Method and control apparatus for controlling a high-pressure fuel supply pump configured to supply pressurized fuel to an internal combustion engine

Patent metadata

Field	Value
Publication number	US-9273625-B2
Application number	US-201113293556-A
Country	US
Kind code	B2
Filing date	Nov 10, 2011
Priority date	Nov 12, 2010
Publication date	Mar 1, 2016
Grant date	Mar 1, 2016

Abstract

The present invention relates to a method and an apparatus for controlling a high-pressure fuel supply pump configured to supply pressurized fuel to an internal combustion engine, with a solenoid-actuated intake valve being configured to be biased into a first direction towards a first stop position of the intake valve by means of a biasing force and being configured to be displaced against the biasing force into a second direction opposite to the first direction towards a second stop position of the intake valve by means of magnetic force and to be kept at the second stop position by means of magnetic force. The method includes applying control current to the solenoid-actuated intake valve for displacing the intake valve into the second direction to the second stop position and for keeping the intake valve at the second stop position during a first time period by means of magnetic force.

First claim

What is claimed is:

1. A method for controlling a high-pressure fuel supply pump configured to supply pressurized fuel to an internal combustion engine, the high-pressure fuel supply pump comprising a compression chamber, a solenoid-actuated intake valve configured to deliver unpressurized fuel to the compression chamber, a movable plunger reciprocating in the compression chamber between a first plunger position (BDC) and a second plunger position (TDC), the movable plunger pressurizing fuel in the compression chamber, and a discharge valve configured to discharge pressurized fuel from the compression chamber to be supplied to the internal combustion engine, the solenoid-actuated intake valve being configured to be biased into a first direction towards a first stop position by means of a biasing force and being configured to be displaced against the biasing force into a second direction opposite to the first direction towards a second stop position by means of a magnetic force and to be kept at the second stop position by means of the magnetic force, the method comprising:
applying a first control current to the solenoid-actuated intake valve, the first control current displacing the solenoid-actuated intake valve into the second direction to the second stop position during a first compression period in which the movable plunger moves upward;
subsequently shutting off the first control current but keeping the solenoid-actuated intake valve at the second stop position during the first compression period;
subsequently applying a second control current to the solenoid-actuated intake valve during an intake period in which the movable plunger moves downward, the intake period immediately following the first compression period; and,
subsequently decreasing the second control current being applied during the intake period down to zero, wherein
a peak of the first control current is larger than a peak of the second control current.

2. The method according to claim 1 , wherein
the solenoid-actuated intake valve is a normally-open-type solenoid-actuated intake valve being configured to be closed and/or kept closed by means of magnetic force, wherein the first stop position is a fully open position of the solenoid-actuated intake valve, the first direction is an opening direction of the solenoid-actuated intake valve, the second stop position is a fully closed position of the solenoid-actuated intake valve and the second direction is a closing direction of the solenoid-actuated intake valve; or
the solenoid-actuated intake valve is a normally-closed-type solenoid-actuated intake valve being configured to be opened and/or kept open by means of magnetic force, wherein the first stop position is a fully closed position of the solenoid-actuated intake valve, the first direction is a closing direction of the solenoid-actuated intake valve, the second stop position is a fully open position of the solenoid-actuated intake valve and the second direction is an opening direction of the solenoid-actuated intake valve.

3. The method according to claim 1 , wherein
the first control current to the solenoid-actuated intake valve is controlled by applying a pulse-width modulation voltage signal to the solenoid-actuated intake valve; and
gradually decreasing the second control current value by decreasing a duty cycle of the applied pulse-width modulation voltage signal; or
gradually decreasing the second control current value by continuously decreasing a duty cycle of the applied pulse-width modulation voltage signal.

4. The method according to claim 1 , wherein the solenoid-actuated intake valve is a normally-open-type solenoid-actuated intake valve being configured to be closed or kept closed by means of magnetic force; and
the operation of the high-pressure fuel supply pump comprises:
the intake period in which fuel is taken in through the solenoid-actuated intake valve into the compression chamber while the movable plunger moves from the second plunger position (TDC) to the first plunger position (BDC) and the solenoid-actuated intake valve opens or is kept open by means of a biasing force or by means of a biasing force and a hydraulic force,
a spill period in which fuel is spilled out of the compression chamber through the solenoid-actuated intake valve while the movable plunger moves from the first plunger position (BDC) to the second plunger position (TDC) and the solenoid-actuated intake valve is kept open by means of a biasing force, and
a delivery period in which fuel is pressurized in the compression chamber and discharged through the discharge valve to be supplied to the internal combustion engine while the movable plunger moves from the first plunger position (BDC) to the second plunger position (TDC) and the solenoid-actuated intake valve is kept closed by means of magnetic force.

5. The method according to claim 1 , wherein the solenoid-actuated intake valve is a normally-open-type solenoid-actuated intake valve being configured to be closed or kept closed by means of magnetic force; and
the operation of the high-pressure fuel supply pump comprises:
the intake period in which fuel is taken in through the solenoid-actuated intake valve, if the solenoid-actuated intake valve is kept open during the intake period, or through an auxiliary valve, if the solenoid-actuated intake valve is kept closed during the intake period by applying the first control current to the solenoid-actuated intake valve, into the compression chamber while the movable plunger moves from the second plunger position (TDC) to the first plunger position (BDC),
a delivery period in which fuel is pressurized in the compression chamber and discharged through the discharge valve to be supplied to the internal combustion engine while the movable plunger moves from the first plunger position (BDC) to the second plunger position (TDC) and the solenoid-actuated intake valve is kept closed by means of the magnetic force, and
a spill period in which fuel is spilled out of the compression chamber through the solenoid-actuated intake valve while the movable plunger moves from the first plunger position (BDC) to the second plunger position (TDC) and the solenoid- actuated intake valve opens or is kept open by means of a biasing force or by means of a biasing force and a hydraulic force, wherein
a time period of applying or decreasing the second control current is included in the spill period.

6. The method according to claim 1 , wherein
the second control current is applied to the solenoid-actuated intake valve during the intake period such that an acceleration of the movement of the solenoid-actuated intake valve into the first direction is prevented, prior to a time at which the solenoid-actuated intake valve reaches the first stop position, such that a movement of the solenoid-actuated intake valve into the first direction is decelerated, prior to a time at which the solenoid-actuated intake valve reaches the first stop position.

7. The method according to claim 1 , wherein
the second control current is applied in the intake period at least until the solenoid-actuated intake valve reaches the first stop position.

8. The method according to claim 1 , wherein
when the solenoid-actuated intake valve is a normally-open-type solenoid-actuated intake valve being configured to be closed or kept closed by means of magnetic force,
the second control current is applied before the movable plunger has reached the second plunger position (TDC);
the second control current is applied after the movable plunger has reached the second plunger position (TDC);
or the second control current is applied substantially at a time at which the movable plunger reaches the second plunger position (TDC).

Assignees

• Borg Jonathan
• Watanabe Masanori
• Dettmering Ulf
• Tokuo Kenichiro
• Hitachi Ltd

Inventors

• Borg Jonathan
• Watanabe Masanori
• Dettmering Ulf
• Tokuo Kenichiro

Classifications

• F02M59/466

  Electrically operated valves, e.g. using electromagnetic or piezoelectric operating means · CPC title

• F02M63/0225

  Fuel-injection apparatus having a common rail feeding several injectors (F02M63/0003 takes precedence); Means for varying pressure in common rails; Pumps feeding common rails · CPC title

• F02D41/20 Primary

  Output circuits, e.g. for controlling currents in command coils · CPC title

• F02D2041/2027

  Control of the current by pulse width modulation or duty cycle control · CPC title

• F02D2041/2037

  for preventing bouncing of the valve needle · CPC title