JP2006307812A - Fuel piping - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent leakage in a connection part of a hose and a pipe. <P>SOLUTION: This fuel piping is provided with the resin hoses 10, 11 having multi-layered structures including a layer for preventing fuel transmission and with the metallic fuel pipe 9 connected with the hoses 10, 11 by the connection part 7. In the fuel piping, the fuel pipe 9 is inserted into the hoses 10, 11 in the connection part 7, and the connection part 7 is covered with a tube 18. On the hose end face 19 of the connecting part 7, transmission layers other than a layer for preventing fuel transmission are exposed. By covering the connection part 7 with the tube 18, the exposure of the transmission layers is prevented, and fuel discharge to the atmosphere can be suppressed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to liquid fuel or gaseous fuel piping.

  In recent years, due to increasing interest in environmental issues, there has been a demand for improved fuel efficiency of automobiles, and as part of this, it has been required to reduce the amount of fuel evaporation in fuel piping as much as possible. Therefore, it is conceivable to provide some non-permeable layer on the inner wall of the rubber hose having high fuel permeability. For example, Patent Document 1 discloses a hose in which an inner surface layer, a reinforcing layer, and an outer surface layer are sequentially laminated from the inside, and the inner surface layer is disposed inside the gas impermeable layer and the gas impermeable layer. A hose comprising a protective layer is described.

If the pressure difference between the inside and outside of the hose increases, the amount of fuel permeation increases, so a tank pressure control valve is provided in the fuel tank, and the tank pressure depends on the operating state of the engine, fuel temperature, and pressure inside the tank. Patent Document 2 describes an invention configured to adjust the opening of a control valve.
JP 2004-216665 A Japanese Patent Laid-Open No. 2001-165004

  According to the invention of Patent Document 1, since the gas impermeable layer is provided on the inner surface layer, the permeation of fuel from the inside of the hose to the outside of the hose is suppressed, so that the evaporation of fuel from the fuel pipe is suppressed. Can do.

  Further, according to the invention of Patent Document 2, the tank pressure control valve is opened when the operating state of the engine, the fuel temperature, or the pressure inside the tank becomes a condition for evaporating the fuel. And the permeation of fuel to the outside of the hose can be suppressed.

  However, in the invention of Patent Document 1, the protective layer that allows fuel to pass through is exposed to the outside at the hose end surface of the connecting portion with the metal pipe. Therefore, the fuel permeates to the outside through the protective layer, so that the fuel evaporates from the end surface of the hose.

  Further, the invention of Patent Document 2 has a problem that the configuration of the control device that controls the opening and closing of the tank pressure control valve is complicated.

  This invention is made in order to solve said technical subject, and it aims at suppressing the evaporation of the fuel of the hose edge part in the connection part of fuel piping.

  In order to achieve the above object, the present invention provides a fuel-impermeable resin tube at a connecting portion between a hose and a metal pipe. More specifically, the invention of claim 1 includes a resin-made fuel hose having a multilayer structure including a layer for preventing permeation of fuel, and a metal fuel pipe connected to the fuel hose by a connecting portion. In the fuel pipe in which the fuel pipe is inserted into the fuel hose in the connecting portion, the connecting portion is covered with a tube.

  The invention of claim 2 is the fuel pipe according to claim 1, wherein the entire circumference of the end of the tube on the fuel pipe side is bent inside the fuel hose.

  The invention of claim 3 is the fuel pipe according to claim 1 or 2, wherein the tube is made of resin.

  A fourth aspect of the present invention is the fuel pipe according to any one of the first to third aspects, wherein the tube has heat shrinkability.

  A fifth aspect of the present invention is the fuel pipe according to any one of the first to fourth aspects, wherein the fuel is a gas.

  According to the first aspect of the present invention, the permeation layer other than the layer that prevents the permeation of fuel is exposed at the end face of the fuel hose of the connecting portion. Then, by covering the connecting portion with the tube, the permeable layer is not exposed and the release of fuel into the atmosphere can be suppressed.

  According to the invention of claim 2, the tube covers the end face of the fuel hose of the connecting portion. Therefore, since the exposure of the end face of the fuel hose is prevented, the release of fuel into the atmosphere can be suppressed.

  Furthermore, according to the invention of claim 3, the tube is made of resin. Therefore, since the fuel impermeability can be increased, the release of fuel into the atmosphere can be suppressed.

  And according to invention of Claim 4, by applying heat at the time of tube attachment, a tube shrinks and the adhesion degree of a connection part and a tube can be improved. Therefore, the release of fuel into the atmosphere can be suppressed.

  Furthermore, according to the invention of claim 5, since the sealing degree of the connecting portion is improved by covering the tube, leakage from the connecting portion of the gaseous fuel can be suppressed, and leakage of the fuel outside the piping can be suppressed. it can.

  Next, specific examples of the present invention will be described. FIG. 3 is a diagram of a fuel supply system of an internal combustion engine to which the present invention can be applied. A fuel tank 1 is connected to a connecting portion 7 by a hose 11, and a fuel pump 2 is provided in the hose 11. The connecting portion 7 is configured to insert a rubber hose 11 into the metal pipe 9. The metal pipe 9 is provided with a fuel filter 3 and a regulator valve 4. The metal pipe 9 is connected to the entrance side of the delivery 5. The delivery 5 is provided with an injector 6 for injecting fuel into a cylinder of the internal combustion engine. The connection portion 8 on the outlet side of the delivery 5 is configured such that one end of the hose 10 is inserted into the metal pipe 9. The other end of the hose 10 is connected to the fuel tank.

  The fuel stored in the fuel tank 1 is sent to the fuel filter 3 via the hose 11 by the operation of the fuel pump 2. The fuel filtered by the fuel filter 3 is regulated by the regulator valve 4, sent to the delivery 5, injected into the cylinder from the injector 6, and combusted in the cylinder. On the other hand, the fuel not injected by the injector 6, that is, the remaining fuel is returned to the fuel tank 1 via the hose 10 connected to the outlet of the delivery 5.

  FIG. 1 is a detailed view of the connecting portions 7 and 8. The hoses 10 and 11 are multi-layer hoses made of rubber or resin, and are composed of an inner layer 12, a barrier layer 13, an intermediate layer 14, a reinforcing layer 15, and a cover layer 16 from the inside. Only the barrier layer 13 is impermeable to fuel. The outer diameter of the metal pipe 9 is configured to be equal to or slightly larger than the inner diameter of the hoses 10 and 11, and the metal pipe 9 is inserted into the hoses 10 and 11.

  The tube 18 is provided so that one end covers the outside of the cover layer 16 of the hose 10, 11 and the other end covers the outside of the fuel pipe 9, and covers the end surface 19 of the hose 10, 11. It is not exposed to the outside. In order to prevent the metal pipe 9 from falling off the hoses 10 and 11, the metal pipe 9 is clamped from the outside of the tube 18 with a clamp member 17.

  Next, the function of the tube 18 will be described. Since the fuel is volatile, a part of the fuel flowing through the hoses 10 and 11 becomes vapor and adheres to the inner layer 12. Further, the pressure inside the hoses 10 and 11 is higher than that of the hoses 10 and 11. And since the inner layer 12 permeates the fuel, the fuel reaches the hose end surface 19 through the inner layer 12 from the inside of the hoses 10 and 11, but the hose end surface 19 is covered with the tube 18 and exposed to the outside. Therefore, the release of fuel from the hose end surface 19 into the atmosphere can be suppressed.

  In addition, as shown in FIG. 2, the other end portion that covers the outside of the fuel pipe 9 may be bent inside the hoses 10 and 11. Also with this configuration, exposure of the end surfaces 19 of the hoses 10 and 11 to the outside is hindered, so that the release of fuel into the atmosphere can be suppressed.

  Furthermore, by making the tube 18 made of resin, the impermeability of the fuel can be improved and the release of the fuel into the atmosphere can be suppressed.

  In addition, the tube 18 can be heat-shrinkable. Thereby, by applying heat at the time of mounting, the degree of adhesion of the mounting can be increased, and the release of fuel into the atmosphere can be suppressed.

  Furthermore, by covering the connecting portion 7 with the tube 18, the sealing degree of the connecting portion 7 is improved, and leakage of gaseous fuel from the connecting portion 7 can be suppressed.

  In the above embodiment, the fuel pipe of the internal combustion engine has been described. However, the present invention can be applied regardless of the internal combustion engine. Further, the present invention can be applied to water and air instead of fuel. Furthermore, the fuel is not limited to liquid fuel, and the present invention can also be applied to gaseous fuel.

It is an example of the fuel piping of the internal combustion engine to which this invention is applied. This is an example in which a tube is put on the connection part. It is another example which put the tube on the connection part.

Explanation of symbols

7 ... Connection part, 9 ... Fuel pipe, 10, 11 ... Hose, 13 ... Barrier layer, 18 ... Tube, 19 ... Hose end face.

Claims (5)

A resin fuel hose having a multilayer structure including a layer for preventing permeation of fuel; and a metal fuel pipe connected to the fuel hose by a connecting portion, wherein the fuel pipe is connected to the fuel hose at the connecting portion. In the inserted fuel pipe,
A fuel pipe, characterized in that a tube is put on the connecting portion.   2. The fuel pipe according to claim 1, wherein the entire circumference of the end of the tube on the fuel pipe side is bent inside the fuel hose.   The fuel pipe according to claim 1 or 2, wherein the tube is made of resin.   The fuel pipe according to any one of claims 1 to 3, wherein the tube has heat shrinkability.   The fuel pipe according to any one of claims 1 to 4, wherein the fuel is a gas.

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