Fuel hose connection structure and fuel hose

A fuel hose comprising:

• a straight insertion end portion at an axial end thereof;
• a tubular outer layer made of an elastic material, the tubular outer layer having an annular groove portion formed in an inner wall of the tubular outer layer at an axially inward end of the straight insertion end portion and an annular positioning protrusion portion on the inner wall at axially inward of and adjacent to the annular groove portion, the annular groove portion being formed coaxially with the inner wall along the entire circumference of the inner wall;
• a thin-walled inner layer made of a resin material of low gasoline permeability and fixedly bonded to a portion of the inner wall, the portion including at least the annular groove portion and extending axially inward from the annular groove portion;
• and
• a thick-walled annular seal member made of an elastic material of low gasoline permeability different from the outer layer and fitted tightly into the annular groove portion entirely lined with the thin-walled inner layer such that the thick-walled annular seal member is entirely partitioned from the tubular outer layer and positioned radially outward with respect to the annular positioning protrusion portion;
• wherein:
• the straight insertion end portion is configured to receive a tubular mating member having an annular engagement protrusion protruding radially outward at an end portion thereof along the entire circumference of the tubular mating member under pressure such that the annular engagement protrusion is engaged with the annular groove portion while the annular engagement protrusion presses radially outward on the annular seal member fitted into the annular groove portion;
• and
• the tubular outer layer is configured to be fitted with an annular clamp member at a position located axially outward with respect to the annular groove portion in such a manner as to tighten the tubular outer layer securely so as to connect the tubular mating member and the fuel hose in a fluid-tight condition.

A fuel hose connection structure comprising:

• a fuel hose having a straight insertion end portion at an axial end thereof, a tubular outer layer made of an elastic material and having an annular groove portion formed in an inner wall of the tubular outer layer at an axially inward end of the straight insertion end portion, the annular groove portion being formed coaxially with the inner wall along the entire circumference of the inner wall, an inner layer of low gasoline permeability having a thin-walled tube form and made of resin, the inner layer being inserted into and detachably disposed coaxially within the tubular outer layer, the inner layer having an axially outward end portion fitted into the annular groove portion, and a thick-walled annular seal member made of an elastic material of low gasoline permeability different from the outer layer and fitted tightly into the annular groove portion entirely lined with the axially outward end portion of the inner layer such that the thick-walled annular seal member is entirely partitioned from the tubular outer layer;
• a tubular mating member having an annular engagement protrusion formed at an end portion thereof along the entire circumference of the tubular mating member in such a manner as to protrude radially outward, the tubular mating member being inserted under pressure from the end portion into the straight insertion end portion of the fuel hose such that the annular engagement protrusion is engaged with the annular groove portion while the annular engagement protrusion presses radially outward on the annular seal member fitted into the annular groove portion;
• and
• an annular clamp member fitted onto the tubular outer layer at a position located axially outward with respect to the annular groove portion and adapted to tighten the tubular outer layer securely so as to connect the tubular mating member and the fuel hose in a fluid-tight condition.

A fuel hose comprising:

• a straight insertion end portion at one axial end thereof;
• a tubular outer layer made of an elastic material, the tubular outer layer having an annular groove portion formed in an inner wall of the tubular outer layer at an axially inward end of the straight insertion end portion and an annular positioning protrusion portion on the inner wall at axially inward of and adjacent to the annular groove portion, the annular groove portion being formed coaxially with the inner wall along the entire circumference of the inner wall;
• an inner layer of low gasoline permeability having a thin-walled tube form and made of resin, the inner layer being inserted into and detachably disposed coaxially within the tubular outer layer, the inner layer having an axially outward end portion fitted into the annular groove portion;
• and
• a thick-walled annular seal member made of an elastic material of low gasoline permeability different from the outer layer and fitted tightly into the annular groove portion entirely lined with the axially outward end portion of the inner layer such that the thick-walled annular seal member is entirely partitioned from the tubular outer layer and positioned radially outward with respect to the annular positioning protrusion portion;
• wherein:
• the straight insertion end portion is configured to receive a tubular mating member having an annular engagement protrusion protruding radially outward at an end portion thereof along the entire circumference of the tubular mating member under pressure such that the annular engagement protrusion is engaged with the annular groove portion while the annular engagement protrusion presses radially outward on the annular seal member fitted into the annular groove portion;
• and
• the tubular outer layer is configured to be fitted with an annular clamp member at a position located axially outward with respect to the annular groove portion in such a manner as to tighten the tubular outer layer securely so as to connect the tubular mating member and the fuel hose in a fluid-tight condition.