High-pressure pump

Abstract

A high-pressure pump ( 1 ) is equipped with a plunger ( 13 ) that moves in a reciprocating manner, a pressurization chamber ( 121 ) in which fuel is pressurized by the plunger ( 13 ), a fuel chamber ( 16 ) that accommodates a pulsation damper ( 50 ) and through which fuel flows, and a housing ( 11 ) that houses the fuel chamber. The fuel chamber ( 16 ) is connected to a return passage ( 310 ) through which fuel is returned from the fuel chamber ( 16 ) to a fuel tank ( 301 ) In addition, a connection passage ( 68 ) that includes a throttle ( 69 ) connects the fuel chamber ( 16 ) to the return passage ( 310 ).

1 . A high-pressure pump comprising:
 a plunger that moves in a reciprocating manner;   a pressurization chamber in which fuel is pressurized by the plunger;   a fuel chamber which accommodates a pulsation damper and through which fuel flows;   a housing in which the fuel chamber is formed;   a return passage through which fuel in the fuel chamber is returned toward a fuel tank, and which is connected to the fuel chamber; and   a connecting portion, which is provided with a throttle, and which connects the fuel chamber with the return passage.   
     
     
         2 . The high-pressure pump according to  claim 1 , wherein the fuel chamber is provided with a fuel supply port for supplying fuel to this fuel chamber, and
 the connecting portion is provided at a position on the other side of the fuel supply port across the pulsation damper.   
     
     
         3 . The high-pressure pump according to  claim 1 , wherein a guide member, which directs fuel flowing from the fuel supply port toward the connecting portion, is provided in the fuel chamber and
 the guide member is configured such that fuel introduced into the fuel chamber from the fuel supply port flows around the pulsation damper to reach the connecting portion.   
     
     
         4 . The high-pressure pump according to  claim 3 , wherein the guide member directs fuel from the fuel supply port to flow sequentially through a space below the pulsation damper; a space beside the pulsation damper, on the opposite side of the fuel supply port across the pulsation damper; and a space above the pulsation damper before reaching the connecting portion. 
     
     
         5 . The high-pressure pump according to  claim 1 , wherein the connecting portion includes an inlet-side passage and an outlet-side passage,
 the throttle is provided between the inlet-side passage and the outlet-side passage, and   the throttle is smaller in passage cross-sectional area than both a downstream end of the inlet-side passage and an upstream end of the outlet-side passage.