JP2008132727A - Mandrel for molding bent hose and method of manufacturing resin/rubber-composite bent hose using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mandrel for molding a bent hose which enables low-cost and high-precision manufacture of high-quality resin/rubber-composite bent hoses which have a complicated three-dimensional shape and are free of flaws in their inside surfaces. <P>SOLUTION: The mandrel 1 is used to mold a resin/rubber-composite bent hose which is coated with two or more rubber layers and a reinforcing layer(s) arranged between the rubber layers, formed on the outer surface of a resin tube, and consists of a flexible tube 2 and a rubber layer 3 coated on the outer periphery of the flexible tube 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mandrel for forming a bent hose and a method for producing a resin-rubber composite bent hose comprising a resin layer and a rubber layer using the mandrel, and more specifically, for an air conditioner for a vehicle such as an automobile. The present invention relates to a method for producing a resin-rubber composite bent hose used in a refrigerant circuit or the like.

  In recent years, aluminum alloy pipes have been used in piping for refrigerant circuits of vehicle air conditioners for the purpose of reducing the weight of vehicles such as automobiles. However, vibration generated by a compressor or the like may resonate the pipes and cause noise. There is. Therefore, in order to suppress the resonance of the pipe, a composite flexible hose made of rubber and resin is used in the middle of the pipe.

  In such a composite flexible hose used in the refrigerant circuit of such a vehicle air conditioner, the inner tube is generally configured as a resin-rubber composite structure having a resin layer and a rubber layer. Further, the thin resin layer provided in the innermost layer ensures gas permeation resistance to the refrigerant, and the outer layer rubber hose ensures flexibility, vibration absorption and moisture permeation resistance as a hose, and further the rubber layer It is usual to have a fiber reinforcing layer for reinforcing the fiber with fibers.

  In general, as the resin that forms the innermost layer of the refrigerant resin-rubber composite hose of the vehicle air conditioner, a polyamide-based resin is mainly used. Further, examples of the rubber forming the refrigerant resin-rubber composite hose include butyl rubber, chlorinated butyl rubber, brominated butyl rubber, and ethylene-propylene-diene copolymer rubber (hereinafter abbreviated as EPDM).

  However, in recent years, the piping space has become narrower and more complicated due to the reduction in weight of vehicles such as automobiles and the reduction in the size of engine rooms. For this reason, the air conditioner hose for a vehicle is no exception, and it is required to be flexible in a narrow space and without being in contact with peripheral devices. On the other hand, in the conventional straight hose, it is necessary to forcibly bend and attach it, and the work at the time of attachment becomes difficult, and in some cases, it cannot be attached due to contact with peripheral devices.

  Therefore, in order to meet these requirements, proposals have been made to mold and vulcanize the hose in a bent state. However, in order to manufacture a bent tube of a resin-rubber composite hose, usually, a resin and rubber are simultaneously or stepwise stacked around an elongated rubber or resin mandrel to form an inner tube. A reinforcing layer in which polyester yarn or the like is knitted and wound is provided on the surface of the inner tube, and the outer rubber is extrusion coated from above the reinforcing layer. In this case, when the hose is a straight straight pipe, vulcanization is performed as it is, and then a mandrel is extracted to obtain a vulcanized resin-rubber composite hose.

  On the other hand, when the hose is a bent pipe, the long straight mandrel is extracted, and then the unvulcanized hose is cut to a short length to obtain the metal mandrel having a predetermined bent shape. Insert into an unvulcanized hose and vulcanize, or pull out a straight long mandrel and cut the dimensions, then reinsert a short resin or rubber mandrel into this unvulcanized short hose, or a long mandrel The bent hose is manufactured by either of the following methods: cutting the dimensions while inserting and vulcanizing the outer frame with a bent shape.

  The former manufacturing method is not particularly problematic when the inner tube is made of rubber, and is a widely adopted method. However, when a thermoplastic resin is used for the innermost tube, a bent mandrel is inserted. At this time, the interface between the resin and the rubber is peeled off, or the surface of the inner tube resin is scratched during the operation of removing the metal mandrel after molding vulcanization. Moreover, in the latter manufacturing method, since the outer layer rubber is unvulcanized, it comes into contact with the outer frame at the time of vulcanization and causes damage to the outer rubber.

  Moreover, in the construction method in which the size is cut while the long mandrel is inserted, the mandrel cannot be reused, resulting in a cost increase. Further, in the case of bending by an outer frame, it is difficult to produce an outer frame having a complicated three-dimensional shape and the cost is great, so it is not suitable for practical use.

  Therefore, a method for manufacturing a bent hose as described below has been proposed. A method of manufacturing such a bent hose according to the conventional example will be described below with reference to FIGS. FIG. 7 is a partial cutaway view of a straight unvulcanized composite hose before molding according to a conventional example, and FIG. 8 is an explanatory view of extrusion of a three-layer hose showing an example according to another conventional example.

  In FIG. 7, this composite bent hose is manufactured by a two-layer spiral structure in which a mandrel 20 made of rubber or resin is sandwiched from the inside with an inner surface resin layer 21, an inner tube unvulcanized rubber layer 22, and an intermediate rubber layer 24. A first step of forming the unvulcanized composite hose in a straight state by sequentially laminating the reinforcing layers 23 and 25 and the outer unvulcanized rubber layer 26, and forming the unvulcanized composite hose in a straight state; A second step of applying a resin coating 27 having a property that the softening point is higher than the temperature at the time of molding vulcanization on the vulcanized rubber layer 26, and a third step of preheating the inner resin layer 21 in a temperature range in which elastic deformation occurs. And have.

  At the same time, subsequently, a fourth step of loading the preheated unvulcanized composite hose into a mold preheated to around the vulcanization temperature, a fifth step of molding and vulcanizing under predetermined vulcanization conditions, and an inner surface resin layer 21 A sixth step of removing the resin coating 27 and the mandrel 20 in a temperature range in which the inner surface resin layer 21 exhibits elastic deformation, and a purpose of cooling while cooling to room temperature. And an eighth step that is loaded in a mold under the molding conditions (see Patent Document 1).

  However, such a method for manufacturing a composite bent hose according to the conventional example has a problem in that it requires a complicated and multi-step process, resulting in a large labor-saving manufacturing cost for process management. Therefore, in the manufacturing method of the rubber-resin laminated bent hose according to another conventional example in FIG. The outer rubbers are respectively extruded by the third extruder 33 and are laminated on the outer periphery of the core 30 in this order.

  The stacked hoses are cut to a predetermined length and pre-vulcanized. Then, the core 30 is extracted from the pre-cured hose, and the hose is inserted into a vulcanizing mandrel provided with a desired bend, and this vulcanization is performed with the vulcanizing mandrel attached (see Patent Document 2). ).

  However, the method of manufacturing the resin-rubber composite bent hose according to the conventional example is because the vulcanized mandrel is directly inserted into the unvulcanized hose from which the core 30 has been removed, and the main vulcanization is performed. Therefore, it is not suitable for manufacturing a composite hose having a complicated three-dimensional shape.

On the other hand, the manufacturing method of the bending hose which concerns on the following conventional examples using the shape memory alloy for the shaping | molding mandrel is proposed. That is, this bending hose manufacturing method includes a molding step of forming an unvulcanized rubber hose from compounded rubber, and a predetermined temperature at a predetermined temperature or higher that is formed by spirally winding a flat or wire shape memory alloy into a cylindrical shape. An insertion step of inserting a mandrel having a shape memorized in a curved shape having a diameter into the unvulcanized rubber hose as an approximately straight shape whose outer diameter is smaller than the inner diameter of the unvulcanized rubber hose; It consists of a vulcanization process in which the unvulcanized rubber hose is shaped into a predetermined bent shape and vulcanized, and a process of pulling out the mandrel from the bent hose after vulcanization by heating to a temperature higher than that and deforming the shape memory. (See Patent Document 3).
JP 11-192668 A JP 2000-289121 A JP-A-5-147124

  However, the manufacturing method of the bent hose according to the conventional example must use an expensive shape memory alloy, and the shape memory is used for manufacturing a rubber hose having a complicated three-dimensional bent shape or a large curvature. There has been a problem in that a satisfactory bent shape cannot be obtained with accuracy by shape deformation with an alloy.

  Accordingly, an object of the present invention is to provide a high-quality resin-rubber composite bent hose having a complicated three-dimensional shape and having no scratch on the inner surface, a bent hose molding mandrel that can be manufactured with high accuracy at low cost, and the use thereof. It is to provide a bent hose forming method.

  The bent hose molding mandrel according to claim 1 of the present invention employs a resin-rubber composite bent hose in which a plurality of rubber layers and a reinforcing layer interposed between the plurality of rubber layers are coated on the outside of the resin tube. A bent hose molding mandrel used for molding is characterized by comprising a flexible tube and a rubber layer coated on the outer periphery of the flexible tube.

  The bent hose molding mandrel according to claim 2 of the present invention employs the bent hose molding mandrel according to claim 1, wherein the flexible tube is made of a metal spring, a heat resistant resin spring, or an interface. It is a lock tube.

  The bending hose molding mandrel according to claim 3 of the present invention employs the bending hose molding mandrel according to claim 1 or 2, wherein the heat resistant resin spring is a composite of super engineering resin and reinforcing material. It consists of a general-purpose engineering resin combined with a super engineering resin or a reinforcing material.

  The means adopted by the bent hose forming mandrel according to claim 4 of the present invention is the bent hose forming mandrel according to any one of claims 1 to 3, wherein the rubber layer is made of ethylene-propylene. -It is characterized by comprising diene copolymer rubber (EPDM), fluorine rubber, silicone rubber, butyl rubber, acrylic rubber or ethylene-propylene rubber (EPM).

  The resin-rubber composite bent hose manufacturing method according to claim 5 of the present invention employs a resin in which a plurality of rubber layers and a reinforcing layer interposed between the plurality of rubber layers are coated on the outside of the resin tube. In the production of a rubber composite bent hose, the unvulcanized resin-rubber composite hose is cut to a predetermined length, and then inside the resin tube, according to any one of claims 1 to 4. A bent hose is manufactured by inserting a mandrel for forming a bent hose, and further inserting a mold mandrel into the mandrel for forming a bent hose, followed by vulcanization.

  The method adopted by the method for producing a resin-rubber composite bent hose according to claim 6 of the present invention is the method for producing a resin-rubber composite bent hose according to claim 5, wherein the unvulcanized resin-rubber composite hose. Is pre-vulcanized before being cut into a predetermined length.

  The resin-rubber composite bent hose manufacturing method according to claim 7 of the present invention employs a resin coated with a plurality of rubber layers and a reinforcing layer interposed between the plurality of rubber layers on the outside of the resin tube. In the production of a rubber composite bent hose, the unvulcanized resin-rubber composite hose is cut into a predetermined length, and then bent inside the resin tube according to any one of claims 1 to 4. By inserting a hose molding mandrel and pre-vulcanizing in a straight state to heat shrink the reinforcing layer, then inserting a mold mandrel into the bent hose molding mandrel and vulcanizing this A bent hose is manufactured.

  According to the bending hose molding mandrel according to claim 1 of the present invention, molding of a resin-rubber composite bending hose in which a plurality of rubber layers and a reinforcing layer interposed between the plurality of rubber layers are coated on the outside of the resin tube. Bending hose molding mandrel used in the construction of a flexible tube and a rubber layer coated on the outer periphery of the flexible tube. Can provide an inexpensive molding mandrel.

  Further, according to the bent hose molding mandrel according to claim 2 of the present invention, the flexible tube is a metal spring, a heat resistant resin spring or an interlock tube, and thus has a complicated three-dimensional shape. It is possible to provide a mandrel for forming a bent hose capable of manufacturing a resin-rubber composite bent hose with high accuracy at low cost by utilizing a commercially available product.

  Furthermore, according to the bent hose molding mandrel according to claim 3 of the present invention, the heat-resistant resin spring is made of a super engineering resin, a super engineering resin combined with a reinforcing material, or a general engineering resin combined with a reinforcing material. Therefore, a flexible tube having an arbitrary shape can be formed, and the application range of the bent hose molding mandrel is expanded.

  Furthermore, according to the bent hose molding mandrel according to claim 4 of the present invention, the rubber layer comprises ethylene-propylene-diene copolymer rubber (EPDM), fluorine rubber, silicone rubber, butyl rubber, acrylic rubber, or Since it is made of ethylene-propylene rubber (EPM), it is possible to provide a mandrel for forming a bent hose capable of manufacturing a high-quality resin-rubber composite bent hose having no scratches on the inner surface with high accuracy.

  On the other hand, according to the method for manufacturing a resin-rubber composite bent hose according to claim 5 of the present invention, the unvulcanized resin-rubber composite hose is cut into a predetermined length, and then the bent hose molding mandrel is inserted. Furthermore, since a bent hose is manufactured by inserting a mold mandrel into this bent hose molding mandrel and then vulcanizing, a resin-rubber composite bent hose having a complicated three-dimensional shape can be made inexpensively. Manufacturable.

  According to the method for producing a resin-rubber composite bent hose according to claim 6 of the present invention, the rubber layer is pre-vulcanized before the unvulcanized resin-rubber composite hose is cut into a predetermined length. The rubber elasticity is imparted to a certain degree to the inner surface of the resin tube, which contributes to preventing damage when the bent hose molding mandrel is inserted.

  Furthermore, according to the manufacturing method of the resin-rubber composite bent hose according to claim 7 of the present invention, the unvulcanized resin-rubber composite hose is cut to a predetermined length, and then the bent hose molding mandrel is inserted. Then, the heat-shrinkage of the reinforcing layer is performed by pre-vulcanization in a straight state, and then a bent hose is manufactured by inserting a mold mandrel into the bent hose molding mandrel and performing main vulcanization. A gap between the resin tube and the bent hose molding mandrel is eliminated, and a high-quality resin-rubber composite bent hose can be manufactured without causing defects such as wrinkles and bumps on the inner surface of the resin tube.

  First, an embodiment according to the bent hose molding mandrel of the present invention will be described with reference to the attached FIGS. FIG. 1 is a longitudinal sectional view of a bent hose molding mandrel according to an embodiment of the present invention, and FIG. 2 is a transverse sectional view of a bent hose molding mandrel according to an embodiment of the present invention.

  The bending hose molding mandrel according to the present invention is used for molding a resin-rubber compound bending hose in which a plurality of rubber layers and a reinforcing layer interposed between the plurality of rubber layers are coated on the outside of a resin tube as described later. It is a bent mandrel for forming hose. The bent hose molding mandrel 1 is composed of a flexible tube 2 and a rubber layer 3 coated on the outer periphery of the flexible tube 2.

  The flexible tube 2 has heat resistance during vulcanization and imparts a free shape to the unvulcanized resin-rubber composite hose along the shape of the mold mandrel having a desired three-dimensional shape. Therefore, it is made of a flexible member having a hollow portion 2a such as a metal spring, a heat resistant resin spring or an interlock tube. The outer circumference of the flexible tube 2 is configured by covering a rubber layer 3. This is because by covering the flexible tube 2 with the rubber layer 3, it is possible to prevent the outer shape of the flexible tube 2 from being applied to the inner surface of the resin tube or from being damaged.

  As the metal spring constituting the flexible tube 2, a commercial product using spring steel can be used. Moreover, the said interlock tube can use various sizes as a commercial item (for example, product made from Hagitec Co., Ltd.). Further, the heat-resistant resin spring constituting the flexible tube 2 is preferably made of a super engineering resin, a super engineering resin combined with a reinforcing material, or a general-purpose engineering resin combined with a reinforcing material. The super engineering resin is generally a thermoplastic resin that has higher heat resistance than general-purpose engineering resins and can be used for a long time even at a high temperature of 150 ° C. or higher.

  Such super engineering resins include polyphenylene sulfide (PPS), polyimide (PI), polyetherimide (PEI), polyarylate (PAR), polysulfone (PSF), polyethersulfone (PES), polyetherether. Examples include ketone (PEEK), liquid crystal polymer (LCP), and polytetrafluoroethylene (PTFE). The super engineering resin combined with a reinforcing material refers to a resin (FRP) in which a filler such as glass fiber or carbon fiber is mixed to reinforce such a resin.

  Furthermore, the general-purpose engineering resin is a general term for thermoplastic resins having heat resistance of 100 ° C. or higher, strength of 49 MPa or higher, and flexural modulus of 2.4 GPa or higher. General-purpose engineering resins include polyamide (PA), polyacetal (POM), polycarbonate (PC), modified ponyphenylene ether (m-PPE), polybutylene terephthalate (PBT), ultrahigh molecular weight polyethylene (UHPE), and reinforcing material In the same manner as described above, the super engineering resin composited with is a resin reinforced with such a resin (FRP) mixed with fillers such as glass fiber and carbon fiber.

  The flexible tube 2 composed of a metal spring, a heat-resistant resin spring or an interlock tube constituting the flexible tube 2 as described above is a bent shape of a resin-rubber composite bent hose to be manufactured. What is necessary is just to select the material of a suitable material and a dimension suitably according to a dimension.

  As the rubber layer 3, ethylene-propylene-diene copolymer rubber (EPDM), fluorine rubber, silicone rubber, butyl rubber, acrylic rubber, ethylene-propylene rubber (EPM), or the like is used. It is preferable from the viewpoint of having flexibility corresponding to the above and heat resistance during vulcanization. The thickness of the rubber layer 3 is not particularly limited, and an appropriate thickness dimension may be selected according to the inner diameter of the resin-rubber composite bent hose to be manufactured and the outer diameter of the mold mandrel.

  Next, Embodiment 1 according to the method for producing a resin-rubber composite bent hose of the present invention will be described below with reference to the attached FIGS. FIG. 3 is a process diagram for explaining a method for manufacturing a resin-rubber composite bent hose according to Embodiment 1 of the present invention, and FIG. 4 is a method for manufacturing a resin-rubber composite bent hose according to Embodiment 1 of the present invention. FIG. 2 shows a partially cutaway perspective view of an unvulcanized resin-rubber composite hose.

  In FIG. 3, the method for manufacturing the resin-rubber composite bent hose according to Embodiment 1 of the present invention is first because the unvulcanized resin-rubber composite hose 11 has a length of about 50 to 100 m normally. This is dimensionally cut 12 to a predetermined length of about 0.5 to 2 m according to the product length.

  Here, as illustrated in FIG. 4, the unvulcanized resin-rubber composite hose 11 is provided on the outer side of the inner tube 5 provided with the inner rubber layer 5 b on the outer side of the resin tube 5 a and on the outer side of the inner tube 5. And the outer rubber layer 7 coated on the outer side of the fiber reinforcing layer 6. The rubber layer is not limited to the inner rubber layer 5b and the outer rubber layer 7, and may have an intermediate rubber layer between them, and may have a plurality of the fiber reinforcing layers 6.

  Then, the bent mandrel 1 for forming the bent hose according to the present invention described with reference to FIG. 1 is inserted 13 inside the cut unvulcanized resin-rubber composite hose 11 inside the resin tube 5a. A mold mandrel is inserted 14 into the hollow portion 2 a of the bent hose molding mandrel 1. Thereafter, the mixture is heated at a predetermined temperature for a predetermined time and vulcanized. After the cooling is completed, the mold mandrel is first extracted 16a, then the bent hose molding mandrel 1 is extracted 16b, and the production of the resin-rubber composite bent hose 17 is completed.

  Here, the unvulcanized resin-rubber composite hose 11 illustrated in FIG. 4 will be described in more detail. As the resin tube 5a, a polyamide resin is usually used frequently. As such a polyamide resin, PA6, PA66, a copolymer of PA6 and PA66, a copolymer of PA11, PA12, PA11 and PA12, a modified product, a blended product, and a blend of PA with an olefin are suitable.

  The rubber material of the inner rubber layer 5b is preferably butyl rubber (IIR). This is because this butyl rubber is a copolymer of isobutylene and isoprene, and has excellent heat resistance, cold resistance, weather resistance, chemical resistance, and flex crack resistance, and also has low gas permeability. The butyl rubber may be a halogenated butyl rubber such as chlorinated butyl rubber or brominated butyl rubber.

  The rubber material of the outer rubber layer 7 and the intermediate rubber layer is preferably butyl rubber or EPDM. This butyl rubber has the properties of extremely low gas permeability and low rebound resilience as described above, and is excellent in heat resistance and weather resistance. EPDM is similarly heat resistant, weather resistant, ozone resistant. It is because it is excellent in property. The heating temperature and heating time required for vulcanization of such a rubber layer are slightly different depending on the crosslinking characteristics of the rubber raw material used. In the case of the rubber material as described above, the heating temperature and the heating time are 40 at a temperature of around 160 ° C. Heating time of about a minute is required.

  Next, the fiber reinforcing layer 6 will be described. A plurality of reinforcing yarns are aligned and wound around the outer peripheral surface of the inner rubber layer 5b while being crossed and knitted. The reinforcing yarn is preferably formed by twisting a plurality of polyester yarns.

  Here, it is important that the clearance between the outer diameter of the bent hose molding mandrel 1 and the inner diameter of the unvulcanized resin-rubber composite bent hose 11 is about 0.2 to 0.5 mm in diameter. When the gap is less than 0.2 mm, it is difficult to insert the bent hose molding mandrel 1 into the unvulcanized resin-rubber composite bent hose 11, and when the gap exceeds 0.5 mm, the unvulcanized This is because even if the resin-rubber composite bent hose 11 is contracted by vulcanization, the desired inner diameter may not be reached.

  On the other hand, the mold mandrel is preferably made of a steel bar or a stainless steel bar, which has been given a desired three-dimensional shape in advance and has a chrome plated surface.

  Next, Embodiment 2 according to the method for producing a resin-rubber composite bent hose of the present invention will be described below with reference to FIG. FIG. 5 is a process diagram for explaining a method for manufacturing a resin-rubber composite bent hose according to Embodiment 2 of the present invention. The second embodiment of the present invention differs from the first embodiment in that the vulcanization method is different, and the other components are the same in configuration, so the same reference numerals are assigned to the same components as in the first embodiment. The differences will be described below.

  That is, in the method of manufacturing the resin-rubber composite bent hose according to the second embodiment of the present invention, as shown in FIG. To do. The preliminary vulcanization 15a may be heated to a temperature of about 160 ° C. for 5 minutes. This is because by performing such preliminary vulcanization 15a, a certain degree of elasticity is imparted to the rubber layers 5b and 7 and it is possible to contribute to prevention of damage by the mandrel insertion 13 for forming a bent hose.

  Next, a third embodiment of the method for producing a resin-rubber composite bent hose of the present invention will be described below with reference to the attached FIG. FIG. 6 is a process diagram for explaining a method for manufacturing a resin-rubber composite bent hose according to Embodiment 3 of the present invention. It should be noted that the third embodiment of the present invention differs from the first embodiment in that the vulcanization method is different and the other configuration is the same. Therefore, the same reference numerals are assigned to the same components as in the first embodiment. The differences will be described below.

  That is, the method for manufacturing a resin-rubber composite bent hose according to Embodiment 3 of the present invention, as shown in FIG. 6, prior to inserting a mold mandrel 14 into an unvulcanized resin-rubber composite hose, Sulfur 15a is produced. The preliminary vulcanization 15a may be heated to a temperature of about 160 ° C. for 5 minutes. This is because by performing such preliminary vulcanization, a certain degree of elasticity is imparted to the rubber layer, which can contribute to preventing damage due to the mold mandrel insertion 14.

  As mentioned above, according to the manufacturing method of the bending hose molding mandrel of the present invention and the resin-rubber composite bending hose using the same, the flexible tube and the rubber layer coated on the outer periphery of the flexible tube are configured. It is a mandrel for bending bent hose, and it is a method of manufacturing a resin-rubber compound bent hose using this bent hose forming mandrel, so it can be flexibly adapted to bent hoses with complicated three-dimensional shapes. A molding mandrel and an inexpensive and simple resin-rubber composite bent hose using the same can be provided.

<Example-1>
4 has an outer diameter of 19.0 mm in which a butyl rubber layer, a fiber reinforcing layer, and an outer rubber layer made of EPDM are sequentially formed on the outside of a PA6 tube having an inner diameter of 12.0 mm and a thickness of 0.15 mm. The unvulcanized resin-rubber composite hose was first dimensionally cut 12 to 1.5 m according to the process of FIG. Next, a bending hose molding mandrel using a metal spring as a flexible tube and having an outer diameter of 11.9 mm and an inner diameter of 9.4 mm is inserted 13 inside the PA6 tube of the cut composite rubber hose.

  Next, a mold mandrel having an outer diameter of 8.0 mm is inserted 14 into the hollow portion of the bent hose molding mandrel, and is loaded in a vulcanizing can as it is, and vulcanized by holding at a temperature of 160 ° C. for 40 minutes. . After cooling, this is taken out and the mold mandrel is extracted 16a, and then the bent hose molding mandrel is extracted 16b. As a result, a bent hose product is obtained in which the inner surface of the PA 6 is not damaged and is shaped according to the shape of the molding mandrel. It was. When the bent hose 17 was divided along the axial direction and the inner surface was visually observed, no damage by the mandrel was observed.

<Example-2>
4 has an outer diameter of 19.0 mm in which a butyl rubber layer, a fiber reinforcing layer, and an outer rubber layer made of EPDM are sequentially formed on the outside of a PA6 tube having an inner diameter of 12.2 mm and a thickness of 0.15 mm. The unvulcanized resin-rubber composite hose was first dimensionally cut 12 in accordance with the process shown in FIG. 6 to prepare 10 unvulcanized resin-rubber composite hoses having a length of 1.5 m.

  Next, a bending hose molding mandrel having an outer diameter of 11.9 mm and an inner diameter of 9.4 mm using a metal spring as a flexible tube was inserted 13 inside the PA6 tube of the cut composite rubber hose. Then, the composite rubber hose was loaded into a heating furnace while being kept in a straight state, and kept at a temperature of 160 ° C. for 5 minutes for preliminary vulcanization 15a. Next, a mold mandrel having an outer diameter of 8.0 mm was inserted 14 into the hollow portion of the bent hose molding mandrel, and loaded in a vulcanizing can as it was, and vulcanized 15 by holding at a temperature of 160 ° C. for 35 minutes. .

  After cooling, this is taken out, the mold mandrel is extracted 16a, and then the bent hose molding mandrel is extracted 16b. As a result, ten bent hose products 17 in which the three-dimensional shape of the molding mandrel is formed are formed. was gotten. The bent hose 17 was divided into a whole number along the axial direction, and the inner surface of the PA 6 was visually observed.

<Example-3>
Example 10 except that the same unvulcanized resin-rubber composite hose as in Example 1 was used, and a bent hose molding mandrel using an interlock tube as the flexible tube was used. Exactly the same treatment as 3 was performed. When the obtained bent hose was divided along the axial direction and the inner surface was visually observed, no damage such as wrinkles, humps, or scratches was observed in all ten.

<Comparative Example-1>
Using an unvulcanized resin-rubber composite hose 11 similar to that in Example 1, a mold mandrel having an outer diameter of 11.9 mm was directly inserted inside the PA6 tube without using the bent hose molding mandrel. Except that, the same process as in Example-1 was performed. When the obtained bent hose was divided along the axial direction and the inner surface was visually observed, wrinkles occurred at the bent portion of the inner surface of the PA6 tube.

<Comparative Example-2>
Using 10 unvulcanized resin-rubber composite hoses similar to Example-3, a mold mandrel having an outer diameter of 11.9 mm was directly inserted inside the PA6 tube without using the bent hose molding mandrel. Except for this, the same process as in Example-3 was performed. When the total number of the obtained bent hoses was divided along the axial direction and the inner surface was visually observed, two of the ten bent hoses were wrinkled at the bent portion of the inner surface of the PA6 tube.

  As described above, the bending hose molding mandrel according to the present invention is a bending used for molding a resin-rubber composite bending hose in which a plurality of rubber layers and a reinforcing layer interposed between the plurality of rubber layers are coated on the outside of the resin tube. A hose molding mandrel comprising a flexible tube having a hollow portion inside and a rubber layer coated on the outer periphery of the flexible tube. By inserting a mold mandrel having a three-dimensional shape, it is possible to provide an inexpensive molding mandrel that can be freely adapted to a bent hose having a complicated shape.

  In the method for producing a resin-rubber composite bent hose according to the present invention, the unvulcanized resin-rubber composite hose is cut into a predetermined length, and then the bent hose molding mandrel is inserted. Since a bending hose is manufactured by inserting a mold mandrel into a molding mandrel and then vulcanizing it, a resin-rubber composite bending hose having a complicated three-dimensional shape can be manufactured at a low cost.

  According to the present invention, the bending hose molding mandrel and the resin-rubber composite bending hose are manufactured by a method in which a resin tube is coated with a plurality of rubber layers and a reinforcing layer interposed between the plurality of rubber layers. -Although preferably used in a method for manufacturing a rubber composite bent hose, the present invention is not limited to such a hose configuration. For example, a resin-rubber composite in which a thin rubber layer is provided inside the resin tube to prevent damage. Needless to say, the method can be applied to a method of manufacturing a bent hose.

It is a longitudinal section of a bent hose molding mandrel according to an embodiment of the present invention. It is a cross-sectional view of a bent hose molding mandrel according to an embodiment of the present invention. It is process drawing for demonstrating the manufacturing method of the resin-rubber compound bending hose which concerns on Embodiment 1 of this invention. The partially cutaway perspective view of the unvulcanized resin-rubber composite hose in the manufacturing method of the resin-rubber composite bend hose according to Embodiment 1 of the present invention is shown. It is process drawing for demonstrating the manufacturing method of the resin-rubber compound bending hose which concerns on Embodiment 2 of this invention. It is process drawing for demonstrating the manufacturing method of the resin-rubber compound bending hose which concerns on Embodiment 3 of this invention. It is a partial cutaway view of a straight unvulcanized composite hose before molding according to a conventional example. It is explanatory drawing of extrusion of the 3 layer hose which shows the Example which concerns on another prior art example.

Explanation of symbols

1: Mandrel for molding bent hose,
2: Flexible tube, 2a: Hollow part,
3: Rubber layer,
5: Inner tube, 5a: Resin tube, 5b: Internal rubber layer,
6: reinforcement layer (fiber reinforcement layer), 7: outer rubber layer 11: unvulcanized resin-rubber composite hose, 12: dimension cut,
13: Insert a mandrel for bending hose molding, 14: Insert a mold mandrel,
15: vulcanization, 15a: preliminary vulcanization,
16a: Die mandrel sampling, 16b: Bending hose molding mandrel sampling,
17: Resin-rubber composite bent hose

Claims (7)

  A bending hose molding mandrel used for molding a resin-rubber composite bending hose, in which a plurality of rubber layers and a reinforcing layer interposed between the plurality of rubber layers are coated on the outside of the resin tube, A bent mandrel for forming a bent hose comprising a rubber layer coated on the outer periphery of the flexible tube.   2. The bent hose molding mandrel according to claim 1, wherein the flexible tube is a metal spring, a heat resistant resin spring, or an interlock tube.   The bent heat hose molding mandrel according to claim 1 or 2, wherein the heat resistant resin spring is made of a super engineering resin, a super engineering resin combined with a reinforcing material, or a general-purpose engineering resin combined with a reinforcing material.   The rubber layer is made of ethylene-propylene-diene copolymer rubber (EPDM), fluorine rubber, silicone rubber, butyl rubber, acrylic rubber, or ethylene-propylene rubber (EPM). A mandrel for forming a bent hose according to any one of the items.   In the manufacture of a resin-rubber composite bent hose in which a plurality of rubber layers and a reinforcing layer interposed between the plurality of rubber layers are coated on the outside of the resin tube, the unvulcanized resin-rubber composite hose is cut to a predetermined length. After that, the bent hose molding mandrel according to any one of claims 1 to 4 is inserted inside the resin tube, and a mold mandrel is further inserted into the bent hose molding mandrel. Then, a bent hose is manufactured by subsequent vulcanization, and a method for manufacturing a resin-rubber composite bent hose.   6. The method for producing a resin-rubber composite bent hose according to claim 5, wherein the unvulcanized resin-rubber composite hose is pre-vulcanized before cutting into a predetermined length.   In the manufacture of a resin-rubber composite bent hose in which a plurality of rubber layers and a reinforcing layer interposed between the plurality of rubber layers are coated on the outside of the resin tube, the unvulcanized resin-rubber composite hose is cut to a predetermined length. Then, the bending hose molding mandrel according to any one of claims 1 to 4 is inserted inside the resin tube and pre-vulcanized in a straight state to heat the reinforcing layer. The method for producing a resin-rubber composite bent hose according to claim 1, wherein the bent hose is manufactured by shrinking and then inserting a mold mandrel into the bent hose molding mandrel and vulcanizing the mandrel.

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