JP2012097905A - Hose for vacuum cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible tube that has, in particular, a favorable bending character, has superior tensile strength and durability, and can prevent the generation of an air-flow resonance sound.SOLUTION: In the flexible tube 10 in which band-shaped bodies 14 having substantially S-shaped cross sections are spirally wound to the tube, and overlapping parts 14a, 14c of the adjacent band-shaped bodies are integrally adhered to each other with an adhesive 13, the flexible tube is formed of the band-shaped bodies in which a band-shaped inside wall 14d, a rising part 14e and the overlapping part 14a are connected to one another by connecting parts 14g, 14h which are almost circular and constant in thickness. At least part of the inside wall 14d is located in a position far from a hose center line rather than a porion in which the connecting parts 14g, 14h mostly approximate the hose center line.

Description

The present invention relates to a flexible hose. In particular, it is related with the flexible hose used as a suction hose of a vacuum cleaner.

Conventionally, as a flexible hose used for a suction hose or the like of a vacuum cleaner, a flexible hose mainly made of vinyl chloride resin (PVC) has been widely used. For example, a resin-coated reinforcing wire coated with 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-shaped hose wall is formed by spirally winding a formed tape and a hose wall and a reinforcing body are fused and integrated is known.
However, in recent global environmental problems, PVC waste combustion products generate toxic gases or cause acid rain, and there is a tendency to limit their use. Further, when a PVC hose having a resin-coated reinforcing wire is accidentally stepped strongly with a foot, the hard steel wire may be permanently deformed and the hose may be flattened.
Therefore, in the flexible hose, only the polyolefin-based resin is used and the flexible hose is being formed. The polyolefin resin does not have environmental hazards like PVC, and can produce a flexible hose that retains the shape of the hose itself and does not permanently deform. In particular, a polyolefin resin having a higher hardness than soft PVC is preferably used.

An example of such a flexible hose is disclosed in Patent Document 1.
In Patent Document 1, in order to prevent buckling when a hose is bent with a small radius, a joint portion of a strip-shaped body 34 made of polyolefin resin that is spirally wound and overlapped with each other is formed from the strip-shaped body 34. Also disclosed is a hose 30 that is joined by a hot-melt adhesive resin 33 having a high 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 disclosed in Patent Document 1. As shown in FIG. The band-shaped body 34 has a substantially S-shaped cross section, and overlapping portions 34a and 34c that overlap each other when the band-shaped body is wound and are integrated by an adhesive are provided at both ends thereof. Yes. Between the overlapping portions 34a and 34c at both ends of the belt-like body 34, a portion constituting the hose inner peripheral surface side (hereinafter referred to as an inner wall portion 34d) when wound, and a hose outer peripheral surface side when wound. And a rising portion 34e between the inner wall portion and the outer wall portion are provided.

However, the flexible hose 30 as described in the above-mentioned patent document has the following problems, and further improvement has been awaited.
First, as a first problem, improvement of the ease of bending of the hose has been demanded. In the conventional example showing the cross section of the belt-like body in FIG. 6, the corner portion A connecting the overlapping portion 34a and the inner wall portion 34d, and the corner portion connecting the rising portion 34e and the inner wall portion 34d. In part B, the wall thickness was substantially increased. Therefore, the deformation of the corner portions A and B is hindered compared to other portions, so that the hose tends to be relatively difficult to bend. In order to improve the bendability of the hose, it is conceivable to reduce the thickness of the belt-like body as a whole, but the strength, durability, and buckling resistance of the hose, that is, the direction of deterioration of the hose is worsened. However, 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 to a limited range.

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, which may reduce the tensile strength and durability of the hose. There was also a problem that there was.

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 air current interacting with the inner wall of the hose 30. Once the resonance noise is generated, it becomes quite loud and the use of the vacuum cleaner has to be interrupted. Resonance noise is more likely to occur as the flow rate of air flowing through the hose is higher. As a hose for a vacuum cleaner, a hose that does not generate resonance sound even when used at a higher flow rate is desired. It was.

Further, further improvement in the buckling resistance of the hose, that is, the resistance to crushing, has been desired. In the conventional example shown in Patent Document 1, in order to further improve the buckling resistance, the amount of the hot-melt adhesive 33 having high hardness, which is a reinforcement, is increased, or the region to be bonded is widened. The following measures can be considered. However, any of these measures involve an increase in the weight of the hose or a deterioration in the bendability of the hose and cannot be performed without limitation. Therefore, the improvement in the buckling resistance of the hose is not limited. I did n’t.

In addition, there is a quality problem that it is difficult to make the hose easy to bend and feel the same when the hose is bent. That is, in the conventional example, the band 34 wound spirally so as to partially overlap each other is bonded and integrated by the adhesive 33, but the supply amount of the adhesive and the band 34 are wound spirally. Depending on the tension at the time of application and the winding position and direction, as shown in FIGS. 8B and 8C, the adhesive 33 sometimes protrudes to an unnecessary part of adhesion. In the portion bonded by the adhesive 33, the wound belt-like body 34 and the adhesive 33 are bonded together, so that the rigidity of the portion becomes very high. In this way, if a portion that is not originally required to be bonded is bonded, the deformable portion of the band-shaped body 34 that is not bonded becomes relatively narrow, and the hose 30 is bent. It becomes difficult.

In the conventional flexible hose, there is no means for appropriately limiting the width and thickness of the region to be bonded, so the amount of adhesive 33 supplied, the speed of hose molding, the temperature of the adhesive, and the belt shape Due to variations in various conditions during production, such as the tension applied to the body 34 and the degree of pressing, such as its direction, the width and thickness of the formed adhesive layer may vary. There was a case in which the quality of the hose was changed that the feeling when bent or bent was changed. 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 be prominent, making it difficult to obtain a hose with stable quality.

Japanese Patent Laid-Open No. 11-159668

An object of the present invention is to provide a flexible hose that has good bending characteristics, is excellent in tensile strength and durability, and can prevent generation of airflow resonance generated with airflow in a pipe.

As a result of intensive studies to achieve the above object, the inventors have adopted a band having a specific shape in the vicinity of a portion where the band is not bonded, particularly a portion constituting the inner wall portion of the hose. The present inventors have found that the above problems can be solved and have completed the present invention.

That is, the present invention relates to a flexible hose obtained by winding a belt-like body in a spiral shape, and bonding and integrating overlapping portions of the belt-like bodies adjacent to each other with an adhesive, and the cross-section of the belt-like body is substantially S-shaped. The both end portions in the cross section are the overlapping portions, and an inner wall portion that forms the hose inner peripheral surface side at the time of winding and a hose outer peripheral surface side at the time of winding are formed between the both end portions. The outer wall portion and the rising portion between the inner wall portion and the outer wall portion, and the overlapping portion, the inner wall portion and the rising portion have a substantially arc-shaped cross section and a constant thickness. It is a flexible hose characterized by being connected by a certain connection part. (Claim 1)

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 farther from the hose center line than a portion where the connection portion is closest to the hose center line. ).

In the present invention, the band-like body may be provided with a weir-like protrusion at a boundary portion of a region bonded by the adhesive (claim 3).

In the invention according to claim 3, the dam-like projections may be provided on both sides of the strips adjacent to each other so as to face each other (invention 4).

Further, 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, a resin having a higher hardness than the resin constituting the strip may be used as the adhesive.

In the present invention, since the overlapping portion, the inner wall portion, and the rising portion are connected to each other by the 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 easily bent. In addition, the tensile strength and durability can be improved, and the generation of airflow resonance can be prevented.

Moreover, in the invention which concerns on Claim 2, the said inner wall part is made constant thickness, and the at least one part is arrange | positioned in the position far from a hose centerline rather than the part in which the said connection part approaches the hose centerline most. Therefore, the ease of bending of the hose can be improved, the buckling resistance can be improved, and the generation of airflow resonance can be prevented.

In the invention according to claim 3, the band-like body is provided with a weir-like protrusion at a boundary portion of the region bonded by the adhesive, and in the invention according to claim 5, the weir-like protrusion is provided. Since the protrusion is 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 the hose. Further, 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.

In the invention according to claim 4, since the weir-like protrusions are provided on both sides of the adjacent strips so as to face each other, the strips can be easily formed by extrusion molding. Obtainable.

Furthermore, in the invention according to claim 6, since a resin having a hardness higher than that of the resin constituting the belt-like body is used as the adhesive, the buckling resistance can be improved while ensuring the ease of bending of the hose. it can.

1 is a cross-sectional view of a flexible hose according to a first embodiment of the present invention. These are sectional drawings of the strip | belt shaped object of the 1st Embodiment of this invention. These are sectional drawings of the wall surface of the flexible hose which is the 1st Embodiment of this invention. These are sectional drawings of the strip | belt shaped object of the 2nd Embodiment of this invention. These are sectional drawings of the wall surface of the flexible hose which is the 2nd Embodiment of this invention. FIG. 6 is a cross-sectional view of a belt-like body in a conventional example. These are sectional drawings of the wall surface of the flexible hose which is a prior art example. FIG. 4 is a cross-sectional view of a wall surface of a flexible hose that is a conventional example, (a) is a diagram showing a normal adhesion state, (b) is a diagram showing a state where an adhesive protrudes, (c) FIG. 3 is a view showing a state where an adhesive protrudes. These are figures which illustrate the application to the vacuum cleaner of the flexible hose of this invention.

The present invention will be described below with reference to the accompanying drawings.
(See the first embodiment, FIG. 1, FIG. 2, FIG. 3, 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 electric vacuum cleaner main body 40 and the hand operation unit 50 and used as a suction hose.
FIG. 1 shows a cross-sectional structure of a flexible hose 10 according to the first embodiment. The flexible hose 10 is a spirally wound belt-like body 14 shown in FIG. In FIG. 3, sectional drawing of the wall surface part of the flexible hose 10 is shown.

The band-like body 14 is manufactured by extrusion molding so as to have a cross section shown in FIG. 2 using a polyolefin resin as a material. 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 after its cross-sectional shape is fixed, the belt-like body 14 is spirally wound around a guide shaft of a hose manufacturing apparatus (not shown). The belt-like body 14 is manufactured to the flexible hose 10 by winding the adhesive portion 13 between the overlapping portions 14a and 14c adjacent to each other so that the overlapping portion 14a is positioned in the concave portion 14b. The In addition, the belt-shaped body 14 may be formed into a hose by extruding and cooling, wound up on a reel or the like and temporarily stored on a guide shaft at the time of hose molding.

As shown in FIG. 2, the belt-like body 14 has a substantially S-shaped cross-sectional shape, and overlaps with each other when the belt-like body 14 is wound and is bonded and integrated by the adhesive 13. Overlapping portions 14a and 14c are provided. 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 (hereinafter referred to as an outer wall portion) 14f constituting the outer peripheral surface side and a rising portion 14e between the inner wall portion 14d and the outer wall portion 14f are provided. The inner wall portion 14d and the outer wall portion 14f are substantially parallel in cross section with respect to the central axis of the hose, and the inner wall portion 14d is disposed and wound closer to the hose central axis than the outer wall portion 14f. The overlapping portions 14a and 14c and the rising portion 14e are provided such that their cross sections intersect with the hose central axis (desirably so as to form an angle of 45 to 90 degrees). 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 connecting portion having a substantially arc-shaped cross section is provided between the rising portion 14e and the inner wall portion 14d. It is connected smoothly by 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.

Therefore, in this embodiment, since the thickness of the strip 14 is constant from the connection portion 14g to the outer peripheral portion 14f, the deformation of the strip 14 due to the expansion and contraction or bending of the hose 10 is hindered. Since there is no thick part, the hose can be easily bent. Further, since the wall thickness is constant, there is no portion where stress concentration occurs, and deterioration of the tensile strength and durability of the hose can be prevented. 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.

The inner wall portion 14d is provided with a protruding portion 14i that protrudes toward the outer surface of the hose when the strip 14 is wound around the hose 10. By providing the projecting portion 14i, in the state where the belt-like body 14 is wound and molded into the hose 10, the projecting portion 14i of the inner wall portion 14d is more than the portion where the connecting portions 14g and 14h are closest to the hose center line. Is also arranged at a position far from the hose center line. 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.

Therefore, since the hose inner wall portion constituted by the connecting portion 14g, the inner wall portion 14d, and the connecting portion 14h has a so-called corrugated plate shape, the resistance to deformation such that the hose is crushed can be remarkably increased. . Therefore, the buckling resistance of the formed hose, that is, the difficulty of crushing the hose can be improved.

Further, in the present embodiment, the overlapping portion 14a and the inner wall portion 14d are smoothly connected by the connecting portion 14g having a substantially arc-shaped cross section, and the rising portion 14e and the inner wall portion 14d are also substantially connected. Since it is smoothly connected by the connecting portion 14h having an 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. Air disturbance that causes resonance noise generated by airflow often occurs from a non-smooth part such as a corner of the inner wall surface of the hose, and in the present invention, the inner wall surface of the hose can be configured with a smooth surface. According to the embodiment, air disturbance is less likely to occur, and therefore airflow resonance is less likely to occur even when used at a high flow rate.

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 becomes a kind of turbulent state by the concave groove. Airflow is less likely to peel from the inner wall surface of the hose. In a state where the airflow resonance sound is generated, the airflow in the hose is in a kind of pulsation state. The mechanism of airflow resonance generation is that the pulsation in the airflow grows and the generation of resonance sound is caused by the fact that the airflow is repeatedly peeled off or stuck to the wall of the hose, particularly in the bent part of the hose. It is considered to be one of 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. In a vacuum cleaner in which a 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 the 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 belt-like body 14 is performed by filling the region surrounded by the overlapping portion 14a, the dam-like protrusion 14j, the outer wall portion 14f, the overlapping portion 14c, the dam-like protrusion 14m, and the dam-like protrusion 14k with the adhesive 13. And by solidifying the adhesive.

The adhesive 13 applied and injected into the region filled with the adhesive will spread 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 projections 14j, 14k, and 14m can reliably prevent the adhesive 13 from flowing out or protruding into other areas. Accordingly, the adjacent overlapping portions 14a and 14c can be securely bonded and integrated, and the adhesive can be prevented from adhering to the other portions, and the width and thickness of the bonding region can be kept constant. Can do. Therefore, according to this embodiment, it is possible to obtain a flexible hose of stable quality that does not cause variations in the ease of bending of the hose and the feel when bent. In an electric vacuum cleaner, since it is necessary to freely operate the hose and the vacuum cleaner main body by a hand operation unit, it is necessary that the ease of bending of the hose and the feel thereof 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 that of the band-like body 14, and it is desirable to use an adhesive whose hardness is higher than that of the band-like body 14. The material of the strip 14 and the adhesive 13 may be the same, but desirably, for example, when the strip 14 is EVA having a Shore hardness D35, the adhesive 13 has a Shore hardness D60 or a hardness close thereto. A high density polyethylene resin (HDPE) is used.

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 flexibility of the hose 10 itself is increased. The hose buckling due to a small bend can be prevented without damaging it.

(Refer to the second embodiment, FIGS. 4 and 5)
FIG. 4 shows a cross section of the strip-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. Is wound and partly overlapped, and is adhered by the adhesive 23.

In 2nd Embodiment, the strip | belt-shaped body 24 has a substantially S-shaped cross-sectional shape, and comprises the overlapping part 24a, the connection part 24g of a substantially arc-shaped cross section, and the hose inner peripheral surface side when wound. A portion (hereinafter referred to as an inner wall portion) 24d, a connection portion 24h having a substantially arc-shaped cross section, a rising portion 24e, a portion (hereinafter referred to as an outer wall portion) 24f that forms the hose outer peripheral surface side when wound, and an overlapping portion 24c are provided. However, in this embodiment, the inner wall portion 24d has a protruding portion 24i that protrudes toward the outer surface of the hose when the belt-like body 24 is wound around the hose 20. Two are provided. In a state where the belt-like body 24 is wound and molded into the hose 20, the hose inner surface side surface of the protrusion 24i is provided at a position where the distance from the hose center line is farther than the inner peripheral surface of the connection portions 24h and 24g. When the hose 20 is viewed from the inside of the hose, two concave grooves corresponding to the protrusions 24i are formed on the inner wall portion of the hose formed by the connection portion 24g, the inner wall portion 24d, and the connection portion 24h. Yes.

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. A weir-shaped protrusion 24j is provided on the hose outer surface side of the overlapping portion 24a.

As shown in FIG. 5, the dam-like protrusion 24k is arranged to face the end of the overlapping portion 24a, and the dam-like protrusion 24j is arranged to face the overlapping portion 24c. Adhesion of the belt-like body 24 is performed by filling the adhesive 23 in a region surrounded by the overlapping portion 24a, the weir-shaped protrusion 24k, the outer wall portion 24f, the overlapping portion 24c, and the weir-shaped protrusion 24j, and solidifying the adhesive. Is done by doing.

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

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

The arrangement and shape of the weir-like protrusions that prevent the adhesive from protruding outside the adhesive region are not limited to those shown in the first and second embodiments, and prevent the adhesive from flowing out. For example, columnar protrusions may be arranged as long as the shape is effective. The arrangement of the dam-like protrusions may be arranged at the boundary portion of the region to be bonded, but like the dam-like protrusions 14j of the first embodiment and the dam-like protrusions 24k of the second embodiment, It is more desirable to arrange the weir-like projections in a direction that is substantially perpendicular to the center line of the hose to be molded. When winding the hose around the belt, tension is applied to the belt, so that the belt can be wound and the gap between the portions facing the weir-shaped protrusions is narrowed. It is possible to prevent the adhesive from protruding.

Further, the dam-like protrusions can be configured as single dam-like protrusions like the dam-like protrusions 24j of the second embodiment, but the dam-like protrusions 14k and 14m of the first embodiment Thus, it is more desirable to configure with two weir-like protrusions facing each other. 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.

Further, the cross-sectional shape of the belt-shaped body constituting the flexible hose can adopt various cross-sectional shapes as long as it has the characteristics of the present invention in addition to the shapes shown in the respective embodiments. . Furthermore, the kind and hardness of the polyolefin-based resin mentioned in the above embodiments are merely examples, and can be appropriately changed according to the use of the hose itself or required characteristics.

In the first embodiment, a part of the belt-like body 14 is molded with a polyolefin resin having a hardness higher than that of the material of the belt-like body 14, or a part of the belt-like body 14 has a hardness higher than that of the material of the belt-like body 14. A reinforcing core made of a polyolefin-based resin may be provided. In this case, the adhesive 13 may have a low hardness.

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

(Example 2) The flexibility corresponding to the second embodiment is the same as Example 1 except that the cross-sectional shape of the belt-like body is the cross-sectional shape as shown in FIG. I got a hose.

(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.

Regarding the flexible hoses of Example 1, Example 2, and Comparative Example, the ease of bending, the tensile strength, the durability, the buckling resistance, the stability of the quality related to bending, and the difficulty of generating airflow resonance noise were evaluated. did. The evaluation results are shown in Table 1.

The evaluation method for each evaluation item is as follows. The ease of bending was evaluated by the reaction force when bent by hand, and 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 “high” was given if the strength was high and the number of repetitions until breakage was large. With respect to buckling resistance, a visual evaluation test was performed in which the hose was bent 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 evaluated as “good”. Regarding the stability of the quality related to bending, ten samples for bending evaluation were prepared and subjected to sensory evaluation, and those having no variation in evaluation of bendability were evaluated as “good”. Regarding the difficulty of generating the airflow resonance sound, prepare test samples with each hose wound four times with a diameter of 150 mm, and gradually increase the air flow rate to determine whether airflow resonance sound is generated. The test to evaluate was done. The case where no airflow resonance sound was generated up to the maximum testable flow rate, or the case where no airflow resonance sound was generated up to a higher flow rate was judged as “good”.

△標準的 ○良い ◎特に良い

△ Standard ○ Good ◎ Particularly good

As shown in Table 1, Example 1 and Example 2 were superior in comparison with the comparative example.

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, and is industrially applicable. The nature 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.

10, 20, 30 Flexible hose
13, 23, 33 Adhesives 14, 24, 34 Strips 14a, 24a, 34a Overlapping portions 14b, 24b, 34b Recesses 14c, 24c, 34c Overlapping portions 14d, 24d, 34d Inner wall portions 14e, 24e, 34e Rising portions 14f, 24f, 34f Outer wall portions 14g, 24g Connection portions 14h, 24h Connection portions 14i, 24i Protruding portions 14j, 14k, 14m Weir-shaped protrusions 24j, 24k Weir-shaped protrusions 40 Electric vacuum cleaner main body 50 Hand operating section

The objective of this invention is preventing generation | occurrence | production of the airflow resonance sound generated with the airflow in the pipe | tube of the hose for vacuum cleaners .

That is, the present invention is a hose for a vacuum cleaner in which a strip is wound in a spiral shape, and an overlapping portion of the strips adjacent to each other is bonded and integrated with an adhesive, and the cross-section of the strip is approximately It is S-shaped, and both end portions in the cross section are the overlapping portions, and an inner wall portion that forms a hose inner peripheral surface side at the time of winding and an outer peripheral surface of the hose at the time of winding an outer wall portion forming a side rising part is provided between the inner wall and the outer wall portion, and the overlapping portions and the inner wall portion and the rising portion and each other, one lifting the substantially arcuate cross-section connected And at least a part of the inner wall portion is arranged at a position farther from the hose center line than a portion where the connection portion is closest to the hose center line, and the inner wall portion is viewed from the inside of the hose. characterized by forming a concave groove To a hose for the vacuum cleaner. (Claim 1)

In the present invention, the a composition unit in the cross section and the inner wall portion of the strip and the rising portion to each other, are connected by lifting one connecting portion substantially arc-shaped cross section, further, at least a portion of the inner wall portion, Since the connecting portion is disposed at a position farther from the hose center line than the portion closest to the hose center line, and a concave groove is formed in the inner wall portion as viewed from the inside of the hose, the inside of the hose of the airflow flowing in the hose Peeling from the wall surface can be prevented to prevent generation of airflow resonance noise.

Claims (6)

In a flexible hose formed by spirally winding a band-like body, and bonding and integrating the overlapping portions of the band-like bodies adjacent to each other with an adhesive,
The band-like body has a substantially S-shaped cross section, and both end portions in the cross section are the overlapping portions, and an inner wall portion that forms the hose inner peripheral surface side at the time of winding between the both end portions. And an outer wall part that forms the hose outer peripheral surface side during winding, and a rising part between the inner wall part and the outer wall part is provided,
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. The inner wall portion has a constant thickness, and at least a part of the inner wall portion is disposed at a position farther from the hose center line than a portion where the connection portion is closest to the hose center line. Flexible hose. The flexible hose according to claim 1, wherein the band-like body is provided with a weir-like protrusion at a boundary portion of a region bonded by the adhesive. The flexible hose according to claim 3, wherein the weir-shaped protrusions are provided on both sides of the strips adjacent to each other so as to face each other. 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. The flexible hose according to any one of claims 1 to 5, wherein a resin having a hardness higher than that of the resin constituting the strip is used as the adhesive.

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