WO2007138780A1

WO2007138780A1 - Flexible hose

Info

Publication number: WO2007138780A1
Application number: PCT/JP2007/056540
Authority: WO
Inventors: Tokujiro Hayashi; Junya Kurata
Original assignee: Tigers Polymer Corporation
Priority date: 2006-05-30
Filing date: 2007-03-28
Publication date: 2007-12-06
Also published as: JPWO2007138780A1; JP2012097905A; JP5014135B2

Abstract

A flexible hose (10) used for a vacuum cleaner or the like, which has an excellent bending property, tensile strength and durability, and in which occurrence of air stream resonant sound can be prevented. Band-like bodies (14) each having a generally S-shaped section are spirally wound, and the overlapped parts (14a, 14c) thereof adjacent to each other are integrated by an adhesive agent (13). The inside wall part (14d), the rise part (14e) and the overlapped part (14a) of the band-like body are so connected to each other by connection parts (14g, 14h) having a generally arcuate shape and a uniform thickness as to form the hose (10).

Description

Specification

Flexible hose

Technical field

[0001] The present invention relates to a flexible hose. In particular, the present invention relates to a flexible hose used as a suction hose for a vacuum cleaner.

Background art

Conventionally, as a flexible hose used for a suction hose of a vacuum cleaner, a flexible hose mainly made of polyvinyl chloride resin (PVC) has been widely used. For example, a resin-coated reinforcing wire coated with a hard steel wire with PVC is spirally wound to form a helical reinforcing body, and a tube made of soft PVC is coated on the outside of the reinforcing body. A flexible hose having a structure in which a tape made of soft PVC is spirally wound to form a bellows-like hose wall and the hose wall and a reinforcing body are fused and integrated is known.

However, recent global environmental problems tend to place restrictions on the use of PVC waste combustion products that generate toxic gases or cause acid rain. Also, PVC hoses with reinforced resin-coated reinforcing wires can be used if you accidentally step on them with your feet.

The hard steel wire may be permanently deformed and the hose may become flat.

In view of this, in the case of a flexible hose, a transition is being made to molding a flexible hose using only polyolefin resin. Polyolefin resin does not have environmental hazards like PVC, and can produce a flexible hose that retains its hose shape and does not become permanently deformed. In particular, polyolefin resin having higher hardness than soft PVC is preferably used.

[0003] As such a flexible hose, for example, there is one disclosed in Patent Document 1.

In Patent Document 1, in order to prevent buckling when a hose is bent with a small radius, a joined portion of a strip 34 made of polyolefin-based resin that is spirally wound and overlapped with each other is described. Also disclosed is a hose 30 that is bonded with a hot-melt adhesive resin 33 having a higher hardness and used as a reinforcement. (See Figure 7)

Fig. 6 shows a cross-sectional view of the belt-like body 34 in the conventional flexible hose shown in Patent Document 1. The The band-shaped body 34 has a substantially S-shaped cross section, and overlapping portions 34a and 34c are provided at both ends thereof, which overlap each other when the band-shaped body is wound, and are bonded and integrated by an adhesive. Yes. Between the overlapping portions 34a and 34c at both ends of the belt-like body 34, a portion constituting the inner peripheral surface side of the hose (hereinafter referred to as an inner wall portion 34d) when wound and an outer peripheral surface of the hose when wound A side portion (hereinafter referred to as an outer wall portion 34f) and a rising portion 34e between the inner wall portion and the outer wall portion are provided.

Patent Document 1: Japanese Patent Laid-Open No. 11-159668

[0004] However, the flexible hose 30 described in the above-mentioned patent document has the following problems, and further improvement has been awaited.

The first challenge was to improve the ease of bending of the hose. In the conventional example in which the cross section of the strip is shown in FIG. 6, the corner portion A connecting the overlapping portion 34a and the inner wall portion 34d and the corner connecting the rising portion 34e and the inner wall portion 34d are shown. In part B, the wall thickness was substantially increased. Therefore, the deformation of the corner parts A and B is hindered compared to the other parts, and the hose tends to be relatively difficult to bend. In order to improve the ease of bending of the hose, it may be possible to reduce the thickness of the strip as a whole, but the direction of the hose strength, durability, buckling resistance, that is, the tendency to collapse is worsened. For this reason, there is a limit to the reduction in the thickness of the belt-like body, and the improvement of the bendability of the hose has been limited.

[0005] In addition, when such a band 34 has corner portions A and B, when the hose 30 is bent, stress concentration tends to occur in the vicinity of the portion, and the tensile strength and durability of the hose 30 are increased. There was also a problem that there was a risk of lowering.

[0006] Further, in the conventional flexible hose, when the completed hose is used, a sharp resonance sound such as a whistling sound may be generated due to the interaction of the air flow with the inner wall of the hose 30. there were. Once resonant noise is generated, it becomes powerful and loud noise, so the use of the vacuum cleaner has to be interrupted. The generation of resonance noise occurs as the flow velocity of the air flowing through the hose increases. As a hose for a vacuum cleaner, a hose that does not generate resonance noise even when used at a higher flow velocity is desired. And

[0007] Further, there has been a demand for further improvement in the buckling resistance of the hose, that is, the resistance to crushing. Patent text In the conventional example shown in Appendix 1, in order to further improve the buckling resistance, the amount of the hot-melt adhesive 33 with high hardness, which is a reinforcement, is increased or the bonding area is increased. Can be considered. However, none of these measures can be performed without limitation because the hose weight increase is accompanied by a deterioration in the ease of bending of the hose. Therefore, the improvement in the buckling resistance of the hose is limited. I was forced to give power.

[0008] Further, there is a quality problem that it is difficult to make the hose bendable and feel the same when it is bent. That is, in the conventional example, the band 34 wound spirally so as to partially overlap each other is bonded together by the adhesive 33, but the supply amount of the adhesive and the band 34 are spirally wound. Depending on the tension at the time of winding in the shape and the winding position 'direction, as shown in FIGS. 8 (b) and (c), the adhesive 33 sometimes protrudes to the part where bonding is unnecessary. In the part bonded by the adhesive 33, the wound strip 34 and the adhesive 33 are bonded to the body, so that the rigidity of the part is very high. In this way, if a part that is not originally required to be bonded is bonded, the unbonded deformable part of the band 34 will be relatively narrowed accordingly, and the hose 30 will become relatively narrow. Becomes difficult to bend.

[0009] In the conventional flexible hose, there is no means for appropriately limiting the width and thickness of the bonded area, so the supply amount of the adhesive 33, the hose forming speed, the adhesive The width and thickness of the adhesive layer formed may vary due to variations in various conditions during production, such as the temperature of the belt, the tension applied to the belt 34, and the degree of pressing, such as the direction of the belt. As a result, the ease of bending of the hose and the feel when bent may change the quality of the hose. In particular, when high-density polyethylene (HDPE) or the like having a relatively high hardness is used as an adhesive, this problem is likely to become prominent, making it difficult to obtain a hose with stable quality.

Disclosure of the invention

Problems to be solved by the invention

[0010] An object of the present invention is to provide a flexible hose having good bending characteristics, excellent tensile strength and durability, and capable of preventing the generation of airflow resonance generated with the airflow in the pipe. There is to do. Means for solving the problem

[0011] As a result of intensive investigations to achieve the above-mentioned object, the inventors have found that the band-shaped body has a specific shape in the vicinity of the portion to which the band-shaped body is not bonded, particularly the portion constituting the inner wall portion of the hose. It has been found that the above-mentioned problems can be solved by adopting a body, and the present invention has been completed.

[0012] That is, the present invention provides a flexible hose in which a belt-like body is wound spirally, and an overlapping portion of the belt-like bodies adjacent to each other is bonded and bonded together with an adhesive. Is substantially S-shaped, and both end portions in the cross section are the overlapping portions, and an intermediate wall portion forming a hose inner peripheral surface side at the time of winding, Are provided with an outer wall portion that forms the outer peripheral surface side of the hose, and a rising portion between the inner wall portion and the outer wall portion, and the overlapping portion, the inner wall portion, and the rising portion are substantially arc-shaped. A flexible hose characterized by being connected by a connecting portion having a cross section and a constant wall thickness. (Claim 1)

[0013] In the present invention, the inner wall portion may have a constant thickness, and at least a part of the inner wall portion may be disposed at a position where the hose center line force is farther from the portion where the connection portion is closest to the hose center line ( Claim 2).

[0014] Further, in the present invention, the belt-like body may be provided with a weir-like protrusion at a boundary portion of a region bonded by the adhesive (Claim 3).

[0015] Further, in the invention according to claim 3, the weir-shaped protrusions may be provided on both sides of the strips adjacent to each other so as to face each other (claim 4). ).

[0016] In the invention according to claim 3, the weir-like protrusion may be provided so as to protrude in a direction substantially perpendicular to the hose center line (invention 5).

In the present invention, it is also possible to use, as the adhesive, a resin having a hardness higher than that of the resin constituting the belt-like body (Claim 6).

The invention's effect

In the present invention, the overlapping portion, the inner wall portion, and the rising portion are connected to each other by a connection portion having a substantially arc-shaped cross section and a constant thickness in the cross section of the belt-like body. The hose is easy to bend and improves the tensile strength and durability. Generation of flow resonance sound can be prevented.

[0019] Further, in the invention according to claim 2, the inner wall portion has a constant thickness, and at least a part of the inner wall portion is located at a position farther from the hose center line force than a portion where the connection portion is closest to the hose center line. Since it is arranged, it is possible to improve the ease of bending of the hose, improve the buckling resistance, and prevent the generation of airflow resonance noise.

[0020] In the invention according to claim 3, the belt-like body is provided with a weir-like protrusion at a boundary portion of the region bonded by the adhesive, and in particular, in the invention according to claim 5, Since the weir-shaped protrusions are provided so as to protrude in a direction substantially perpendicular to the hose center line, it is possible to reliably prevent the adhesive from protruding and to improve the ease of bending of the hose. Furthermore, the quality of the hose can be stabilized so that the ease of bending and the feel of bending of the hose are uniform throughout the hose.

[0021] Further, in the invention according to claim 4, since the weir-like protrusions are provided on both sides of the strips adjacent to each other so as to face each other, the strip-shaped body is extruded. Can also be easily obtained.

[0022] Further, in the invention according to claim 6, since the resin having a hardness higher than that of the resin constituting the belt-like body is used as the adhesive, the hose can be easily bent and the buckling resistance can be secured. It can improve the sex.

Brief Description of Drawings

[0023] FIG. 1 is a cross-sectional view of a flexible hose according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a belt-like body according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view of the wall surface of the flexible hose according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view of a band according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of a wall surface of a flexible hose according to a second embodiment of the present invention.

FIG. 6 is a cross-sectional view of a belt-like body in a conventional example.

FIG. 7 is a cross-sectional view of a wall surface of a conventional flexible hose.

FIG. 8 is a cross-sectional view of a wall surface of a conventional flexible hose, (a) is a diagram showing a normal adhesive state, and (b) is a diagram showing a state where the adhesive protrudes. (C) is a view showing a state where the adhesive protrudes. [9] Description of _c symbols is a diagram illustrative of the application of the vacuum cleaner of the flexible hose of the present invention

[0024] 10, 20, 30 Flexible hose

13, 23, 33 Adhesive

14, 24, 34 Band

14a, 24a, 34a Overlapping part

14b, 24b, 34b recess

14c, 24c, 34c Overlap

14d, 24d, 34d inner wall

14e, 24e, 34e Rising part

14f, 24f, 34f outer wall

14g ゝ 24g

14h, 24h

14i ゝ 24i Projection

14j, 14k, 14m Weir-shaped protrusion

24j, 24k Weir-shaped protrusion

40 Vacuum cleaner body

50 Hand control

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described with reference to the accompanying drawings.

(Refer to the first embodiment, Fig. 1, Fig. 2, Fig. 3, and Fig. 9)

FIG. 9 shows an example in which the flexible hose 10 according to the first embodiment of the present invention is applied to a vacuum cleaner. The flexible hose 10 is connected between the connection port 41 of the vacuum cleaner main body 40 and the hand operation unit 50, and is used as a suction hose.

FIG. 1 shows a cross-sectional structure of a flexible hose 10 according to the first embodiment, and the flexible hose 10 is obtained by spirally winding a belt-like body 14 having a cross section shown in FIG. FIG. 3 shows a cross-sectional view of the wall portion of the flexible hose 10.

[0026] The strip 14 is extruded so as to have a cross section shown in FIG. 2 using a polyolefin resin as a material. Manufactured by molding. Examples of the polyolefin resin include polypropylene resin (PP), polyethylene resin (PE), and ethylene vinyl acetate copolymer resin (EVA). The extruded belt-like body 14 is cooled and its cross-sectional shape is fixed, and is then spirally wound around a guide shaft of a hose manufacturing apparatus (not shown). The band-like body 14 is wound so that the overlapping portion 14a is positioned in the concave portion 14b, and the flexible hose 10 is filled by adhering an adhesive 13 between the overlapping portions 14a and 14c adjacent to each other. To be manufactured. The belt-like body 14 may be formed by extruding and cooling, wound up on a reel or the like and temporarily stored on a guide shaft at the time of hose formation, and forming into a hose.

As shown in FIG. 2, the band-like body 14 has a substantially S-shaped cross-sectional shape, and the both ends overlap each other when the band-like body 14 is wound, and are bonded and integrated by the adhesive 13. There are provided overlapping portions 14a and 14c. Between the overlapping portions 14a and 14c provided at both ends of the belt-like body 14, a portion (hereinafter referred to as an inner wall portion) 14d constituting the hose inner peripheral surface side when wound, and a hose when wound A portion constituting the outer peripheral surface side (hereinafter referred to as an outer wall portion) 14f and a rising portion 14e between the inner wall portion 14d and the outer wall portion 14f are provided. The cross sections of the inner wall portion 14d and the outer wall portion 14f are provided substantially parallel to the central axis of the hose, and the inner wall portion 14d is arranged near the hose central axis and wound. The overlapping portions 14a and 14c and the rising portion 14e are provided so that their cross sections intersect with the hose center axis (preferably 45 degrees force and 90 degrees angle). The overlapping portion 14a and the inner wall portion 14d are smoothly connected by a connecting portion 14g having a substantially arc-shaped cross section, and the rising portion 14e and the inner wall portion 14d are connected having a substantially arc-shaped cross section. It is connected smoothly by part 14h. In the present invention, the outer wall portion 14f, the rising portion 14e, the connection portion 14h, the inner wall portion 14d, and the connection portion 14g are smoothly connected with a constant thickness.

Accordingly, in the present embodiment, the thickness of the belt-like body 14 is constant from the connecting portion 14g to the outer peripheral portion 14f, so that the belt-like body 14 accompanying expansion / contraction or bending of the hose 10 is constant. Since the thickness of the wall that prevents the deformation of the material is not present, it can be bent easily! Furthermore, since the wall thickness is constant, there is no part where stress concentration occurs. This prevents the hose's tensile strength and durability from deteriorating. In view of the object of the present invention, it is particularly important to keep the thickness of the connecting portions 14g and 14h constant. [0029] Further, the inner wall portion 14d is provided with a protruding portion 14i that protrudes toward the outer surface of the hose when the belt-like body 14 is wound around the hose 10. By providing the projecting portion 14i, the projecting portion 14i of the inner wall portion 14d is a portion where the connecting portions 14g and 14h are closest to the hose center line in a state where the strip 14 is wound and formed into the hose 10. The hose center line force is also arranged at a far position. That is, when the hose 10 is viewed from the inside of the hose, a concave groove corresponding to the protruding portion 14i is formed in the hose inner wall portion constituted by the connecting portion 14g, the inner wall portion 14d, and the connecting portion 14h.

[0030] Therefore, the hose inner wall portion composed of the connecting portion 14g, the inner wall portion 14d, and the connecting portion 14h has a so-called corrugated plate shape, so that the resistance to deformation that causes the hose to collapse is remarkably increased. Can be increased. Therefore, it is possible to improve the buckling resistance of the formed hose, that is, the difficulty of crushing the hose.

[0031] Further, in the present embodiment, the force between the overlapping portion 14a and the inner wall portion 14d is smoothly connected by the connecting portion 14g having a substantially arc-shaped cross section, and between the rising portion 14e and the inner wall portion 14d. However, since it is smoothly connected by the connecting portion 14h having a substantially arc-shaped cross section, the inner wall surface of the hose 10 can be constituted by a smooth surface, and there is no corner portion as seen in the conventional example. In the present invention, the hose inner wall surface can be configured with a smooth surface because the disturbance of the air that causes resonance sound generated by the airflow often occurs from a non-smooth portion such as a corner of the hose inner wall surface. According to the embodiment, it is difficult for air disturbance to occur. Therefore, even when used at a high flow velocity, airflow resonance is hardly generated.

[0032] Furthermore, in this embodiment, since the concave groove corresponding to the protrusion 14i is formed on the inner wall surface of the hose, the boundary layer region of the airflow flowing inside the hose by this concave groove is of various types. It becomes a flow state, and the airflow is also separated from the inner wall surface force of the hose. When airflow resonance is generated, the airflow in the hose is in a kind of pulsation. Especially when the hose is bent, the hose wall force is repeatedly peeled off or stuck, causing pulsations in the airflow to grow and the generation of resonance noise. It is considered one of the mechanisms. Therefore, according to the present embodiment, since the separation of the airflow is prevented, the generation of the airflow resonance sound can be prevented even when the hose is used at a higher flow rate. For vacuum cleaners where high-speed airflow passes through the hose, It is particularly desired that no airflow resonance sound is generated up to a higher flow velocity, and this embodiment can be applied particularly favorably to an electric vacuum cleaner.

Furthermore, in the present embodiment, weir-like protrusions are provided at the boundary between the regions bonded by the adhesive to prevent the adhesive 13 from flowing out of the region. That is, a weir-like protrusion 14j that protrudes in a direction substantially perpendicular to the center line of the hose 10 to be molded is provided at the end of the overlapping portion 14a of the strip 14. A weir-like protrusion 14k is provided on the hose outer surface side of the overlapping portion 14a, and a weir-like protrusion 14m is provided on the hose inner surface side of the overlapping portion 14c.

FIG. 3 is a cross-sectional view of the wall surface of the hose 10. The overlapping portions 14 a and 14 c of the adjacent strips 14 are overlapped and bonded and integrated by the adhesive 13. The weir-shaped protrusion 14j is disposed to face the hose inner surface of the outer wall 14f, and the weir-shaped protrusion 14k and the weir-shaped protrusion 14m are disposed to face each other. Adhesion of the strip 14 is performed by filling the region surrounded by the overlapping portion 14a, the weir-shaped protrusion 14j, the outer wall portion 14f, the overlapping portion 14c, the weir-shaped protrusion 14m, and the weir-shaped protrusion 14k with the adhesive 13. This is done by solidifying the adhesive.

[0035] The adhesive 13 applied and injected into the region filled with the adhesive spreads to other regions as the strip 14 is wound and the gap between the overlapping portions 14a and 14c becomes smaller. However, in the present invention, the weir-like protrusions 14j, 14k, and 14m can reliably prevent the adhesive 13 from flowing out or protruding into other areas. Therefore, it is possible to securely bond the adjacent overlapping portions 14a and 14c, and to prevent the adhesive from adhering to the other portions, and the width and thickness of the bonding area are constant. Can be kept. Therefore, according to the present embodiment, it is possible to obtain a flexible hose with stable quality that does not vary in the ease of bending of the hose and the feel when bent. In an electric vacuum cleaner, it is necessary to freely operate the hose and the main body of the vacuum cleaner with the hand control unit, and therefore it is necessary that the ease of bending and the feel of the hose are uniform and uniform. Therefore, the flexible hose of the present embodiment can be particularly suitably applied to a vacuum cleaner.

The adhesive 13 is a hot-melt adhesive made of the same polyolefin resin as the strip 14 It is desirable to use an agent whose hardness is higher than that of the strip 14. The material of the strip 14 and the adhesive 13 may be the same, but preferably, for example, when the strip 14 is EVA having a Shore hardness D35, the adhesive 13 has a Shore hardness D60 or a value close thereto. High density polyethylene resin (HDPE) having a hardness of

[0037] By making the hardness of the adhesive 13 higher than the hardness of the belt-like body 14, the adhesive 13 having a relatively high hardness functions as a reinforcing body of the belt-like body 14 having a relatively low hardness, and the hose 10 itself Buckling of the hose due to a small bend can be prevented without impairing the flexibility.

[0038] (Refer to the second embodiment, FIGS. 4 and 5)

FIG. 4 is a cross-sectional view of the band-shaped body 24 constituting the flexible hose 20 according to the second embodiment of the present invention, and FIG. 5 is a cross-sectional view of the wall surface of the flexible hose 20, 24 shows a state in which a part 24 is wound and a part of the parts 24 are overlapped and adhered by the adhesive 23.

[0039] In the second embodiment, the belt-like body 24 has a substantially S-shaped cross-sectional shape, an overlapping portion 24a, a connection portion 24g having a substantially arc-shaped cross section, and an inner peripheral surface of the hose when wound. Part constituting the side (hereinafter referred to as inner wall part) 24d, connecting part 24h having a substantially arcuate cross section, rising part 24e, part constituting the outer peripheral surface side of the hose when wound (hereinafter referred to as outer wall part) 24f, overlapping part 24c In this embodiment, the inner wall 24d has a protrusion that protrudes toward the outer surface of the hose 20 when the belt 24 is wound around the hose 20. Two parts 24 i are provided. In the state where the belt-like body 24 is wound and formed into the hose 20, the surface of the hose inner surface of the protrusion 24i is located at a position farther from the hose center line than the inner peripheral surface of the connection portions 24h and 24g. When the hose 20 is also seen in the hose internal force, two concave grooves corresponding to the protrusions 24i are formed in the hose inner wall portion composed of the connection portion 24g, the inner wall portion 24d, and the connection portion 24h. ing.

[0040] Further, on the inner surface side of the hose 20 of the outer wall portion 24f of the belt-like body 24, a dam-like protrusion 24k is provided that protrudes in a direction substantially perpendicular to the center line of the hose 20 to be molded. Further, a weir-shaped protrusion 24j is provided on the outer surface of the hose of the overlapping portion 24a.

[0041] As shown in FIG. 5, the weir-shaped protrusion 24k is disposed to face the end of the overlapping portion 24a, and the weir-shaped protrusion 24j is disposed to face the overlapping portion 24c. ing. Adhesion of the belt-like body 24 is performed by overlapping part 24a, weir-like protrusion 24k, outer wall part 24f, overlapping part 2 This is done by filling the area surrounded by 4c and the weir-like protrusion 24j with the adhesive 23 and solidifying the adhesive.

[0042] Also in the second embodiment, the same bending ease as in the first embodiment can be improved, the tensile strength and durability are excellent, the buckling resistance is excellent, and the bending characteristics and the feel of bending are concerned. In particular, the quality is stable and it is possible to prevent the generation of airflow resonance generated with the airflow in the pipe. In particular, in the second embodiment, since the two protruding portions 24i are provided on the inner wall portion 24d, the flexibility of the flexible hose and the buckling resistance can be greatly improved.

(Other Embodiments) The flexible hose according to the present invention is not limited to the above-described embodiments, and can be variously modified within the scope of the gist thereof.

[0044] The arrangement and shape of the weir-shaped protrusions that prevent the adhesive from protruding outside the adhesive region are not limited to those shown in the first and second embodiments, and the adhesive flows out. For example, columnar protrusions may be arranged as long as the shape has an effect of preventing the above. The weir-like protrusions may be arranged at the boundary of the region to be bonded, but like the weir-like protrusions 14j of the first embodiment and the weir-like protrusions 24k of the second embodiment It is more desirable to arrange the dam-like projections in a direction that is substantially perpendicular to the center line of the hose to be molded. When the hose is wound around the belt, tension is applied to the belt, so that the belt can be wound and the gap between the weir-shaped protrusions and the part facing it becomes narrower. It is possible to prevent the adhesive from protruding.

[0045] Further, the weir-like protrusion can be configured by a single dam-like protrusion like the weir-like protrusion 24j of the second embodiment. The weir-like protrusion 14k of the first embodiment and It is more desirable to configure with two weir-like protrusions facing each other, such as 14m. By making the two weir-like protrusions facing each other, the height of each of the weir-like protrusions can be lowered, and the process of forming the band-like body by extrusion molding becomes easier.

[0046] In addition to the shape shown in each of the embodiments, the cross-sectional shape of the belt-shaped body constituting the flexible hose may have various cross-sectional shapes as long as it has the characteristics of the present invention. be able to. Furthermore, the kind and hardness of the polyolefin resin referred to in each of the above embodiments are examples, and can be appropriately changed according to the use of the hose itself or required characteristics. [0047] In the first embodiment, a part of the strip 14 is molded with a polyolefin-based resin having a hardness higher than that of the material of the strip 14, or a material of the strip 14 is formed on a part of the strip 14. In this case, it is possible to provide a reinforcing core made of a polyolefin resin having a higher V and hardness. In this case, the adhesive 13 can be made of a low hardness.

Example

(Embodiment 1) A belt-like body having a cross-sectional shape as shown in FIG. 2 and having a wall thickness of 0.8 mm from the connecting portion 14g to the outer wall portion 14f has a hardness of Shore hardness D35. Created by extruding EVA resin, wound the strip, and bonded the overlapped part with HDPE resin with Shore hardness D60, with an inner diameter of 35 mm and outer diameter equivalent to the first embodiment A 43 mm flexible hose was obtained.

(Example 2) [0049] Except that the cross-sectional shape of the belt-like body is a cross-sectional shape as shown in Fig. 4, it corresponds to the second embodiment, which is the same as Example 1. A flexible hose was obtained.

[0050] (Comparative Example) A conventional flexible hose was obtained which was the same as Example 1 except that the cross-sectional shape of the strip was the cross-sectional shape shown in FIG.

Example [0051] Regarding the flexible hose of Example 2 and Comparative Example, it is easy to bend, tensile strength, durability, buckling resistance, stability of quality regarding bending, and difficulty in generating air flow resonance noise. Was evaluated. Table 1 shows the evaluation results.

[0052] The evaluation method of each evaluation item is as follows. The ease of bending was evaluated based on the reaction force when bent by hand. The smaller the reaction force when bending the hose into a predetermined bending shape, the better. With regard to the evaluation of tensile strength and durability, strength and durability tests were conducted, and “good” was given when the strength was high and the number of repetitions until breakage was large. Regarding the buckling resistance, a visual evaluation test was performed to bend the hose to a small bending radius, and the one that did not collapse the cross section of the hose when bent to a small bending radius was judged as “good”. Regarding the stability of the quality related to bending, we prepared 10 samples for bending evaluation and conducted sensory evaluations.

" Regarding the difficulty of generating airflow resonance noise, prepare a test sample in which each hose is wound 4 times with a diameter of 150 mm, and gradually increase the air flow rate while checking whether airflow resonance noise is generated. The test which evaluates was conducted. Up to the maximum flow rate that can be tested “Good” means that no airflow resonance sound was generated, or that airflow resonance sound was not generated up to a higher flow rate.

[0053] [Table 1]

△ Standard 〇Good ◎ Particularly good

[0054] As shown in Table 1, Example 1 and Example 2 were evaluated better than the comparative example. Industrial applicability

[0055] Therefore, according to the present invention, it is possible to provide a flexible hose having particularly good bending characteristics, excellent tensile strength and durability, and capable of preventing the generation of airflow resonance noise. Industrial applicability is high. In particular, a hose suitable as a flexible hose applicable to a vacuum cleaner can be provided, and the utility value is high.

Claims

The scope of the claims

[1] In a flexible hose in which a strip is wound in a spiral shape and the overlapping portions of the strips adjacent to each other are bonded together by an adhesive,

The strip has a substantially s-shaped cross section, and both end portions of the cross section are the overlapping portions, and an inner hose inner peripheral surface side is formed between the both end portions during winding. A wall, an outer wall that forms the outer peripheral surface of the hose when wound, and a rising portion between the inner wall and the outer wall.

The flexible hose is characterized in that the overlapping portion, the inner wall portion, and the rising portion are connected to each other by a connection portion having a substantially arc-shaped cross section and a constant thickness.

[2] The request is characterized in that the inner wall portion has a constant thickness, and at least a part of the inner wall portion is arranged at a position where the hose center line force is farther from the portion where the connection portion is closest to the hose center line. Item 2. A flexible hose according to item 1.

[3] The flexible hose according to claim 1, wherein the belt-like body is provided with a weir-like protrusion at a boundary portion of a region bonded by the adhesive.

4. The flexible hose according to claim 3, wherein the dam-like protrusions are provided on both sides of the strips adjacent to each other so as to face each other.

5. The flexible hose according to claim 3, wherein the weir-shaped protrusion is provided so as to protrude in a direction substantially perpendicular to the hose center line.

[6] The hardness is higher than that of the resin constituting the belt-like body, and the resin is used as the adhesive, and according to any one of claims 1 and 5 The flexible hose as described.