JP2008273787A - Nozzle for discharging molten material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nozzle for discharging a molten material where the wet spread of the molten material on the nozzle can be very few when a spherical micro granule or a preform material is produced and which can be easily produced. <P>SOLUTION: The nozzle for discharging the molten material where the passage of the molten material is formed is provided with an inside surface facing to the passage, an outside surface covering the inside surface and an edge surface connecting the inside surface with the outside surface and is characterized by that angle θ<SB>1</SB>made by the edge surface appearing at the lowest part in the discharging direction of the molten material in a cross section passing the center of the passage and being parallel to the discharging direction of the molten material, and the outside surface or the inside surface is 15° or more and less than 90°. <P>COPYRIGHT: (C)2009,JPO&INPIT

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. Furthermore, semiconductor spheres such as silicon spheres are used in the field of solar cells and the like.

  Therefore, a method for producing these glass-made elements, fine metal spheres, and semiconductor 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 molten glass outflow pipe or inside the nozzle tip 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 wets on the outer surface of the nozzle, and the glass sometimes adheres in a dumpling form at the tip of the nozzle. In such a state, the molten glass could not flow out as a glass flow having a constant flow rate and a constant shape, and accurate microspheres could not be obtained.

  In Patent Documents 2 and 3, a technique for 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 the technology for manufacturing such a glass body, there are many cases where a melt flows up and adheres to the vicinity of the tip of the nozzle and 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 this devitrification mixes into the falling glass droplets, resulting in glass It was easy to cause a defect due to devitrification in the body.

  Patent Document 3 discloses an apparatus in which the outer surface of a nozzle for dropping molten glass has a substantially conical shape whose diameter of the outlet of the molten glass is increased. However, it has been difficult to form a generally conical shape for a small-diameter nozzle.

For this reason, while being able to manufacture easily, melted materials, such as glass, a metal, and a semiconductor, do not get wet and adhere, and can flow out a melt flow of constant flow and shape, such as a preform material or an optical element Development of a nozzle capable of forming spherical particles has been demanded.
JP 2003-104744 A Japanese Examined Patent Publication No. 7-51446 JP 2001-089159 A

  INDUSTRIAL APPLICABILITY The present invention is used in a method or apparatus for accurately producing a large amount of fine spherical particles or preform materials by gravity and surface tension in the process of flowing out a melt from a melt outflow nozzle and dropping the melt. In the melt outflow nozzle, a melt outflow nozzle that can greatly reduce the wetting of the melt onto the nozzle when manufacturing minute spherical particles or preform material and can be easily manufactured is provided. It is to provide.

  In order to solve the above problems, the inventors of the present invention 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 a preform material, By forming a predetermined shape with a predetermined inclination, it is easy to process, and almost no spherical wetting of the molten material or preform material can be achieved with high accuracy and almost no wetness of the molten material. The inventors have found that it can be formed in large quantities, and have completed the present invention.

  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 covering the inner surface, and an end surface connecting the inner surface and the outer surface, The angle θ ₁ formed between the end surface and the outer surface or the inner surface, which appears at the bottom of the melt outflow direction in a cross section passing through the center and parallel to the outflow direction of the melt, is 15 degrees or more and less than 90 degrees. A melt outflow nozzle characterized by the above.

(2) In a cross section passing through the center of the flow path and parallel to the outflow direction of the melt, a straight line that bisects the angle θ ₁ formed, and a curved surface connecting the end surface and the outer surface or the end surface and the inner surface The melt outflow nozzle according to (1), wherein a curvature radius at an intersection point P with the connecting curved surface is 0.05 mm or less.

(3) For the inner surface and the outer surface, when the cross-sectional areas perpendicular to the melt outflow direction are a ₁ and b ₁ , respectively, and the diameters of the circles having the same area as the cross-sectional area are d and D, respectively, The melt outflow nozzle according to (1) or (2), wherein the relationship between D and D is represented by the following formula (I):

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

(5) The melt outflow nozzle according to any one of (1) to (4), wherein the cross-sectional area a ₁ is 40 mm ² or less.

  (6) The melt outflow nozzle according to any one of (1) to (5), wherein a cross section perpendicular to the melt outflow direction of the end surface and the inner surface is a circle.

  (7) The melt outflow nozzle according to any one of (1) to (6), wherein a cross section of the outer surface perpendicular to the melt outflow direction is a circle.

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

  (9) A spherical particle forming apparatus having the melt outflow nozzle described in (1) to (8).

  (10) A spherical glass forming apparatus having the melt outflow nozzle described in (1) to (8).

  (11) A glass molded body forming apparatus having the melt outflow nozzle described in (1) to (8).

  (12) A spherical particle production method for forming a melt into a spherical shape using the spherical particle forming apparatus according to (9).

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

  (14) A glass molded body manufacturing method for manufacturing a glass molded body using the glass molded body molding apparatus according to (11).

  According to the present invention, in a melt outflow nozzle used in a method or apparatus for accurately producing a large amount of fine spherical particles or preform material, the melt to the nozzle is produced when producing the fine spherical particles or preform material. It is possible to obtain a melt outflow nozzle that can greatly reduce the wetting of an object and can be easily manufactured.

  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. The angle θ ₁ formed by the end surface and the outer surface or the inner surface, which appears at the bottom of the melt outflow direction in a cross section parallel to the outflow direction of the melt, is 15 degrees or more and less than 90 degrees. .

  The melt outflow nozzle is generally wet with the melt, although there are some differences 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 easy. If the wettability of the melt to the melt outflow nozzle is high, the melt flows around to the outer surface side of the melt outflow nozzle when the outflow of the melt starts or when the melt outflows. A phenomenon of wetting upward occurs on the outer surface of the exit nozzle. Then, the wet melted material becomes a lump at the tip of the melt outflow nozzle, making it difficult for the melt to flow out. Or when a melt is glass, devitrification will generate | occur | produce in glass by wet-up and it will become a cause which a defect generate | occur | produces in the obtained molded object. Therefore, it is necessary to prevent the melt from getting wet.

In the present invention, within the above θ less than _one angle 90 degrees of the melt flow nozzle, when starting the flow of the melt, or when performing the outflow of the melt, the bottom of the melt flow nozzle It is possible to prevent the melt from getting wet on the outer surface of the melt outflow nozzle beyond the (tip). Therefore, a glass flow having a constant flow rate and a constant shape can be stably discharged from the melt outflow nozzle.

In order to make it easier to obtain the above effect, the upper limit of θ ₁ is preferably 60 degrees or less, and most preferably 55 degrees or less. Further, if the θ ₁ is less than 15 degrees, the mechanical strength of the melt outflow nozzle becomes difficult to obtain the strength necessary for producing spherical particles or the like, so the lower limit of the θ ₁ is preferably 15 degrees, and 20 degrees Is more preferable, and 25 degrees is most preferable.

Here, a curved surface connecting the end surface and the inner surface or the outer surface, which constitutes θ ₁ , is a curved surface R. When the θ ₁ is composed of an end surface and an inner surface, the curved surface R is a curved surface connecting the end surface and the inner surface, and when the θ ₁ is composed of an end surface and an outer surface, the curved surface R connects the end surface and the outer surface. It is a curved surface.

In order to more effectively prevent wetting of the melt to the outer surface, the angle defined by θ ₁ is set to 2 etc. in a cross section passing through the center of the flow path and parallel to the outflow direction of the melt. The radius of curvature at the intersection P between the straight line to be divided and the curved surface R is preferably 0.05 mm or less, more preferably 0.01 mm or less, and most preferably 0.005 mm or less. By making the tip portion of the angle defined by θ ₁ as a curved surface with a small curvature radius as in the above range, wetting of the melt to the outer surface can be more effectively prevented.

  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.

[First embodiment]
A first embodiment in which the end surface 21 of the melt outflow nozzle 1 of the present invention is inclined toward the inner surface 31 will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view of a melt outflow nozzle 1 according to a first embodiment of the present invention, and FIG. 2 is a cross section taken along a plane parallel to the melt outflow direction and passing through the center of the melt outflow nozzle 1. It is a longitudinal cross-sectional view.

The melt outflow nozzle 1 of the first embodiment has an end surface 21 and an outer surface 32 that appear at the lowest part (tip 2) in the melt outflow direction in a cross section parallel to the outflow direction of the melt passing through the center of the flow path 6. Is formed such that the angle θ ₁ (see FIG. 2) is 15 degrees or more and less than 90 degrees.

As shown in FIGS. 1 and 2, the melt outflow nozzle 1 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. The end surface 21 is inclined toward the inner surface 31, and the channel cross-sectional area of the inclined portion is expanded toward the tip 2. Furthermore, it is composed of an outflow portion 3 that flows out the melt, an inclined portion 4 that continues to the outflow portion 3, and an inflow portion 5 that flows in the melt that continues to the inclined portion 4. It is a cylindrical melt outflow nozzle 1 in which a channel 6 is formed, and the shape of the flow path 6 is continuous with the inner surface 31 located on the outflow side of the melt and the inner surface 31, and the first flow path cross-sectional area a second inner surface 41 that changes from a ₁ to a _second channel cross-sectional area a _2, and a third inner surface 51 that is continuous with the second inner surface 41 and has a _second channel cross-sectional area a _2. 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 in the present embodiment refers to a surface that faces the channel 6 of the melt outflow nozzle 1 that appears in a vertical cross section in the melt outflow direction (in this embodiment, the end surface 21, the inner surface 31, the second inner surface). 41 and the surface surrounded by the third inner surface 51), and 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. ₁ ) in the portion of the inner surface 31 that appears in the vertical cross section in the melt outflow direction (arrow direction in FIG. 2). The second flow path cross-sectional area a ₂ means the area of the flow path cross section (A _{2 in} FIG. 1) 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 cross-section b ₂ , a second outer surface 42 that changes, and a third outer surface 52 that is continuous with the second outer surface 42 and has a second outer cross-sectional area b _2. 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 in the present embodiment is surrounded by the outer shapes of the melt outflow nozzle 1 (in this embodiment, the outer surface 32, the second outer surface 42, and the third outer surface 52) appearing in the vertical cross section in the melt outflow direction. It means a surface, and the outer cross-sectional area means the area of such outer cross-section. The first outer cross-sectional area b ₁ means the area of a cross section (B _{1 in} FIG. ₁ ) surrounded by the outer shape of the melt outflow nozzle 1 that appears 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. 1) surrounded by the outer shape of the melt outflow nozzle 1 appearing in the vertical cross section of the second outer surface 42 in the melt outflow direction.

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. In addition, the amount of material used for the melt outflow nozzle 1 is not wasted, and the outflow shape of the melt immediately after flowing out from the outflow port of the melt outflow nozzle 1 tends to be cylindrical, From the standpoint that it is easy to obtain a substantially elliptical shaped body, the cross section of the flow path at the positions of the end surface 21 and the inner surface 31 or the outer cross section of the position of the outer surface 32 is more preferably circular. Furthermore, the melt outflow nozzle 1 has no unevenness, and the cross section of the flow path and the outer cross section are concentric. The temperature distribution of the melt in the vicinity of the melt outflow nozzle 1 tends to be uniform, and the molding is uniform. The body is most preferable because it is easy to obtain.

When the diameter of a circle equal to the channel cross-sectional area a ₁ in the inner surface 31 portion of the melt outflow nozzle 1 is d and the diameter of the circle equal to the outer cross-sectional area b ₁ in the outer surface 32 portion is D, the diameter d The diameter D preferably satisfies the value of the following formula (1).

  Here, when the flow path cross section and the outer cross section at the tip 2 of the outflow portion 3 are respectively circular, the diameter d and the diameter D are the diameters of the flow path cross section and the outer cross section at the tip 2 of the outflow section 3, respectively. .

  If the diameter D satisfies the value of the above formula (1), the inner surface 31 of the melt outflow nozzle 1 can be easily processed with high accuracy, and the strength of the outflow portion 3 can be sufficiently increased. Moreover, the thickness of the outflow part 3 becomes thin, and it becomes easier to suppress the wetting of the melt to the outer surface 32.

  In order to increase the strength of the melt outflow nozzle 1 and facilitate high-precision processing, the upper limit of the d / D value is more preferably 0.88 or less, and the d / D is 0.85 or less. Most preferred. Further, in order to more easily suppress the rise of the melt to the outer surface 32, the lower limit of the d / D value is more preferably 0.5 or more, and most preferably 0.55 or more.

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, preferably 3.5 mm ² or less if the diameter shaping the spherical particles or preform material below 2.5 mm. If the size of the flow path cross-sectional area a ₁ is within this range, it can be preferably used for the production of spherical particles or preform material.

  In addition, the cross-sectional shape which cut | disconnected the melt outflow nozzle 1 in the orthogonal | vertical direction with respect to the melt outflow direction is not specified circularly like this 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, or a desorption function between the guide path and the melt outflow nozzle 1. May be used by being mounted on a taxiway.

  As a specific example, the tip of the surface on which the outlet of the guide path is formed and the inflow portion 5 of the melt outflow nozzle 1 are brought into close contact so that the outlet and the inlet are connected, and means such as screwing Attach with or weld. At this time, if the close contact is not properly made, the melt enters between the leading end of the guide path and the melt outflow nozzle 1, and the melt leaks out from the melt outflow nozzle 1. It is necessary to adhere to at least 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 with a size close to a predetermined hole diameter in 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 end portion and the outer surface of the material are cut into a predetermined shape, and the melt outflow nozzle 1 having the end surface 21 having a desired shape is manufactured. The method for producing the melt outflow nozzle 1 is an example, and the melt outflow nozzle 1 having the end face 21 inclined at a desired angle may be produced by another method.

[Second Embodiment]
Next, a second embodiment in which the end surface 21 of the melt outflow nozzle 1 of the present invention is inclined toward the outer surface 32 will be described with reference to FIGS. 4 and 5. FIG. 4 is a perspective view of the melt outflow nozzle 1 according to the second embodiment of the present invention, and FIG. 5 is a cross section taken along a plane parallel to the melt outflow direction and passing through the center of the melt outflow nozzle 1. It is a longitudinal cross-sectional view. In addition, about the location which overlaps with 1st embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted suitably.

The melt outflow nozzle 1 of the second embodiment has an end surface 21 and an inner surface 31 that appear at the bottom (tip 2) in the melt outflow direction in a cross section parallel to the outflow direction of the melt passing through the center of the flow path 6. Is formed such that the angle θ ₁ (see FIG. 5) is 15 degrees or more and less than 90 degrees.

As shown in FIGS. 4 and 5, the second 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. The end surface 21 is inclined toward the outer surface 32, and the outer cross-sectional area of the inclined portion is narrowed toward the tip 2. Furthermore, it is composed of an outflow portion 3 that flows out the melt, an inclined portion 4 that continues to the outflow portion 3, and an inflow portion 5 that flows in the melt that continues to the inclined portion 4. It is a cylindrical melt outflow nozzle 1 in which a channel 6 is formed, and the shape of the flow path 6 is continuous with the inner surface 31 located on the outflow side of the melt and the inner surface 31, and the first flow path cross-sectional area a second inner surface 41 that changes from a ₁ to a _second channel cross-sectional area a _2, and a third inner surface 51 that is continuous with the second inner surface 41 and has a _second channel cross-sectional area a _2. and exhibits a first flow path cross-sectional area a ₁ second flow channel shape larger cross-sectional area a ₂ than.

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 and it has a first outer cross-sectional area b ₁ smaller shape than the cross-sectional area b _2.

Here, the cross section of the flow path in the present embodiment is a surface facing the flow path 6 of the melt outflow nozzle 1 appearing in a vertical cross section in the melt outflow direction (in this embodiment, the inner surface 31, the second inner surface 41, and the first It means the surface surrounded by the three inner surfaces 51), and the channel cross-sectional area means the area of such channel cross-section. The outer cross section in the present embodiment is the outer shape of the melt outflow nozzle 1 that appears in the vertical cross section in the melt outflow direction (in the present embodiment, the end surface 21, the outer surface 32, the second outer surface 42, and the third outer surface 52). It means the surface to be surrounded, and the outer cross-sectional area means the area of such outer cross-section. The first channel sectional area a ₁ , the second channel sectional area a ₂ , the first outer sectional area b ₁ , and the second outer sectional area b ₂ are the same as those in the first embodiment. Therefore, explanation is omitted here.

Further, the shape of the flow passage cross sections A ₁ , A ₂ of the flow passage 6 of the melt outflow nozzle 1 and the outer cross sectional shapes B ₁ , B ₂ , B ₃ are also particularly similar to the first embodiment. Although not limited, it is preferable that the shape is similar at all positions from the viewpoint of ease of processing, the strength of the melt outflow nozzle 1, and the reduction in disturbance of the flow of the melt. More preferably. In addition, the amount of material used for the melt outflow nozzle 1 is not wasted, and the outflow shape of the melt immediately after flowing out from the outflow port of the melt outflow nozzle 1 is likely to be a columnar shape. From the viewpoint of easily obtaining an elliptical spherical molded body, the flow path cross section at the positions of the end face 21 and the inner face 31 or the outer cross section at the positions of the end face 21 and the outer face 32 is more preferably circular. Furthermore, the melt outflow nozzle 1 is free from uneven thickness, and the flow path cross section and the outer shape cross section are concentric, so that the temperature distribution of the melt in the vicinity of the melt outflow nozzle 1 tends to be uniform, and a uniform molded body is obtained. Most preferable because it is easy to obtain.

Regarding the diameter d of the circle equal to the flow path cross-sectional area a ₁ in the inner surface 31 portion and the diameter D of the circle equal to the outer cross-sectional area b ₁ in the outer surface 32 portion, the same dimensions and relationships as in the first embodiment. Since this is the same, the description is omitted here.

Since the size of the channel cross-sectional area a ₁ in the portion of the inner surface 31 of the melt flow nozzle 1 is the same as the first embodiment, the description thereof is omitted here.

  Similar to the first embodiment, the second inner surface 41 and the second outer surface 42 have a shape in which the flow path cross-sectional area is reduced and reduced from the inflow side to the outflow side of the melt. Since it is the same as that of embodiment, description is abbreviate | omitted here similarly.

[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.

  Examples of the fine spherical particles or preform material obtained by cooling the melt include glass spheres, semiconductor spheres, and metal spheres. Among these, glass spheres can be used as, for example, various optical elements, optical fibers, semiconductor laser imaging elements, and mold press optical materials. Moreover, a semiconductor sphere (for example, silicon sphere) can be used as a solar cell of a solar cell, for example. Metal balls (for example, solder balls and copper balls) can be used as, for example, micro soldering, fine ball bearings, or connection terminals of semiconductor packages.

[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.

<Production of melt outflow nozzle>
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 end portion and the outer surface of this material were cut and polished into a predetermined outer surface shape to obtain a melt outflow nozzle having an end surface inclined at a desired angle. Here, the measurement of the inclination angle of the end face of the melt outflow nozzle is performed by extracting a melt outflow nozzle produced under the same conditions and polishing it so that a cross section of the extracted melt outflow nozzle appears. Measurement was performed using iNEXIV VMA-2520 (Nikon).

The produced nozzle has a concentric circle in the cross section of the flow path and an outer cross section, and has an end surface inclined toward the inner surface, and in a cross section parallel to the flow direction of the melt passing through the center of the flow path, The angle θ ₁ formed between the end surface and the outer surface that appears at the bottom is 45 degrees. The radius of curvature at the intersection P between the straight line that bisects θ ₁ and the curved surface R was 0.004 mm. The size of the channel cross-sectional area was 0.52 mm ² and d / D was 0.81.

<Comparative example>
The angle of curvature θ ₁ formed between the lowermost end surface in the melt outflow direction and the outer surface is 90 degrees, and the radius of curvature at the intersection P between the straight line that bisects θ ₁ and the curved surface R is 0.06 mm. A melt outflow nozzle was obtained by processing in the same manner as in the example except for the above.

<Evaluation>
The melt outflow nozzle thus obtained was installed in a spherical particle forming apparatus. The wettability at the start of outflow, the stability at the start of outflow, and the stability during outflow 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 flow 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. About these evaluation items, the outflow of glass was evaluated 20 times, and the results are shown in Table 1 below.

  From the above examples, it was proved that the melt outflow nozzle of the present invention has very little wetting of the melt into the nozzle.

<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 outlet 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 above conditions flows down as a continuous flow from the tip of the nozzle to about 10 mm below, and below that, it changes into a droplet-like glass lump arranged in a row. , Dropped 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, silicon spheroids could be obtained stably without 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 the present Example, the copper spherical body was able to be acquired stably, without molten copper getting wet to a nozzle.

It is a perspective view of the melt outflow nozzle of a first embodiment of the present invention. It is a longitudinal cross-sectional view of the melt outflow nozzle of 1st embodiment of this invention. It is a top view which illustrates the variation of another shape of the melt outflow nozzle of said 1st embodiment. It is a perspective view of the melt outflow nozzle of 2nd embodiment of this invention. It is a longitudinal cross-sectional view of the melt outflow nozzle of 2nd embodiment of this 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 ₂ Second flow path cross section B ₁ First external cross section B ₂ Second external cross section a ₁ First flow path cross section a ₂ Second cross-sectional area b ₁ First external cross-sectional area b ₂ Second external cross-sectional area

Claims (14)

In the melt outlet nozzle that forms the flow path of the melt,
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,
An angle θ ₁ formed between the end surface and the outer surface or the inner surface, which appears at the lowermost portion in the melt outflow direction in a cross-section parallel to the outflow direction of the melt through the center of the flow path, is 15 degrees or more and less than 90 degrees. A melt outflow nozzle, characterized in that In a cross section passing through the center of the flow path and parallel to the outflow direction of the melt,
A radius of curvature at an intersection point P between a straight line that bisects the angle θ ₁ formed and a curved surface that connects the end surface and the outer surface or a curved surface that connects the end surface and the inner surface is 0.05 mm or less. Item 2. The melt outlet nozzle according to Item 1. As for the inner surface and the outer surface, when the cross-sectional areas perpendicular to the melt outflow direction are a ₁ and b ₁ , respectively, and the diameters of the circles having the same area as the cross-sectional area are d and D, respectively, The melt outflow nozzle according to claim 1, wherein the relationship is a relationship of the following mathematical formula (I).

  The melt outflow nozzle according to any one of claims 1 to 3, wherein at least the end face is made of platinum or a platinum alloy. Wherein the cross-sectional area a ₁ is 40 mm ² or less, the melt flow nozzle according to any one of claims 1 to 4.   The melt outflow nozzle according to any one of claims 1 to 5, wherein a cross section perpendicular to a melt outflow direction about the end face and the inner surface is a circle.   The melt outflow nozzle according to any one of claims 1 to 6, wherein a cross section of the outer surface perpendicular to the melt outflow direction is a circle.   The melt outflow nozzle according to claim 1, wherein the melt is a molten glass.   A spherical particle forming apparatus having the melt outflow nozzle according to claim 1.   The spherical glass shaping | molding apparatus which has a melt outflow nozzle of Claim 1-8.   The glass molded object shaping | molding apparatus which has a melt outflow nozzle of Claim 1-8.   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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