Pump of electronic brake system

Abstract

A pump of an electronic brake system, in which an inlet valve has an improved structure so that the inlet valve is efficiently and stably opened. The inlet valve includes a valve sheet formed at the end of a piston, a switch member mounted on the valve sheet, an elastic member for applying elastic force for pushing the switch member toward the valve sheet, and a retainer for receiving the switch member and the elastic member, and a sheet contact portion of the switch member contacting the valve sheet has a planar surface. A protrusion extended toward the valve sheet is formed along the edge of the sheet contact portion so that the sheet contact portion linearly contacts the valve sheet. The switch member is made of plastic. The valve sheet having a disk shape, which the sheet contact portion contacts, is formed integrally with the piston.

1 . A pump of an electronic brake system comprising: 
 a motor installed in a bore formed in a modulate block;    a piston installed in the bore, reciprocated by the motor, and provided with a suction passage;    an outlet valve installed in the bore for forming a pressure chamber between the outlet valve and the piston;    a return spring placed in the pressure chamber for elastically supporting the piston; and    an inlet valve placed at one end of the piston and operated conversely to the operation of the outlet valve for opening and closing the suction passage, wherein:    the inlet valve includes a valve sheet formed at the end of the piston, a switch member mounted on the valve sheet, an elastic member for applying elastic force for pushing the switch member toward the valve sheet, and a retainer, receiving the switch member and the elastic member, elastically supported by the piston using the return spring; and    a sheet contact portion of the switch member contacting the valve sheet has a planar surface.    
   
   
       2 . The pump according to  claim 1 , wherein a protrusion extended toward the valve sheet is formed along the edge of the sheet contact portion so that the sheet contact portion linearly contacts the valve sheet.  
   
   
       3 . The pump according to  claim 1 , wherein an elastic member supporting portion of the switch member contacting the elastic member has a planar surface.  
   
   
       4 . The pump according to  claim 3 , wherein the elastic member supporting portion includes a protrusion inserted into the elastic member.  
   
   
       5 . The pump according to  claim 1 , wherein the switch member is made of non-metal material.  
   
   
       6 . The pump according to  claim 5 , wherein the switch member is made of plastic.  
   
   
       7 . The pump according to  claim 1 , wherein the valve sheet having a disk shape, which the sheet contact portion contacts, is formed integrally with the piston.  
   
   
       8 . The pump according to  claim 1 , wherein the elastic member is a coiled spring.