CN101270836A - Fuel hose and injection hose - Google Patents

Abstract

A fuel hose and an infusing hose are provided. A fuel hose includes a hard resin barrier layer located in middle of the radial direction of the fuel hose and penetrating an axial end of the fuel hose, therefore enough sealing performance obtained when clamping the hose on the tubing by a hose clamp. A fuel hose (10) for a fuel pipeline in an motor vehicle has a multilayer structure including a resin barrier layer (12) having low permeability to fuel, an outer rubber layer (14) laminated on an outer side of the barrier layer (12) and an inner rubber layer (16) laminated on an inner side of the barrier layer (12) and defining an inner surface layer of the fuel hose (10). The multilayer structure is formed throughout an entire length of the fuel hose (10). A rubber hardness of the inner rubber layer (16) is higher than a rubber hardness of the outer rubber layer (14).

Description

Fuel hose and injection hose

Technical field

The present invention relates to a kind of fuel hose, in the middle of it is included in radially or have low fuel infiltrative resin blocking layer and a transfer the fuel on its cross section, this fuel hose for example is used for fuel is delivered to the injection hose (filler hose) that the resin rubber composite of fuel tank is made.

Background technique

Be applicable to that the fuel that will be expelled to fuel inlet is transported in the injection hose of the fuel tank in the automobile, use traditionally a kind of mixture by acrylonitrile butadiene rubber and PVC (the NBR/PVC mixture, NBR+PVC) or the typical rubber hose made of other analogs.The rubber hose of this NBR+PVC has high shock absorption, is easy to assembling, and has good relatively low fuel (gasoline) permeability.

Yet this typical rubber hose can not satisfy recently fully to the infiltrative more and more higher requirement of low fuel.

As the countermeasure of this situation, develop and used a kind of injection hose as rubber resin composite flexible pipe.This injection hose comprises resin layer, and this resin layer is covered in the inboard of outer rubber layer as interior surface layers.This resin layer has the good hypotonicity (permeability resistance) to fuel, and defines the blocking layer.

But because resin is a kind of material harder than rubber, this resin blocking layer is harder.Therefore, in the injection hose that comprises the resin blocking layer, this resin blocking layer is covered in the inboard of outer rubber layer up to the flexible pipe axial end, when this injection hose docks with pipe arrangement, because this pipe arrangement and define bad connection between the resin blocking layer of flexible pipe internal surface causes the sealability deficiency.

And, since limit the blocking layer of internal surface of injection hose hard and when being assemblied in this injection hose on the pipe arrangement resistance to deformation power big, need very big power to be assemblied in fuel hose on the pipe arrangement or fill in pipe arrangement.This just causes a problem, has promptly damaged the easiness that connects injection hose and pipe arrangement.

For the purpose that addresses this problem, open in thepatent documentation 1 below of injection hose as shown in Figure 4.

Among the figure, the injection hose ofreference character 200 expression rubber resin composites,reference character 202 expression outer rubber layers,reference character 204 expressions are covered in the resin blocking layer of the inboard ofouter rubber layer 202 as interior surface layers.

Ininjection hose 200, will with end thatmetal pipe arrangement 206 is connected on do not have coveringresin blocking layer 204, the internal surface ofouter rubber layer 202 exposes, to concern the elasticity assembling withpipe arrangement 206 with what directly contact.

And, penetrate into for fear of fuel between the internal surface of exposure ofouter rubber layer 202 and thepipe arrangement 206 and and pass the not problem of the end of theouter rubber layer 202 on coveringresin blocking layer 204 to exosmosis in internal flow, ininjection hose 200, formannular groove portion 208 in the end onresin blocking layer 204, in annular groove portion, install by for example fluorine rubber materials such as (FKM) and make and have an infiltrative cyclicspring sealing component 210 of lowfuel.Injection hose 200 is mounted on thepipe arrangement 206 so that the internal surface offlexible sealing component 210 flexibly contacts withpipe arrangement 206.

Typical injection hose shown in Fig. 4 connects by thehose clip 214 with screw threads for fastening mechanism and is fixed on thepipe arrangement 206.

Simultaneously, among Fig. 4,reference character 212 is illustrated in the lug boss (heave portion) of the front end upper edge radially outward directional ring ofpipe arrangement 206 toprojection.Injection hose 200 is fixed on thepipe arrangement 206 by the outer circumferential face thathose clip 214 radially inwardly is anchored on an end that is not coated withresin blocking layer 204 ofouter rubber layer 202.

Fig. 5 shows the structure ofhose clip 214 especially.

As shown in the figure,hose clip 214 has themetal restraint zone 230 that exists with the band and the form offastening structure 234.

Restraint zone 230 comprises an end 230A and the other end 230B.One end 230A is formed with the circumferential equal angles slit-shaped slot that is used to receive screw thread, slit-shaped thread groove or slit 240 atinterval.Restraint zone 230 is rolled into annular as follows, promptly be threaded an end 230A ofgroove 240 and the outside of the other end 230B and overlap, and screw threads forfastening mechanism 234 is fixed on the 230B of the other end.

Screw threads forfastening mechanism 234 comprises: thehousing 236 that is fixed in the other end 230B; With external threaded 238, it comprises the double-screw bolt that is received in rotationally in the housing 236.The screw thread of external threaded 238 cooperates withaforementioned slots 240 and engages.

Under the situation ofhose clip 214, rotation along with external threaded 238, make an end 230A along the circumferential mobile (see figure 5) counterclockwise of the other end 230B by the screw rod feeding mechanism,restraint zone 230 is along the end of diameter contraction withfastening injection hose 200, particularly, the outer rubber layer as shown in Figure 4 202 on thepipe arrangement 206.

In theinjection hose 200 shown in Figure 4, on the end ofinjection hose 200 not stacked resin blocking layer 204.Therefore, wheninjection hose 200 is assembled on thepipe arrangement 206, does not act on very big resistance, thereby can injectionhose 200 easily be assemblied on thepipe arrangement 206 with less power fromresin blocking layer 204.

And this end atinjection hose 200 does not formresin blocking layer 204, and the elasticity internal surface ofouter rubber layer 202 directly contacts withpipe arrangement 206, thereby has excellent sealing performance between the auxiliary section ofpipe arrangement 206 andinjection hose 200.

Incidentally, because injection hose must be set to not disturb with peripheral components and assembly, so injection hose typically has predetermined curve shape.

Typical rubber hose with this curve shape is produced in disclosed mode in the following patent documentation 2.Form the rubber hose main body of long straight tube-like by extruding, and this rubber hose is cut into the straighttube-type rubber hose 216 (with reference to figure 6) of predetermined length with obtain not cure (or semi-cure).Straighttube-type rubber hose 216 is assembled on themetal core 218 with predetermined curve shape, to be deformed into curve shape.This crooked tubulartype rubber hose 216 cures by the heating predetermined amount of time under situation about being mounted on the plug 218.When sulfuration was finished, theflexible pipe 220 of curved shape was taken off fromplug 218, had obtained theflexible pipe 220 as the curve shape of finished product like this.

Yet, under the situation of the injection hose shown in Fig. 4 200, can not adopt such production method.In theinjection hose 200 shown in Figure 4, at first, only formouter rubber layer 202, then, on the internal surface ofouter rubber layer 202, formresin blocking layer 204, make it to comply with the shape of the internal surface ofouter rubber layer 202 by injection moulding.

In orderresin blocking layer 204 to be configured as comply with the inner surface configuration ofouter rubber layer 202, can use electrostatic spray.

Use electrostatic spraying as follows: injection nozzle is inserted in the injection hose, particularly, be inserted in theouter rubber layer 202, from this injection nozzle toner is ejected on the internal surface ofouter rubber layer 202 then, thereby the internal surface ofouter rubber layer 202 is by electrostatic spraying or be coated with toner.

In electrostatic spray process, form resin film in the following way, promptly, from the electronegative or positively charged toner (normally electronegative toner) of injection nozzle ejection, toner flies to and is attached to the internal surface ofouter rubber layer 202 owing to the effect of the counterelectrode (positive electrode) of electrostatic field.

In the step of this electrostatic spraying,, carry out more than an electrostatic spraying of taking turns usually in order to formresin blocking layer 204 with expectation thickness or wall thickness.

Particularly, after toner was attached on the internal surface ofouter rubber layer 202, toner is melted by heating to be cooled off then to form resin film.Then, further other toner is ejected into resin film and toner is attached to resin film by electrostatic spraying again, thereby and make this other toner melt then by heating cooling forms another resin film.In this mode, repeat the electrostatic spraying circulation has the expectation wall thickness up to formationresin blocking layer 204.

In this case, whole process step is as described below.

At first, formouter rubber layer 202 by injection moulding.Then,outer rubber layer 202 is carried out pretreatment dry and washing (wash), and then dry.Subsequently, by electrostatic spraying toner is attached to the internal surface of outer rubber layer 202.Toner on this internal surface is melted by heating to be cooled off then to form resin film.After this, carry out second taking turns the toner electrostatic spraying, by the heating and melting toner, make toner cooling and caking again, thereby form another resin film on resin film, this circulation constantly repeats up to desired times to obtain to have the resin blockinglayer 204 of expectation wall thickness.After finishingresin blocking layer 204, the axial end of the cyclicspring sealing component 210 with anti-fuel permeability byouter rubber layer 202 is inserted in the flexible pipe and is placed in the precalculated position.

As mentioned above, Fig. 4 showsproduction injection hose 200 needs a lot of steps, and therefore, the cost of production ofinjection hose 200 must increase.

Therefore, inventor of the present invention designs and has proposed a kind of injection hose of rubber resin composite in prior art patent application (for example, Japanese patent application No.2006-89387), it has multi-layer structure, wherein, inner rubber layer is laminated in the inboard on resin blocking layer as interior surface layers.

Fig. 7 shows a specific embodiment of injection hose.Thereby the injection hose 246A of multi-layer structure is provided withresin blocking layer 244 has hypotonicity (barrier properties) to the fluid of carrying.Further, when injection hose 246A fit onpipe arrangement 206, resiliently deformable takes place in theinner rubber layer 242 that defines the injection hose 246A internal surface of rubber resin composite.In this process, the required power that is used for flexible pipe is loaded onto pipe arrangement can reduce.

And because injection hose 246A is connected inpipe arrangement 206 so thatinner rubber layer 242 is flexibly contacted withpipe arrangement 206, Jie Chu tightness is improved therebetween.

And, in the injection hose 246A of multi-layer structure, becauseresin blocking layer 244 can form the axial end that runs through injection hose 246A, then being used to shown in Fig. 4 provides the more expensive cyclicspring sealing component 210 of the anti-permeability of conveyance fluid to dispense.

In addition, in the injection hose 246A of multi-layer structure,resin blocking layer 244 can form the axial end that runs through injection hose 246A.This makes that the production method of flexible pipe 246A is identical with the method shown in Fig. 6.

Especially,inner rubber layer 242, resin blockinglayer 244 andouter rubber layer 202 can be laminated to each other forming the rubber hose main body of long straight tube-like by extrusion process, and this rubber hose main body is cut into the straighttube-type rubber hose.So far obtain unvulcanised or semivulcanized straighttube-type rubber hose.Then, this extrudate, promptly the straighttube-type rubber hose is assembled on the plug with predefined curved shape with distortion, when this is assemblied in strained tubular rubber flexible pipe on the plug by complete cure, just obtains having the injection hose 246A of curve shape.

This manufacture method makes the cost of production of injection hose 246A greatly reduce than before.

In addition, the part that matches with pipe arrangement of injection hose is designed to have and matches well the little internal diameter of external diameter of pipe, so that the connection that an end of injection hose is assembled on the pipe arrangement is fastening.Typically, the inner end diameter of injection hose than the about little 1mm of the external diameter of pipe arrangement to 2mm.That is to say that the end of injection hose has and is approximately the clamping allowance (clamping allowance) of 0.5mm to 1mm.

Typical flexible pipe has the end of single rubber layer.When the end of this typical case's flexible pipe is fastening byhose clip 214, by 230 pairs of restraint zones should typical case's hose end interior perimeter surface whole week upwards apply fastening force equably, allow the interior perimeter surface of the end of typical flexible pipe upwards advantageously closely to contact in whole week with the outer surface of pipe arrangement 206.Thereby guaranteed between hose end andpipe arrangement 206, to have enough sealabilities.

Yet, the problem below finding among the injection hose 246A that has rubber-resin-rubber layer structure shown in Figure 7.In injection hose 246A, the intermediate barrier layers of being made by hardenedresin 244 runs through the axial end of injection hose 246A.When injection hose 246A is assemblied on thepipe arrangement 206, the outer surface of injection hose 246A end is tightened in the radial contraction direction by the hose clip among similar Fig. 4 214, so that injection hose 246A is tightened on thepipe arrangement 206 with the relation folder (lock) that connects, disturbed by middleresin blocking layer 244 by the clamping force thathose clip 214 transmits, cause to obtain required enough sealabilities between the end of injection hose 246A and the pipe arrangement 26.

Then, inventor of the present invention has studied the cause of problem and following discovery has been arranged.

In thehose clip 214 of type shown in Figure 5, when external threaded 238 was rotated, an end 230A ofrestraint zone 230 was circumferentially moved along the other end 230B by the screw rod feeding mechanism, andrestraint zone 230 is radially tightened.

Along withrestraint zone 230 radially tightens, the end ofhose clip 214 grip both hose makes the interior perimeter surface of hose end closely contact withpipe arrangement 206 outer surfaces, thereby provide sealing between flexible pipe andpipe arrangement 206.

Yet, shown in Fig. 7 A, comprise in the situation of injection hose 246A of rubber resin composite on hardenedresin blocking layer 244 in the centre of thickness direction, whenrestraint zone 230 radially tightens end with fastening injection hose 246A, the interior perimeter surface ofinner rubber layer 242 frompipe arrangement 206 separately or radially outward part projection slightly, shown in the part zoomed-in view among Fig. 7 B, it has caused this regional seal performance deficiency.

It is considered to followingreason.In restraint zone 230 radially tightened process with the end of fastening injection hose 246A, the hardenedresin blocking layer 244 of the centre that is positioned at thickness direction of injection hose 246A had hindered fastening force fully to be delivered to inner rubber layer 242.And, during this period,resin blocking layer 244 is deformation resistance in the direction that radially tightens, the fastened of injection hose 246A end upwards radially do not tightened in whole week equably with 230 fastening zones, near the end 230B that is in stationary state ofrestraint zone 230 part distortion, thus radially outwards omit microprotrusion from pipe arrangement.As a result, near the sealability of the part the end 230B that is in stationary state ofrestraint zone 230 is partly impaired.

That is to say, because the repellence that is positioned at that theresin blocking layer 244 of the injection hose 246A in the middle of the thickness direction provided to the distortion that radially tightens direction, the end of injection hose 246A, especially injection hose 246A is upward fastened trends towards flat, annular with 230 fastening zones, therefore, distortion and distortion concentrate on the close part that is in the end 230B of stationary state of restraint zone 230.This is considered to the sealability that can cause damage.

[patent documentation 1] JP-A, 2002-54779

[patent documentation 2] JP-A, 11-90993

Under afore-mentioned, the purpose of this invention is to provide fuel hoses such as a kind of for example injection hose, this injection hose comprise on the whole length that is applied in fuel hose or flexible pipe radially or the neutral position on the thickness direction extend through the hardened resin blocking layer of the axial end of fuel hose, thereby when being clipped on the pipe arrangement, can provide enough sealabilities by hose clip.

Summary of the invention

According to the present invention, provide a kind of New-type fuel flexible pipe that is applicable to the fuel conduit in Motor Vehicle or the automobile.This fuel hose comprises multi-layer structure, and this multi-layer structure comprises the inner rubber layer that has the infiltrative resin of low fuel blocking layer, is laminated in the outer rubber layer on this outside, blocking layer and is laminated in this inboard, blocking layer and define the interior surface layers of fuel hose.This multi-layer structure is formed on the whole length of fuel hose.The rubber hardness of this inner rubber layer is higher or bigger than the hardness of outer rubber layer.This fuel hose is the flexible pipe that is applicable to conveying or transport fuel, and for example, injection hose, ventilation duct, exhaust tube, breathing pipe and purification pipe all are contained in wherein.

According to an aspect of the present invention, the rubber hardness of inner rubber layer is than high 10 degree or more of rubber hardness of outer rubber layer.

According to an aspect of the present invention, the rubber hardness of inner rubber layer is 70 degree or higher, and the rubber hardness of outer rubber layer is 75 degree or lower.

According to the present invention, also provide a kind of novel injection hose that is used for fuel is delivered to the fuel tank of Motor Vehicle or automobile.This injection hose comprises multi-layer structure, this multi-layer structure comprise have the infiltrative resin of low fuel blocking layer, be laminated in this blocking layer inboard and define injection hose interior surface layers inner rubber layer and be laminated in the outer rubber layer in this outside, blocking layer.Extend to another axial end from an axial end of injection hose and form this multi-layer structure.The rubber hardness of outer rubber layer is 75 degree or lower, and the rubber hardness of inner rubber layer is 70 degree or higher, and the rubber hardness of inner rubber layer is than high 10 degree or more of rubber hardness of outer rubber layer.

As mentioned above, the present invention relates to a kind of fuel hose that is applicable to the fuel channel in the automobile.This fuel hose comprise have the infiltrative resin of low fuel blocking layer, at the outer rubber layer in the outside, this blocking layer with at the inner rubber layer of the flexible pipe internal surface that acts as a fuel of inboard, blocking layer.A kind of multi-layer structure of this resin blocking layer, outer rubber layer and inner rubber layer are formed on the whole length of fuel hose.The rubber hardness of inner rubber layer is than the rubber hardness height of outer rubber layer, for example, and high 10 degree or more.And for example, the rubber hardness of inner rubber layer is 70 degree or higher, and the rubber hardness of outer rubber layer is 75 degree or lower.At this, rubber hardness is measured by A type (spring scales) hardness tester according to JIS K6253.

The invention still further relates to a kind of injection hose.This injection hose comprise have the infiltrative resin of low fuel blocking layer, the inboard, blocking layer as the inner rubber layer of injection hose internal surface with at the outer rubber layer in this outside, blocking layer.The multi-layer structure on resin blocking layer, outer rubber layer and inner rubber layer form a axial end from injection hose to another axial end.The rubber hardness of outer rubber layer is 75 degree or lower, and the rubber hardness of inner rubber layer is 70 degree or higher, and the rubber hardness of inner rubber layer is than high 10 degree or more of rubber hardness of outer rubber layer.At this, rubber hardness is measured by A type (spring scales) hardness tester according to JIS K6253 equally.

According to the present invention, when fuel hose or injection hose are assembled on the pipe arrangement, the end of flexible pipe is clamped by hose clip, under whole week makes progress even and required surface pressure, the interior perimeter surface of hose end can clamp with the outer surface of pipe arrangement each other in intimate contact mutually, has so just guaranteed the sealability of expectation.

In the present invention, because outer rubber layer is formed by the soft rubber material with low rubber hardness and high deformability, or this outer rubber layer can be formed by the material with low rubber hardness and high deformability, so outer rubber layer is advantageously followed the fastening action of hose clip and is out of shape, prevent the outer surface of this outer rubber layer produce distortion and be delivered to be positioned on the flexible pipe thickness direction or cross section in the middle of the hardened resin blocking layer and the inner rubber layer that passes to inboard, resin blocking layer by outer rubber layer.That is to say that because this outer rubber layer is followed the fastening action of hose clip and advantageously radially tightened, this outer rubber layer upwards is not offset in week or the mobile big degree of hose clip ground towing, thereby can be distorted hardly on inner rubber layer.

The result, it has allowed radially to tighten the inner rubber layer that is positioned at the middle resin blocking layer of flexible pipe thickness direction and is positioned at this inboard, resin blocking layer at the uniform fastening force that makes progress in whole week by hose clip, also making the interior perimeter surface of flexible pipe, also is that the interior perimeter surface of inner rubber layer circumferentially closely contacts along whole equably with the outer surface of pipe arrangement.

And, because inner rubber layer is formed by the rubber material higher than the rubber hardness of outer rubber layer, when the inner rubber layer quilt is fastening slightly, between the interior perimeter surface of the outer surface of pipe arrangement and inner rubber layer, can produce high surface pressure, thereby allow inner rubber layer upwards to tighten up pipe arrangement securely in whole week.

Thereby guaranteed high sealing performance desired between hose end and pipe arrangement.

At this, the rubber hardness of inner rubber layer is than high 10 degree or more of rubber hardness of outer rubber layer.Or can be than the rubber hardness of outer rubber layer high 10 degree or more of the rubber hardness of inner rubber layer.Rubber hardness relation in this way allow outer rubber layer enough soft, and inner rubber layer is enough hard.And the rubber hardness of inner rubber layer is 70 degree or higher, and the rubber hardness of outer rubber layer is 75 degree or lower.Perhaps, the rubber hardness of inner rubber layer can be 70 degree or higher, and the rubber hardness of outer rubber layer can be 75 degree or lower.It is too soft to have the inner rubber layer of rubber hardnesses that is lower than 70 degree, when by the fastening hose end of hose clip, may not can produce high surface pressure between the outer surface of the interior perimeter surface of inner rubber layer and pipe arrangement.Also have, the outer rubber layer with the rubber hardness that is higher than 75 degree is too hard, and when by the fastening hose end of hose clip, outer rubber layer may be pulled at all upward displacements or the mobile big degree of hose clip ground.

When hose end is fastening by a worm-gear type hose clip, trend towards taking place the seal defect that aforementioned phenomenon causes, this worm-gear type hose clamp has thread type retention mechanism and restraint zone as shown in Figure 5.Therefore, when being applied to by the fuel hose (for example, injection hose) of such clamp on pipe arrangement, the present invention has produced very big effect.

In the present invention, outer rubber layer is formed by the soft elastic rubber material with low rubber hardness and high deformability.Therefore, flexible pipe of the present invention is easy to handle and be easy to assembling.After assembling, its additional effect is the negative effect that this flexible pipe can be subjected to external component resonance such as motor for example hardly, and then, can keep in collision that this flexible pipe is as safe as a house to be without prejudice.

Now, describe the preferred embodiments of the present invention in detail below in conjunction with accompanying drawing.

Description of drawings

Fig. 1 shows the perspective view of injection hose according to an embodiment of the invention, and its part is dissectd;

Fig. 2 A is the global sections figure of the injection hose among Fig. 1;

Fig. 2 B is the whole front elevation of the injection hose among Fig. 1;

Fig. 3 A shows the perspective view according to another injection hose of the present invention, and its part is dissectd;

Fig. 3 B shows the perspective view according to another injection hose of the present invention, and its part is dissectd;

Fig. 4 A shows the view of an example of traditional injection hose;

Fig. 4 B shows the partial enlarged view of the traditional injection hose among Fig. 4 A;

Fig. 5 A and Fig. 5 B show the view of hose clip;

Fig. 6 is the view that the typical method that is used to produce the traditional flexible pipe that has curve shape is shown;

Fig. 7 A shows the view of another traditional injection hose;

Fig. 7 B shows the sectional view of the injection hose of Fig. 7 A.

Embodiment

In Fig. 1 and Fig. 2,reference character 10 expression is used for carrying will be from the injection hose (hereinafter abbreviating flexible pipe as) of the fuel of the injected fuel tank of going into automobile or Motor Vehicle of fuel inlet.Thisflexible pipe 10 can also be used as other flexible pipe, for example ventilation duct, exhaust tube, breathing pipe or purification pipe.Flexible pipe 10 comprises multi-layer structure, and this multi-layer structure comprises having the infiltrative resin of lowfuel blocking layer 12, be layered in theouter rubber layer 14 in these 12 outsides, resin blocking layer and be layered in theinner rubber layer 16 of interior surface layers of the qualificationflexible pipe 10 of these 12 inboards, resin blocking layer.This multi-layer structure forms the end to end that runs throughflexible pipe 10.

At this, wholeflexible pipe 10 has a curve or crooked shape.

Particularly,flexible pipe 10 has curve part 10-1,10-2 and 10-3 on the predetermined axial or lengthwise position of flexible pipe 10.And,flexible pipe 10 have straight portion that the axial opposed end byflexible pipe 10 limits or vertical tube part (flexible pipe 10 axially on the part of straight extension) 10-4 and 10-5.Flexible pipe 10 also has the straight 10-6 of portion respectively between curve part 10-1 and 10-2, have the straight 10-7 of portion between curve part 10-2 and 10-3.

The inner diameter, ID of an axial end portion offlexible pipe 10₂With external diameter OD₂Respectively than the inner diameter, ID of another axial end portion₁With external diameter OD₁Greatly.

In the present embodiment, inflexible pipe 10, each curve part 10-1,10-2 and 10-3 are progressive and increase on internal diameter and external diameter continuously along with advancing along the left direction among Fig. 2.

In this embodiment, acrylonitrile butadiene rubber (NBR) is used forinner rubber layer 16, thermoplastic fluorocarbon resin is formed or is made up of following basically by following: the copolymer of tetrafluoroethylene, hexafluoropropene and vinylidene (THV), this thermoplastic fluorocarbon resin is used to blockinglayer 12, and NBR+PVC is used forouter rubber layer 14.

At this, adhesive strength of each interlayer (one deck and adjacent layer) or bonding strength are greater than 10N/25mm, and each layer be firmly combination each other.Simultaneously, in each sample of estimating with respect to adhesive strength, on the interface of each layer, do not peel off, but mother metal is destroyed.

Inner rubber layer 16, blockinglayer 12 andouter rubber layer 14 can be made or constituted by following material and combination thereof.

Particularly, forinner rubber layer 16, for example NBR (acrylonitrile quality proportion is equal to or greater than 30%), NBR+PVC (acrylonitrile quality proportion is equal to or greater than 30%), FKM or hydrogenated acrylonitrile butadiene rubber materials such as (H-NBR) are applicable.

The wall thickness ofinner rubber layer 16 can be about 1.0 to 2.5mm.

For theblocking layer 12 as the mesosphere, for example THV, polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer (ETFE), CTFE (CTFE), ethylene-vinyl alcohol copolymer (EVOH), poly-naphthalenedicarboxylic acid fourth diester (PBN), polybutylene terephthalate (PBT) or polyphenylene sulfide materials such as (PPS) are applicable.

The wall thickness on blockinglayer 12 can be about 0.03 to 0.3mm.

THV and EVOH and PVDF are in a ratio of flexibility, are suitable for as the barrier material with flexible pipe of resin and rubber layer.Compare with EVOH with polytetrafluoroethylene (PTFE), ETFE and THV are extruded easily, are laminated on the rubber easily, and have excellent rubber adhesion.

On the other hand, it is relatively poor that PBN compares the THV flexibility with PBT.Yet the anti-fuel penetrability of PBN and PBT is superior, can be thin-walled than THV.Therefore, flexible hose also can be formed by PBN that is similar to THV and PBT.

On the other hand, forouter rubber layer 14, for example materials such as NBR+PVC, epichlorohydrin rubber (ECO), chlorosulfonated polyethylene rubber (CSM), NBR+ acrylate rubber (NBR+ACM), NBR+ ethylene propylene diene rubber (NBR+EPDM), butyl rubber (IIR), EPDM or IIR+EPDM are applicable.

The wall thickness ofouter rubber layer 14 can be about 1.0 to 3.0mm.

In the present embodiment, the rubber hardness ofouter rubber layer 14 is in equaling 75 degree or lower scope, and the rubber hardness ofinner rubber layer 16 is in equaling 70 degree or higher scope, and the rubber hardness ofinner rubber layer 16 is than high 10 degree or more of rubber hardness of outer rubber layer 14.Yet, as long as the rubber hardness ofinner rubber layer 16 is higher than the rubber hardness ofouter rubber layer 14, then the rubber hardness of the rubber hardness ofouter rubber layer 14 orinner rubber layer 16 can be made as different numerical value, and the difference between the rubber hardness of the rubber hardness ofinner rubber layer 16 andouter rubber layer 14 also can be made as different value.

According to the present invention, inflexible pipe 10,inner rubber layer 16 is made up of individual layer.Yet as shown in Figure 3A,inner rubber layer 16 can have double-layer structure, and this double-layer structure is made up of the first layer that defines innermost surface (rubber layer) 16-1 and the second layer (rubber layer) 16-2 in the outside of first layer 16-1.

In these four layers offlexible pipes 10, the adhesive strength between each layer (one deck and adjacent layer) is greater than 10N/25mm, and each layer combined closely each other.In each sample of estimating with respect to adhesive strength, on the interface of each layer, do not peel off, but mother metal is destroyed.

In these four layers offlexible pipes 10, the material that is used for each layer can be by following material be combined into.

For first layer 16-1, for example FKM, NBR (acrylonitrile quality proportion is equal to or greater than 30%), or NBR+PVC materials such as (acrylonitrile quality proportion are equal to or greater than 30%) is applicable.

The wall thickness of first layer 16-1 can be about 0.2 to 1.0mm.

On the other hand, for second layer 16-2, NBR (acrylonitrile quality proportion is equal to or greater than 30%) for example, or NBR+PVC materials such as (acrylonitrile quality proportion are equal to or greater than 30%) is applicable.

The wall thickness of second layer 16-2 can be about 1 to 2mm.

In the embodiment shown in Fig. 3 A,, can stop fuel infiltration to pass the assembly area that is connected with pipe arrangement offlexible pipe 10 effectively by using FKM as first layer 16-1.That is to say, can prevent that by intermediate barrier layers 12 inner fuel from passing wholeflexible pipe 10 to exosmosis, and stop fuel infiltration to pass the assembly area offlexible pipe 10 by having the infiltrative FKM of low fuel further.

Simultaneously, considerflexible pipe 10 is assembled to easiness on the pipe arrangement thatinner rubber layer 16 preferably has the wall thickness that is equal to or greater than 1mm in the assembly area of flexible pipe 10.Adopt the FKM of quite big thickness to form wholeinner rubber layer 16 and make involving great expense of flexible pipe 10.Yet in the embodiment shown in Fig. 3 A, second layer 16-2 can adopt for example NBR (acrylonitrile quality proportion is equal to or greater than 30%) or NBR+PVC (acrylonitrile quality proportion is equal to or greater than 30%) formation.Because NBR is cheap than FKM, so can be in the infiltrative production cost that reducesflexible pipe 10 simultaneously of the low fuel of the assembly area of keepingflexible pipe 10.

In the embodiment of Fig. 3 A, intermediate barrier layers 12 andouter rubber layer 14 can form as mentioned above.

Same in embodiment as shown in Figure 3A, the rubber hardness ofouter rubber layer 14 is equal to or less than 75 degree, and the rubber hardness ofinner rubber layer 16 is equal to or higher than 70 degree, and the rubber hardness ofinner rubber layer 16 is than high 10 degree or more of rubber hardness of outer rubber layer 14.Yet, as long as the rubber hardness ofinner rubber layer 16 is higher than the rubber hardness ofouter rubber layer 14, then the rubber hardness of the rubber hardness ofouter rubber layer 14 orinner rubber layer 16 can be made as different numerical value, and the difference between the rubber hardness of the rubber hardness ofinner rubber layer 16 andouter rubber layer 14 also can be made as different value.

Fig. 3 B shows another embodiment of theflexible pipe 10 with four-layer structure.As shown in this embodiment,flexible pipe 10 can have four-layer structure, and it comprises that (simultaneously, layer 13 andlayer 14 can be counted as outer rubber layer for intermediate rubber layer 13 betweenresin blocking layer 12 and outer rubber layer 14.In such cases, layer 13 is first layers of outer rubber layer, and is second layers of outer rubber layer as theoutermost layer 14 among Fig. 3 B).

In these four layers offlexible pipes 10, the adhesive strength between each layer (one deck and adjacent layer) is greater than 10N/25mm, and each layer be tight bond each other.In each sample of estimating with respect to adhesive strength, on the interface of each layer, do not peel off, but mother metal is destroyed.

Resin blocking layer 12 andinner rubber layer 16, andresin blocking layer 12 and intermediate rubber layer 13 respectively by sulfuration in conjunction with being bonded to each other, but also can be bonded to each other by bonding.

In these four layers offlexible pipes 10, the material that is used for each layer can be become by following combination of materials.

Forinner rubber layer 16, FKM, NBR (acrylonitrile quality proportion is equal to or greater than 30%), or the material of NBR+PVC (acrylonitrile quality proportion is equal to or greater than 30%) is applicable.

The wall thickness ofinner rubber layer 16 can be about 0.2 to 1.0mm.

For theresin blocking layer 12 as the mesosphere, for example fluororesin such as THV, PVDF or ETFE and for example polyamide resin material such as PA6, PA66, PA11 or PA12 are applicable.

The wall thickness onresin blocking layer 12 can be greatly about 0.03 to 0.3mm.

On the other hand, for intermediate rubber layer 13, for example materials such as NBR (acrylonitrile quality proportion is equal to or greater than 30%), NBR+PVC (acrylonitrile quality proportion is equal to or greater than 30%), ECO, CSM, NBR+ACM, NBR+EPDM, IIR, EPDM+IIR or EPDM are applicable.

The wall thickness of intermediate rubber layer 13 can be greatly about 0.2 to 2.0mm.

Forouter rubber layer 14, the material of NBR (acrylonitrile quality proportion is equal to or greater than 30%), NBR+PVC (acrylonitrile quality proportion is equal to or greater than 30%), ECO, CSM, NBR+ACM, NBR+EPDM, IIR, EPDM+IIR or EPDM is applicable.

The wall thickness ofouter rubber layer 14 can be greatly about 1 to 3mm.

Simultaneously, total wall thickness of theflexible pipe 10 of Fig. 3 B also promptly is fit to wall thickness and is approximately 2.5 to 6.0mm.When the wall thickness offlexible pipe 10 during less than 2.5mm, the fuel of flexible pipe 10 (gasoline) anti-permeability deficiency.When the wall thickness offlexible pipe 10 during greater than 6mm,flexible pipe 10 flexible not enough.

Same in the embodiment shown in Fig. 3 B, the rubber hardness ofouter rubber layer 14 is equal to or less than 75 degree, and the rubber hardness ofintermediate rubber layer 16 is equal to or higher than 70 degree, and the rubber hardness ofinner rubber layer 16 is than high 10 degree or more of rubber hardness of outer rubber layer 14.And the rubber hardness of intermediate rubber layer 13 can be equal to or less than 75 degree, can be than the rubber hardness of intermediate rubber layer 13 high 10 degree or more of the rubber hardness of inner rubber layer 16.Yet, as long as the rubber hardness ofinner rubber layer 16 is higher than the rubber hardness ofouter rubber layer 14 and intermediate rubber layer 13, then the rubber hardness ofouter rubber layer 14, intermediate rubber layer 13 orinner rubber layer 16 can be made as different numerical value, and the difference between the rubber hardness ofinner rubber layer 16 andouter rubber layer 14, and the difference between the rubber hardness ofinner rubber layer 16 and intermediate rubber layer 13 also can be made as different value respectively.

At this, when outer rubber layer 14 (second layer of outer rubber layer) and/or intermediate rubber layer 13 (first layer of outer rubber layer) are made by IIR or EPDM+IIR,outer rubber layer 14 and/or intermediate rubber layer 13 are provided with anti-Fuel Petroleum permeability, and because IIR and EPDM+IIR have alcohol resistance, they are also as the blocking layer.Therefore, even whenresin blocking layer 12 forms thin-walled with the flexibility that improvesflexible pipe 10 and elasticity, it is not enough that the anti-Fuel Petroleum permeability offlexible pipe 10 can not become yet.

And, even replace having the infiltrative fluororesin of good anti-Fuel Petroleum by cheap PA and when making,flexible pipe 10 still can be kept enough anti-Fuel Petroleum permeability whenresin blocking layer 12.

Then, comprise the specimen of the flexible pipe of the intermediate rubber layer of being made by IIR with respect to anti-fuel permeability evaluation, its result is presented in the table 1.

Evaluation is carried out based on following manner.Prepare 4 specimen or sample flexible pipe (A), (B), (C) and (D), each all has the internal diameter of 24.4mm, the wall thickness of 4mm, the length of 300mm.

Specimen (A) has three-decker, it comprises the outer rubber layer that resin blocking layer that inner rubber layer that NBR makes, THV815 (THV815 is the THV production code member under the trade mark Dyneon of Dyneon LLC) are made and NBR+PVC make, and specimen (B) has four-layer structure, and it comprises the outer rubber layer (second layer of outer rubber layer) that inner rubber layer that NBR makes, resin blocking layer (wall thickness 0.11mm) that THV815 makes, intermediate rubber layer (first layer of outer rubber layer) that IIR makes and NBR+PVC make.

Specimen (C) has four-layer structure, it comprises the outer rubber layer (second layer of outer rubber layer) that inner rubber layer that NBR makes, resin blocking layer (wall thickness 0.11mm) that THV815 makes, intermediate rubber layer (first layer of outer rubber layer) that IIR makes and NBR+PVC make, and specimen (D) has four-layer structure, and it comprises the outer rubber layer (second layer of outer rubber layer) that inner rubber layer that NBR makes, resin blocking layer that PA11 makes, intermediate rubber layer (first layer of outer rubber layer) that IIR makes and NBR+PVC make.

In table 1, in " sample " and " wall thickness " row, only expressed the material and the wall thickness of resin blocking layer and intermediate rubber layer (, having only resin blocking layer and outer rubber layer) respectively for specimen (A).

At specimen (A), (B), in (C) and (D) each, cooperating external diameter at each end load pressure is 25.4mm and the rounded corner metal tube (pipe arrangement) that is provided with two lug bosses (each has the maximum outside diameter of 27.4mm), and each metal tube is closed by stopper.And, test fluid flow (ethanol (E) of fuel C+10 volume %) supplies to each specimen (A) by other metal tube, (B), (C) and (D), and these other metal tubes are closed by the thread type stopper, test fluid flow is packaged in each specimen (A), (B), (C) and (D) in.Then, allow each specimen (A), (B), (C) and (D) place 3000 hours (test fluid flow of replacing in per 168 hours) down at 40 ℃.Then, according to CARB (California air resources office, California Air Resources Board) (steam detects and uses sealed case SHED, Sealed Housing for EvaporativeDetection) method is based on DBL (diurnal breathing loss, Diurnal BreathingLoss) pattern, test each specimen (A) continuous three day every day, (B), and the infiltration capacity of hydrocarbon (HC) (C) and (D).About specimen (A), (B), (C) and (D) in each is when detecting the maximum infiltration capacity of HC, with its infiltration capacity as one day HC.

Table 1

	A	B	C	D
					Sample	THV815/NBR+PVC	THV815/IIR	THV815/IIR	PA11/IIR
Wall thickness (mm)	0.11/2.16	0.11/1.9	0.08/1.9	0.20/1.9
					Infiltration capacity (mg/ flexible pipe)	4.2	2.7	4.2	3.8

As mentioned above, when combined material forms the flexible pipe of four-layer structure by selecting from the above material, the hypotonicity to conveyance fluid in the fuel transporting hose can further improve, or acid fastness gasoline performance can further improve, or heat resistance and anti-ethanol vapor oiliness are improved.

In the above-described embodiments, the present invention is applied to the flexible pipe of the diameter of an axial end portion greater than another axial end diameter.Yet the diameter that the present invention can also be applied to an axial end portion equals the flexible pipe of another axial end diameter.

According to aforesaid embodiment, when an end offlexible pipe 10 is assemblied on the pipe arrangement and this end offlexible pipe 10 when being clamped by hose clip, can be under the even and required surface pressure that makes progress in whole week of flexible pipe, the interior perimeter surface offlexible pipe 10 ends is clamped with the outer surface of pipe arrangement each other in intimate contact mutually, thereby guaranteed the sealability of expectation.

In the present embodiment, because having the soft rubber material of low rubber hardness and high deformability when being clamped by hose clip by the outer surface in the end offlexible pipe 10, outer rubber layer 14 (orouter rubber layer 14 and intermediate rubber layer 13) forms, advantageously be out of shape so this outer rubber layer 14 (orouter rubber layer 14 and intermediate rubber layer 13) can be followed the fastening action of hose clip, thereby prevent from producing distortion on the outer surface of thisouter rubber layer 14 and be delivered to the hardenedresin blocking layer 12 in the middle of being positioned onflexible pipe 10 thickness directions and pass on theinner rubber layer 16 of 12 inboards, resin blocking layer by outer rubber layer 14 (orouter rubber layer 14 and intermediate rubber layer 13).

The result, permission is radially tightened middle resin blocking layer,flexible pipe 10cross sections 12 and theinner rubber layer 16 that is positioned at these 12 inboards, resin blocking layer by the uniform fastening force that makes progress in whole week of flexible pipe of hose clip, also making the interior perimeter surface offlexible pipe 10, also is that the outer surface of interior perimeter surface and the pipe arrangement ofinner rubber layer 16 closely contacts on circumferentially along whole equably.

And, becauseinner rubber layer 16 forms by comparing the rubber material that outer rubber layer 14 (orouter rubber layer 14 and intermediate rubber layer 13) has higher rubber hardness, wheninner rubber layer 16 is tightened slightly, between the interior perimeter surface of the outer surface of pipe arrangement andinner rubber layer 16, can produce high surface pressure, thereby allowinner rubber layer 16 firmly along the whole pipe arrangement that circumferentially tightens up.

Thereby guaranteed betweenflexible pipe 10 ends and pipe arrangement, to have desired high sealing performance.

The embodiment and the comparative example of theflexible pipe 10 of the multi-layer structure shown in preparation Fig. 1 and Fig. 2.Embodiment and comparative example by changing outer rubber layer rubber hardness and the combination of the rubber hardness of inner rubber layer prepare, all each embodiment and comparative example are measured and estimated to easiness and the attributes such as hypotonicity or low fuel (gasoline) permeability that are assemblied in pipe arrangement from sealability for example, with flexible pipe.In result shown in table 2 and the table 3.

About sealability, measure and estimate each of embodiment and comparative example in the starting stage with after applying thermal force.Thermal force applies according to following program.With fuel is that fuel C+E10 is packaged in each embodiment/comparative example, and it was placed 168 hours down at 60 ℃.Therefrom withdraw from or abandon fuel then, it was placed 500 hours down at 100 ℃.

The fuel of Shi Yonging is by the isooctane of 45% weight proportion herein, and the ethanol of the toluene of 45% weight proportion and 10% weight proportion is formed.

Simultaneously, the resin blocking layer in each embodiment and the comparative example has the flexural modulus of the 500MPa that measures according to JIS K7171 in table 2 and the table 3.

Particularly, assemble the above-mentioned test of easiness and anti-fuel permeability by following realization about sealability, flexible pipe.

Sealability

Metal (SUS) stopper that the opening of each embodiment and comparative example (injection hose) is had lug boss (annular relief, the external diameter of lug boss are 27.0mm, and the external diameter of stopper is 25.4mm) clogs.Then, this injection hose fastening by worm-gear type (screw type) hose clip with the moment of torsion of 2 Newton meters (Nm) by the piston part, this injection hose was placed 1 hour under 80 ℃ atmosphere environment or the longer time, under-40 ℃ atmosphere environment, placed 1 hour or the longer time, then, with 0.1MPa/ minute supercharging rate nitrogen (gas) is filled in the injection hose, check the leakage of the nitrogen (gas) between metal closures and injection hose.Estimate sealability by this kind mode.

Flexible pipe assembling easiness

The injection hose of each embodiment and comparative example is cut into the length of 50mm.Load-measuring device (load cell) is installed in metal closures, and pipe (pipe arrangement) at room temperature is inserted in the fuel hose with a constant speed of 50mm/ minute, and the flexible pipe of estimating on pipe arrangement by the load of pipe arrangement insertion assembles easiness.

Fuel (gasoline) permeability (low fuel (gasoline) permeability)

Fuel (fuel C+E10) be packaged in each embodiment and the comparative example (injection hose), and metal (SUS) stopper that the opening of each injection hose is had a lug boss clogs (external diameter of lug boss is 27.0mm, and the external diameter of stopper is 25.4mm).Then, this injection hose is fastening with the moment of torsion of 2Nm by the worm-gear type hose clip, and this injection hose is positioned under 40 ℃ the atmosphere environment.And, measured flexible pipe weight in per 168 hours calculating reducing of its weight, replacing once encapsulates fluid (fuel, i.e. fuel C+E10) up to 2000 hours after.

Table 2

Continuous table 2

Continuous table 2

Table 3

Continuous table 3

In table 2, the injection hose (comparative example 1-3) that includes the inner rubber layer of the primary condition (rubber hardness of inner rubber layer is higher than the rubber hardness of outer rubber layer) that does not satisfy rubber hardness and outer rubber layer at least in sealability, gasoline permeability (low gasoline permeability) and flexible pipe assembling easiness go up exist not enough.Especially, about sealability and gasoline permeability, all comparative example 1-3 all do not reach desired value.

In contrast, (the preferred condition of rubber hardness: the rubber hardness of inner rubber layer is than high 10 degree or higher of the rubber hardness of outer rubber layer to satisfy the supplementary condition of rubber hardness, or the rubber hardness of inner rubber layer is equal to or higher than 70 degree than high 10 degree of rubber hardness of outer rubber layer or the rubber hardness of higher and inner rubber layer, the rubber hardness of outer rubber layer is equal to or less than 75 degree) each injection hose that comprises inner rubber layer and outer rubber layer (sample 1-3) on all properties, i.e. sealability, all performance is good on gasoline permeability (low gasoline permeability) and the flexible pipe assembling easiness.

Simultaneously, comprise that the outer rubber layer of 65 degree rubber hardnesses and 70 injection hoses (this injection hose is expressed as the comparative example (comparative example 4) based on supplementary condition) of spending the inner rubber layer of rubber hardnesses do not satisfy supplementary condition herein.Yet comparative example 4 has reached desired value in the test of sealability, but fails to reach desired value in the gasoline testing permeability.

Fail detected slight seal failure if exist in sealability test, in infiltrative test, will detect gasoline and leak gasoline.Therefore, especially when detecting slight leakage, the infiltrative mensuration of gasoline is played the effect that sealability is measured simultaneously.

The injection hose that comprises the inner rubber layer of the outer rubber layers of 65 degree rubber hardnesses and 70 degree rubber hardnesses does not satisfy the infiltrative mensuration of gasoline.This also means the sealability deficiency of this injection hose.But when the sealability that does not satisfy the injection hose that the gasoline permeability measures has met or exceeded desired value, then this flexible pipe is considered to acceptable.

This is equally applicable to comprise the injection hose (this injection hose is expressed as the comparative example (comparative example 5) based on supplementary condition) of the inner rubber layer of the outer rubber layers of 70 degree rubber hardnesses and 75 degree rubber hardnesses.

Although comparative example 4 and 5 is represented as " comparative example ", they are equally in the category of claim.

In table 3, comprise that each injection hose of inner rubber layer and outer rubber layer does not all satisfy the additional requirement of rubber hardness, they do not satisfy infiltrative mensuration of gasoline and sealability deficiency.

On the contrary, satisfy the equal function admirable of every attribute of each injection hose that comprises inner rubber layer and outer rubber layer (embodiment 4 and 5) of the additional requirement of rubber hardness.

For why his-and-hers watches 2 and the given different desired value of the gasoline permeability in the table 3 (being 10 or littler in the table 2, is 5 or littler in the table 3) the reasons are as follows.Each injection hose shown in the table 3 includes the inner rubber layer of being made by FKM and each injection hose shown in the table 2 includes the inner rubber layer of being made by NBR+PVC.Injection hose in the table 3 is high-quality, more strictly to satisfy the restriction to fuel permeability than the injection hose in the table 2.Therefore, the infiltrative desired value of the gasoline in the table 3 is set to 5 or littler.Consider cost, clearly, the injection hose shown in the table 3 is more expensive.At this, in the infiltrative mensuration to gasoline, the injection hose (comparative example 6) that does not satisfy basic demand (rubber hardness of inner rubber layer is higher than the rubber hardness of outer rubber layer) has demonstrated and has satisfied basic demand but do not satisfy injection hose (comparative example 7 and the comparative example 8 of additional requirement; Although comparative example 7 and 8 is represented as " comparative example ", they are equally in the category of claim) same result, perhaps in infiltrative mensuration to gasoline, comparative example 6 even demonstrate than comparative example 7 and comparative example 8 better results.Because all comparative example 6-8 have all demonstrated the sealability that surpasses desired value, these comparative examples 6-8 all can be considered to acceptable flexible pipe.Yet, comprising by good low gasoline permeable material, for example in the injection hose of the inner rubber layer made of FKM, this injection hose may only not demonstrate the result of improvement in the gasoline permeability is measured because the rubber hardness of its inner rubber layer is higher than the rubber hardness of outer rubber layer.That is to say, comprising by (for example having the infiltrative material of good low gasoline like that not as FKM, by NBR+PVC) in the injection hose of the inner rubber layer made, this injection hose may be higher than the rubber hardness of outer rubber layer because of the rubber hardness of its inner rubber layer, and obtains to improve effectively on low gasoline permeability.Simultaneously, in table 2 and the table 3, AN=43 and AN=37.5 represent " the fine mass content of propylene is equal to or greater than 43% " and " the fine mass content of propylene is equal to or greater than 37.5% " respectively.

Although preferred embodiment as described above, these only are some embodiments of the present invention.

For example, although injection hose in the foregoing description or fuel hose do not comprise corrugated part, as long as situation allows, the present invention can be revised as injection hose or fuel hose formed has corrugated part.Perhaps, for example, the present invention can be revised as injection hose or fuel hose formed to have two-layer or more than two-layer outer rubber layer.As mentioned above, the present invention can implement by various deformation and all not break away from category of the present invention.

Claims (4)

1. fuel hose (10) that is used for the fuel conduit of automobile, this fuel hose comprises:

Multi-layer structure, it comprises: have the infiltrative resin of low fuel blocking layer (12); Be layered in the outer rubber layer (14) on the outside, described blocking layer (12); Be layered on the inboard, described blocking layer (12) and limit the inner rubber layer (16) of the interior surface layers of described fuel hose (10), on the whole length of described fuel hose (10), form described multi-layer structure;

Wherein, the rubber hardness of described inner rubber layer (16) is higher than the rubber hardness of described outer rubber layer (14).

2. fuel hose according to claim 1 (10) is characterized in that, the rubber hardness of described inner rubber layer (16) is than high 10 degree or more of rubber hardness of described outer rubber layer (14).

3. fuel hose according to claim 2 (10) is characterized in that, the rubber hardness of described inner rubber layer (16) is 70 degree or higher, and the rubber hardness of described outer rubber layer (14) is 75 degree or lower.

4. injection hose (10) that is used for fuel is delivered to the fuel tank of automobile, this injection hose comprises:

Multi-layer structure, it comprises: have the infiltrative resin of low fuel blocking layer (12); Be layered on the inboard, described blocking layer (12) and limit the inner rubber layer (16) of the interior surface layers of described injection hose (10); With the outer rubber layer (14) that is layered on the outside, described blocking layer (12), form described multi-layer structure to another axial end from an axial end of described injection hose (10);

Wherein, the rubber hardness of described outer rubber layer (14) is 75 degree or lower, and the rubber hardness of described inner rubber layer (16) is 70 degree or higher, and the rubber hardness of described inner rubber layer (16) is than high 10 degree or more of rubber hardness of described outer rubber layer (14).

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