Melt molding apparatus

Abstract

To provide a melt molding apparatus for a vibrator.SOLUTION: A melt molding apparatus includes a stage having a flat mounting surface. The melt molding apparatus includes a melt molding die that is disposed on the placement surface and includes a flat upper surface and a hole formed in a part of the upper surface about a central axis perpendicular to the upper surface. A burner is disposed above the central axis so as to face the hole and is configured to be able to generate a flame toward the hole. A burner disposed above the central axis so as to face the hole and configured to generate a flame toward the hole. A plate-like intermediate member arranged between the melting mold and the burner and having one or a plurality of opening parts is provided. A space is formed between the lower surface of the intermediate member and the upper surface of the melt-molding die.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present specification relates to a melt-molding apparatus for a transducer. [Background technology]

[0002] Patent Document 1 discloses a Bird-bath Resonator Gyroscope (BRG) that 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 upper surface. The hole is formed in part of the upper surface, centered on a central axis perpendicular to the upper surface of the molding die. A workpiece (e.g., a quartz plate) is placed so as to close the hole, the lower surface of the workpiece is decompressed, and the upper surface of the workpiece is heated with a burner. A hemispherical vibrator can be produced by melting and deforming the workpiece so that it fills the hole. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2018 / 079129 Summary of the Invention [Problem to be solved by the invention]

[0004] To create a vibrator with high symmetry about the central axis of the hole, it is necessary to input heat with a concentric temperature distribution about the central axis of the hole. However, burner flames tend to have low circularity in the cross section perpendicular to the radiation direction. This is because the flame direction and flame diameter at the outer edge of the flame constantly fluctuate (finely pulsate) due to fluctuations in the mixture state and flow rate of the combustion gas. For this reason, it has sometimes been difficult to create a vibrator with high symmetry. [Means for solving the problem]

[0005] The melt-forming apparatus disclosed in this specification includes a stage with a flat mounting surface. It also includes a melt-forming mold disposed on the mounting surface and having a flat upper surface and a hole formed in part of the upper surface centered on a central axis perpendicular to the upper surface. It also includes a burner disposed above the central axis facing the hole and configured to be able to generate a flame toward the hole. It also includes a plate-shaped intermediate member disposed between the melt-forming mold and the burner and having one or more openings. A space is formed between the lower surface of the intermediate member and the upper surface of the melt-forming mold.

[0006] In the above configuration, an intermediate member having an opening is placed between the melting and forming mold and the burner. Then, a flame is applied to the hole of the melting and forming mold through the opening. This allows the flame that has passed through the opening to be applied to the hole. Because the cross-sectional shape can be corrected by the opening, the circularity of the cross section of the flame applied to the hole can be increased. This makes it possible to improve the asymmetry of the flame temperature distribution with respect to the central axis. Because heat can be input with a concentric temperature distribution with respect to the central axis, it is possible to produce a vibrator with high symmetry. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic cross-sectional view of a melt-molding apparatus 1 of Example 1. FIG. [Figure 2] 1 is a top view of a melt-molding apparatus 1 according to a first embodiment. [Figure 3] FIG. 10 is a flow chart illustrating a manufacturing process of a vibrator. [Figure 4] FIG. 10 is an enlarged cross-sectional view of the vicinity of the hole 20h during the heating process. [Figure 5] FIG. 10 is a cross-sectional side view of a melt-molding apparatus 201 of Example 2. [Figure 6] FIG. 10 is a top view of a melt-molding apparatus 201 according to a second embodiment. [Figure 7] FIG. 10 is an enlarged cross-sectional view of the vicinity of the hole 20h during the heating process. DETAILED DESCRIPTION OF THE INVENTION [Example]

[0008] (Configuration of melt molding device 1) Fig. 1 shows a schematic cross-sectional view of the melt-forming apparatus 1. Fig. 2 shows a top view of the melt-forming apparatus 1. Fig. 1 corresponds to the cross-sectional view taken along line II in Fig. 2. Note that Fig. 2 omits the illustration of the burner 50, the movable mechanism 53, and the motorized stage 45. Fig. 2 also shows the forming die 20 and the quartz plate 30 hidden below the intermediate member 61 by dotted lines, and also shows the hole 20h hidden below the quartz plate 30 by dotted lines.

[0009] Motorized stage 45 is configured to be movable in the x and y directions (horizontal direction). Motorized stage 45 has a flat mounting surface 45s. Forming die 20 is mounted on mounting surface 45s via heat sink 40 and plate 10.

[0010] Heat sink 40 is disposed between motorized stage 45 and forming mold 20. Heat sink 40 is in contact with lower surface 10r of plate 10. Circulation piping 41 is disposed inside heat sink 40. Circulation piping 41 is connected to chiller equipment 42. A heat medium maintained at a constant temperature (e.g., 35°C) by chiller equipment 42 circulates through circulation piping 41. This allows heat sink 40 to maintain a constant temperature during processing.

[0011] The plate 10 is placed on the heat sink 40. The plate 10 is a stainless steel base on which the forming die 20 is placed. The plate 10 has the function of cooling the forming die 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 a negative pressure generating means 81 via a first communication path 10p1. The negative pressure generating means 81 is a means capable of generating a negative pressure in the hole portion 20h. The negative pressure generating means 81 may be, for example, a vacuum pump.

[0012] 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 in the shape of a disk 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 a part of the upper surface 20s. The hole 20h is a deformation space for melting and deforming the quartz plate 30. In this embodiment, the hole 20h has a shape hollowed out in a hemispherical shape centered on 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. A plurality of through holes 20e are formed in the bottom surface 20b, penetrating to the lower surface 20r. The through holes 20e communicate with the first communication holes 10c1.

[0013] The intermediate member 61 is a member for correcting the cross-sectional shape of the flame FL. The intermediate member 61 has a disk shape with a central axis CA. The intermediate member 61 has three or more legs 62 protruding downward from the lower surface of the intermediate member 61. The lower ends of the legs 62 are in contact with the surface 10s. The intermediate member 61 is disposed in the space between the forming die 20 and the burner 50 by the legs 62. The intermediate member 61 is also disposed apart from the upper surface 20s of the forming die 20 and parallel to the upper surface 20s. In other words, a space is formed between the lower surface and the upper surface 20s of the intermediate member 61. Various materials can be used for the intermediate member 61 as long as they are heat-resistant (e.g., tungsten, molybdenum). In this example, tungsten was used.

[0014] Intermediate member 61 has one opening 61h that corresponds to hole 20h of forming die 20. As shown in Fig. 2, opening 61h is circular and centered on central axis CA. An inner diameter D1 of opening 61h is larger than a diameter D0 of hole 20h.

[0015] 1 shows a cross section of opening 61h taken along a plane passing through central axis CA. Opening 61h has a tapered shape such that a lower inner diameter D1 is smaller than an upper inner diameter D1u. In other words, inner wall surface 61w of opening 61h has a tapered shape such that the opening area decreases downward.

[0016] Each of the four legs 62 is provided with an engaging portion 62c. The engaging portion 62c is a portion for fixing the relative positions of the forming die 20 and the intermediate member 61 by engaging them with each other. Specifically, the four legs 62 are arranged rotationally symmetrically on a circle centered on the central axis CA. The side walls of each of the four legs 62 are in contact with the outer peripheral surface of the intermediate member 61. This fixes the position of the intermediate member 61 in the x and y directions. In other words, the intermediate member 61 is fitted into the four legs 62. The contact portions between the legs 62 and the intermediate member 61 function as engaging portions 62c. When the relative positions of the forming die 20 and the intermediate member 61 are fixed, the centers of the hole 20h and the opening 61h coincide with the central axis CA. In other words, the centers of the hole 20h and the opening 61h coincide with each other.

[0017] 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 a material to be processed for forming the vibrator. The quartz plate 30 is made of fused silica. The thickness of the quartz plate 30 is, for example, 100 μm. In this embodiment, the quartz plate 30 is square, but it may also be circular or regular hexagonal.

[0018] The burner 50 is disposed above a central axis CA. The burner 50 includes a premixing chamber 50c, a tube 50t, and a burner tip 50s. A 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 includes 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 tube 50t extends downward from the premixing chamber 50c. The tube 50t is a cylindrical member having a burner central axis BA extending in the vertical direction. A burner tip 50s facing the hole 20h is disposed at the lower end of the tube 50t. A flame is generated from the burner tip 50s toward the hole 20h, thereby heating the quartz plate 30.

[0019] The burner 50 is fixed to a movable mechanism 53. The movable mechanism 53 is a mechanism that is movable in the vertical direction (±z direction) and in the xy plane direction parallel to the upper surface 20s. The movable mechanism 53 can move the burner tip 50s up and down along the central axis CA. The movable mechanism 53 can also move the position of the burner tip 50s within the two-dimensional xy plane while maintaining a substantially constant distance between the burner tip 50s and the upper surface 20s.

[0020] The radiation thermometer 80 is disposed at a position above the upper surface 20s by a fixing mechanism (not shown). The radiation thermometer 80 is a non-contact temperature sensor. The focus of the radiation thermometer 80 passes through the transparent quartz plate 30 and is aligned with the upper surface of the support 20p. This allows the temperature of the upper surface of the support 20p to be measured without contact. This makes it possible to indirectly measure the temperature of the quartz plate 30.

[0021] The control unit 70 is connected to the motorized stage 45, the movable mechanism 53, the gas flow regulator 52, the radiation thermometer 80, and the negative pressure generating means 81. The control unit 70 acquires various information from these devices and controls these devices. The control unit 70 may be, for example, a PC.

[0022] (Vibrator manufacturing process) The vibrator manufacturing process will be described using the flow diagram in Figure 3. In step S10, 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. The forming die 20 is placed on the surface 10s of the plate 10. In step S20, the quartz plate 30 is placed on the upper surface 20s of the forming die 20 within the opening 61h of the intermediate member 61. At this time, the quartz plate 30 is positioned so that the central axis CA coincides with the center of the quartz plate 30.

[0023] In step S30, intermediate member 61 is placed on surface 10s of plate 10. At this time, forming die 20 and intermediate member 61 are engaged with each other by engaging portion 62c. This allows automatic positioning so that the center of hole 20h and the center of opening 61h coincide with each other.

[0024] In step S40, first communication hole 10c1 is evacuated by negative pressure generating means 81. As a result, hole 20h is also evacuated via through-hole 20e, and quartz plate 30 is fixed by suction to upper surface 20s of casting mold 20. This results in the state shown in FIGS.

[0025] In step S50, the control unit 70 ignites the burner 50. The ignition is performed at a retracted position where the burner tip 50s is sufficiently separated from the surface of the quartz plate 30.

[0026] In step S60, the control unit 70 controls the movable mechanism 53 to lower the burner 50, thereby reducing the distance between the burner tip 50s and the quartz plate 30. This starts the process of heating the quartz plate 30 with the flame.

[0027] The timing to start the descent and the distance between the burner tip 50s and the quartz plate 30 can be controlled in various ways. For example, the descent may start when a preset time has elapsed since the burner 50 was ignited in step S50, and may stop when the burner tip 50s and the quartz plate 30 approach a predetermined distance. Also, for example, the temperature of the support 20p may be measured by a radiation thermometer 80, and the descent timing and the distance between the burner tip 50s and the quartz plate 30 may be determined by temperature feedback control.

[0028] FIG. 4 shows an enlarged cross-sectional view of the vicinity of the hole 20h during the heating process. Note that FIG. 4 omits the illustration of the heat sink 40 and the motorized stage 45, and only illustrates the vicinity of the burner tip 50s. During the heating process, the flame FL is directed toward the quartz plate 30 through the opening 61h. Here, the diameter of the flame FL is designated as flame diameter D2. In the technology described herein, the state of the flame FL and the position of the burner tip 50s are controlled so that the flame diameter D2 is larger than the inner diameter D1 of the opening 61h. This allows the flame diameter after passing through the opening 61h to be smaller than the flame diameter before passing through.

[0029] In the initial heating state, a gap is formed between the upper surface of the support 20p and the lower surface of the quartz plate 30, and they are not in contact. Therefore, no heat conduction path is formed from the quartz plate 30 to the support 20p. As a result, the temperature distribution of the quartz plate 30 is highest in the region near the support 20p at the center, and decreases as the temperature moves away from the support 20p toward the periphery. The center of the quartz plate 30 reaches the softening temperature (approximately 1600°C) first, and melting and deformation begins. A distributed load is applied to the quartz plate 30 due to the pressure difference between atmospheric pressure and the negative pressure inside the hole 20h. Therefore, as the quartz plate 30 is heated to its softening temperature, it can be melted and deformed so as to enter the hole 20h.

[0030] In step S70, if it is determined that the melting and deformation of the quartz plate 30 is completed (S70: YES), the process proceeds to step S80. Various methods for detecting the end point of processing may be used. For example, the end point of processing may be detected in response to the lapse of a predetermined processing time after the burner 50 is lowered in step S60.

[0031] In step S80, the control unit 70 controls the movable mechanism 53 to raise the burner 50. Then, when the burner 50 moves to the retracted position, the raising is stopped and the flame is extinguished.

[0032] In step S90, the control unit 70 waits for the cooling to be completed. Once the cooling is completed, the control unit 70 stops the negative pressure generating means 81. This opens the hole 20h to the atmosphere. In step S100, the fused and molded quartz plate 30 is removed from the forming mold 20. The unmolded area on the periphery of the quartz plate 30 is removed by a method such as CMP or laser cutting, thereby completing the vibrator.

[0033] (effect) In the technology of this embodiment, the flame FL that has passed through the opening 61h can be directed onto the quartz plate 30. Because the cross-sectional shape of the flame FL can be corrected by the opening 61h, the circularity of the cross section of the flame FL that is directed onto the quartz plate 30 can be improved. This can improve the asymmetry of the flame temperature distribution with respect to the central axis CA. Because heat can be input with a concentric temperature distribution with respect to the central axis CA, it is possible to manufacture a vibrator with high symmetry.

[0034] Furthermore, with the technology of this embodiment, the flame outer edge portion FLe can be blocked by the intermediate member 61. This makes it possible to suppress the influence of the pulsating flame outer edge portion FLe. Therefore, it is possible to improve the asymmetry of the flame temperature distribution with respect to the central axis CA.

[0035] In the technology of this embodiment, a space is formed between the lower surface of the intermediate member 61 and the upper surface 20s of the forming die 20. Therefore, it is possible to block the heat transfer path through which the heat of the flame outer edge portion FLe, which is blocked by the intermediate member 61, is transferred to the upper surface 20s. It is possible to prevent damage to the forming die 20 caused by the flame not used in processing the quartz plate 30.

[0036] The closer the cross-sectional shape of the flame is to a circle, the more symmetrical the shape of the manufactured oscillator can be. In the technology of this embodiment, the opening 61h is made circular with the center axis CA. This makes it possible to correct the cross-sectional shape of the flame FL that has passed through the opening 61h to a flame with high circularity.

[0037] In the technology of this embodiment, the opening 61h has a tapered shape. Therefore, the flame FL input into the upper inlet of the opening 61h can be concentrated and output from the lower outlet. In other words, the flame FL can be guided so as to be concentrated on the central axis CA. This makes it possible to improve heating efficiency.

[0038] (Modification of Example 1) Although the opening 61h has been described as being circular, the present invention is not limited to this. For example, the opening 61h may have a polygonal shape that is rotationally symmetric about the central axis CA. [Example]

[0039] (Configuration of melt molding device 201) FIG. 5 shows a cross-sectional side view of the melt-forming apparatus 201 of Example 2. FIG. 6 shows a top view of the melt-forming apparatus 201 of Example 2. FIG. 5 corresponds to the cross-sectional view taken along line VV in FIG. 6. Note that the burner 50, the movable mechanism 53, and the motorized stage 45 are omitted from FIG. 5. Also, in FIG. 6, the forming die 20 and the quartz plate 30 hidden below the intermediate member 61 are indicated by dotted lines. Also, only some of the multiple openings 63h are marked with reference numerals. Example 2 differs from Example 1 in the shape of the openings provided in the intermediate member 61. Parts common to the melt-forming apparatus 1 of Example 1 are marked with the same reference numerals, and description thereof will be omitted.

[0040] The intermediate member 61 has a plurality of openings 63h. Each of the plurality of openings 63h is circular and has the same opening diameter. The plurality of openings 63h are arranged rotationally symmetrically with respect to the central axis CA. The arrangement density of the plurality of openings 63h is lowest near the central axis CA and increases toward the outer periphery.

[0041] Here, the ratio of openings per unit area is defined as the aperture ratio of the intermediate member 61. A higher aperture ratio means a larger open area and easier flame passage. The arrangement density of the openings 63h is lowest near the central axis CA, so the aperture ratio of the intermediate member 61 is lowest near the central axis CA. The aperture ratio distribution can take various forms. The aperture ratio may increase continuously or stepwise as it moves radially outward from the central axis CA.

[0042] The focus of the radiation thermometer 80 is adjusted to the upper surface 61s of the intermediate member 61. As a result, even when the support 20p is hidden by the intermediate member 61 and the temperature of the support 20p cannot be measured, it is possible to indirectly estimate the temperature of the quartz plate 30 by measuring the temperature of the upper surface 61s.

[0043] (Heating process) The heating step in step S60 will now be described. Fig. 7 shows an enlarged cross-sectional view of the vicinity of the hole 20h during the heating step. Fig. 7 is the same as Fig. 4 of the first embodiment. In Fig. 7, reference numerals are assigned to only some of the openings 63h.

[0044] In the heating process, the flame FL is applied to the quartz plate 30 via the intermediate member 61. The flame FL applied to the upper surface 61s of the intermediate member 61 is transformed into a plurality of thin flames as it passes through each of the plurality of openings 63h. Then, a flame FL_A, which is a bundle of thin flames, is emitted from each of the plurality of openings 63h toward the quartz plate 30. Note that in FIG. 7, the flame FL_A is depicted as a single flame for ease of understanding.

[0045] Here, the diameter of the flame FL emitted from the burner tip 50s is defined as a first flame diameter D11. The diameter of the flame FL_A after passing through the intermediate member 61 is defined as a second flame diameter D12. The second flame diameter D12 corresponds to the diameter of a circle passing through the multiple openings 63h arranged on the outermost periphery. By passing through the intermediate member 61, the flame diameter can be expanded from the first flame diameter D11 to the second flame diameter D12.

[0046] (effect) In the technology of this embodiment, the cross-sectional shape of each of the multiple thin flames can be corrected by the multiple openings 63h. Then, the corrected thin flame bundle (flame FL_A) can be applied to the quartz plate 30. This can improve the asymmetry of the flame FL_A with respect to the central axis CA. Since heat can be input with a concentric temperature distribution with respect to the central axis CA, it is possible to manufacture a vibrator with high symmetry.

[0047] The heat input temperature distribution from the burner flame has a profile in which the temperature is highest at the central axis CA and decreases with increasing distance from the central axis CA in a direction perpendicular to the central axis CA. This creates a problem of differences in the ease of melting and deforming the quartz plate 30 depending on the location, which disrupts the geometric symmetry of the glass vibrator. To address this issue, the technology of this embodiment minimizes the aperture ratio of the intermediate member 61 near the central axis CA and increases it toward the outer periphery. This reduces the difference in heat input temperature between the central axis CA and its outer periphery, thereby broadening the profile of the heat input temperature distribution. Minimizing the difference in melting and deforming depending on the location makes it possible to manufacture a glass vibrator with good geometric symmetry.

[0048] With the technology of this embodiment, the diameter of the flame can be expanded from the first flame diameter D11 to the second flame diameter D12 before being applied to the quartz plate 30. This increases the area where the flame contacts the quartz plate 30, allowing the entire quartz plate 30 to be heated more uniformly. This reduces the difference in ease of melting and deformation depending on the location, making it possible to produce a glass vibrator with good shape symmetry.

[0049] (Modification of Example 2) The opening shapes of the plurality of openings 63h are not limited to circles but may be various shapes such as polygons or ellipses. Furthermore, the opening diameters of the plurality of openings 63h are not limited to being constant. For example, the opening diameters may be smallest near the central axis CA and may increase toward the outer periphery.

[0050] The opening ratio may be constant over the entire surface of the intermediate member 61. In this case, it is not necessary to align the center of the hole 20h with the center of the intermediate member 61.

[0051] The intermediate member 61 may be made of a metal mesh. In this case, the openings formed between the wires correspond to the plurality of openings 63h.

[0052] By changing the outermost position of the plurality of openings 63h, it is possible to set various diameters of the second flame diameter D12. For example, the second flame diameter D12 may be equal to or smaller than the first flame diameter D11.

[0053] Although specific examples of the present invention have been described above in detail, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and alterations of the specific examples exemplified above.

[0054] (Other variations) In this embodiment, the inner wall surface of the opening 61h of the intermediate member 61 has a linear tapered shape, but this is not limited to this. The tapered shape is not limited to a straight line, and may include a curved or stepped shape. Also, the tapered shape may be vertical without having a tapered shape.

[0055] The legs 62 may have various structures as long as they are capable of supporting the intermediate member 61. For example, the legs 62 may be cylindrical. The location where the legs 62 stand is not limited to the plate 10 and may be various. For example, the legs 62 may stand on the forming die 20. Alternatively, the intermediate member 61 may not have the legs 62 and may be supported by a support mechanism (not shown).

[0056] 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. Furthermore, the material of the vibrator is not limited to fused silica. Any dielectric material that melts and deforms can be used.

[0057] Furthermore, the technical elements described in this specification or drawings may exhibit technical utility 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 one of those objectives alone is technically useful.

[0058] Aspects of the present technology are listed below. [Aspect 1] a stage having a flat 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 plate-shaped intermediate member disposed between the melt-forming mold and the burner and having one or more openings; Equipped with a space is formed between the lower surface of the intermediate member and the upper surface of the melt-molding mold; Melt molding equipment. [Aspect 2] the intermediate member has a first opening; 2. The melt-forming apparatus of claim 1, wherein a center of the first opening coincides with the central axis. [Aspect 3] 3. The melt-molding apparatus according to claim 2, wherein the first opening has a circular shape centered on the central axis. [Aspect 4] 4. The melt-molding device according to claim 2 or 3, wherein a cross section of the first opening taken along a plane passing through the central axis has a tapered shape such that a lower opening width is smaller than an upper opening width. [Aspect 5] the intermediate member includes a leg portion protruding downward from a lower surface of the intermediate member, the leg portion is in contact with the melt-forming mold and includes an engaging portion configured to be able to fix a relative position between the intermediate member and the melt-forming mold, The melt-forming apparatus according to any one of aspects 2-4, wherein the center of the first opening and the center of the hole are aligned when the relative positions of the intermediate member and the melt-forming mold are fixed. [Aspect 6] 2. The melt-forming apparatus of claim 1, wherein the intermediate member includes a plurality of second openings. [Aspect 7] 7. The melt-molding apparatus according to claim 6, wherein the second openings are arranged rotationally symmetrically with respect to the central axis. [Aspect 8] 8. The melt-forming apparatus according to claim 6 or 7, wherein the aperture ratio of the intermediate member is smallest in the vicinity of the central axis. [Aspect 9] the intermediate member includes a leg portion protruding downward from a lower surface of the intermediate member, the leg portion is in contact with the melt-forming mold and includes an engaging portion configured to be able to fix a relative position between the intermediate member and the melt-forming mold, The melt-forming apparatus according to any one of aspects 6 to 8, wherein the center of the intermediate member and the center of the hole are aligned with each other while the relative positions of the intermediate member and the melt-forming mold are fixed. [Explanation of symbols]

[0059] 1: Melt forming device 10: Plate 20: Mold 20h: Hole 20p: Support 20s: Upper surface 30: Quartz plate 50: Burner 61: Intermediate member 61h: Opening 60: Upper surface member 60h: Opening CA: Central axis

Claims

1. a stage having a flat 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 plate-shaped intermediate member disposed between the melt-forming mold and the burner and having one or more openings; Equipped with a space is formed between the lower surface of the intermediate member and the upper surface of the melt-molding mold; Melt molding equipment.

2. the intermediate member has one first opening; The melt-forming device according to claim 1 , wherein a center of the first opening coincides with the central axis.

3. The melt-molding device according to claim 2 , wherein the first opening has a circular shape centered on the central axis.

4. The melt-molding device according to claim 3 , wherein a cross section of the first opening taken along a plane passing through the central axis has a tapered shape in which a lower opening width is smaller than an upper opening width.

5. the intermediate member includes a leg portion protruding downward from a lower surface of the intermediate member, the leg portion is in contact with the melt-forming mold and includes an engaging portion configured to be able to fix a relative position between the intermediate member and the melt-forming mold, The melt-molding device according to any one of claims 2 to 4, wherein the center of the first opening and the center of the hole are aligned when the relative positions of the intermediate member and the melt-molding mold are fixed.

6. The melt-forming device of claim 1 , wherein the intermediate member includes a plurality of second openings.

7. The melt-molding device according to claim 6 , wherein the plurality of second openings are arranged rotationally symmetrically with respect to the central axis.

8. The melt-molding apparatus according to claim 7 , wherein the open area ratio of the intermediate member is smallest in the vicinity of the central axis.

9. the intermediate member includes a leg portion protruding downward from a lower surface of the intermediate member, the leg portion is in contact with the melt-forming mold and includes an engaging portion configured to be able to fix a relative position between the intermediate member and the melt-forming mold, The melt-molding device according to any one of claims 6 to 8, wherein a center of the intermediate member and a center of the hole are aligned with each other in a state where the relative positions of the intermediate member and the melt-molding mold are fixed.

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