HIGH-PRESSURE PUMP CONTROL UNIT

• US 20170211558A1
• Filed: 10/18/2016
• Published: 07/27/2017
• Est. Priority Date: 01/21/2016
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: ZHANG, Chi
• Granted Patent: US 10,655,613 B2
• Time in Patent Office: Days
• CPC Class Codes: F02D 2041/2037 for preventing bouncing of the valve needle
• CPC Class Codes: F02D 2041/2058 using information of the actual current value
• CPC Class Codes: F02D 41/20 Output circuits, e.g. for controlling currents in command coils
• CPC Class Codes: F02D 41/3082 Control of electrical fuel pumps
• CPC Class Codes: F02D 41/3845 by controlling the flow into the common rail, e.g. the amount of fuel pumped
• CPC Class Codes: F02M 59/025 characterised by a single piston
• CPC Class Codes: F02M 59/102 Mechanical drive, e.g. tappets or cams F02M45/063 takes precedence
• CPC Class Codes: F02M 59/368 Pump inlet valves being closed when actuated
• CPC Class Codes: F04B 1/0408 Pistons
• CPC Class Codes: F04B 1/0426 Arrangements for pressing the pistons against the actuated cam; Arrangements for connecting the pistons to the actuated cam
• CPC Class Codes: F04B 1/0456 Cylindrical
• CPC Class Codes: F04B 1/053 with actuating or actuated elements at the inner ends of the cylinders
• CPC Class Codes: F04B 17/05 driven by internal-combustion engines
• CPC Class Codes: F04B 23/04 Combinations of two or more pumps
• CPC Class Codes: F04B 49/06 Control using electricity regulating by means of floats actuating electric switches F04B49/04
• CPC Class Codes: F04B 49/065 and making use of computers
• CPC Class Codes: F04B 53/001 Noise damping
• CPC Class Codes: F04B 53/10 Valves; Arrangement of valves
• CPC Class Codes: F04B 53/102 Disc valves
• CPC Class Codes: F04B 53/14 Pistons, piston-rods or piston-rod connections
• CPC Class Codes: F04B 7/0076 : the members being actuated by electro-magnetic means
• CPC Class Codes: F04B 9/042 : the means being cams

Abstract

When a condition for reducing a noise caused in the high-pressure pump is satisfied, a reduction control unit implements a noise reduction control to supply a smaller power to reduce a moving speed of a movable portion in a close acting direction to put a valve body into a closed state for a predetermined time after an energization start timing of a solenoid in a plunger rising period. A closing control unit causes a closing current, which is a constant current for surely putting the valve body into the closed state, to flow the closing current in the solenoid when the noise reduction control is completed in the plunger rising period. The predetermined time is shorter than an energization period in which a current flows in the solenoid.

Claims

1. A high-pressure pump control unit configured to control a high-pressure pump, the high-pressure pump including:

a pressurizing chamber having an intake port and a discharge port of fuel;

a plunger configured to move back and forth in the pressurizing chamber;

a valve body configured to open and close a fuel passage that is led to the intake port;

a first spring configured to urge the valve body in a closing direction to put the valve body into a closed state in which the valve body closes the fuel passage; and

an electromagnetic actuator configured to cause an opening and closing movement of the valve body, wherein the electromagnetic actuator includes a movable portion, which is urged by a second spring to bias the valve body in an opening direction opposite to the closing direction, and a solenoid, which is energized to draw the movable portion in a close acting direction, which is opposite to the direction in which the movable portion pushes the valve body, to put the valve body into the closed state, and

in a plunger rising period, in which the plunger rises from a bottom dead center to a top dead center, the solenoid is configured to be energized to put the valve body into the closed state and to discharge fuel in the pressurizing chamber from the discharge port, the high-pressure pump control unit comprising;

a reduction control unit configured, when a condition for reducing a noise caused in the high-pressure pump is satisfied, to implement a noise reduction control to supply a power smaller than a power, which is supplied when the condition is not satisfied, to reduce a moving speed of the movable portion in the close acting direction for a predetermined time after an energization start timing of the solenoid in the plunger rising period; and

a closing control unit configured, when the condition is satisfied, to cause a closing current, which is a constant current for surely putting the valve body into the closed state, to flow the closing current in the solenoid when the noise reduction control is completed in the plunger rising period, wherein

the predetermined time is shorter than an energization period in which a current flows in the solenoid.

2. The high-pressure pump control unit according to claim 1, further comprising:

an operation determination unit configured to determine whether the valve body is put into the closed state during a period in which the reduction control unit implements the noise reduction control; and

a determination unit configured to determine the closing current, which is caused to flow in the solenoid by the closing control unit, based on a previous determination result of the operation determination unit.

3. The high-pressure pump control unit according to claim 2, wherein

the determination unit is configured to determine the closing current based on a maximum value of the current flowing in the solenoid under a previous noise reduction control, when the previous determination result of the operation determination unit is a positive determination result that the valve body is put into the closed state, and

the determination unit is configured to determine the closing current based on the maximum value of the current under a recent noise reduction control that is positively determined by the operation determination unit, when the previous determination result of the operation determination unit is a negative determination result that the valve body is not put into the closed state.

4. The high-pressure pump control unit according to claim 3, wherein

the determination unit is configured to determine the closing current by multiplying the maximum value by a coefficient larger than 1.

5. The high-pressure pump control unit according to claim 2, wherein

the reduction control unit is configured to control an electric power to be supplied to the solenoid based on the previous determination result of the operation determination unit.

6. The high-pressure pump control unit according to claim 1, further comprising:

an operation determination unit configured to determine whether the valve body is put into the closed state during a period in which the reduction control unit implements the noise reduction control, wherein

the closing control unit is configured

to cause the closing current to flow in the solenoid when the operation determination unit makes a negative determination and

to stop the closing current from flowing in the solenoid when the operation determination unit makes a positive determination.

7. The high-pressure pump control unit according to claim 6, further comprising:

a current determination unit configured, when the operation determination unit makes the negative determination, to determine the closing current, which is caused to flow in the solenoid by the closing control unit, based on the maximum value of the current flowing in the solenoid under the recent noise reduction control in which the positive determination is made by the operation determination unit.

8. The high-pressure pump control unit according to claim 7, wherein

the current determination unit is configured to determine the closing current by multiplying a maximum value by a coefficient larger than 1.

9. The high-pressure pump control unit according to claim 6, wherein

the reduction control unit is configured to control an electric power to be supplied to the solenoid based on the previous determination result of the operation determination unit.