Heat insulation hose

Abstract

To provide a heat insulation hose which is not only excellent in heat insulation performance and curvature performance, but also can reduce a pressure loss of fluid which circulates in the hose when the hose is curved.SOLUTION: A heat insulation hose A of the present invention has: an inner pipe 1 including a soft resin; a reinforcing linear body 3 arranged on the inner pipe 1, having a first clearance part C having a prescribed width, and including two strip-shaped reinforcing wire rods 2, 2 which are spirally wound with a constant pitch; a heat insulation layer 4 which is formed by spirally winding a band-shaped heat insulation material 4a including a foaming resin in a state that the two strip-shaped reinforcing wire rods 2, 2 constituting the reinforcing linear body 3 are immersed into an inner layer part while having a second clearance part D between opposing end faces of the band-shaped heat insulation material; and an outer pipe 5 including a soft resin which coats the heat insulation layer 4.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a thermal insulated hose suitable for use as a ventilation duct hose for air conditioning equipment in a house or building. [Background technology]

[0002] Conventionally, as described in Patent Document 1, an insulated hose used as a ventilation duct for air conditioning equipment has been known which has a structure comprising a thin-walled inner tube made of soft polyvinyl chloride resin, a reinforcing core wire made of hard polyvinyl chloride resin wound in a spiral shape around the inner tube at a constant pitch, an insulating layer having a constant thickness formed by winding a strip-shaped insulating material made of foamed polyethylene resin with a square cross section around the inner tube with opposing side end faces joined, with the reinforcing core wire embedded in the inner layer, and a thin-walled outer tube made of soft polyvinyl chloride resin covering the insulating layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-3745 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the insulated hose described in Patent Document 1, the space between the inner tube and outer tube is filled with an insulating layer without any gaps, so that when the insulated hose is bent, the bending resistance increases, making it difficult to bend. In addition, when the insulated hose is bent, the inner peripheral wall portion of the hose, which is curved into a concave arc, receives a compressive force in the longitudinal direction, narrowing the gap between adjacent reinforcing core wires, and the pipe wall portion of the inner tube between the reinforcing core wires slackens into a U-shaped cross section in the inner diameter direction of the hose. This slackening deformation causes pressure loss, i.e., a decrease in air blowing capacity (windage loss).

[0005] Therefore, in order to make the insulated hose described in Patent Document 1 into an insulated hose that can obtain a specified air volume even when bent, the inner and outer diameters must be large. For example, if such an insulated hose is used as a humidifier hose, there are problems such as the interference with the work of storing the humidifier hose, together with the refrigerant conduit connecting the indoor and outdoor units of an air conditioner and the drain hose for discharging the drain, in a bundled state within the piping that connects the indoor unit to the outdoor unit through a hole in the wall of the building, and with the work of installing the piping.

[0006] The present invention has been made in consideration of these problems, and an object of the present invention is to provide a thermally insulated hose that not only has excellent thermal insulation properties and bendability, but also reduces the pressure loss of the fluid flowing through the hose when it is bent. [Means for solving the problem]

[0007] The insulated hose of the present invention is an inner tube including a soft resin; a reinforcing wire body including two reinforcing wires wound in a spiral shape at a constant pitch and disposed on the inner tube with a first gap having a predetermined width; an insulating layer formed by spirally winding a strip-shaped insulating material containing a foamed resin while leaving a second gap between the opposing side end faces and while immersing the two reinforcing wires constituting the reinforcing wire body in the inner layer portion; and an outer pipe containing a soft resin covering the heat insulating layer. Effect of the Invention

[0008] The insulated hose of the present invention has a second gap formed between the side end faces of the strip-shaped insulation containing foamed resin, so that when the insulated hose is bent, adjacent strip-shaped insulation materials are prevented from pushing against each other, generating a compressive repulsion force and preventing bending resistance, and the insulated hose has excellent bendability.

[0009] When the insulated hose is bent, the inner pipe portion spanning the second gap formed between the strip-shaped insulation on the inner surface of the inner peripheral wall portion (hereinafter simply referred to as the "inner peripheral wall portion") which is curved into a concave arc, receives a compressive force in the longitudinal direction and sags as it sinks into the second gap, and does not protrude inward (towards the fluid flow passage).This reduces the resistance inside the pipe to the fluid flowing inside the insulated hose, thereby reducing pressure loss, and an insulated hose can be provided which can obtain the desired air volume even if the inner and outer diameters are formed small.

[0010] A first gap is formed between the two reinforcing wires of the reinforcing filament in the insulated hose, and the inner pipe portion spanning this first gap bends smoothly when the insulated hose is bent, giving the insulated hose excellent bendability.

[0011] The insulated hose has a first gap between the reinforcing wires and a second gap in the insulation layer, and the insulation is ensured by the air layers in the first and second gaps, so the insulated hose has excellent insulation properties. The insulated hose also aims to reduce the amount of strip-shaped insulation material used by forming the second gap in the insulation layer, making it lightweight and contributing to global environmental protection by reducing the amount of fossil fuels used as the raw material for the strip-shaped insulation material.

[0012] In the above-mentioned insulated hose, when the outer pipe is sunk into the inner pipe side at the second gap of the insulation layer, the portion of the outer pipe spanning the second gap of the insulation layer at the inner peripheral wall portion when the insulated hose is bent smoothly sunk into the second gap. Therefore, no protrusion is formed on the outer peripheral surface of the inner peripheral wall portion when the insulated hose is bent, and it is possible to prevent the outer diameter from increasing when the insulated hose is bent.

[0013] On the other hand, when the insulated hose is bent, the outer peripheral surface of the outer circumferential wall portion (hereinafter simply referred to as the "outer circumferential wall portion") that curves into a convex arc is stretched, but the outer tube portion that is in a slack state and spans the second gap portion of the insulation layer is expanded to follow, thereby imparting excellent bendability to the insulated hose.

[0014] In the above-mentioned insulated hose, when the inner pipe portion between the reinforcing wires of the reinforcing wire body is curved and the reinforcing wires are displaced in a direction to bring their tips closer to each other at the inner peripheral wall portion that is curved into a concave arc when the insulated hose is bent, the two reinforcing wires of the reinforcing wire body are displaced in a direction to bring their tips closer to each other, which relatively easily displaces the inner pipe portion spanning the second gap of the insulation layer toward the second gap. As a result, when the insulated hose is bent, on the inner peripheral surface of the inner peripheral wall portion, the inner pipe portion spanning the second gap formed between the strip-shaped insulation materials slackens and smoothly sinks into the second gap and does not protrude into the fluid flow path, thereby reducing the intra-pipe resistance to the fluid flowing through the insulated hose and reducing pressure loss. [Brief description of the drawings]

[0015] [Figure 1] 1 is a perspective view of a portion of a thermally insulated hose of the present invention cut away lengthwise; FIG. [Diagram 2] 1 is a cross-sectional view of a portion of an insulated hose. [Diagram 3] FIG. 4 is an enlarged cross-sectional view of a portion of a peripheral wall portion of the hose. [Figure 4] FIG. [Diagram 5] FIG. 4 is an enlarged cross-sectional view of an inner peripheral wall portion of the thermally insulated hose curved in a concave arc shape. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] A specific embodiment of the present invention will be described with reference to the drawings. In Figs. 1 to 3, the heat insulating hose A is composed of a flexible thin-walled inner pipe 1 containing a soft resin, a reinforcing wire body 3 formed by arranging two reinforcing wires 2, 2 containing a hard resin at a certain pitch and spirally wound around the inner pipe 1 at a certain interval, a heat insulating layer 4 formed by spirally winding a strip-shaped heat insulating material 4a made of a foamed resin around the inner pipe 1 at the same pitch as the reinforcing wire body 3 while forming a gap of a certain width between the opposing side end faces and while immersing the two reinforcing wires 2, 2 forming the reinforcing wire body 3 entirely in the inner layer portion, and a flexible thin-walled outer pipe 5 containing a soft resin that covers the heat insulating layer 4.

[0017] The inner pipe 1 and the outer pipe 5 contain soft polyvinyl chloride resin, and the two aligned reinforcing wires 2, 2 constituting the reinforcing wire body 3 contain the same hard polyvinyl chloride resin as the inner and outer pipes 1, 5, but may be made of other thermoplastic resins. Meanwhile, the strip-shaped insulation material 4a constituting the insulation layer 4 contains a foamed polyolefin resin such as a foamed polyethylene resin. The strip-shaped insulation material 4a may be made of other foamed resins.

[0018] 2 and 3, the inner pipe 1 is formed by spirally winding a thin soft resin strip 1' having a constant width and thickness around a rotating shaft (not shown) with a constant pitch while overlapping one side of the preceding soft resin strip 1' with the other side of the preceding soft resin strip 1', so that the parts with more overlaps form a thick pipe wall 1a that rises toward the insulating layer 4, while the parts with less overlaps form a thin pipe wall 1b. Then, inside the inner pipe 1, a fluid flow passage B is formed through which fluids such as air and water flow.

[0019] The reinforcing wire 3 is wound around the thin-walled pipe wall portion 1b of the inner pipe 1, and the thick-walled pipe wall portion 1a is present between adjacent reinforcing wires 3, 3 at a certain pitch, i.e., between the preceding reinforcing wire 3 and the succeeding reinforcing wire 3.

[0020] In addition, a structure may be formed in which a non-overlapping portion and a thick portion overlapped in two layers are formed by spirally winding a soft resin strip, and the above-mentioned reinforcing wire 3 is wound around the non-overlapping portion.

[0021] The two reinforcing wires 2, 2 constituting the reinforcing wire body 3 are wound in parallel with each other around the thin pipe wall portion 1b of the inner pipe 1. The two reinforcing wires 2, 2 have the same shape, and the reinforcing wire 2 has a cross section formed by cutting an ellipse in the minor axis direction or a shape similar thereto, with a base end surface 21 that contacts the inner pipe 1 being flat and a tip portion 22 being formed into a convex arc-shaped portion. By forming the base end surface 21 of the reinforcing wire 2 into a flat surface, the adhesion between the reinforcing wire 2 and the inner pipe 1 is improved, and when the insulated hose A is curved, the strength of the inner pipe portion with which the reinforcing wire 2 is in close contact is increased, so that the inner pipe portion 1C between the reinforcing wires 2, 2 curves relatively smoothly. Furthermore, by forming the tip 22 of the reinforcing wire 2 into a convex arc shape, the first gap C formed between the reinforcing wires 2 is large enough to prevent air convection from occurring inside, ensuring thermal insulation through an air layer, while forming the tip opening C1 of the first gap C to gradually widen, making it possible to smoothly retreat a part of the strip-shaped insulation material 4a constituting the insulation layer 4 into the tip opening C1 of the first gap C when the insulated hose A is bent, thereby making it easier to open the second gap D of the insulation layer 4 and smoothly receiving the part of the inner pipe 1 spanning the second gap D into the second gap D of the insulation layer 4, thereby preventing a part of the inner pipe 1 from protruding into the fluid flow path B. The two reinforcing wires 2 do not have to have the same shape.

[0022] The strip-shaped insulation material 4a made of foamed resin forming the insulation layer 4 has a thickness greater than the height of the reinforcing wire 2 (preferably 2 to 3 times the height of the reinforcing wire 2), and is formed into a horizontally elongated rectangular cross-section having a width greater than the thin-walled pipe wall portion 1b of the inner pipe 1 and narrower than the combined width of the thick-walled pipe wall portion 1a and the thin-walled pipe wall portion 1b. The strip-shaped insulation material 4a is spirally wound around the inner pipe 1 with the same pitch as the reinforcing wires 3, and with a width slightly narrower than the width of the thick pipe wall 1a of the inner pipe 1 between one end face of the preceding strip-shaped insulation material 4a and the other end face of the succeeding strip-shaped insulation material 4a, i.e., between the opposing faces of the strip-shaped insulation materials 4a, 4a, with the two reinforcing wires 2, 2 constituting the reinforcing wire body 3 immersed in the inner layer part of the widthwise center part and with the inner end faces of both ends of the strip-shaped insulation material 4a in contact with the inner pipe 1, to form the insulation layer 4, and a second gap D is formed between the strip-shaped insulation materials 4a, 4a. An air layer is formed in the second gap D. Both ends of the strip-shaped insulation material 4a in the width direction are placed on the thick pipe wall 1a of the inner pipe 1 and wound in a tight contact state, and the second gap D of the insulation layer 4 is formed on the thick pipe wall 1a of the inner pipe 1.

[0023] The thick pipe wall portion 1a of the inner pipe 1 is formed to be slightly harder than the thin pipe wall portion 1b while maintaining flexibility. When the inner pipe portion 1c between the reinforcing wires 2, 2 of the reinforcing wire body 3 is curved inwardly in a convex arc shape at the inner peripheral wall portion A1 when the insulated hose A is curved, and the reinforcing wires 2, 2 are displaced in a direction that brings their tips 22, 22 closer to each other, a stress is applied to the inner pipe portion 1d spanning the second gap D of the insulation layer in the direction of the second gap D. At this time, the thin pipe wall portion 1b of the inner pipe 1 is in close contact with the reinforcing wires 2 and the strip-shaped insulation material 4a of the insulation layer 4, except for the inner pipe portion 1c between the reinforcing wires 2, 2, so that the thin pipe wall portion 1b does not loosen and the above-mentioned stress is reliably transmitted to the thick pipe wall portion 1a, which, even as it loosens, deforms the strip-shaped insulation material 4a of the insulation layer 4 and is smoothly accommodated in the second gap portion D of the insulation layer 4.

[0024] When the strip-shaped insulation 4a forming the insulation layer 4 is spirally wound to cover the aligned reinforcing wires 2, 2, the central part in the width direction of the inner layer (the thick part facing the inner pipe 1) is compressed and deformed by the reinforcing wires 2, 2 to form a groove 6 in which the reinforcing wires 2, 2 are immersed in the inner layer part, and the reinforcing wires 2, 2 are completely contained in this groove 6, and an air layer is formed in the first gap C formed between the reinforcing wires 2, 2 in the groove 6.

[0025] Furthermore, the heat insulating layer 4 is entirely covered by an outer pipe 5 containing soft resin. As shown in Figures 2 and 3, the outer pipe 5 is formed by spirally winding a thin soft resin strip having a constant width and thickness around a forming rotary shaft (not shown) at a constant pitch while overlapping one side of the succeeding soft resin strip on the other side of the preceding soft resin strip.

[0026] The bridging portion 51 spanning the second gap D of the insulating layer in the outer pipe 5 is flexible and is slackened toward the second gap D of the insulating layer 4 and is in a state of being sunk into the second gap D. The bridging portion 51 spanning the second gap D of the insulating layer in the outer pipe 5 is configured such that when the opening of the second gap D that the bridging portion 51 spans expands, the bridging portion 51 follows the expansion of the second gap D, eliminating the slack, and expands, whereas when the opening of the second gap D that the bridging portion 51 spans contracts, the bridging portion 51 becomes even more slack and becomes in a folded state so as to be smoothly stored in the second gap D. Furthermore, since the bridging portion 51 of the outer pipe 5 is immersed in the second gap portion D of the insulation layer 4, the outer pipe 5 is configured not to be displaced relative to the inner pipe 1, the reinforcing wire 3, and the insulation layer 4. Since the outer pipe 5, the inner pipe 1, the reinforcing wire 3, and the insulation layer 4 do not displace relative to one another, deformation of the insulated hose A during use is reduced.

[0027] Next, an example of a manufacturing method of the insulated hose A constructed as described above will be briefly described. A thin-walled strip of semi-molten soft resin having a certain width is extruded from a molding nozzle while being spirally wound at a certain pitch on a molding rotation shaft so that one side of the succeeding strip is overlapped onto one side of the preceding strip and the other side of the succeeding strip are fused together to form a thin-walled flexible inner pipe 1 having alternating thick pipe wall portions 1a and thin pipe wall portions 1b. At the same time, a reinforcing wire body 3 consisting of the two reinforcing wires 2, 2 that are laid in parallel and made of semi-molten hard resin is extruded from another molding nozzle onto the outer circumferential surface of this inner pipe 1 while being spirally wound at a certain pitch around the thin pipe wall portion 1b of the inner pipe 1, and the base end faces 21, 21 of the reinforcing wires 2, 2 are fused to the outer circumferential surface of the thin pipe wall portion 1b.

[0028] Furthermore, a strip-shaped insulation material 4a made of flexible foamed resin and having a horizontally elongated rectangular cross-section whose thickness is greater than the height of the reinforcing wire 2 and whose width is slightly shorter than the sum of the widths of one of the thick pipe wall portions 1a and the thin pipe wall portion 1b of the inner pipe 1 is spirally wound around the reinforcing wires 2, 2 of the reinforcing wire body 3 so that its widthwise central portion covers the reinforcing wires 2, 2 of the reinforcing wire body 3, forming a gap slightly narrower than the width of the thick pipe wall portion 1a on the thick pipe wall portion 1a of the inner pipe 1 between the opposing side end faces of the preceding and succeeding strip-shaped insulation material, and the winding force causes the reinforcing wires 2, 2 forming the reinforcing wire body 3 to compress and deform the inner layer portion of the strip-shaped insulation material 4a, forming an insulation layer having a groove 6 in which the entire reinforcing wires 2, 2 are immersed in the widthwise central portion of the inner layer.

[0029] Subsequently, a thin strip of semi-molten soft resin having a certain width is extruded from another molding nozzle and wound spirally at a certain pitch around the outer circumferential surface of the thermal insulation layer 4 while overlapping one side of the succeeding strip onto the other side of the preceding strip and fusing them together to form the outer pipe 5. When the outer pipe 5 is formed, the bridging portion 51 of the outer pipe 5 spanning the second gap D of the thermal insulation layer falls into the second gap D of the thermal insulation layer 4 due to its own weight when semi-molten, and slackens toward the second gap D and becomes immersed in the second gap D.

[0030] In the above-mentioned insulated hose A, the reinforcing wire body 3 which is wound in a spiral shape at a constant pitch around the inner tube 1 which contains a soft resin is formed by arranging two reinforcing wires 2, 2 in parallel with a small gap therebetween. This increases the pressure resistance of the insulated hose A and provides excellent shape retention. Even when the hose A is bent, it is able to maintain its circular cross-sectional shape without buckling or flattening, thereby providing good fluid flow properties.

[0031] Furthermore, the insulation layer 4 formed by spirally winding strip-shaped insulation material 4a made of foamed resin around the inner pipe 1 at a constant pitch has the reinforcing wires 2, 2 entirely embedded in the inner layer of the spirally wound strip-shaped insulation material 4a, so that the reinforcing wires 2, 2 prevent the insulation layer 4 from moving freely in the longitudinal direction of the hose, thereby maintaining a stable hose shape.

[0032] A first gap C is formed between the reinforcing wires 2, 2 of the reinforcing wire body 3, and a second gap D is formed between the strip-shaped insulation materials 4a, 4a of the insulation layer 4, and the first gap C and the second gap D act as air layers to provide insulation, so that the insulated hose A has excellent insulation properties.

[0033] When the insulated hose A is bent, as shown in Figures 4 and 5, the inner peripheral wall portion A1 of the hose, which is curved into a concave arc, is compressed in the longitudinal direction, and the inner pipe portion 1c between the reinforcing wires 2, 2 is curved inward into a convex arc, displacing the ends 22, 22 of the reinforcing wires 2, 2 in a direction toward each other. In comparison, a stress is applied to the inner pipe portion 1d consisting of the thick pipe wall portion 1a spanning the second gap D of the insulation layer 4, displacing this inner pipe portion 1d into the second gap D, and the inner pipe portion 1d is smoothly accommodated in the second gap D of the insulation layer 4 while deforming the strip-shaped insulation material 4a of the insulation layer 4, even as it slackens. The inner tube 1 is formed with a thick tube wall portion 1a and a thin tube wall portion 1b. The thin tube wall portion 1b improves the flexibility of the inner tube 1, and the thick tube wall portion 1a, which is formed to be harder than the thin tube wall portion 1b, is securely contained within the second gap portion D, so that the inner tube portion 1d does not protrude into the fluid flow passage B side.

[0034] In this way, when the insulated hose A is bent, the thick pipe wall portion 1a (inner pipe portion 1d) of the inner pipe 1 does not protrude toward the fluid flow passage B, so that the internal resistance of the fluid such as air or water (preferably air) flowing through the insulated hose can be reduced, thereby reducing pressure loss.

[0035] Furthermore, when the insulated hose A is bent, the bridging portion 51 of the outer pipe 5 spanning the second gap D of the insulation layer is normally slackened toward the second gap D of the insulation layer 4 and immersed in the second gap D. When the insulated hose A is bent, the outer peripheral surface of the inner peripheral wall portion A1 of the insulated hose A is compressed in the length direction, but the bridging portion 51 of the outer pipe 5 is accommodated in the second gap D of the insulation layer 4 while slackening, whereas the outer peripheral surface of the outer peripheral wall portion A2 of the insulated hose A is stretched, but the bridging portion 51 of the outer pipe 5 stretches with reduced slack to smoothly follow, thereby imparting excellent bending ability to the insulated hose A.

[0036] In this way, the outer diameter of the insulated hose A does not increase even when it is bent, and as described above, the internal resistance of the fluid flowing inside the insulated hose is reduced, thereby reducing pressure loss, so that the necessary amount of fluid can be ensured even when the outer diameter is small.

[0037] Therefore, even when the insulated hose A is used as a humidifier hose, it can be easily stored in a bundled state together with the refrigerant conduit connecting the indoor and outdoor units of an air conditioner and the drain hose for discharging drainage within the piping that connects the indoor unit to the outdoor unit through a hole in the wall of the building, and the piping installation work can be performed. [Explanation of symbols]

[0038] 1 inner tube 1a Thick pipe wall 1b Thin pipe wall 1c Inner tube part 1d Inner pipe part spanning the second gap 2 Reinforcing wire 21 Proximal surface 22 Tip 3 Reinforcing wire 4. Insulation layer 4a Strip insulation 5 Outer tube 51 Crosslinked part A Insulated hose B Distribution path C First gap D Second gap

Claims

1. an inner tube including a soft resin; a reinforcing wire body including two reinforcing wires wound in a spiral shape at a constant pitch and disposed on the inner tube with a first gap having a predetermined width; an insulating layer formed by spirally winding a strip-shaped insulating material containing a foamed resin while leaving a second gap between the opposing side end faces and while immersing the two reinforcing wires constituting the reinforcing wire body in the inner layer portion; and an outer pipe containing a soft resin covering the insulating layer.

2. 2. The insulated hose according to claim 1, wherein the outer pipe is recessed into the inner pipe at the second gap of the insulating layer.

3. 3. The insulated hose according to claim 1, wherein the inner circumferential wall portion of the insulated hose is curved in a concave arc shape when the insulated hose is bent, and the inner pipe portion between the reinforcing wires of the reinforcing wire body is curved, so that the reinforcing wires are displaced in a direction such that their tips approach each other.

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