JPS6354239A - Production of hose with reinforcement layer - Google Patents

Abstract

PURPOSE:To easily produce a hose having a reinforcement layer comprising a fiber bundle embedded in a hose wall, by a method wherein the fiber bundle consisting of heat-shrinkable fibers impregnated with a thermosetting resin is wound around the outer peripheral surface of a cylindrical inner tube part formed of a thermoplastic resin, followed by heating to soften the inner tube part, then the fiber bundle is contracted to be embedded into the wall of the inner tube part, and the thermosetting resin is hardened. CONSTITUTION:A cylindrical inner tube part 1 is prepared which comprises a low melting point resin layer 11 on the outer side and a high melting point resin layer 12 on the inner side. A cord form fiber bundle constituted of heat- shrinkable polyester fibers is prepared, and the fiber bundle 2 to be impregnated with an epoxy resin is spirally wound around the outer peripheral surface of the inner tube part 1. Next, the inner tube part 1 with the fiber bundle 2 wound therearound is heated, whereby the fiber bundle 2 is embedded into the low melting point resin layer 11, but the high melting point resin layer 12 is not softened at this temperature. After hardening and cooling, a reinforcing yarn layer 3 is provided, and the surface of the object thus obtained is covered by extruding a skin layer 4 to produce a hose with a reinforcement layer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a method for manufacturing a hose having a reinforcing layer within the hose wall and having excellent kink resistance. The present invention can be used, for example, to manufacture air conditioner hoses for automobiles.

[Prior Art] If a hose made of rubber or resin is bent beyond a certain limit, it may buckle and collapse, making it impossible to secure a fluid flow path (hereinafter, this buckling phenomenon is referred to as kink). . In order to prevent this kink, a hose is known in which a reinforcing layer is formed by embedding a coil spring or the like in the hose wall. In such a hose, the reinforcing layer prevents the inner hose wall from penetrating into the hose hole when the hose is bent, thereby preventing kinking. J'3, the type of reinforcing layer is:
Coil springs made of gold a are common, but as shown in Japanese Utility Model Application No. 56-120480, there are also known springs in which a fiber bundle is impregnated with resin to strengthen it and then wrapped in a coil shape and buried. It is being

The hose having the above-mentioned reinforcing layer has conventionally been manufactured by using a coil spring, a resin-reinforced 11 gH bundle, etc. as an insert and integrally molding the hose with the bow body by extrusion molding, injection molding, etc.

[Problems to be Solved by the Invention] In a hose having a metal coil spring as a reinforcing layer, the coil spring increases the weight and is difficult to cut. Furthermore, when a large force is applied, the coil spring may be plastically deformed, and thereafter there is a problem in that the anti-kink performance deteriorates.

The above problems can be avoided by using a resin-reinforced fiber bundle. Here, the fiber bundle can be embedded and integrated within the hose body by tightly winding the fiber bundle impregnated with thermosetting $4 resin around the heat-softened hose body. However, when winding the hose, it is necessary to maintain the shape of the hose body by inserting a mandrel, etc., and this requires a lot of man-hours.

The present invention was made in view of these circumstances, and
The present invention provides a manufacturing method that can easily manufacture a hose having a reinforcing layer in which an aim bundle impregnated and solidified with a thermosetting resin is embedded in the hose wall.

[Means for Solving Corner Points] The method for manufacturing a hose having a reinforcing layer of the present invention is to apply a thermosetting resin to the outer circumferential surface of a cylindrical inner pipe portion made of a thermoplastic resin or unvulcanized rubber. A first step of winding a fiber bundle made of heat-shrinkable mm impregnated with mIf, heating the inner canal portion around which the mIf bundle is wound to soften the intraocular canal portion, and shrinking the fiber bundle. a second step of embedding into the wall of the intraocular canal, curing the thermosetting resin, and vulcanizing the inner canal if the internal canal is made of unvulcanized rubber; The method is characterized in that a reinforcing layer is formed by the fiber bundle impregnated and solidified with the thermosetting resin by sequentially carrying out the above steps.

In the first culm, the II fiber bundle is wound around the outer peripheral surface of the cylindrical inner tube. Here, the inner tube portion can be formed of thermoplastic resin such as polyethylene, polypropylene, polyamide resin, polyvinyl chloride, or various unvulcanized rubber materials. In this step, there is no need to soften the inner tube when the fiber bundle is wound around the inner tube. Therefore, there is no need to hold the inner tube part so as to maintain its shape, so it can be wrapped much more easily than in the past. Also, when wrapping it around, it is not necessary to wrap it tightly so that it is buried in the inner tube part.

Note that the shape of the winding can be a coil shape, a spiral shape, etc. as in the conventional case.

The greatest feature of the present invention is that the fiber bundle is formed from heat-shrinkable m-fibers. The thus wound fiber bundle is heated in a second step to be described later, thereby shrinking and being embedded in the softened wall of the inner tube. Note that heat-shrinkable fibers include polyester, vinylon, rayon, nylon, etc., and the fiber bundle can be a thread, string, etc. formed from fibers selected from these. Its thickness can be selected from various types depending on the shape of the hose.

The fiber bundle is impregnated with thermosetting resin. This thermosetting resin includes those in which the thermosetting resin itself is liquid before curing,
Alternatively, the thermosetting resin before curing is solid, and it can be dissolved in a solvent such as an organic solvent to form a liquid.

As such a thermosetting resin, phenol resin, epoxy resin, unsaturated polyester resin, etc. can be used. In particular, it is preferable to use an epoxy resin that has excellent adhesiveness to the fiber bundle and has good strength.

In the second step, the inner tube portion around which the sag bundle is wound is heated. This causes the fiber bundle to contract and become embedded in the softened inner tube. In addition, the thermosetting resin impregnated into the fiber bundle hardens,
A reinforcing layer is formed. Further, when the inner tube portion is made of unvulcanized rubber, it is once softened by heating and vulcanized and hardened after embedding the miscellaneous bundles. Here, the heating temperature needs to be at least higher than the shrinkage temperature of the heat-shrinkable fibers constituting the 11M bundle and higher than the heat deformation temperature of the inner tube.

This is because the curing reaction of the thermosetting resin and the vulcanization reaction of the unvulcanized rubber occur even at relatively low temperatures.

Note that it is desirable that the inner tube portion has an endothelial layer on its inner circumferential surface side that does not soften due to the heating in the second step.

This allows the contraction of the fiber bundle to be regulated by the endothelial layer. This makes it possible to prevent problems such as fiber bundles being exposed on the inner circumferential surface of the inner tube. Note that this inner skin layer is formed from a thermoplastic resin, soft thermosetting resin, vulcanized rubber, etc., which has a heat distortion temperature higher than the heating temperature in the second step, at the same time as the inner tube part, or is formed separately. It can be formed by bonding to the rear inner canal.

The obtained hose having the reinforcing layer may be used as a product by itself, or may further have a reinforcing thread layer, an outer skin layer, etc. formed on its outer peripheral surface. Further, the materials and formation methods of these layers can be the same as conventional ones.

[Function] In the manufacturing method of the present invention, in the first step, a la tA bundle impregnated with a thermosetting liquid resin is wound around the inner tube portion. Here, since the inner tube part has not softened, it has sufficient strength and does not need to be held to maintain its shape. This facilitates the first step.

Then, by heating in the second step, the fiber bundle shrinks and becomes embedded in the wall of the inner tube portion which has been softened by heat.

At the same time, the curing reaction of the thermosetting resin impregnated into the m-ray bundle is promoted by heating, and the fiber bundle is solidified within the inner tube wall to form a reinforcing layer. Further, if the inner tube portion is made of unvulcanized rubber, vulcanization can be performed at the same time.

[Effects of the Invention] According to the method for manufacturing a hose of the present invention, the fiber bundle made of heat-shrinkable 11M is shrunk by heating in the second step and buried in the softened inner pocket. As a result, a hose having a reinforcing layer in which a 1111 bundle impregnated with a thermosetting resin and solidified is embedded in the hose wall can be manufactured very easily. Therefore, it is possible to reduce costs by reducing the number of man-hours. The hose obtained by the manufacturing method of the present invention can be cut easily and has excellent kink resistance. Furthermore, even when a large force is applied, the reinforcing layer does not easily undergo plastic deformation unlike metals, so it maintains stable kink resistance.

[Example] This will be explained in detail below using Examples.

Maffi deformation ff1 degree (4,6kq/cm2) 150
℃ modified nylon 6 resin and a modified nylon 12 resin with a heat distortion temperature of 100 degrees Celsius or less are extruded in two colors, and as shown in Figure 2, the outside is made of modified nylon 12 resin with a heat distortion temperature of 100 degrees C or less. A cylindrical inner tube portion 1 was prepared, which was made up of a low melting point resin layer 11 and a high melting point resin layer 12 formed from a modified nylon 6 resin having a heat deformation temperature of 150° C. on the inside.

(First step) A string-like fiber bundle made of heat-shrinkable polyester TA fibers was prepared, and impregnated by immersion in a liquid resin made of epoxy resin (for example, Ciba Geigy, Araldite and its curing agent). . Then, as shown in FIG. 3, the fiber bundle 2 impregnated with this resin was wound spirally around the outer circumferential surface of the inner tube portion 1 and numbered. Note that the polyester fibers constituting this fiber bundle 2 shrink at about 140° C., and the shrinkage rate is about 10%.

(Second Step) Next, the inner tube portion 1 around which the fiber bundle 2 was wound was placed in a heating furnace and heated to 150°C. At this temperature, the low melting point resin layer 11 softens and the fiber bundle 2 contracts. As a result, the fiber bundle 2 is buried in the low melting point resin layer 11. However, at this temperature,
The melting layer resin layer 12 does not soften, and the fiber bundle 2 has a low melting point resin layer 1.
1 is prevented from shrinking toward the inner circumference. By holding this temperature for 15 minutes, the epoxy resin impregnated into the fiber bundle 2 was cured to form a reinforcing layer.

After curing and cooling, the polyester yarn is braided onto the inner tube part 1 to form a reinforcing yarn WJ3, and an outer skin layer 4 made of polyamide thermoplastic resin is further extruded on the surface of the reinforcing yarn layer 3 using an extruder to cover it. A hose having a reinforcing layer as shown in FIG. 1 was manufactured by forming the hose.

FIG. 4 shows a bent state of the hose obtained in this example. In the bent part, tensile stress acts on the outside and compressive stress acts on the inside. Then, on the inside where compressive stress acts, the hose wall tries to enter the hose hole. However, the thermosetting resin was impregnated and solidified.
Since the coil-shaped reinforcing layer made of fiber bundles is densely embedded, the hose wall is prevented from penetrating and kinks are prevented. Furthermore, a spiral groove is formed in the inner tube by contraction of the fiber bundle, and this groove improves flexibility.

In addition, the 1q hose in this example is lightweight and easy to cut. Even when a large force is applied, the reinforcing layer is less likely to undergo plastic deformation unlike metals, so it maintains stable kink resistance.

[Brief explanation of the drawing]

The drawings relate to one embodiment of the present invention, and FIG.
FIG. 2 is a perspective view of the inner tube, FIG. 3 is a perspective view showing the state in which the first step of winding the fiber bundle is being performed, and FIG. 4 is a cross-sectional view showing the structure of the hose. FIG. 3 is a partial cross-sectional view showing a bent state of the hose.

Claims (2)

[Claims] (1) A first step of wrapping a fiber bundle made of heat-shrinkable fibers impregnated with a thermosetting resin around the outer peripheral surface of a cylindrical inner tube portion made of a thermoplastic resin or unvulcanized rubber, and the fibers. heating the inner tube portion around which the bundle is wound to soften the inner tube portion, shrink the fiber bundle and embed it within the wall of the inner tube portion, and harden the thermosetting resin; When the inner tube part was formed of unvulcanized rubber, a second step of vulcanizing the inner tube part was carried out in sequence, and a reinforcing layer was formed by the fiber bundle impregnated with the thermosetting resin and solidified. A method for manufacturing a hose having a reinforcing layer, characterized by: (2) A method for manufacturing a hose having a reinforcing layer as set forth in claim 1, wherein the inner tube portion has an inner skin layer on its inner circumferential surface that does not soften due to heating in the second step.