A fuel hose for a fuel pipeline in an motor vehicle has a multilayer structure including a resin barrier layer having low permeability to fuel, an outer rubber layer laminated on an outer side of the barrier layer and an inner rubber layer laminated on an inner side of the barrier layer and defining an inner surface layer of the fuel hose. The multilayer structure is formed throughout an entire length of the fuel hose. A rubber hardness of the inner rubber layer is higher than a rubber hardness of the outer rubber layer.
1. A fuel hose for a fuel pipeline in a motor vehicle, comprising:
a multilayer structure including a resin barrier layer having low permeability to fuel, an outer rubber layer laminated on an outer side of the barrier layer and an inner rubber layer laminated on an inner side of the barrier layer and defining an inner surface layer of the fuel hose, the multilayer structure being formed throughout an entire length of the fuel hose:
wherein a rubber hardness of the inner rubber layer is higher than a rubber hardness of the outer rubber layer;
wherein the fuel hose further comprises a curved portion at a certain axial position thereof, one axial end portion of the fuel hose being larger in diameter than the other axial end portion thereof; and,
wherein the curved portion is formed in a shape of continuously increasing diameter toward one end of the curved portion.
2. The fuel hose as set forth in claim 1 , wherein the rubber hardness of the inner rubber layer is higher than the rubber hardness of the outer rubber layer to 10 degrees or more.
3. The fuel hose as set forth in claim 1 , wherein the rubber hardness of the inner rubber layer is 70 degrees or higher and the rubber hardness of the outer rubber layer is 75 degrees to lower.
4. A filler hose for transporting a fuel to a fuel tank of a motor vehicle, comprising:
a multilayer structure including a resin barrier layer having low permeability to fuel, an inner rubber layer laminated on an inner side of the barrier layer and defining an inner surface layer of the filler hose, and an outer rubber layer laminated on an outer side of the barrier layer, the multilayer structure being formed from one axial end to the other axial end of the filler hose;
wherein a rubber hardness of the outer rubber layer is 75 degrees or lower, a rubber hardness of the inner rubber layer is 70 degrees or higher, and the rubber hardness of the inner rubber layer is higher than the rubber hardness of the outer rubber layer by 10 degrees or more;
wherein the filler hose further comprises a curved portion at a certain axial position thereof, one axial end portion of the filler hose being larger in diameter than the other axial end portion thereof;
wherein the curved portion is formed in a shape of continuously increasing diameter toward one end of the curved portion.
5. The fuel has as set forth in claim 1 , wherein the curved portion comprises a plurality of curved portions formed at axially spaced positions.
6. The filler hose as set forth in claim 4 , wherein the curved portion comprises a plurality of curved portions formed at axially spaced positions.