JP2008261379A - Filler hose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filler hose having sufficient sealability when clamped with a hose clamp without deteriorating assemblability by the excessive insertion load caused when the end of the filler hose is inserted onto a mating pipe even if hard resin barrier layers are formed in the intermediate part of the cross section of the filler hose up to the axial end thereof. <P>SOLUTION: This filler hose 10 for transporting a fuel into a fuel tank is formed by laminating the resin barrier layers 12 with low permeability to the fuel together with an inner rubber layer 16 and an outer rubber layer 14 starting at one axial end to the other axial end thereof. The end part inner peripheral surface of the hose tightened by the hose clamp is formed in an axially irregular surface 34 having annular projections projecting radially inward and grooves arranged alternately to each other. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a resin-rubber composite filler hose for transporting fuel to a fuel tank, having a resin barrier layer having low permeability to fuel in the middle of the cross section.

In the filler hose that transports fuel injected from the fuel injection port of an automobile to a fuel tank, NBR + PVC (acrylonitrile), which has been excellent in vibration absorption and assembly and relatively low in fuel (gasoline) permeability. General rubber hoses such as a blend of butadiene rubber and polyvinyl chloride) have been used.
However, in the case of such a general rubber hose, it is not possible to sufficiently meet the demand for low fuel permeability that has been increasingly demanded in recent years.

Therefore, a filler hose made of a resin-rubber composite hose in which a resin layer excellent in low permeability to fuel (permeation resistance) is used as a barrier layer and laminated as an inner layer on the inner side of the outer rubber layer has been developed and used.
However, since the resin barrier layer is a hard layer that is harder than rubber in material, when this is laminated with the outer rubber layer until it reaches the shaft end of the hose, the filler hose is inserted into the mating pipe in an extrapolated state. Sometimes, the close contact between the mating pipe and the resin barrier layer on the inner surface is poor, and the sealing performance becomes insufficient.
Also, when inserting the filler hose into the mating pipe in an extrapolated state, the resin barrier layer on the inner surface is hard and the deformation resistance is large, so a large force is required during insertion work, and the filler hose connection workability It causes a problem that gets worse.

In order to solve this problem, the following Patent Document 1 discloses a filler hose as shown in FIG.
In the figure, 200 is a resin-rubber composite filler hose, 202 is an outer rubber layer, and 204 is a resin barrier layer laminated on the inner side of the outer rubber layer 202 as an inner surface layer.
In the filler hose 200, the inner surface of the outer rubber layer 202 is exposed at the end connected to the metal mating pipe 206 without exposing the inner surface of the outer rubber layer 202, and the inner surface is in direct elastic contact with the mating pipe 206. It fits in the state.

  Further, the fuel circulating inside penetrates between the exposed inner surface of the outer rubber layer 202 and the mating pipe 206, and further permeates to the outside through the end of the outer rubber layer 202 where the resin barrier layer 204 is not formed. In this filler hose 200, an annular recess 208 is formed at the end of the resin barrier layer 204, and a ring-shaped elastic seal member 210 made of fluororubber or the like and having low fuel permeability. The mating pipe 206 is fitted into the inner surface of the elastic seal member 210 in an elastic contact state.

In general, filler hoses including those shown in FIG. 8 are fixed to the mating pipe 206 in a connected state by a hose clamp 214 having a screw-type tightening mechanism.
In FIG. 8, reference numeral 212 denotes a bulge portion (bulge portion) provided in a form that bulges radially outward in the distal end portion of the mating pipe 206, and the hose clamp 214 is a resin barrier layer 204. The end portion of the outer rubber layer 202 that is not formed is fastened in the direction of diameter reduction from the outer peripheral surface at a position on the right side of the bulging portion 212 in the drawing, and is fixed to the mating pipe 206.

FIG. 9 specifically shows the configuration of the hose clamp 214.
As shown in the figure, the hose clamp 214 includes a metal band-like tightening band 230 and a tightening mechanism 234.
The fastening band 230 is provided with slit-like thread grooves 240 at one end 230A at a constant pitch in the circumferential direction, and one end 230A provided with the thread grooves 240 is replaced with the other end 230B. The screw type tightening mechanism 234 is fixed to the other end 230B.

  The tightening mechanism 234 includes a housing 236 fixed to the end portion 230B, and a male screw 238 in which a screw shaft is rotatably accommodated. The thread of the male screw 238 is the slit-shaped screw groove. 240 is engaged.

  In the case of the hose clamp 214, when the male screw 238 is rotated, one end portion 230A moves in the circumferential direction counterclockwise in the drawing along the other end portion 230B by screw feeding, and the tightening band 230 is reduced in diameter. To do. Due to the reduced diameter of the tightening band 230, the end portion of the filler hose 200, specifically, the outer rubber layer 202 of FIG.

In the filler hose 200 shown in FIG. 8, the resin barrier layer 204 is not formed at the end of the hose, and when the filler hose 200 is inserted into the mating pipe 206 in an extrapolated state, the resistance by the resin barrier layer 204 is reduced. Since it does not work strongly, the insertion work can be performed with a small force.
Further, the resin barrier layer 204 is not formed at the end, and the inner surface of the outer rubber layer 202 having elasticity is in direct contact with the mating pipe 206. Therefore, the fitting portion between the filler hose 200 and the mating pipe 206 is The sealing property can be improved.

By the way, since it is necessary to pipe the filler hose while avoiding interference with peripheral members, the filler hose usually has a predetermined bent shape.
In the case of a general rubber hose, in order to manufacture such a bent hose, as disclosed in the following Patent Document 2, the rubber hose is extruded into a long straight tube and cut into a predetermined dimension. Thereafter, an unvulcanized (or semi-cured) straight pipe hose 216 (see FIG. 10 (II)) is inserted into a metal mandrel 218 having a predetermined bent shape, and is deformed into a bent shape. After a predetermined time of heating, the vulcanization treatment is performed, and when the vulcanization treatment is completed, the bent hose 220 is extracted from the mandrel 218 to obtain a product.

However, in the case of the filler hose 200 shown in FIG. 8, such a manufacturing method cannot be adopted. Therefore, in the case of the filler hose 200 shown in FIG. 8, the outer rubber layer 202 is first injection-molded, and thereafter A resin barrier layer 204 is formed in a shape along the inner surface of the outer rubber layer 202.
As a method for forming the resin barrier layer 204 in a shape along the inner surface of the outer rubber layer 202, an electrostatic coating technique is preferably used.

In this electrostatic coating, the spray nozzle is inserted into the filler hose, specifically, the outer rubber layer 202, and the resin powder is sprayed from the spray nozzle toward the inner surface of the outer rubber layer 202 for electrostatic coating.
In this electrostatic coating, the resin powder is negatively or positively charged (usually negatively charged), and the resin powder ejected from the ejection nozzle forms an electrostatic field on the inner surface of the outer rubber layer 202 as a counter electrode (positive electrode). It flies toward the surface and adheres to the inner surface to form a resin film.
In this electrostatic coating process, in order to form the resin barrier layer 204 with a target thickness, electrostatic coating is usually performed a plurality of times.
Specifically, after the resin powder is attached to the inner surface of the outer rubber layer 202, it is heated and melted and cooled, and then the resin powder is sprayed again by electrostatic coating to perform heat melting and cooling. Then, a resin barrier layer 204 having a desired thickness is formed.

The overall manufacturing process in this case is as follows.
That is, the outer rubber layer 202 is first obtained by injection molding and then dried, and further washing and subsequent drying are performed as pre-treatment, and then the resin powder is adhered to the inner surface by electrostatic coating, and thereafter After this is melted and cooled, the second electrostatic coating of the resin powder, heat melting, and cooling solidification are performed. This is repeated a required number of times to form a resin barrier layer 204 of a desired thickness, and then a fuel-permeable ring-shaped elastic seal member 210 is fitted from the shaft end and mounted at a predetermined position.
As described above, many steps are required to manufacture the filler hose 200 shown in FIG. 8, which inevitably increases the manufacturing cost of the filler hose 200.

Accordingly, the present inventors have devised a resin-rubber composite filler hose in which an inner rubber layer is laminated on the inner side of a resin barrier layer as an inner surface layer of a hose, and a prior patent application (for example, Japanese Patent Application No. 2006-89387). (Unpublished).
FIG. 11 shows a specific example thereof. In the filler hose 246A of this laminated structure, the resin barrier layer 244 can have a low permeability (barrier property) to the transport fluid, and the inner rubber layer 242 on the inner surface makes the resin-rubber composite filler hose 246A. When inserted into the mating pipe 206 in an extrapolated state, the inner rubber layer 242 can be elastically deformed to perform the insertion work, and the force required for insertion at that time can be reduced.
Moreover, since it can connect in the state which makes the inner rubber layer 242 elastically contact the other party pipe 206, it becomes possible to improve the adhesiveness in a connection part.

Further, in the filler hose 246A of this laminated structure, since the resin barrier layer 244 can be formed until it reaches the shaft end, an expensive ring shape for permeation resistance to the transport fluid as shown in FIG. The incorporation of the elastic seal member 210 can also be omitted.
In addition, in the filler hose 246A having this laminated structure, since the resin barrier layer 244 can be formed until reaching the shaft end, the hose can be manufactured by the same manufacturing method as shown in FIG. .
Specifically, the inner rubber layer 242, the resin barrier layer 244, and the outer rubber layer 202 are extruded and cut into a laminated state to obtain a straight pipe-shaped unvulcanized or semi-vulcanized extruded product, and this It is possible to manufacture a filler hose 246A having a bent shape by inserting and deforming a mandrel having a predetermined bent shape in an extrapolated state and completely vulcanizing the deformed state.
As a result, the filler hose 246A can be manufactured at a significantly lower cost than conventional ones.

  By the way, when inserting the end of the filler hose into the mating pipe in an extrapolated state, the inner diameter of the fitting portion of the filler hose with the mating pipe is usually smaller than the outer diameter of the mating pipe. In the inserted state, a compression allowance of about 0.5 to 2 mm is secured on one side in the radial direction in the fitting portion of the filler hose with respect to the mating pipe.

  In the case of a normal hose in which the end of the hose is composed of a rubber layer alone, when tightening by the hose clamp 214 in this state, the tightening force by the tightening band 230 is even over the entire inner peripheral surface. The inner peripheral surface of the hose end is closely adhered to the outer peripheral surface of the mating pipe 206 over the entire circumference, thereby ensuring a sufficient sealing property between the hose end and the mating pipe 206. The

  However, in the filler hose 246A having the rubber-resin-rubber laminated structure shown in FIG. 11, the intermediate hard resin barrier layer 244 is formed until it reaches the shaft end. When the end portion is inserted into the extrapolated state, the end portion thereof is tightened in the reduced diameter direction from the outer peripheral surface by the hose clamp 214 in the same manner as shown in FIG. It has been found that the transmission of the clamping force by the hose clamp 214 is hindered by the intermediate resin barrier layer 244, and there is a problem that the sealing performance required between the hose end and the mating pipe 206 cannot be sufficiently obtained.

Then, when the present inventors investigated the cause, it became clear that it was as follows.
In the hose clamp 214 of the type shown in FIG. 9, when the male screw 238 is rotated, one end portion 230A of the tightening band 230 moves in the circumferential direction by screw feed along the other end portion 230B. 230 is reduced in diameter.
The hose clamp 214 tightens the end of the hose by reducing the diameter of the tightening band 230, and seals the inner peripheral surface with the outer peripheral surface of the mating pipe 206.

  However, in the case of the resin-rubber composite filler hose 246A of FIG. 11A having a hard resin barrier layer 244 in the middle of the cross section, when the diameter of the fastening band 230 is reduced and the hose ends are tightened, 11B, the inner peripheral surface of the inner rubber layer 242 partially floats radially outward from the mating pipe 206, and the sealing performance is insufficient at the same portion. turn into.

  This is because when the diameter of the tightening band 230 is reduced and the hose end is tightened, the tightening force is sufficiently transmitted to the inner rubber layer 242 due to the blocking action of the hard resin in the middle of the cross section by the barrier layer 244. Further, at this time, due to the resistance to the deformation in the diameter reducing direction by the resin barrier layer 244, the tightening portion by the fastening band 230 at the end of the hose is not uniformly reduced in diameter over the entire circumference. In the vicinity of the end 230B on the fixed side of the band 230, a deformation is generated that tends to float radially outward from the mating pipe. As a result, the sealing performance is partially deteriorated in the vicinity of the end 230B on the fixed side. It is thought to do.

That is, due to the resistance action of deformation in the diameter-reducing direction by the hard resin barrier layer 244 laminated in the middle of the cross section, the hose end portion, more specifically, the tightening portion by the tightening band 230 tries to make a flat circular shape. It is considered that deformation and strain accumulate in the vicinity of the end 230B, and the inner peripheral surface of the hose partially lifts from the outer peripheral surface of the mating pipe, resulting in deterioration of the sealing performance.
In addition, it is conceivable that the sealing performance is improved by increasing the compression allowance when inserting the hose end into the mating pipe in an extrapolated state. In this case, the hose end is inserted into the mating pipe. The insertion load at the time becomes large, and the insertion workability, that is, the assembling property deteriorates.

JP 2002-54779 A JP-A-11-90993

  The present invention is based on the above circumstances, and even when a hard resin barrier layer is formed in the middle of the cross section until reaching the shaft end, the end of the filler hose is inserted into the mating pipe in an extrapolated state. The purpose of the present invention is to provide a filler hose that does not cause a problem that the insertion load becomes excessive and the assemblability deteriorates, and that sufficient sealing performance can be obtained by clamping with a hose clamp.

  Thus, according to the first aspect, the end is extrapolated to the rigid mating pipe, and the end is clamped to the mating pipe from the outer peripheral surface by the hose clamp and fixed to the mating pipe. In a filler hose for transporting fuel to a fuel tank of an automobile, a resin barrier layer having low permeability to fuel from one shaft end to the other shaft end, and an inner rubber layer inside the barrier layer And an outer rubber layer on the outside, and within a predetermined axial length range including a tightening portion by the hose clamp and portions adjacent to both sides in the axial direction with respect to the tightening portion. The shape of the inner peripheral surface of the end portion is an uneven surface in the axial direction alternately having annular protrusions and annular grooves along the circumferential direction protruding radially inward. Or the shape of the outer peripheral surface of the mating pipe is radially outward. Characterized in that are without the surface of the axial uneven shape having a projecting portion of the annular along the circumferential direction to leave the annular groove alternately.

Effects and effects of the invention

  As described above, the present invention is a laminate of a resin barrier layer having resistance to permeation of fuel from one shaft end to the other shaft end, and inner and outer rubber layers thereof. In the filler hose having a structure, the shape of the inner peripheral surface of the hose end is not an uneven surface in the axial direction having alternating annular protrusions and annular grooves, or the shape of the outer peripheral surface of the mating pipe. The surface is an uneven surface in the axial direction having alternating annular protrusions and annular grooves.

According to the present invention, when the hose end is inserted into the mating pipe so as to be in the extrapolated state, and the hose end is tightened from the outer peripheral surface to the mating pipe by the hose clamp, Even if the inner peripheral surface of the hose end part of the hose end part is slightly lifted radially outward from the other pipe, the annular protrusion formed on the inner peripheral surface of the hose end part (the hose end part When the shape of the inner peripheral surface is an uneven surface), it is possible to maintain the state of contact with the outer peripheral surface of the mating pipe even in the part that is slightly lifted.
Further, in the portion where the protruding portion is formed, the surface pressure is partially increased by the shape effect of the protruding portion, so that the protruding portion comes into contact with the outer peripheral surface of the mating pipe under a predetermined surface pressure, thereby improving the sealing performance. Can be secured.

  Further, in the present invention, the uneven surface is formed not only in the tightening portion by the hose clamp but also in the range of the predetermined length in the front and rear in the axial direction. Even if the peripheral surface is deformed so that it floats up from the outer peripheral surface of the mating pipe at a predetermined position in the circumferential direction, the annular projecting portion is the mating part even in the portion adjacent to the tightening portion in the axial direction. Since the surface pressure of the connecting portion between the projecting portion and the mating pipe is partially increased while being in elastic contact with the pipe, the sealing performance can be ensured also by this.

  On the other hand, the present invention does not increase the compression allowance by making the fitting surface with the mating pipe at the end of the hose as a whole small, but increases the compression allowance partially along the axial direction. By forming a plurality, the projecting portions are elastically contacted with the outer peripheral surface of the mating pipe with deformation of the annular projecting portion, so the insertion load when inserting the hose end into the mating pipe is excessive. Thus, good insertion workability, that is, assembling property can be ensured.

The above is the case of forming an uneven surface on the inner peripheral surface of the hose end, but in the present invention, an uneven surface on the outer peripheral surface of the mating pipe can be formed instead.
In this case, the same effect as described above can be obtained.

In the present invention, the inner diameter of the hose end can be set smaller than the outer diameter of the mating pipe, and the compression allowance can be set when the hose end is extrapolated to the mating pipe. This compression allowance can be within a range of 0.5 to 1.0 mm on one side in the radial direction.
In this case, the protruding portion can set the protruding height from the groove bottom of the annular groove within a range of 0.02 to 1.0 mm.
Further, the axial width of the protruding portion can be set within a range of 0.02 to 2.0.
Furthermore, such protrusions can be provided continuously in the axial direction at a pitch equal to the above width.
In the case where the uneven surface is formed on the inner peripheral surface of the hose end, the annular protrusion is radially inward of the reference inner peripheral surface of the hose adjacent to the uneven surface in the axial direction. The annular groove may have a shape that is recessed outward in the radial direction from the reference inner peripheral surface.
On the other hand, when the uneven surface is formed on the outer peripheral surface of the mating pipe, the annular protrusion protrudes radially outward from the reference outer peripheral surface of the mating pipe adjacent to the uneven surface in the axial direction. In addition, the annular groove may have a shape that is recessed radially inward from the reference outer peripheral surface.
In the case where the uneven surface is formed on the outer peripheral surface of the mating pipe, the protruding height and width of the protruding portion or the pitch in the axial direction can be set in the same manner as described above.

  The occurrence of a seal failure due to the above phenomenon is likely to occur when the hose end is tightened with a worm gear type hose clamp having a screw type tightening mechanism and a tightening band shown in FIG. Such a hose clamp is effective when applied to a filler hose clamped to a mating pipe.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
1 and 2, reference numeral 10 denotes a filler hose (hereinafter simply referred to as a hose) for transporting fuel injected from a fuel injection port of an automobile to a fuel tank, from one shaft end to the other shaft end. It has a three-layered structure of a resin barrier layer 12 having low permeability to fuel, an inner rubber layer 16 inside thereof, and an outer rubber layer 14 outside.
Here, the adhesion strength of each layer exceeds 10 N / 25 mm or more and is firmly bonded to each other by vulcanization bonding.
As shown in FIG. 2A, the hose 10 has bent portions 10-1 and 10-2 at predetermined positions in the axial direction, and has a bent shape as a whole.

In this embodiment, NBR (acrylonitrile butadiene rubber: acrylonitrile amount 37.5% or more), NBR + PVC (acrylonitrile amount 37.5% or more), FKM (fluoro rubber), H-NBR (hydrogenated NBR) are used as the inner rubber layer 14. Etc.) can be preferably used.
Moreover, the thickness can be set to about 1.0-2.5 mm.

As the barrier layer 12 of the intermediate resin, THV (a thermoplastic fluororesin comprising at least a terpolymer of vinylidene fluoride, propylene hexafluoride and tetrafluoroethylene), ETFE (a copolymer of ethylene tetrafluoroethylene). Polymer), PVDF (polyvinylidene fluoride), etc., or polyamide resins such as PA11, PA12 can be suitably used.
Moreover, the thickness can be made into the thickness of about 0.03-0.3 mm.

On the other hand, as the material of the outer rubber layer 14, NBR + PVC, ECO (epichlorohydrin-ethylene oxide copolymer rubber), CSM (chlorosulfonated polyethylene rubber), NBR + ACM (acrylic rubber), NBR + EPDM (ethylene-propylene-diene rubber), EPDM + IIR ( Butyl rubber), EPDM, and the like can be preferably used.
Moreover, the thickness can be set to about 1.0-3.0 mm.

  The hose 10 of the present embodiment is extrapolated to a metal rigid mating pipe 20 having an annular bulge portion (bulge portion) 18 bulging radially outward at the tip as shown in FIG. In the state of being inserted into the hose clamp 21, the hose clamp 21 is tightened to the mating pipe 20 from the outer peripheral surface, and is clamped (fixed or locked) in a connected state.

  Here, the hose clamp 21 is a worm gear type hose clamp similar to that shown in FIG. 9, and includes a metal belt-like tightening band 22 and a tightening mechanism 24. The tightening mechanism 24 includes a housing 26 fixed to one end of the tightening band and a male screw 28 in which a screw shaft is rotatably accommodated inside the housing 26.

  In the hose clamp 21, when the male screw 28 is rotated, the end portion on the side where the slit-shaped screw groove is formed is circumferentially rotated by screw feed by rotation of the screw shaft engaging the screw thread in the screw groove. And the tightening band 22 is reduced in diameter. As a result, the end of the hose 10 is tightened against the mating pipe 20.

Thus, in this embodiment, as shown in FIGS. 2 and 3, the shape of the inner peripheral surface of the end portion of the hose 10 is such that the tightening portion by the hose clamp 21 and both axial sides of the tightening portion are axial. An annular projecting portion 30 along the circumferential direction projecting radially inward over a range of a predetermined axial length L ₁ (here, L ₁ = 20 to 25 mm) including a portion adjacent to It is an uneven surface 34 in the axial direction having alternating grooves 32.
Note the surface 34 of the concave-convex shape (in this case _L 2 = 0 to 5 mm) from the axial end a distance _{L 2} in the hose 10 is formed as a terminating portion apart.

The protrusion part 30 is formed in the cross-sectional mountain shape here. Accordingly, the annular groove 32 has a cross-sectional valley shape corresponding to this.
Further, as shown in FIG. 3, the protruding portion 30 has a shape protruding radially inward from the reference inner peripheral surface 36 of the portion adjacent in the axial direction with respect to the concave-convex surface 34. The groove 32 has a shape recessed outward in the radial direction from the reference inner peripheral surface 36.

Here, the protrusion 30 has a width W (W = 0.02 to 2.0 mm here), and the protrusion height of the groove 32 from the groove bottom is H (here H = 0.02 to 1.0 mm). It is said that.
However, the value of W is preferably set to 1 or less in consideration of fuel permeability.
The cross-sectional shapes of the top of the protrusion 30 and the groove bottom of the groove 3248 are arc-shaped surfaces (R surfaces) each having a predetermined curvature.

The inner diameter of the reference inner peripheral surface 36 is smaller than the outer diameter of the mating pipe 20, and when the end of the hose 10 is extrapolated to the mating pipe 20, the reference inner peripheral surface 36 has a predetermined compression allowance ( ΔT) is compressed radially outward.
Here, the compression allowance (ΔT) is secured on the one side in the radial direction as in the conventional case, that is, a compression allowance of 0.5 to 1.0 mm.
In addition, the hose 10 of this embodiment can be manufactured with the same manufacturing method as shown in FIG.

At that time, in the step (IV) of FIG. 10, as shown in FIG. 4, the annular grooves 40 and the protruding portions 42 having shapes corresponding respectively to the protruding portions 30 and the grooves 32 of the hose 10 at both ends of the mandrel 38. By providing the uneven surface 44 having the above, the uneven surface 34 can be formed on the inner surface of the end portion of the hose 10.
In FIG. 4, 10A represents an unvulcanized or semi-cured straight tubular hose.

In the present embodiment as described above, when the hose end is inserted into the mating pipe 20 to be in the extrapolated state, and the hose end is tightened from the outer peripheral surface to the mating pipe 20 by the hose clamp 21, the circumferential direction Even if the inner peripheral surface of the end of the hose is partially lifted radially outward from the mating pipe 20 at a predetermined location and is deformed, the hose is deformed as shown in the partially enlarged view of FIG. The annular projecting portion 30 on the inner peripheral surface of the end portion can be kept in contact with the outer peripheral surface of the mating pipe 20 even in a part that is slightly lifted (the solid line in the figure is the shape after deformation) Is shown).
Moreover, in the part which formed the protrusion part 30, since surface pressure is partially raised by the shape effect of the protrusion part 30, this protrusion part 30 contacts the outer peripheral surface of the other pipe 20 under predetermined surface pressure. Thus, sealing performance can be ensured.

  Moreover, in this embodiment, since the uneven surface 34 is formed not only in the tightening portion by the hose clamp 21 but also in a predetermined length range in the axial direction, the hose clamp 21 tightens the hose. Even if the inner peripheral surface of the end portion is deformed so as to be lifted from the outer peripheral surface of the mating pipe 20 at a predetermined portion in the circumferential direction, even in a portion adjacent to the tightening portion in the front-rear direction in the axial direction, Since the protruding portion 30 of the protruding portion 30 is in elastic contact with the mating pipe 20 and the surface pressure of the connecting portion between the protruding portion 30 and the mating pipe 20 is partially increased, the sealing property can be ensured also by this.

  On the other hand, in this embodiment, the fitting surface with the mating pipe 20 at the end of the hose does not have a small diameter as a whole to increase the compression allowance. By forming a plurality of the protrusions 30 along the ring, the protrusions 30 are brought into elastic contact with the outer peripheral surface of the mating pipe 20 with the deformation of the annular projecting parts 30, so that the end of the hose is inserted into the mating pipe 20. The insertion load at that time is not excessive, and good insertion workability, that is, assembling property can be ensured.

  In the above embodiment, the concave and convex surface 34 is formed on the inner peripheral surface of the end portion of the hose 10, but instead of this, as shown in FIG. It is also possible to form a concavo-convex surface 50 having annular projecting portions 46 projecting outward and annular grooves 48 alternately.

Also in this case, the protrusion 46 is formed into a shape protruding radially outward from the reference outer peripheral surface 52 of the opposite pipe 20 in the axial direction with respect to the concavo-convex surface 50, and the annular groove 48 is formed. The shape is recessed from the reference outer peripheral surface 52 inward in the radial direction.
Thus, the same effect as described above can also be obtained by forming the uneven surface 50 on the outer peripheral surface of the mating pipe 20.

In the above embodiment, the hose 10 has a three-layer structure. However, as shown in FIG. 7, the hose 10 can be configured with a four-layer structure.
Of these, the example of FIG. 7A shows a first layer 16-1 having an inner rubber layer inside the resin barrier layer 12 as an inner layer and a second layer 16-2 (the second layer 16-2 is an intermediate layer). It can be regarded as a rubber layer).
Also in this example, the adhesion strength of each layer exceeds 10 N / 25 mm and is firmly adhered to each other by vulcanization adhesion. Note that the samples evaluated for peeling peeled in a state where the base material was broken instead of peeling at the interface of each layer. is doing.

In this case, as the material of the first layer 16-1, materials such as FKM, NBR (acrylonitrile amount 37.5% or more), NBR + PVC (acrylonitrile amount 37.5% or more) can be suitably used.
Moreover, the thickness can be made into the thickness to about 0.2-1.0 mm.
Further, as the second layer 16-2, materials such as NBR (acrylonitrile amount of 37.5% or more), NBR + PVC (acrylonitrile amount of 37.5% or more) can be preferably used, and the thickness is about 1 to 2 mm. Can be up to.

In the example shown in FIG. 7A, for example, by using FKM as the material of the first layer 16-1, transmission from the fastening portion when connected to the mating pipe 20 can be effectively suppressed. That is, with respect to the entire hose 10, the intermediate barrier layer 12 can suppress the permeation of the internal fuel to the outside, and further, the permeation at the fastening portion can be suppressed by the low permeability FKM.
In addition, it is preferable that the inner rubber layer 16 has a thickness of 1 mm or more in terms of the insertion property with the mating pipe 20 in the fastening portion. However, if the entire inner rubber layer 16 is made thick by FKM, the hose 10 becomes expensive. turn into. However, in the example of FIG. 7A, the second layer 16-2 can be composed of NBR (acrylonitrile content 30% by mass or more) or NBR + PVC (acrylonitrile content 30% by mass or more) cheaper than FKM. The hose 10 can be made inexpensive while suppressing fuel permeation at the fastening portion.
The intermediate barrier layer 12 and the outer rubber layer 14 are the same as described above.

Also in this example, by leaving without the surface 34 of the concave-convex shape over the inner circumferential surface of the end portion of the hose 10 to the range of the axial length L _1, it is possible to achieve the same effect as described above.

FIG. 7B shows another example of the hose 10 having a four-layer laminated structure. As shown in this example, the outer rubber layer 14 is made up of the first layer 14-1 and the second layer 14- as the outer layer. 2 (the first layer 14-1 can also be regarded as an intermediate rubber layer).
Also in the hose 10 having a four-layer structure, the adhesion strength of each layer exceeds 10 N / 25 mm or more, and the layers are firmly bonded to each other. Note that the peel-evaluated sample peels in a state where the base material is broken, not peeled at the interface of each layer.
Here, the adhesion between the resin barrier layer 12 and the inner rubber layer 16 and the first layer 14-1 of the outer rubber layer 14 is vulcanization adhesion, but adhesion using an adhesive is also possible.
In this case, the material of each layer can be combined as follows.
That is, as the material of the inner rubber layer 16, FKM, NBR (acrylonitrile amount 30% by mass or more) or NBR + PVC (acrylonitrile amount 30% by mass or more) can be suitably used.
The wall thickness can be about 0.2 to 1 mm.
As the material of the intermediate resin barrier layer 12, fluorine resins such as THV, PVDF, and ETFE, and polyamide resins such as PA6, PA66, PA11, and PA12 can be preferably used.
Its thickness can be about 0.03 to 0.3 mm.
On the other hand, as the material of the first layer 14-1 in the outer rubber layer 14, NBR (acrylonitrile amount 30% by mass or more), NBR + PVC (acrylonitrile amount 30% by mass or more), ECO, CSM, NBR + ACM, NBR + EPDM, IIR (butyl rubber), EPDM + IIR EPDM can be preferably used.
The wall thickness can be about 0.2-2 mm.
As the material of the second layer 14-2, NBR (acrylonitrile content 30% by mass or more), NBR + PVC (acrylonitrile content 30% by mass or more), ECO, CSM, NBR + ACM, NBR + EPDM, IIR, EPDM + IIR, EPDM are preferably used. it can.
Its thickness can be about 1 to 3 mm.
In addition, the total thickness, that is, the thickness of the hose 10 in FIG. If the thickness of the hose 10 is less than 2.5 mm, fuel resistance (gasoline) permeability becomes insufficient, and if the thickness of the hose 10 exceeds 6 mm, flexibility is insufficient.

In the example of FIG. 7 (B), the by leaving without the uneven surface 34 of the over the inner peripheral surface of the end portion of the hose 10 to a range of predetermined axial length L _1, the same effect Can be played.

Here, when IIR or EPDM + IIR is used for the second layer 14-2 or the first layer 14-1 of the outer rubber layer 14, since the IIR and EPDM + IIR have alcohol resistance, the second layer 14-2, The first layer 14-1 has gasoline fuel permeation resistance and functions as a barrier layer. Therefore, even if the resin barrier layer 12 is formed thin and the flexibility or flexibility of the hose 10 is increased, the gasoline fuel permeation resistance of the hose 10 will not be insufficient.
Further, even if an inexpensive polyamide resin is used for the resin barrier layer 12 instead of a fluorine resin excellent in gasoline permeability resistance, the gasoline fuel permeability resistance of the hose 10 can be prevented from becoming insufficient.

Next, the hose 10 using IIR for the first layer 14-1 was evaluated with respect to gasoline fuel resistance. The evaluation results are shown in Table 1.
Evaluation was performed as follows. First, four types of hose samples or test pieces (A), (B), (C), and (D) having an inner diameter of 24.4 mm, a thickness of 4 mm, and a length of 300 mm were prepared.
The hose sample (A) has a three-layer structure of an NBR inner rubber layer 16, a THV815 (Dyneon ™ product number THV815 (THV) manufactured by Dyneon) resin barrier layer, and an NBR + PVC outer rubber layer 14. The hose sample (B) includes an NBR inner rubber layer 16, a THV815 resin barrier layer 12 (thickness 0.11 mm), an IIR outer rubber layer 14 first layer 14-1, and an NBR + PVC outer rubber layer. It is a four-layer structure of 14 second layers 14-2.
The hose sample (C) includes an NBR inner rubber layer 16, a THV815 resin barrier layer 12 (thickness 0.08 mm), an IIR first layer 14-1, and an NBR + PVC outer rubber layer 14 second layer 14-. The four-layer structure of the hose (D) is composed of the NBR inner rubber layer 16, the PA11 resin barrier layer 12, the IIR first layer 14-1, and the NBR + PVC second layer 14-2. Layer structure.
However, in each column of the test piece and thickness in Table 1, only the material and thickness of the resin barrier layer 12 and the first layer 14-1 (the resin barrier layer 12 and the outer rubber layer 14 in the hose sample (A)) are provided. Are shown respectively.
On both ends of each hose sample (A), (B), (C), (D), R-treated outer diameter 25.4 mm (maximum outer diameter 27.4 mm bulge processing part is formed in two places ) Metal pipes (mating pipes). And about each hose sample (A), (B), (C), (D), a sealing plug is attached to one metal pipe, and from the other metal pipe, the hose samples (A), (B) , (C), (D) after supplying the test solution (Fuel C + ethanol 10% by volume), the other metal pipe is fitted with a screw-type airtight stopper, and the test solution is supplied to each hose sample (A), (B ), (C), (D), and each hose sample (A), (B), (C), (D) was kept at 40 ° C. for 3000 hours (however, the test solution was 168 hours) Exchange later). Then, the amount of HC (hydrocarbon) permeation was measured for 3 days using the SHED method CARB-DBL pattern, and for each hose sample (A), (B), (C), (D), the amount of HC permeation was The permeated amount of HC per day that was the maximum was determined and used as the permeated amount.

The hose 10 having a three-layer structure shown in FIGS. 1 and 2 is configured such that the rubber hardness of the inner rubber layer 14 is 65 degrees, the rubber hardness of the outer rubber layer is 75 degrees, and the uneven surface 34 of FIG. As shown in Table 1, the width W and height H of the projecting portion 30 are changed in various ways, and the sealability is evaluated by gasoline permeability, and the insertion property when the mating pipe is inserted is determined by the mating pipe. Evaluation was made based on the insertion load at the time of insertion.
Here, the rubber hardness means the hardness according to spring type hardness (type A) defined in JIS K 6253.
The resin barrier layer 12 has a flexural modulus defined by JIS K 7171 of 500 MPa.
The results are also shown in Table 2.
The gasoline permeability and insertability shown in Table 1 were evaluated as follows.

<Gasoline permeability>
Fill the hose with fuel, close it with a SUS metal plug with a bulge (bulge diameter 27.0 mm, outer diameter 25.4 mm), and tighten it with a torque of 2 N · m with a worm gear type hose clamp shown in FIG. The fuel was drawn out and left for 3000 hours (however, the fuel is changed every 168H). Then, an HC emission test was performed using a CARB-DBL pattern in which 18.3 to 40 to 18.3 ° C. was cycled at 24H for evaluation of gasoline permeability.
The fuel used was a fuel in which isooctane: toluene: ethanol was mixed at a mixing ratio of 45 wt%: 45 wt%: 10 wt%.
The length of the filler hose was 300 mm, and the pipe insertion length was 35 mm.
<Insertability>
Cut the hose to a length of 50 mm, and attach a load measuring machine (load cell) to a SUS metal plug with a bulge (bulge diameter 27.0 mm, outer diameter 25.4 mm). The other pipe was inserted into the hose.

As can be seen from the results in Table 2, both the gasoline permeability and the insertability are insufficient when the hose end inner peripheral surface is not provided with an uneven surface. Even in the case of providing an uneven surface, if H is larger than 1 which is a desirable value or width W is larger than 2 which is a desirable value, either insertion property or gasoline permeability property. Does not meet the target value.
On the other hand, when both W and H are desirable values of 2 or less and 1 or less, both gasoline permeability and insertability are good. In particular, when the ratio of W to H is 1: 1, the balance between gasoline permeability and insertability is good.

  Although the embodiment of the present invention has been described in detail above, this is merely an example, and the present invention can be configured in various forms without departing from the spirit of the present invention.

It is a perspective view which notches and shows a part of filler hose of one Embodiment of this invention. It is the whole filler hose and principal part sectional drawing of the embodiment. It is a principal part expanded sectional view of the embodiment. It is a figure of the mandrel used for the hose manufacture of the embodiment. It is operation | movement explanatory drawing of the hose of the embodiment. It is a figure of other embodiment of this invention. It is a figure of other embodiment of this invention. It is a figure which shows an example of the conventional filler hose. It is the figure which showed the hose clamp. It is a figure which shows the general manufacturing method of the conventional bend-shaped hose. It is the figure which showed the filler hose which concerns on the prior application of this application as a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Filler hose 12 Barrier layer 14 Outer rubber layer 16 Inner rubber layer 20 Mating pipe 21 Hose clamp 30, 46 Protruding part 32, 48 Groove 34, 50 Uneven surface 36 Reference inner peripheral surface 52 Reference outer peripheral surface

Claims (1)

Filler for transporting fuel to the fuel tank of an automobile, where the end is extrapolated to a rigid mating pipe and the end is clamped to the mating pipe from the outer peripheral surface by a hose clamp and fixed to the mating pipe. In the hose, a laminated structure of a resin barrier layer having low permeability to fuel from one shaft end to the other shaft end, an inner rubber layer inside the barrier layer, and an outer outer rubber layer And the shape of the inner peripheral surface of the end portion over a range of a predetermined length in the axial direction including a tightening portion by the hose clamp and portions adjacent to the tightening portion on both sides in the axial direction. Is an irregular surface in the axial direction alternately having annular protrusions and annular grooves along the circumferential direction protruding radially inward, or the shape of the outer peripheral surface of the mating pipe is , Annular along the circumferential direction protruding radially outward Filler hose, characterized in that are without the surface of the axial uneven shape having a protrusion and an annular groove alternately.

Images