JP7792835B2 - Melt molding device and method for manufacturing oscillator - Google Patents

Description

This specification relates to a melt-molding device for vibrators and a manufacturing method thereof.

Patent Document 1 discloses a Bird-bath Resonator Gyroscope (BRG), which uses fused silica as a vibrator, as a gyro capable of achieving high accuracy. Specifically, a fusion molding die is prepared with a hole formed in part of its top surface. The hole is formed in part of the top surface, centered on a central axis perpendicular to the top surface of the mold. A workpiece (e.g., a quartz plate) is placed so as to cover the hole, and the top surface of the workpiece is heated with a burner. A hemispherical vibrator can be created by melting and deforming the workpiece so that it fills the hole.

US Patent Application Publication No. 2018/079129

To create a vibrator with high symmetry around the central axis of the hole, it is necessary to heat it circularly symmetrically around the central axis of the hole. This requires axial alignment to align the central axis of the burner flame with the central axis of the hole. However, axial alignment is time-consuming and labor-intensive, which increases the time required to create the vibrator.

The melt-forming apparatus disclosed in this specification includes a stage with a flat support surface. The melt-forming apparatus includes a control unit that controls the planar position of the support surface of the stage. The melt-forming apparatus is arranged on the support surface and includes a melt-forming mold that has a flat upper surface and a hole formed in part of the upper surface centered on a central axis perpendicular to the upper surface. The melt-forming apparatus includes a burner that is arranged above the central axis facing the hole and is configured to generate a flame toward the hole. The melt-forming apparatus includes a temperature sensor that measures the temperature of the melt-forming mold. The temperature sensor is configured to be able to measure temperatures at three or more measurement points that are arranged rotationally symmetrically around the central axis. The control unit is configured to be able to perform planar position adjustment control that controls the planar position of the stage so that the temperature difference between the measured temperatures at the three or more measurement points is small.

In the above configuration, the temperature is measured at three or more measurement points arranged rotationally symmetrically around the central axis. The planar position of the stage is then controlled so that the temperature difference between the measured temperatures at the three or more measurement points is minimized. This allows for automatic alignment of the central axis of the burner flame with the central axis of the hole. This reduces the effort and time required for the alignment process, thereby shortening the time required to manufacture the vibrator.

The burner may be configured to be movable in the vertical direction along the central axis. The control unit may execute planar position adjustment control when the distance between the burner and the hole is a first distance. After executing planar position adjustment control, the control unit may be configured to lower the burner so that the distance between the burner and the hole is a second distance that is smaller than the first distance. Details of the effects will be explained in the examples.

The temperature sensor may be a contact-type temperature sensor. The temperature sensor may be positioned so that it is exposed on the top surface at each of three or more measurement points. Details of the effects will be explained in the examples.

The temperature sensor may be a contact-type temperature sensor. The temperature sensor may be positioned at each of three or more measurement points so that it is not exposed on the upper surface. Details of the effects will be explained in the examples.

The temperature sensor may be a non-contact temperature sensor. The temperature sensors may be positioned above the top surface at positions corresponding to each of three or more measurement points. Details of the effects will be explained in the examples.

The temperature sensor may be a single non-contact temperature sensor. The temperature sensor may be configured to scan a circumference centered on a central axis and including three or more measurement points. Details of the effects will be explained in the examples.

The melt-forming mold may further include a wall surrounding the outer periphery. The upper end of the wall may be located above the upper surface of the melt-forming mold. Details of the effects will be explained in the examples.

The device may further include a heat sink positioned between the stage and the melt-molding mold and configured to maintain a constant temperature. Details of the effects will be explained in the examples.

One embodiment of a method for manufacturing a vibrator disclosed herein is a method for manufacturing a vibrator using a melt molding apparatus including: a stage with a flat mounting surface; a control unit for controlling the planar position of the mounting surface of the stage; a melt molding mold disposed on the mounting surface and having a flat upper surface and a hole formed in a portion of the upper surface centered on a central axis perpendicular to the upper surface; a burner disposed above the central axis facing the hole, configured to generate a flame toward the hole and configured to be movable up and down along the central axis; and a temperature sensor for measuring the temperature of the melt molding mold, configured to measure temperatures at three or more measurement points arranged rotationally symmetrically about the central axis. The method for manufacturing a vibrator includes a placement step of placing a plate-shaped workpiece material on the upper surface so as to cover the hole. The method for manufacturing a vibrator includes a step of generating a flame in the burner while the distance between the burner and the hole is a first distance. The method for manufacturing a vibrator includes a planar position adjustment step of controlling the planar position of the stage so as to reduce the temperature difference between the three or more measurement points while maintaining the first distance. The vibrator manufacturing method includes a step of lowering the burner when the temperature difference becomes smaller than a predetermined specific temperature difference, so that the distance between the burner and the hole becomes a second distance that is smaller than the first distance. The vibrator manufacturing method also includes a heating step of heating the top surface of the workpiece with a flame while maintaining the second distance. Details of the effects will be explained in the examples.

During the heating process, the position of the stage in the planar direction may be controlled so that the temperature difference between the measured temperatures at three or more measurement points is reduced. Details of this effect will be explained in the examples.

During the heating process, the burner may be raised so that the distance between the burner and the hole is equal to or greater than the first distance when the measured temperatures at each of the three or more measurement points reach a predetermined temperature. Details of this effect will be explained in the examples.

During the heating process, if the measured temperature at at least one of the three or more measurement points exceeds a predetermined upper limit temperature, the burner may be raised so that the distance between the burner and the hole is equal to or greater than the first distance. Details of this effect will be explained in the examples.

1 is a schematic cross-sectional view of a melt-molding apparatus 1 of Example 1. FIG. 1 is a top view of a melt-molding apparatus 1 according to a first embodiment. FIG. FIG. 10 is a flow chart illustrating a manufacturing process of a vibrator. FIG. 2 is an enlarged schematic cross-sectional view of the vicinity of a hole 20h. FIG. 2 is an enlarged schematic cross-sectional view of the vicinity of a hole 20h. FIG. 10 is a schematic cross-sectional view of a melt-molding apparatus 201 according to a second embodiment. FIG. 10 is a top view of a melt-molding apparatus 201 according to a second embodiment. FIG. 10 is a top view of a melt-molding apparatus 301 according to a third embodiment.

Figure 1 shows a schematic cross-sectional view of the melt-forming device 1. Figure 2 shows a top view of the melt-forming device 1. Figure 1 corresponds to the cross-sectional view taken along line I-I in Figure 2. Note that the burner 50 and motorized stage 45 are omitted from Figure 2.

The motorized stage 45 is configured to be movable in the x and y directions (horizontal direction). The motorized stage 45 has a flat mounting surface 45s. The molding die 20 is placed on the mounting surface 45s via the heat sink 40 and plate 10.

The heat sink 40 is positioned between the motorized stage 45 and the forming mold 20. The heat sink 40 is in contact with the underside 10r of the plate 10. A circulation pipe 41 is arranged inside the heat sink 40. The circulation pipe 41 is connected to a chiller unit 42. A heat medium kept at a constant temperature above room temperature (e.g., 40°C) by the chiller unit 42 circulates through the circulation pipe 41. This allows the heat sink 40 to maintain a constant temperature during the process.

The plate 10 is placed on the heat sink 40. The plate 10 is a stainless steel base on which the forming mold 20 is placed. The plate 10 has the function of cooling the forming mold 20. A first communication hole 10c1 is formed in the surface 10s of the plate 10. The first communication hole 10c1 is located at a position corresponding to the through hole 20e and is connected to the through hole 20e. The first communication hole 10c1 is connected to the negative pressure generating means 81 via the first communication path 10p1. The negative pressure generating means 81 is a means capable of generating negative pressure in the hole portion 20h. The negative pressure generating means 81 may be, for example, a vacuum pump.

The forming die 20 is disposed on the surface 10s of the plate 10. The forming die 20 is a die for melting and deforming the quartz plate 30 to form a hemispherical vibrator. The material of the forming die 20 is graphite. In this embodiment, the forming die 20 is disk-shaped with a central axis CA. The forming die 20 has a lower surface 20r, an upper surface 20s, a hole 20h, a support 20p, and a through-hole 20e. The lower surface 20r and the upper surface 20s are flat surfaces perpendicular to the central axis CA. A hole 20h is formed in part of the upper surface 20s. The hole 20h is a deformation space for the quartz plate 30 to melt and deform. In this embodiment, the hole 20h has a cylindrical shape hollowed out around the central axis CA. The hole 20h has a bottom surface 20b. A support pillar 20p is disposed in the center of the hole 20h, extending vertically upward from the bottom surface 20b. The support pillar 20p is a cylinder with a central axis CA. The bottom surface 20b has multiple through holes 20e formed therein, penetrating to the lower surface 20r. The through holes 20e communicate with the first communication hole 10c1.

Grooves 21-23 are formed on the upper surface 20s. Grooves 21-23 are formed radially from the central axis CA. Grooves 21-23 are arranged with 120° rotational symmetry about the central axis CA. The inner tips of grooves 21-23 are located on a circumference CR centered on the central axis CA. The circumference CR is a concentric circle that surrounds the outer periphery of hole 20h. The radius of circumference CR is greater than the radius of hole 20h.

Thermocouples 61-63 are arranged inside grooves 21-23 so as to be exposed on the top surface 20s. Thermocouples 61-63 are contact-type temperature sensors. In this example, type B thermocouples are used. The height in the z direction of thermocouples 61-63 is smaller than the depth in the z direction of grooves 21-23. Therefore, thermocouples 61-63 do not protrude above the top surface 20s.

Measurement points 61m-63m are located at the tips of thermocouples 61-63. Thermocouples 61-63 measure the temperature of the forming mold 20 at measurement points 61m-63m. Measurement points 61m-63m are located on the circumference CR. In other words, measurement points 61m-63m are arranged with 120° rotational symmetry around central axis CA. Furthermore, rear ends 61e-63e of thermocouples 61-63 are connected to control unit 70 by wiring (not shown).

A quartz plate 30 is placed on the upper surface 20s of the mold 20 so as to cover the hole 20h. The quartz plate 30 is the material to be processed to form the vibrator. The quartz plate 30 is made of fused silica. The thickness of the quartz plate 30 is, for example, 100 μm or less. In this embodiment, the quartz plate 30 is square, but it may also be circular or regular hexagonal.

The burner 50 is positioned above the central axis CA, facing the hole 20h. The burner 50 heats the quartz plate 30 by generating a flame toward the hole 20h. The burner 50 is fixed to a movable mechanism 53 that moves in the vertical direction (±z direction). This allows the burner 50 to move up and down along the central axis CA. The burner 50 is equipped with a premixing chamber 50c. Fuel gas G1 (e.g., propane) and oxygen gas G2 are supplied to the premixing chamber 50c from a gas flow regulator 52. The gas flow regulator 52 is equipped with a mass flow controller (not shown), and is capable of controlling and monitoring the flow rates of the fuel gas G1 and oxygen gas G2.

The partition 11 is arranged on the surface 10s of the plate 10 so as to surround the outer periphery of the forming mold 20. The partition 11 is a cylindrical wall made of stainless steel. The upper end 11u of the partition 11 is located above (in the +z direction) the upper surface 20s of the forming mold 20. This blocks external disturbances to the airflow, making it possible to suppress flame fluctuations. The temperature distribution of the quartz plate 30 heated by the flame can be made point-symmetrical about the central axis CA, making it possible to reproducibly manufacture highly symmetrical glass vibrators. Furthermore, the partition 11 does not come into contact with the forming mold 20. This prevents the partition 11 from functioning as a fin to cool the forming mold 20.

The control unit 70 is connected to the motorized stage 45, the movable mechanism 53, the gas flow regulator 52, the thermocouples 61-63, and the negative pressure generating means 81. The control unit 70 acquires various information from these devices and controls them. The control unit 70 may be, for example, a PC.

(Vibrator manufacturing process)
The manufacturing process of the vibrator will be described using the flow diagram of Fig. 3. In step S10, the forming die 20 is placed on the surface 10s of the plate 10. A heat medium is constantly circulated from the chiller equipment 42 through the circulation pipe 41 to keep the heat sink 40 at a constant temperature.

In step S20, the quartz plate 30 is placed on the upper surface 20s of the forming mold 20. At this time, it is positioned so that the central axis CA and the center of the quartz plate 30 coincide. In response to a signal from the control unit 70, the negative pressure generating means 81 evacuates the first communication hole 10c1 at a pressure of -75 kPa. This also evacuates the hole portion 20h via the through hole 20e, and the quartz plate 30 is adsorbed and fixed to the upper surface 20s of the forming mold 20. In addition, a partition 11 is placed on the surface 10s of the plate 10. This results in the state shown in Figures 1 and 2.

In step S30, the control unit 70 begins measuring the temperatures at measurement points 61m to 63m using thermocouples 61 to 63. In step S40, the control unit 70 ignites the burner 50. Ignition is performed when the tip 50s of the burner 50 is in a retracted position where it is sufficiently separated from the surface of the quartz plate 30. Specifically, in response to a signal from the control unit 70, the gas flow regulator 52 adjusts the fuel gas G1 to a flow rate of 200 sccm and supplies it to the burner 50 for ignition. After ignition, the flow rates of the fuel gas G1 and oxygen gas G2 are adjusted to 1000 sccm and 5000 sccm, respectively, and these are supplied to the burner 50 to generate a flame.

In step S50, the movable mechanism 53 lowers the burner at a speed of 50 mm/s in response to a signal from the control unit 70. The lowering stops when the distance between the tip 50s and the upper surface of the support 20p decreases to the first distance L1. The first distance L1 is the distance at which the quartz plate 30 is not deformed by the flame FL. This results in the state shown in Figure 4.

In step S60, the control unit 70 adjusts the position of the motorized stage 45 in the xy plane so as to reduce the temperature difference between the measured temperatures at measurement points 61m to 63m. This adjustment is performed while maintaining the first distance L1. Specifically, the control unit 70 calculates the amount of movement in the x and y directions to keep the temperatures at measurement points 61m to 63m within a specific temperature difference (e.g., ±5°C). The calculation result is sent to the motorized stage 45, which is then moved in the xy plane. This feedback control enables automatic axial alignment control to align the central axis CA of the support 20p with the flame central axis FA (see Figure 4).

There are various methods for detecting the completion of axis alignment control. In this embodiment, axis alignment is determined to be complete by detecting that the measured temperatures at measurement points 61m to 63m remain within a specific temperature difference (e.g., ±5°C) for a predetermined time (e.g., 3 seconds). Once axis alignment control is complete, proceed to step S70.

In step S70, the movable mechanism 53 lowers the burner 50 at a speed of 10 mm/s in response to a signal from the control unit 70. The lowering stops when the distance between the tip 50s and the upper surface of the support 20p decreases to the second distance L2 (see Figure 5). The second distance L2 is shorter than the first distance L1. This starts the heating process of the quartz plate 30 by the flame FL.

Even during the heating process of step S70, the position of the motorized stage 45 in the xy plane is adjusted so that the temperature difference between the measurement points 61m to 63m is reduced. This allows the central axis CA of the support 20p to remain aligned with the central axis FA of the flame. Furthermore, highly symmetrical glass vibrators can be manufactured with good reproducibility.

In step S80 during the heating process, the control unit 70 determines whether the melting and deformation of the quartz plate 30 has been completed. Specifically, it determines whether the measured temperatures at each of the measurement points 61m-63m have reached a predetermined temperature. The measured temperatures at the measurement points 61m-63m indicate a temperature corresponding to the temperature of the quartz plate 30 above the hole 20h. Therefore, by measuring the temperatures at the measurement points 61m-63m, it is possible to indirectly measure the temperature of the quartz plate 30 above the hole 20h. In this embodiment, the predetermined temperature is set to a temperature indicating that the quartz plate 30 above the hole 20h has been heated to its softening temperature.

If a negative judgment is made in step S80 (S80: NO), the process proceeds to step S90. In step S90 during the heating process, the control unit 70 determines whether the measured temperature at at least one of measurement points 61m-63m exceeds a predetermined upper limit temperature. The upper limit temperature is a temperature higher than the specified temperature detected in step S80. If a negative judgment is made (S90: NO), the process returns to step S80 and the heating process continues. On the other hand, if a positive judgment is made (S90: YES), the control unit 70 determines that an abnormality has occurred and proceeds to step S100. In step S100, the control unit 70 raises the movable mechanism 53 so that the distance between the burner 50 and the support 20p is equal to or greater than the first distance L1. The effect is explained below. If the temperature of the quartz plate 30 rises too high, exceeding its softening temperature, it will melt and break. This exposes the forming mold 20 to flames, causing it to burn and change shape. It will be possible to prevent such situations.

If it is determined in step S80 that the melting and deformation of the quartz plate 30 is complete (S80: YES), the quartz plate 30 is melted and deformed into the desired shape, as shown in FIG. 5. Then, the process proceeds to step S100. In step S100, the movable mechanism 53 raises the burner 50 at a speed of 50 mm/s in response to a signal from the control unit 70. The rise then stops when the burner 50 reaches the retracted position. The flame is also extinguished.

In step S110, the control unit 70 waits for the cooling to be completed. Specifically, upon detecting that the measured temperatures at measurement points 61m to 63m have dropped below a predetermined cooling temperature (e.g., 50°C), the control unit 70 stops the negative pressure generating means 81. This opens the hole 20h to the atmosphere.

In step S120, the fused and molded quartz plate 30 is removed from the mold 20. The unmolded area on the periphery of the quartz plate 30 is removed using a method such as CMP, thereby completing the vibrator.

In parallel with the flow shown in Figure 3, the gas flow regulator 52 monitors the gas flow rate. Specifically, from ignition of the burner 50 (step S40) to extinguishing (step S100), the gas flow regulator 52 monitors the flow rates of the fuel gas G1 and oxygen gas G2. If the flow rates deviate from the desired range, the gas flow regulator 52 transmits an abnormality signal to the control unit 70 to notify the occurrence of an abnormality. In response to receiving the abnormality signal, the control unit 70 immediately raises the movable mechanism 53 and extinguishes the burner 50. The effect is as follows: If the flow rates of the fuel gas G1 and/or oxygen gas G2 deviate from the desired range, the flame temperature will fluctuate beyond the allowable range. If glass vibrators are manufactured under these conditions, the shape will not be reproducible, resulting in a large number of defective products. This type of situation can be prevented.

In parallel with the flow of Figure 3, the chiller equipment 42 monitors whether the temperature of the heat medium is being maintained within the desired range. If the temperature of the heat medium deviates from the desired range, the chiller equipment 42 sends an abnormality signal to the control unit 70 to notify the occurrence of an abnormality. In response to receiving the abnormality signal, the control unit 70 raises the movable mechanism 53 and extinguishes the burner 50. Explain the effect: If the temperature of the heat medium deviates from the desired range, the amount of heat exhausted from the flame-heated molding die 20 to the plate 10 will fluctuate beyond the allowable range. If glass vibrators are manufactured under these conditions, the shape will not be reproducible, resulting in a large number of defective products. It is possible to prevent such situations.

(effect)
To fabricate a resonator with high symmetry with respect to the central axis CA of the hole 20h, it is necessary to heat the resonator with circular symmetry about the central axis CA. Therefore, an axial alignment process is required to align the burner flame central axis FA with the central axis CA of the hole 20h. Conventional axial alignment processes involve fabricating a resonator (Bird-bath Resonator; BR) made of fused silica and confirming the symmetry of the completed resonator. The position of the motorized stage 45 in the x-y plane is then fine-tuned based on the confirmed symmetry. This process is repeated until a highly symmetrical resonator is fabricated, requiring a great deal of time and effort. In contrast, the technology described herein is configured to measure the flame temperature at measurement points 61m to 63m, which are rotationally symmetrically positioned around the central axis CA of the hole 20h. The position of the motorized stage 45 in the x-y plane is then controlled to minimize the temperature difference between the measurement points 61m to 63m. This allows automatic alignment of the flame central axis FA of the burner 50 with the central axis CA of the hole 20h. This reduces the effort and time required for the alignment, thereby shortening the time required to manufacture the vibrator.

When vibrators are mass-produced, the nozzle shape of the tip 50s of the burner 50 can change in a high-temperature environment, causing the position of the flame center axis FA and temperature distribution to change over time. Conventionally, vibrators are continuously manufactured after the axial alignment process is completed. As the number of vibrators manufactured increases, the symmetry of the vibrator shape is lost, making it difficult to achieve reproducibility of the shape and dimensions. In contrast, with the technology described herein, the axial alignment process (step S60) is performed every time before the quartz plate 30 heating process (step S70). This makes it possible to fine-tune the axial alignment in response to changes in the nozzle shape of the tip 50s over time. This makes it possible to improve the reproducibility of the shape and dimensions.

The temperature of the metal plate 10 on which the forming mold 20 is placed is affected by room temperature. Therefore, heat transfer (exhaust heat) from the flame-heated forming mold 20 to the plate 10 varies depending on the time of day and the season. This has traditionally made it difficult to improve the reproducibility of the shape and dimensions of vibrators. However, the technology described herein is equipped with a heat sink 40 that is kept at a constant temperature by a chiller system 42. The heat sink 40 is then placed in contact with the underside 10r of the plate 10. This improves the reproducibility of heat transfer (exhaust heat) from the flame-heated forming mold 20 to the plate 10. It is now possible to manufacture highly symmetrical vibrators with good reproducibility throughout the year.

Figure 6 shows a schematic cross-sectional view of the melt-molding apparatus 201 of Example 2. Figure 7 shows a top view of the melt-molding apparatus 201 of Example 2. Figure 6 corresponds to the cross-sectional view taken along line VI-VI in Figure 7. Example 2 differs from Example 1 in that the thermocouples 61-63 are positioned so that they are not exposed on the upper surface 20s of the mold 20. Components that are common to the melt-molding apparatus 1 of Example 1 are given the same reference numerals, and descriptions thereof will be omitted. Additionally, components unique to Example 2 are distinguished by being given reference numerals in the 200s.

Tunnels 221-223 are formed in the forming die 20. The longitudinal axes of the tunnels 221-223 are parallel to the top surface 20s. The tunnels 221-223 are formed radially from the central axis CA. The tunnels 221-223 are arranged with 120° rotational symmetry about the central axis CA. The inner peripheral tips of the tunnels 221-223 are located on a circumference CR centered on the central axis CA. Entrances 221a-223a of the tunnels 221-223 are formed on the outer peripheral side surface of the forming die 20.

Thermocouples 61-63 are inserted into tunnels 221-223 from entrances 221a-223a. Measurement points 61m-63m are located at the tips of thermocouples 61-63. Thermocouples 61-63 measure the temperature of the forming mold 20 at measurement points 61m-63m. Measurement points 61m-63m are arranged with 120° rotational symmetry around central axis CA.

(effect)
By providing a configuration in which thermocouples 61-63 are inserted into tunnels 221-223, there is no need to form grooves in the upper surface 20s of mold 20 for arranging thermocouples 61-63. Compared to when grooves are provided, the contact area between upper surface 20s of mold 20 and quartz plate 30 can be increased, making it possible to stabilize suction when hole 20h is under negative pressure. Furthermore, because the symmetry of heat transfer (heat exhaust) from quartz plate 30 to mold 20 is no longer hindered by grooves, it becomes possible to manufacture highly symmetrical vibrators with good reproducibility.

Figure 8 shows a top view of the melt molding apparatus 301 of Example 3. Example 3 differs from Example 1 in that radiation thermometers 361-363 are used instead of thermocouples 61-63. Components that are common to the melt molding apparatus 1 of Example 1 are given the same reference numerals, and descriptions thereof will be omitted. Additionally, components unique to Example 3 are distinguished by being given reference numerals in the 300 range.

Radiation thermometers 361-363 are non-contact temperature sensors. Radiation thermometers 361-363 are positioned by a fixing mechanism (not shown) at positions corresponding to measurement points 61m-63m, respectively, and above the upper surface 20s. The focal points of radiation thermometers 361-363 are aligned with measurement points 61m-63m. Radiation thermometers 361-363 pass through the transparent quartz plate 30 and are focused on the upper surface 20s of the mold 20. This allows the temperature of the upper surface 20s at measurement points 61m-63m to be measured non-contact. This makes it possible to indirectly measure the temperature of the quartz plate 30.

(effect)
There is no need for the forming die 20 to have grooves or tunnels for placing thermocouples, which makes it possible to reduce the cost and time required to manufacture the forming die 20. Furthermore, since the symmetry of heat transfer (exhaust heat) from the quartz plate 30 to the forming die 20 is not hindered by grooves or tunnels, it becomes possible to manufacture highly symmetrical vibrators with good reproducibility.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples given above.

(Modification)
The radiation thermometer arrangement and measurement mode of the third embodiment may be various. For example, a configuration including only one radiation thermometer 361 may be used. The configuration may be configured to be capable of scanning the focal point on a circumference CR including measurement points 61m to 63m. Such scanning can be achieved, for example, by providing a mechanism for moving the radiation thermometer 361 along a circumferential path CP (see FIG. 8) centered on the central axis CA. This makes it possible to increase the number of measurement points while reducing the number of radiation thermometers.

The method for determining the completion of melting and deformation of the quartz plate 30 is not limited to measuring the temperature at measurement points 61m to 63m (step S80), and various other methods may be used. For example, the completion of melting and deformation may be determined when a predetermined time has elapsed since the heating process began.

It may also be configured without a partition 11.

The material of the mold 20 is not limited to graphite. Various materials, such as boron nitride, can be used as long as they have the required thermal shock resistance and thermal conductivity.

The material of the vibrator is not limited to fused silica. Any dielectric material that melts and deforms can be used.

Furthermore, the technical elements described in this specification or drawings may exhibit technical utility either alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated in this specification or drawings may achieve multiple objectives simultaneously, and achieving any one of those objectives is itself technically useful.

1: Melt-molding device 10: Plate 20: Mold 20h: Hole 20p: Support 30: Quartz plate 45: Electric stage 50: Burner 61-63: Thermocouples 61m-63m: Measurement points 70: Control unit 81: Negative pressure generating means

Claims (16)

A melt molding apparatus,
a stage having a flat mounting surface;
a control unit for controlling a position of the stage in a planar direction of the mounting surface;
a melt-forming mold disposed on the mounting surface and including a flat upper surface and a hole formed in a part of the upper surface with a central axis perpendicular to the upper surface as a center;
a burner disposed above the central axis and facing the hole, the burner being configured to generate a flame toward the hole;
a temperature sensor for measuring the temperature of the melt-molding mold, the temperature sensor being configured to be able to measure temperatures at three or more measurement points arranged rotationally symmetrically around the central axis; and
Equipped with
the control unit is configured to be able to perform planar position adjustment control for controlling the position of the stage in the planar direction so as to reduce a temperature difference between the measured temperatures among the three or more measurement points.
Melt molding equipment. The burner is configured to be movable in a vertical direction along the central axis,
the control unit executes the planar position adjustment control in a state where a distance between the burner and the hole is a first distance,
The melt molding device according to claim 1, wherein the control unit is configured to be able to lower the burner after executing the planar position adjustment control so that the distance between the burner and the hole becomes a second distance that is smaller than the first distance. the temperature sensor is a contact-type temperature sensor,
The melt-molding apparatus according to claim 1 or 2, wherein each of the three or more measurement points is arranged so as to be exposed on the upper surface. the temperature sensor is a contact-type temperature sensor,
The melt-molding apparatus according to claim 1 or 2, wherein each of the three or more measurement points is arranged so as not to be exposed from the upper surface. the temperature sensor is a non-contact temperature sensor,
The melt-molding device according to claim 1 or 2, wherein the measuring points are disposed at positions corresponding to the three or more measurement points and above the upper surface. the temperature sensor is a non-contact temperature sensor;
The melt-molding device according to claim 1 or 2, configured to be capable of scanning a circumference centered on the central axis and including three or more of the measurement points. Further provided is a wall portion surrounding the outer periphery of the melt-forming mold,
7. The melt-forming device according to claim 1, wherein an upper end of the wall portion is located above the upper surface of the melt-forming mold. a heat sink disposed between the stage and the melt-molding mold and configured to be able to maintain a constant temperature;
The melt-molding apparatus according to any one of claims 1 to 7. a stage having a flat mounting surface;
a control unit for controlling a position of the stage in a planar direction of the mounting surface;
a melt-forming mold disposed on the mounting surface and including a flat upper surface and a hole formed in a part of the upper surface with a central axis perpendicular to the upper surface as a center;
a burner disposed above the central axis and facing the hole, configured to be capable of generating a flame toward the hole, and configured to be movable in a vertical direction along the central axis;
a temperature sensor for measuring the temperature of the melt-molding mold, the temperature sensor being configured to be able to measure temperatures at three or more measurement points arranged rotationally symmetrically around the central axis; and
A method for manufacturing a vibrator using a melt molding apparatus comprising:
a placement step of placing a plate-shaped workpiece on the upper surface so as to cover the hole;
generating a flame in the burner while the distance between the burner and the hole is a first distance;
a planar position adjusting step of controlling a position of the stage in the planar direction while maintaining the first distance so that a temperature difference between the measured temperatures among the three or more measurement points becomes small;
a step of lowering the burner so that the distance between the burner and the hole becomes a second distance that is smaller than the first distance in response to the temperature difference becoming smaller than a predetermined specific temperature difference;
a heating step of heating the upper surface of the workpiece with the flame while maintaining the second distance;
A method for manufacturing a vibrator, comprising: The method for manufacturing a vibrator described in claim 9, wherein the position of the stage in the planar direction is controlled during the heating process so that the temperature difference between the measured temperatures at three or more of the measurement points is reduced. The method for manufacturing a vibrator described in claim 9 or 10, wherein, in the heating step, the burner is raised so that the distance between the burner and the hole becomes equal to or greater than the first distance when the measured temperatures at each of the three or more measurement points reach a predetermined temperature. A method for manufacturing a vibrator according to any one of claims 9 to 11, wherein, during the heating process, the burner is raised so that the distance between the burner and the hole is equal to or greater than the first distance when the measured temperature of at least one of the three or more measurement points exceeds a predetermined upper limit temperature. the temperature sensor is a contact-type temperature sensor,
The method for manufacturing a vibrator according to any one of claims 9 to 12, wherein each of the three or more measurement points is arranged so as to be exposed on the upper surface. the temperature sensor is a contact-type temperature sensor,
13. The method for manufacturing a vibrator according to claim 9, wherein each of the three or more measurement points is arranged so as not to be exposed on the upper surface. the temperature sensor is a non-contact temperature sensor,
The method for manufacturing a vibrator according to any one of claims 9 to 12, wherein the measurement points are arranged at positions corresponding to the three or more measurement points and above the upper surface. the temperature sensor is a non-contact temperature sensor;
The method for manufacturing a vibrator according to any one of claims 9 to 12, wherein the method is configured to be able to scan a circumference centered on the central axis and including three or more of the measurement points.