High pressure fuel supply pump for internal combustion engine

摘要

The invention provides a high pressure fuel supply pump having a cylinder (108) being press-fitted into a pump body (100) at a press-fitted portion (108c),a plunger (102) for engaging slidably with a sliding hole (108a) which is formed at said cylinder (108), and an end of said plunger (102) is reciprocating in a pressurizing chamber (112) formed in said pump body (100), an intake valve mechanism (105, 105a) provided at a fuel inlet (220B) of said pressurizing chamber (112), a low pressure fuel passage (110) formed at said pump body (100) for introducing fuel into said fuel inlet (220B), an exhaust valve mechanism (106, 106a) provided at a fuel outlet (106b) of said pressurizing chamber (112), a seal member (120) arranged at an outer surface of a portion of said plunger (102) which is projecting from an end side of said cylinder (108) opposite to said pressurizing chamber (112) such that a fuel chamber (107) is formed by covering said end side of said cylinder (108) opposite to said pressurizing chamber (112) with said seal member (120). According to the invention, an end portion of said sliding hole (108a) of said cylinder and a lower end of an opening portion of said pump body (100) into which said cylinder is inserted are arranged to discharge into said fuel chamber (107).