JP5088441B1 - Tubular body manufacturing apparatus and tubular body manufacturing method - Google Patents

Abstract

A tubular body with little variation in inner diameter can be produced for a long time.
A filling step of filling a gap into a gap between a cooling member having a cylindrical surface or a conical surface and a supporting member that supports the cooling member and cools the cooling member; An extrusion process for extruding the tube downward, and the cylindrical surface or the conical surface of the cooling member in which the gap is filled with liquid while taking up the tubular resin material extruded in the extrusion process. And a cooling step of cooling the resin material in contact with the surface.
[Selection] Figure 2

Description

  The present invention relates to a tubular body manufacturing apparatus and a tubular body manufacturing method.

  In Patent Document 1, an extrusion process of extruding a molten fluororesin material into a tube shape with a mold, and continuously taking out the tubular fluororesin material extruded from the mold at a constant take-off speed, A fluororesin tube is manufactured by a cooling process in which the inner peripheral surface of the tubular fluororesin material is brought into contact with the outer peripheral surface of a cylindrical cooling member in the vicinity and the tubular fluororesin material is cooled to a temperature of 170 ° C. or lower. A manufacturing method is disclosed.

JP 2010-125634 A

  An object of the present invention is to produce a tubular body with little variation in inner diameter for a long time.

The invention of claim 1 includes an inner peripheral surface of an insertion hole formed in a cooling member having a cylindrical surface or a conical surface, an outer peripheral surface of a support member that cools the cooling member in a state of being inserted into the insertion hole , A filling step of filling the gap with a liquid, an extrusion step of extruding the molten resin material downward in a tubular shape by a mold, and a liquid portion in the gap while taking up the tubular resin material extruded by the extrusion step at the take-up portion A cooling step in which the cylindrical surface or the conical surface of the cooling member filled with is brought into contact with the inner peripheral surface of the resin material to cool the resin material.

  Invention of Claim 2 is the manufacturing method of the tubular body of Claim 1 with which the said filling process fills the liquid which is water or a liquid with a boiling point of 100 degreeC or more as said liquid.

  In the invention according to claim 3, in the cooling step, the conical surface of the cooling member having a conical surface reduced in diameter downward is brought into contact with the inner peripheral surface of the resin material to cool the resin material, Furthermore, it is a manufacturing method of the tubular body of Claim 1 or 2 including the change process which moves the said cooling member to an up-down direction, and changes the contact position with respect to the internal peripheral surface of the said resin material of the said conical surface.

  The invention of claim 4 is the state in which the changing step is such that the tubular resin material is connected from the mold to the take-up portion, and the conical surface of the cooling member is in contact with the inner peripheral surface of the resin material. It is a manufacturing method of the tubular body of Claim 3 which moves the said cooling member and changes the contact position with respect to the internal peripheral surface of the said resin material of the said conical surface.

The invention of claim 5 has an extruding part for extruding a molten resin material into a tubular shape by a mold, a take-up part for taking up the tubular resin material extruded from the mold by the extruding part, and a cylindrical surface or a conical surface. And a cooling member that cools the resin material by bringing the cylindrical surface or the conical surface into contact with the inner peripheral surface of the resin material taken up by the take-up portion, and a state inserted into the insertion hole formed in the cooling member A support member that supports the cooling member and cools the cooling member , and a replenishment unit that replenishes liquid in a gap between the inner peripheral surface of the insertion hole in the cooling member and the outer peripheral surface of the support member. An apparatus for manufacturing a tubular body.

  A sixth aspect of the present invention is the tubular body manufacturing apparatus according to the fifth aspect, wherein the replenishing portion replenishes the liquid that is water or a liquid having a boiling point of 100 ° C. or higher.

  According to a seventh aspect of the present invention, the cooling member has a conical surface that is reduced in diameter downward, and the conical surface is brought into contact with an inner peripheral surface of the resin material that is taken up by the take-up portion. The tubular body according to claim 5 or 6, further comprising a moving mechanism that cools and further moves the cooling member in a vertical direction to change a contact position of the conical surface of the cooling member with respect to the inner peripheral surface of the resin material. It is a manufacturing apparatus.

  The invention according to claim 8 is the operation of the moving mechanism in a state in which the tubular resin material is connected from the mold to the take-up portion and the conical surface of the cooling member is in contact with the inner peripheral surface of the resin material. It is a manufacturing apparatus of the tubular body of Claim 7 provided with a possible operation part.

  According to the manufacturing method of claim 1 of the present invention, it is possible to manufacture a tubular body having a small variation in inner diameter for a long time as compared with the case where there is no filling step in the manufacturing method.

  According to the manufacturing method of claim 2 of the present invention, it is possible to manufacture a tubular body having a small variation in inner diameter for a long time as compared with the case of filling a liquid having a boiling point lower than that of water.

  According to the manufacturing method of Claim 3 of this invention, the internal diameter of the tubular body manufactured can be changed, without replacing | exchanging a cooling member.

  According to the manufacturing method of claim 4 of the present invention, the inner diameter of the tubular body can be changed while the tubular body is manufactured.

  According to the configuration of the fifth aspect of the present invention, it is possible to manufacture a tubular body having a small variation in inner diameter for a long time as compared with the case where the replenishment portion in the present configuration is not provided.

  According to the configuration of the sixth aspect of the present invention, it is possible to manufacture a tubular body having a small variation in inner diameter for a long time as compared with the case of replenishing a liquid having a boiling point lower than that of water.

  According to the structure of Claim 7 of this invention, the internal diameter of the tubular body manufactured can be changed, without replacing | exchanging a cooling member.

  According to the configuration of the eighth aspect of the present invention, the inner diameter of the tubular body can be changed while the tubular body is manufactured.

It is the schematic (sectional drawing) which shows the structure of a melt extrusion molding apparatus. It is the schematic (sectional drawing) which expands and shows a part of structure of a melt extrusion molding apparatus. It is the schematic (sectional drawing) which shows the structure of the front-end | tip part of a supporting member, and a cooling member. It is the schematic (sectional drawing) which shows the state before and behind moving the cooling member up and down. The temperature change of the cooling member was shown when the gap between the inner peripheral surface of the cooling member and the outer peripheral surface of the support member was filled with a 20% aqueous solution of ethylene glycol and when the gap was not filled with liquid. It is a graph. When the gap between the inner peripheral surface of the cooling member and the outer peripheral surface of the support member is filled with 20% aqueous solution of ethylene glycol, when the gap is filled with water, and when the gap is not filled with liquid Is a graph showing the change over time of the inner diameter of the manufactured resin material tube. It is the graph which showed the relationship between the position of the cooling member when moving a cooling member with a moving mechanism, and the internal diameter of the resin material tube manufactured. It is a figure which shows the moving mechanism which concerns on a modification.

  Below, an example of an embodiment concerning the present invention is described based on a drawing.

[Melt Extruder 100]
First, the structure of the melt extrusion molding apparatus 100 as an example of a tubular body manufacturing apparatus will be described. FIG. 1 is a schematic diagram (cross-sectional view) showing a configuration of a melt extrusion molding apparatus 100. FIG. 2 is a schematic diagram (cross-sectional view) showing a partially enlarged configuration of the melt extrusion molding apparatus 100. Note that the drawings referred to below are used for explaining the present embodiment, and do not show the actual size ratio.

  As shown in FIG. 1, the melt extrusion molding apparatus 100 includes an extrusion unit 110 that extrudes a molten (dissolved) resin material F into a tubular shape by a mold 20, and is extruded downward from the mold 20 of the extrusion unit 110. The take-up machine 50 as an example of a take-up section for taking up the tubular resin material F, and cooling for cooling the molten resin material F by bringing the outer peripheral surface into contact with the inner peripheral surface of the resin material F taken up by the take-up machine 50 A member (sizing die) 30, a support member 70 that supports the cooling member 30, and a winder 60 that winds up the tubular resin material F taken up by the take-up machine 50 are provided.

  Further, as shown in FIG. 2, the melt extrusion molding apparatus 100 includes a moving mechanism 80 that moves the cooling member 30 in the vertical direction, and a replenishment unit 90 that replenishes the gap S between the cooling member 30 and the support member 70. And.

  The resin material used in the melt extrusion molding apparatus 100 is a resin material having heat shrinkability. In the present embodiment, for example, a fluororesin material is used. Examples of the fluororesin material include polytetrafluoroethylene resin (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA), fluorinated ethylene-propylene copolymer resin (FEP), and polyvinylidene fluoride resin. (PVDF), polyvinyl fluoride resin and the like. Among these, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA) is preferable.

(Extruded part 110)
As shown in FIG. 1, the extrusion unit 110 includes a uniaxial extruder 10 that prepares the resin material F in a molten state, and a die (die) 20 that is attached to the tip of the uniaxial extruder 10. Yes.

  The single screw extruder 10 includes a heating cylinder 12 that has a heater (not shown) and heats the resin material F, a hopper 11 that is provided in the heating cylinder 12 and serves as an input port into which the resin material F is charged, and a heating cylinder 12. And a screw 13 as a conveying member that is provided and conveys the resin material F to the mold 20.

  In the single screw extruder 10, the resin material F introduced into the heating cylinder 12 from the hopper 11 is heated by the heater of the heating cylinder 12 at a temperature equal to or higher than the melting point of the resin material F (usually 350 to 450 ° C.). Thus, while being melted, it is conveyed (supplied) to the mold 20 by the screw 13. In the single screw extruder 10, a resin material F (pellet) formed in a granular form is charged into the hopper 11.

  As shown in FIG. 2, the mold 20 has a flow path 22 through which the molten resin material F flowing from the heating cylinder 12 passes through the inside of the heating cylinder 12 of the single screw extruder 10, and a flow path 22. An annular (circular) outlet hole 23 for extruding the molten resin material F that has passed therethrough into a tubular shape is formed.

  In the mold 20, the molten resin material F flows into the flow path 22 from the tip of the heating cylinder 12 and passes through the flow path 22, and propulsive force (conveyance force) due to the rotation of the screw 13 of the single screw extruder 10. Thus, it is pushed out from the outlet hole 23 into a tubular shape.

(Support member)
As shown in FIG. 2, the support member 70 is formed in a columnar shape, and penetrates the mold 20 at the radial center (center) of the outlet hole 23 formed in an annular shape in the mold 20. The mold 20 is supported so as to be movable in the vertical direction so as to protrude above and below the mold 20.

  Inside the support member 70, a coolant channel 72 through which the coolant flows is provided. The refrigerant flow path 72 is connected to a cooler (not shown) and is formed along the axial direction of the support member 70. In the support member 70, the refrigerant cooled by a cooler (not shown) circulates through the refrigerant flow path 72, thereby cooling the cooling member 30. Note that the refrigerant flow path 72 meanders at the inner peripheral side portion of the cooling member 30 at the front end portion (lower end portion) of the support member 70, and the cooling efficiency for cooling the cooling member 30 is enhanced.

  The refrigerant flowing through the refrigerant flow path 72 is not particularly limited, and examples thereof include water, a water bath solution (brine) of ethylene glycol or propylene glycol, and the like. In this embodiment, water is used.

As shown in FIG. 3, a screw portion 74 is formed on the outer periphery of the tip portion of the support member 70. A nut 76 for supporting the cooling member 30 is screwed into the screw portion 74. The nut 76 may be provided integrally with the cooling member 30. Also,
In this embodiment, the liquid is replenished (filled) into the gap S between the cooling member 30 and the support member 70, but the gap between the screw portion 74 and the nut 76 is very small, so that the liquid leaks. There is no such thing. When there is a concern about leakage of the liquid, a sealing member that seals the gap between the screw portion 74 and the nut 76 may be provided.

(Cooling member)
As shown in FIG. 3, the cooling member 30 is formed in a truncated cone shape having a conical surface 34 whose diameter is reduced downward. An insertion hole 32 that penetrates in the vertical direction (axial direction) and into which the support member 70 is inserted is formed in the central portion in the radial direction of the cooling member 30.

  The cooling member 30 has a distal end portion (lower end portion) of the support member 70 inserted into the insertion hole 32, and a nut screwed into the screw portion 74 of the support member 70 below the cooling member 30 (the distal end side of the support member 70). The support member 70 is supported by 76.

  Further, the cooling member 30 can be inserted into and removed from the support member 70 by removing the nut 76 from the screw portion 74, and can be replaced with another cooling member 30 (for example, the cooling member 30 having a different outer diameter). Has been. That is, the cooling member 30 is fitted in a gap with respect to the distal end portion of the support member 70.

  Thus, since the cooling member 30 has a clearance fit that can be inserted into and removed from the support member 70, the inner peripheral surface of the cooling member 30 and the support member 70 in a state where the cooling member 30 is supported by the support member 70. A gap S is formed between the outer peripheral surface of the first and second outer peripheral surfaces.

  In the cooling member 30, the resin material F is cooled by bringing the conical surface 34 into contact with the inner peripheral surface of the resin material F which is pushed out in a tubular shape from the outlet hole 23 of the mold 20 and taken up by the take-up machine 50. It has become. The cooled resin material F is reduced in diameter and hardened. The inner diameter of the resin material F to be cured is determined by the outer diameter of the portion in contact with the conical surface 34.

  As shown in FIG. 1, the resin material taken up by the take-up machine 50 in the path of the resin material F from the cooling member 30 to the take-up machine 50 (specifically, below the cooling member 30). A tension applying roll 40 that applies tension to F is provided.

(Pickup machine)
As shown in FIG. 1, the take-up machine 50 includes a pair of endless belts 52 each wound around two rolls 54 arranged at intervals. The pair of endless belts 52 are arranged vertically so that the surfaces are in contact with each other. The endless belt 52 arranged on the upper side circulates in the direction of arrow B in FIG. 1, and the endless belt 52 arranged on the lower side circulates in the direction of arrow C in FIG.

  In the take-up machine 50, the resin material F cooled by the cooling member 30 is sandwiched between the portions where the pair of endless belts 52 are in contact (clamping portions), and the pair of endless belts 52 circulate so that the resin material F becomes a tension applying roll. In the state where the tension is applied by 40, it is taken up at a constant speed.

(Winding machine)
As shown in FIG. 1, the winder 60 includes a rotating body 62 that continuously winds the resin material F taken up by the take-up machine 50 at a predetermined speed. A known rotating body can be used as the rotating body, and is not particularly limited.

(Movement mechanism 80)
As shown in FIG. 2, the moving mechanism 80 includes a fixing member 82 fixed to the support member 70 above the mold 20, and a plurality of bolts 84 screwed into the fixing member 82. Yes.

  The fixing member 82 projects outward from the support member 70 in the radial direction. The fixing member 82 is formed with a screw portion 82A into which the bolt 84 is screwed. Each bolt 84 is screwed into the screw portion 82A of the fixing member 82 so that the head portion 84A is disposed above and the tip of the shaft portion 84B abuts against the upper surface of the mold 20.

  In the moving mechanism 80, the support member 70 and the cooling member 30 are moved by turning a plurality of bolts 84 to change the protruding amount protruding from the fixing member 82 to the upper surface of the mold 20. The movement of the support member 70 and the cooling member 30 is a state in which the tubular resin material F is connected from the mold 20 to the take-up machine 50 and the conical surface 34 of the cooling member 30 is in contact with the inner peripheral surface of the resin material F. Is also possible.

  That is, in this embodiment, the bolt 84 is in a state where the tubular resin material F is connected from the mold 20 to the take-up machine 50 and the conical surface 34 of the cooling member 30 is in contact with the inner peripheral surface of the resin material F. It functions as an example of an operation unit capable of operating the moving mechanism 80.

  As described above, the moving mechanism 80 moves the cooling member 30 in the vertical direction, so that the contact position of the conical surface 34 of the cooling member 30 with the inner peripheral surface of the resin material F is changed.

  In the above example, the moving mechanism 80 includes a plurality of adjustment bolts 84. However, the movement mechanism 80 includes a single adjustment bolt 84 and a guide that restricts the movement direction only in the vertical direction. May be.

(Replenisher 90)
For example, the replenishment unit 90 replenishes a gap S between the inner peripheral surface of the cooling member 30 and the outer peripheral surface of the support member 70 with a part of the refrigerant flowing through the refrigerant flow path 72 of the support member 70. ing. That is, as the refrigerant in the gap S decreases, the refrigerant is replenished.

  Specifically, the height of the liquid filled in the gap S is monitored by a commercially available sensor such as a liquid level sensor. When the output value (liquid level height) of the sensor becomes a predetermined value or less, the electromagnetic valve communicating with the refrigerant flow path 72 is opened and a part of the refrigerant flowing in the refrigerant flow path 72 is replenished to the gap S. When the output value of the sensor reaches a predetermined value, the solenoid valve is closed and the supply of the refrigerant to the gap S is stopped.

  The replenishing unit 90 is not limited to the configuration for replenishing the refrigerant flowing through the refrigerant flow path 72, and may be configured to replenish a liquid prepared separately from the refrigerant.

  As the liquid replenished by the replenishing unit 90, a liquid having a higher thermal conductivity than air is used. For example, water or a liquid having a boiling point of 100 ° C. or higher is used. The liquid having a boiling point of 100 ° C. or higher is a liquid at room temperature (25 ° C.), for example, a polymer such as alcohols, esters, polyhydric alcohols, polyethers, or a mixture thereof. Is used.

[Method for producing heat-shrinkable resin tube]
Next, the manufacturing method which manufactures the heat-shrinkable resin tube as an example of a tubular body using the above-mentioned melt extrusion molding apparatus 100 is demonstrated.

  In the present manufacturing method, first, as shown in FIG. 2, a part of the refrigerant flowing through the refrigerant flow path 72 of the support member 70 is separated from the inner peripheral surface of the cooling member 30 and the support member 70 using the replenishment unit 90. Is filled in the gap S between the outer peripheral surface (filling step).

  In the present embodiment, the refrigerant is replenished from the replenishing unit 90 as the refrigerant decreases in the gap S.

  Further, in the filling process, the replenishment unit 90 is not used, and the liquid is filled into the gap S between the inner peripheral surface of the cooling member 30 and the outer peripheral surface of the support member 70 by, for example, an operator's manual operation. It may be.

  As the liquid to be filled, a liquid having a higher thermal conductivity than air is used. For example, water or a liquid having a boiling point of 100 ° C. or higher is used. The liquid having a boiling point of 100 ° C. or higher is a liquid at room temperature (25 ° C.), for example, a polymer such as alcohols, esters, polyhydric alcohols, polyethers, or a mixture thereof. Is used.

  Next, the resin material F (pellet) is put into the heating cylinder 12 from the hopper 11 of the single screw extruder 10 (see FIG. 1), and the resin material F is fed by a plurality of heaters (not shown) of the heating cylinder 12. The resin material F is heated to a temperature equal to or higher than the melting point of the resin material F (usually 350 to 450 ° C.) to be in a molten state (heating process).

  Next, as shown in FIG. 1, the molten resin material F is passed through the flow path 22 of the mold 20 from the heating cylinder 12 by the propulsive force of the screw 13 inside the heating cylinder 12, and the mold Extruded into a tube from 20 outlet holes 23 (extrusion process).

  Next, the resin material F extruded in a tubular shape from the outlet hole 23 of the mold 20 is continuously taken out at a constant take-up speed by the take-up machine 50, and the cooling member 30 is placed on the inner peripheral surface of the resin material F. The resin material F is cooled and hardened by bringing the conical surface 34 into contact (cooling step).

  Next, the cooled / cured resin material is continuously wound by the winder 60. As described above, in this embodiment, the resin material F extruded in a tubular shape from the outlet hole 23 of the mold 20 is cooled and hardened by the cooling member 30 while being continuously taken at a constant take-off speed, so that the heat shrinkability is improved. The resin tube which has is manufactured.

  Here, when changing (adjusting) the inner diameter of the resin tube to be manufactured, the cooling member 30 is moved up and down by the moving mechanism 80 (see FIG. 2), and the resin on the conical surface 34 of the cooling member 30 is moved. The contact position with respect to the internal peripheral surface of the material F is changed (change process).

  4A shows the cooling member 30 before moving, and FIG. 4B shows the moving cooling member 30 after moving the cooling member 30 downward, and FIG. C) shows the cooled cooling member 30 after moving the cooling member 30 upward. 4A, 4B, and 4C, the solid line D indicates the contact position between the cooling member 30 and the resin material F. In addition, X1, X2, and X3 in FIGS. 4A, 4B, and 4C indicate the inner diameters of the resin tubes to be manufactured. X1, X2, and X3 have a relationship of X3 <X1 <X2.

  When it is desired to increase the inner diameter of the resin tube to be manufactured, the bolt 84 is loosened with respect to the screw portion 82A of the fixing member 82 (see FIG. 2), and the shaft portion 84B protruding from the fixing member 82 to the upper surface of the mold 20 is used. As shown in FIG. 4B, the cooling member 30 is moved downward by reducing the protrusion amount.

  When it is desired to reduce the inner diameter of the resin tube to be manufactured, the bolt 84 is fastened (screwed) to the screw portion 82A of the fixing member 82, and the shaft portion protruding from the fixing member 82 to the upper surface of the mold 20 By increasing the protrusion amount of 84B, the cooling member 30 is moved upward as shown in FIG.

  Thus, the contact position with respect to the conical surface 34 of the cooling member 30 of the resin material F is changed by moving the cooling member 30 to an up-down direction. Thereby, the inner diameter of the resin tube is finely adjusted. It should be noted that the take-up speed of the take-up machine 50 is constant before the cooling member 30 is moved (FIG. 4A) and after the movement (FIGS. 4B and 4C), and from the outlet hole 23 of the mold 20. The discharge angle is constant. Further, the thickness of the resin material F at the position in contact with the cooling member 30 also hardly changes before the movement of the cooling member 30 (FIG. 4A) and after the movement (FIGS. 4B and 4C). When the inner diameter of the manufactured resin tube is changed, the outer diameter of the manufactured resin tube is also changed.

  Specifically, in this change step, the tubular resin material F is connected from the mold 20 to the take-up machine 50, and the conical surface 34 of the cooling member 30 is in contact with the inner peripheral surface of the resin material F. The contact position with respect to the internal peripheral surface of the resin material F of the conical surface 34 is changed by moving the cooling member 30.

  And after the said change process, the resin tube which has heat-shrinkability is manufactured through a heating process, an extrusion process, a cooling process, etc. similarly to the above-mentioned.

  In this embodiment, when the cooling member 30 is removed from the support member 70 and can be replaced, and the inner diameter size of the resin tube to be changed exceeds the range of the inner diameter size that can be adjusted by one cooling member 30. Are replaced with cooling members 30 having different outer diameters.

[Operation of this embodiment]
Next, the operation of this embodiment will be described.

  As described above, in this embodiment, the cooling member 30 having the conical surface 34 whose diameter is reduced downward is moved up and down, so that the contact position of the conical surface 34 with the inner peripheral surface of the resin material F is changed. Be changed. Thereby, the internal diameter of the resin tube manufactured is changed, without replacing | exchanging the cooling member 30. FIG.

  In the present embodiment, in particular, the resin manufactured in a state where the resin material F is connected to the take-up machine 50 from the mold 20 and the conical surface 34 of the cooling member 30 is in contact with the inner peripheral surface of the resin material F. The inner diameter of the tube is changed.

  Therefore, in this embodiment, it becomes unnecessary to cut the tubular resin material F, and the changing operation is simplified. That is, in the case of a configuration (comparative example) in which the cooling member 30 is directly operated and changed, it is necessary to cut the tubular resin material F in order to expose the cooling member 30. Thus, since the cutting of the tubular resin material F is unnecessary, the contact position of the conical surface 34 with respect to the inner peripheral surface of the resin material F is changed while the resin tube is being manufactured (during the manufacturing of the resin tube). May be.

  In the present embodiment, since the cooling member 30 is efficiently cooled by the support member 70 by filling the gap S between the inner peripheral surface of the cooling member 30 and the outer peripheral surface of the support member 70, the cooling member The temperature fluctuation of 30 is small. Thereby, the heat shrinkage rate generated in the resin material F cooled by the cooling member 30 does not vary, and a resin tube with a small variation in inner diameter is manufactured for a long time.

[Effect confirmation test]
FIG. 5 shows a case where the gap S between the inner peripheral surface of the cooling member 30 and the outer peripheral surface of the support member 70 is filled with an ethylene glycol 20% aqueous solution, and a case where the gap S is not filled with liquid. 6 is a graph showing a temperature change of the cooling member 30.

  As shown in the graph of FIG. 5, when the gap S between the inner peripheral surface of the cooling member 30 and the outer peripheral surface of the support member 70 is filled with a 20% aqueous solution of ethylene glycol, the gap S is filled with liquid. It can be seen that the temperature rise of the cooling member 30 is small as compared with the case where it is not.

  FIG. 6 shows a case where the gap S between the inner peripheral surface of the cooling member 30 and the outer peripheral surface of the support member 70 is filled with an ethylene glycol 20% aqueous solution, a case where the gap S is filled with water, and the gap S. 5 is a graph showing a change with time of the inner diameter of the manufactured resin material tube when the liquid is not filled with liquid. The vertical axis represents the inner diameter (mm) of the resin tube, and the horizontal axis represents the production time of the resin tube (take time by the take-up machine 50).

  As shown in the graph of FIG. 6, when the gap 20 between the inner peripheral surface of the cooling member 30 and the outer peripheral surface of the support member 70 is filled with a 20% aqueous solution of ethylene glycol, the take-up time by the take-up machine 50 is increased. It can be seen that a resin tube with a small change in the inner diameter of the produced resin tube and a small variation in the inner diameter is produced until 60 minutes elapses.

  In addition, when the gap S is filled with water (no operation of the replenishing unit 90), the change in the inner diameter of the resin tube to be manufactured is small until the take-up time by the take-up machine 50 elapses 30 minutes. It can be seen that a resin tube with a small variation in the thickness is manufactured. The reason why the inner diameter of the resin tube changes when 30 minutes have passed after the gap S is filled with water is that the replenishment section 90 is not operated, and a part of the water in the gap S evaporates to This is because the amount has decreased. For this reason, if water is regularly replenished into the gap S by the replenishing unit 90, it is presumed that a resin tube with a small variation in inner diameter is produced even after 30 minutes have passed.

  As described above, in the case where the gap S is not filled with the liquid, the change in the inner diameter of the resin tube to be manufactured is large and the variation in the inner diameter is long until the take-up time by the take-up machine 50 is 30 minutes. It turns out that a resin tube with many is manufactured.

  FIG. 7 is a graph showing the relationship between the position (horizontal axis) of the cooling member 30 when the cooling member 30 is moved by the moving mechanism 80 and the inner diameter (vertical axis) of the manufactured resin material tube. The length shown on the horizontal axis is the length L shown in FIG. 2 and is the length from the fixing member 82 to the upper surface of the mold 20.

  As shown in the graph of FIG. 7, it can be seen that the position of the cooling member 30 and the inner diameter of the resin material tube to be manufactured are in a proportional (linear function) relationship. Therefore, it becomes easy to obtain the position of the cooling member 30 according to the desired tube inner diameter to be manufactured.

[Movement mechanism 180 according to modification]
FIG. 8 is a diagram illustrating a moving mechanism 180 according to a modification.

  The moving mechanism 180 includes a screw portion 39 formed on the inner peripheral surface of the cooling member 30 and a screw portion 79 formed on the outer peripheral surface of the support member 70 and screwed into the screw portion 39. .

  In this configuration, the cooling member 30 is moved in the vertical direction with respect to the support member 70 by rotating the cooling member 30. Thereby, the contact position with respect to the internal peripheral surface of the resin material F of the conical surface 34 of the cooling member 30 changes, and without replacing | exchanging the cooling member 30, the internal diameter of the resin tube manufactured is changed.

  Also in this configuration, the gap S between the screw portion 39 of the cooling member 30 and the screw portion 79 of the support member 70 may be filled with liquid. For example, the replenishment portion 90 described above is used to fill the support member 70. A part of the refrigerant flowing through the refrigerant flow path 72 may be replenished in the gap S between the screw part 39 of the cooling member 30 and the screw part 79 of the support member 70.

[Other variations]
The melt extrusion molding apparatus 100 described above includes the moving mechanism 80 (the moving mechanism 180), but may be configured not to include the moving mechanism 80 (the moving mechanism 180).

  Moreover, in the manufacturing method of the above-mentioned heat-shrinkable resin tube, although the change process was included, it is not necessary to perform a change process.

  In addition, the cooling member 30 described above has the conical surface 34 that is reduced in diameter toward the lower side. However, the cooling member 30 may have a cylindrical surface that has a constant outer diameter in the vertical direction.

  The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements can be made. For example, the modification examples described above may be appropriately combined.

20 Mold 30 Cooling member 34 Conical surface 50 Take-up machine (example of take-up part)
70 Support member 80 Moving mechanism 84 Bolt (an example of an operation unit)
90 replenishment unit 100 melt extrusion molding equipment (manufacturing equipment)
110 Extrusion part 180 Movement mechanism F Resin material S Crevice

Claims (8)

An inner peripheral surface of an insertion hole formed in a cooling member having a cylindrical surface or a conical surface, and an outer peripheral surface of a support member that supports the cooling member while being inserted into the insertion hole and cools the cooling member. A filling step of filling the gap with liquid;
An extrusion process for extruding the molten resin material downward in a tubular shape with a mold;
While taking up the tubular resin material extruded by the extrusion process at the take-up portion, the cylindrical surface or the conical surface of the cooling member filled with the liquid in the gap is brought into contact with the inner peripheral surface of the resin material. A cooling step for cooling the resin material;
The manufacturing method of the tubular body containing this.   The said filling process is a manufacturing method of the tubular body of Claim 1 filled with the thing which is water or a liquid with a boiling point of 100 degreeC or more as said liquid. The cooling step cools the resin material by bringing the conical surface of the cooling member having a conical surface reduced in diameter downwards into contact with the inner peripheral surface of the resin material,
Furthermore, the manufacturing method of the tubular body of Claim 1 or 2 including the change process which moves the said cooling member to an up-down direction, and changes the contact position with respect to the internal peripheral surface of the said resin material of the said conical surface.   The changing step includes moving the cooling member in a state where the tubular resin material is connected from the mold to the take-up portion and the conical surface of the cooling member is in contact with the inner peripheral surface of the resin material. The manufacturing method of the tubular body of Claim 3 which changes the contact position with respect to the internal peripheral surface of the said resin material of the said conical surface. An extrusion section for extruding the molten resin material into a tubular shape by a mold;
A take-up part for taking up the tubular resin material extruded from the mold at the extrusion part;
A cooling member having a cylindrical surface or a conical surface, and cooling the resin material by bringing the cylindrical surface or the conical surface into contact with an inner peripheral surface of the resin material taken up by the take-up portion;
A support member that supports the cooling member in a state of being inserted into an insertion hole formed in the cooling member, and cools the cooling member;
A replenisher for replenishing liquid in the gap between the inner peripheral surface of the insertion hole in the cooling member and the outer peripheral surface of the support member ;
A tubular body manufacturing apparatus comprising:   The said replenishing part is a manufacturing apparatus of the tubular body of Claim 5 which replenishes what is water or a liquid with a boiling point of 100 degreeC or more as said liquid. The cooling member has a conical surface whose diameter is reduced downward, and the resin material is cooled by bringing the conical surface into contact with an inner peripheral surface of the resin material taken up by the take-up part,
Furthermore, the manufacturing apparatus of the tubular body of Claim 5 or 6 provided with the moving mechanism which moves the said cooling member to an up-down direction, and changes the contact position with respect to the internal peripheral surface of the said resin material of the conical surface of the said cooling member. .   The tubular resin material is provided with an operation portion operable to operate the moving mechanism in a state where the tubular resin material is connected from the mold to the take-up portion, and a conical surface of the cooling member is in contact with an inner peripheral surface of the resin material. Item 8. The tubular body manufacturing apparatus according to Item 7.