JP4845802B2 - Melt outflow nozzle - Google Patents

Description

  The present invention relates to a melt outflow nozzle for causing a melt such as molten glass to flow out to form a spherical or oval or flat spherical shaped body. Particularly preferably, optical elements such as optical pickup lenses such as DVD, CD and magneto-optical disk (MO), lenses for mobile phones with cameras, lenses for optical communication, optical devices, etc., or optical elements thereof. Concerning a melt outflow nozzle for forming fine spherical particles for use as a preform material for obtaining elements by precision press or as fine metal balls such as solder balls used for micro soldering in semiconductor devices, etc. It is.

  In recent years, along with the development of micro engineering, development of design / manufacturing technology of a micro optical system composed of micro optical elements such as micro lenses has been performed. In particular, since practical application of optical communication systems began to be studied, optical pickup lenses such as DVDs, CDs, magneto-optical disks (MO), etc., lenses for camera-equipped mobile phones, optical communication lenses, optical devices, etc. As an optical element such as a lens or a prism, or an imaging element for an optical fiber or a semiconductor laser, a microlens has begun to be widely adopted and put into practical use.

  On the other hand, with the widespread use of compact discs and DVDs, lenses used for pickups, video camera lenses, and the like are required to have high-precision optical performance despite their small outer diameters.

  In order to process these products from glass, conventionally, the glass has been directly processed into a spherical surface by polishing, but it is costly and takes time.

  Also, fine metal spheres that require narrow particle size distribution and high sphericity in many fields, such as solder balls for micro soldering performed in semiconductor devices, balls for fine ball bearings used in micro machines, etc. Needs are growing.

  Therefore, a method for producing these glass-made elements and fine metal spheres with high accuracy at low cost and in large quantities has been studied (for example, Patent Document 1).

  In the method disclosed in Patent Document 1, the molten glass is discharged into the gas phase from the orifice while applying vibration to the molten glass to form glass droplets, and the glass droplets are solidified while dropping to form fine spherical particles. Is to be manufactured. In producing such fine spherical particles, when the glass in the crucible is melted and clarified, the glass is solidified inside the outflow pipe of the molten glass or the tip of the nozzle to form the spherical particles. In general, the temperature of the outflow pipe is raised when starting, and the glass solidified inside the tip of the nozzle is heated with a burner or the like to start outflow of molten glass. However, when the molten glass starts to flow out, the glass is wetted on the outer surface of the nozzle, and the tip of the nozzle may be dumped. In such a state, the molten glass cannot flow out as a glass flow having a constant flow rate and a constant shape, and accurate microspheres cannot be obtained. Therefore, it was considered to stop the glass outflow and remove the glass wetted at the tip of the nozzle by heating with a burner or the like, but the glass could not be removed sufficiently from the tip of the nozzle. Since the glass remaining at the tip of the nozzle further wets up, minute spherical particles could not be produced stably.

  In Patent Documents 2 and 3, a method of forming a spherical or elliptical glass body (preform material) by dropping a molten glass lump from the molten glass at the tip of the outflow pipe by gravity and the surface tension of the molten glass. Is disclosed. However, in such a method for producing a glass body, the molten glass wets and adheres to the vicinity of the tip of the nozzle and often cannot flow out a glass flow having a constant flow rate and a constant shape. Further, since the wet glass is held there for a long time and cooled to a certain temperature by the outside air, devitrification occurs in the glass, and the molten glass that has generated devitrification is mixed into falling glass droplets and obtained. It was easy to cause a defect due to devitrification in the glass body.

For this reason, development of a melt outflow nozzle capable of forming a spherical material such as a preform material or a glass element, which can flow out a melt flow having a constant flow rate and a constant shape, without causing the melt of glass or the like to wet and adhere is required. It was done.
JP 2003-104744 A Japanese Examined Patent Publication No. 7-51446 JP 2001-089159 A

  The present invention relates to a melting method used in a method or apparatus for accurately producing a large amount of fine spherical particles or preform material by gravity and surface tension in the process of flowing out a melt from a melt outflow nozzle and dropping the melt. When manufacturing fine spherical particles or preform materials in a material outflow nozzle, there is very little wetting of the melt into the nozzle, and the glass that has wetted at the tip of the nozzle can be easily and completely removed. It is to provide a melt outlet nozzle that can be used.

  In order to solve the above-mentioned problems, the present inventors have conducted extensive test studies, and as a result, in the melt outflow nozzle used in an apparatus for outflowing the melt to form fine spherical particles or preform materials, By keeping the centerline average roughness (Ra) of the surface of the material within a predetermined range, spherical particles such as minute melt droplets or preform materials can be accurately and stably hardly generated. As a result, the present invention has been completed.

  More specifically, the present invention provides the following.

  (1) In the melt outflow nozzle in which the flow path of the melt is formed, an inner surface facing the flow path, an outer surface that covers the inner surface, and an end surface that connects the inner surface and the outer surface at the tip, A melt outflow nozzle characterized by having an outer surface centerline average roughness (Ra) of 1.6 μm or less.

  (2) The melt outflow nozzle according to (1), wherein a center line average roughness (Ra) of the end face is 1.6 μm or less.

  (3) The melt outflow nozzle according to (1) or (2), wherein a center line average roughness (Ra) of the inner surface is 1.6 μm or less.

  (4) The melt outflow nozzle according to any one of (1) to (3), wherein at least the outer surface is made of platinum or a platinum alloy.

  (5) The melt outflow nozzle according to any one of (1) to (4), wherein a cross section perpendicular to the melt outflow direction is substantially a circle or an ellipse with respect to the outer surface.

  (6) The melt outflow nozzle according to any one of (1) to (5), wherein the end face is perpendicular to the melt outflow direction.

(7) Any one of (1) to (6), wherein the cross-sectional area a ₁ is 40 mm ² or less when the cross-sectional area perpendicular to the melt outflow direction is a ₁ The melt outlet nozzle described in 1.

  (8) The melt outflow nozzle according to any one of (1) to (7), wherein the inner surface has a circular cross section perpendicular to the melt outflow direction.

  (9) The melt outflow nozzle according to any one of (1) to (7), wherein the melt is a molten glass.

  (10) A spherical particle forming apparatus having the melt outflow nozzle according to any one of (1) to (9).

  (11) A spherical glass forming apparatus having the melt outflow nozzle according to any one of (1) to (9).

  (12) A glass molded body forming apparatus having the melt outflow nozzle according to any one of (1) to (9).

  (13) A spherical particle manufacturing method for forming a melt into a spherical shape using the spherical particle forming apparatus according to (10).

  (14) A spherical glass manufacturing method for forming a glass into a spherical shape using the spherical glass forming apparatus according to (11).

  (15) A glass molded body manufacturing method for manufacturing a glass molded body using the glass molded body molding apparatus according to (12).

  In a melt outflow nozzle for producing a melt molded body, preferably a fine spherical particle or a preform material, wetting is very little and the glass that has been wetted at the tip of the nozzle is easily and completely removed. A melt outlet nozzle can be obtained.

  For this reason, the melt outflow nozzle of the present invention can be suitably used for producing a melt formed body, preferably fine spherical particles or a preform material.

  Hereinafter, the present invention will be specifically described.

  The melt outflow nozzle of the present invention has a melt flow path formed therein, and includes an inner surface facing the flow path, an outer surface covering the inner surface, and an end surface connecting the inner surface and the outer surface at the tip, The center line average roughness (Ra) of the outer surface is 1.6 μm or less.

  Hereinafter, embodiments of the melt outflow nozzle of the present invention will be described in detail. However, the present invention is not limited to the following embodiments at all, and appropriately modified within the scope of the object of the present invention. Can be implemented. In addition, about the location where description overlaps, description may be abbreviate | omitted suitably, However, The meaning of invention is not limited.

  Embodiments of the melt outflow nozzle of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of a melt outflow nozzle 1 according to an embodiment of the present invention, and FIG. 2 is a perspective view illustrating each inner surface and each outer surface of the melt outflow nozzle 1 according to an embodiment of the present invention. FIG. 3 is a longitudinal sectional view taken along a plane parallel to the melt outflow direction and passing through the center of the melt outflow nozzle 1. FIG. 4 is a plan view of the melt outflow nozzle 1 according to the embodiment of the present invention.

As shown in FIGS. 2 and 3, the melt outflow nozzle 1 of the present embodiment includes an inner surface 31 that faces the flow path 6, an outer surface 32 that covers the inner surface 31, and an end surface 21 that connects the inner surface 31 and the outer surface 32 with the tip 2. The center line average roughness (Ra) of the surface of the outer surface 32 is set within a predetermined range. Furthermore, it is comprised from the outflow part 3 which flows out a molten material, the inclination part 4 which continues to the outflow part 3, and the inflow part 5 which continues to the inclination part 4, and flows in a melt, and a melt is contained inside A cylindrical melt outflow nozzle 1 in which a flow path 6 is formed, the shape of the flow path 6 being continuous with the inner surface 31 located on the outflow side of the melt and the inner surface 31, the first flow path a second inner surface 41 which changes from the cross-sectional area a ₁ to the second flow path cross-sectional area a _2, continuous with the second inner surface 41, the third inner surface 51 having a second flow path cross-sectional area a _2, a a, and exhibits a first flow path cross-sectional area a ₁ second flow channel shape larger cross-sectional area a ₂ than.

Here, the channel cross section means a surface surrounded by inner surfaces (the inner surface 31, the second inner surface 41, and the third inner surface 51) of the melt outflow nozzle 1 appearing in a vertical section in the melt outflow direction. The channel cross-sectional area means the area of such a channel cross section. The first flow path cross-sectional area a ₁ means the area of the flow path cross section (A _{1 in} FIG. 2) in the portion of the inner surface 31 that appears in the vertical cross section in the melt outflow direction (arrow direction in FIG. 3). The second channel cross-sectional area a ₂ means the area of the channel cross section (A _{2 in} FIG. ₂ ) in the portion of the third inner surface 51 that appears in the vertical cross section in the melt outflow direction.

The outer shape of the melt outflow nozzle 1 is continuous with the outer surface 32 having the first outer cross-sectional area b ₁ located on the melt outflow side, and the first outer cross-sectional area b ₁ to the _first outer cross-sectional area b ₁ . a second outer surface 42 that changes the second outer cross-sectional area b _2, contiguous with the second outer surface 42 has a third outer surface 52 having a second outer cross-sectional area b _2, a, and a second outer It found the following first outer cross-sectional area b ₁ and has a shape smaller than the cross-sectional area b _2.

Here, the outer cross section means a surface surrounded by the outer shapes (outer surface 32, second outer surface 42, and third outer surface 52) of the melt outflow nozzle 1 appearing in a vertical cross section in the melt outflow direction. Means the area of such an external cross section. The first outer cross-sectional area b ₁ means the area of a cross section (B _{1 in} FIG. 2) surrounded by the outer shape of the melt outflow nozzle 1 appearing in the vertical cross section in the melt outflow direction in the outer surface 32 portion. The second outer cross-sectional area b ₂ means the area of a cross section (B _{2 in} FIG. ₂ ) surrounded by the outer shape of the melt outflow nozzle 1 that appears in the vertical cross section of the second outer surface 52 in the melt outflow direction.

  The melt outflow nozzle 1 of the present embodiment is one in which the outer surface 32 is formed so that the center line average roughness (Ra) of the outer surface 32 is 1.6 μm or less (see FIG. 1).

  The melt outflow nozzle 1 generally has a slight difference depending on the melt composition such as glass, the viscosity of the melt determined by the melt composition, and the material composition of the melt outflow nozzle. It has the property of being easily wetted. If the wettability of the melt with respect to the melt outflow nozzle 1 is high, the melt flows to the outer surface side of the melt outflow nozzle 1 when the outflow of the melt starts or when the melt flows out and melts. A phenomenon of wetting upward occurs on the outer surface of the material outflow nozzle 1. And the wet melted material becomes a lump at the tip 2 of the melt flow-out nozzle 1, and it becomes difficult for the melt to flow out. Alternatively, devitrification occurs due to wetting, which causes a defect in the resulting molded body.

  By setting the center line average roughness (Ra) of the outer surface 32 of the melt outflow nozzle 1 within a predetermined range, it is possible to easily remove the melt that has been wet and adhered from the outer surface 32. Further, since the wettability of the outer surface 32 with respect to the melt can be changed by changing the center line average roughness (Ra) of the outer surface 32, the melt wets and adheres to the outer surface 32 of the melt outflow nozzle 1. Can be prevented. Therefore, it is possible to stably flow out a glass flow having a constant flow rate and a fixed shape from the melt outflow nozzle 1, and it is possible to stably form a large amount of fine spherical particles or preform materials with high accuracy.

  Here, the center line average roughness (Ra) of the outer surface 32 of the melt outflow nozzle 1 is preferably 1.6 μm or less, more preferably 0.8 μm or less, and most preferably 0.2 μm or less. By setting the center line average roughness (Ra) to 1.6 μm or less, it is possible to effectively suppress the wetting of the glass against a material having high wettability with respect to the glass, and the melt adhering to the outer surface 32 can be easily obtained. Can be removed.

  However, in order to reduce the processing cost of the melt outflow nozzle 1, the center line average roughness (Ra) of the outer surface 32 of the melt outflow nozzle 1 is preferably more than 0.025 μm.

  Here, the center line average roughness (Ra) is a value measured in accordance with JIS-B0601: 2001, and when it cannot be measured in accordance with JIS-B0601: 2001, it is a standard by roughness made of super hard material. It is a value measured by comparing with a product being processed under a microscope with reference to a test piece.

  In addition to the outer surface 32, the center line average roughness (Ra) of the end surface 21 (see FIG. 4) or the inner surface 31 (see FIG. 3) is preferably 1.6 μm or less. More preferably, the line average roughness (Ra) is the same as the center line average roughness of the outer surface 32. By setting the center line average roughness (Ra) of the end surface 21 and the inner surface 31 within this range, the flow of the melt is stabilized, and the accuracy and homogeneity of the molded product are improved.

The shapes of the channel cross sections A ₁ and A ₂ of the flow channel 6 of the melt outflow nozzle 1 and the outer cross sectional shapes B ₁ and B ₂ of the outer surface shape are not particularly limited, but are easy to process, the melt outflow nozzle 1 From the viewpoint of reducing the strength of the melt and the disturbance of the melt flow, it is preferable that the shape is similar at all positions. Further, from the viewpoint of easily detaching the melt adhered to the outer surface 32, the outer cross section at the position of the outer surface 32 is more preferably a substantially circular shape or a substantially oval shape, and it flows out from the outlet of the melt outlet nozzle 1. From the standpoint that the melt outflow shape immediately after forming tends to be a columnar shape and it is easy to obtain a substantially spherical or substantially elliptical shaped body, the flow path cross section at the position of the inner surface 31 is substantially circular or substantially elliptical. Is more preferable. Further, the melt outflow nozzle 1 has no unevenness, and the cross section of the flow path and the outer cross section are concentric, so that the temperature distribution of the melt in the vicinity of the melt outflow nozzle 1 is likely to be uniform and uniform. This is most preferable because a molded body is easily obtained.

  The end surface 21 of the melt outflow nozzle 1 only needs to be connected to the inner surface 31 and the outer surface 32 by the tip 2 and the shape thereof is not particularly limited, but is preferably perpendicular to the melt outflow direction. By making the end surface 21 perpendicular to the melt outflow direction, the end surface 21 can be easily formed, and the mechanical strength in the vicinity of the outlet can be sufficiently increased.

The size of the melt outlet channel cross-sectional area a ₁ in the portion of the inner surface 31 of the nozzle 1 _(see FIG. 2) may be appropriately designed by a spherical grain size to be manufactured. The upper limit of the flow path cross-sectional area a ₁ is preferably 40 mm ² or less when molding spherical particles or preform materials having a diameter of 6 mm or more, and molding spherical particles or preform materials having a diameter of 2.5 mm to less than 6 mm. preferably 30 mm ² or less if the if the diameter shaping the spherical particles or preform material below 2.5mm is preferably 40 mm ² or less. Within magnitude is within this range the flow passage cross-sectional area a _1, can be preferably used for the production of spherical particles or preform material.

  The cross-sectional shape obtained by cutting the melt outflow nozzle 1 in a direction perpendicular to the melt outflow direction is not specified as a circle as in the present embodiment. For example, as shown in FIG. It may be a shape such as a rectangle.

  Examples of the material constituting the melt outflow nozzle 1 of the present invention include platinum and platinum alloys. Platinum or platinum alloy is stable at high temperatures and has the property of preventing impurities from being mixed into the melt. Therefore, it is also preferable for the production of glass that requires a particularly high melting temperature and low impurities. Can be used.

  The melt outflow nozzle 1 of the present invention may be integrated with a guide path that guides the melt from the holding container to the melt outflow nozzle 1, and a desorption function is provided between the guide path and the melt outflow nozzle 1. It may be provided and used on a taxiway.

  As a specific example, the front end portion of the surface where the outlet of the guide path is formed and the inflow portion 5 of the melt outflow nozzle 1 are brought into close contact with each other so that the outlet and the inflow portion 5 are connected, and screwed or the like. Install by means of or weld. At this time, if the close contact is not properly made, the melt enters between the tip of the conduit portion and the melt outflow nozzle 1, and the melt leaks out from the melt outflow nozzle 1. It is necessary to attach at least to the extent that the melt does not leak.

  The melt outflow nozzle 1 of the present invention is produced by, for example, machining. Specifically, a commercially available general tool or drill is modified to make a special tool, and a semi-finished product is made by using this tool to open a through-hole having a size close to a predetermined hole diameter at the center of a cylindrical material. To manufacture. Thereafter, a wire having a predetermined hole diameter is manufactured, and wire polishing is performed on the inner surface of the through hole using a wire and diamond abrasive. Further, the outer surface of the material is cut into a predetermined outer surface shape, and the melt outflow nozzle 1 having a desired center line average roughness (Ra) is manufactured by polishing using, for example, a polishing cloth or a grindstone. . In addition, the preparation method of the said melt outflow nozzle 1 is an example, Comprising: You may produce the melt outflow nozzle 1 which has desired centerline average roughness (Ra) by another method.

[Spherical grain forming equipment]
Next, an example of a spherical particle forming apparatus for producing spherical particles such as spherical glass using the melt outflow nozzle 1 of the present invention will be described. Note that this spherical particle forming apparatus is merely an example and is not limited to the following, and may be any apparatus that forms a melt into spherical particles.

  FIG. 6 is a cross-sectional view of a spherical particle forming apparatus 7 incorporating the melt outflow nozzle 1 of the present invention. The spherical particle forming device 7 includes a holding container 8 made of platinum or the like for holding a melt C such as glass, metal, or resin, and a furnace body 9 for heating and / or connecting (supporting) the holding container 8. Prepare. In addition, a guide path 10 for guiding the melt C to the melt outflow nozzle 1 is connected to the lower part of the holding container 8, and the melt C passes through the guide path 10 from the holding container 8 to the melt outflow nozzle. It flows out from 1 in a column shape. The melt C that has flowed out falls in the air, and is separated by gravity or surface tension during the fall to form a spherical shape. The formed spherical particles fall into the liquid 111 in the recovery means 11.

  The melt C is not particularly limited as long as it is intended to produce spherical particles, and includes melted inorganic composition, metal, organic composition, etc., and may be molten glass, molten metal, molten resin, or the like. .

  The holding container 8 includes a stirrer 81 for stirring the melt C in the holding container 8 and a heating device (not shown). The holding container 8 only needs to melt a raw material made of glass, metal, resin, or the like, and a known holding container can be used.

  When the melt C is a molten glass, the holding container 8 can melt and clarify the glass. For example, a known container such as a heater (not shown) is used to set the temperature of the melt to a predetermined temperature. It may be possible to keep it in a state. The stirrer 81 rotates in the horizontal direction and stirs and homogenizes the melt with a stirring blade (not shown), but may be omitted if necessary.

  The furnace body 9 made of a heat-resistant material such as a refractory brick covering the periphery of the holding container 8 is not particularly limited as long as it can withstand the temperature of the holding container 8.

  The guide path 10 is connected to the lower part of the holding container 8 and guides the melt C in the holding container 8 to the melt outflow nozzle 1. The induction path 10 is provided with a heater (not shown), and the viscosity of the melt in the induction path 10 is controlled by controlling the temperature of the induction path 10, and the flow rate of the melt C in the induction path 10 is controlled. It can be controlled.

  The melt outflow nozzle 1 is connected to the guide path 10, and the guide path 10 and the flow path 6 in the melt outflow nozzle 1 communicate with each other. The melt outflow nozzle 1 may be integrated with the guide path 10. Further, a heater (not shown) may be provided, and the viscosity of the melt C may be controlled by controlling the temperature of the melt C flowing out from the tip 2 of the melt outflow nozzle 1. As the heating method, a known method such as heating by electric current heating, high-frequency heating, infrared heating, or combustion of a gas using a burner or the like can be used.

  If necessary, an exciter that vibrates the guide path 10 and / or the melt outflow nozzle 1 is connected to the guide path 10 and / or the melt outflow nozzle 1 in order to easily obtain spherical particles with higher mass accuracy. May be. Even if the vibrator is directly attached to the melt outflow nozzle 1 and / or the guide path 10, a desired effect can be obtained.

  In addition, the holding container 8 is provided with a raw material inlet (not shown). When the raw material inlet is closed, it may be structured to be in a sealed state. Further, when the holding container 8 is provided with a pressure adjusting means (not shown), the holding container 8 has a pressure resistance that is structurally durable when pressurized or depressurized by the pressure adjusting means. You may make it take a structure.

  The pressure adjusting means applies pressure to the liquid level of the melt C in the holding container 8, and causes a certain amount of the melt C to flow out to the guide path 10 regardless of the storage amount of the melt C in the holding container 8. Can do.

  For example, when the storage amount of the melt C in the holding container 8 is large, the inside of the holding container 8 can be depressurized by the pressure adjusting means, and a large amount of the melt C can be prevented from flowing out to the guide path 10. Further, when the storage amount of the melt C in the holding container 8 is small, it is possible to prevent the melt C from becoming difficult to flow out to the guide path 10 by being pressurized in the holding container 8 by the pressure adjusting means. The pressure adjusting means can be adjusted by the pressure inside the sealed furnace body 9.

  Next, a method for producing spherical particles using the spherical particle forming apparatus 7 incorporating the melt outflow nozzle 1 of the present invention will be described.

  First, a raw material made of glass, metal or the like is melted, and the melt is held in the holding container 8. If necessary, the stirrer 81 may be rotated, and the melt may be stirred and homogenized with a stirring blade.

  Next, the melt is guided from the guide path 10 to the melt outflow nozzle 1 of the present invention, and the melt is flowed out from the melt outflow nozzle 1. The melt falls into the air in the form of a continuous flow with a narrow diameter from the melt outflow nozzle 1 or in the state of dripping.

  The melt that has fallen into the air is formed into a spherical shape by gravity and surface tension, and is recovered in the recovery means 11. At this time, by dropping the spherically formed melt into the liquid 111 in the recovery means 11, the liquid 111 absorbs the impact and cools the spherically formed melt.

[Spherical grain forming method]
Next, a method for forming spherical particles by the spherical particle forming apparatus 7 will be described with reference to FIG.

  The method for forming spherical particles is a method for forming a spherical particle such as a melt droplet by causing a melt to flow out from a nozzle, wherein the melt outflow nozzle 1 of the present invention is used as the nozzle. is there.

  In a method for forming spherical particles such as melt droplets, a melt as a starting material is prepared by a well-known method, homogenized by clarification and stirring, and accumulated in a holding container 8. A guide path 10 for guiding the internal melt C to the melt outflow nozzle 1 is connected to the bottom of the platinum holding container 8. The melt C passes through the guide path 10 and the melt outflow nozzle. Reach 1

  The holding container 8, the guide path 10, and the melt outflow nozzle 1 are temperature controlled in order to keep the temperature of the internal melt C at an appropriate level, and the melt C at a constant flow rate is the outflow portion 3 of the melt outflow nozzle 1. Spill from.

  The melt C flowing out in a columnar shape from the melt flow-out nozzle 1 is successively separated into melt drops having a constant weight, and formed into spherical particles by surface tension.

  As a method for separating the above-mentioned constant weight melt, the viscosity of the melt is controlled by controlling the temperature of the melt outlet nozzle 1 and the guide passage 10, and the flow rate and flow rate are changed with the change of the melt viscosity. The melt may be changed into a droplet-like melt lump that flows out from the melt outflow nozzle 1 as a continuous flow and drops from the continuous flow in a line.

  Examples of the present invention will be described below, but the scope of the present invention is not limited to these examples.

<Example>
A nozzle for producing a microsphere having a diameter of 1 mm was prepared. A cylindrical material made of platinum was prepared, and a through-hole with a hole diameter of 0.8 mm was formed in the center of this material using a commercially available tool modified from a cutting tool and a drill. Thereafter, a wire having a diameter of 0.5 mm was manufactured, and wire polishing was performed on the inner surface of the through hole using a wire and diamond abrasive. At the same time, the edge and the outer surface of this material are cut into a predetermined shape, and the inner surface, the outer surface, and the end surface have a center line average roughness (Ra) of 0.2 μm by polishing using a polishing cloth or a grindstone. A melt effluent nozzle was obtained. Here, the center line average roughness (Ra) of the outer peripheral surface of the nozzle is determined by referring to a standard test piece by roughness made of cemented carbide, and comparing the polishing roughness with the product being processed under a microscope. Was measured.

The manufactured nozzle had concentric circles in the cross section of the flow path and the outer cross section, and the size of the cross section of the flow path was 0.52 mm ² .

<Comparative example>
A melt outflow nozzle was obtained in the same manner as in Example except that only the outer surface of the cylindrical material made of platinum was cut and the polishing process was not performed. The center line average roughness (Ra) of the inner surface, outer surface, and end surface of this nozzle was 1.7 μm.

<Evaluation>
The melt outflow nozzle thus obtained was installed in a spherical particle forming apparatus. Then, the wettability at the start of outflow, the stability at the start of outflow, the stability during the outflow, and the returnability at the time of wet up were evaluated. The wettability at the start of outflow means that the melt is solidified inside the tip of the melt outflow nozzle, and this melt is heated with a burner or the like to start outflow of the melt. The frequency of getting wet on the outside. The stability at the start of the outflow refers to the frequency at which the disturbance of the melt flow observed visually occurs within 5 seconds immediately after the start of the outflow of the melt. Disturbance of the melt flow means that the flowing direction is not determined due to twisting of the flowing melt. Stability during outflow refers to the frequency of occurrence of visually disturbed melt flow that occurs after more than 5 seconds from the start of outflow of the melt. The recoverability upon wetting refers to the frequency at which the molten material that wets and adheres to the outer surface of the molten material outflow nozzle does not flow all together and remains in a granular form when heated by a burner.

  About these evaluation items other than the recoverability at the time of wetting, the outflow of glass was repeatedly evaluated 20 times. About the resettability at the time of wetting up, artificially attaching and removing glass on the outer surface of the nozzle was repeatedly evaluated 20 times, and the results are shown in Table 1 below.

  From the above examples, it is proved that the melt outflow nozzle of the present invention has very little wetting of the melt to the nozzle and can easily and completely remove the glass wetted at the tip of the nozzle. It was.

<Use to form glass sphere>
The melt outflow nozzle produced as described above was provided at the bottom of a platinum crucible of the melting furnace via a platinum pipe. Heavy lanthanum flint glass [L-LAH53 manufactured by OHARA INC.] Was used as the glass that was melted by the platinum crucible. Moreover, while arrange | positioning a liquid tank in the position of about 5 m below a melt outflow nozzle, water was put in the liquid tank. In this state, 10 kg of the glass was put into a platinum crucible and heated and melted.

  The furnace temperature after heating and melting was 1050 ° C., the temperature at the rear end of the platinum pipe was 1050 ° C., the temperature at the front end of the platinum pipe was 1100 ° C., and the temperature at the front end of the melt outflow nozzle was maintained at 1150 ° C. Moreover, the outflow amount (flow rate) of the molten glass from the melt outflow nozzle in the above state was 1.5 kg to 1.6 kg / hr.

  The molten glass that has flowed out of the nozzle under the conditions as described above flows down as a continuous flow from the nozzle tip to about 10 mm below, and below that, it changes into a drop-like glass lump arranged in a row, It fell as a glass lump. And the said glass lump further fell in the liquid tank, it was cooled while being absorbed by the water in a liquid tank, and was collect | recovered in the liquid tank. The glass lump collected from the liquid tank was washed to produce fine spherical particles made of glass.

<Use to form semiconductor sphere>
The melt outflow nozzle produced as described above was provided at the lower end of the melting furnace. 100 g of silicon was put in a melting crucible and melted at a melting temperature of 1420 ° C. in the melting furnace. When the silicon meltdown is completed, pressure is applied to the melting crucible with argon or helium to extrude the molten silicon from the melt outflow nozzle and drop the molten silicon, which is provided under the melt outflow nozzle. Silicon spheres were produced by cooling in the cooling oil in the recovery container. In this example, the silicon spheres could be stably obtained without the molten silicon getting wet to the nozzle.

<Use for forming metal balls>
The melt outflow nozzle produced as described above was provided at the bottom of a crucible made of carbon. The crucible was charged with 5 kg of oxygen-free copper as a raw material, and while lowering the cylinder and closing the melt outlet nozzle at the lower end of the vibrating rod, heating in the crucible was started in an argon atmosphere to melt the copper. The high frequency induction heater was set so that the temperature in the crucible was 1150 ° C. The carbon ring attached to the nozzle was heated by receiving a high frequency from a high frequency induction heater. After the copper charged in the crucible was completely melted, the cylinder was raised and the melt outlet nozzle was opened. The vibrating rod was vibrated at 4000 Hz, and argon gas was injected so that the pressure in the crucible was 0.03 MPa. The droplets ejected from the nozzle were cooled and solidified with quenching oil, and then collected, degreased, washed and dried to obtain copper spheres. In this example, the molten copper could be stably obtained without getting wet to the nozzle.

It is a perspective view of the melt outflow nozzle of the embodiment of the present invention. It is a perspective view showing each inner surface and each outer surface of the melt outflow nozzle of the embodiment of the present invention. It is a longitudinal cross-sectional view of the melt outflow nozzle of embodiment of this invention. It is a top view of the melt outflow nozzle of the embodiment of the present invention. It is a top view which illustrates the variation of another shape of the melt outflow nozzle of the embodiment of the present invention. It is sectional drawing of the spherical particle shaping | molding apparatus incorporating the melt outflow nozzle of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Melt outflow nozzle 2 Tip 21 End surface 3 Outflow part 31 Inner surface 32 Outer surface 4 Inclined part 41 Second inner surface 42 Second outer surface 5 Inflow part 51 Third inner surface 52 Third outer surface 6 Flow path 7 Spherical particle forming device 8 Holding container 9 Furnace body 10 Guide path 11 Recovery means 111 Liquid A ₁ First flow path cross section a ₁ First flow path cross section

Claims (14)

In a melt outlet nozzle having a melt flow path,
An inner surface facing the flow path, an outer surface covering the inner surface, and an end surface connecting the inner surface and the outer surface at the tip,
The melt outflow nozzle, wherein a center line average roughness (Ra) of the outer surface and the end surface is 1.6 μm or less. The melt outflow nozzle according to claim 1, wherein the inner surface has a center line average roughness (Ra) of 1.6 μm or less. The melt outflow nozzle according to claim 1 or 2 , wherein at least the outer surface is made of platinum or a platinum alloy. The melt outflow nozzle according to any one of claims 1 to 3 , wherein a cross section perpendicular to the melt outflow direction of the outer surface is substantially a circle or an ellipse. The melt outflow nozzle according to any one of claims 1 to 4 , wherein the end face is perpendicular to a melt outflow direction. For the inner surface, when the cross-sectional area perpendicular and melt outflow direction is a _1, characterized in that the cross-sectional area a ₁ is 40 mm ² or less, melt stream according to any one of claims 1 to 5 Out nozzle. The melt outflow nozzle according to any one of claims 1 to 6 , wherein the inner surface has a circular cross section perpendicular to the melt outflow direction. Wherein the melt is molten glass, the melt flow nozzle according to any one of claims 1 to 7. A spherical particle forming apparatus having the melt outlet nozzle according to any one of claims 1 to 8 . A spherical glass forming apparatus having the melt outflow nozzle according to any one of claims 1 to 8 . The glass molded object shaping | molding apparatus which has a melt outflow nozzle in any one of Claim 1 to 8 . The spherical particle manufacturing method which shape | molds a molten material spherically using the spherical particle shaping | molding apparatus of Claim 9 . The spherical glass manufacturing method which shape | molds glass spherically using the spherical glass shaping | molding apparatus of Claim 10 . The glass molded object manufacturing method which manufactures a glass molded object using the glass molded object shaping | molding apparatus of Claim 11 .

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