JPH1089549A - Fuel hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel hose with bellows, which is excellent in barrier property and flexibility. SOLUTION: A fuel hose is made up of a rubber-based outer hose part 1 having the first straight cylindrical parts 11, and a resin-based inner hose part 2 nearly coaxially held in the outer hose part l through a cylindrical air layer 3. The inner hose part 2 has a bellows type cylindrical part 20 and the second straight cylindrical parts 21. Further, the portion of the inner hose part 2, which shifts from the second straight cylindrical part 21 to the bellows type cylindrical part 20, has an inclined wall 2k which is inclined toward the center axis side of the inner hose part 2 so that the first trough part 20co is formed on the end side of the inner hose part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel hose with a bellows.

[0002]

2. Description of the Related Art In recent years, hoses have a high flexibility,
Further, a material having a high barrier property against gas is demanded. As a hose having such characteristics, a hose having a bellows formed of a polyamide resin type or a fluororubber type (FKM type) and having a bellows cylindrical portion provided in an axial middle region is known. However, when formed of polyamide resin,
Although barrier properties are ensured, flame resistance is not sufficient because of resin. Also, when formed of fluororubber,
Fire resistant, methanol, ethanol,
The barrier property is not sufficient for fuels such as gasoline fuel containing MTBE.

[0003] A non-bellows-shaped hose in which a polyamide resin layer having a high barrier property is integrally buried in the peripheral wall of a rubber hose is also provided.
The hose is not flexible enough because it is non-bellowed.

[0004]

SUMMARY OF THE INVENTION The present invention employs a method different from the above-described hose, and an object thereof is to provide a bellows-equipped fuel hose having excellent barrier properties and flexibility.

[0005]

According to a first aspect of the present invention, there is provided a fuel hose comprising a rubber-based outer hose having a first straight cylindrical portion provided at a shaft end, and a fuel hose substantially coaxially held in the outer hose. ,
It has a bellows tube portion provided at an intermediate position in the axial direction of the outer hose portion, and a second straight tube portion provided at a position corresponding to the first straight tube portion of the outer hose portion. An inner hose portion made of a resin that forms a cylindrical air layer, and a portion of the inner hose portion that transitions from the second straight cylinder portion to the bellows cylinder portion is a bellows cylinder. The inner hose portion has an inclined wall that is inclined so as to approach the central axis side of the inner hose portion so as to form a first valley portion on the shaft end side of the portion.

A fuel hose according to a second aspect of the present invention is a rubber-based outer hose portion having a first straight cylindrical portion provided at the shaft end, and is held substantially coaxially within the outer hose portion. It has a bellows tube portion provided at an intermediate position in the longitudinal direction and a second straight tube portion provided at a position corresponding to the first straight tube portion of the outer hose portion, and forms a tubular air layer between the outer hose portion and the second straight tube portion. The outer diameter of a virtual line that virtually connects the apexes of the respective ridges of the bellows tube portion of the inner hose portion is characterized by: It is characterized in that it is set smaller than the outer diameter of the second straight cylindrical portion of the hose portion.

A fuel hose according to a third aspect of the present invention is a rubber-based outer hose portion having a first straight cylindrical portion provided at the shaft end, and is held substantially coaxially within the outer hose portion. It has a bellows tube portion provided at an intermediate position in the longitudinal direction and a second straight tube portion provided at a position corresponding to the first straight tube portion of the outer hose portion, and forms a tubular air layer between the outer hose portion and the second straight tube portion. An inner hose portion having a base material made of a resin to be formed, and provided on the inner peripheral surface side of the second straight tube portion of the inner hose portion, a mating pipe is inserted inward and substantially the first straight tube portion and the second straight tube portion. Characterized in that the second straight cylindrical portion of the inner hose portion is in close contact with the first straight cylindrical portion of the outer hose portion at the shaft end at the shaft end. And a tightly laminated structure sandwiched in the radial direction.

According to a fourth aspect of the present invention, in the fuel hose according to the third aspect, the portion of the inner hose portion which transitions from the second straight cylindrical portion to the bellows cylindrical portion is formed by the first valley portion on the shaft end side of the bellows cylindrical portion. It has an inclined wall which is inclined so as to approach the center axis side of the inner hose portion, and the inclined wall directly faces the shaft end of the seal rubber layer.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The outer hose portion according to the present invention preferably has a first bellows tube portion, but may have a non-bellows structure in some cases. The inner hose portion according to the present invention has a bellows tube portion. The wave height and pitch of the bellows portion of each bellows cylinder can be appropriately selected.

The material of the outer hose portion can be appropriately selected, but in consideration of flame resistance, abrasion resistance, oil resistance, etc., a mixture of nitrile rubber (NBR), nitrile rubber (NBR) and vinyl chloride (PVC). , Epichlorohydrin rubber (C
O, ECO) and fluoro rubber (FKM). The material of the inner hose portion can be appropriately selected, but a polyamide resin (PA) having excellent barrier properties can be employed. In particular, 11 nylon can be adopted in consideration of flexibility.

The average thickness of the outer hose portion is set in consideration of its material.
mm, and the average thickness of the inner hose portion is set in consideration of its material. In the case of a polyamide resin, the average thickness can be, for example, about 0.2 to 2 mm. Between the bellows cylinder portion of the inner hose portion and the outer hose portion, a tubular air layer into which air having a low heat transfer coefficient is charged is formed. The average thickness of the cylindrical air layer can be appropriately selected.

In the fuel hose according to the present invention, the outer hose portion and the inner hose portion are separately formed, and the inner peripheral surface of the first straight cylindrical portion of the outer hose portion and the outer peripheral surface of the second straight cylindrical portion of the inner hose portion are formed. It can be configured by fitting or binding. In this case, an adhesive layer or a heat-sealing layer can be formed in a boundary region between the inner peripheral surface of the first straight cylindrical portion of the outer hose portion and the outer peripheral surface of the second straight cylindrical portion of the inner hose portion. In the case of a heat-sealing layer, heat-sealing is performed in a state where a heat-sealing film (for example, a polyester film) is arranged in the boundary area.

[0013] In the fuel hose of the present invention, since a cylindrical air layer is formed between the bellows tube portion of the inner hose portion and the outer hose portion, when the fuel hose according to the present invention bends and deforms.
The independent deformability of the inner hose part and the outer hose part is ensured.
Further, in the fuel hose of the present invention, since the cylindrical air layer also functions as an air heat insulating layer, heat insulation for the inner hose portion that transfers fuel is ensured.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a fuel hose according to the present invention will be described below with reference to FIG. The hose according to this example includes an outer hose portion 1 and an inner hose portion 2 arranged in a central hole 1i of the outer hose portion 1. Outer hose part 1
It is formed of a first bellows tube portion 10 located in the axial middle region and a first straight tube portion 11 provided at an end in the axial direction. The first bellows tube portion 10 has an appropriate number of peaks 10a and valleys 10c extending in a ring shape. In the first bellows tube part 10, the wave height H1 between the peak part 10a and the valley part 10c is 5-7.
mm. The pitch P1 between the adjacent peaks 10a is set to about 15 to 20 mm. First
The straight tube portion 11 has an inner diameter of about 34 mm and an outer diameter of about 44 mm.

The material of the outer hose portion 1 is made of nitrile rubber and vinyl chloride (P) in consideration of flame resistance, abrasion resistance, oil resistance and the like.
VC). Outer hose part 1
It is formed by vulcanizing at about 170 to 180 ° C. by molding using a vulcanizing mold. The inner hose portion 2 is formed by a second bellows tube portion 20 located in a central region in the axial direction, and a second straight tube portion 21 provided at an end portion in the axial direction.
The second bellows tube portion 20 faces the first bellows tube portion 10 of the outer hose portion 1 and has an appropriate number of peaks 2 extending in a ring shape.
0a and a valley 20c. In the second bellows tube portion 20, the wave height H2 between the peak portion 20a and the valley portion 20c is 3 to 5
mm. The pitch P2 between the adjacent peaks 20a is set to about 4 to 6 mm. here,
H2 is smaller than H1, and P2 is smaller than P1. In a state before the inner hose portion 2 is inserted into the outer hose portion 1, the second straight cylindrical portion 21 has an inner diameter of 32 mm,
The outer diameter is set to about 34 mm. A passage hole 2i through which gasoline fuel and the like pass is formed by the inner peripheral surface of the inner hose portion 2.

The material of the inner hose portion 2 is polyamide resin (11 nylon) in consideration of barrier properties and flexibility. The inner hose part 2 is thinner than the outer hose part 1 and is formed by blow molding. In this embodiment, the outer hose part 1 and the inner hose part 2 are separately formed, the inner hose part 2 is inserted into the outer hose part 1, and the inner peripheral surface of the first straight tube part 11 of the outer hose part 1 The second straight cylinder part 2 of the hose part 2
The first straight tube portion 11 of the outer hose portion 1 and the second straight tube portion 21 of the inner hose portion 2 are bonded and integrated by an adhesive layer 21f formed in a boundary area with the outer peripheral surface of the first hose portion 1. As a result, a cylindrical air layer 3 is formed between the second bellows cylinder 20 and the first bellows cylinder 10.

The fuel hose configured as described above is mounted on a path through which gasoline fuel or the like passes, and is used for fuel supply. When assembling the fuel hose, make sure that
The extensibility and flexibility of 0 and 20 are utilized, and the assembly error can be absorbed by the bellows tube portions 10 and 20. Vibration during use can also be absorbed by the bellows tube portions 10 and 20. As described above, in the present embodiment, the cylindrical air layer 3 is formed between the inner hose part 2 and the outer hose part 1. Therefore, when the hose bends and deforms, the first bellows tube portion 10 and the second bellows tube portion 20 can be deformed independently of each other, so that the flexibility of the fuel hose is further secured.

In this embodiment, since the inner hose portion 2 and the outer hose portion 1 constitute a double hose structure, it is advantageous for securing barrier properties. In particular, since the inner hose portion 2 is formed of a polyamide resin having excellent barrier properties, it is advantageous for preventing permeation and evaporation of gasoline fuel and the like. Further, in this embodiment, since the outer hose portion 1 made of vulcanized rubber has flame resistance, the protection of the inner hose portion 2 against the flame outside the hose is ensured.

Further, since the tubular air layer 3 formed between the inner hose section 2 and the outer hose section 1 also acts as an air heat insulating layer, heat outside the hose is hardly transmitted to the inner hose section 2. Thus, the heat insulation property of the inner hose portion 2 having the passage hole 2i for transferring the fuel and the flame resistance of the inner hose portion 2 are further ensured. Further, in this embodiment, since the wave height H2 and the pitch P2 of the second bellows cylindrical portion 20 of the inner hose portion 2 are smaller than those of the outer hose portion 1, gasoline fuel or the like passing through the passage hole 2i of the inner hose portion 2 is used. It can also contribute to reducing the passage resistance and preventing turbulence.

The second bellows tube portion 20 of the inner hose portion 2 has a bellows structure and is highly flexible. Therefore, when an external force such as vibration is applied, the first straight cylindrical portion 2 which is the shaft end of the inner hose portion 2 is formed.
The portion that transitions from the first to the second bellows cylinder portion 20 rubs against the inner wall surface of the wall of the outer hose portion 1, and when the inner hose portion 2 is considerably thin, the transition portion may be damaged in some cases. There is a risk. This is even more so in vehicles where traveling vibrations having various frequencies ranging from high frequencies to low frequencies are likely to be transmitted.

In this embodiment, as can be understood from FIG. 1, the portion of the inner hose portion 2 which transitions from the second straight tube portion 21 to the second bellows tube portion 20 is provided with the bellows tube portion 20. An inclined wall 2k that is inclined so as to approach the central axis M of the inner hose portion 2, that is, to reduce the diameter, so as to form the first valley portion 20 _C0 on the axial end side of the inner hose portion 2. Therefore, it is advantageous to suppress the above-described frictional damage of the transition portion.

In particular, in the present embodiment, the portion of the outer hose portion 1 that transitions from the first straight tube portion 11 to the first bellows tube portion 10 is provided with the first shaft end side of the first bellows tube portion 10. so as to form a crest 10 _a0, away from the central axis M of the inner hose section 2, the inclined wall 1k is formed inclined i.e. as the diameter increases. Therefore, the inclined wall 1k and the inclined wall 2k can be separated from each other in the radial direction while suppressing an increase in the diameter of the outer hose portion 1. Therefore, it is more advantageous to suppress the friction damage of the above-mentioned transition portion of the inner hose portion 2.

As can be understood from FIG. 1, the inclined wall 1k and the inclined wall 2k are at substantially the same position in the axial direction. Further, in the present embodiment, as can be understood from FIG. 1, each peak portion 20 of the second bellows cylindrical portion 20 of the inner hose portion 2 is formed.
The outer diameter Da of the imaginary line W virtually connecting the vertices of a is set smaller than the outer diameter Dc of the second straight cylindrical portion 21 of the inner hose portion 2. For this reason, while suppressing an increase in the diameter of the outer hose portion 1, each peak portion 20 a of the second bellows cylindrical portion 20 of the inner hose portion 2
Can suppress frictional damage to the inner wall surface of the wall of the outer hose portion 1, and can also secure the necessary thickness of the cylindrical air layer 3 for thermal protection of the second bellows cylindrical portion 20. It is advantageous.

(Other Example) FIGS. 2 and 3 show a main part of a second embodiment of the fuel hose according to the present invention. The second embodiment has basically the same configuration as the first embodiment, and basically has the same operation and effect. However, in this example, the inner hose part 2
On the inner surface of the second straight cylindrical portion 21, a seal rubber layer 26 having a tubular shape and elasticity is disposed. The seal rubber layer 26 is substantially parallel to the first straight cylindrical portion 11 and the second straight cylindrical portion 21 and can be formed of a rubber material having excellent fuel oil resistance, for example, a nitrile rubber (NBR) system.

In this example, as can be understood from FIG. 3, the end portion 40 of the mating pipe 4 is attached to the second straight cylindrical portion 21 of the inner hose portion 2.
Is inserted into the seal rubber layer 26 from the distal end portion 40k, and is clamped by the ring-shaped clamp member 42. 2nd straight cylinder part 21
When the mating pipe 4 is inserted into the pipe, the elasticity of the sealing rubber layer 26 ensures the insertability of the mating pipe 4 and also prevents damage to the second straight tube portion 21 of the inner hose portion 2 for transferring fuel.

Even after the mating pipe 4 is inserted, even if the inner hose section 2 made of polyamide resin is relatively hard, the elasticity of the seal rubber layer 26 allows the second straight cylindrical section 21 of the inner hose section 2 to be mated with the mating pipe. The sealing property in the boundary area with No. 4 is ensured. As described above, the sealing property of the inner hose portion 2 in the second straight tube portion 21 is ensured by the seal rubber layer 26, and in some cases, the boundary region between the inner hose portion 2 and the outer hose portion 1, the seal rubber layer 26 and the inner hose It can also be expected that the adhesive layer at the interface with the part 2 is eliminated.

In other words, as can be understood from FIGS. 2 and 3, the second straight cylindrical portion 21 of the inner hose portion 2 is provided at the shaft end.
Is tightly sandwiched between the first straight tube portion 11 of the outer hose portion 1 and the seal rubber layer 26 in the radial direction, and a tightly laminated structure is configured. Therefore, good sealing performance at the shaft end of the fuel hose is ensured. Further, also in this example, as described above, the second straight cylindrical portion 21 of the inner hose portion 2
The center axis M of the inner hose portion 2 is formed at the portion that transitions to the bellows tube portion 20 so as to form the first valley portion 20 _C0 on the shaft end side.
, That is, an inclined wall 2k that is inclined so as to reduce the diameter. As can be understood from FIGS. 2 and 3, the inclined wall 2k is formed on the shaft end 26 of the seal rubber layer 26.
Faces x directly.

Therefore, when the mating pipe 4 is inserted, the inclined wall 2k functions as a stopper for the shaft end 26x of the seal rubber layer 26. Therefore, it is advantageous for suppressing excessive press-in of the seal rubber layer 26, and is advantageous for maintaining good sealing performance by the seal rubber layer 26.

[0029]

According to the fuel hose of the present invention, since a cylindrical air layer is formed between the bellows cylinder portion of the inner hose portion and the outer hose portion, when the fuel hose is bent and deformed, The bellows tube portion of the inner hose portion and the intermediate region of the outer hose portion can be flexed and deformed independently of each other, so that the flexibility of the fuel hose is ensured. In addition, barrier properties are ensured by the inner hose portion and the outer hose portion made of resin. In particular, when the inner hose portion is formed of a polyamide resin, the barrier properties are further ensured. Therefore, it is advantageous for preventing permeation of gasoline fuel and the like.

Further, according to the fuel hose of the present invention, since the cylindrical air layer also functions as an air heat insulating layer, it is difficult for external heat to be transmitted to the inner hose portion, and the heat insulation for the inner hose portion for transferring fuel is prevented. And the flame resistance of the inner hose portion are further ensured. The above is the general effect according to the present invention,
Further, the following additional effects can be obtained.

That is, according to the fuel hose of the first aspect, a portion of the inner hose portion that transitions from the second straight cylindrical portion to the bellows cylindrical portion has the first valley portion on the shaft end side of the bellows cylindrical portion. As a result, an inclined wall that is inclined so as to approach the center axis side of the inner hose portion is formed. Therefore, it is advantageous to keep the transition portion of the inner hose portion from the second straight tube portion to the bellows tube portion as far as possible from the inner wall surface of the outer hose portion while suppressing an increase in the outer diameter of the outer hose portion. Therefore, even when the fuel hose is used in an environment where vibration acts, such as a vehicle, it is advantageous to suppress the friction damage at the transition portion.

According to the fuel hose of the second aspect,
The outer diameter of an imaginary line that virtually connects the vertices of the peaks of the bellows tube portion of the inner hose portion is set smaller than the outer diameter of the second straight tube portion of the inner hose portion. Therefore, it is advantageous to secure the required thickness of the cylindrical air layer while reducing the outer diameter of the outer hose portion. Further, since each peak of the second bellows cylinder of the inner hose part moves away from the inner wall surface of the outer hose part, it is possible to suppress friction damage to each peak of the second bellows cylinder of the inner hose part. It is advantageous.

According to the fuel hose of the third aspect, at the shaft end, the second straight cylindrical portion of the inner hose portion is connected to the first straight tube portion of the outer hose portion.
Since the close laminated structure in which the straight tube portion and the seal rubber layer are in tight contact with each other and sandwiched in the radial direction is formed, good sealing performance is secured in the second straight tube portion which is the shaft end of the inner hose portion for transferring fuel. You. Further, according to the fuel hose of the fourth aspect, the inclined wall, which is a portion of the inner hose portion that transitions from the second straight cylindrical portion to the bellows cylindrical portion, directly faces the shaft end of the seal rubber layer. Therefore, when inserting the mating pipe, the inclined wall functions as a stopper for the seal rubber layer. Therefore, excessive press-in of the seal rubber layer is regulated, which is advantageous for maintaining good sealing action by the seal rubber layer.

[Brief description of the drawings]

FIG. 1 is a sectional view of a hose according to a first embodiment.

FIG. 2 is a sectional view of a main part of a hose according to a second embodiment.

FIG. 3 is a cross-sectional view of a main part in a state where a mating pipe is inserted into a hose according to a second embodiment.

[Explanation of symbols]

In the drawing, reference numeral 1 denotes an outer hose portion, 10 denotes a first bellows tube portion, 2 denotes an inner hose portion, 20 denotes a second bellows tube portion, and 3 denotes a cylindrical air space.

Claims (4)

[Claims] An outer hose portion having a first straight cylindrical portion provided at a shaft end and having a rubber base material, an outer hose portion held substantially coaxially in the outer hose portion, and an intermediate portion of the outer hose portion in an axial direction. A bellows tube portion provided at a position and a second straight tube portion provided at a position corresponding to the first straight tube portion of the outer hose portion, and a cylindrical air layer is formed between the outer hose portion and the second straight tube portion. Characterized in that it comprises a resin-based inner hose portion, and furthermore, a portion of the inner hose portion that transitions from the second straight cylindrical portion to the bellows cylindrical portion, A fuel hose having an inclined wall that is inclined so as to approach a center axis side of the inner hose portion so as to form a first valley portion on the shaft end side of the inner hose portion. 2. An outer hose portion having a first straight cylindrical portion provided at the shaft end and having a rubber base material, a substantially coaxially held inside the outer hose portion, and an intermediate portion of the outer hose portion in an axial length direction. A bellows tube portion provided at a position and a second straight tube portion provided at a position corresponding to the first straight tube portion of the outer hose portion, and a cylindrical air layer is formed between the outer hose portion and the second straight tube portion. And an outer diameter of an imaginary line that virtually connects the apexes of the respective ridges of the bellows tube portion of the inner hose portion to the inner hose portion. A fuel hose, wherein the outer diameter of the second straight cylindrical portion of the hose portion is set smaller than the outer diameter of the hose portion. 3. An outer hose portion made of rubber and having a first straight cylindrical portion provided at a shaft end, and is held substantially coaxially in the outer hose portion, and is intermediately disposed in the axial direction of the outer hose portion. A bellows tube portion provided at a position and a second straight tube portion provided at a position corresponding to the first straight tube portion of the outer hose portion, and a cylindrical air layer is formed between the outer hose portion and the second straight tube portion. An inner hose portion having a resin base material, provided on the inner peripheral surface side of the second straight tube portion of the inner hose portion, a mating pipe is inserted inside the first hose portion and the second straight tube portion; And a substantially parallel cylindrical sealing rubber layer. Further, at a shaft end, the second straight cylindrical portion of the inner hose portion is connected to the first straight cylindrical portion of the outer hose portion and the sealing rubber layer. A fuel hose, wherein the fuel hose has a close contact laminated structure in which it is sandwiched in a radial direction in a close contact state with the fuel hose. 4. A portion of the inner hose portion which transitions from the second straight tube portion to the bellows tube portion in the inner hose portion constitutes a first valley on the shaft end side of the bellows tube portion. Fuel hose having an inclined wall inclined toward the center axis side of the inner hose portion, and the inclined wall directly faces the shaft end of the seal rubber layer.