JP3990953B2 - Composite spinning nozzle and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a composite spinning nozzle used for manufacturing an optical transmission body such as an optical fiber and a rod lens, and a manufacturing method thereof.
[0002]
[Prior art]
The compound spinning nozzle is used for manufacturing an optical transmission body such as a plastic optical fiber or a plastic rod lens having a refractive index distribution in which the refractive index decreases from the central portion toward the outer peripheral portion. This composite spinning nozzle is composed of a plurality of single-layer nozzles, and by using this composite spinning nozzle, a plurality of solutions or molten raw materials are arranged in such an arrangement that the refractive index after curing gradually decreases from the central portion toward the outer peripheral portion. (Hereinafter referred to as “stock solution”) can be laminated in a concentric cylindrical shape and shaped (spun) into a yarn shape.
[0003]
FIG. 1 shows the structure of a composite spinning nozzle composed of a plurality of single-layer nozzles. Each single-layer nozzle is arranged and fixed so that the nozzle hole center point in the vertical plane of the nozzle hole is located on the coaxial line. Yes. FIG. 1A is a plan view of the composite spinning nozzle as viewed from the discharge side opening 110 side of the stock solution, and FIG. 1B is a cross-sectional view. Further, the first layer single layer nozzle 101 supplies and discharges a stock solution for forming a central layer (first layer) of the cylindrical laminated structure of the filamentous body to be shaped, and the second layer single layer nozzle 102 A stock solution for forming a second layer around one layer is supplied and discharged. A flow path of the stock solution that passes through the center of each single-layer nozzle and reaches the discharge-side opening 110 is a nozzle hole.
[0004]
In FIG. 1, only the first layer single layer nozzle 101 and the second layer single layer nozzle 102 are shown, but the third layer and subsequent single layer nozzles are further arranged on the second layer single layer nozzle 102. In some cases. Further, in FIG. 1, the filamentous body is shaped while discharging the stock solution from the lower side to the upper side of the drawing. However, when the entire composite spinning nozzle is used in a direction different from that in FIG. There is also.
[0005]
After the filament formed using such a composite spinning nozzle is cured, an optical transmission body can be obtained by subjecting it to a stretching treatment or a heat treatment as necessary. In the above-described composite spinning nozzle, the center point of the nozzle hole (hereinafter referred to as “nozzle hole center point”) in a plane perpendicular to the nozzle hole longitudinal direction of each single-layer nozzle constituting the nozzle is positioned as coaxial as possible. That is, it is required that the nozzle hole has high coaxiality. When the coaxiality of the nozzle hole is low, the composition distribution and shape in the cross-sectional direction of the obtained optical transmission body may fluctuate or decenter, which may impair the optical characteristics of the optical transmission body.
[0006]
As an example, a case of a plastic rod lens used for a copying machine, a facsimile, a sensor part of a scanner, a writing device of an LED printer, or the like will be described. In the production of this plastic rod lens, a plurality of stock solutions are arranged using a compound spinning nozzle so that the refractive index after curing gradually decreases from the center to the outer periphery, and the plurality of stock solutions are concentric. By forming a thread-like body (precursor of plastic rod lens) having a cylindrically laminated structure, and by mutually diffusing each layer component to the adjacent layer, the refractive index is continuous from the center to the outer periphery. A refractive index distribution structure that decreases as a result is formed. A rod lens with such a refractive index distribution structure allows light incident from one end face to be propagated to the other end face while drawing a sinusoidal curve so that an image can be accurately formed on the image plane ahead. And can exhibit high optical performance.
[0007]
When manufacturing such a plastic rod lens, the coaxiality of the nozzle hole of the composite spinning nozzle affects the center axis accuracy of the refractive index distribution in the cross-sectional direction of the rod lens finally obtained, that is, the optical axis accuracy. It easily affects the optical performance of plastic rod lenses that require precise control of the refractive index distribution. Therefore, high nozzle hole coaxiality is required for a composite spinning nozzle used for shaping a filamentous body.
[0008]
As a conventional composite spinning nozzle, one that fixes each single-layer nozzle with pins or bolts has been used. For example, in FIG. 1, each single-layer nozzle includes a knock pin 103, and the single-layer nozzle can be fixed by fitting the knock pin 103 into the fitting portion 104 of another single-layer nozzle.
[0009]
[Problems to be solved by the invention]
However, in the conventional composite spinning nozzle, the position of the structure part serving as a reference for the fixed position of each single-layer nozzle is limited by the limit of the processing accuracy of the machine tool itself used for processing each single-layer nozzle or the human error of the operator. It was inevitable that the accuracy would have some deviation from the design value. In particular, in the single-layer nozzle fixing structure as shown in FIG. 1, the position of the structure portion (such as the center point of the knock pin 103 or the knock pin fitting portion 104) serving as a reference for the fixing position of each single-layer nozzle and its design value If there is a gap between the nozzles, even if there is a slight gap (for example, about several μm) per single layer nozzle, when they are assembled into a composite spinning nozzle, the size cannot be ignored (for example, several tens of micrometers). [mu] m), and this is directly reflected in the coaxiality of the nozzle hole as a composite spinning nozzle. The problem of such coaxial shift becomes more serious as the number of single-layer nozzles constituting the composite spinning nozzle increases, and the cumulative value of shift increases.
[0010]
Thus, even if the conventional composite spinning nozzle is designed so that the nozzle hole center point of each single layer nozzle is located on the coaxial line, each center point from the coaxial line is actually It was not uncommon to deviate by several tens of micrometers or more.
[0011]
Accordingly, an object of the present invention is a composite spinning nozzle composed of a plurality of single-layer nozzles suitable for the manufacture of an optical transmission body having a refractive index distribution from the center in the cross-sectional direction to the outer peripheral portion, and has a high coaxial nozzle hole. An object of the present invention is to provide a composite spinning nozzle having properties.
[0012]
[Means for Solving the Problems]
In view of the above-mentioned problems, the inventors of the present invention focused on processing individual raw material blocks for each single-layer nozzle, and as a result of intensive studies, the present invention was completed.
[0013]
That is, the present invention is a composite spinning nozzle in which a plurality of single-layer nozzles are stacked and combined so that the central axis of the nozzle hole is located on the coaxial line,
The joint between the two single-layer nozzles to be joined to each other has a fitting portion provided on the joint-side outer circumference of one single-layer nozzle and the joint-side outer circumference of the other single-layer nozzle,
In the fitting portion, the two single-layer nozzles to be joined are fixed by a fixing jig that applies an equal force in the center direction of the nozzle hole .
[0014]
Further, according to the present invention, the fitting recess is formed by a stepped portion provided on the joining side outer periphery of one single layer nozzle and a stepped portion provided on the joining side outer periphery of the other single layer nozzle. It is related with said composite spinning nozzle characterized by these.
[0015]
In the invention, it is preferable that the fixing jig has support portions that are in contact with both step portions of the two single-layer nozzles forming the fitting concave portions at three or more locations on the inner peripheral surface thereof. This relates to a composite spinning nozzle.
[0016]
The present invention also relates to any one of the above composite spinning nozzles, wherein the fixing jig is cylindrical.
[0017]
Further, the present invention is a method for producing the above composite spinning nozzle,
The present invention relates to a method for producing a composite spinning nozzle, wherein at least two of the single-layer nozzles constituting the composite spinning nozzle are produced by processing one raw material block.
[0018]
Further, the present invention is a method for producing the above composite spinning nozzle,
Preparing a raw material block having a size capable of forming at least two of the single-layer nozzles constituting the composite spinning nozzle;
Forming the recess corresponding to the fitting recess on the outer periphery while rotating the raw material block;
The present invention relates to a method for manufacturing a composite spinning nozzle, which includes a step of cutting the raw material block in the concave portion to form at least two of the single-layer nozzles constituting the composite spinning nozzle.
[0019]
The present invention also relates to the above-described method for producing a composite spinning nozzle, comprising a step of opening a hole that becomes a nozzle hole along the rotation axis while rotating the raw material block before the cutting step.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described.
[0021]
An outline of the structure of one embodiment of the composite spinning nozzle of the present invention is shown in FIG. 2A is a plan view seen from the discharge side opening 20 side of the stock solution, and FIG. 2B is a cross-sectional view.
[0022]
This embodiment shown in FIG. 2 is a single-hole five-layer type composite spinning nozzle (compound spinning nozzle composed of five single-layer nozzles and capable of forming one filament by combining five types of stock solutions). This is an example.
[0023]
Reference numeral 1 denotes a first-layer single-layer nozzle that supplies and discharges a stock solution for forming a central layer (first layer) of a cylindrical laminated structure of shaped filaments. Reference numeral 2 denotes a first layer around the first layer. A second-layer single-layer nozzle that supplies and discharges a stock solution that forms two layers. Reference numeral 3 denotes a third-layer single-layer nozzle that supplies and discharges a stock solution that forms a third layer around the second layer. Reference numeral 4 denotes a fourth-layer single-layer nozzle that supplies and discharges a stock solution that forms the fourth layer around the third layer. Reference number 5 supplies and discharges a stock solution that forms the fifth layer around the fourth layer. This is a fifth layer single layer nozzle. The flow path of the stock solution that passes through the center of each single-layer nozzle and reaches the discharge-side opening 20 is a nozzle hole.
[0024]
In FIG. 2, the filamentous body is shaped while discharging the stock solution from the lower side to the upper side of the drawing, but there is no particular limitation on the direction of the composite spinning nozzle in use.
[0025]
Reference numerals 11, 12, 13, and 14 denote cylindrical fixing jigs (hereinafter referred to as “cylindrical jigs”) used to fix the single-layer nozzles and assemble them into composite spinning nozzles. Reference numeral 11 is a cylindrical jig for fixing the first layer single layer nozzle and the second layer single layer nozzle, and reference numeral 12 is a cylinder for fixing the second layer single layer nozzle and the third layer single layer nozzle. Reference numeral 13 denotes a cylindrical jig for fixing the third layer single layer nozzle and the fourth layer single layer nozzle, and reference numeral 14 denotes a fourth layer single layer nozzle and a fifth layer single layer nozzle. It is a cylindrical jig for fixing.
[0026]
FIG. 3 is a sectional view of the composite spinning nozzle in a state where all the cylindrical jigs 11 to 14 are removed from the structure shown in FIG.
[0027]
Reference numerals 21, 22, 23 and 24 are concave fitting portions (hereinafter referred to as “fitting concave portions”) for attaching the cylindrical jigs 11 to 14, respectively.
[0028]
Reference numeral 21A denotes a stepped portion of the first layer single-layer nozzle, and reference numeral 21B denotes a stepped portion of the second-layer single-layer nozzle, and the fitting recess 21 is formed by the stepped portions 21A and 21B. . Reference numeral 22A denotes a step portion of the second layer single-layer nozzle, and reference numeral 22B denotes a step portion of the third layer single-layer nozzle. The step portions 22A and 22B form a fitting recess 22. Reference numeral 23A denotes a stepped portion of the third-layer single-layer nozzle, and reference numeral 23B denotes a stepped portion of the fourth-layer single-layer nozzle. A recess 23 for fitting is formed by the stepped portions 23A and 23B. Reference numeral 24A denotes a step portion of the fourth layer single-layer nozzle, and reference numeral 24B denotes a step portion of the fifth layer single-layer nozzle. The structure portions 24A and 24B form a fitting recess 24.
[0029]
As shown in FIGS. 2 and 3, each of the cylindrical jigs described above is fitted into a fitting recess formed by a step portion of the upper single layer nozzle and a step portion of the lower single layer nozzle. That is, it is attached so as to be sandwiched between the single-layer nozzle on the upper layer side and the single-layer nozzle on the lower layer side, and the two single-layer nozzles on the upper layer side and the lower layer side can be fixed.
[0030]
As described above, the composite spinning nozzle of the present invention fixes the single-layer nozzles using the cylindrical jig as described above in place of the structure portion serving as a fixing position reference such as a conventional pin or bolt. Since the fixing structure (cylindrical jig and fitting recess) in the present invention can adopt the manufacturing method described later, the nozzle hole has a coaxiality compared to the fixing structure (pins, bolts, etc.) in the prior art. Can be increased.
[0031]
In the present invention, the fitting portion is not limited to a concave shape, and may be, for example, a convex shape. However, when using a method for manufacturing a composite spinning nozzle described later, the nozzle hole is easily combined with high coaxiality. Since a spinning nozzle can be manufactured, a concave shape is preferable. When making a fitting part convex, as a fixing jig, what has a crevice which can be fitted in a fitting part can be used, for example. Further, in the present invention, the fixing jig is not limited to a cylindrical one, but the single-layer nozzle can be firmly fixed while maintaining the coaxiality of the nozzle hole, and because it is easy to manufacture, the cylindrical one is Is preferred.
[0032]
In this embodiment, all the single-layer nozzles constituting the composite spinning nozzle are fixed by fitting a cylindrical jig into the fitting recess, and such a fixed structure is used for some single-layer nozzles. It is also possible to use other methods for fixing between the other single-layer nozzles.
[0033]
Hereinafter, the method for producing the composite spinning nozzle of the present invention will be described with reference to FIG.
[0034]
First, one columnar raw material block having a size capable of processing all the single-layer nozzles constituting the composite spinning nozzle of the present invention is prepared (FIG. 4A).
[0035]
Next, the recesses 31, 32, 33 and 34, which are the recesses for fitting for mounting the cylindrical jig, are cut on the outer periphery of the raw material block using a cutting machine tool such as a lathe (see FIG. 4 (b)). The concave portions are formed in a number corresponding to the number of single-layer nozzles to be manufactured (one smaller than the number of single-layer nozzles).
[0036]
In FIG. 4B, the recess 31 corresponds to the fitting recess 21 (steps 21A and 21B) for fixing the first layer single-layer nozzle and the second layer single-layer nozzle, and the recess 32 is the second Corresponding to the fitting recess 22 (steps 22A and 22B) for fixing the single layer nozzle and the third single layer nozzle, the recess 33 fixes the third single layer nozzle and the fourth single layer nozzle. Corresponding to the fitting recess 23 (steps 23A and 23B), and the recess 34 is the fitting recess 24 (steps 24A and 24B) for fixing the fourth layer single layer nozzle and the fifth layer single layer nozzle. It corresponds to.
[0037]
In the manufacturing method of the present invention, the raw material block itself is rotated with its central axis as the rotation axis Z (direction g in FIG. 4 (b) or the opposite direction), while the recesses 31, 32, 33, 34 are provided. Is preferably formed by processing. Thereby, in each finally obtained single-layer nozzle, the contour center point of the stepped portion (the center point of the contoured portion of the stepped portion in the XY plane perpendicular to the rotation axis Z) serving as a position reference for fixing by the cylindrical jig is obtained. , All can be precisely matched to Z on the rotation axis during processing.
[0038]
Furthermore, in the case of a single hole type composite spinning nozzle, it is desirable to open the hole 30 as a nozzle hole simultaneously while rotating the raw material block. Thereby, the center of the outer shape of the step portion of each single-layer nozzle that forms the fitting recess for attaching the cylindrical jig and the center axis of the nozzle hole can be easily aligned on the rotation axis Z at the time of processing. .
[0039]
Finally, as shown in FIG.4 (c), the raw material block which gave said process is divided | segmented by each recessed part 31-34 using cutting machine tools, such as a wire cutter, and a detailed process, finishing, etc. To complete each single-layer nozzle 1-5.
[0040]
The member 1 in FIG. 4C corresponds to the first layer single layer nozzle 1 in FIG. 2B, and the member 2 in FIG. 4C corresponds to the second layer single layer nozzle 2 in FIG. 4C corresponds to the third-layer single-layer nozzle 3 in FIG. 2B, and the member 4 in FIG. 4C corresponds to the fourth-layer single-layer nozzle 4 in FIG. 2B. Correspondingly, the member 5 in FIG. 4C corresponds to the fifth single-layer nozzle 5 in FIG.
[0041]
Each single-layer nozzle according to the prior art is manufactured by processing an individual raw material block for each single-layer nozzle, whereas in the manufacturing method of the present invention, a single raw material block is divided into single layers. All of the nozzles are manufactured, and at that time, all of the step portions of each single-layer nozzle forming the fitting recess for attaching the cylindrical jig are formed at the stage of the raw material block (before division processing). Therefore, deviation of the fixed position reference (stepped portion) of each single-layer nozzle finally obtained can be suppressed, and the coaxiality of the nozzle hole can be enhanced.
[0042]
The material of the raw material block is not particularly limited, but it is preferable to use a stainless steel material (SUS) in consideration of strength, corrosion resistance, workability, cost, and the like.
[0043]
In the present embodiment, the stepped portion corresponding to the fitting recess for attaching the completed cylindrical jig of each single-layer nozzle is formed by processing while rotating the raw material block. The cross-sectional shape perpendicular to the rotation axis direction Z is circular, but the other portions are not limited to a circular cross-sectional shape, and may be any shape such as a triangle, a quadrangle, or a higher polygon. can do. In addition, when the step portion is formed using another method, the step portion can have another shape. Moreover, when making a fitting part into a convex shape, for example, a fitting part can be formed by cutting parts other than a fitting part, rotating a raw material block.
[0044]
Further, the present invention has been described by exemplifying a single-hole type composite spinning nozzle. However, the present invention is not limited to a porous type composite spinning nozzle (a single-layer nozzle for one layer has a plurality of nozzle holes and a plurality of nozzle holes in one set). The present invention can also be applied to a composite spinning nozzle capable of shaping a filamentous body of a book and a manufacturing method thereof. When forming a plurality of nozzle holes, for example, in the stage before dividing the raw material block, the raw material block may be separately processed before or after the concave portion corresponding to the concave portion for fitting is processed.
[0045]
Further, the number of single layer nozzles constituting one composite spinning nozzle is not particularly limited.
[0046]
In order to assemble each single-layer nozzle produced as described above as a composite spinning nozzle, a cylindrical jig as shown in FIG. 5 can be used. Fig.5 (a) is a top view of the said cylindrical jig | tool, FIG.5 (b) is a side view.
[0047]
The cylindrical jig in FIG. 5 corresponds to the members indicated by reference numerals 11 to 14 in FIG.
[0048]
Each cylindrical jig has support portions 41, 42, and 43 for fixing two single-layer nozzles on its inner peripheral surface. These support portions are in contact with the step portions (21A and 21B, 22A and 22B, 23A and 23B, or 24A and 24B) of the single-layer nozzles that form recesses for fitting for attaching the cylindrical jig. Fix between single layer nozzles.
[0049]
The cylindrical jig illustrated in FIG. 5 has a circular shape on both the outer peripheral side and the inner peripheral side, but has a circular shape as long as it has a support portion for contacting and fixing the step portion of each single-layer nozzle. There is no limitation, and both the outer peripheral side and the inner peripheral side may be triangular, quadrangular, or more polygonal or arbitrary shapes, and the shapes of the outer peripheral side and the inner peripheral side may be different.
[0050]
The cylindrical jig of the present invention has at least three support portions for fixing between the single-layer nozzles on its inner peripheral surface, and there is no upper limit on the number of nozzles, although there is no upper limit. The number of contact points between the support portion and each single-layer nozzle should be small in order to give a uniform force in the direction of the center 40 of the nozzle and make it easier to arrange the central axis of each single-layer nozzle coaxially. . Further, it is preferable that the support portions are arranged at equiangular intervals in the direction viewed from the center 40 of the nozzle. In the example shown in FIG. 5, support portions are formed at three locations at equal intervals of a central angle of 120 ° on the inner peripheral surface of the cylindrical jig.
[0051]
In addition, although the material of said cylindrical jig | tool is not specifically limited, In consideration of intensity | strength, corrosion resistance, workability, cost, etc., it is preferable to use a stainless steel material (SUS).
[0052]
In this embodiment, all the single-layer nozzles are manufactured by processing one raw material block, but a plurality of single-layer nozzles manufactured by such a method and single-layer nozzles manufactured by other methods are used. It is also possible to manufacture a composite spinning nozzle by combining the above.
[0053]
【The invention's effect】
According to the present invention, a composite spinning nozzle having high coaxiality of nozzle holes can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic view of a conventional composite spinning nozzle.
FIG. 2 is a schematic view of a composite spinning nozzle of the present invention.
FIG. 3 is a schematic sectional view showing a state where a cylindrical jig is not attached to the composite spinning nozzle of the present invention.
FIG. 4 is a schematic view for explaining a method for producing a composite spinning nozzle of the present invention.
FIG. 5 is a schematic view showing a cylindrical jig constituting the composite spinning nozzle of the present invention.
[Explanation of symbols]
101: First layer single layer nozzle 102: Second layer single layer nozzle 103: Knock pin 104: Knock pin insertion portion 110: Nozzle hole discharge side opening 1: First layer single layer nozzle 2: Second layer single layer nozzle 3: First Three-layer single-layer nozzle 4: Fourth-layer single-layer nozzle 5: Fifth-layer single-layer nozzle 11: Cylindrical jig 12 for fixing the first-layer single-layer nozzle and the second-layer single-layer nozzle 12: Second-layer single A cylindrical jig 13 for fixing the layer nozzle and the third layer single layer nozzle: a cylindrical jig 14 for fixing the third layer single layer nozzle and the fourth layer single layer nozzle: the fourth layer single layer nozzle and the third layer single layer nozzle Cylindrical jig 20 for fixing the five-layer single-layer nozzle: Nozzle hole discharge side openings 21, 22, 23, 24: Fitting recesses 21A and 21B for attaching the cylindrical jigs: Fitting recesses 21 are formed. Stepped portions 22A and 22B: Stepped portions 23A and 23B forming recessed portions 22 for fitting: For fitting Step portions 24A, 24B forming the portion 23: Step portions 30 forming the fitting recess 24: Holes 31, 32, 33, 34 provided in the raw material block before division: Provided in the raw material block before division Recess 40: Nozzle hole center 41, 42, 43: Support provided on the inner peripheral surface of the cylindrical jig

Claims (7)

A plurality of single-layer nozzles are composite spinning nozzles that are stacked and combined such that the central axis of the nozzle hole is positioned on the coaxial line,
The joint between the two single-layer nozzles to be joined to each other has a fitting portion provided on the joint-side outer circumference of one single-layer nozzle and the joint-side outer circumference of the other single-layer nozzle,
In the fitting portion, two single-layer nozzles to be joined are fixed by a fixing jig that applies an equal force in the center direction of the nozzle hole .   The fitting portion is a fitting recess formed by a stepped portion provided on the joining side outer periphery of one single layer nozzle and a stepped portion provided on the joining side outer periphery of the other single layer nozzle. The composite spinning nozzle according to claim 1.   The said fixing jig has a support part which contacts the both level | step-difference part of the two single layer nozzles which form the said recessed part for fitting in three or more places of the internal peripheral surface of Claim 2 characterized by the above-mentioned. Composite spinning nozzle.   The composite spinning nozzle according to any one of claims 1 to 3, wherein the fixing jig is cylindrical. A method for producing a composite spinning nozzle according to any one of claims 1 to 4,
A method for producing a composite spinning nozzle, wherein at least two of the single-layer nozzles constituting the composite spinning nozzle are produced by processing one raw material block. A method for producing a composite spinning nozzle according to claim 2 or 3,
Preparing a raw material block having a size capable of forming at least two of the single-layer nozzles constituting the composite spinning nozzle;
Forming the recess corresponding to the fitting recess on the outer periphery while rotating the raw material block;
A method for producing a composite spinning nozzle, comprising the step of cutting the raw material block at the concave portion to form at least two of the single-layer nozzles constituting the composite spinning nozzle.   The method for producing a composite spinning nozzle according to claim 6, further comprising a step of opening a hole serving as a nozzle hole along the rotation axis while rotating the raw material block before the cutting step.

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