Fuel supply system for internal combustion engines having fuel leakage restricting structure

Abstract

A delivery pipe of a fuel supply system for injectors mounted on a cylinder head is divided for each injector or a group of injectors. Divided pipe parts are coupled with each other through a flexible member to allow flexing of the delivery pipe. Each injector is connected with the delivery pipe through a flexible coupling member and with the cylinder head through a flexible cushioning member. Alternatively, a fuel passage is formed in the cylinder head in place of the delivery pipe to supply fuel to the injectors after heating in the cylinder head.

What is claimed is:  
     
         1 . A fuel supply system for an internal combustion engine having a plurality of cylinders, the fuel supply system comprising: 
 injectors mounted on the engine for injecting fuel into the engine; and    a delivery pipe coupled with the injectors for supplying the fuel to the injectors, the delivery pipe including a plurality of pipe parts and a flexible connecting part connecting adjacent two of the pipe parts and having a substantially same fuel passage diameter as that of the pipe parts, and the connecting part being flexible to allow flexing of the pipe parts.    
     
     
         2 . A fuel supply system of    claim 1   , wherein the injectors are mounted on a cylinder head of the engine for injecting the fuel into cylinders directly, and the flexible connecting part includes a sealing member made of a flexible material and disposed between longitudinally extending ends of the pipe parts.  
     
     
         3 . A fuel supply system for an internal combustion engine having a plurality of cylinders, the fuel supply system comprising: 
 an injector mounted on the engine for injecting fuel into each cylinder of the engine;    a delivery pipe coupled with the injector for supplying the fuel to the injector; and    a flexible connecting part fitted between the delivery pipe and the injector, the connecting part being coupled flexibly with both of the delivery pipe and the injector.    
     
     
         4 . A fuel supply system of    claim 3   , wherein the connecting part includes a cylindrical flexible coupling member fitted around an extension of the delivery pipe and the injector and a plurality of flexible sealing members, one of the sealing members being disposed between the extension of the delivery pipe and the coupling member and another of the sealing members being disposed between the injector and the coupling member.  
     
     
         5 . A fuel supply system of    claim 3   , further comprising: 
 a cushioning member made of a flexible sealing material and disposed between a cylinder head of the engine and the injector.    
     
     
         6 . A fuel supply system for an internal combustion engine having a plurality of cylinders, the fuel supply system comprising: 
 an injector mounted on the engine for injecting fuel into each cylinder of the engine;    a delivery pipe coupled with the injector for supplying the fuel to the injector; and    a cushioning member made of a flexible sealing material and disposed between the injector and a cylinder head of the engine to couple the injector with the cylinder head flexibly.    
     
     
         7 . A fuel supply system of    claim 6   , further comprising: 
 a flexible connecting part fitted between the delivery pipe and the injector, the connecting part being coupled flexibly with both of the delivery pipe and the injector.    
     
     
         8 . A fuel supply system for an internal combustion engine having a plurality of cylinders, the fuel supply system comprising: 
 an injector mounted on a cylinder head of the engine for injecting fuel into each cylinder of the engine directly; and    a fuel passage formed in the cylinder head for heating the fuel therein and supplying the heated fuel to the injector of each cylinder.    
     
     
         9 . A fuel supply system of    claim 8   , further comprising: 
 a flexible sealing member disposed between the cylinder head and the injector,    wherein the fuel passage is formed to be in direct fluid communication with the injector within the cylinder head.    
     
     
         10 . A fuel supply system of    claim 8   , further comprising: 
 a connecting pipe disposed outside of the cylinder head and connected to the injector and the fuel passage for supplying the heated fuel from the fuel passage to the injector.