Fuel injection valve

Abstract

A fuel injection valve is provided with a main body and a valve member. The main body has a fuel passage and a fuel injection opening formed at the downstream-end of the fuel passage. The valve member is provided in the fuel passage. The valve member is configured to move between a first position in which the valve member closes the fuel injection opening and a second position in which the valve member opens the fuel injection opening. The fuel injection valve is further provided with a compression spring disposed in the fuel passage and a spring pin. The compression spring restrains the valve member toward the first position. The spring pin is pressedly inserted into the fuel passage for keeping the compression spring in the fuel passage. A surface of the spring pin has a resistance against sulfur.

1 . A fuel injection valve, comprising:
 a main body that comprises a fuel passage and a fuel injection opening formed at a downstream-end of the fuel passage;   a valve member that is disposed in the fuel passage, and configured to move between a first position in which the valve member closes the fuel injection opening and a second position in which the valve member opens the fuel injection opening;   a compression spring that is disposed in the fuel passage, and configured to restrain the valve member toward the first position; and   a spring pin that is tightly inserted into the fuel passage, and configured to keep the compression spring within the fuel passage, wherein a surface of the spring pin has a resistance against sulfur.   
   
   
       2 . A fuel injection valve as in  claim 1 ,
 wherein the spring pin is made of material having a resistance against sulfur.   
   
   
       3 . A fuel injection valve as in  claim 1 ,
 wherein the spring pin is made of a copper alloy having a resistance against sulfur.   
   
   
       4 . A fuel injection valve as in  claim 1 , wherein
 the spring pin is made of a copper alloy containing at least one of nickel, silicon, aluminum, and chromium, and   the at least one of nickel, silicon, aluminum, and chromium is included in the copper alloy by at least  5  percent by weight.   
   
   
       5 . A fuel injection valve as in  claim 1 ,
 wherein the spring pin is made of albata.   
   
   
       6 . A fuel injection valve as in  claim 1 ,
 wherein the surface of the spring pin is covered with material having a resistance against sulfur.   
   
   
       7 . A fuel injection valve as in  claim 6 ,
 wherein the surface of the spring pin is covered with a Ni—P alloy.   
   
   
       8 . A fuel injection valve as in  claim 1 ,
 wherein an exterior surface of the spring pin is roughened.   
   
   
       9 . A fuel injection valve as in  claim 8 , wherein the exterior surface of the spring pin is roughened by shot peening treatment.