JP4170811B2 - Manufacturing method of rubber hose with film intermediate layer - Google Patents

Description

【表２】

【表３】

【表４】

【表５】

【図面の簡単な説明】
【図１】成形装置全体を示す図
【図２】押出成形時におけるフィルムの変化を示す図
【図３】押出ヘッド内の要部拡大断面図
【図４】図１の４−４線に略沿う断面図
【図５】誘電加熱を示す断面図
【図６】オーバーラップ部の構造例を示す図
【図７】同上図
【図８】同上図
【図９】同上図
【符号の説明】
１：ゴムホース、２：中間層、３：内層ゴム、４：外層ゴム、５：フィルム、８：長辺部、１０：成形装置、１１：押出ヘッド、２０：溶着装置、２１：発振機、２５：加熱コイル[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a liquid or gas transport hose, and more particularly to a method of extruding rubber inside and outside an intermediate layer in a state where a resin film or the like is rolled into a cylindrical shape and ends are overlapped.
[0002]
[Prior art]
As an extrusion molding of a liquid or gas transport hose, it is continuously fed into an extrusion head while rounding a film made of resin having a long strip shape and having resistance to permeation into a cylindrical shape and overlapping the ends, It is known that the inner and outer layer rubbers are simultaneously extruded into the inside and outside. At this time, it is also known that the end portion of the film is weakened to facilitate the formation of the overlap portion, or vacuum suction is performed so that the overlap portion maintains close contact.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-169061 [Patent Document 2]
JP 2002-172777 A [Patent Document 3]
JP 2003-65465 A [Patent Document 4]
JP 2003-65468 A [0004]
[Problems to be solved by the invention]
In the conventional coextrusion molding method, since an overlap portion exists in the intermediate layer film, it is necessary to prevent a decrease in permeation resistance due to the opening of the overlap portion. In particular, after extrusion, when a straight tubular semi-vulcanized hose cut to a predetermined size is attached to a mandrel and bent into a curved tube, the overlap portion is displaced and a gap is likely to be generated. Such a shift of the overlap portion can occur even when the extrusion is performed by vacuum suction.
[0005]
Therefore, it is conceivable that the overlap portion is welded by external heating using a gear oven or the like in a straight pipe state before the mandrel is mounted. However, in this case, since heating for about 200 ° C for a long time is necessary, the rubber is deteriorated, or the vulcanization proceeds and it becomes difficult to bend the tube by attaching the mandrel after that. This is not a practical method. An object of the present invention is to solve such problems and to reliably weld and integrate the overlap portion.
[0006]
[Means for Solving the Problems]
Claim 1 of the present invention for solving the above problems, and supplies to the strip-like film edges are overlapped together by extrusion in the head rounded to by cormorants circular cylindrical form the overlap portion, inside and outside of the film In the method of forming a rubber hose having a film intermediate layer by extruding the inner layer rubber and the outer layer rubber, the overlap portion is made of a magnetic body or a conductor structure, and the extruded raw material is sandwiched between the outer layer rubber and the inner layer rubber. The overlap portion is dielectrically heated from the outside and welded by a welding device disposed on the outer periphery of the hose.
[0007]
A second aspect of the present invention is characterized in that, in the first aspect, the magnetic body or conductor structure is formed by integrating or interposing the magnetic body or conductor separate from the film into the overlap portion.
[0008]
In Claim 3 and Claim 1, the film is a metal single layer made of a magnetic material or a conductor, or a laminate of this and a resin film.
[0009]
In Claim 4 and Claim 1, the film is a resin in which a magnetic material or a conductor is integrated.
[0010]
In claim 5 and claim 1, the overlap portion is reduced in pressure in the extrusion head and is in close contact.
[0011]
【The invention's effect】
According to the first aspect, since the overlap portion has a magnetic body or conductor structure, when the overlap portion is dielectrically heated from the outside of the extruded raw hose, the overlap is shortened due to heat generation of the magnetic body or conductor structure. Weld in time.
Therefore, since it can process immediately and continuously with respect to the raw hose extruded, a continuous extrusion molding of a hose is possible. Moreover, since the heating range is local, it hardly affects the surrounding rubber layer, and as a result, thermal deterioration of the rubber layer can be prevented. In addition, even if there is a step due to the overlap portion, the step can be largely eliminated by welding.
[0012]
Further, since the heating is performed for a short time, vulcanization is not promoted, and it becomes possible to form and vulcanize a curved tube by mounting a mandrel thereafter. Moreover, since the overlap part is welded at this time, it does not open even if the overlap part is bent together with the raw hose, it can maintain high permeation resistance, and high permeation resistance such as fuel hose It is suitable for rubber hoses for applications that require
[0013]
In addition, since this dielectric heating can perform non-contact external heating on the raw hose immediately after extrusion, it can be easily added before a relatively long cooling step provided after extrusion on a conventional production line. It can eliminate the need for major renovation of the production line and can be easily incorporated into existing equipment.
[0014]
According to claim 2, since the magnetic body or conductor separate from the film is integrated or interposed in the overlap portion to form a magnetic body or conductor structure, for the resin film or the like normally used as an intermediate layer However, it is possible to easily provide a magnetic or conductive structure that enables dielectric heating.
[0015]
According to claim 3, since the film of the intermediate layer is composed of a single layer of metal made of a magnetic material or a conductor or a laminate of this and a resin film, these overlapping portions themselves generate heat due to dielectric heating. Weld. For this reason, it is not necessary to form a magnetic body or conductor structure using a separate magnetic body or conductor.
[0016]
According to the fourth aspect, since the film of the intermediate layer is a resin and the magnetic body or the conductor is integrated therein, the magnetic body or the conductor generates heat by dielectric heating in the overlap portion. As a result, the surrounding resin is welded. For this reason, it is not necessary to form a magnetic body or conductor structure using a separate magnetic body or conductor.
[0017]
According to the fifth aspect, since the pressure between the intermediate layer, the inner layer rubber and the outer layer rubber is reduced in the extrusion head, it is possible to maintain the close contact until the overlap portion is welded. For this reason, it can prevent effectively that an overlap part opens before welding.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments will be described below with reference to the drawings. FIG. 1 is a diagram schematically showing the entire molding apparatus, and FIG. 2 is a diagram showing changes in the film during simultaneous extrusion molding. As shown in FIGS. 1 and 2, the rubber hose 1 of this embodiment includes an inner layer rubber 3 made of an appropriate elastic material such as rubber on the inner side of an intermediate layer 2 made of an inorganic film such as resin or metal, and an outer layer rubber 4 on the outer side. It was obtained by simultaneously extruding these.
[0019]
The film 5 constituting the intermediate layer 2 is rounded into a cylindrical shape and partially has an overlap portion 6. In this overlap portion 6, the long side portions (both end portions in the width direction orthogonal to the longitudinal direction) 8, 8 of the film 5 overlap each other with a predetermined width. At least the overlap portion 6 has a magnetic or conductive structure that generates heat and is welded by electromagnetic dielectrics. Details of this will be described later. In addition, although the film 5 and the intermediate | middle layer 2 are the same, the part before extrusion molding is called the film 5 especially.
[0020]
The principle of the molding method of the rubber hose by bending in the extrusion head will be described with reference to FIG. First, the belt-like film 5 is continuously supplied from the raw fabric roll 9 to the extrusion molding machine 10, and the film 5 is supplied to the intermediate passage 12 of the extrusion head 11 while being rounded and formed into a cylindrical shape. The intermediate passage 12 is a passage for supplying the film 5, has a ring shape, and is provided in the intermediate layer forming portion 13 that is a part of the extrusion head 11.
[0021]
An inner passage 14 for inner layer rubber is provided inside the intermediate layer forming portion 13, and an outer passage 15 for outer layer rubber is provided on the outer side, and raw rubber for forming inner and outer layers is supplied to each. These three passages join at a joining portion 16a near the entrance of the collecting passage 16, and are pushed out through the collecting passage 16 as a rubber hose 1 in which three layers are integrated.
[0022]
The intermediate passage 12 is decompressed to a predetermined degree of decompression lower than the atmospheric pressure by connecting to a vacuum pump 17 that is a decompression device, and this decompression extends to the collecting passage 16 through the intermediate passage 12. Therefore, the inner and outer layers 3 and 4 are laminated and integrated with the intermediate layer 2 with a high degree of adhesion. For convenience, two vacuum pumps 17 are shown in the figure, but the actual intermediate passage 12 is a single ring-shaped member, and one vacuum pump 17 is connected to this.
[0023]
The rubber hose 1 in a state immediately after the extrusion molding is an unvulcanized or semi-cured raw rubber hose, and immediately after the extrusion, the overlap portion is instantaneously welded from the outside by local heating by electromagnetic dielectric by the welding device 20. An oscillator 21 is connected to the welding apparatus 20.
[0024]
Then, after passing through a cooling tank or the like and cooling to a predetermined temperature, the raw rubber hose is cut to a predetermined size by a cutter 18 to obtain a straight tubular hose 1 (the size shown in the figure is reduced), which is not shown 3 It was attached to a curved mandrel bent in a complex direction and vulcanized by heating to the vulcanization temperature for a predetermined time in a vulcanizer, etc., and completed in various curved shapes such as a three-dimensional direction. Product rubber hose.
[0025]
FIG. 2 schematically shows the intermediate layer forming portion 13 of the extrusion head 11 for the sake of convenience in order to schematically explain the simultaneous extrusion molding. In this figure, the film 5 formed in a planar shape and a long belt shape is continuously fed into the intermediate layer forming section 13 along the feeding direction A. At this time, the film 5 gradually changes in shape from the initial planar shape B to the conical shape C and the cylindrical shape D in the process of being sent into the intermediate layer forming portion 13.
[0026]
That is, the long side portions 8 and 8 on the left and right with respect to the feeding direction (extrusion direction) A are overlapped in the intermediate layer forming portion 13 to form an overlap portion 6 and the film 5 is a cylindrical shape rounded into a circular cross section. D is formed, but in the vicinity of the entrance of the intermediate layer forming portion 13, the conical portion C is formed as an intermediate form that shifts from the planar shape B to the cylindrical shape D. In this conical portion C, both long side portions 8 of the film 5 begin to bend toward each other and gradually form an overlap portion 6.
[0027]
When the film 5 forms the cylindrical shape D in the intermediate layer forming portion 13 in this way, the rubbers of the inner layer rubber 3 and the outer layer rubber 4 are then extruded into and out of the extrusion head 11 so that these three layers are integrated. A hollow rubber hose 1 is simultaneously extruded and extruded from the extrusion head 11.
[0028]
3 is an enlarged cross-sectional view for explaining the overlap portion 6 portion in the vicinity of the merge portion 16a in FIG. 1, and FIG. 4 is a view in FIG. 1 for showing the state of the intermediate layer 2 in the intermediate layer forming portion 13. FIG. As shown in these drawings, the intermediate layer forming portion 13 is formed in a tapered shape that tapers toward the joining portion 16a, and the opening width on the outlet side of the intermediate passage 12 facing the joining portion 16a is the thickness of the overlap 6. It is about.
[0029]
For this reason, on the outlet side of the intermediate passage 12, the upper and lower films 5, 5 constituting the overlap portion 6 are brought into close contact with the intermediate layer forming portion 13. Moreover, since the inside of the intermediate passage 12 is decompressed so that the decompression direction is schematically shown by the white arrow in FIG. 3, the upper and lower films 5, 5 are also decompressed in the overlap portion 6, and each is strongly adhered. Thus, foreign matters such as volatile matter in the overlap portion 6 are removed by suction, and the occurrence of a phenomenon in which the volatile matter expands and foams during heating in the subsequent vulcanization step can be prevented.
[0030]
Further, as shown in FIG. 4, a portion of the film 5 other than the overlap portion 6 forms a slight gap 19 with the outlet side portion of the intermediate passage 12, so that it is connected to the intermediate passage 12 through this gap 19. The evacuating pump 17 can simultaneously depressurize the merging portion 16a shown in FIG.
[0031]
Accordingly, the film 5 is sent to the joining portion 16a while the upper and lower films 5 and 5 are in close contact with each other at the overlap portion 6 where the inner layer rubber 3 and the outer layer rubber 4 are integrated. However, even if it is a hard thing which cannot keep the overlap part 6 closely_contact | adhering, it can make it contact | adhere reliably and can perform simultaneous extrusion molding. In addition, since the bending process in the extrusion head is possible, it can be mass-produced with high efficiency.
[0032]
At this time, as clearly shown in FIG. 3, a high vacuum is maintained up to the merging portion 16 a, so that foreign substances such as gas such as air and volatile matter can be removed. It can be integrated with a high degree of adhesion, and the occurrence of a phenomenon in which volatile components expand and foam during heating in the subsequent vulcanization process can be prevented. In addition, since the outer layer rubber 4 and the inner layer rubber 3 receive force in a direction approaching each other by being maintained at a high vacuum up to the joining portion 16a, it is possible to integrate more strongly.
[0033]
As shown in FIG. 5, the raw rubber hose 1 extruded as described above is welded to the overlap portion 6 by the welding device 20 immediately after exiting the extrusion head 11. The welding device 20 includes a guide portion 22 and a receiving jig 23 that are disposed to face each other with the raw rubber hose 1 interposed therebetween. The receiving jig 23 is made of an insulator and includes a concave groove 24 into which at least a portion including the overlap portion 6 of the raw rubber hose 1 is inserted, and a heating coil 25 is embedded and integrated in the vicinity thereof.
[0034]
When a high frequency current of a predetermined cycle is sent from the oscillator 21, the heating coil 25 forms a high frequency magnetic field in the vicinity of the concave groove 24, and instantaneously heats the magnetic body or conductor located in the concave groove 24. Therefore, when the magnetic material or the conductor exists in the overlap portion 6, the overlap portion 6 generates heat and is welded by the heating heating by the heating coil 25. Since this welding is performed instantaneously and locally, it hardly affects the surrounding outer layer rubber 4 and inner layer rubber 3 and the like, and does not deteriorate them.
[0035]
The structure of the receiving jig 23 is an example, and various other structures are possible. When the width of the overlap portion 6 is narrow, it can be formed into a flat plate shape without providing the groove 24. In this way, the structure becomes simple and versatility is enhanced because hoses having various outer diameters can be used in common.
[0036]
6 to 9 schematically show various structural examples of the overlap portion 6. In FIG. 6, a magnetic or conductive layer 26 is formed on the outer side of the overlap portion 6 where the long side portions 8 and 8 of the film 5 made of thermoplastic resin are overlapped. In this way, the welding of the overlap portion 6 instantly is performed by Ri磁 material element or the conductive layer 26 by the dielectric heating to melt the long side portions 8 with heating.
[0037]
Such a magnetic body or conductor layer 26 can be formed of a conductive metal foil tape or the like, and can be previously laminated on the long side portion 8 on one side. Moreover, it is also possible to simply overlap the long side portion 8 without being integrated. In addition, metal powder can also be made to adhere by the width | variety of the overlap part 6. FIG. Further, metal wires can be used in the same manner.
[0038]
Further, as shown in FIG. 7, the magnetic material or conductor layer 26 can be made inside by reversing the way in which the long side portions 8, 8 overlap in the overlap portion 6. In this case as well, dielectric heating can be performed, and in particular, the upper and lower long sides 8 and 8 can be evenly heated. On the other hand, since the magnetic body or conductor layer 26 approaches the heating coil 25 as shown in FIG. 6, the heat generation efficiency is increased accordingly. In addition, the magnetic body or the conductor layer 26 can also be arrange | positioned in the lowest layer (inner layer rubber | gum 3 side).
[0039]
FIG. 8 shows an example in which the film 5 itself is formed of a magnetic material or a conductive material. In this way, dielectric heating can be performed without providing a separate magnetic material or conductive layer 26 on the overlap portion 6 in particular. . In this case, when a metal film 5 with excellent permeation resistance is used as the intermediate layer 2, if the magnetic material or the conductor is used, the metal long sides 8, 8 themselves are welded together by dielectric heating. It is the most efficient because it can. Moreover, the overlap portion 6 can be made as thin as possible.
[0040]
Moreover, what knead | mixed magnetic materials or conductor materials, such as metal powder, in the thermoplastic resin may be used for the film form. Furthermore, if the metal film of a magnetic body or a conductor is laminated, the metal film itself forms a magnetic body or a conductor layer, and other laminated resin layers can be heated and welded by the generated heat. This is advantageous because it can contribute to the improvement of permeation resistance of the entire hose.
[0041]
FIG. 9 shows an example in which the entire film 5 is not made of a magnetic material or a conductor, and only the long side portions 8 and 8 are made of a magnetic material or a conductor structure. In addition, a magnetic material such as metal foil or metal powder or a conductive material is embedded and integrated to form a magnetic material or conductor structure. In this way, the separate magnetic body or conductor layer 26 can be omitted.
[0042]
Thus, if the overlap part 6 is welded by dielectric heating, the overlap part 6 can be welded instantaneously. Therefore, since the raw hose 1 to be extruded can be processed immediately and continuously, the hose can be continuously extruded. Moreover, since the heating range is local, it hardly affects the surrounding rubber layer, and as a result, thermal deterioration of the rubber layer can be prevented. Moreover, even if there is a step due to the overlap portion 6, the step can be greatly eliminated by welding.
[0043]
Further, since the heating is performed for a short time, vulcanization is not promoted, and it becomes possible to form and vulcanize a curved tube by mounting a mandrel thereafter. And since the overlap part 6 is welded at this time, even if the overlap part 6 is bent with a raw hose, it does not open | release and it can maintain high permeation resistance.
[0044]
In addition, since this dielectric heating can perform non-contact external heating on the raw hose 1 immediately after extrusion, it can be easily added before a relatively long cooling step provided after extrusion on a conventional production line. It is possible to eliminate the need for major renovation of the production line, and it can be easily incorporated into existing facilities.
[0045]
Further, since the pressure between the intermediate layer 2 and the inner layer rubber 3 and the outer layer rubber 4 is reduced during extrusion, the overlap portion 6 can maintain adhesion until welding. For this reason, it can prevent effectively that the overlap part 6 opens before welding. However, this decompression means is not essential and may be omitted depending on the conditions.
[0046]
Next, the rubber hose 1 and its constituent parts will be described in detail. The total thickness of the rubber hose 1 including the thicknesses of the intermediate layer 2, the inner layer rubber 3 and the outer layer rubber 4 is about 5.0 mm, which is much higher than the conventional one of about 1.5 to 3.5 mm. It can also be a thin hose. In the present application, the thin-walled hose refers to a hose in this thickness range. The total thickness of the intermediate layer 2 is preferably in the range of 0.01 mm to 1.00 mm.
[0047]
The film 5 constituting the intermediate layer 2 is made of an inorganic film such as a thermoplastic resin or a metal excellent in permeation resistance, and has a film bending load (100 mm width, 0.05 mm thickness) of 400 N or more. In the case of a resin film, a thermoplastic resin film having a melting point of 50 ° C. or higher and 300 ° C. or lower is preferable. For example, THV500 and THV610G (trade name of Sumitomo 3M Limited; ternary fluorine-based resin) or nylon 12 is used. .
[0048]
Examples of such resin film materials include LDPE, LLDPE, HDPE, PP, PET, PBT, PA6, PA66, PA11, PA12, PPS, PVDC, PVC, PVA, ethylene vinyl alcohol copolymer, fluororesin (single weight A resin such as a polymer, a binary polymer, or a ternary polymer) is selected according to the application from the viewpoint of strength, pressure resistance, permeation resistance, melting point, heat resistance, flexibility resistance, price, and the like. The film can be produced by either inflation film molding or T-die molding. Both molding methods can be multilayer extrusion, and films extruded separately can be bonded together in a subsequent process.
[0049]
The multilayer resin film has a multilayer structure of 2 layers to a maximum of 5 layers, and if the melting point of at least the innermost layer or the outermost layer resin film is lower than the vulcanization temperature of the hose, the overlapping portion of the film is vulcanized in the vulcanization process. Can be fused at the same time. If the overlap portion is fused, the pressure resistance and permeation resistance are improved as compared with the unfused hose. It is possible to perform film welding by providing a heating step before and after the vulcanization step, which is effective when the vulcanization temperature of the rubber material and the melting point of the resin layer are greatly different from each other.
[0050]
In addition, when a resin having excellent permeation resistance but having a low melting point is used, the low melting point resin can also be applied by laminating a resin having excellent heat resistance on both sides. If multilayered as described above, characteristics can be compensated for between different resins, and the possibility of pinholes generated in the film manufacturing process becomes smaller as the multilayer structure is formed. It is also possible to make the total thickness of the film thinner with the same performance as the single layer film.
[0051]
The inorganic film such as a metal used for the film 5 is preferably aluminum that is lightweight and can be easily thinned. The aluminum single layer, or a laminate of the resin single layer or multilayer film and the aluminum foil, and further the resin single layer or laminate A structure in which aluminum is vapor-deposited on the film is desirable. As a laminated body close to aluminum vapor deposition, a film in which a ceramic containing silica, alumina oxide, or the like, or an inorganic material such as copper, brass, stainless steel, or iron is vapor-deposited or bonded to the resin single layer or laminated film can be used. If such a film is used, the content liquid or the content gas can be completely impermeable.
[0052]
In addition, when using these films 5, it is necessary to provide a magnetic body or conductor structure as shown in FIGS. That is, when the film 5 is made only of a resin, or when a non-magnetic material or conductor is used as an inorganic film, a separate magnetic material or conductor layer 26 is provided as shown in FIG. A structure in which the long side portion 8 such as 9 is partially made into a magnetic material or a conductor is adopted. Further, when a magnetic film or a conductive metal film is laminated as the inorganic film, the film itself becomes a magnetic body or a conductor layer, which corresponds to the case of FIG. 8, and is a separate magnetic body or conductor layer. 26 can be used without being formed.
[0053]
The rubber material forming the inner rubber layer 3 and the outer rubber layer 5 is NBR, SBR, FKM, BR, CR, IIR, CSM, ECO, EPDM, silicone rubber, etc., with permeation resistance, strength, heat resistance, weather resistance, It can be selected from chemical properties, oil resistance, cold resistance, hardness, specific gravity, price, etc. based on required characteristics, and the inner and outer layers can be manufactured in a maximum three-layer structure by combining the same material or different materials.
[0054]
The present invention is not limited to the above-described embodiments, and various modifications and applications can be made within the principle of the invention. For example, an extruding head outer bending process in which the film 5 is shaped by another means other than the extruding head so as to bend the film 5 in the width direction in front of the extruding head 11 may be employed. If it does in this way, it will become possible to use a higher elastic modulus film.
[0055]
Moreover, the hose of this invention can be shape | molded by the crosshead method, and a film can be wound helically and it can be made cylindrical. In this case, since the overlap portion is formed in a spiral shape, the welding apparatus 20 is configured in a ring shape, and the raw hose is passed through the ring-shaped hole, so that the dielectric heating is similarly performed instantaneously. Can be welded.
[0056]
Examples are shown below. In Example 1 shown in Table 1, the inner layer rubber 3 and the outer layer rubber 4 are each nitrile rubber (NBR) having a thickness of 2.0 mm, the intermediate layer 2 has a total thickness of 0.14 mm, and nylon 12 (PA12, 60 μm), aluminum (20 μm), and nylon 12 (60 μm). A raw hose having this configuration is formed by the coextrusion molding. For the obtained raw hose, welding is performed by changing the output of the welding device in five stages of 50 KHz, 100 KHz, 200 KHz, 300 KHz, and 400 KHz, and the heating time for each is from 1 to 5 seconds in 1 second increments immediately after extrusion. An evaluation test is performed to evaluate the fused state of the overlap portion and the rubber state every second.
[0057]
Table 5 shows the evaluation criteria. In the fused state, the peel strength test of the overlap part is performed, and when the defect is not visually confirmed with a value of 20 N / cm or more, it can be accepted (◯), and the value less than 20 N / cm or the defect can be visually confirmed. It will be rejected (x).
The rubber state is determined to be acceptable (◯) when changes such as foaming cannot be visually confirmed in the rubber layer, and is rejected (×) when changes such as foaming can be visually confirmed.
[0058]
Table 2 shows the results of the evaluation test. As is apparent from this table, when the heating time is 1 to 3 seconds, the output is passed at 300 KHz or more. At 4 seconds, the output is acceptable at 200 KHz or more, but at 400 KHz, the rubber deteriorates. Therefore, 200 to less than 400 KHz is possible. Furthermore, in 5 seconds, it becomes possible at 200 to less than 300 KHz.
[0059]
In Example 2 shown in Table 3, the inner layer rubber 3 and the outer layer rubber 4 are each an epichlorohydrin rubber (ECO) having a thickness of 2.0 mm, and the intermediate layer 2 is the same as in Example 1. A raw hose having this configuration is formed by the coextrusion molding, and the same as in Example 1. Table 4 shows the results. In this example, the same results as in Example 1 are obtained as is apparent from Table 4.
[0060]
[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Brief description of the drawings]
FIG. 1 is a diagram showing an entire molding apparatus. FIG. 2 is a diagram showing changes in a film during extrusion molding. FIG. 3 is an enlarged cross-sectional view of the main part in the extrusion head. FIG. 5 is a sectional view showing dielectric heating. FIG. 6 is a diagram showing an example of the structure of an overlap portion. FIG. 7 is the same as the above. FIG. 8 is the same as the above. FIG. 9 is the same as the above.
1: rubber hose, 2: intermediate layer, 3: inner layer rubber, 4: outer layer rubber, 5: film, 8: long side part, 10: molding device, 11: extrusion head, 20: welding device, 21: oscillator, 25 : Heating coil

Claims (5)

A strip of film together overlapping edges supplies rounded to by cormorants circular cylindrical form the overlap portion into the extrusion head, with a film intermediate layer by extruding the inner layer rubber and the outer layer rubber into and out of the film In a method of molding a rubber hose,
The overlap portion is made of a magnetic material or a conductor structure, and is sandwiched between outer layer rubber and inner layer rubber, and the overlap portion is dielectrically heated from the outside by a welding device disposed on the outer periphery of the extruded raw hose. A process for producing a rubber hose having a film intermediate layer, characterized by welding. 2. The method for producing a rubber hose having a film intermediate layer according to claim 1, wherein the magnetic body or the conductor layer is formed by integrating or interposing the magnetic body or conductor separately from the film in the overlap portion. 2. The method for producing a rubber hose having a film intermediate layer according to claim 1, wherein the film is a single layer of metal made of a magnetic material or a conductor or a laminate of the metal and a resin film. The method for producing a rubber hose having a film intermediate layer according to claim 1, wherein the film is a resin in which a magnetic material or a conductor is integrated. The method for producing a rubber hose having a film intermediate layer according to claim 1, wherein the overlap portion is depressurized and closely adhered in the extrusion head.

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