System and method for controlling valve timing of continuous variable valve duration engine

Patent metadata

Field	Value
Publication number	US-10634066-B2
Application number	US-201715839028-A
Country	US
Kind code	B2
Filing date	Dec 12, 2017
Priority date	Mar 16, 2016
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

A method for controlling intake and exhaust valves of an engine includes: controlling, by an intake continuous variable valve timing (CVVT) device, opening and closing timings of the intake valve; controlling, by an exhaust CVVT device, opening and closing timing of the exhaust valve; determining, by a controller, a target opening duration of the intake valve and target opening or target closing timings of the intake valve based on an engine load and an engine speed; modifying, by an intake continuous variable valve duration (CVVD) device, current opening and closing timings of the intake valve based on the target opening duration; and advancing or retarding, by the intake CVVD device, the current opening timing of the intake valve while simultaneously retarding or advancing the current closing timing of the intake valve by a predetermined value based on the target opening duration of the intake valve.

First claim

What is claimed is:

1. A method for controlling an intake valve and an exhaust valve of an engine, the method comprising:
controlling, by an intake continuous variable valve timing (CVVT) device, opening and closing timings of the intake valve;
controlling, by an exhaust CVVT device, opening and closing timing of the exhaust valve;
determining, by a controller, a target opening duration of the intake valve and at least one of a target opening timing or a target closing timing of the intake valve and the exhaust valve, based on an engine load and an engine speed;
classifying, by the controller, a plurality of control regions based on the engine load and engine speed, where the plurality of control regions includes a first control region where the engine load is between first and second predetermined loads, a second control region where the engine load is greater than the second predetermined load and equal to or less than a third predetermined load, a third control region, a fourth control region, a fifth control region, and a sixth control region;
modifying, by an intake continuous variable valve duration (CVVD) device, a current opening timing of the intake valve and a current closing timing of the intake valve based on the target opening duration of the intake valve;
advancing, by the intake CVVD device, the current opening timing of the intake valve while simultaneously retarding the current closing timing of the intake valve by a predetermined value and while maintaining a maximum amount of a valve lift of the intake valve at a same level, based on the target opening duration of the intake valve, or retarding the current opening timing of the intake valve while simultaneously advancing the current closing timing of the intake valve by a predetermined value and while maintaining the maximum amount of the valve lift of the intake valve at the same level, based on the target opening duration of the intake valve;
applying, by the controller, a maximum value of opening duration as the target opening duration to the intake valve in the first control region; and
maintaining, by the controller, the maximum value opening duration of the intake valve in the second control region and while increasing a valve overlap by retarding the closing timing of the exhaust valve in the second control region,
wherein the engine loads in the third, fourth, fifth and sixth control regions are greater than the third predetermined load.

2. The method of claim 1 , wherein the intake CVVD device advances the current opening timing of the intake valve while simultaneously retarding the current closing timing of the intake valve when the target opening duration of the intake valve is longer than a duration between the current opening timing and current closing timing of the intake valve.

3. The method of claim 1 , wherein the intake CVVD device retards the current opening timing of the intake valve while simultaneously advancing the current closing timing of the intake valve when the target opening duration of the intake valve is shorter than a duration between the current opening timing and current closing timing of the intake valve.

4. The method of claim 1 , further comprising the step of adjusting, by the intake CVVT device, the current opening and closing timings of the intake valve to the target opening and closing timings of the intake valve, respectively.

5. The method of claim 1 , wherein the valve overlap is increased by retarding the closing timing of the exhaust valve until the engine load reaches the third predetermined load and the valve overlap is reduced by advancing the closing timing of the exhaust valve when the engine load is increased over the third predetermined load.

6. The method of claim 1 , further comprising the step of advancing, by the intake CVVT device, the current closing timing of the intake valve to be approximately at a bottom dead center (BDC) when the engine speed is less than a first predetermined speed in the third control region; and advancing the current closing timing of the intake valve to an angle after the BDC when the engine speed is equal to or greater than the first predetermined speed in the third control region, wherein the third control region is where the engine load is greater than the third predetermined load and less than a fourth predetermined load and the engine speed is between the first predetermined speed and a second predetermined speed, or where the engine load is greater than the third predetermined load and equal to or less than a fifth predetermined load and the engine speed is between the second predetermined speed and a third predetermined speed.

7. The method of claim 1 , further comprising the step of controlling, by the intake CVVT device, the current opening timing of the intake valve to approximately at a top dead center (TDC) and the closing timing of the intake valve to approximately at a bottom dead center (BDC); and controlling, by the exhaust CVVT device, a current closing timing of the exhaust valve to be approximately at the TDC in the fourth control region where the engine load is greater than a fourth predetermined load and equal to or less than a fifth predetermined load and the engine speed is equal to or greater than a first predetermined speed and equal to or less than a second predetermined speed.

8. The method of claim 7 , further comprising the step of advancing, by the intake CVVT device, the current opening timing of the intake valve to an angle before a top dead center (TDC), and adjusting the current closing timing of the intake valve to an angle after a bottom dead center (BDC) in the fifth control region; and controlling, by the exhaust CVVT device, the closing timing of the exhaust valve to be an angle after the TDC in the fifth control region, wherein the fifth control region is where the engine load is greater than the fifth predetermined load and equal to or less than a maximum engine load and the engine speed is between the first and second predetermined speeds.

9. The method of claim 8 , further comprising the step of adjusting, by the exhaust CVVT device, the current closing timing of the exhaust valve to be approximately at a top dead center (TDC) so as to reduce a valve overlap in the sixth control region where the engine load is greater than the fifth predetermined load and equal to or less than the maximum engine load and the engine speed is greater than the second predetermined speed and equal to or less than a third predetermined speed.

10. A method for controlling an intake valve and an exhaust valve of an engine, the method comprising:
controlling, by an intake continuous variable valve timing (CVVT) device, opening and closing timings of the intake valve;
controlling, by an exhaust CVVT device, opening and closing timing of the exhaust valve;
determining, by a controller, a target opening duration of the intake valve and at least one of a target opening timing or a target closing timing of the intake valve, and based on an engine load and an engine speed;
classifying, by the controller, a plurality of control regions based on the engine load and engine speed, where the plurality of control regions includes a first control region where the engine load is between first and second predetermined loads, a second control region where the engine load is greater than the second predetermined load and equal to or less than a third predetermined load, a third control region, a fourth control region, a fifth control region, and a sixth control region;
modifying, by an intake continuous variable valve duration (CVVD) device, a current opening timing of the intake valve and a current closing timing of the intake valve based on the target opening duration

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Ryu In Sang
• Ha Kyoung Pyo
• Son You Sang
• Kwon Kiyoung

Classifications

• F02D2041/001

  for engines with variable valve actuation · CPC title

• F02D41/0007

  for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12) · CPC title

• F02D13/0207 Primary

  changing valve lift or valve lift and timing · CPC title

• F01L2001/0473

  Composite camshafts, e.g. with cams or cam sleeve being able to move relative to the inner camshaft or a cam adjusting rod · CPC title

• F02D2200/101

  Engine speed · CPC title