JPWO2013111837A1 - Glass lump forming apparatus, glass lump manufacturing method, glass molded product manufacturing method, and optical element manufacturing method - Google Patents

Abstract

In the glass lump molding apparatus (1), the supply flow path connected to the gas supply section is branched toward each of the plurality of molds (102A, 102B), and each branched flow path (106aA, 106aB) after branching Are connected to the corresponding glass molds (102A, 102B) to communicate with the through hole group (102H), and narrow the branch flow paths (106aA, 106aB) in the respective branch flow paths (106aA, 106aB). A diaphragm portion (118A, 118B) is provided. The cross-sectional area (S1) of the branch flow passages restricted by the restricting portions (118A, 118B) appears on the cut surface when the through hole group (102H) is cut in the direction orthogonal to the axial direction. It is smaller than the sum W of each cross-sectional area. With this glass lump forming apparatus (1), the molten glass can be stably floated in each of the glass forming dies.

Description

  The present invention relates to a glass lump forming apparatus capable of forming a glass lump (glass gob) for precision press molding from molten glass, a production method for producing a glass lump using this apparatus, and a glass produced by this method. The present invention relates to a manufacturing method for manufacturing a glass molded article or an optical element by heating and pressing a lump.

  2. Description of the Related Art A glass lump forming apparatus that supplies molten glass flowing down from a molten glass supply unit to a glass mold and forms it into a glass lump for precision press molding is known. A specific configuration of this type of molding apparatus is described in, for example, Japanese Patent Application Laid-Open No. 2002-326823.

  In the glass lump forming apparatus described in the patent document (Japanese Patent Laid-Open No. 2002-326823), a plurality of glass forming dies are arranged on the turntable at equal intervals in the circumferential direction, and the turntable is rotated. Each glass mold is sequentially transferred to a predetermined stop position. Thereby, the supply (cast) of the molten glass to each glass mold and the take-out of the glass lump formed in the glass mold are sequentially performed. This type of glass lump forming apparatus has one gas supply unit, distributes the gas supplied from this gas supply unit to each glass mold, and ejects the distributed gas from the through holes of the glass mold. In this state, the molten glass flowing down from the molten glass supply unit can be formed into a glass lump.

JP 2002-326823 A

  When manufacturing a glass lump, in a plurality of glass forming dies, casting and taking out (take-out) are performed sequentially and cyclically. Therefore, when the glass lump forming apparatus is viewed as a whole, molten glass is supplied. There are a glass mold that is formed into a glass lump and an empty glass mold that is not supplied with molten glass. Here, when the molten glass is cast in one glass mold, the pressure of the gas supplied to the glass mold increases due to glass floating, and the gas flow rate to the other glass mold increases. Although the total flow rate of the gas supplied from the gas supply unit is constant, the gas flow rate to the other glass mold increases, so the gas flow rate to the glass mold in which the molten glass is cast decreases. For this reason, the floating of the molten glass becomes unstable. For example, when the molten glass comes into contact with the glass mold and is rapidly cooled, distortion (surface wrinkles, etc.) occurs in the glass lump after molding. Further, the distortion generated at this time may cause breakage of the glass called can cracking.

  Thus, when the gas pressure fluctuates between the glass molds, the fluctuation affects the gas pressure in the other glass molds, and the floating state of the molten glass in each glass mold becomes unstable. be pointed out. Then, this invention is made | formed in view of said situation, The place made into the objective is providing the shaping | molding apparatus of a glass lump suitable for making a molten glass float stably in each glass shaping | molding die. It is. Moreover, it is providing the manufacturing method of a glass lump, and the manufacturing method of a glass molded product.

  An apparatus for forming a glass lump according to an aspect of the present invention includes a plurality of glass forming dies having a forming surface in which a through hole group including a plurality of through holes is formed, and is sent from a predetermined gas supply unit. Formed into a glass lump of a predetermined shape while receiving the molten glass supplied to the molding surface in a floating state by the pressure of the gas ejected from the group of through holes of each glass mold through the path It is a device to do. In the gas flow path, the supply flow path connected to the gas supply section is branched toward each of the plurality of molding dies, and each branched flow path after branching is connected to the corresponding glass mold. It communicates with the through hole group. In addition, each branch channel is provided with a throttle portion that throttles the branch channel. The cross-sectional area of the branch channel (squeezed part) constricted by this restricting part is the sum of the cross-sectional areas of each of the plurality of through-holes that appear on the cut surface when the through-hole group is cut in the direction orthogonal to the axial direction Smaller than.

  According to the glass lump forming apparatus of the present invention, it is possible to provide a glass lump suitable for stably floating a molten glass in each of a plurality of glass forming dies. Moreover, the manufacturing method which can shape | mold a glass lump in the stable floating state and the manufacturing method which can manufacture a highly accurate glass molded article using the glass lump manufactured by this method are provided.

It is a side view which shows the structure of the shaping | molding apparatus of the glass lump which concerns on embodiment (1st Embodiment) of this invention. It is a top view which shows the structure of the shaping | molding apparatus of the glass lump which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the internal structure of the glass shaping | molding die and turntable with which the glass lump shaping | molding apparatus which concerns on 1st Embodiment of this invention was equipped. It is a figure which shows the structure of the shaping | molding apparatus of the glass lump which concerns on the modification 1 of 1st Embodiment of this invention. It is sectional drawing which shows the structure around the glass forming die of the glass lump shaping | molding apparatus which concerns on the modification 2 of 1st Embodiment of this invention. It is a side view which shows the structure of the shaping | molding apparatus of the glass lump which concerns on 2nd Embodiment of this invention. FIG. 3 is an explanatory auxiliary diagram of manufacturing conditions shown in Table 1.

  In the following description, when forming a glass lump from molten glass, the molten glass supplied onto the mold may come into contact with the mold (molding surface) instantaneously, but the molten glass is the mold (molding surface). In the following specification, this meaning is also included in the floating state since contact within a range where no fusion occurs is also in a substantially floating state.

<Glass lump forming device and glass lump production>
Hereinafter, a glass lump forming apparatus according to an embodiment (first embodiment) of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view showing a configuration of a glass lump forming apparatus according to an embodiment (first embodiment) of the present invention. FIG. 2 is a top view showing the configuration of the glass lump forming apparatus according to the first embodiment of the present invention. As shown in FIGS. 1 and 2, the glass lump forming apparatus 1 includes a glass forming mold 102, a molten glass supply unit 104, a turntable 106, a direct drive motor 108, a heating furnace 110, and a take-out means. 112, a glass lump collection unit 114, and a gas pipe 116.

  The upper part of the molten glass supply unit 104 communicates with a work tank, a clarification tank, and a glass melting tank not shown. Thereby, melted, clarified and homogenized molten glass is continuously supplied to the molten glass supply unit 104. From the tip (outflow nozzle 104a) of the molten glass supply unit 104, the molten glass controlled to a constant temperature flows down. The molten glass flowing down from the outflow nozzle 104a is received by the glass mold 102 and formed into a glass lump having a predetermined shape.

  As shown in FIG. 2, a plurality of glass molds 102 are installed on the turntable 106 at equal intervals around the rotation center. The turntable 106 is assumed to be made of, for example, a lightweight and high-strength aluminum alloy. The turntable 106 is intermittently driven by a direct drive motor 108. Thereby, each glass forming mold 102 stops at a stop position (cast position) A and a stop position (extraction position) B for a predetermined time.

  A plurality of gas pipes 116 are installed on the lower surface side of the turntable 106. Each gas pipe 116 has one end connected to the corresponding glass forming mold 102 and the other end connected to a single gas supply unit common to all gas pipes. In FIG. 2, for the sake of clarity, the gas pipe 116 is indicated by a one-dot chain line.

  A method for forming a glass lump (glass gob) used for reheat press molding by the glass lump forming apparatus 1 will be described. First, in order to form a glass lump of a predetermined weight from the molten glass, the clarified and homogenized molten glass is continuously flowed down from the outflow nozzle 104a at a constant speed at the casting position A. The molten glass that has flowed down is successively supplied to the glass mold 102 that is sequentially transferred to the casting position A. A gas (for example, air or nitrogen) supplied from the gas supply unit via the gas pipe 116 is ejected from the glass mold 102. Therefore, the molten glass is formed into, for example, a predetermined spherical glass lump while being received by each glass forming mold 102 in a floating state by the gas jet pressure. At this time, the molten glass may come into contact with the glass mold 102. However, this is an instantaneous contact, and the molten glass is instantaneously released from the glass mold 102. Therefore, there is little possibility of a problem in forming an accurately shaped glass lump.

  In the heating furnace 110a, the glass lump molded in the glass mold 102 is gradually cooled until it is taken out. Next, the glass lump in the glass mold 102 transferred to the take-out position B is blown off to the substantially fan-shaped glass lump collection unit 114 by the blowing gas from the take-out means 112. The blown glass lump is collected by the glass lump collection unit 114. In the heating furnace 110b, the glass mold 102 is adjusted to a temperature suitable for forming a glass lump. Thus, in each glass forming die 102, casting of molten glass, forming of a glass lump, and taking out of the glass lump are sequentially performed. Each glass mold 102 is returned to the casting process after the glass lump is taken out, and used in a circulating manner.

  In addition, as a casting method of the molten glass to the glass forming die 102, for example, a method of dropping molten glass by its own weight (dropping cutting method) from the outflow nozzle 104a, a glass forming die 102 at the casting position A is used as the outflow nozzle 104a. The glass forming mold 102 is moved closer to (advanced to) the tip, receives the tip of the molten glass flow flowing down from the outflow nozzle 104a, and after the molten glass reaches a predetermined weight, at a speed faster than the flowing speed of the molten glass flow. A method of dropping a predetermined weight of molten glass from the molten glass flow (falling cutting method) is mentioned.

  FIG. 3 is a cross-sectional view showing the internal structure of the glass mold 102 and the turntable 106. The glass mold 102 according to the first embodiment is made of, for example, lightweight and high-strength carbon or stainless steel, and is fixed on the turntable 106 as shown in FIG. Inside the turntable 106, a gas channel 106a connected to the gas pipe 116 and a pair of branch channels 106aA and 106aB branched from the gas channel 106a are formed.

  The glass mold 102 is provided with a pair of glass molds 102A and 102B. The glass molds 102A and 102B have concave molding surfaces 102Aa and 102Ba, respectively. Each of the glass molds 102A and 102B has a plurality of through holes 102H penetrating from the surfaces of the molding surfaces 102Aa and 102Ba to the bottom surfaces of the glass molds 102A and 102B.

  The substantially semi-elliptical spherical spaces defined by the surface shapes of the molding surfaces 102Aa and 102Ba communicate with the branch flow paths 106aA and 106aB through the respective through holes 102H. Therefore, the gas supplied from the gas supply section through the gas pipe 116, the gas flow path 106a, and the branch flow path 106aA is ejected upward from the surface of the molding surface 102Aa through the plurality of through holes 102H. In addition, the gas supplied from the gas supply section through the gas pipe 116, the gas flow path 106a, and the branch flow path 106aB is ejected upward from the surface of the molding surface 102Ba through the plurality of through holes 102H. In principle, the gas flow rate G supplied from the gas supply unit to the gas flow path 106a via the gas pipe 116 is constant.

  As shown in FIGS. 2 and 3, at the casting position A, first, the molten glass is cast into the glass mold 102A, and is floated in the molding surface 102Aa by the gas jet pressure (at this time, the molten glass and the molding surface 102Aa). For example, it is formed into a predetermined spherical glass lump. At the time of casting, first, because the cross section formed on the upper end portion side (the side from which the gas GA is released) of the glass mold 102A is received by the tapered inner peripheral portion (hereinafter referred to as the inner peripheral portion), The glass molds 102A and 102B are raised. In this state, the molten glass flowing down from the glass supply portion is received by the inner peripheral portion of the glass mold 102A, and when the molten glass reaches a predetermined weight, the glass molds 102A and 102B are faster than the flowing speed of the molten glass. The glass is lowered at a speed to cut the molten glass (falling cutting method). In this way, the molten glass is supplied. After casting, the molten glass is moved into the molding surface 102Aa and maintained in a state of being floated by the gas supplied from the gas supply unit. Next, the turntable 106 rotates intermittently, and the glass mold 102B is transferred to the casting position A. Similarly, the glass forming mold 102B is cast into the molten glass by the descending cutting method, and is cast into a predetermined spherical glass lump while the cast molten glass is received in a floating state within the forming surface 102Ba. Is done. In the above description, the example in which the molten glass is received at the inner peripheral portion has been described. However, the molten glass can be directly supplied from the outflow nozzle 104a to the molding surfaces 102Aa and 102Ba without being received at the inner peripheral portion. Moreover, when receiving molten glass, you may receive on the upper end surface of glass forming mold 102A, 102B instead of an inner peripheral part.

  Thus, at the casting position A, the molten glass is sequentially cast onto the glass molds 102A and 102B. In this case, when the molten glass is cast only on the glass mold 102A, the outlet side of the branch channel 106aA (the narrowed portion 118A side is the inlet side of the branch channel 106aA and the through hole 102H side is the outlet side) When the pressure is applied to the weight of the molten glass, the gas flow rate to the glass mold 102B increases and the gas flow rate to the glass mold 102A decreases at the same time. As a result, the molten glass floats in the molding surface 102Aa. Becomes unstable, and there is a concern that the molten glass and the molding surface 102Aa come into contact with each other to cause molding defects. However, in the glass lump forming apparatus 1 of the first embodiment, as shown in FIG. 3, throttle portions 118A and 118B having the same cross-sectional area are formed on the inlet sides of the branch flow paths 106aA and 106aB, respectively. Therefore, even when molten glass is supplied to only one of the glass molds (for example, only the glass mold 102A), the gas flow rate fluctuation to the glass mold (glass mold 102A) is reduced. Since the portion (squeezed portion 118A) suppresses, a gas flow rate necessary for stably floating the molten glass can be ensured. The reason why “the gas flow rate necessary to stably float the molten glass can be secured” will be described later.

  As shown in FIG. 3, the narrowed portion 118A is cut when the cross-sectional area of the branch channel 106aA (the cross-sectional area taken in the vertical direction in FIG. 3) is cut in the direction perpendicular to the axial direction of the through hole 102H. More than the sum (W1 + W2 +... + Wn) of the cross-sectional areas (W1, W2,..., Wn) of all the through holes 102H of the glass mold 102A appearing on the surface (hereinafter referred to as “hole area sum W”). (Hereinafter, for convenience of explanation, the flow path narrowed by the narrowed portion 118A is referred to as “throttle portion 118Aa”.) Therefore, when the molten glass is cast only on the glass mold 102A, pressure is applied to the outlet side (through hole 102H side) of the branch flow path 106aA by the weight of the molten glass. Is absorbed in the space between the outlet in the branch channel 106aA and the throttle part 118Aa (hereinafter referred to as “buffer 106bA”), and the pressure on the throttle part 118Aa (inlet) side does not substantially vary. Therefore, the gas flow rate to the branch flow path 106aB does not change, and the gas flow rate supplied to the branch flow path 106aA does not change. That is, the throttle portions 118Aa and 118Ba control the flow rate of the gas flowing before each throttle portion. For this reason, the gas flow rate GA ejected from the surface of the molding surface 102Aa can secure a flow rate necessary to stably float the molten glass even when the molten glass is supplied. Even when it is in contact with the molding surface 102Aa or even when it is in contact with the molding surface 102Aa, the mold is instantaneously released from the molding surface 102Aa by the gas ejected from the surface of the molding surface 102Aa so Can be obtained. The molten glass is cooled by the molding surface 102Aa near the surface of the contact portion at the moment of contact with the molding surface 102Aa. However, if the contact time is very short, the surface portion of the cooled molten glass is warmed by the heat inside the molten glass, and the viscosity decreases to become a free surface, so that molding defects such as wrinkles and irregularities remain. do not do. In other words, if the contact time with the molding surface 102Aa is very short, the influence of the molten glass is eliminated, and the molten glass is molded into a glass block having an accurate shape.

  In addition, the restricting portion 118B restricts the cross-sectional area of the branch flow channel 106aB so as to be smaller than the sum of the hole areas of the glass mold 102B (hereinafter, for convenience of explanation, the flow restricting portion 118B is referred to as “ This will be referred to as the aperture 118Ba ”.) Therefore, when the molten glass is also cast into the glass mold 102B, the pressure is applied to the outlet side (through hole 102H side) of the branch flow path 106aB by the weight of the molten glass. Is absorbed in the space between the outlet in the branch channel 106aB and the throttle part 118Ba (hereinafter referred to as “buffer 106bB”), and the pressure on the throttle part 118Ba side does not substantially vary. Therefore, the gas flow rate to the branch flow path 106aA does not change, and the gas flow rate supplied to the branch flow path 106aB does not change. That is, similarly to the throttle portion 118Aa, the throttle portion 118Ba also controls the flow rate of the gas flowing before the throttle portion 118Ba. For this reason, the gas flow rate GB ejected from the surface of the molding surface 102Ba can ensure the flow rate necessary to stably float the molten glass even when the molten glass is supplied. Even if it is not in contact with 102Ba or in the case of contact, it can be released from the molding surface 102Ba instantaneously by the gas pressure, and a stable floating state can be obtained in the molding surface 102Ba.

  As described above, in the glass lump forming apparatus 1 of the first embodiment, even if the molten glass is not in contact with the forming surfaces 102Aa and 102Ba, or even when the molten glass is in contact with each other, the mold is instantaneously released by the gas pressure. Since molding is performed in a stable floating state in 102Aa and 102Ba, generation of molding defects due to contact between the molten glass and the molding surface is suppressed.

  In FIG. 3, the cross-sectional areas of the branch flow paths (106aA, 106aB) are narrowed by the throttle portions (118A, 118B). Here, the cross-sectional areas of the branch flow paths 106aA and the respective cross-sectional areas of the branch flow paths 106aB are shown. Is S1 (same). Further, the cross-sectional area in the narrowed portions (118A, 118B) is formed uniformly.

In FIG. 3, the cross-sectional areas of the narrowed portions (118A, 118B) are uniform (same), but the cross-sectional areas change in the narrowed portions (118A, 118B) (not so uniform). In).
Further, when the cross-sectional area is not uniform in each throttle part (118A, 118B) (for example, in the throttle part 118A of FIG. 3, the lower surface of the throttle part 118A is formed in a tapered shape, 106aA has a smaller cross-sectional area on the inlet side than the cross-sectional area of the gas flow path 106a), the smallest cross-sectional area in each throttle part (118A, 118B) is adopted, and this cross-sectional area is the sum of the hole areas W What is necessary is just to become smaller than (W1 + W2 + ... + Wn).
In this case, in order to allow the gas to flow into the buffers 106bA and 106bB by the same amount, the shape of the restricting portions (118A and 118B) provided in the glass forming dies 102A and 102B is made symmetrical. It is desirable to do.
The branch flow paths (106aA, 106aB) are formed in the same shape (volume).

<Manufacture of glass molded products>
A glass lump (glass gob) formed using the glass lump forming apparatus 1 of the first embodiment is introduced into a press mold, heated and softened together with the press mold, and press-molded in a softened state. After being cooled in a pressurized state in the mold, it is taken out from the press mold. Thereby, a glass molded product (for example, lens blanks) is obtained. The lens blanks thus manufactured are subjected to various grinding / polishing processes to obtain glass optical elements (spherical lenses).

<Variation 1 of the first embodiment>
In the first embodiment, the descending cutting method is used as the method for casting the molten glass onto the glass mold 102, but in the first modification, the dropping cutting method is used. Specifically, the dripping cutting method will be described using, for example, FIG. 4A described later. The molten glass is allowed to flow down from the outflow nozzle, and the molten glass that has flowed down is naturally generated by its own weight and surface tension. Using the control method of rotating the turntable 106Z in synchronization with the timing at which the molten glass is dropped, the dropped molten glass is once applied to the tapered portion provided in the mold 102Z, and then applied to the mold 102Z. Shows how to supply.

  FIG. 4 is a diagram illustrating a configuration of a glass lump forming apparatus 1Z according to Modification 1 of the first embodiment. 4A is a top view, and FIG. 4B is a diagram showing a cross section taken along the line CC in FIG. 4A. For convenience of explanation, FIG. 4 shows only the glass mold 102Z and the turntable 106Z among the components of the glass lump forming apparatus 1Z. In addition, in each embodiment after the modification 1 of 1st Embodiment, the same or similar code | symbol is attached | subjected and demonstrated to the same or similar structure as the glass lump shaping | molding apparatus 1 shown in FIGS. 1-3. Are simplified or omitted. Moreover, the glass lump formed in each of the first and subsequent embodiments of the first embodiment is introduced into a press mold as in the first embodiment, and is molded as lens blanks by reheat press molding. .

  As shown in FIG. 4, the glass mold 102 </ b> Z includes a single glass mold unlike the glass mold 102 of the first embodiment. Further, the turntable 106Z includes a table top plate body 1061 in which a plurality of glass forming dies 102Z are incorporated at equal intervals around the rotation center, and a table base 1062 that supports the entire top plate body 1061 from below. . The central shaft body of the table base 1062 is formed with a hollow portion (reference numeral 106a because it is used as a gas flow path), and the upper end of the hollow portion opens at the center of the upper surface of the table base 1062. In addition, a circular recess (reference numeral 106a because it is used as a gas flow path) is formed in the center of the table base 1062, and the gas flow path 106a is connected to the lower surface of the top plate 1061. It stipulates. From the outer edge of the circular recess of the table base 1062, a plurality of grooves that connect the glass forming molds 102 </ b> Z and the gas flow paths 106 a are formed to extend radially, and between the lower surface of the top plate body 1061. A branch channel 106aZ is defined.

  A narrowed portion 118Z (cross-sectional area S) is formed in each branch channel 106aZ. The restricting portion 118Z restricts the sectional area of the branch flow path 106aZ to be smaller than the sum of the hole areas W (W1 + W2 +... + Wn) of the glass forming die 102Z. Therefore, also in the modification 1 of 1st Embodiment, the fluctuation | variation of the gas flow rate to each glass forming mold 102Z resulting from the cast state with respect to each glass forming mold 102Z is suppressed. Therefore, in the glass mold 102Z, the molten glass can be released instantly by the gas pressure without contact with the mold 102Z, or to obtain a stable floating state in the mold 102Z. Can do. Moreover, in the modification 1 of 1st Embodiment, the structure which prescribes | regulates the flow path for supplying the gas of a gas supply part to each glass forming die does not appear in an external appearance, but is formed in the turntable 106Z. Therefore, the height dimension of the apparatus can be suppressed.

<Modification 2 of the first embodiment>
FIG. 5 is a cross-sectional view showing a configuration around the glass forming mold 102Z of the glass lump forming apparatus of Modification 2 of the first embodiment. Each branch channel 106aY of the second modification extends radially in the horizontal direction from the center side to the peripheral side of the turntable 106Z, and then bends in the vertical direction. As shown in FIG. It communicates with the buffer 106bZ of 102Z. A throttle portion 118Y is formed at the base end of the branch channel 106aY. The restrictor 118Y (cross-sectional area S) restricts the cross-sectional area of the branch channel 106aY to be smaller than the sum of the hole areas W (W1 + W2 +... + Wn) of the glass mold 102Z. Therefore, also in this modification 2, the fluctuation | variation of the gas flow rate to each glass forming die 102Z resulting from the cast state with respect to each glass forming die 102Z is suppressed. Accordingly, in the glass mold 102Z, the molten glass is released from the mold 102Z instantaneously by the gas pressure without contact with the glass mold 102, and stably floated on the mold 102Z. The state can be obtained.

Second Embodiment
FIG. 6 is a side view showing the configuration of the glass lump forming apparatus 1X of the second embodiment. In the present embodiment, as in the first embodiment, a configuration (gas pipe 116X) that defines a gas supply flow path to each glass forming die 102Z is installed on the lower surface side of the turntable 106. In the present embodiment, unlike the first embodiment in which the throttle portion 118 is provided in the turntable 106, the throttle portion 118X is formed in the middle of the gas pipe 116X. The restrictor 118X restricts the cross-sectional area S of the branch flow path 106aX in the gas pipe 116X so as to be smaller than the hole area sum W (W1 + W2 +... + Wn) of the glass mold 102Z. Therefore, also in this embodiment, the fluctuation | variation of the gas flow rate to each glass forming mold 102Z resulting from the cast state with respect to each glass forming mold 102Z is suppressed. Accordingly, in the glass mold 102Z, the molten glass is released from the molding surface of the glass mold 102 instantly by the gas pressure without contacting the glass mold 102 or even when it is in contact with the glass mold 102Z. A stable levitation state can be obtained.

<Example>
Next, a specific example of manufacturing a glass lump performed using the glass lump forming apparatus 1 of the first embodiment and a comparative example thereof will be described. Table 1 shows the manufacturing conditions of the glass lump in each of Examples 1-8. FIG. 7 shows an auxiliary diagram for explaining the manufacturing conditions shown in Table 1. In Table 1, “Glass diameter” indicates the diameter X (unit: mm) of the glass lump that is scheduled to be formed, and “Die diameter” indicates the distance d (unit: mm) between the center lines (FIG. 7). reference). Specifically, the distance d between the center lines is the center line of the pair of through holes 102H located at the outermost periphery across the center of the molding surfaces 102Aa and 102Ba among all the through holes 102H formed in the glass mold. Defined as the distance between. “Outflow temperature” (unit: ° C.) and “weight” (unit: mg) indicate the temperature and weight of the molten glass flowing down from the outflow nozzle 104a, respectively. “DPM” (unit: pieces / min) indicates the number of glass lumps produced per minute. The “floating gas flow rate” (unit: ml / min) indicates the flow rate per minute of the gas ejected from all the through holes 102H in each glass mold. “Sphericality” (unit:%) is a value obtained by (minor axis / major axis) × 100 of the formed glass lump. In addition, various shapes, such as a rectangle and circular, are assumed for the aperture | diaphragm | squeeze part of each Example.

Table 2 shows the results of Examples 1, 3, and 4. In Table 2, “yield” (unit:%) is a value when the following glass ingots (1) to (3) are formed as defective moldings.
(1) Glass lump whose surface is wrinkled by contact with the molding surface of the glass mold (2) Glass lump whose sphericity is 90% or less by deformation due to contact with the molding surface of the glass mold ( 3) A glass lump that was locally quenched by contact with the molding surface of the glass mold and cracked.

As shown in Table 2, in Examples 1, 3, and 4, since the area S of the narrowed portion is smaller than the hole area sum W (W1 + W2 +... + Wn), the molten glass floats stably on the molding surfaces 102Aa and 102Ba. Molded in a state. Therefore, in Examples 1, 3, and 4, it was confirmed that the yield of the glass block was high.
In the above description, when a glass lump is produced using the glass lump forming apparatus according to the embodiment of the present invention, even when the molten glass is supplied to the glass mold, “to make the molten glass float stably” The necessary gas flow rate can be ensured ", but this is presumed from the results of the above examples. That is, as shown in Table 2 above, a very high yield was obtained when the glass lump was molded using the glass lump forming apparatus according to the embodiment of the present invention. Is confident that the gas flow rate necessary to stably float the molten glass from the through holes provided in each glass mold can be secured. In addition, although the explanation was made assuming that the gas flow rate does not fluctuate when the molten glass is supplied to the glass mold, it is within a range in which the gas flow rate necessary to float the molten glass can be secured (a range that does not cause molding failure). If there is, the gas flow rate may vary.

  The above is the description of the embodiment of the present invention. The present invention is not limited to the above-described configuration, and various modifications can be made within the scope of the technical idea of the present invention. For example, the present invention is not limited to this, and a glass ball can be formed as a glass lump. And the surface of the shape | molded glass elementary sphere can be roughened by various well-known grinding | polishing methods, such as barrel grinding | polishing, and a glass molded product can be shape | molded by reheat press molding. Also, the glass spheres produced by subjecting the surface of the formed glass spheres to various known rough polishing and fine polishing processes such as smoothing and CG (curve generator) processing, and the manufactured glass spheres An optical element such as an aspherical lens can be processed by performing precision press molding on (precision glass sphere).

  Finally, embodiments of the present invention will be summarized with reference to the drawings and the like.

  The glass lump forming apparatus (1) according to the embodiment of the present invention is formed with a through hole group (102H) including a plurality of through holes (102H) as shown in FIGS. A plurality of glass molds (102, 102A, 102B, 102Z) having surfaces (102Aa, 102Ba) are provided. Each glass mold (102, 102a, 102B, 102Z) is sent from a predetermined gas supply unit and passed through a gas flow path (106a). The melt supplied to the molding surface (102Aa, 102Ba) in each glass molding die (102, 102A, 102B, 102Z) by the pressure of the gas ejected from the through hole group (102H) of 102A, 102B, 102Z) While receiving glass, it is formed into a glass lump of a predetermined shape. In the gas flow path (106a), the supply flow path connected to the gas supply section is branched toward each of the plurality of molds (102, 102A, 102B, 102Z), and each branched flow path (106aA, 106aB, 106aY) communicates with the through hole group (102H) by being connected to the corresponding glass mold (102, 102A, 102B, 102Z), and in each branch channel (106aA, 106aB, 106aY), A throttle section (118A, 118B, 118X, 118Y) that throttles the branch flow path (106aA, 106aB, 106aY) is provided, and a cross-sectional area of the branch flow path narrowed by the throttle section (118A, 118B, 118X, 118Y) A plurality of through-holes (1), (S1, S) appear on a cut surface when the through-hole group (102H) is cut in a direction orthogonal to the axial direction. The sum W of the cross-sectional area of each 2H) (W1 + W2 + ... + Wn) less than.

  Preferably, as shown in FIGS. 1 to 7, the glass lump forming apparatus (1) according to the embodiment of the present invention is configured such that a plurality of glass forming dies (102, 102 A, 102 B, 102 Z) are circular By rotating the table (106, 106Z) arranged side by side in the circumferential direction and the table (106, 106Z), each of the plurality of glass forming dies (102, 102A, 102B, 102Z) is cast position of the molten glass, And table rotating means (108) for sequentially and cyclically transferring to the take-out position.

  More preferably, as shown in FIGS. 1 to 5, branch flow paths (106 a A) connected to the respective glass molds (102, 102 A, 102 B, 102 Z) inside the tables (106, 106 Z). , 106aB, 106aY, 106aZ).

  More preferably, as shown in FIGS. 1 to 7, a plurality of glass forming dies (102, 102A, 102B, 102Z) are formed on the upper surface of the table (106, 106Z).

  More preferably, as shown in FIGS. 6 and 7, the branch channel (106X) includes a pipe (116X) that connects the supply channel (106a) and each glass mold (102). The throttle part (118X) is formed in the pipe.

  The glass lump manufacturing method of the present invention includes a step of supplying molten glass in order to each of a plurality of glass molds (102, 102A, 102B, 102Z) as shown in FIGS. A step of forming the molten glass into a glass lump having a predetermined shape, and a step of taking out the glass lump formed into a predetermined shape from a glass mold.

  Preferably, in the method for producing a glass lump of the present invention, as shown in FIGS. 1 to 7, a molten glass is sequentially applied to each of a plurality of glass molds (102, 102A, 102B, 102Z). A step of supplying, a step of forming the supplied molten glass into a glass lump having a predetermined shape while receiving the molten glass on the molding surface (102Aa, 102Ba) of the glass mold (102, 102A, 102B, 102Z), and a predetermined shape And a step of taking out the glass lump formed into a glass mold (102, 102A, 102B, 102Z).

As shown in FIGS. 1 to 7, the method for producing a glass molded product of the present invention includes a step of introducing the glass mass produced using the method for producing a glass mass of the present invention into a predetermined press mold. And a step of press-molding the glass lump introduced into the predetermined press-molding die in a softened state, and a step of taking out the press-molded glass molded product from the press-molding die.
As shown in FIGS. 1 to 7, the optical element manufacturing method of the present invention is a glass sphere by polishing the surface of the glass block manufactured using the glass lump manufacturing method of the present invention. A step of producing, a step of introducing the glass sphere into a predetermined press mold, and a step of heating the glass sphere introduced into the press mold and precision press-molding the softened glass sphere.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Glass lump shaping | molding apparatus 102, 102A, 102B, 102Z Glass shaping | molding die 102Aa, 102Ba Molding surface 102H Through-hole 104 Molten glass supply part 104a Outflow nozzle 106, 106Z Turntable 106a Gas flow path 106aA, 106aB, 106aY Branch flow path 106bA , 106bB Buffer 108 Direct drive motor 110, 110a, 110b Heating furnace 112 Extraction means 114 Glass lump collection unit 116 Gas piping 118A, 118B, 118X, 118Y Restriction unit 118Aa, 118Ba Restriction unit.

Claims (9)

A plurality of glass forming dies having a forming surface in which a through hole group composed of a plurality of through holes is formed, and are sent from a predetermined gas supply unit and from the through hole group of each glass forming die via a gas flow path. In the glass lump forming apparatus for forming into a glass lump of a predetermined shape while receiving the molten glass supplied to the forming surface in each glass forming die by the pressure of the jetted gas,
The gas flow path is
A supply flow path connected to the gas supply unit is branched toward each of the plurality of molding dies,
Each branch flow path after branching communicates with the through hole group by being connected to a corresponding glass mold,
In each of the branch flow paths, a throttle part for restricting the branch flow path is provided,
The cross-sectional area of the branch flow path constricted by the constricted portion is larger than the sum of the cross-sectional areas of each of the plurality of through-holes appearing on the cut surface when the through-hole group is cut in a direction perpendicular to the axial direction A small glass lump forming device. A table in which the plurality of glass molds are arranged in the circumferential direction;
A table rotating means for sequentially and cyclically transferring each of the plurality of glass forming molds to the cast position and the take-out position of the molten glass by rotating the table;
The glass lump forming apparatus according to claim 1, comprising:   The apparatus for forming a glass lump according to claim 2, wherein a branch passage connected to each glass forming die is formed inside the table.   The glass lump forming apparatus according to claim 2 or claim 3, wherein the plurality of glass forming dies are formed on an upper surface of the table. The branch flow path includes a pipe connecting the supply flow path and each glass mold,
The glass lump forming apparatus according to claim 1 or claim 2, wherein the narrowed portion is formed in the pipe. A glass lump manufacturing method for forming a glass lump having a predetermined shape using the glass lump forming apparatus according to any one of claims 1 to 5,
Supplying molten glass in turn to each of the plurality of glass molds;
Forming the supplied molten glass into a glass lump of a predetermined shape;
A step of taking out the glass block molded into the predetermined shape from the glass mold;
The manufacturing method of the glass lump containing this. A glass lump manufacturing method for forming a glass lump of a predetermined shape using the glass lump forming apparatus according to any one of claims 1 to 6,
Supplying molten glass in turn to each of the plurality of glass molds;
Forming the glass melt having a predetermined shape while receiving the supplied molten glass on the molding surface of the glass mold; and
A step of taking out the glass block molded into the predetermined shape from the glass mold;
The manufacturing method of the glass lump containing this. A step of introducing a glass lump produced using the method for producing a glass lump according to claim 6 or claim 7 into a predetermined press mold;
A step of press-molding the glass lump introduced into the predetermined press-molding mold in a softened state;
A step of taking out the press-molded glass molded product from the press mold; and
A method for producing a glass molded article, comprising: A step of producing glass spheres by subjecting the surface of the glass lump produced using the method for producing a glass lump according to claim 6 or claim 7 to polishing;
Introducing the glass sphere into a predetermined press mold;
Heating the glass sphere introduced into the press mold, and precision press-molding the softened glass sphere;
A method for manufacturing an optical element, comprising:

Images