Method for controlling variable valve lift apparatus and variable valve lift system

Patent metadata

Field	Value
Publication number	US-9447738-B2
Application number	US-201314144357-A
Country	US
Kind code	B2
Filing date	Dec 30, 2013
Priority date	Oct 24, 2013
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

A method for controlling a variable valve lift apparatus includes: measuring an operation mode switching condition; determining whether the variable valve lift apparatus is in a normal operation condition; controlling the operation of the variable valve lift apparatus depending on a predetermined normal valve lift switching map; determining whether the variable valve lift apparatus is in a mode switching delay or switching disable condition from a high lift mode to a low lift mode or whether the variable valve lift apparatus is in the mode switching delay or switching disable condition from the low lift mode to the high lift mode; controlling the operation of the variable valve lift apparatus depending on a predetermined low oil temperature valve lift switching map; and controlling the operation of the variable valve lift apparatus depending on a predetermined high oil temperature valve lift switching map.

First claim

What is claimed is:

1. A method for controlling a variable valve lift apparatus, comprising:
measuring an operation mode switching condition of the variable valve lift apparatus;
determining, by a controller, whether the variable valve lift apparatus is in a normal operation condition based on the measured operation mode switching condition wherein the normal operation condition is a predetermined condition in which the variable valve lift apparatus is to be operated without a mode switching delay or a switching disable condition,
wherein the mode switching delay is a condition including a predetermined oil pressure or oil temperature at which the switching of the valve variable lift apparatus from high lift mode to low lift mode or the low lift mode to the high lift mode is delayed than the switching in the normal operation condition, and wherein the mode switching disable condition is a condition including a predetermined oil pressure or oil temperature at which the switching of the valve variable lift apparatus from high lift mode to low lift mode or the low lift mode to the high lift mode is disabled;
controlling, by the controller, operation of the variable valve lift apparatus based on a predetermined normal valve lift switching map if it is determined that the variable valve lift apparatus satisfies the normal operation condition wherein the predetermined normal valve lift switching map includes a predetermined switching mode between the low lift mode and the high lift mode;
determining, by the controller, whether the variable valve lift apparatus is in the mode switching delay or the switching disable condition from the high lift mode to the low lift mode or whether the variable valve lift apparatus is in the mode switching delay or the switching disable condition from the low lift mode to the high lift mode, if it is determined that the variable valve lift apparatus does not satisfy the normal operation condition;
controlling, by the controller, the operation of the variable valve lift apparatus based on a predetermined low oil temperature valve lift switching map when the variable valve lift apparatus is in the mode switching delay or the switching disable condition from the high lift mode to the low lift mode;
controlling, by the controller, the operation of the variable valve lift apparatus depending on a predetermined high oil temperature valve lift switching map when the variable valve lift apparatus is in the mode switching delay or the switching disable condition from the low lift mode to the high lift mode;
controlling, by the controller, an air content control valve which controls an air content introduced into the engine to increase the introduced air content, when the variable valve lift apparatus is in the mode switching delay or the switching disable condition from the low lift mode to the high lift mode; and
controlling, by the controller, an injector to reduce an injected fuel amount, when the variable valve lift apparatus is in the mode switching delay or the switching disable condition from the high lift mode to the low lift mode.

2. The method of claim 1 , wherein the low oil temperature valve lift switching map includes a set first engine RPM which switches the variable valve lift apparatus from the high lift mode to the low lift mode depending on the measured operation mode switching condition when a temperature of oil supplied to the variable valve lift apparatus is lower than a predetermined value.

3. The method of claim 2 , wherein the high oil temperature valve lift switching map includes a set second engine RPM larger than the first engine RPM which switches the variable valve lift apparatus from the low lift mode to the high lift mode depending on the measured operation mode switching condition when the temperature of the oil supplied to the variable valve lift apparatus is equal to or higher than the predetermined value.

4. The method of claim 1 , wherein the operation mode switching condition includes a set oil temperature condition and oil pressure condition.

5. The method of claim 4 , wherein the oil temperature is predicted by measuring a cooling water temperature.

6. The method of claim 4 , wherein the operation mode switching condition further includes at least any one of atmospheric temperature, atmospheric pressure, and atmospheric humidity.

7. A variable valve lift system, comprising:
an engine including a variable valve lift apparatus, an air content control valve controlling an introducing air content, an engine RPM sensor, and an injector;
an oil pressure sensor configured to measure an oil pressure to output a corresponding signal;
a cooling water temperature sensor configured to measure a cooling water temperature to output a corresponding signal;
a memory configured to store a normal valve lift switching map which switches an operation mode of the variable valve lift apparatus when the variable valve lift apparatus is in a normal operation condition, a low oil temperature valve lift switching map which switches the operation mode of the variable valve lift apparatus when the variable valve lift apparatus is in a mode switching delay or a switching disable condition from a high lift mode to a low lift mode, and a high oil temperature valve lift switching map which switches the operation mode of the variable valve lift apparatus when the variable valve lift apparatus is in the mode switching delay or the switching disable condition from the low lift mode to the high lift mode
wherein the normal operation condition is a predetermined condition in which the variable valve lift apparatus is to be operated without the mode switching delay or the switching disable condition,
wherein the mode switching delay is a condition including a predetermined oil pressure or oil temperature at which the switching of the valve variable lift apparatus from the high lift mode to the low lift mode or the low lift mode to the high lift mode is delayed than the switching in the normal operation condition, and wherein the mode switching disable condition is a condition including a predetermined oil pressure or oil temperature at which the switching of the valve variable lift apparatus from the high lift mode to the low lift mode or the low lift mode to the high lift mode is disabled, and
wherein the normal valve lift switching map includes a predetermined switching mode between a low lift mode and a high lift mode; and
a controller configured to receive the corresponding signal from the oil pressure sensor, the cooling water temperature sensor, and a corresponding signal of the engine RPM sensor to determine a currently available valve lift switching map among the valve lift switching maps from the memory and control the operation of the variable valve lift apparatus depending on the determined corresponding valve lift switching map,
wherein the controller controls the operation of the air content control valve to increase the air content introducing into the engine when the variable valve lift apparatus is controlled depending on the high oil temperature lift switching map, and
wherein the controller controls the operation of the injector to reduce the fuel amount injected to the engine when the variable valve lift apparatus is controlled depending on the low oil temperature lift switching map.

Assignees

• Hyundai Motor Co Ltd

Inventors

• Lee Jang Su
• Yu Jun
• Kim Keun Sang
• Lee Hyeungwoo

Classifications

• F01L1/34

  characterised by the provision of means for changing the timing of the valves without changing the duration of opening {and without affecting the magnitude of the valve lift} · CPC title

• F02D41/30

  Controlling fuel injection {(F02D41/182, F02D41/24 take precedence)} · CPC title

• Y02T10/18

  Cross-Sectional Technologies · mapped topic

• F02D41/0002

  Controlling intake air · CPC title

• F02D13/0207 Primary

  changing valve lift or valve lift and timing · CPC title