JP4832251B2 - Manufacturing method of synthetic resin hose - Google Patents

Description

The present invention relates to a manufacturing method of a synthetic resin hose having a heat insulating property.

  As a heat insulating hose, conventionally, for example, as described in Patent Document 1, an outer peripheral surface of an inner tube made of a soft vinyl chloride resin is made of a foamed polyethylene resin via a partition wall made of the same material as the inner tube. A heat insulating layer is formed by spirally winding a belt-shaped heat insulating material, and the outer peripheral surface of the heat insulating layer is covered with a soft synthetic resin outer tube made of the same material as the inner tube. As is well known, the use of such a heat-insulating hose increases the material cost, making it difficult to supply inexpensive products, as well as inner and outer pipes made of soft vinyl chloride resin and foamed polyethylene. Since it is difficult to bond to the heat insulating material made of resin, the heat insulating material is pulled out from the cut end surface of the hose and the end portion is deformed. To prevent this, the cut end portion is wound with a thread. Keep There is a problem that becomes necessary processing of.

  On the other hand, it is known that the air layer has an appropriate heat insulating effect without using the above heat insulating material, and an air layer is provided between the inner tube and the outer tube made of the soft synthetic resin. If it does, heat insulation can be exhibited.

For example, as described in Patent Document 2, a hard synthetic resin reinforcing core wire is spirally wound around the outer peripheral surface of a soft synthetic resin inner tube at a constant pitch. Is coated with a soft synthetic resin outer tube made of the same material as the inner tube, and the inner peripheral surface of the soft synthetic resin outer tube in contact with the top of the reinforcing core wire is integrally fused to the reinforcing core wire. As a result, a synthetic resin hose has been developed in which a spiral gap surrounded by the opposing surfaces of the inner and outer pipes made of soft synthetic resin and the hard synthetic resin reinforcing core wire wound spirally is used as an air layer. Yes.
JP 2001-32970 A JP 2006-132647 A

  However, according to such a synthetic resin hose, an air layer is formed between the inner and outer tubes made of soft synthetic resin by the spiral gap as described above. Since the core wire is present, the volume of the air layer is reduced, and in addition, in order to improve the flexibility, the adjacent reinforcing core wire wound in the length direction of the hose with a constant pitch. Since the outer tube tube wall portion between the top surfaces of the tube is formed on a curved wall surface curved in a concave arc shape toward the inner tube, the volume of the air layer can be further reduced to exhibit a desired heat insulating effect. Have difficulty.

  Moreover, if the reinforcing core wire made of the above-mentioned hard synthetic resin is formed in a hollow shape, a heat insulating action can be exerted by the air layer inside thereof and the weight can be reduced. When a hollow reinforcing core wire is spirally wound on an inner tube made of a soft synthetic resin, the hollow reinforcing core wire is deformed into a flat shape and hardens in a state where there is no hollow portion, and has a hollow reinforcing core wire. There arises a problem that a resin hose cannot be manufactured.

The present invention has been made in view of such problems, and an object thereof is to provide an air layer capable of effectively exhibiting a heat insulating action and have an appropriate curvature and shape retention, and The object is to provide a method capable of easily and inexpensively producing a synthetic resin hose having pressure resistance and suitable for use as a drain hose of an air conditioner or a sheath tube having heat insulation.

In order to achieve the above object, the method of manufacturing a synthetic resin hose according to the present invention includes, as described in claim 1, a semi-molten soft synthetic resin strip on a molding rotating shaft. An inner tube is formed by spirally winding the opposite side portions of the following belt-like material portion on one side and welding them together, and at the same time, a hard synthetic resin is formed on the outer peripheral surface of the inner tube. A hollow reinforcing core wire made of steel is spirally wound at a predetermined pitch while being held in a circular shape by compressed air supplied into the hollow interior, and is integrally welded to the outer peripheral surface of the inner tube. The length of the hose in the hollow reinforcing core wire is welded together by superimposing the opposite side portions of the following belt-like material portion on one side portion of the preceding belt-like material portion on the one side portion of the soft synthetic resin, and integrally welding them. Pressure between adjacent spiral turns And forming an outer tube that the tube wall portions between the helically wound portion adjacent the hollow reinforcing core wire by wrapped helically while supplying air is then expanded in a convex arc shape.

  According to the first aspect of the invention, the semi-molten soft synthetic resin strip is overlapped on one side of the preceding strip member on the molding rotating shaft and the opposite side portion of the following strip member is overlapped. The inner tube is formed by winding it spirally while being welded together, and a hollow synthetic core made of hard synthetic resin is formed on the outer peripheral surface of the inner tube by compressed air supplied to the hollow interior. While being held in shape, spirally wound at a predetermined pitch and integrally welded to the outer peripheral surface of the inner tube, and on this hollow reinforcing core wire, a soft synthetic resin strip is placed on one side of the preceding strip member Since the outer tube is formed while superimposing the opposite side parts of the following strip-shaped material parts and welding them together, the semi-molten hollow reinforcing core wire spirally wound on the inner pipe has a winding force To be deformed into a flat shape by It can be wound in a state of being securely held in a circular cross section while being blocked by the air pressure of compressed air, and on the hollow reinforcing core wire following the spiral winding of the hollow reinforcing core wire on the inner tube When the soft synthetic resin strip for forming the outer tube is spirally wound, the semi-molten hollow reinforcing core wire tends to be deformed into a flat shape by the winding force of the soft synthetic resin strip. This can be reliably prevented by the air pressure supplied to the inside.

  Therefore, the hollow reinforcing core wire is cured while maintaining a circular cross-section, and is welded integrally with the inner and outer pipes between the outer peripheral surface of the inner tube made of the soft synthetic resin and the inner peripheral surface of the outer tube. A synthetic resin hose formed by spirally winding a wire can be easily manufactured, and a wide space portion corresponding to the outer diameter of the hollow reinforcing core wire having a circular cross section is provided between the opposing surfaces of the inner and outer tubes. It is possible to provide a synthetic resin hose that can be provided over and exhibits a heat insulating action by the air layer in the space. In addition, the hollow reinforcing core wire made of a hard synthetic resin can exhibit an excellent pressure resistance and can provide a synthetic resin hose having a high shape retention property at a low cost.

  Furthermore, when forming the outer tube by spirally winding a soft synthetic resin strip on a semi-molten hollow reinforcing core wire spirally wound on the inner tube, the length of the hose in the hollow reinforcing core wire Since the soft synthetic resin strip is wound while supplying compressed air between the spiral winding portions adjacent to each other in the direction, the winding force of the soft synthetic resin strip acting on the semi-molten hollow reinforcing core wire Can be cured while the hollow reinforcing core wire is held in a circular cross section, and the soft synthetic resin band between adjacent spiral winding portions of the hollow reinforcing core wire is reduced by the air pressure. A synthetic resin hose that expands and can further widen the space between the outer tube and the inner tube formed by curing the soft synthetic resin strip and exhibits excellent heat insulation It can be.

  Next, a specific embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a simplified side view of a part of a synthetic resin hose A having heat insulation, and FIG. 2 is an enlarged cross-sectional view of a part thereof. The synthetic resin hose A has an inner pipe 1 made of a soft synthetic resin having an inner circumferential surface formed on a smooth surface having the same diameter over the entire length, and a predetermined outer circumferential surface of the inner pipe 1. A hard synthetic resin hollow reinforcing core wire 2 having a circular cross-section that is spirally wound at a pitch interval and integrally fixed to the outer peripheral surface of the inner tube 1, and a hollow reinforcing core wire 2 wound spirally. And an outer tube 3 made of a soft synthetic resin, which is disposed on the inner tube 1 via the inner surface 1 and is in contact with the top of the hollow reinforcing core wire 2 and fused and integrated with the top. Between the outer peripheral surface of the inner tube 1 and the inner peripheral surface of the outer tube 3, the inner space 4 of the hollow reinforcing core wire 2 wound in the above-described spiral shape is provided. a, and between the hollow reinforcing core wire portions 2a, 2a adjacent to each other in the length direction of the hose, that is, the hollow reinforcing core wire portion 2a wound on the inner tube 1 in the spiral direction first and the hollow reinforcing core wire portion An air layer 4 including a spiral space portion 4b formed between the hollow reinforcing core wire portion 2a wound in the spiral direction following 2a is provided over the entire length.

  The thickness of the inner and outer pipes 1 and 3 made of soft synthetic resin and the thickness of the peripheral wall of the hollow reinforcing core wire 2 made of hard synthetic resin are formed as thin as 1 mm or less. For example, the outer diameter is about 30 mm. In the case of the synthetic resin hose, the thickness of the air layer 4 between the opposing surfaces of the inner and outer tubes 1 and 2 is about 4 mm, and the hitch of the hollow reinforcing core wire 2 is about 9 mm. Is formed. The hollow reinforcing core wire 2 is formed in an elliptical cross section whose major axis direction is in the length direction of the hose, but the cross section may be a perfect circle as shown in FIG. It only needs to have a circular cross section.

  In order to make such a thin and hollow reinforcing core wire 2 interposed between the inner tube 1 and the outer tube 3 while maintaining a circular cross section, a hollow in a semi-molten state at the time of manufacture of the hose is used. When the reinforcing core wire 2 is spirally wound on the inner tube 1, compressed air is supplied to the inside of the hollow, and the hollow reinforcing core wire 2 is expanded into a circular cross section having a predetermined diameter by the air pressure. In this state, the hollow reinforcing core wire 2 is spirally wound on the inner tube 1 to prevent the hollow reinforcing core wire 2 from being deformed into a flat shape by the winding force, and the circular cross section is maintained. It is possible by curing in the state.

  Further, between the outer peripheral surface of the inner tube 1 and the inner peripheral surface of the outer tube 3, the spiral space portion 4b formed between the hollow reinforcing core wire portions 2a and 2a adjacent in the length direction of the hose is The outer wall 3 forming the outer peripheral wall of the spiral space portion 4b is formed in a wide space portion by bending the tube wall portion 3a outwardly into a convex arc shape.

  In this way, the tube wall portion 3a of the outer tube 3 spanned between the hollow reinforcing core wire portions 2a and 2a adjacent to each other in the length direction of the hose is curved in a convex arc shape toward the outside. Is a hollow reinforcing core wire portion 2a wound in the spiral direction in the hollow reinforcing core wire 2 after the hollow reinforcing core wire 2 spirally wound on the inner tube 1 at the time of manufacturing the hose. Then, when forming the outer tube 3 by spirally winding a semi-molten soft synthetic resin band material between the tops of the hollow reinforcing core wire portion 2a wound in the spiral direction, Compressed air is supplied to the space 4b between the inner surface of the soft synthetic resin strip and the adjacent hollow reinforcing core wire portions 2a, 2a, and the soft synthetic resin strip in a semi-molten state is formed into a convex arc shape by the air pressure. This can be done by expanding and curing in this state.

  In this outer tube 3, the tube wall portion 3 b whose inner surface is fused and integrated with the top of the hollow reinforcing core wire 2 is also curved in a convex arc shape along the curved top surface of the hollow reinforcing core wire 2. The hose is provided in a continuous spiral shape in the length direction of the hose, but its inner surface is melted in a state of being laid between the hollow reinforcing core wire portions 2a and 2a adjacent to the tube wall portion 3b in the hose length direction. The tube wall portion 3a curved in the shape of the convex arc, which is integrally attached, is formed to be wider and have a slightly higher protruding height outward.

  The inner tube 1 and the outer tube 3 are made of the same soft synthetic resin, for example, an olefin resin such as polyethylene, polypropylene, EVA resin, or a soft synthetic resin such as vinyl chloride resin. 2 is made of a synthetic resin harder than the soft synthetic resin forming the inner tube 1 and the outer tube 3, for example, a hard synthetic resin having moderate elasticity and hardness such as polyethylene, polypropylene, and hard vinyl chloride, and The soft synthetic resin forming the inner and outer pipes 1 and 3 and the hard synthetic resin that can be fused together.

  The synthetic resin hose A configured as described above is provided between the inner tube 1 and the outer tube 3 between the inner space 4a of the spiral hollow reinforcing core wire 2 and the hollow reinforcing core wire portions 2a and 2a. The spiral space portion 4b has a structure in which only one air layer 4 is provided spirally in the length direction of the hose in parallel with each other through the peripheral wall portion of the hollow reinforcing core wire 2. As shown in FIGS. 3 and 4, the distance between the inner tube 1 and the outer tube 3 is made approximately twice as large as that of the hose A, and two air layers 4 and 4 are interposed between the intermediate tube 5 and the two air layers 4 and 4. Alternatively, a structure may be provided in a state of being overlapped with each other.

  Specifically, this synthetic resin hose A1 is formed by winding the above-mentioned hollow reinforcing core wire 2 made of hard synthetic resin in a spiral shape on a soft synthetic resin inner tube 1 at a predetermined pitch, The core wire 2 is covered with a soft synthetic resin intermediate tube 5 made of the same material as the inner tube 1 and having substantially the same thickness, and the inner peripheral surface portion in contact with the top of the hollow reinforcing core wire 2 is melted integrally with the top. Furthermore, a hollow reinforcing core wire 2A is spirally wound around the intermediate tube 5 at a predetermined pitch, and the hollow reinforcing core wire 2A is covered with a soft synthetic resin outer tube 3 to be hollow. The inner peripheral surface portion of the outer tube 3 in contact with the top of the reinforcing core wire 2A is integrally fused to the top.

  The synthetic resin hose A1 configured as described above includes an inner space 4a of the spiral hollow reinforcing core wire 2 provided between the inner tube 1 and the intermediate tube 5, and a hollow reinforcing core of the hollow reinforcing core wire 2. An air layer 4 formed by the spiral space 4b between the wire portions 2a and 2a is used as an inner air layer, and a spiral hollow reinforcing core wire 2A provided between the outer tube 3 and the intermediate tube 5 is used. It has a double air layer in which the air layer 4 formed by the internal space 4a ′ and the spiral space portion 4b ′ between the hollow reinforcing core wire portions 2a and 2a in the hollow reinforcing core wire material 2A is the outer air layer. These air layers 4 and 4 can provide a further excellent heat insulating effect.

  Furthermore, not only the synthetic resin hose A1 having the two air layers 4 and 4, but the interval between the inner tube 1 and the outer tube 3 is substantially smaller than that of the hose A as shown in FIGS. The structure may be three times as large as that of a synthetic resin hose A2 in which three air layers 4, 4, and 4 are sequentially overlapped via intermediate pipes 5 and 5, A structure having three or more air layers may also be used.

  Next, a method of manufacturing the synthetic resin hose A having the above-described structure will be described with reference to FIGS. 7 to 9. A soft synthetic resin strip 1 such as a semi-molten soft vinyl chloride resin having a constant width and a constant thickness. As is well known, while extruding 'from the forming nozzle 11 of the first extruder, on the base end portion of the metal forming rotating shaft 14, on the opposite side of the following strip-shaped member portion on one side of the preceding strip-shaped member portion The inner pipe 1 is formed by spirally winding the parts at a constant pitch while overlapping and welding together, and in the course of forming the inner pipe 1, the molding nozzle 12 of the second extruder is formed. Formed by the above-mentioned synthetic resin strip 1 'wound on the rotating shaft 14 while extruding a hollow reinforcing core wire 2' having a circular cross section made of a hard synthetic resin such as a semi-molten hard vinyl chloride resin The hollow reinforcing core wire 2 'is fixed on the inner pipe 1 By winding in a spiral manner with a pitch interval, the inner peripheral surface thereof is integrally welded onto the synthetic resin strip 1 '.

At this time, when the semi-molten hollow reinforcing core wire 2 ′ is extruded from the molding nozzle 12 of the second extruder, as shown in FIG. 9, the compressed air supply nozzle 15 is inserted into the hollow of the hollow reinforcing core wire 2 ′. The compressed air 15 is supplied and the hollow reinforcing core wire 2 ′ is held in a hollow circular shape by the air pressure. As described above, when the hollow reinforcing core wire 2 'in a semi-molten state is wound around the inner tube 1 formed on the molding rotating shaft 14 in a spiral manner while applying air pressure to the hollow reinforcing core wire 2'. The hollow reinforcing core wire 2 'is prevented from being deformed into a flat shape by the winding force by air pressure, and can be wound in a state of being held in a circular cross section to form the inner tube 1. The hollow reinforcing core wire 2 integrally fused on the synthetic resin strip 1 'can be spirally provided.

  After the hollow reinforcing core wire 2 'is spirally wound on the inner tube 1 formed on the forming rotary shaft 14, the hollow reinforcing core wire 2' is followed by the forming nozzle 13 of the third extruder. From the above-mentioned synthetic resin strip 1 ', the soft synthetic resin strip 3' in a semi-molten state having a certain width and thickness made of the same synthetic resin is extruded and spirally wound. The hollow reinforcing core wire 2 'is integrally welded to the top portion of the inner surface portion of the hollow reinforcing core wire material 2' which is in contact with the top portion of the spiral wound core wire portion 2a, 2a adjacent to the length direction of the hose. The outer tube 3 is formed by spirally winding at a constant pitch while overlapping and welding the opposite side portions of the succeeding strip-shaped material portion on one side portion of the preceding strip-shaped material portion. Will be formed.

  At this time, the hollow reinforcing core wire 2 'before being cured is pressed by the winding force of the soft synthetic resin strip 3', but the compressed air is compressed in the hollow reinforcing core wire 2 'as described above. Therefore, the hollow reinforcing core wire 2 ′ can be prevented from being deformed into a flat shape by the air pressure. Further, when this soft synthetic resin strip 3 'is spirally wound on the hollow reinforcing core wire 2', the inner surface of the soft synthetic resin strip 3 'and the adjacent hollow reinforcing core wire portions 2a, 2a The compressed air is supplied from the compressed air supply nozzle 16 into the spiral space 4b formed by the gap, and the strip-shaped material part between the adjacent hollow reinforcing core wire parts 2a and 2a is convex outward by the air pressure. By expanding in an arc shape and curing in this state, an outer tube 3 is formed in which the tube wall portion 3a formed of the strip-shaped material portion is curved outwardly in a convex arc shape.

  In this way, a synthetic resin hose having the above-described structure is formed continuously by interposing the hollow reinforcing core wire 2 spirally wound between the soft synthetic resin inner and outer tubes 1 and 3 on the molding rotating shaft 14. While moving the hose toward the tip of the molding rotary shaft 14 and cooling it with the cooling water sprayed from the pipe 17 provided with a number of cooling water injection holes in the course of movement, the hose is extended from the molding rotary shaft 14 The hose A having a predetermined length is obtained by feeding in a direction and cutting it at a desired length or every predetermined length.

The simplified side view which sectioned a part of synthetic resin hose. The expanded sectional view of the one part. The simplified side view which sectioned a part of synthetic resin hose which provided two air layers. The expanded sectional view of the one part. The simplified side view which sectioned a part of synthetic resin hose which provided three layers of air layers. The expanded sectional view of the one part. The simplified top view which shows a manufacturing method. The enlarged plan view. Sectional drawing of the nozzle part of a 2nd extruder. The partial expanded sectional view which shows the modification of this invention synthetic resin hose.

DESCRIPTION OF SYMBOLS 1 Inner tube made from soft synthetic resin 2 Hollow reinforcement core wire 3 Outer tube made from soft synthetic resin
3a Tube wall part 4 Air layer
4a Internal space of hollow reinforced core wire
4b Spiral space

Claims (1)

  A semi-molten soft synthetic resin strip is wound spirally on the rotating shaft while the opposite sides of the following strip are overlapped and welded together on one side of the preceding strip. As a result, the inner pipe is formed and a hollow reinforcing core wire made of hard synthetic resin is held on the outer peripheral surface of the inner pipe at a predetermined pitch while being held in a circular shape by compressed air supplied to the hollow inside. Spirally wound and integrally welded to the outer peripheral surface of the inner tube, and on the hollow reinforcing core wire, a soft synthetic resin strip is placed on one side of the preceding strip member to the opposite side of the strip member The hollow reinforcing core wire is formed by spirally winding the compressed air between the spiral winding portions adjacent to each other in the lengthwise direction of the hose in the hollow reinforcing core wire while overlapping the portions and welding them together. Adjacent spiral winding in Method for producing a synthetic resin hose, wherein a tube wall of which forms an outer tube formed by expansion in a convex arc shape.

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