JP2016061434A - Synthetic resin hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible synthetic resin hose by improving flexibility of a hose having a double wall.SOLUTION: A synthetic resin hose 1 has: an inner wall 11 and an outer wall 13 formed into a cylinder by synthetic resin; and a spiral reinforcement body 12 made of synthetic resin which is arranged between the inner wall 11 and the outer wall 13 and integrated. By the inner wall 11, the outer wall 13, and the reinforcement body 12, a hollow spiral space is formed. In the synthetic resin hose 1, the outer wall 13 is curved and swollen toward an outside of the hose between adjacent reinforcement bodies 12, 12; the inner wall 11 is curved and swollen toward an inside of the hose between the adjacent reinforcement bodies 12, 12.SELECTED DRAWING: Figure 1

Description

The present invention relates to a synthetic resin hose. In particular, the present invention relates to a synthetic resin hose having a double wall.

Some synthetic resin hoses are used as underground pipes, water conduits such as rainwater, and sewage pipes. In these hoses, in order to give the hose moderate flexibility, heat insulation, etc., the hose wall is formed into a double wall structure with a soft resin, and a helical reinforcement body made of a hard resin between the double hose walls. May be used.

For example, in Patent Document 1, as shown in FIG. 3, a hollow reinforcing core wire 92 made of a hard synthetic resin having a circular cross section is spirally wound on an inner tube 91 made of a soft synthetic resin. A synthetic resin hose 9 in which an outer tube 93 made of a soft synthetic resin is integrally provided on the hollow reinforcing core wire 92 is disclosed. The hollow reinforcing core wire 92 keeps the hose in an annular shape in cross section. It is disclosed that the spiral space formed by the pipe 91, the outer pipe 93, and the hollow reinforcing core wire 92 is an air layer that improves the heat insulation of the hose.

JP 2008-106879 A

In the synthetic resin hose 9 described in the above-mentioned patent document, the inner pipe 91 is formed as a substantially cylindrical pipe whose cross section is a straight line parallel to the hose axis. This is because such an inner tube is naturally formed when the hose is manufactured by a spiral forming method using a known hose forming shaft.

However, when the inner pipe 91 is formed in a linear cross section parallel to the hose axis, the inner pipe 91 is not easily deformed. That is, while the force acting on the hose wall is small, the inner tube having a linear cross section resists bending and contraction without causing much deformation in the hose axial direction. However, when the force acting on the hose wall is increased, the inner tube is deformed so as to buckle between the reinforcing bodies, and the deformed portion is easily bent. Therefore, the synthetic resin hose 9 is a hose that is difficult to bend while the bending force or moment is small, but when the bending force or moment is large, the portion where the hose is located is bent, and only that portion is bent. Thus, the synthetic resin hose 9 becomes a hose lacking in flexibility. If the hose lacks flexibility, it will be difficult to smoothly curve the hose and pipe it, and the flow will become worse at the part where the hose is bent.
An object of the present invention is to provide a flexible synthetic resin hose that improves the flexibility of a hose having a double wall.

As a result of intensive studies, the inventor has swelled the inner wall and the outer wall constituting the double wall of the hose between the reinforcing bodies adjacent to each other in the axial direction of the hose so that the outer wall is curved toward the outside of the hose. It has been found that the flexibility of the hose can be improved by curving toward the inside of the hose, and the present invention has been completed.

The present invention has an inner wall and an outer wall formed in a cylindrical shape by a synthetic resin, and a spiral reinforcing body made of a synthetic resin that is disposed and integrated between the inner wall and the outer wall, and the inner wall, the outer wall, and the reinforcing body A hose made of a synthetic resin in which a hollow spiral space is formed, and the outer wall is curved and bulged toward the outside of the hose between the reinforcing bodies adjacent to each other, and the inner walls are reinforced adjacent to each other It is a synthetic resin hose which curves and bulges between the bodies toward the inner side of the hose (first invention).

In the present invention, it is preferable that the spiral space is not filled with other members (second invention).

Moreover, this invention is a method of manufacturing the synthetic resin hose according to claim 1, wherein a tape-shaped synthetic resin strip having a predetermined width is wound in a spiral shape, and both side edges of the strip are joined together. A process of forming a cylindrical inner wall by integrating, a spiral synthetic resin strip having a predetermined cross-sectional shape is spirally wound on the outer periphery of the inner wall, and integrated with the outer periphery of the inner wall to form a spiral reinforcement body And a step of winding a tape-shaped synthetic resin strip having a predetermined width around the outer periphery of the spiral reinforcing body, forming a cylindrical outer wall by integrating both side edges of the strip, and spiraling The process of integrating the outer wall with the outer periphery of the reinforcement body forms a synthetic resin hose in which a hollow spiral space is formed by the inner wall, the outer wall, and the reinforcement body, and the inner wall and the outer wall being formed can still be plastically deformed. While in a normal state, pressure is applied in the formed spiral space. It was added, the outer wall to the hose outside, a method for producing a synthetic resin hose which bulging plastically deforming the inner wall hose inside (third invention).

Further, the present invention is a method for producing the synthetic resin hose according to claim 1, wherein a tape-shaped synthetic resin strip having a width of at least twice the pitch of the hose to be formed is spirally wound. Turn the tape-shaped synthetic resin strip following the previously wound portion so that it overlaps and winds, while the tape-shaped synthetic resin strip is overlapped, A hollow spiral space was formed by the inner wall, the outer wall, and the reinforcing body by the step of forming the inner wall and the outer wall from the tape-shaped synthetic resin strip, sandwiching the resin strip, and forming the reinforcing body from the resin strip. While forming the synthetic resin hose, the inner wall and the outer wall being formed are still in a state where they can be plastically deformed, and pressure is applied to the formed spiral space so that the outer wall is outside the hose and the inner wall is the hose. Inward bulging plastic deformation A method for producing a synthetic resin hose which (fourth invention).

According to the synthetic resin hose of the present invention (first invention), the synthetic resin hose becomes a pliable hose. Furthermore, if the spiral space is not filled with other members as in the second aspect of the invention, the hose becomes more supple, and the spiral space is connected with a pressure transmission path and other fluids. The usefulness of the hose can be enhanced, for example, it can be used as a conduit to flow through. Moreover, according to the hose manufacturing method of 3rd invention or 4th invention, such a flexible hose can be manufactured efficiently.

It is a partial cross section figure which shows the structure of the synthetic resin hoses of this invention. It is a schematic diagram which shows the manufacturing method of the synthetic resin hoses of this invention. It is sectional drawing which shows the structural example of the pipe wall of the conventional synthetic resin hoses. It is a schematic diagram which shows the other manufacturing method of the synthetic resin hoses of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. A synthetic resin hose 1 according to the present invention described below is a synthetic resin hose used as a rainwater conduit for road bridges, for example. The present invention is not limited to the individual embodiments shown below, and can be carried out by changing the form.

As shown in FIG. 1, the synthetic resin hose 1 is composed of a hard synthetic resin (for example, a soft vinyl chloride resin) and a hard wall that is helically disposed between the inner wall 11 and the outer wall 13 and between the inner wall 11 and the outer wall 13. It is comprised with the reinforcement body 12 made from a synthetic resin (for example, hard vinyl chloride resin etc.). Each of the inner wall 11 and the outer wall 13 is formed in a cylindrical shape, and functions to block movement of rainwater and the like inside and outside the hose. The inner wall 11 is arranged on the inner side of the hose than the outer wall 13, and the inner wall 11 and the outer wall 13 make the hose a double wall structure.
The reinforcing body 12 is formed by spirally winding a string-like resin member having a predetermined cross-sectional shape. In this embodiment, the cross-sectional shape of the reinforcing body 12 is a gate shape opened toward the inside of the hose. The outer peripheral surface of the reinforcing body 12 is joined and integrated with the inner peripheral surface of the hose outer wall 13, and the inner peripheral surface of the reinforcing body 12 is joined and integrated with the outer peripheral surface of the hose inner wall 11. In this embodiment, the three are welded and integrated with each other.

The reinforcing body 12 maintains the cylindrical shape of the hose. Since the reinforcing body 12 is helical, the hose 1 is allowed to expand and contract and bend. The inner wall 11 and the outer wall 13 are made of a synthetic resin that is relatively softer and more flexible than the reinforcing body 12. The inner wall 11 and the outer wall 13 can expand and contract, and the synthetic resin hose 1 expands and contracts when the inner wall 11 and the outer wall 13 expand and contract in the hose axial direction.

A predetermined gap is provided between the inner wall 11 and the outer wall 13. The gap is partitioned in the direction of the hose central axis L by a spiral reinforcing body 12, and a hollow spiral space S is formed by the inner wall 11, the outer wall 13, and the reinforcing body 12. In the present embodiment, the spiral space S is not filled with other members, for example, a heat insulating material such as a filler or a foamed resin, and the spiral space S contains atmospheric pressure air. .

Between the reinforcing bodies 12 adjacent to each other, that is, between the portions where the spirally wound reinforcing bodies 12 are adjacent to each other, the outer wall 13 is curved and bulges toward the outside of the hose. That is, the cross section of the outer wall 13 between the reinforcing bodies 12 is formed in an arc shape that is convex toward the outside of the hose. Further, between the reinforcing bodies 12 adjacent to each other, that is, between the portions where the spirally wound reinforcing bodies 12 are adjacent to each other, the inner wall 11 is curved and bulges toward the inside of the hose. That is, the cross section of the inner wall 11 between the reinforcing bodies 12 is formed in an arc shape that is convex toward the inside of the hose.

As the soft synthetic resin material constituting the inner wall 11 and the outer wall 13, a synthetic resin material that is softer than the reinforcing body, for example, a duro A hardness of 45 to 85 degrees can be used. For example, an ethylene vinyl acetate resin ( EVA, thermoplastic vinyl chloride resin (PVC), low density polyethylene resin (LDPE), thermoplastic urethane-based elastomer (TPU), and other thermoplastic soft resin materials can be preferably used. In this embodiment, the inner wall 11 and the outer wall 13 are formed of a soft vinyl chloride resin.

As the hard synthetic resin material constituting the reinforcing body 12, a synthetic resin material which is harder than the inner wall and the outer wall, for example, having a duro D hardness of about 60 to 90 degrees can be used. For example, a polypropylene resin or a high density polyethylene can be used. Rigid thermoplastic resins such as resins, polyamide resins and rigid vinyl chloride resins can be preferably used. In the present embodiment, the reinforcing body 12 is formed of a hard vinyl chloride resin.
Resin materials constituting the inner wall 11, the outer wall 13, and the reinforcing body 12 are selected so that they can be bonded to each other. In particular, it is preferable to select materials that can be welded to each other.

A method for manufacturing the synthetic resin hose 1 will be described. The synthetic resin hose 1 can be manufactured by a so-called spiral molding method in which a hose raw material is supplied to a hose molding shaft and spirally integrated.

First, a first resin strip T1 obtained by extruding a resin material (soft vinyl chloride resin) to be an inner wall in a semi-molten state in a tape shape having a width larger than the feed pitch of the hose molding shaft, Supplied to the hose forming shaft SFT that is rotating and feeding. The first resin strip T1 is spirally wound on the hose forming shaft, and is integrated so that adjacent side edges overlap each other, thereby forming a cylindrical inner wall.

Subsequently, a resin string (resin strip) S1 is formed by extruding a resin material (hard vinyl chloride resin) to be a reinforcing body into a string having a predetermined cross-sectional shape (gate shape) in a semi-molten state. Supplied to the outer peripheral surface of the inner wall. The resin string S1 is spirally wound while being welded to the outer periphery of the inner wall to form a reinforcing body.

Subsequently, a second resin strip T2 obtained by extruding a resin material (soft vinyl chloride resin) to be an outer wall into a tape shape having a width larger than the feed pitch of the hose molding shaft in a semi-molten state, It supplies to the outer periphery of the formed reinforcement body. The second resin strip T2 is spirally wound by the rotational feeding operation of the hose forming shaft, and is integrated so that adjacent side edges overlap with each other to form a cylindrical outer wall, while the outer periphery of the reinforcement body. Welded to the surface

Subsequently, a predetermined bulging shape is given to the inner wall and the outer wall. When the second resin strip T2 is wound around the outer periphery of the reinforcement body, a spiral space S is formed. From the portion where the second resin strip T2 is wound around the reinforcement body, the spiral space S is formed. A fluid is supplied toward S to increase the pressure in the spiral space. The fluid may be air or a liquid such as water. In order to effectively increase the pressure, it is preferable to close the spiral space S or reduce the opening of the spiral space S at the tip of the molded hose 1.

When pressure is applied to the inside of the spiral space S, the inner wall curves and bulges toward the inside of the hose, the outer wall curves and bulges toward the outside of the hose, and both of them deform plastically, and the inner wall as shown in FIG. A synthetic resin hose having the form of the outer wall is obtained.

Here, on the downstream side (right side in FIG. 2) from the position where the fluid is supplied and pressure is applied, while the inner wall and the outer wall that are being formed are still in a state where they can be plastically deformed, pressure is applied and both are plasticized. It is important to deform. Usually, pressure is applied immediately after the outer wall is wound in a semi-molten state, so that bulging deformation easily occurs toward the outside. On the other hand, in order to bulge and deform the inner wall inward, the inner wall being formed by the first resin strip is allowed to pass through the terminal SFTE of the hose forming shaft while still maintaining a plastically deformable state. Thus, at a portion ahead of the terminal SFTE (on the right side in FIG. 2), the pressure is applied to the space S so as to bulge and deform inside the hose. For example, it is preferable that the temperature of the inner wall is not lowered by the hose forming shaft so much by keeping and heating the hose forming shaft SFT.

The inner wall and the outer wall of the hose are cooled by the cooling device C at a position after the inner wall and the outer wall are swelled by pressurization, and the form of the hose is fixed. Water or air can be used for cooling. FIG. 2 shows a cooling device that cools from the outside of the hose. However, if cooling water or cooling air is supplied from the hose forming shaft, the inner wall can be cooled from the inner peripheral side of the hose. Or you may make it cool using the fluid for pressurizing the space S. FIG.
Through the above steps, the synthetic resin hose of this embodiment can be continuously manufactured with an indefinite length.

In the above manufacturing method, an example of a manufacturing method in which the inner wall and the outer wall and the reinforcing body are integrated by welding has been shown. However, the integration may be performed using an adhesive, In the case of integration by bonding, an adhesive may be appropriately applied at the stage of winding around the hose forming shaft.

The effects of the synthetic resin hose of the present invention will be described.
The synthetic resin hose 1 of the present invention is a flexible hose as compared with the prior art.
In the case of a synthetic resin hose having a conventional structure as shown in FIG. 3, the inner wall 91 is formed to have a linear cross section parallel to the central axis of the hose. It was easy to become resistance. That is, the inner wall 91 is formed in a cylinder having a linear cross section, and is not so deformed to some extent when a contracting force is applied, so that the inner wall between the reinforcing bodies buckles when the contracting force increases. In many cases, the inner wall contracts at a stretch. Therefore, while the synthetic resin hose 9 having the conventional structure is slightly difficult to bend, if one portion is bent (when the inner wall buckles and deforms at that portion), only that portion is easily bent, and the entire hose is It was difficult to pipe in a gently bent form. That is, the hose having the conventional structure lacks flexibility.

On the other hand, in the synthetic resin hose 1 of the present invention, the outer wall is curved toward the outer side of the hose and the inner wall is curved toward the inner side of the hose between the reinforcing bodies adjacent to each other. Even if the contraction force acting on the hose is small, it is easily deformed with respect to the force and deforms according to the contraction force. Therefore, unlike a synthetic resin hose having a conventional structure, the hose wall is not deformed so as to be suddenly buckled, and the hose is easily bent in a mode in which the hose is gently bent.

From the viewpoint of improving the flexibility of the hose, it is preferable that the inner wall and the outer wall bend and bulge more than the wall thickness of the inner wall and the outer wall, more preferably more than twice the wall thickness.

Further, in the synthetic resin hose 1 of the present invention, the fact that the outer wall bulges toward the hose outer side and the inner wall bulges toward the hose inner side also contributes to improvement of the flexibility of the hose. If the outer wall bulges toward the inner side of the hose or the inner wall bulges toward the outer side of the hose, the inner wall and the outer wall enter into the spiral space S when contracted and interfere with each other. Smooth deformation may be impaired.

Further, the fact that the outer wall bulges toward the outer side of the hose and the inner wall bulges toward the inner side of the hose contributes to an improvement in fitting property of the hose 1 to the joint member. When the joint member is fitted to the outer periphery of the synthetic resin hose 1, the outer wall portion bulged toward the outer side of the hose comes to fit with the joint member while deforming linearly. It becomes easy to insert and fix the joint member and the hose 1. Moreover, since the outer peripheral surface of the outer wall is biased and comes into close contact with the inner peripheral surface of the joint member, the airtightness and liquid tightness between the synthetic resin hose 1 and the joint member are impaired at the outer wall portion. Is suppressed. Similarly, when the joint member is fitted to the inner periphery of the synthetic resin hose 1, the portion of the inner wall bulged toward the inner side of the hose is linearly deformed so as to be fitted with the joint member. Therefore, it is easy to perform the insertion / fixing operation, and the airtightness and liquid tightness are prevented from being impaired at the inner wall portion.

Furthermore, in the synthetic resin hose 1 of the present invention, when the spiral space S is not filled with other members, the deformation of the inner wall and the outer wall is not hindered by the other members, so the hose is more supple. become. Moreover, if the spiral space S is not filled with other members, this space can be utilized for the following uses, and the usefulness of the hose is enhanced. The spiral space S that is not filled with other members can be used as, for example, a pressure transmission path, a conduit for allowing a gas or liquid other than the substance flowing through the hose body to flow, and the like.

Further, according to the above-described hose manufacturing method, if a synthetic resin hose having a hollow spiral space formed by the inner wall, the outer wall, and the reinforcing body is formed, the inner wall and the outer wall that are being formed can still be plastically deformed. In the meantime, pressure was applied to the formed spiral space to plastically deform the outer wall to the outside of the hose and the inner wall to bulge to the inside of the hose. It is possible to manufacture efficiently using manufacturing equipment.

The present invention is not limited to the above embodiment, and can be implemented with various modifications. For example, the use of the hose is not limited to rainwater conduits for road bridges, but can also be used for piping for flowing sewage and drainage, underground pipes for cable protection, and other uses.

In addition, the cross-sectional shape of the reinforcing body may be changed as appropriate, such as a solid rectangular shape, a hollow circular shape, or a gate shape that opens outward.

In the description of the above embodiment, the synthetic resin hose and its manufacturing method in which the inner wall 11 is formed by the first resin strip T1 and the outer wall 13 is formed by the second resin strip T2 have been described.
The formation of the inner wall and the outer wall is not limited to the manufacturing method of the above-described embodiment, and may be performed by another manufacturing method.

For example, a wide tape-shaped synthetic resin strip T3 having a width more than twice the feed pitch of the hose forming shaft (that is, the pitch of the hose to be formed) is spirally wound and wound in advance. A string-like resin that will later become a reinforcing body 12 between the overlapping tape-shaped synthetic resin strips T3 while winding the tape-shaped synthetic resin strip T3 that overlaps the portion. The inner wall 11 and the outer wall 13 are formed by the tape-shaped synthetic resin strip T3 so as to sandwich the string (resin strip) S1, and the reinforcing body 12 is formed by the resin string (resin strip) S1. Also good. A schematic diagram of such a manufacturing method is shown in FIG. A cylindrical inner wall 11 is formed by a portion of the wide tape-shaped resin strip T3 located on the upstream side (left side in FIG. 4) of the hose forming shaft SFT. A cylindrical outer wall 13 is formed by a portion of the wide tape-shaped resin strip T3 located on the downstream side (right side in FIG. 4) of the hose forming shaft SFT. From the viewpoint of being able to be welded and integrated, and from the viewpoint of enabling plastic deformation described later, the tape-shaped synthetic resin strip T3 and the resin string (resin strip) S1 are made of a thermoplastic resin, both of which are hose molded in a semi-molten state It is preferably supplied to the shaft SFT and wound.

Even when the inner wall and the outer wall are formed by such a method, while the inner wall and the outer wall that are being formed are still in a state where they can be plastically deformed, pressure is applied by blowing air into the formed spiral space. In addition, since the outer wall is plastically deformed so that the inner wall bulges inside the hose, the synthetic resin hose 1 can be efficiently manufactured by utilizing existing manufacturing equipment. .

The synthetic resin hose of the present invention may further include other layers, for example, a heat insulating layer, an external protective layer, and the like. When these other layers are provided, it is preferable to provide a gap between the other layers and the inner wall or the outer wall or to make the other layer a flexible layer so as not to inhibit the deformation of the inner wall and the outer wall.

The synthetic resin hose of the present invention can be suitably used, for example, as a water pipe for rainwater or the like, can be easily manufactured, and has high industrial utility value.

DESCRIPTION OF SYMBOLS 1 Synthetic resin hose 11 Inner wall 12 Reinforcement body 13 Outer wall SFT Hose molding axis | shaft T1 1st resin strip T2 2nd resin strip S1 Resin strip C used as a reinforcement body Cooling device

Claims (4)

It has an inner wall and an outer wall formed in a cylindrical shape by a synthetic resin, and a spiral reinforcement body made of synthetic resin disposed between and integrated between the inner wall and the outer wall, and a hollow spiral formed by the inner wall, the outer wall, and the reinforcement body A synthetic resin hose in which a space is formed,
The outer wall is curved and bulged toward the outside of the hose between the reinforcing bodies adjacent to each other,
A synthetic resin hose whose inner wall is curved and bulges toward the inside of the hose between reinforcing bodies adjacent to each other. The synthetic resin hose according to claim 1, wherein the spiral space is not filled with another member. A method for producing the synthetic resin hose according to claim 1,
A step of winding a tape-shaped synthetic resin strip having a predetermined width into a spiral shape, and integrating both side edges of the strip to form a cylindrical inner wall;
A step of spirally winding a string-like synthetic resin strip having a predetermined cross-sectional shape on the outer periphery of the inner wall, and integrating the outer periphery of the inner wall to form a spiral reinforcing body;
A tape-shaped synthetic resin strip having a predetermined width is spirally wound around the outer periphery of the spiral reinforcing body, and both side edges of the strip are integrated to form a cylindrical outer wall. By integrating the outer wall with the outer periphery,
While forming a synthetic resin hose in which a hollow spiral space is formed by an inner wall, an outer wall, and a reinforcing body,
While the inner wall and outer wall being formed are still in a state where they can be plastically deformed, a pressure is applied in the formed helical space to swell the outer wall to the outside of the hose and the inner wall to bulge plastically to the inside of the hose. A method for manufacturing a hose. A method for producing the synthetic resin hose according to claim 1,
A tape-shaped synthetic resin strip having a width more than twice the pitch of the hose to be formed is spirally wound, and the tape-shaped synthetic resin strip following the previously wound portion overlaps. While being wound, the string-like resin strip is sandwiched between the overlapping tape-shaped synthetic resin strips to form the inner and outer walls from the tape-shaped synthetic resin strip. By the process of forming the reinforcement from the band,
While forming a synthetic resin hose in which a hollow spiral space is formed by an inner wall, an outer wall, and a reinforcing body,
While the inner wall and outer wall being formed are still in a state where they can be plastically deformed, a pressure is applied in the formed helical space to swell the outer wall to the outside of the hose and the inner wall to bulge plastically to the inside of the hose. A method for manufacturing a hose.

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