JP3604455B2 - Single-slot slot sizing device and manufacturing method of the slot - Google Patents

Description

【００３８】
【発明の効果】
以上、実施例で詳細に説明したように、本発明にかかる一溝スロット用サイジング装置および同スロットの製造方法によれば、生産速度を上げても、寸法精度がよく、かつ、表面も滑らかな一溝スロットが得られる。
【図面の簡単な説明】
【図１】本発明にかかるサイジング装置および製造方法が適用される一溝スロットの一例を示す断面図である。
【図２】本発明にかかる製造方法の一実施例を示す工程説明図である。
【図３】図３に示した押出機の吐出ダイスの孔部形状を示す説明図である。
【図４】本発明にかかるサイジング装置の一実施例を示す断面図断面図である。
【図５】図４に示したサイジング装置のサイジングダイの正面図である。
【図６】図４に示したサイジング装置のサイジングダイの側面図である。
【図７】図６に示したサイジングダイの空隙寸法を示す説明図である。
【図８】図５に示したサイジングダイの一方の型の一端側の斜視図である。
【図９】図５に示したサイジングダイの他方の型の一端側の斜視図である。
【図１０】図８，９に示した型の組み合わせ状態の断面図である。
【図１１】図５に示したサイジングダイの他方の型の他端側の斜視図である。
【図１２】本発明の製造方法で得られた一溝スロットの断面説明図である。
【図１３ 】本発明のサイジング装置の給水ジャケット内の水圧を制御する注水制御装置の一例を示す説明図である。
【符号の説明】
Ａ 一溝スロット（成形品）
Ａ_１ 本体
Ａ_２ テンションメンバー
Ａ_３ 溝部
１０ サイジングダイ
１０ａ 第１の型
１０ｂ 第２の型
１０ｆ，１０ｇ 給水孔
１０ｉ 排水孔
１２ 給水ジャケット
１４ 減圧チャンバー[0001]
[Industrial applications]
The present invention relates to a single-slot slot sizing apparatus and a method of manufacturing the same slot, and more particularly, to a sizing apparatus and a single-slot capable of high-speed manufacturing while maintaining high dimensional accuracy and surface roughness of a slot groove. The present invention relates to a method for manufacturing a slot.
[0002]
[Prior art]
Among the extruded products, for example, extruded products of irregular cross-sections having inwardly indented grooves, such as slots and window frames used in ultra-high-density optical fiber cables, the inner dimensions of the concave grooves It is required that the accuracy be high and the surface be smooth.
[0003]
In particular, such a demand has been further increased in a slot which is a component of an ultra-high-density optical fiber cable used in an optical highway concept which has recently been spotlighted on newspapers and the like. In other words, in this type of optical fiber cable, in order to further increase the density, the density of the core of the optical fiber tape accommodated in the groove of the slot is also increased, and the buffer layer for protecting the optical fiber is extremely increased. It is made thinner to increase the number of core wires to be stored.
[0004]
As a result, if the inner circumference of the groove has a dimensional change or irregularities on the surface, micro-bending loss is more likely to occur than in the conventional case, and the dimensional accuracy and surface roughness on the groove side are further improved. Is required.
By the way, this type of slot has been conventionally manufactured by the following manufacturing process.
{Circle around (1)} A molten thermoplastic resin is extruded on the outer periphery of the tension member in a state similar to a modified cross-section having a predetermined cross-sectional shape, for example, a circular groove-shaped concave groove portion.
{Circle around (2)} A sizing die (a mold having a void having a predetermined cross-sectional shape, a device for shaping while cooling one groove slot) is formed while cooling the thermoplastic resin.
{Circle around (3)} The obtained one groove slot is wound up on a bobbin.
[0005]
When twisting is desired to be applied to the groove of the slot, the following processing steps are carried out in a state where the above steps are continued or separated.
{Circle around (4)} The obtained one-groove slot is heated to a temperature higher than the softening point and lower than the melting point.
(5) Cool while adding twist. In this case, re-sincing is also performed.
(6) Take up on a bobbin.
[0006]
As a sizing method in such a manufacturing process, a method of guiding a slot to a two-segment sizing die in which only the tip end is outside the water tank, cooling while shaping (Japanese Patent Laid-Open No. 5-261844), A method of leading to a sizing die that can be divided into two and stored in a cooling jacket has been proposed.
However, each of such sizing methods has a technical problem described below.
[0007]
[Problems to be solved by the invention]
That is, in the former method, although there is relatively no problem in manufacturing at a low speed, when the production speed is increased, there is a problem that cooling in the groove becomes insufficient and the dimensional accuracy of the groove deteriorates. Also, in the latter method, the dimensional accuracy is better than the former method, and in order to increase the production speed while securing high dimensional accuracy, it is good to increase the length of the sizing die and the jacket. The pullout resistance of the slot becomes very large, and the slot may be broken.
[0008]
Furthermore, in the latter method, it is conceivable to seal the both ends of the sizing die, pressurize the cooling water supplied into the jacket, inject the cooling water from the joint of the sizing die, and directly cool the slot. In particular, in the case of a horizontal drawing structure, etc., there is a problem that the cooling water flows backward, and when the cooling water flows backward and stays near the entrance of the sizing die, the boiling water boils and an avatar is generated on the surface of the single groove slot. is there.
[0009]
The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a single-groove slot having a high dimensional accuracy and a smooth surface even when the production speed is increased. An object of the present invention is to provide a sizing device obtained and a method for manufacturing a single-groove slot using the sizing device.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a sizing device for a one-groove slot that includes a sizing die, a water supply jacket filled with cooling water, and a decompression chamber, and carries an optical fiber, wherein the sizing die is A water supply hole for supplying cooling water to a contact surface with the one groove slot is provided on an inlet side arranged in the water supply jacket, and a drainage for discharging cooling water to an intermediate portion arranged in the decompression chamber. It is characterized by having holes.
The one-slot slot has a main body having a substantially circular cross-section, and a concave groove having one end opened on the outer periphery of the main body. The sanding die has a first mold that contacts the outer periphery of the main body, and A split mold having a second mold that is in contact with an inner periphery, wherein the water supply hole is provided to the first and second molds so as to supply cooling water to an outer periphery of the main body and an inner periphery of the groove. In addition, the drain hole can be provided in the second mold so as to discharge the cooling water from the inner periphery of the groove.
The water supply jacket is connected to a water injection control device having a water supply fluctuation alleviating tank, a flow rate sensor, and a metering pump, and can feedback-control the metering pump based on a detection value of the flow rate sensor.
Further, as another invention, a one-groove slot having a substantially circular cross-section main body and a groove portion for storing an optical fiber whose one end is opened on the outer periphery of the main body is extruded and then cooled and shaped by a saijink device. In the manufacturing method, the sizing apparatus includes a sizing die, a water supply jacket filled with cooling water, and a decompression chamber, and on the inlet side arranged in the water supply jacket, the one-slot slot and the sizing die. The cooling water is supplied to the contact surface of the pressure reducing chamber, and the cooling water is discharged at an intermediate portion disposed in the decompression chamber.
In the above manufacturing method, the cooling water is supplied to an outer periphery of the main body and an inner periphery of the groove at an inlet side of the sizing die disposed in the water supply jacket. This can be performed from the inner periphery of the groove at an intermediate portion of the sizing die arranged in the chamber.
[0011]
[Action]
According to the single-slot slot sizing device and the method of manufacturing the same slot, first, cooling water is supplied to the contact surface between the single-slot slot and the sizing die on the inlet side arranged in the water supply jacket. A water film is formed between the one-slot slot and the surface that comes into contact with the sizing die. With this water film, the one-slot slot is directly cooled by cooling water, and the one-slot slot is cooled to a temperature below the heat deformation temperature in a short time. can do.
In addition, since this water film not only cools the single-groove slot but also functions as a lubricant between the sizing die and the single-groove slot, the pull-out resistance of the single-groove slot is greatly reduced. Can increase the production speed.
On the other hand, since the cooling water is filled in the water supply jacket, the supply of the cooling water between the sizing die and the one-groove slot can be reliably and largely performed by the water pressure. In this case, if a water injection control device that performs feedback control of the metering pump based on the detection value of the flow rate sensor is used, a stable one-groove slot can be manufactured.
Further, since the cooling water is discharged from an intermediate portion of the sizing die arranged in the decompression chamber, the flow direction of the cooling water becomes constant due to the forced drainage due to the decompression, and no backflow occurs.
At this time, when the cooling water is discharged, the one-slot is sucked to the sizing die by the depressurizing action, so that the dimensional accuracy and the surface accuracy of the one-slot are improved.
[0012]
【Example】
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 to 12 show one embodiment of a sizing apparatus for a single groove slot and a method of manufacturing the same slot according to the present invention. FIG. 1 shows a cross-sectional shape of a slot A to be manufactured.
[0013]
Slot A shown in the figure includes a substantially main body A ₁ of the thermoplastic resin having a circular cross section, three tension members A ₂ of which are embedded in the body A _1, so as to direct the inner body A ₁ be composed of Ochii設been concave groove a ₃ Metropolitan Te, groove a ₃ is formed on the entire length in the longitudinal direction of the body a _1. The numerical values shown in FIG. 1 are the design dimensions of the slot A to be obtained.
[0014]
FIG. 2 shows an example of a method for manufacturing the slot A. In the manufacturing method shown in the figure, as a tension member A _2, aromatic polyamide fiber: the (DuPont trade name Kevlar 49 1140de), also as a body A ₁ resin for forming the slots A, polybutylene terephthalate (Teijin (Trade name: C-7000N).
[0015]
The three tension members A ₂ are wound around a bobbin 2 supported by a creel stand 1, and are fed out of the bobbin 2 by applying a 450 g / book tension by a dancer roller 3, and passed through a preheating device 4 through an extruder. 5 crosshead dies. The resin extrusion temperature of the extruder 5 was set to 245 ° C. The discharge die mounted on the extruder 5 had a sectional shape as shown in FIG.
[0016]
That is, the hole shape of the discharge die, in consideration of dimensional shrinkage during the thermoplastic resin extruded from the extruder 5 is solidified, the width of a portion corresponding to the groove A ₃ and the length and the design dimensions (Figure 1 larger than the reference), and a shape notched the outer periphery of the portion to be the thickest of the body a _1. Such a resin from a discharge die to the outer periphery of the tension members A ₂ extrusion coated with the molten state, was introduced intermediate product extruded laterally from the extruder 5 into the sizing device 6.
[0017]
At this time, the take-up speed of the molded product is 8 m / min, the supply amount of the cooling water to the sizing device 6 is 900 ml / min, and the water pressure is 0.2 kg / cm ^2. Controlled at 30. The pressure in the decompression chamber described later was set to 40 mmHg. FIGS. 4 to 11 show details of the saijink device 6 used at this time. FIG. 4 is an overall view of the sizing device 6. The sizing device 6 includes a sizing die 10, a water supply jacket 12 filled with cooling water, and a decompression chamber 14.
[0018]
Sizing die 10 is arranged so as to penetrate the center of the water supply jacket 12 and vacuum chamber 14, as shown in detail in FIGS. 5 to 11, in contact with the outer periphery of the body A ₁ of the slot A (molded article) a first mold 10a which, combined with the type 10a, a split mold comprising a second mold 10b in contact with the inner periphery of the groove portion a ₃ of the slot a (molded article), formed in an elongated cylindrical shape Have been.
[0019]
The first mold 10a is formed in a shape in which a part of a hollow ring-shaped member is cut away as shown in FIG. 8, and the second mold 10b is formed as shown in FIG. The first mold 10a has an arc-shaped portion fitted into the notch portion, and a projection projecting upward from the arc-shaped portion, and is formed in a substantially convex shape.
FIG. 7 shows the dimensions and shape of the space formed between the first and second molds 10a and 10b when the first and second molds 10a and 10b are combined, that is, the space into which the slot A is inserted. I have. Further, the sizing die 10 is provided with three flange portions 10c to 10e at predetermined intervals along the longitudinal direction.
[0020]
As shown in FIG. 4, the flange portion 10c is in contact with a partition wall 14a defining the decompression chamber 14 with an O-ring interposed therebetween, and seals a liquid-tight seal between the water supply jacket 12 and the decompression chamber 14. . Further, the remaining two flange portions 10 d and 10 e abut on a support 16 provided in the decompression chamber 14 and are used for positioning the sizing die 10.
[0021]
Further, the sizing die 10, the inlet side disposed water jacket 12, and the outer periphery of the body A ₁ of the slot A from the outer circumference, the groove A ₃ of the inner and the water supply hole 10f for supplying cooling water, 10 g (The locations where the water supply holes 10f and 10g are provided are indicated by A and A 'in FIG. 5). As shown in FIG. 8, the water supply hole 10f provided in the first mold 10a radially penetrates the mold 10a so as to be directed toward the center.
[0022]
Water holes 10g provided in the second mold 10b, as shown in FIG. 9, to form a angular groove 10h, communicating in correspondence with the bottom and both ends of the rectangular groove 10h and the concave groove A ₃ As shown in FIG. The center water supply hole 10g is formed in a substantially cross shape so as to open at the upper end and both side ends of the square groove 10h. Furthermore, the sizing die 10, an intermediate portion disposed inside the vacuum chamber 14, the drainage holes 10i which only discharging cooling water from the inner periphery of the groove A ₃ is a predetermined interval along the longitudinal direction of the sizing die 10 Are provided.
[0023]
In FIG. 5, portions indicated by B _{1 to} B ₄ ′ are portions provided with the drain holes 10i, and the drain holes 10i form square grooves 10j as shown in FIG. the upper end of the angular groove 10j corresponding to the bottom portion of the angular groove 10j and the concave groove a _3, is formed in a substantially cross shape which respectively open to both side ends of the angular groove 10j corresponding to both sides of the concave groove a ₃ .
[0024]
On the other hand, the water supply jacket 12 is composed of a cylindrical portion 12a fixed to the partition wall 14a of the decompression chamber 14 and having both ends opened, and a lid portion 12c provided with an insertion hole 12b of the sizing die 10 at the center. An O-ring is interposed between 12b and the sizing die 10, and an O-ring is also interposed between the cylindrical portion 12a and the partition wall 14a to be sealed in a liquid-tight manner.
[0025]
The cylindrical portion 12a is provided with a cooling water inlet 12e. The decompression chamber 14 has a partition wall 14a that separates a hollow sealed space, an outlet packing 14b provided in the partition wall 14a, and a holding plate 14c. The outlet packing 14b has a cross-sectional shape corresponding to the shaped and cooled slot A, and is in close contact with the outer periphery and the inner periphery of the slot A to maintain the airtightness in the decompression chamber 14; Is fixed to the partition wall 14a by a holding plate 14c provided with a through hole.
[0026]
An exhaust and drain hole 14d is formed through the partition wall 14a, and a pressure reducing tank 20 is connected to the hole 14d via an opening / closing valve 18 as shown in FIG. The vacuum tank 20 is connected to a vacuum pump 22 that performs exhaust and drainage. The member denoted by reference numeral 21 in FIG. 4 is a shower nozzle that injects cooling water to the outer periphery of the sizing die 10 to cool it.
[0027]
A water supply control device 30 shown in FIG. 13 is connected to the water supply port 12 e of the water supply jacket 12. The water injection control device 30 adjusts the water pressure or the amount of water in the water supply jacket 12.
The water supply control device 30 shown in FIG. 3 includes a water supply fluctuation mitigation tank 30a connected to a water supply port 12e opened in the water supply jacket 12, a flow sensor 30a connected to the inlet side of the mitigation tank 30a, and a flow sensor 30b. It has a pressure regulating valve 30c, a flow indicator 30d, a pressure gauge 30e, a pressure reducing valve 30f, a metering pump 30g, a water supply tank 30h, a pressure gauge 30i, a pressure reducing valve 30j, and a pressure gauge 30k installed on the upstream side.
[0028]
A water supply source is installed at one end of the pressure gauge 30k, and a flow rate display 30l is connected to the flow rate sensor 30b. The water supply jacket 12 is provided with a water pressure sensor 30m for detecting the pressure in the jacket 12, and a water pressure indicator 30n is connected to the water pressure sensor 30m. An overflow passage 30o is provided in the water supply tank 30h, and a supply path 30q for supplying cooling water to the nozzle 21 installed in the decompression chamber 14 is provided upstream of the water supply tank 30h.
[0029]
In the water injection control device 30 configured as described above, the water pressure fluctuation on the upstream side is insulated by the water supply tank 30h, and the cooling water supplied to the water inlet 12e by the pressure reducing valve 30f installed on the downstream side of the water supply tank 30h. The pressure is set, the flow rate of the cooling water supplied by the flow rate sensor 30b is detected, and the drive of the metering pump 30g is feedback-controlled based on the detected value. When the water injection control device 30 having such a configuration and control is installed, the water pressure fluctuation of the cooling water becomes extremely large, for example, ² to 4 kg / cm ² when tap water is directly supplied. However, such a problem disappears.
[0030]
That is, the supply water pressure is low, the pressure of the cooling jacket 12 is lowered, the amount of water is insufficient, becomes insufficient cooling, smoothness of groove A ₃ is lost, the supply water pressure is high, the inlet of the cooling water Sanjingudai 10 And the shape of the slot A was greatly disturbed, and in some cases, reached the nozzle of the extruder 5. Therefore, in the present embodiment, the water injection control device 30 as described above was installed, and an experiment was performed to determine how much the fluctuation of the water supply pressure to the water supply jacket 12 is allowed. These experimental results confirmed that if the fluctuation of the water supply pressure was adjusted within ± 2.5%, a single-groove slot A with stable quality could be produced. In the water injection control device 30, the fluctuation of the water supply pressure can be suppressed within this range. In the water injection control device 30, the pressure regulating valve 30c may be feedback-controlled based on the detection signal of the water pressure sensor 30m.
[0031]
When the intermediate molded product is introduced into the saijink apparatus 10 configured as described above, the outer periphery of the main body A1 of the _one- groove slot A (molded product) and the groove portion A on the inlet side arranged in the water supply jacket 12. _Since the cooling water is supplied to the inner periphery of the sizing die 10 through the water supply holes 10f and 10g, the inner peripheral surfaces of the first die 10a and the second die 10 of the sizing die 10 and one groove slot A (molded product) ), A water film is formed between the entire outer peripheral surface and the outer periphery of the one-groove slot A (molded product) and the inner periphery of the groove portion are directly cooled by the cooling water. Molded article) can be cooled to below the heat distortion temperature in a short time.
[0032]
This water film not only cools the single groove slot A (molded product) but also functions as a lubricant between the sizing die 10 and the slot A (molded product). Product) greatly reduces pull-out resistance, thereby increasing the production speed.
On the other hand, since the cooling water is filled in the water supply jacket 12, the supply of the cooling water between the sizing die 10 and the one-slot slot A (molded product) can be performed reliably and in a large amount by the water pressure. You.
[0033]
The discharge of cooling water, the outlet being disposed within the vacuum chamber 14, from the outer periphery and the inner periphery, and in the middle portion, so performed as only discharging cooling water from the inner periphery of the groove A _3, by vacuum Due to the forced drainage, the flow direction of the cooling water is always from the water supply jacket 12 to the decompression chamber 14, and no backflow occurs.
At this time, when only the discharging cooling water from the inner periphery of the groove A _3, since the groove A ₃ inner circumference is sucked into the sizing die 10 by the action of vacuum, thus improving the groove A ₃ inner circumference of dimensional accuracy and surface accuracy.
[0034]
The single-groove slot A shaped and cooled as described above was taken up by the take-up machine 24, and then wound up on a bobbin by winding up (not shown). FIG. 12 shows a cross-sectional shape of the one-slot slot A obtained in the above manufacturing process. Table 1 below shows manufacturing conditions and dimensions of each part at that time.
The dimensions of the obtained single groove slot A were 3.9 mm in the groove width, 3.9 mm in the groove width, 4.1 mm outside the groove width, and 4.6 mm in the groove depth, which almost satisfied the design dimensions. Was. Observation of the cross section of the single-groove slot A with an optical microscope revealed that the surface layer of the slot A was very transparent, the inner layer was slightly cloudy, and a double structure was observed. This water supply hole 10f of the sizing die 10, for cooling water entering from the 10 g, the surface portion of the resin forming the body A ₁ of the slot A is rapidly cooled, be because that is a non-crystalline state .
[0035]
Then, the bobbin around which the single-groove linear slot A obtained as described above is wound is attached to a rotary feeder, and the single-groove linear slot A is rotated while being twisted (pitch: 500 mm) while being rewound while being twisted. The mixture was supplied to a heat treatment furnace, slot A was heated to about 160 ° C., and after cooling, it was wound up on a bobbin via a take-off machine. The groove shape of the slot after the twist was applied was not changed at all from that before the twist was applied.
Comparative Examples 1-3
As compared with the embodiment, the on-off valve 18 provided in the pipe connecting the decompression chamber 14 and the decompression tank 20 is closed, and the drainage and the exhaust in the decompression chamber 14 are not performed at all. To produce a single groove straight slot. At this time, when the take-up speed was 3.0 m / min and the amount of water supplied to the water supply jacket 12 was 100 ml / min (Comparative Example 1), a product having good dimensional accuracy was obtained under such conditions. Was.
[0036]
Also, if the take-up speed is increased to 5 m / min, the amount of water supplied to the water supply jacket 12 will be insufficient if the amount of water supplied to the water supply jacket 12 is 100 ml / min, and the dimensional accuracy of the groove will be considerably deteriorated. Fine irregularities occurred (Comparative Example 2). When the water supply amount was increased to 200 ml / min in order to compensate for the insufficient cooling in Comparative Example 2, the cooling water flowed backward from the sizing die 10 to the crosshead die side, the cooling point fluctuated, the shape deteriorated, and the slot decreased. A small patch-like defect was generated due to boiling of the cooling water retained on the surface of the groove. In some cases, cooling water was applied to the crosshead die, causing a problem that the discharge amount fluctuated.
[0037]
[Table 1]

[0038]
【The invention's effect】
As described in detail in the above embodiments, according to the sizing apparatus for a single groove slot and the method of manufacturing the same slot according to the present invention, even if the production speed is increased, the dimensional accuracy is good, and the surface is smooth. A single groove slot is obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a single-groove slot to which a sizing apparatus and a manufacturing method according to the present invention are applied.
FIG. 2 is a process explanatory view showing one embodiment of the manufacturing method according to the present invention.
FIG. 3 is an explanatory diagram showing a hole shape of a discharge die of the extruder shown in FIG.
FIG. 4 is a sectional view showing an embodiment of a sizing apparatus according to the present invention.
5 is a front view of a sizing die of the sizing device shown in FIG.
6 is a side view of a sizing die of the sizing device shown in FIG.
FIG. 7 is an explanatory view showing a gap size of the sizing die shown in FIG. 6;
FIG. 8 is a perspective view of one end of one mold of the sizing die shown in FIG.
FIG. 9 is a perspective view of one end of the other die of the sizing die shown in FIG. 5;
FIG. 10 is a sectional view of a combination state of the molds shown in FIGS.
11 is a perspective view of the other side of the other die of the sizing die shown in FIG.
FIG. 12 is an explanatory cross-sectional view of a single groove slot obtained by the manufacturing method of the present invention.
FIG. 13 is an explanatory diagram showing an example of a water injection control device for controlling a water pressure in a water supply jacket of the sizing device of the present invention.
[Explanation of symbols]
A Single groove slot (molded product)
A ₁ Body A ₂ Tension member A ₃ Groove 10 Sizing die 10a First mold 10b Second mold 10f, 10g Water supply hole 10i Drain hole 12 Water supply jacket 14 Decompression chamber

Claims (5)

A sizing die, a water supply jacket filled with cooling water, and a decompression chamber, a sizing device for a single-groove slot carrying an optical fiber,
The sizing die is provided with a water supply hole for supplying cooling water to a contact surface with the one-groove slot on an inlet side arranged in the water supply jacket,
A sizing device for a single-groove slot, wherein a drain hole for discharging cooling water is provided in an intermediate portion disposed in the decompression chamber. The one-groove slot has a main body having a substantially circular cross-section, and a concave groove having one end opened on the outer periphery of the main body,
The sanding die is a split mold having a first mold that contacts an outer periphery of the main body and a second mold that contacts an inner periphery of the groove.
The water supply holes are provided in the first and second molds so as to supply cooling water to an outer periphery of the main body and an inner periphery of the groove,
The sizing device for a single groove slot according to claim 1, wherein the drain hole is provided in the second mold so as to discharge cooling water from an inner periphery of the groove. The water supply jacket is connected to a water supply control device having a water supply fluctuation alleviating tank, a flow rate sensor, and a metering pump, and performs feedback control of the metering pump based on a detection value of the flow rate sensor. Item 1. A sanding device for a single groove slot according to item 1 or 2. A method of manufacturing a one-groove slot, in which a single-groove slot having a main body having a substantially circular cross-section and a groove portion for storing an optical fiber whose one end is opened on the outer periphery of the main body is extruded and then cooled and shaped by a saijink device,
The sizing device includes a sizing die, a water supply jacket filled with cooling water, and a decompression chamber.
Supplying cooling water to a contact surface between the one-slot and the sizing die on an inlet side arranged in the water supply jacket;
A method for manufacturing a single-groove slot, wherein the cooling water is discharged at an intermediate portion disposed in the decompression chamber. The cooling water is supplied to an outer periphery of the main body and an inner periphery of the groove at an inlet side of the sizing die arranged in the water supply jacket,
The method according to claim 4, wherein the cooling water is discharged from an inner periphery of the groove at an intermediate portion of the sizing die disposed in the decompression chamber.

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