Valve timing controller and valve timing control method

Patent metadata

Field	Value
Publication number	US-2020200055-A1
Application number	US-201916718768-A
Country	US
Kind code	A1
Filing date	Dec 18, 2019
Priority date	Dec 21, 2018
Publication date	Jun 25, 2020
Grant date	—

Abstract

A valve timing controller for controlling a valve timing of an intake valve that opens and closes by a rotation of a camshaft to which a power is supplied from a crankshaft of an internal-combustion engine. The valve timing controller includes a phase changer changing a rotation phase for an adjustment of the valve timing; an electric actuator driving the phase changer; and a control section controlling an operation of the electric actuator, in which the control section performs a start time control process, controlling the valve timing to a rotation starter phase retarded from a preset reference phase at a start of crankshaft rotation, and controlling the valve timing to an engine started phase advanced therefrom after a passing of a top dead center in a first compression process by a piston in a cylinder after the start of crankshaft rotation and before completion of engine start.

First claim

What is claimed is:

1 . A valve timing controller for controlling a valve timing of an intake valve that opens and closes by a rotation of a camshaft to which a power is supplied from a crankshaft of an internal-combustion engine, the valve timing controller comprising:
a phase changer configured to change a rotation phase of the camshaft relative to the crankshaft for an adjustment of the valve timing; an electric actuator configured to drive the phase changer; and a control section configured to control an operation of the electric actuator, wherein the control section performs a start time control process, controlling the valve timing to a rotation starter phase that is set as retarded from a preset reference phase at a start of crankshaft rotation, and controlling the valve timing to an engine started phase that is set as advanced from the rotation starter phase after a passing of a top dead center in a first compression process by a piston in a cylinder after the start of crankshaft rotation and before completion of engine start.

2 . The valve timing controller of claim 1 , wherein
the control section obtains temperature of the internal-combustion engine, and performs the star time control process when the obtained temperature is equal to or lower than a predetermined threshold temperature indicative of a low temperature state.

3 . The valve timing controller of claim 1 , wherein
the rotation starter phase is set as a phase having an angle close to a most retarded angle.

4 . The valve timing controller of claim 1 , wherein
the control section identifies, in the start time control process, a top dead center passing timing by utilizing a voltage value that is applied to a terminal of at least one of a battery that supplies electric power to a starter motor and a device connected to the battery.

5 . The valve timing controller of claim 4 , wherein
the terminal of at least one of the battery and the device is a terminal of an electric actuator.

6 . The valve timing controller of claim 4 , wherein
the terminal of at least one of the battery and the device is a terminal of a starter motor.

7 . The valve timing controller of claim 4 , wherein
the control section identifies, as the top dead center passing timing, a timing of detecting a minimum voltage value for a second time in the start time control process.

8 . The valve timing controller of claim 1 , wherein
the control section controls, in the start time control process, the valve timing to the engine started phase during a period between (i) a first piston top dead center passing timing, which is a timing at which a first piston of a first cylinder that firstly performs the first compression process among a plurality of cylinders in the internal-combustion engine after the start of crankshaft rotation passes the top dead center of the first compression process, and (ii) a second piston top dead center passing timing at which a second piston of a second cylinder that secondly performs the first compression process among the plurality of cylinders in the internal-combustion engine after the start of crankshaft rotation passes the top dead center of the first compression process.

9 . A method for controlling a valve timing of an intake valve that opens and closes by a rotation of a camshaft to which a power is transmitted from a crankshaft in an internal-combustion engine, the control of the valve timing performed by controlling an operation of an electric actuator driving a phase changer that is capable of changing a rotation phase of the camshaft relative to the crankshaft, the method comprising:
controlling the valve timing to a rotation starter phase that is set as retarded from a reference phase at a start of crankshaft rotation; and controlling the valve timing to an engine started phase that is set as advanced from the rotation starter phase after a passing of a top dead center in a first compression process by a piston in a cylinder after the start of crankshaft rotation and before completion of engine start.

Assignees

• Denso Corp

Inventors

• Suzuki Genki
• Nakano Tomoaki

Classifications

• F02N19/004 Primary

  Aiding engine start by using decompression means or variable valve actuation · CPC title

• F02N2200/023

  Engine temperature · CPC title

• F02N11/00

  Starting of engines by means of electric motors · CPC title

• F02D2041/001

  for engines with variable valve actuation · CPC title

• F02N2200/063

  Battery voltage · CPC title