JP2001004075A - Flexible hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve adhesive strength of an inner tube and an outer tube regardless of a monofilament material by coating a monofilament surface with a synthetic resin having an excellent adhesive property with resins of the inner/ outer tubes, and contacting a coating layer with the inner/outer tubes. SOLUTION: A circular section monofilament 3 is wound between resin inner tube 1 and outer tube 2. A surface of the monofilament 3 is coated with a soft synthetic resin having an excellent adhesive property with resin of the inner tube 1 and the outer tube 2, and a coating layer 3a is contacted with the inner tube 1 and the outer tube 2. A core part of the monofilament 3 is molded, for example, from a lightweight material having a low specific gravity such as polypropylene, and for example, a synthetic resin material being harder than the core part and having high strength and high rigidity such as polyethylene terephthalate is desirably used as the coating layer 3a. When using the synthetic resin material being harder than the surface and having high strength and high rigidity for the surface of the lightweight material monofilament 3 as the coating layer 3a, since rigidity of the whole monofilament 3 can be improved, strength of the whole hose can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible hose in which a resin monofilament shaped like a coil spring is wound between a resin inner tube and an outer tube.

[0002]

2. Description of the Related Art Conventionally, as this kind of flexible hose, for example, as disclosed in Japanese Utility Model Publication No. 63-46783, a drawn monofilament made of a thermoplastic resin is wound around the outer peripheral surface of an inner tube. Outer tube is coated and laminated on the outer circumference
By integrating the inner and outer tubes and the coil spring, there is a case in which there is no springback, and even if the tube is crushed, it can return to the original state immediately.

[0003]

However, in such a conventional flexible hose, when the monofilament is formed of a synthetic resin having poor adhesion to the resin for forming the inner tube and the outer tube, the monofilament is not formed. Although the interface where the inner tube and the outer tube contact each other without interposition is partially adhered, the interface where the inner tube and the outer tube contact each other across the monofilament is not adhered to the entire surface because the three members are not adhered. The bond strength between the tube and the outer tube has been reduced. As a result, when such a conventional flexible hose is used in a state where it expands with an increase in pressure in the tube, the monofilament enters the inner tube side, and a so-called thread drop-out phenomenon occurs, and the original There is a problem that it cannot return to the position. Conversely, when used as a vacuum hose, there is a problem that the inner tube is turned up with an increase in suction force in the tube, peels off from the outer tube, and blocks the inside of the tube.

An object of the present invention is to improve the adhesive strength between the inner tube and the outer tube regardless of the material of the monofilament. The invention described in claim 2 aims at increasing the strength of the entire hose in addition to the object of the invention described in claim 1. The third aspect of the present invention has the object of further improving the adhesive strength between the monofilament and the inner tube in addition to the object of the first or second aspect of the present invention.

[0005]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, the surface of the monofilament is made of a synthetic resin having good adhesion to the resin of the inner tube and the outer tube. The coating is performed, and the coating layer is brought into contact with the inner tube and the outer tube. According to a second aspect of the present invention, in addition to the configuration of the first aspect of the present invention, the monofilament is formed of a lightweight material, and a harder and higher-strength material is used for the coating layer. . The invention described in claim 3 is the invention according to claim 1.
Alternatively, the invention according to the second aspect is characterized in that a bottom surface of the monofilament facing the inner tube is formed flat along the outer peripheral surface of the inner tube.

[0006]

According to the first aspect of the present invention, the surface of the monofilament is coated with a synthetic resin having good adhesiveness to the resin of the inner tube and the outer tube, and the coating layer is brought into contact with the inner tube and the outer tube to form the monofilament. The surface of the monofilament is bonded to the inner tube and the outer tube via the coating layer. According to a second aspect of the present invention, there is provided
The monofilament was molded from a lightweight material, and a configuration using a harder and higher-strength material for the coating layer was added, so the surface of the monofilament made of a lightweight material was coated with a synthetic resin of a harder and higher-strength material. By doing so, the rigidity of the entire monofilament is improved. According to the third aspect of the present invention, a structure in which the bottom surface of the monofilament facing the inner tube is formed flat along the outer peripheral surface of the inner tube is added to the structure of the first or second embodiment. The bottom surface comes into surface contact with the outer peripheral surface of the inner tube, so that the adhesion area between the bottom surface of the monofilament and the outer peripheral surface of the inner tube increases through the coating layer, and the non-contact between the monofilament and the outer peripheral surface of the inner tube increases. Prevent the generation of an adhesive gap.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, as shown in FIG. 1, a monofilament 3 having a circular cross section is wound between an inner tube 1 and an outer tube 2 made of resin.

The inner tube 1 and the outer tube 2 are, for example,
It is made of a thermoplastic resin having flexibility, such as a soft vinyl chloride resin, similarly to that described in JP-A-3-46783. Further, the inner tube 1 is continuously manufactured by extruding a thermoplastic resin at a constant speed from an extruder. Then, by rotating the drum along the outer peripheral surface 1a of the inner tube 1, a monofilament 3, which will be described later, is spirally wound. Coated.

The monofilament 3 is obtained mainly by stretching an olefin-based resin such as polypropylene or polyethylene, or is obtained, for example, from JP-B-63-46783.
Thermoplastic resin, polyester resin,
Obtained by stretching nylon resin.

The surface of the monofilament 3 is
The inner tube 1 and the outer tube 2 are coated with a soft synthetic resin having good adhesion to the resin, and the coating layer 3 a is brought into contact with the inner tube 1 and the outer tube 2.

More specifically, the core portion of the monofilament 3 is formed of a light material having a low specific gravity, such as polypropylene, and the coating layer 3a is formed of, for example, P
It is preferable to use a synthetic resin material such as ET (polyethylene terephthalate) or PVC (polyvinyl chloride) which is harder than the core and has high strength and high rigidity. When a harder, higher-strength, higher-rigidity synthetic resin material is used for the coating layer 3a on the surface of the monofilament 3 made of such a lightweight material, the rigidity of the entire monofilament 3 is improved, so that the entire hose 3 is improved. Increase strength. If an inexpensive material is used for the monofilament 3 having a large amount of material and an expensive material is used for the coating layer 3a having a small amount of material, there is an advantage that the cost can be reduced.

FIG. 2 and FIG. 3 show another embodiment of the present invention. In this embodiment, the monofilament 3 having a circular cross section is used instead of the monofilament 3 having a circular cross section. The configuration in which 3b is formed flat along the outer peripheral surface 1a of the inner tube 1 is different from the embodiment shown in FIG. 1, and other configurations are the same as those in the embodiment shown in FIG.

The monofilament 3 shown in FIG.
Only b is an example in which a flat cross section is formed in a substantially semicircular or substantially semicylindrical shape, and the monofilament 3 shown in FIG. 3 is an example in which a cross section is formed in a triangular shape.

2 and 3, the monofilament 3 is spirally wound along the outer peripheral surface 1a of the inner tube 1 with its bottom surface 3b facing the outer peripheral surface 1a. The adhesion area between the bottom surface 3b of the monofilament 3 and the outer peripheral surface 1a of the inner tube 1 increases through the coating layer 3a, and when the outer tube 2 is externally covered from above, the outer peripheral surface 1a of the inner tube 1 The generation of a non-adhesive gap between the monofilament 3 and the monofilament 3 can be completely prevented. As a result, there is an advantage that the adhesive strength between the monofilament 3 and the inner tube 1 can be further improved as compared with the embodiment shown in FIG.

In the embodiment described above, the monofilament 3
FIG. 2 shows an example in which the bottom surface 3b of the inner tube 1 is formed flat along the outer peripheral surface 1a of the inner tube 1 and has a substantially semicircular or semicylindrical cross section, and FIG. 3 shows an example in which the cross section is triangular. However, the present invention is not limited to this, and may be, for example, a quadrangular or polygonal cross section.

[0016]

As described above, according to the first aspect of the present invention, the surface of the monofilament is coated with a synthetic resin having good adhesion to the resin of the inner tube and the outer tube. By contacting the inner tube and the outer tube, the surface of the monofilament is adhered to the inner tube and the outer tube via the coating layer, so that the adhesive strength between the inner tube and the outer tube can be improved regardless of the material of the monofilament. . Therefore, even if a monofilament made of a synthetic resin having poor adhesion to the inner tube and the outer tube is used, the monofilament is used even in a situation where the inner tube and the outer tube are expanded and the adhesive strength of the inner tube and the outer tube is not reduced. It is possible to prevent the user from entering the inner tube side and not returning to the original position. Even if it is used as a vacuum hose, it is possible to prevent the inner tube from being peeled off from the outer tube due to an increase in the suction force in the tube, thereby preventing the inside of the tube from being closed.

According to a second aspect of the present invention, in addition to the effect of the first aspect, the surface of the monofilament made of a lightweight material is coated with a synthetic resin of a harder and higher-strength material, thereby improving the rigidity of the entire monofilament. , The strength of the entire hose can be increased.

According to a third aspect of the present invention, in addition to the effects of the first or second aspect, the flat bottom surface of the monofilament comes into surface contact with the outer peripheral surface of the inner tube, so that the bottom surface of the monofilament contacts the bottom surface of the monofilament via the coating layer. As the adhesion area with the outer peripheral surface of the inner tube increases, and the occurrence of a non-adhesive gap between the monofilament and the outer peripheral surface of the inner tube is prevented,
The adhesive strength between the monofilament and the inner tube can be further improved.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of a flexible hose showing one embodiment of the present invention, in which a main part is partially enlarged.

FIG. 2 is a partially cutaway front view of a flexible hose showing another embodiment of the present invention, in which a main part is partially enlarged.

FIG. 3 is a partially cutaway front view of a flexible hose showing another embodiment of the present invention, in which a main part is partially enlarged.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Inner tube 2 Outer tube 3 Monofilament 3a Coating layer 3b Bottom

Claims (3)

[Claims] 1. A flexible hose in which a resin monofilament (3) formed in a coil spring shape is wound between a resin inner pipe (1) and an outer pipe (2). The surface of (3) is coated with a synthetic resin having good adhesion to the resin of the inner tube (1) and the outer tube (2), and this coating layer (3a) is applied to the inner tube (1) and the outer tube (2). A flexible hose contacted. 2. A flexible hose according to claim 1, wherein said monofilament (3) is formed of a lightweight material, and a harder and stronger material is used for the coating layer (3a). 3. The bottom surface (3b) of the monofilament (3) facing the inner tube (1) is connected to the outer peripheral surface (1) of the inner tube (1).
3. The flexible hose according to claim 1, wherein the flexible hose is formed flat along a).