JP3192183B2 - Continuous production method of reinforced hose - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously producing a reinforced hose. More specifically, the present invention relates to a method for continuously producing a reinforcing hose used for an automobile power steering hose, a car cooler hose, and the like, and in particular, a reinforcing hose reinforced with fibers and having a rubber layer on at least the outer surface.

[0002]

2. Description of the Related Art Reinforcing hoses are usually composed of an inner layer, a reinforcing layer,
The outer layer is provided in this order, and in many cases, rubber is used for the inner layer and the outer layer.

In such a reinforcing hose, a reinforcing layer is formed on a mandrel and then a reinforcing layer is formed, and an outer rubber layer is formed by extrusion molding, and then formed with steam, a heat medium or the like.
It is manufactured by heating to 170 ° C and vulcanizing for about 0.5 to 1 hour to make the rubber elastic.However, the fluidity of the rubber increases at the initial stage of vulcanization, and it is difficult to maintain the shape as it is. Further, a method is generally practiced in which a coating (sheath) of lead, cloth, resin, or the like is applied to the outer periphery of the drum to keep the shape, and then wound around a drum and vulcanized.

[0004] After vulcanization, the sheath is peeled off using a blade or the like, the hose is taken out, the mandrel is also removed, and the sheath is wound into a predetermined shape. The removed sheath is usually
Reused.

[0005]

In the conventional method, a green hose is wound around a drum to perform vulcanization, so that a bent product remains in a product hose, and the insertability in a mounting process of a fitting or the like is deteriorated. An obstacle to automation. In addition, since the curvature varies depending on the size of the vulcanizing drum, there is a problem that an error is likely to occur in the hose length when cutting to a predetermined length.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, by combining a unique vulcanization step with a vulcanization step in a heating medium, a straight line is obtained. It has been found that a reinforced hose having good properties can be obtained, and the present invention has been completed.

That is, the present invention is a method for continuously producing a reinforced hose having an inner surface layer, a reinforcing layer, and an outer rubber layer on the outer periphery thereof. The radius of the hose heated from the outside of the TPX resin and then straight and coated with the TPX resin
After performing vulcanization by half revolution increments contact heating more slightly larger form of concave hot plates, it relates to a continuous process for producing reinforced hose, characterized in that retrieving the hose peeled the TPX resin.

[0008]

In the present invention, a green hose having an inner layer, a reinforcing layer, and an outer layer provided in this order on a mandrel is provided in the same manner as in the case of manufacturing a conventional reinforcing hose having at least an outer layer made of rubber. After being manufactured, the hose is coated with a TPX resin (trimethylpentene resin) so as not to lose its shape at the time of vulcanization and to prevent a hit on the outer surface of the hose, and then heated.

[0009] Except that at least the outer surface layer of the green hose is made of green rubber, the materials, thicknesses, and structures of the inner surface layer, the reinforcing layer, and the outer surface layer (whether each layer is a single layer or a multi-layer, or whether the reinforcing layer is a knitted fabric) It is a simple fibrous material, and furthermore, when the reinforcing layer is a multilayer, whether or not an intermediate layer exists between the reinforcing layers, and the like, and the forming method is not particularly limited. The material, layer thickness, structure, molding method, and the like used in the manufacture of the reinforced hose can be applied.

[0010] The use of TPX resin as the sheath is as follows.
This is because it has good high-temperature durability and releasability, low dielectric loss when high-frequency induction heating is used, and low cost. There is no particular limitation on the method of coating the TPX resin, the thickness of the layer, and the like, and a layer having a conventional thickness may be applied by a conventional method.

[0011] The heating is carried out by immersing in a direct thermal medium without wound on a drum a green hose coated with TPX resin, preferably is allowed to heat to the curing of the rubber begins, then straight in and the TPX Resin coating
Subjecting the host - a slightly larger form of concave hot plates than the radius of the scan is half lap increments contact heating vulcanization takes place.

In the present invention, heating with a heat medium is
This is because in steam heating, the pressure is high (about 5 kg / cm ² · G), and the danger of seal leakage is great.

A mandrel made of, for example, TPX resin having a wire core wire is used as a mandrel, and the wire core wire is heated (about 200 ° C.) by high-frequency induction heating before heating with a heating medium, so that the mandrel can also be heated from the inner layer side. Heating can be performed, and the heating time to the inner surface layer by the heat medium can be reduced.

The heating medium is not particularly limited, and can be used as long as it can be set to a predetermined temperature and does not dissolve the material to be used as a reinforcing hose. Examples thereof include a conventionally used silicone oil and a water-soluble or water-insoluble heat medium as described later.

Examples of the water-soluble or water-insoluble heat medium include, for example, those represented by the following general formula (I):

[0016]

Embedded image

(Wherein Y is an alkylene group having 1 to 5 carbon atoms or —SO ₂ −,-(A ₁ O) _m- or-(A
₂ O) _n -is -C ₂ H ₄ O- or -C ₃ H ₆ O
- and (or) -C a ₄ H ₈ O-and consists group, the number of repetitions of the unit is m or n, m + n is 4
To 30) (see, for example, JP-A-58-2378). Preferred among such water-soluble or water-insoluble heat media are those represented by the general formula (II):

[0018]

Embedded image

Wherein:-(A ₃ O) _p-and- (A ₄
O) _q -is -C ₂ H ₄ O- at 20% (% by weight, and so on)
A polyoxyalkylene group containing at least
17 and-(A ₃ O) _{p- and-} (A ₄ O) _q- may be any of homo, random and block types.

The use of the above-mentioned water-soluble heating medium makes it easy to remove the adhering oil after vulcanization, so that the TPX resin can be reused more times and the working environment is less polluted.
Erosion of PX resin is less in the case of polyethylene oxide-based heat medium having a cloud point, it is easy to separate and recover from the washing water, from the viewpoint of such.

In the above formula, if p + q is less than 6, the hydrophobicity is so strong that it is difficult to wash the sheath with water. If it exceeds 17, liquid separation from water becomes difficult, and if the thermal stability is not always sufficient. When the oxyethylene group content is less than 20%, hydrophobicity is strong, no cloud point phenomenon is observed, and it becomes difficult to separate the heating medium from the washing water.
Tends to erosion of the resin is increased.

Heating with a heat medium is preferably performed until the rubber starts to cure. After the rubber has already started to cure, a heat medium which is preferable in that it is quickly heated to the inner surface layer and uniformly cured is used. It is not necessary to use it, but rather the heat medium deteriorates by prolonged heating,
In order to reduce the erosion of TPX resin used as the sheath.

Usually, the temperature of the heating medium is about 160 to 200 ° C.,
The heating time of the hose is about 30 to 5 minutes.
At 0 ° C for about 20-30 minutes, at 180 ° C for about 10-20 minutes,
At 200 ° C., it takes about 2 to 5 minutes.

The heating by the hot plate after passing through the heat medium is carried out at a temperature of about 160 to 200 ° C.
Vulcanization is completed for about 4 minutes. At this time, the heating is preferably performed in a tunnel heating tank filled with air heated to the same degree as the hot plate. In this case, not only when the hot plate is in contact but also when the hot air is in contact with the hot plate In the meantime, the vulcanization proceeds in the same manner, so that the vulcanization can be performed uniformly and quickly.

The hot plate is a linear hot plate, and the portion of the hot plate through which the hose passes has a concave shape slightly larger than the half circumference of the sheath, so that the heat transfer effect is high in non-pressure vulcanization.
It is preferable from the viewpoints of good removability from the surface of the heat medium, small deformation, and prevention of vibration of the work in the apparatus.

A plurality of concave grooves formed by the hoses on the hot plate are formed in a straight line (FIG. 3 is an enlarged explanatory view of a portion of the straight hot plate vulcanizing step of FIG. 1 and FIG. 3A). -Please refer to FIG. 4 which is an enlarged explanatory view of A 'section), and this hot plate 1
A half of the hose 3 is brought into contact with the first concave shape 2 to travel and vulcanize, and a pulley 4 provided at the end of the first concave shape
The direction of travel of the hose is reversed by 180 °, and the half-circumferential side of the hose that is not in contact with the first concave shape is brought into contact with the second concave shape. . Since the apparatus having such a structure is used, the apparatus is compact and has good thermal efficiency. In addition, 5 in FIG. 3 is a heater, 6 is a hot air circulation device, 7 is a tunnel heating tank, and 10 in FIG. 4 is a heater.

The hose is heated half a round by the two sets of concaves on the hot plate, such as the first concave and the second concave, the third concave and the fourth concave, and vulcanization is performed. The vulcanization of the hose is performed once for each half of the concave shape on the hot plate in the set, and the vulcanization is repeated several times to complete vulcanization.

The number of reciprocations of the hose on the hot plate may be appropriately determined according to the length of the hot plate, the temperature, the running speed of the hose, and the like so that a predetermined vulcanization is performed on the hose.

Usually, the vulcanization carried out by using a heat medium and a hot plate together has a temperature of about 160 to 200 ° C. and a heating time of the hose of about 4 to 45 minutes. For example, at 160 ° C., about 34 to 42 minutes, 180 ° C. About 15 to 19 minutes at 200 ° C. for about 7 to 15 minutes. Although high-temperature vulcanization is preferable from the viewpoint of a short vulcanization time, vulcanization is preferably performed at a temperature of up to about 170 ° C. because the amount of by-product gas during vulcanization tends to deteriorate.

As described above, since the main vulcanization is carried out by immersing directly in a heat medium without being wound around a drum and then heating and then contacting with a hot plate and preferably a heated air, the heating can be carried out efficiently and uniformly. In addition, the product hose does not bend, the length error does not easily occur when the hose is cut, the insertability in the fitting process of the fitting is good, and the assembling process can be easily automated. In addition, since the vulcanization is performed while the hose surface is in contact with the hot plate and half-turned, deformation during vulcanization is noticed and a product having a good shape is manufactured. Further, since the vulcanization is performed by using the heating by the heating medium and the heating by the linear heating plate and preferably by the heating air in combination, the heating time by the heating medium can be shortened, and as a result, the deterioration of the heating medium hardly occurs. The sheath (TP
X resin) is less likely to occur, and the number of times TPX resin is reused increases dramatically.

After the vulcanization is completed, after the heat medium is removed, the sheath is cut off with a cutter, and the hose is wound around a predetermined drum or cut into a predetermined length. Note that the acquired curl generated by winding the drum after the hose has been formed can be easily returned to its original state by extending the curl when used.

The heat medium may be removed after the hose is heated with the heat medium and before the hose is heated with the hot plate, or after the hose is heated with the hot plate, or both.

When a water-soluble heat medium is used as the heat medium, the heat medium can be removed by washing with water, so that the heat medium can be easily and almost completely removed. As a result, the amount of the heat medium remaining in the collected sheath (TPX resin) is also reduced, which is preferable in that the number of times of reuse of the TPX resin is increased and contamination of the working environment is reduced. ) Is also preferable in that the erosion is small.

Next, the continuation in the method of the present invention will be described.

Although the method of the present invention relates to a method for continuously producing a reinforced hose, all steps from the step of forming an inner surface layer on a mandrel to the step of obtaining a product hose may be continuous. Need not be continuous.

For example, in the following steps showing an example of the steps of the present invention, the steps of forming the inner surface layer on the mandrel, forming the fiber reinforcing layer and forming the outer rubber layer, and winding or cutting the product are performed separately. Or may be performed continuously. However, the formation of the outer rubber layer ~
It is necessary to perform the hot plate vulcanization step continuously. If these steps are performed separately, the thermal efficiency is poor, there is an adverse effect due to moisture absorption, and once the winding is required, the molded product is likely to bend, and a large space is required for the apparatus.
And so on .

[0037]

[Table 1]

Next, the method of the present invention will be described based on examples.

Example 1 A reinforced hose having a polyamide layer and an inner rubber layer as an inner layer, a fiber reinforced layer, and an outer rubber layer on the outer periphery thereof was first manufactured according to the following steps.

[0040]

[Table 2]

FIGS. 1 and 2 show explanatory views of the steps so that the steps can be easily understood.
FIG. 2 shows a process from formation of a polyamide layer to a mandrel 8 to formation of an inner rubber layer and a process of forming a fiber reinforcement layer.
FIG. 1 shows the steps from the formation of the outer rubber layer to the cutting of the product.

The core has a steel wire of 3 mmφ,
A polyamide resin was extruded on the outer periphery of a mandrel 8 made of PX resin and having a diameter of 10 mm to form a 0.15 mm-thick thin tube as the innermost layer. Then, apply a chlorine-based adhesive around the periphery.
Apply uniformly to 1.5 g / m, and dry (150
℃ × 0.7 min), then isobutyl rubber (hardness HS8
0) was extruded to a thickness of 1 mm to form an inner layer, and then a polyester fiber reinforcing layer was formed on the outer periphery thereof by a braider 9. Next, the outer periphery is coated with EPDM (hardness HS75 (after vulcanization)) to a thickness of 1.5 mm by a rubber extruder, and TPX resin is further coated on the outer periphery with a thickness of 2.5 mm. Coated as heat resistant sheath. After that, high-frequency induction heating was performed under the condition that the mandrel core wire temperature was 200 ° C, heating was performed from the inside, and then the container was filled with 165 ° C silicone oil (1,800 l) for 23 minutes (immersed in silicone oil). Length 280 m),
While adding hot air at 165 ° C to the sheath,
The half-perimeter of the hose was brought into contact with a hot plate having eight concave straight grooves on the half-periphery of the hose, then the operation of inverting 180 ° and contacting the half-perimeter of the saw was repeated four times to perform vulcanization for 26.6 minutes. (Heating length by hot plate 40m x 8 times = 320
m). After that, the heating medium adhered to the surface was washed with an organic solvent (methyl ethyl ketone) and then washed with water. After that, the sheath was continuously peeled off with a cutter, and the mandrel was also removed. The inner surface layer was a composite layer of polyamide and rubber. And a continuous 400 m hose having a polyester fiber reinforcement layer and a rubber coating layer on the outer surface. this
It was cut to a length of 1.0 m.

In the above steps, after the EPDM coating, all the steps were continuously performed at 12 m / min. As a result, productivity was improved by continuation of the process.

The obtained hose has a good outer shape, does not bend, has no error in the length of the hose at the time of cutting, has good insertability in a fitting process of a fitting, and automatically performs an assembling process. But there was no problem.

Further, although the state of the heat medium after the production of the 2,000 m hose is not changed at all, the recovered TPX resin undergoes drying and pulverization steps, and cracks are generated on the surface by repeating five times (TPX resin). deterioration).

Example 2 The heat medium used was a polyoxyalkylene bisphenol A ether as a water-soluble heat medium (Unilube manufactured by NOF Corporation).
50DB-22, OHV144-160 (JIS K-1557 6.4), viscosity (100
C) 20.7-23.2 cst (JIS K 2283))
A reinforced hose was manufactured in the same manner as described above (however, washing was performed only with water).

The obtained hose has a good outer shape, does not bend, has no error in the length of the hose at the time of cutting, has a good insertability in a mounting process of a fitting, and automatically performs an assembling process. But there was no problem.

After the 20,000 m hose was manufactured, the state of the heat medium slightly changed to black, but no change was observed in the rise time and the fall time of the temperature. Recovered TPX
The resin was dried and crushed and used 50 times repeatedly.
There was no change in physical properties (elongation, tensile force).

Since the heat medium used was water-soluble, it could be easily removed by washing with water as compared with silicone oil, and no oil was mixed into the ground TPX.

[0050]

The hose obtained by the continuous manufacturing method according to the present invention is a hose having a good shape without bending and with little deformation, thereby facilitating the automation of the assembling process. In addition, the heating time by the heating medium is short, so that the deterioration of the heating medium and the TPX resin is small, and a good hose can be formed at low cost.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a process from formation of an outer rubber layer to cutting of a product among processes used in Example 1.

FIG. 2 is an explanatory diagram of a process from the formation of a polyamide layer on a mandrel to the formation of a fiber reinforcing layer in the processes used in Example 1.

FIG. 3 is an enlarged explanatory view of a part of a straight hot plate vulcanizing step of FIG. 1;

FIG. 4 is an enlarged explanatory view of an AA ′ section of FIG. 3;

[Explanation of symbols]

 1 hot plate 3 hose

────────────────────────────────────────────────── ─── front page continued (51) Int.Cl. ⁷ identifications FI B29L 23:00 (56) references Patent Sho 61-290011 (JP, a) (58 ) investigated the field (Int.Cl. ⁷ , DB name) B29C 35/00-35/18 F16L 11/08

Claims (1)

(57) [Claims] 1. A method for continuously producing a reinforced hose having an inner surface layer, a reinforcing layer, and an outer rubber layer on the outer periphery thereof, wherein the outer peripheral rubber layer is coated with a TPX resin and then directly heated in a heat medium.
X is heated from the outside of the resin, and then the TPX
E was subjected to resin coating - a slightly larger shape concave <br/> hot plate than the radius of the scan After performing vulcanization by half revolution increments contact heating, and characterized by taking out the hose peeled off the TPX resin Continuous production method of reinforced hose.