JP2015102195A - Flexible hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible hose having a structure where positional deviation of an inner core and an outer core is hard to occur.SOLUTION: In a flexible hose 1 where a tube body 11 is covered on an inner core 10, and by winding an outer core 15 on the tube body 11 so as to form a double spiral structure between the outer core 15 and the inner core 10, a spiral uneven surface is incorporated in the tube body 11, the inner core 10 is molded so that its cross section has a rectangle shape with a resin material; tube body 11 is molded seamlessly with a resin material; the outer core 15 is molded with a resin material; and a restraining layer 17 is formed, which covers the outer peripheral surface of the outer core 15 so as to pressure-weld the outer peripheral surface to inside, is fused on the outer peripheral surface of the outer core 15, and suppresses expansion in the radial direction of the inner core 10.

Description

  The present invention relates to a flexible hose mainly suitable for chemical applications such as chemicals, chemicals, and solvents. More specifically, the tube main body forming the tube wall of the hose has an inner spiral core made of resin (also referred to as an inner core) and The present invention relates to a flexible hose having a structure sandwiched between outer spiral cores (also referred to as outer cores).

  A flexible hose having a structure in which a spiral core is reinforced with respect to the inner and outer surfaces of a tube main body having spiral irregularities is called, for example, a dew-line hose, and is used for various applications (for example, patents). References 1-3).

  In the flexible hose having such a structure, the inner and outer spiral cores are in contact with the concave surface of the tube body in a free state without being fixed (fused) to the tube body. Even if it is twisted or bent, the hose is flexible without breaking.

However, due to the fact that the tube main body and the spiral core are not fixed, if the hose is bent greatly, the spiral core moves over the adjacent convex surface and moves to the adjacent concave surface. May occur.
Therefore, in the conventional flexible hose, the inner spiral core is made of a material having elasticity (for example, a metal wire), and the inner spiral core always applies a force for urging the tube body, so that the position of the spiral core is shifted. Is not easy to occur.
That is, when the hose is manufactured, a tension is applied to the inner spiral core in advance so that the diameter of the spiral is reduced as compared with the free state. In this state, the tube body is covered with the inner spiral core, and the tube The outer spiral core is wound around the outside. Thereafter, by returning the inner spiral core to a free state, the inner spiral core expands in the radial direction, and the tube body is biased. In this case, in order to give tension to the inner spiral core, the inner spiral core having a desired (finite) length must be previously processed and pulled from both sides. For this reason, the production process is not a continuous production method in which the inner spiral core molding process, tube body molding process, and outer spiral core molding process are performed continuously, but in a batch production method in which production is performed for each finite length. I have to.

Utility Model Registration No. 2546519 Japanese Patent No. 3556278 Japanese Patent Laid-Open No. 11-257553

As described above, when a material such as a metal wire having elasticity is used for the inner spiral core, an urging force can be applied, so that the problem of positional deviation of the spiral core during bending can be solved.
However, depending on the use of the hose, it may not be possible to use a metal wire that can give sufficient elastic force, such as when a corrosive fluid that corrodes the metal is passed through the hose. Therefore, instead of a metal wire, a structure in which the entire hose is made of all resin using a resin spiral core is also used. The all-resin hose is not only corrosive but also excellent in terms of weight reduction. Furthermore, when a resin spiral core is used, a special cutting tool is not required and a simple tool (for example, a nipper) Etc.) is also excellent in that it can be easily cut.

  However, even if all the constituent materials are to be continuously produced as a resin, the resin inner spiral core that is continuously extruded in a semi-molten state and wound in a spiral shape is like a metal wire due to problems such as breaking. It is difficult to obtain a sufficiently large elastic force. Therefore, it is a case where it is manufactured so as to give an elastic force in the same manufacturing process as the above-described metal wire (a batch production system in which the tube body is covered with a tension reduced on the inner spiral core first). However, a large urging force could not be applied, and the problem of positional displacement of the spiral core was likely to occur.

  In addition, when manufacturing flexible hoses made of all-resin, a continuous production system is used in which the flow from the inner spiral core molding process to the tube main body molding process to the outer spiral core molding process is performed continuously. It is desirable to adopt. That is, by adopting extrusion molding, while forming the inner spiral core, the tube body is continuously molded while covering the surface of the inner spiral core, and further, the outer spiral core is continuously formed on the outer side of the tube body. Wrapping enables continuous production instead of batch production. Such continuous production also makes it possible to produce seamless tubes with no length restrictions.

  However, in the continuous production method, the forming process of the inner spiral core and the molding process of the tube body are performed continuously in a flow operation, so the tube body is covered with tension applied by pulling the inner spiral core from both ends. I can't. Therefore, the force which urges | biases a tube main body to an inner side spiral core was not able to be provided. Therefore, it has been difficult to manufacture an all-resin flexible hose that is unlikely to cause a positional shift of the spiral core by a continuous production method.

  Therefore, the present invention provides a flexible structure having a structure in which the problem of positional displacement of the spiral core with respect to the tube main body is less likely to occur even when the inner spiral core and the outer spiral core are all resin-made flexible hoses. The purpose is to provide a hose.

  In particular, it is a hose with a structure in which the inner spiral core and the tube main body cannot be biased against the tube main body, such as a flexible hose by continuous production in which the inner spiral core and the tube main body are simultaneously formed in a flow operation. Even if it exists, it aims at providing the flexible hose of the structure which does not produce the problem of the position shift of the spiral core at the time of curvature.

  The flexible hose of the present invention, which has been made to solve the above problems, covers the tube main body 11 on the inner core 10 formed in a spiral shape, and further the outer core 15 formed in a spiral shape on the tube main body 11. , 25 are wound around the inner core 10 so as to form a double spiral structure, and the tube body 11 is formed with a helical irregular surface, and the inner core 10 is made of resin. The tube body 11 is seamlessly formed of a resin material, the outer cores 15 and 25 are formed of a resin material, and the outer cores 15 and 25 are disposed outside the outer cores 15 and 25. The outer peripheral surfaces of the outer cores 15 and 25 are covered so as to be in pressure contact with each other and are fused to the outer peripheral surfaces of the outer cores 15 and 25 to suppress the bulges of the outer cores 15 and 25 and the inner core 10 in the radial direction. Transfer of cores 15 and 25 Are as constraining layers 16, 17, 18 to limit the width is formed.

According to the present invention, the inner core is molded using a resin material without applying an elastic force that presses the tube body in the radial direction. The inner core and the tube main body are covered in a free state without being fixed. The tube main body and the outer core are also wound so as to form a double spiral structure with the inner core from above the tube main body in a free state without being fixed.
Then, a constraining layer is provided outside the outer core so as to cover the outer core and the tube body, and the constraining layer presses the outer peripheral surface of the outer core inward. As a result, the constraining layer presses the tube body inward via the outer core, so that the inner core is pressed by the tube body even if the inner core itself does not have an elastic force to urge the tube body. Therefore, there is no inconvenience that the position of the tube body is shifted over the uneven surface.
As for the outer core, since the constraining layer is fused to the outer peripheral surface of the outer core and only one outer core cannot be displaced alone, there is no problem of displacement.

  According to the present invention, since the tube main body is pressed from the outside via the outer core by the constraining layer, even if a resin inner core with insufficient elasticity is used, there is a problem of positional deviation of the spiral core. Occurrence can be suppressed. Since the constraining layer is also fused to the outer peripheral surface of the outer core made of resin, positional displacement does not occur unless the entire outer core is moved all at once, so that the problem of positional displacement can be suppressed. Also, the cross-sectional shape of the inner core is rectangular, and when the hose is bent, even if the inner core and the tube body are not biased and are in a free state, a positional shift occurs. Hateful.

In the above invention, the constraining layer may be formed of a woven yarn layer and an elastomer layer that sandwiches the woven yarn layer from the front and back sides and gives elasticity.
Here, the woven yarn layer is preferably a layer woven in a lattice shape with stretched yarn. Specifically, a material in which polyester yarn is woven is preferable as a suitable yarn material. The woven yarn layer also includes a layer woven in a cloth shape (woven yarn layer with finely woven texture). In addition, the yarn itself is difficult to stretch by making it a layer woven with stretched yarn material, but by making it a woven yarn, the layer itself is a layer that can be easily deformed by following bending and twisting. .
And by sandwiching the front and back of the woven yarn layer with an elastic elastomer layer, it can be fused to the outer core together with the woven yarn layer, not only can increase the force urged by the elastomer layer, It is possible to prevent deterioration of the yarn layer due to repeated repetition of the state in which the yarn layer directly rubs against the outer peripheral surface of the tube main body (position just above the inner core).

In the above invention, a gap for enabling bending is provided between the outer core and the inner core adjacent to each other, and the gap is in contact with the tube body in the most curved state. It may be set.
In the curved state, the inner core and the outer core are brought into contact with each other with the tube body interposed therebetween, so that the inner core and the outer core that cause the positional deviation of the spiral core can be prevented from being twisted and rotated. Misalignment can be suppressed.

In the above invention, a yarn distribution layer that tightens the outer region of the outer core and the outer region of the inner core as a whole may be formed outside the constraining layer.
Although the force applied to the constraining layer in the curved state varies between the outer region of the outer core and the outer region of the inner core, the force can be made uniform. The yarn distribution layer is also preferably a yarn that does not easily stretch, and specifically, a polyester yarn is suitable in the same manner as the woven yarn layer.

It is an external view of the flexible hose which shows one Embodiment of this invention. It is the perspective view which decomposed | disassembled and showed the cross section of the flexible hose of FIG. It is a schematic diagram which shows the state which curved the hose of FIG. It is the perspective view which exploded and showed the section of the flexible hose which is a modification.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing the appearance of a flexible hose according to an embodiment of the present invention, and FIG. 2 is a perspective view showing an exploded partial cross section thereof.
The flexible hose 1 includes an inner core 10, a tube body 11, an outer core 15, and a constraining layer 16 as basic components, and further, a yarn distribution layer 20, an outer winding layer 21, and a protective layer 22 are provided on the outer side. .

  The inner core 10 is formed of a hard resin material (for example, PP (polypropylene resin)), and is continuously formed by being wound around a mandrel serving as a mold and formed into a spiral shape during extrusion molding. It is. The cross section of the inner core 10 is a square, more specifically, a trapezoid in which the inner surface (lower side) side of the hose is longer than the outer surface (upper side) side in order to expand the bending angle when bending.

The tube body 11 is formed as a laminate of resin film layers 12, 13 and 14. The thickness of the laminated body is much thinner than the thickness of the inner core 10 (and the outer core 15). The material and the number of layers of the film layer are changed according to the usage application of the hose. For example, by using a three-layer structure of fluororesin, PP, and fluororesin, a hose having chemical resistance and gas barrier properties can be obtained.
For example, by adopting extrusion molding using a rotating die, the tube main body 11 is formed so that each layer is sequentially formed so as to cover the outer side of the inner core 10 that is previously molded. The laminated body formed at this time is still cylindrical and not in a spiral shape.

The outer core 15 is formed by molding a hard resin material (for example, PE (polyethylene resin)), and is spirally wound by extrusion so as to form a double spiral structure with respect to the inner core 10 covered with the laminate. It is formed by walking.
As a result, the laminated body (resin film layers 12, 13, 14) sandwiched between the inner core 10 and the outer core 15 is formed with uneven surfaces along the inner core 10 and the outer core 15. A tube body 11 having a concavo-convex shape is formed. And the tube main body 11 on the inner core 10 and the outer core 15 on the tube main body 11 can be continuously processed by a flow operation, and can be produced as a seamless hose having a desired length.

  The inner core 10, the tube main body 11, and the outer core 15 are not fixed to each other, but the cross section of the inner core 10 is rectangular, and the tube main body 11 (laminated body) is thin, and the inner core 10 and the outer core 15 The length (height) in the radial direction is the same, or the inner core 10 is slightly shorter than the outer core 15. Therefore, in order for the inner core 10 to move over the adjacent outer core 15 when it is bent, it has a structure that has to climb over the same height as the inner core 10, so it is very resistant. The shape is so large that misalignment is unlikely to occur.

Moreover, since the outer core 15 and the inner core 10 have the same height and the tube main body 11 is thin, the outer peripheral surface side of the outer core 15 comes into contact with the constraining layer 16 in a free state. The cross section of the outer core 15 is elliptical (circular) in this embodiment.
The lateral width of the outer core 15 and the lateral width of the inner core 10 are determined in relation to the pitch of the irregularities of the tube body 11 (that is, the pitch of the inner core 10). Specifically, the gap (play) necessary to be in a curved state is ensured between the inner core 10 and the tube main body 11 and between the tube main body 11 and the outer core 15 and is most flexible. In such a state, the left and right inner cores 10 (outer core 15) are sandwiched and fixed by the outer core 15 (inner core 10) between them, so that the inner core 10 (outer core 15) extends in the vertical and horizontal directions. The gap is set so as not to cause misalignment (see FIGS. 3A and 3B).

A constraining layer 16 is coated on the outer side of the outer core 15 so as to cover the outer core 15 and the tube body 11. The constraining layer 16 includes a weaving yarn layer 18 in which stretched polyester yarns are woven into a lattice shape to give stretchability, and elastomer layers 17 and 19 (for example, sandwiching the weaving yarn layer 18 from both front and back surfaces with a stretchable material). Olefin elastomer, styrene elastomer, ethylene vinyl acetate copolymer (EVA), etc.). The constraining layer 16 covers the outer peripheral surface of the outer core 15 with a tension applied so that the outer core 15 is pressed from the outside. As a result, the outer core 15 presses the tube main body 11 inward, and the tube main body 11 presses the inner core 10. Is pressed.
The portion P of the outer peripheral surface in contact with the outer core 15 is fused to the constraining layer 16 in a tensioned state. Thus, in order to increase the distance between the outer cores 15, it is necessary to expand against the tension of the constraining layer 16, so that the distance between the outer cores 15 can be increased only slightly. That is, the length of the outer core 15 that can move in the direction of the spiral axis (lateral direction) is limited to the expandable width of the constraining layer 16, and the outer core 15 overcomes the adjacent convex surface of the tube main body 11 and has one outer core. Only 15 is prevented from being displaced.

On the outer side of the constraining layer 16, in order to improve the pressure resistance performance of the hose 1, a yarn distribution layer 20 woven with polyester yarn so as to cover the entire constraining layer 16 and an outer winding layer 21 are formed on the outer side thereof. is there. In the curved state, the force applied to the constraining layer 16 varies between the outer region of the outer core 15 and the outer region of the inner core 10, but the force can be made uniform by the presence of the yarn distribution layer 20 and the outer winding layer 21. it can. Further, when a large internal pressure is applied, the tube main body 11 can be prevented from expanding and being damaged due to the presence of these.
Furthermore, a protective layer 22 having a spiral protrusion is formed on the outer side of the outer winding layer 21. This protective layer 22 is for receiving an external impact at this protrusion, and thereby, the outer winding layer 21 and each part inside thereof are protected from the external impact.

Next, a state where the above-described flexible hose 1 is bent will be described. In general, in the flexible hose 1 in which the inner core 10 and the outer core 15 are not fixed, the spiral core is liable to be displaced in a curved state. FIG. 3 is a schematic view showing a state when the hose 1 is bent.
Fig.3 (a) is a schematic diagram of the part curved in the direction in which the adjacent inner cores 10 (outer cores 15) leave | separate (outside of a curved part).
The restraint layer 16 is more tensioned than the state in which the flexible hose 1 is free (not bent), and strongly presses the outer core 15 in the inner direction. As described above, the outer peripheral surface side of the outer core 15 is fused to the constraining layer 16. For this reason, the distance between the outer peripheral surfaces of the outer cores 15 cannot be increased against the constrained constraining layer 16, and therefore it cannot be bent by deformation that increases the distance between these parts as compared to the free state. Therefore, in order for the hose 1 to bend at this portion, the hose 1 is deformed so that the gap (play) between the outer core 15 and the inner core 10 is reduced in the vicinity of the inner peripheral surface side of the outer core 15. As the deflection increases, the inner core 10 is sandwiched between the left and right outer cores 15 (via the tube body 11), and the inner core 10 is twisted or rotated in the direction of the helical axis that triggers misalignment. It becomes difficult to occur. Furthermore, twisting and rotation are less likely to occur by making the cross-sectional shape of the inner core 10 square. In this way, the inner core 10 and the outer core 15 do not get over the convex surface by approaching and contacting the adjacent cores.

FIG. 3B is a schematic diagram of a portion curved in a direction in which adjacent inner cores 10 (outer cores 15) approach each other (inside the curved portion).
The constraining layer 16 is less tensioned than when the flexible hose 1 is free. As the flexure increases, the tension is not applied, but the outer cores 15 approach each other and the inner cores 10 approach each other. As a result, the outer core 15 and the inner core 10 are sandwiched with each other (via the left and right tube bodies 11). Accordingly, the inner core 10 and the outer core 15 are restricted from being further deformed (twisted and rotated), so that no displacement occurs. Since the outer core 15 is also sandwiched from both sides, the positional deviation is less likely to occur.

  The above is for the outer core 15, but also for the inner core 10, since the outer core 15 presses the tube main body 11 and the inner core 10 is pressed by the tube main body 11, misalignment hardly occurs. Further, since the inner core 10 is rectangular and the resistance to get over the convex surface is increased, this also prevents misalignment. Further, when the angle of bending increases in the state shown in FIG. 3B, the inner core 10 is also sandwiched by the adjacent outer cores 15 and cannot move vertically and horizontally, so that the same positional displacement as the outer core 15 occurs. Disappear.

(Other embodiments)
FIG. 4 is an exploded perspective view showing a partial cross section of a flexible hose 2 according to another embodiment of the present invention. The same components as those in FIG. 2 are denoted by the same reference numerals, and a part of the description is omitted.
In this embodiment, the outer core 25 has a cross-sectional shape similar to that of the inner core 10. The embodiment of FIG. 2 is superior in flexibility, and in contrast to this, the embodiment of FIG. 4 is somewhat inferior in flexibility, but the inner core 10 and the outer core 25 are rectangular. Therefore, the structure is difficult to buckle. Therefore, the one shown in FIG. 4 has a large hose diameter and is suitable for applications requiring pressure resistance and shape retention.
Further, in FIG. 4, a metal wire conductor 23 as a ground wire is embedded in the protective layer 22, so that safety against static electricity can be ensured.

  The present invention can be used as an all-resin flexible pressure-resistant hose.

1, 2 Flexible hose 10 Inner core (PP)
11 Tube body 12 Film layer (fluororesin)
13 Film layer (PP)
14 Film layer (Fluororesin)
15 Outer core (PE)
16 Constrained layer 17 Elastomer layer 18 Woven yarn layer (polyester yarn)
19 Elastomer layer 20 Distribution layer (polyester yarn)
21 Outer winding layer 22 Protective layer 23 Ground wire

Claims (6)

The inner core (10) formed in a spiral shape is covered with the tube main body (11), and the outer cores (15, 25) formed in a spiral shape on the tube main body (11) are connected to the inner core (10). A flexible hose (1) in which a spiral concavo-convex surface is formed on the tube body (11) by being wound so as to form a double spiral structure,
The inner core (10) is formed into a square cross section by a resin material,
The tube body (11) is seamlessly molded from a resin material,
The outer core (15, 25) is formed of a resin material,
Further, on the outer side of the outer core (15, 25), the outer peripheral surface of the outer core (15, 25) is covered so as to be inwardly pressed and fused to the outer peripheral surface of the outer core (15, 25), Constraining layers (16, 17, 18) are formed that suppress the expansion of the outer core (15, 25) and the inner core (10) in the radial direction and limit the movement width of the outer core (15, 25). A flexible hose.   The flexible hose according to claim 1, wherein the constraining layer is formed of a woven yarn layer and an elastomer layer that sandwiches the woven yarn layer from the front and back sides and provides elasticity.   The flexible hose according to claim 1, wherein a cross section of the outer core is formed in a square shape.   The flexible hose according to claim 1 or 2, wherein a cross section of the outer core is formed into a circular shape or an elliptical shape.   A gap for enabling bending is provided between the outer core and the inner core adjacent to each other, and the gap is set so as to be in contact with the tube body in the most curved state. The flexible hose according to claim 1.   The flexible hose according to any one of claims 1 to 5, wherein a yarn distribution layer that tightens the outer region of the outer core and the outer region of the inner core as a whole is formed outside the constraining layer.