JP3733848B2 - Fuel hose connection structure and fuel hose - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel hose connection structure that is formed by fluid-tightly connecting a fuel hose and a tubular mating member such as a metal or resin pipe, and that can suppress the spread of gasoline from the connection portion to the outside, and the fuel hose connection structure. Fuel hose.
[0002]
[Prior art]
Conventionally, as this type of fuel hose, for example, as shown in JP-A-6-190974, the outer layer formed of rubber and the axial end where the mating pipe is inserted into the inner peripheral surface of the outer layer are excluded. A multi-layer hose comprising an inner layer made of resin or metal at the center has been known. That is, since the inner layer is hard, the sealing performance when overlapped with the mating pipe is not sufficient, so that both do not overlap, and the tip of the mating pipe inserted into the outer layer and the inner layer end are in contact with each other A fuel hose connection structure is provided.
[0003]
According to this connection structure, the low gasoline permeable inner layer and the subsequent mating pipe can prevent the gasoline from permeating to the outside, and the inner layer is provided at the end of the outer layer where the mating pipe is inserted. As a result, the insertion load of the mating pipe was reduced. Therefore, a predetermined low gasoline permeability can be realized by the mating pipe inserted into the inner layer position and the inner layer, and the workability of inserting the mating pipe into the fuel hose has been improved. However, in this fuel hose connection structure, since there is a slight permeation of gasoline from the contact portion between the inner layer and the mating pipe, this condition cannot be satisfied if the conditions for low gasoline permeability are further tightened. It was.
[0004]
On the other hand, as shown in, for example, Japanese Patent Application Laid-Open No. 8-294799 (see FIG. 9), the end of the fluororesin tube 2 connected to the mating pipe of the fuel hose in which the fluororesin tube 2 is covered with the protector 1 A material obtained by vulcanizing and bonding a sealant rubber 3 having a low gasoline permeability to the periphery is known. According to this fuel hose, since the low gasoline permeable seal rubber 3 is interposed between the fluororesin tube 2 and the mating pipe inserted into the tube, it is possible to reliably suppress gasoline permeation. It can meet the more stringent low gasoline permeability requirements imposed on hose connection structures.
[0005]
However, in the case of this fuel hose, even though the seal rubber 3 is interposed, since the mating pipe is inserted into the hard fluororesin tube 2, the insertion load when inserting the mating pipe is very high, There was a problem that the workability of insertion deteriorated. Further, since the seal rubber 3 is an expensive material having low gasoline permeability, the fuel hose is expensive. Furthermore, in order not to cause a gap between the fluororesin tube 2 and the seal rubber 3 when the mating pipe is inserted, it is necessary to bond the two together, which further increases the price of the fuel hose.
[0006]
[Problems to be solved by the invention]
The present invention is intended to solve the above-described problem, and satisfies the more severe conditions of low gasoline permeability and is easy to insert a mating member into the fuel hose and can be provided at low cost. And it aims at providing the fuel hose used for this.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the structural feature of the invention of claim 1 is that a tubular mating member is fluid-tightly connected in the insertion end of the fuel hose having a straight insertion end at one end in the axial direction. A fuel hose connection structure, wherein the fuel hose is coaxial with the inner peripheral surface at the inner end in the axial direction of the tubular outer layer made of an elastic body and the insertion end of the outer layer, and along the entire circumferential direction. An inner groove made of a low-gas-permeable resin material with a thin wall, which is adhesively fixed to the entire inner circumferential surface on the inner side in the axial direction including at least the groove of the outer layer, and an inner layer. An annular sealing member closely inserted into the groove, and the mating member has an annular engaging convex portion that protrudes radially outward along the entire circumference in the circumferential direction. The mating member is press-fitted into the inner peripheral surface of the insertion end of the fuel hose, and the engaging convex portion is grooved. The seal member inserted inside is pressed radially outward and engaged at the groove position, and tightened by the annular tightening member fitted at the axially outer side position with respect to the groove portion of the outer peripheral surface of the outer layer. Thus, the mating member and the fuel hose are fluid-tightly connected.
[0008]
In the invention of claim 1 configured as described above, the mating member of the mating member is in close contact with the groove provided at the axially inner end of the insertion end of the outer layer via the inner layer and the annular seal member. Therefore, it is possible to sufficiently prevent gasoline from passing therethrough. Further, in the path of press-fitting the mating member into the fuel hose, the hard inner layer is expanded only at one end of the groove and most of the outer layer is a soft outer layer, so that the insertion load can be kept low.
[0009]
Further, the structural feature of the invention of claim 2 is that, in the fuel hose connection structure according to claim 1, the outer layer and the inner layer are directed radially inward in the axial direction adjacent to the groove portion. An annular positioning convex portion protruding coaxially is provided. Thereby, it is possible to reliably prevent the seal member and the mating member from moving further inward in the axial direction from the groove portion which is the fitting end portion position.
[0010]
Further, the structural feature of the invention of claim 3 is a fuel hose having a straight insertion end at one end in the axial direction, wherein the tubular outer layer made of an elastic body and the inner end of the insertion end of the outer layer in the axial direction are provided. An annular groove formed coaxially with the inner peripheral surface at the end and along the entire circumferential direction, and a thin wall adhesively fixed to the entire inner peripheral surface on the inner side in the axial direction including at least the groove portion of the outer layer An inner layer made of a low gasoline permeable resin material, and an annular seal member that is tightly inserted in a groove covered with the inner layer, and is provided at the tip along the entire circumference and radially outward. A tubular mating member provided with a ring-shaped engaging projection protruding in the direction is press-fitted into the inner peripheral surface of the insertion end, and the sealing member mounted in the groove is pressed radially outward by the engaging projection. The ring fitted in the axially outward position with respect to the groove on the outer peripheral surface of the outer layer with the groove being engaged at the position. It is clamped by the clamping member in that the other member is connected to a fluid-tight.
[0011]
In the invention of claim 3 configured as described above, the fuel hose has a groove portion provided at the inner end in the axial direction of the insertion end portion of the outer layer and the inner layer is covered, and the annular seal member is closely inserted. Therefore, the permeation | transmission of gasoline can fully be blocked | prevented because the other party member press-fitted in the inside of the hose is fitted in the groove part by the engaging convex part. In addition, the path of the press-fitting of the mating member into the fuel hose is such that the hard inner layer is expanded only at one end of the groove and most of the outer layer is a soft outer layer, so the insertion load can be kept low.
[0012]
In the fuel hose according to claim 3, the outer layer and the inner layer are coaxially directed radially inward on the inner side in the axial direction adjacent to the groove portion. A protruding annular positioning convex portion is provided. Thus, the mating member press-fitted into the seal member and the fuel hose can be reliably prevented from moving further inward in the axial direction from the groove portion which is the fitting end portion position.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIGS. 1 and 2 are axial sectional views of a fuel hose connection structure and a fuel hose provided in a gasoline distribution path of an automobile according to the embodiment. (The lower half is omitted). The fuel hose connection structure includes a fuel hose 10 having a straight insertion end 10a at one end in the axial direction, and a metal mating pipe 21 that is a tubular mating member that is press-fitted and connected into the insertion end 10a. And an annular fastening member 25 fitted to the outer peripheral surface of the insertion end 10a.
[0014]
The fuel hose 10 includes an outer layer 11 which is a tube made of an elastic body, a groove portion 12 provided coaxially on the inner peripheral surface at an inner end in the axial direction of the insertion end portion 10 a of the outer layer 11, and an axially inner portion including the groove portion 12. An inner layer 18 made of a thin, low gasoline permeable resin material that is adhesively fixed to the entire inner peripheral surface on the side, and an annular seal member 19 tightly fitted in the groove 12 covered with the inner layer 18; It has.
[0015]
The outer layer 11 is made of any one of fluorine rubber, acrylonitrile butadiene rubber, acrylonitrile butadiene rubber / vinyl chloride, hydrogenated acrylonitrile butadiene rubber, epichlorohydrin rubber, and the like. As shown in FIG. 3, the outer layer 11 has an annular shape with a substantially square cross section that is slightly recessed radially outward along the entire circumference in the axial direction inner end of the inner peripheral surface of the insertion end portion 10a. A groove portion 12 is provided, and an annular positioning convex portion 13 that slightly protrudes coaxially in the axial direction from the inner peripheral surface along the entire radial direction is provided on the inner side in the axial direction adjacent to the groove portion 12. . In addition, about the positioning convex part 13, you may provide not only in the circumferential direction perimeter but only in a part of the circumferential direction.
[0016]
Further, on the outer peripheral surface of the outer layer 11, a portion extending slightly beyond the groove portion 12 from the inner end in the axial direction of the insertion end portion 10a to one end side in the axial direction extends along the entire circumferential direction and radially outward. The bulged annular bulging portion 14 is provided to compensate for the thin portion of the outer layer 11 due to the provision of the groove 12. Further, on the outer peripheral surface of the outer layer 11, a ring-shaped annular convex portion 15 that slightly protrudes radially outward is provided in the vicinity of one end of the insertion end portion 10 a in the axial direction. An outer peripheral portion sandwiched between the annular bulging portion 14 and the annular convex portion 15 serves as a tightening portion 16 to which a ring-shaped tightening member described later is fitted and tightened.
[0017]
On the inner peripheral surface of the outer layer 11, an inner layer 18 made of a thin, low gasoline permeable resin is bonded and fixed to the entire surface in the axial direction including the groove 12. The inner layer 18 functions as a barrier layer for gasoline-resistant permeation, and vinylidene fluoride or a fluoropolymer of vinylidene fluoride and chlorotrifluoroethylene copolymer is preferably used. The inner layer 18 is formed by forming a thin resin layer on the inner peripheral surface of the outer layer by electrostatic coating, and then subjecting the resin layer to heat treatment. When carrying out electrostatic coating, about the axial direction one end side part which does not include the groove part 12 in the insertion end part 10a of the outer layer 11, it inserts a cap from the opening side and covers this inner peripheral side in this part. Electrostatic coating is performed so that the fluororesin does not adhere.
[0018]
The sealing member 19 is a gasoline-resistant fluoro rubber, H-NBR, NBR / PVC, or NBR. The seal member 19 is made slightly larger in outer diameter than the inner diameter of the groove portion 12 including the inner layer 18. Note that the seal member 19 does not need to be bonded to the groove portion 12 and only needs to be attached.
[0019]
The insertion of the seal member 19 from the opening of the outer layer 11 into the groove portion 12 is performed using a mounting jig 30 as shown in FIG. The mounting jig 30 is provided with a pressing portion 32 slightly larger than the inner diameter of the outer layer 11 on the distal end side of the small-diameter straight rod portion 31, and further has a mounting portion 33 at the distal end of the pressing portion 32. The pressing portion 32 is formed integrally with a tapered portion 32a whose tip end side is inclined slightly outward and tapers, and an inner disc portion 32b. The mounting portion 33 has an approximately eight-shaped outer peripheral shape, and has a maximum diameter that is substantially the same as the tapered portion 32a of the pressing portion 32, and is fixed to protrude from the front surface of the tapered portion. The seal member 19 is attached to the mounting portion 33 in accordance with the 8-character shape of the mounting portion 33. The mounting jig 30 to which the seal member 19 is attached is inserted from the opening of the outer layer 11 and is press-fitted while the outer layer 11 is expanded in diameter by the pressing portion 32. When the mounting portion 33 reaches the groove portion 12, the sealing member 19 leaves the mounting portion 33 by rotating the mounting portion 33. Furthermore, the taper part 32a is pressed to the positioning convex part 13, and the seal member 19 is reliably mounted in the groove part 12. Thereby, the seal member 19 can be easily and reliably attached to the groove portion 12. However, the mounting method of the seal member 19 in the groove portion 12 is not limited to this.
[0020]
The mating pipe 21 (the mating member) is made of metal or resin, and has an annular engagement convex portion 22 that projects coaxially outward in the radial direction along the entire circumference in the circumferential direction. The outer diameter of the engaging projection 22 is slightly larger than the inner diameter of the outer layer 11. The mating pipe 21 is press-fitted into the insertion end portion 10 a of the outer layer 11, thereby being tightly inserted and fixed to the groove portion 12 provided at the inner end in the axial direction of the outer layer 11 via the inner layer 18 and the annular seal member 19. Thereafter, the ring-shaped tightening member 25 is attached to the outer peripheral surface of the tightening portion 16 of the outer layer 11 and tightened to secure a strong connection between the fuel hose 10 and the counterpart pipe 21.
[0021]
In the embodiment having the above-described configuration, the engagement convex portion 22 of the mating pipe 21 is formed in the groove portion 12 provided at the inner end in the axial direction of the insertion end portion 10a of the outer layer 11 and the inner layer 18 made of a low gasoline permeable resin material and the annular shape. Since it is tightly inserted and fixed via the seal member 19, it is possible to sufficiently prevent the gasoline from permeating and satisfy the severe low gasoline permeability condition. Further, in the press-fitting path of the mating pipe 21 to the fuel hose 10, only the one end of the groove portion 12 expands the diameter of the hard inner layer 18 and most of the soft outer layer 11, so that the insertion load can be kept low. Therefore, the workability of press-fitting the mating pipe 21 into the fuel hose 10 is improved.
[0022]
Further, on the inner side in the axial direction adjacent to the groove portion 12 of the fuel hose 10, the outer layer 11 and the inner layer 18 are provided with the annular positioning convex portion 13 that protrudes coaxially inward in the radial direction. And the movement of the counterpart member 21 further in the axial direction with respect to the groove is reliably prevented. It is possible to reliably prevent the seal member 19 and the mating member 21 from moving further inward in the axial direction from the groove 12 which is the fitting end position. As a result, the work of inserting the seal member 19 and the mating member 21 into the groove portion 12 can be performed accurately and easily.
[0023]
Next, a modification of the fuel hose connection structure according to the above embodiment will be described.
In the modification, as shown in FIGS. 6 to 8, the shape of the groove portion 42 provided in the insertion end portion 40 a of the fuel hose 40 is slightly longer in the axial direction than the groove portion 12, and The axial cross-sectional shape in which the one end side is tapered with respect to the radial direction is trapezoidal. According to the shape of the groove 42, the shape of the seal member 43 is also trapezoidal in the axial cross section. As described above, since the one end side of the groove portion 42 has a tapered shape inclined with respect to the radial direction, the inner layer 43 can be easily deformed in the diameter increasing direction, and therefore, the mounting of the seal member 43 to the groove portion 42 can be facilitated. Furthermore, the operation of inserting the mating pipe 21 is further facilitated. Moreover, since the axial length of the seal part by the groove part 42 and the seal member 43 is long, the permeation | transmission of the gasoline from a connection part with an other party pipe can be suppressed more reliably.
[0024]
The fuel hose connection structure shown in the above embodiment is an example, and can be implemented in various forms without departing from the gist of the present invention.
[0025]
【The invention's effect】
According to the first aspect of the present invention, it is possible to sufficiently prevent the gasoline from permeating at the connecting portion between the fuel hose and the counterpart member, thereby satisfying the more severe condition of low gasoline permeability. Moreover, since the insertion load of the counterpart member to the fuel hose can be kept low, the workability of insertion can be improved. Further, since the seal member fitted in the groove is a ring shape having a short axial length, it is less expensive than conventional seal rubber. Further, the positioning convex portion disposed adjacent to the inner side in the axial direction of the groove portion can surely prevent the seal member and the counterpart member from coming off from the groove portion, and can facilitate the insertion operation (the effect of the invention of claim 2). ).
[0026]
According to the third aspect of the present invention, the fuel hose can sufficiently prevent the permeation of gasoline in the connecting portion where the mating member is inserted, and can satisfy the more severe condition of low gasoline permeability. . Further, since the insertion load of the mating member can be kept low, the workability of inserting the mating member can be improved. Further, since the seal member fitted into the groove portion is a ring shape having a short axial length, it is less expensive than the conventional seal rubber. Further, the positioning convex portion arranged adjacent to the inside in the axial direction of the groove portion can surely prevent the seal member and the counterpart member from coming off from the groove portion, and can facilitate the insertion work. ).
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a fuel hose connection structure that is an embodiment of the present invention, with the lower half omitted.
FIG. 2 is a cross-sectional view in which the lower half of the fuel hose is omitted.
FIG. 3 is a partially broken sectional view showing an outer layer constituting the fuel hose.
FIG. 4 is a partially broken sectional view showing a seal rubber constituting the fuel hose.
FIG. 5 is an explanatory diagram for explaining a method of attaching a seal member to a fuel hose.
FIG. 6 is a cross-sectional view in which the lower half of a fuel hose connection structure that is a modification of the embodiment is omitted.
FIG. 7 is a cross-sectional view in which the lower half of the fuel hose is omitted.
FIG. 8 is a partially broken sectional view showing a seal rubber constituting the fuel hose.
FIG. 9 is a cross-sectional view in which the lower half of a conventional fuel hose is omitted.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Fuel hose, 10a ... Insertion end part, 11 ... Outer layer, 12 ... Groove part, 13 ... Positioning convex part, 18 ... Inner layer, 19 ... Sealing member, 21 ... Counter pipe, 22 ... Engaging convex part, 25 ... Tightening Member, 30 ... mounting jig.

Claims (4)

A fuel hose connection structure in which a tubular mating member is fluid-tightly connected to the insertion end of the fuel hose having a straight insertion end at one axial end,
The fuel hose is a tubular outer layer made of an elastic body, and an annular groove formed coaxially and along the entire circumference in the inner circumferential surface at the axially inner end of the insertion end of the outer layer. An inner layer made of a thin low-gas-permeable resin material that is adhesively fixed to the entire inner peripheral surface of the outer layer on the inner side in the axial direction including at least the groove, and the groove covered with the inner layer. An annular sealing member closely inserted,
The mating member has an annular engagement convex portion protruding at the tip along the entire circumference in the circumferential direction and radially outward;
The mating member is press-fitted into the inner peripheral surface of the insertion end portion of the fuel hose, and the engagement convex portion presses the sealing member inserted into the groove portion outward in the radial direction to In the engaged state, the mating member and the fuel hose are fluid-tightly connected by being tightened by an annular tightening member fitted at an axially outward position with respect to the groove portion of the outer peripheral surface of the outer layer. A fuel hose connection structure characterized by that. 2. The fuel hose according to claim 1, wherein an annular positioning convex portion in which the outer layer and the inner layer protrude coaxially toward a radially inner side is provided on an inner side in the axial direction adjacent to the groove portion. Connection structure. A fuel hose having a straight insertion end at one end in the axial direction, which is formed of an elastic tubular outer layer, and coaxially and circumferentially on the inner peripheral surface at the inner end in the axial direction of the insertion end of the outer layer An annular groove formed along the entire circumference, and an inner layer made of a thin low-gas-permeable resin material that is adhesively fixed to the entire inner circumferential surface on the inner side in the axial direction including at least the groove of the outer layer; An annular seal member that is closely fitted in the groove covered with the inner layer,
A tubular mating member provided with an annular engagement convex portion projecting radially outward along the entire circumference in the distal end is press-fitted into the inner peripheral surface of the insertion end portion, and the engagement convex portion An annular tightening fitted in the axially outer position of the outer peripheral surface of the outer layer with respect to the groove part in a state where the seal member mounted in the groove part is pressed radially outward and engaged at the groove part position. A fuel hose characterized by being tightened by an attaching member and fluidly connected to the mating member. 4. The fuel according to claim 3, wherein an annular positioning convex portion is provided on the inner side in the axial direction adjacent to the groove portion, the outer layer and the inner layer projecting coaxially inward in the radial direction. hose.

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