Electromagnetic fuel pump

Abstract

In a plunger type electromagnetic fuel pump, a cost reduction is achieved by reducing a number of parts in conjunction with a layout of a check valve and making a cleaning step after assembling unnecessary. In an electromagnetic fuel pump ( 1 ) which pressure-feeds a fuel from a pressurizing chamber ( 6 ) formed on the front side of a plunger ( 3 ) by controlling a current application to an electromagnetic coil ( 5 ) and repeating generation and elimination of a magnetic force so as to slidably reciprocate the plunger ( 3 ) arranged in a cylinder ( 4 ), spring retaining members ( 36 ) provided with spring guides ( 361 ) retaining proximal end sides of return springs ( 33 ) urging valve members ( 32, 32 ) of check valves ( 30, 70 ) forming the pressurizing chamber ( 6 ) integrally has fixing structures for fixing them to mounting positions, and are fixed without using the other fixing means.

1 . An electromagnetic fuel pump comprising:
 a cylinder having a discharge port provided with a check valve and an intake port on a proximal end side thereof;   a plunger slidably fitted in the cylinder, the plunger having a fuel passage formed along an axis thereof and provided with a check valve therein on a leading end side thereof;   a return spring arranged on the proximal end side between the plunger and the cylinder for urging the plunder in a leading end side direction; and   an electromagnetic coil arranged on the outside of the cylinder, a current application to the electromagnetic coil being controlled so as to repeat generation and elimination of a magnetic force to cause the plunder to slidably reciprocate for delivering a fuel under pressure;   wherein at least the check valve provided in the plunger has a spring retaining member having a spring guide retaining a discharge side of the return spring urging a valve member thereof in a valve closing direction, and a fixing structure to the discharge port of the plunger or the cylinder.   
   
   
       2 . The electromagnetic fuel pump as claimed in  claim 1 , wherein the fixing structure of the spring retaining member comprises an outer peripheral side extending from the proximal end side of the spring guide in a centrifugal direction with respect to a center axis of the fuel passage, the outer peripheral side of the spring retaining member being fitted in an inner peripheral surface of the mounted position in close contact therewith, the spring retaining member being fixed on the basis of the elastic repulsion force of the fixing structure itself. 
   
   
       3 . The electromagnetic fuel pump as claimed in  claim 1 , wherein the spring retaining member is made of a synthetic resin having an appropriate elasticity. 
   
   
       4 . The electromagnetic fuel pump as claimed in  claim 2 , wherein the spring retaining member is made of a synthetic resin having an appropriate elasticity.