The present disclosure relates to high-pressure fuel pumps and the teaching may be applied to pumps in which a pump piston, by means of which a fuel is acted on with a high pressure, is guided in a guiding sleeve. In some embodiments, a high-pressure fuel pump may include: a housing having a housing recess; a pump piston for pressurizing a fuel; and a guiding sleeve arranged in the housing recess and guiding the pump piston. The guiding sleeve is connected to the housing recess with a materially engaging connection.

A pump body of a high-pressure pump includes a pressure chamber formed in a deep portion of a cylinder. The pump body closes the pressure chamber on a side opposite to a plunger. The plunger reciprocates within the cylinder to vary a volume of the pressure chamber. The large-diameter portion provided at an end of the plunger on a side protruding to the pressure chamber has an outside diameter larger than an inside diameter of the cylinder and smaller than an inside diameter of the pressure chamber. In this case, the large-diameter portion is engaged with a step portion between the cylinder and the pressure chamber in a state before attachment of the high-pressure pump to an internal combustion engine. Accordingly, separation of the plunger from the cylinder is avoidable.

A pump body of a high-pressure pump includes a pressure chamber formed in a deep portion of a cylinder. The pump body closes the pressure chamber on a side opposite to a plunger. The plunger reciprocates within the cylinder to vary a volume of the pressure chamber. The large-diameter portion provided at an end of the plunger on a side protruding to the pressure chamber has an outside diameter larger than an inside diameter of the cylinder and smaller than an inside diameter of the pressure chamber. In this case, the large-diameter portion is engaged with a step portion between the cylinder and the pressure chamber in a state before attachment of the high-pressure pump to an internal combustion engine. Accordingly, separation of the plunger from the cylinder is avoidable.

A fuel supply device includes: a linear actuator; a reciprocating pump having a boosting piston driven by the linear actuator and configured to reciprocate in an axial direction, the reciprocating pump being configured to suck the fuel when the boosting piston moves in a first direction and configured to boost and eject the fuel when the boosting piston moves in a second direction; and a controller configured to control driving of the linear actuator so as to adjust an amount of the fuel ejected from a boosting cylinder per reciprocating time by adjusting a ratio of a fuel ejection time and a fuel suction time of the reciprocating pump without changing the reciprocating time of the boosting piston in accordance with a load of the internal combustion engine. The adjustment adjusts a stroke length of the boosting piston and a moving speed of the boosting piston in the second direction.

A fuel supply device includes: a linear actuator; a reciprocating pump having a boosting piston driven by the linear actuator and configured to reciprocate in an axial direction, the reciprocating pump being configured to suck the fuel when the boosting piston moves in a first direction and configured to boost and eject the fuel when the boosting piston moves in a second direction; and a controller configured to control driving of the linear actuator so as to adjust an amount of the fuel ejected from a boosting cylinder per reciprocating time by adjusting a ratio of a fuel ejection time and a fuel suction time of the reciprocating pump without changing the reciprocating time of the boosting piston in accordance with a load of the internal combustion engine. The adjustment adjusts a stroke length of the boosting piston and a moving speed of the boosting piston in the second direction.

Provided is a high-pressure fuel supply pump capable of fixing a cylinder to a pump body with excellent sealability in a simple structure even at a high fuel pressure.

A high-pressure fuel supply pump including a pump body in which a pressurizing chamber is formed, and a cylinder inserted into a hole formed in the pump body and formed in a cylindrical shape, the high-pressure fuel supply pump including: a protrusion disposed at an end portion of the pump body opposite to the pressurizing chamber, formed from an outer peripheral side to an inner peripheral side with respect to an inner peripheral surface opposite to an outer peripheral surface of the cylinder, and protruding toward the cylinder, wherein the protrusion is formed so as to protrude to a side opposite to the pressurizing chamber with respect to a flat portion of the end portion of the pump body, and the protrusion is formed so as to support the cylinder from a side opposite to the pressurizing chamber.

Provided is a high-pressure fuel supply pump capable of fixing a cylinder to a pump body with excellent sealability in a simple structure even at a high fuel pressure.

A high-pressure fuel supply pump including a pump body in which a pressurizing chamber is formed, and a cylinder inserted into a hole formed in the pump body and formed in a cylindrical shape, the high-pressure fuel supply pump including: a protrusion disposed at an end portion of the pump body opposite to the pressurizing chamber, formed from an outer peripheral side to an inner peripheral side with respect to an inner peripheral surface opposite to an outer peripheral surface of the cylinder, and protruding toward the cylinder, wherein the protrusion is formed so as to protrude to a side opposite to the pressurizing chamber with respect to a flat portion of the end portion of the pump body, and the protrusion is formed so as to support the cylinder from a side opposite to the pressurizing chamber.

A pulsation damper includes an upper diaphragm, a lower diaphragm configured to form a sealed space having a predetermined pressure with the upper diaphragm, in which an inert gas is filled; and a deformation suppressing member formed of an elastic material, and comprising an inner cylindrical portion, and an extension portion extending from a center portion on an outer peripheral surface of the inner cylindrical portion such that the extension portion extends outward from a center axis of the inner cylindrical portion, wherein the deformation suppressing member is arranged inside the sealed space such that an outer periphery of the extension portion abuts against inner walls of the upper diaphragm and the lower diaphragm.

A fuel supply device includes: a linear actuator; a reciprocating pump having a boosting piston driven by the linear actuator, configured to axially reciprocate, and configured to alternately repeat suction of the fuel and ejection of the fuel more boosted than the fuel at a time of suction by reciprocation of the boosting piston; and a controller to control driving of the linear actuator. When reciprocation amplitude of the boosting piston is A (A>0) and a reciprocating cycle time is T, the controller controls the linear actuator so a maximum value of an absolute value of acceleration when the reciprocating pump sucks the fuel with an absolute value of speed of the boosting piston increasing is smaller than A.Math.(2/T).sup.2, and so a maximum value of the absolute value of the acceleration of the boosting piston when the reciprocating pump ejects the fuel is larger than A.Math.(2/T).sup.2.

A fuel supply device includes: a linear actuator; a reciprocating pump having a boosting piston driven by the linear actuator, configured to axially reciprocate, and configured to alternately repeat suction of the fuel and ejection of the fuel more boosted than the fuel at a time of suction by reciprocation of the boosting piston; and a controller to control driving of the linear actuator. When reciprocation amplitude of the boosting piston is A (A>0) and a reciprocating cycle time is T, the controller controls the linear actuator so a maximum value of an absolute value of acceleration when the reciprocating pump sucks the fuel with an absolute value of speed of the boosting piston increasing is smaller than A.Math.(2/T).sup.2, and so a maximum value of the absolute value of the acceleration of the boosting piston when the reciprocating pump ejects the fuel is larger than A.Math.(2/T).sup.2.