Disclosed is a method for managing a piston pump using a computer of a vehicle, the pump including a guide, a piston slidably mounted in the guide, and a solenoid, suitable for moving the piston, the method including, as long as the fuel pressure in the compression chamber of the pump is below a predetermined pressure threshold, a step of the computer controlling the solenoid in order to move the piston to its high position, and a step of the computer detecting that the predetermined pressure threshold has been exceeded when the current value, measured after a predetermined period, is greater than or equal to a predetermined reference value so that the computer ceases to control the solenoid.

A pump includes a reservoir configured to receive a fluid pressurized by a boost pump. The pump also includes at least one pumping mechanism configured to receive a first flow of fluid from the reservoir and direct the first flow of fluid into a discharge passage of the pump without pumping the first flow of fluid when priming the pump. The at least one pumping mechanism is disposed in the reservoir such that the fluid in the reservoir surrounds at least a portion of the at least one pumping mechanism. The discharge passage is configured to output the first flow of fluid from the pump. The pump further includes a bypass passage configured to communicate a second flow of fluid from the reservoir to the storage tank.

A pump unit for supplying fuel, preferably diesel oil, to an internal combustion engine has at least two cylinders (10), which are formed in at least one head (9), are slidingly engaged by respective pistons (13), and communicate hydraulically with respective fuel inlets (11) in the cylinders (10) via respective interposed intake valves (15) provided with respective valve bodies (16) incorporated in the head (9); the inlets (11) of all the cylinders (10) being closed by a single cover (33) fixed to the head (9).

A high pressure pump for complex injection engines is provided. A body of the high pressure pump includes a first flow path that transports the low pressure fuel flowing in through the low pressure fuel inlet and a low pressure fuel storage chamber that is disposed in a lower portion of the body to store the low pressure fuel transported from the first flow path. A second flow path transports the low pressure fuel stored in the low pressure fuel storage chamber and a flow control valve is disposed over the low pressure fuel storage chamber to discharge the low pressure fuel, transported through the second flow path, to the pressure unit or the damper disposed in an upper portion of the body based on an opening or closing operation. A low pressure fuel outlet discharges the low pressure fuel, transported through the damper, to a low pressure fuel rail.

A high pressure pump for complex injection engines is provided. A body of the high pressure pump includes a first flow path that transports the low pressure fuel flowing in through the low pressure fuel inlet and a low pressure fuel storage chamber that is disposed in a lower portion of the body to store the low pressure fuel transported from the first flow path. A second flow path transports the low pressure fuel stored in the low pressure fuel storage chamber and a flow control valve is disposed over the low pressure fuel storage chamber to discharge the low pressure fuel, transported through the second flow path, to the pressure unit or the damper disposed in an upper portion of the body based on an opening or closing operation. A low pressure fuel outlet discharges the low pressure fuel, transported through the damper, to a low pressure fuel rail.

A fuel supply device includes an injector, a fuel pressurization device and an ECU. The fuel pressurization device includes an electromagnetic valve. The fuel pressurization device is configured to pressurize a fuel in accordance with opening/closing of the electromagnetic valve and discharge the fuel toward the injector. The ECU is configured: to control the opening/closing of the electromagnetic valve to adjust the fuel amount discharged toward the injector; to execute an operation sound suppression control during a low-load operation of an engine by reducing an opening/closing frequency of the electromagnetic valve and increasing the fuel amount discharged for each opening/closing of the electromagnetic valve; not to execute the operation sound suppression control when a partial lift injection is in progress; and to execute the operation sound suppression control when the partial lift injection is not in progress.

A fuel pump includes a cylinder that forms a compression chamber which pressurizes a fuel, a plunger that compresses the fuel in the compression chamber, a cam that pushes the plunger, and a driven gear that engages a driving gear to transmit a rotational driving force. A profile of the cam is configured such that a peak arrival range is half or less of a compression range. Cam speed is obtained by differentiating a lift amount of the plunger by a rotation angle of the cam, the compression range is an angle range during which the plunger is pushed in the direction of compressing the fuel, and the peak arrival range is an angle range from a start of the compression range until a most retarded position of a peak of the cam speed.

A high pressure fuel supply pump includes: an electromagnetic suction valve that adjusts an amount of fuel sucked into a pressuring chamber; a discharge valve that discharges the fuel from the pressuring chamber; and a plunger that makes a reciprocating motion in the pressuring chamber. The electromagnetic suction valve includes an electromagnetic coil, a suction valve, and a movable portion that is able to close the suction valve by a magnetic force when the electromagnetic coil is energized. The movable portion includes an anchor that is driven to close the suction valve by the magnetic force and stops at a fixed member, and a rod that is driven with the anchor and is able to move even after the anchor stops. The electromagnetic suction valve includes a first and second springs that bias the suction valve in closed and open direction, respectively, and a third spring in the rod.

The error diagnosis device has: an input unit that receives detected values for pressure inside the common rail; a calculation unit that, if the detected values are less than a target common rail pressure, calculates the pressure differences and the fuel pump discharge amounts; and a determination unit that determines whether or not a set time has lapsed in a state in which the pressure differences are at least a first threshold value and less than a second threshold value and the discharge amounts are at least a third threshold value and less than a fourth threshold value. The determination unit determines that an error has occurred in the high-pressure pump if the set time has lapsed and determines that an error has occurred in the flowrate adjustment valve if the set time has not lapsed.

A discharge valve of a high-pressure pump is placed in a discharge passage and is openable to enable flow of fuel from a pressurizing chamber to a discharge outlet in response to a fuel pressure difference between the pressurizing chamber side and the discharge outlet side. A relief is placed in a relief passage. The relief passage communicates between a branching portion, which is located on a side of the discharge valve where the discharge outlet is placed in the discharge passage, and a return portion, which merges with a damper chamber. The relief valve is openable to enable flow of the fuel from the branching portion to the return portion in response to a fuel pressure difference between the branching portion side and the return portion side. A discharge passage orifice is placed between the discharge valve and the branching portion in the discharge passage and constricts a flow passage cross-sectional area of the discharge passage.