown in this figure, the measurement data acquisition unit 102 can directly acquire measurement data having a data structure as shown in this figure via a network 118 from a measurement device 128 described later. In this measurement data, for each position A, position B, position C, position D, position E, data such as inner XYZ coordinates, outer XYZ coordinates, bubble content, FT-IR spectrum, Raman spectrum, surface roughness, etc. Are recorded in table format.

  FIG. 6 is a flowchart for explaining the operation of the apparatus of this embodiment. First, the power of the manufacturing condition setting support apparatus 1000 is turned on and a series of operations is started. Then, first, the design data acquisition unit 104 acquires the design data of the three-dimensional shape of the silica glass crucible stored in the external server 126 via the network 118 (S102). Next, the manufacturing condition data setting unit 140 stores the manufacturing condition data in which the result of the quality inspection of the silica glass crucible of a predetermined type is good in the past silica glass crucible manufacturing record stored in the external server 126. Obtained via the network 118 (S104).

  Subsequently, the physical property parameter setting unit 106 acquires the physical property parameters stored in the external server 126 via the network 118 (S106). And the simulation part 112 obtains the simulation data of the three-dimensional shape of the silica glass crucible obtained by said manufacturing conditions using numerical analysis methods, such as a stress analysis and a thermal fluid analysis (S108).

  On the other hand, the silica glass crucible is actually manufactured by melting the silica powder laminated on the mold using the silica glass crucible manufacturing equipment equipped with the power supply, carbon electrode, carbon mold, decompression mechanism, etc. (S110). And the measurement data acquisition part 102 acquires the measurement data of the three-dimensional shape of the silica glass crucible actually manufactured based on said manufacturing conditions (S112).

  Thereafter, the coincidence determination unit 114 compares and compares the simulation data and the measurement data, and determines the coincidence between the three-dimensional shapes (S114). Specifically, the coincidence determination unit 114 calculates the coincidence between the simulation data and the measurement data, and determines whether the coincidence is below a predetermined level (S116). If the degree of coincidence between the simulation data and the measurement data is below a predetermined level, the improved physical property parameter setting unit 402 sets an improved physical property parameter that causes the degree of coincidence to be equal to or higher than the predetermined level (S118). In this case, the simulation unit 112 restarts the simulation using the improved physical property parameter. On the other hand, if the degree of coincidence between the simulation data and the measurement data is equal to or higher than a predetermined level, the physical property parameter is used as it is.

  Next, the coincidence determination unit 114 compares and contrasts the design data and the simulation data, and determines the coincidence between the three-dimensional shapes (S120). Specifically, the coincidence determination unit 114 calculates the coincidence between the design data and the simulation data, and determines whether the coincidence is below a predetermined level (S122). If the degree of coincidence between the design data and the simulation data is below a predetermined level, the improved manufacturing condition setting unit 308 sets the improved manufacturing condition data that makes the degree of coincidence equal to or higher than the predetermined level (S124). In this case, the simulation unit 112 restarts the simulation using the improved manufacturing condition data. On the other hand, when the degree of coincidence between the design data and the simulation data is equal to or higher than a predetermined level, the manufacturing condition data is used as it is. Then, the output unit 116 outputs the simulation data or the manufacturing condition data to the image display unit 130, the printer 132, the server 134, etc. via the network 120 (S126). This completes a series of operations.

<Three-dimensional shape measuring device for silica glass crucible>
Hereinafter, the three-dimensional shape measurement method of the silica glass crucible for obtaining the measurement data of the three-dimensional shape of the silica glass crucible used in the above embodiment will be described with reference to FIGS.

<Silica glass crucible>
FIG. 7 is a measurement process diagram for explaining a method of measuring the measurement data of the silica glass crucible used in the apparatus of this embodiment using a robot arm and a distance measuring unit. The silica glass crucible 11 to be measured has a transparent layer 13 on the inner surface side and a bubble-containing layer 15 on the outer surface side, and is mounted on a turntable 9 that can be rotated so that the opening portion faces downward. Is placed. The silica glass crucible 11 has a round part 11b having a relatively large curvature, a cylindrical side wall part 11a having an edge opened on the upper surface, and a mortar-shaped bottom part 11c made of a straight line or a curve having a relatively small curvature. In this embodiment, a round part is a part which connects the side wall part 11a and the bottom part 11c, from the point where the tangent of the curve of the round part overlaps with the side wall part 11a of the silica glass crucible, to the point having a common tangent with the bottom part 11c Means the part. In other words, the point where the side wall part 11a of the silica glass crucible 11 starts to bend is the boundary between the side wall part 11a and the round part 11b. Further, the portion where the curvature of the bottom of the crucible is constant is the bottom portion 11c, and the point where the curvature starts to change when the distance from the center of the bottom of the crucible increases is the boundary between the bottom portion 11c and the round portion 11b.

<Internal robot arm, internal ranging unit>
On the base 1 provided at a position covered with the crucible 11, an internal robot arm 5 is installed. The internal robot arm 5 includes a plurality of arms 5a, a plurality of joints 5b that rotatably support these arms 5a, and a main body 5c. The main body 5c is provided with an external terminal (not shown) so that data exchange with the outside is possible. An internal distance measuring unit 17 for measuring the inner surface shape of the crucible 11 is provided at the tip of the internal robot arm 5. The internal distance measuring unit 17 measures the distance from the internal distance measuring unit 17 to the inner surface of the crucible 11 by irradiating the inner surface of the crucible 11 with laser light and detecting reflected light from the inner surface. A control unit that controls the joint 5b and the internal distance measuring unit 17 is provided in the main body 5c. The control unit moves the internal distance measuring unit 17 to an arbitrary three-dimensional position by rotating the joint 5b and moving the arm 5 based on a program provided in the main body 5c or an external input signal. Specifically, the internal distance measuring unit 17 is moved in a non-contact manner along the inner surface of the crucible. Therefore, rough shape data of the inner surface of the crucible is given to the control unit, and the position of the internal distance measuring unit 17 is moved according to the data. More specifically, for example, the measurement is started from a position close to the vicinity of the opening of the crucible 11 as shown in FIG. 7A, and toward the bottom 11c of the crucible 11 as shown in FIG. 7B. The internal distance measuring unit 17 is moved to perform measurement at a plurality of measurement points on the movement path. The measurement interval is, for example, 1 to 5 mm, for example, 2 mm. The measurement is performed at a timing stored in the internal distance measuring unit 17 in advance or according to an external trigger. The measurement results are stored in the storage unit in the internal distance measuring unit 17, and are sent to the main body unit 5c collectively after the measurement is completed, or are sequentially sent to the main body unit 5c for each measurement. The internal distance measuring unit 17 may be configured to be controlled by a control unit provided separately from the main body 5c.

  When the measurement from the opening of the crucible to the bottom 11c is completed, the turntable 9 is slightly rotated and the same measurement is performed. This measurement may be performed from the bottom 11c toward the opening. The rotation angle of the turntable 9 is determined in consideration of accuracy and measurement time, and is, for example, 2 to 10 degrees. If the rotation angle is too large, the measurement accuracy is not sufficient, and if it is too small, it takes too much measurement time. The rotation of the turntable 9 is controlled based on a built-in program or an external input signal. The rotation angle of the turntable 9 can be detected by a rotary encoder or the like. The rotation of the turntable 9 is preferably interlocked with the movement of the internal distance measuring unit 17 and the external distance measuring unit 19 described later, so that the three-dimensional coordinates of the internal distance measuring unit 17 and the external distance measuring unit 19 can be changed. Calculation becomes easy.

  As will be described later, the internal distance measuring unit 17 includes a distance from the internal distance measuring unit 17 to the inner surface (inner surface distance) and a distance from the inner distance measuring unit 17 to the interface between the transparent layer 13 and the bubble-containing layer 15 (interface). Both distances can be measured. Since the angle of the joint 5b is known by a rotary encoder or the like provided in the joint 5b, the three-dimensional coordinates and direction of the position of the internal distance measuring unit 17 at each measurement point are known. Is obtained, the three-dimensional coordinates on the inner surface and the three-dimensional coordinates on the interface are known. And since the measurement from the opening part of the crucible 11 to the bottom part 11c is performed over the perimeter of the crucible 11, the three-dimensional shape of the inner surface of the crucible 11 and the three-dimensional shape of the interface become known. Further, since the distance between the inner surface and the interface is known, the thickness of the transparent layer 13 is also known, and a three-dimensional distribution of the thickness of the transparent layer is obtained.

<External robot arm, external distance measuring unit>
An external robot arm 7 is installed on a base 3 provided outside the crucible 11. The external robot arm 7 includes a plurality of arms 7a, a plurality of joints 7b that rotatably support these arms, and a main body portion 7c. The main body 7c is provided with an external terminal (not shown) so that data exchange with the outside is possible. An external distance measuring unit 19 that measures the outer surface shape of the crucible 11 is provided at the tip of the external robot arm 7. The external distance measuring unit 19 measures the distance from the external distance measuring unit 19 to the outer surface of the crucible 11 by irradiating the outer surface of the crucible 11 with laser light and detecting the reflected light from the outer surface. A control unit that controls the joint 7b and the external distance measuring unit 19 is provided in the main body 7c. The control unit moves the external distance measuring unit 19 to an arbitrary three-dimensional position by rotating the joint 7b and moving the arm 7 based on a program provided in the main body unit 7c or an external input signal. Specifically, the external distance measuring unit 19 is moved in a non-contact manner along the outer surface of the crucible. Therefore, rough shape data of the outer surface of the crucible is given to the control unit, and the position of the external distance measuring unit 19 is moved according to the data. More specifically, for example, the measurement is started from a position close to the vicinity of the opening of the crucible 11 as shown in FIG. 7A, and toward the bottom 11c of the crucible 11 as shown in FIG. 7B. The external distance measuring unit 19 is moved to perform measurement at a plurality of measurement points on the movement path. The measurement interval is, for example, 1 to 5 mm, for example, 2 mm. The measurement is performed at a timing stored in advance in the external distance measuring unit 19 or according to an external trigger. The measurement results are stored in the storage unit in the external distance measuring unit 19 and are collectively sent to the main unit 7c after the measurement is completed, or are sequentially sent to the main unit 7c every measurement. The external distance measuring unit 19 may be configured to be controlled by a control unit provided separately from the main body unit 7c.

  The internal distance measuring unit 17 and the external distance measuring unit 19 may be moved in synchronization. However, since the measurement of the inner surface shape and the measurement of the outer surface shape are performed independently, it is not always necessary to synchronize.

  The external distance measuring unit 19 can measure the distance (outer surface distance) from the external distance measuring unit 19 to the outer surface. Since the angle of the joint 7b is known by a rotary encoder or the like provided in the joint 7b, the three-dimensional coordinates and direction of the position of the external distance measuring unit 19 are known. The three-dimensional coordinates are known. And since the measurement from the opening part of the crucible 11 to the bottom part 11c is performed over the perimeter of the crucible 11, the three-dimensional shape of the outer surface of the crucible 11 becomes known. From the above, since the three-dimensional shape of the inner surface and the outer surface of the crucible becomes known, a three-dimensional distribution of the wall thickness of the crucible is obtained.

<Details of distance measurement>
Next, details of distance measurement by the internal distance measuring unit 17 and the external distance measuring unit 19 will be described with reference to FIG.
As shown in FIG. 8, the internal distance measuring unit 17 is arranged on the inner surface side (transparent layer 13 side) of the crucible 11, and the external distance measuring unit 19 is arranged on the outer surface side of the crucible 11 (bubble containing layer 15 side). Placed in. The internal distance measuring unit 17 includes an emitting unit 17a and a detecting unit 17b. The external distance measuring unit 19 includes an emitting unit 19a and a detecting unit 19b. The internal distance measuring unit 17 and the external distance measuring unit 19 include a control unit and an external terminal (not shown). The emitting portions 17a and 19a emit laser light, and include, for example, a semiconductor laser. The wavelength of the emitted laser light is not particularly limited, but is, for example, red laser light having a wavelength of 600 to 700 nm. The detectors 17b and 19b are composed of, for example, a CCD, and the distance to the target is determined based on the principle of triangulation based on the position where the light hits.

  A part of the laser light emitted from the emitting part 17a of the internal distance measuring part 17 is reflected by the inner surface (the surface of the transparent layer 13), and partly reflected by the interface between the transparent layer 13 and the bubble-containing layer 15, These reflected lights (inner surface reflected light and interface reflected light) strike the detection unit 17b and are detected. As is apparent from FIG. 8, the inner surface reflected light and the interface reflected light hit different positions of the detection unit 17b. Due to the difference in position, the distance from the inner distance measuring unit 17 to the inner surface (inner surface distance) and The distance to the interface (interface distance) is determined. A suitable incident angle θ may vary depending on the state of the inner surface, the thickness of the transparent layer 13, the state of the bubble-containing layer 15, etc., but is, for example, 30 to 60 degrees.

  FIG. 9 shows the actual measurement results measured using a commercially available laser displacement meter. As shown in FIG. 9, two peaks are observed, the near-side peak is a peak due to the inner surface reflected light, and the far-side peak corresponds to a peak due to the interface reflected light. Thus, the peak due to the reflected light from the interface between the transparent layer 13 and the bubble-containing layer 15 is also clearly detected. Conventionally, the interface has not been specified in this way, and this result is very novel.

  If the distance from the internal distance measuring unit 17 to the inner surface is too far, or if the inner surface or interface is locally inclined, two peaks may not be observed. In that case, it is possible to search the position and angle at which two peaks are observed by bringing the internal distance measuring unit 17 closer to the inner surface or by tilting the internal distance measuring unit 17 to change the emission direction of the laser light. preferable. Further, even if the two peaks are not observed simultaneously, the peak due to the inner surface reflected light may be observed at a certain position and angle, and the peak due to the interface reflected light may be observed at another position and angle. In order to prevent the internal distance measuring unit 17 from coming into contact with the inner surface, a maximum proximity position is set so that even if no peak is observed, the inner distance measuring unit 17 cannot be closer to the inner surface than that position. preferable.

  In addition, when there are independent bubbles in the transparent layer 13, the internal distance measuring unit 17 may detect the reflected light from the bubbles, and the interface between the transparent layer 13 and the bubble-containing layer 15 may not be detected properly. is there. Therefore, when the position of the interface measured at a certain measurement point A is greatly deviated (exceeding a predetermined reference value) from the position of the interface measured at the preceding and following measurement points, the data at the measurement point A is It may be excluded. In that case, data obtained by performing measurement again at a position slightly deviated from the measurement point A may be employed.

  The laser light emitted from the emitting portion 19a of the external distance measuring section 19 is reflected by the surface of the outer surface (bubble-containing layer 15), and the reflected light (outer surface reflected light) strikes the detecting portion 19b and is detected. The distance between the external distance measuring unit 19 and the outer surface is determined based on the detection position on the detection unit 19b. FIG. 10 shows actual measurement results measured using a commercially available laser displacement meter. As shown in FIG. 4, only one peak is observed. When the peak is not observed, the external distance measuring unit 19 is brought closer to the inner surface, or the external distance measuring unit 19 is tilted to change the emission direction of the laser light to search for the position and angle at which the peak is observed. Is preferred.

  The present inventors consider that it is essential to acquire data of the three-dimensional shape of the inner surface of the crucible and the three-dimensional distribution of the thickness of the transparent layer in order to improve the performance and quality control of the crucible. However, since the crucible is a transparent body, it is difficult to optically measure the three-dimensional shape. I tried to illuminate the inner surface of the crucible to acquire an image and analyze the image, but this method takes a very long time to analyze the image. It could not be used to measure the shape.

  In such a situation, the present inventors irradiated the laser beam from the oblique direction to the inner surface of the crucible, and in addition to the reflected light (inner surface reflected light) from the inner surface of the crucible, the transparent layer and the bubbles It was found that reflected light from the interface of the containing layer (interface reflected light) can also be detected. The interface between the transparent layer and the bubble-containing layer is a surface where the bubble content changes rapidly, but is not a clear interface such as the interface between air and glass. It was a surprising discovery that is detectable. And the apparatus which assists the setting of the manufacturing conditions of the silica glass crucible of said embodiment became possible only after development of the three-dimensional shape measuring apparatus of such a silica glass crucible.

<Characteristic values associated with three-dimensional shape of silica glass crucible>
The design data, the simulation data, and the measurement data may all include characteristic value data associated with the three-dimensional shape of the silica glass crucible. As this characteristic value, for example, one or more characteristic values selected from bubble content, surface roughness, infrared absorption spectrum, and Raman spectrum can be suitably used.

  In this case, the coincidence degree determination unit 114 is configured to also determine the coincidence degree of the characteristic values included in two of the design data, the simulation data, and the measurement data. Then, the improved physical property parameter setting unit 402, when either the simulation data obtained based on the initial physical property parameters and the degree of coincidence of the measurement data or the characteristic value is below a predetermined level, The improved physical property parameter is set so that the degree of coincidence between the three-dimensional shape and the characteristic value is not less than a predetermined level. The improved manufacturing condition setting unit 308 is configured to set manufacturing conditions for obtaining simulation data in which the degree of coincidence between the three-dimensional shape and the characteristic value with the design data is equal to or higher than a predetermined level.

  Thus, in addition to the three-dimensional shape, by taking into consideration the characteristic values such as the bubble content, surface roughness, infrared absorption spectrum, and Raman spectrum, the simulation accuracy can be further enhanced. As a result, a silica glass crucible having a higher degree of coincidence of the three-dimensional shape with the design data can be manufactured by the rotational mold method.

<Method for determining the three-dimensional distribution of the bubble distribution in the crucible>
After the three-dimensional shape of the inner surface of the crucible is obtained, the bubble distribution is measured by measuring the bubble distribution at the crucible wall at the position corresponding to each measurement point at a plurality of measurement points on the three-dimensional shape. Determine the three-dimensional distribution. The method of measuring the bubble distribution at the crucible wall at each measurement point is not particularly limited as long as it is a non-contact type, but a confocal microscope that can selectively acquire information from the focused surface is used. In this case, a clear image that clearly shows the position of the bubble can be acquired, so that highly accurate measurement is possible. Further, by acquiring and synthesizing an image on the surface of each focal position while shifting the focal position, the three-dimensional arrangement of the bubbles can be understood and the size of each bubble can be known, so that the bubble distribution can be obtained. Methods for moving the focal position include (1) moving the crucible, (2) moving the probe, and (3) moving the objective lens of the probe.

  The arrangement of the measurement points is not particularly limited. For example, the measurement points are arranged at intervals of 5 to 20 mm in the direction from the opening to the bottom of the crucible, and at intervals of 10 to 60 degrees in the circumferential direction, for example. Specifically, for example, a confocal microscope probe is attached to the tip of the internal robot arm 5 and moved along the inner surface in a non-contact manner in the same manner as the internal distance measuring unit 17. When the internal distance measuring unit 17 is moved, only the rough three-dimensional shape of the inner surface is known, but the exact three-dimensional shape of the inner surface is not known. Therefore, based on the rough three-dimensional shape. Although the internal distance measuring unit 17 has been moved, since the accurate three-dimensional shape of the inner surface is known when measuring the bubble distribution, the distance between the inner surface and the probe when moving the confocal microscope probe is measured. Can be controlled with high accuracy.

  After the confocal microscope probe is moved from the opening to the bottom of the crucible and the bubble distribution is measured at a plurality of points on the movement path, the turntable 9 is rotated to change the bubble distribution in another part of the crucible 11. Measure. With such a method, the bubble distribution can be measured over the entire inner surface of the crucible, and the three-dimensional distribution of the crucible bubble distribution can be determined based on the measurement result.

<Method of determining the three-dimensional distribution of the surface roughness of the inner surface of the crucible>
After the three-dimensional shape of the inner surface of the crucible is obtained, the three-dimensional distribution is determined by measuring the surface roughness of the inner surface at a plurality of measurement points on the three-dimensional shape. The method for measuring the surface roughness at each measurement point is not particularly limited as long as it is a non-contact type, but it is highly accurate if a confocal microscope that can selectively acquire information from the focused surface is used. Measurement is possible. Further, if a confocal microscope is used, information on the detailed three-dimensional structure of the surface can be acquired, and the surface roughness can be obtained using this information. The surface roughness includes a center line average roughness Ra, a maximum height Rmax, and a ten-point average height Rz. Any of these may be adopted, and another parameter reflecting the surface roughness is adopted. May be. The arrangement of measurement points and the specific measurement method are the same as those in the above-described method for determining the three-dimensional distribution of the bubble distribution of the crucible.

<Method for determining the three-dimensional distribution of the infrared absorption spectrum of the inner surface of the crucible>
After the three-dimensional shape of the inner surface of the crucible is obtained, the three-dimensional distribution is determined by measuring the infrared absorption spectrum of the inner surface at a plurality of measurement points on the three-dimensional shape. The method of measuring the infrared absorption spectrum at each measurement point is not particularly limited as long as it is a non-contact type, but the reflected light is detected by irradiating infrared rays toward the inner surface. It can be measured by obtaining the spectral difference. The arrangement of measurement points and the specific measurement method are the same as those in the above-described method for determining the three-dimensional distribution of the bubble distribution of the crucible. The arrangement of measurement points and the specific measurement method are the same as those in the above-described method for determining the three-dimensional distribution of the bubble distribution of the crucible.

<Method of determining the three-dimensional distribution of the Raman spectrum of the inner surface of the crucible>
After the three-dimensional shape of the inner surface of the crucible is obtained, the three-dimensional distribution is determined by measuring the Raman spectrum of the inner surface at a plurality of measurement points on the three-dimensional shape. The method of measuring the Raman spectrum at each measurement point is not particularly limited as long as it is a non-contact type, but it can be measured by irradiating a laser beam toward the inner surface and detecting the Raman scattered light. The arrangement of measurement points and the specific measurement method are the same as those in the above-described method for determining the three-dimensional distribution of the bubble distribution of the crucible.

Claims (2)

An apparatus for supporting the setting of manufacturing conditions for a silica glass crucible,
A design data acquisition unit for acquiring design data of the three-dimensional shape of the silica glass crucible of any model, production lot or serial number;
A production condition data setting unit for setting production condition data in a rotational molding method of the silica glass crucible based on the design data;
A simulation unit that obtains simulation data of a three-dimensional shape of a silica glass crucible obtained by the manufacturing conditions using a calculation engine capable of one or more calculations selected from the group consisting of heat transfer calculation, fluid calculation and structure calculation; ,
A physical property parameter setting unit for setting physical property parameters used by the calculation engine;
A measurement data acquisition unit that acquires measurement data of a three-dimensional shape of a silica glass crucible manufactured by a rotational mold method based on the manufacturing conditions;
The design data, the simulation data, and two types of data among the measurement data are compared and contrasted, and a degree of coincidence determination unit for determining the degree of coincidence between the three-dimensional shapes,
An output unit of the simulation data or manufacturing condition data;
With
The physical property parameter setting unit, when the degree of coincidence of the three-dimensional shape of the simulation data and the measurement data obtained based on the initial physical property parameter is below a predetermined level, the degree of coincidence is a predetermined level It has an improved physical property parameter setting unit for setting the improved physical property parameters as described above,
The manufacturing condition data setting unit has an improved manufacturing condition data setting unit for setting manufacturing conditions in a rotational mold method for obtaining simulation data having a degree of coincidence with the design data of a predetermined level or more.
apparatus. The improved manufacturing condition data setting unit
An arc discharge condition setting unit for setting an arc power condition when arc melting the silica powder layer deposited in the mold by the rotary mold method;
A decompression condition setting unit for setting a decompression condition when decompressing the silica powder layer from the mold side;
The rotation number setting part which sets the rotation speed of the said mold is included, The apparatus of Claim 1.