Three way catalytic control method and system for decreasing fuel consumption and vehicle having the same

Patent metadata

Field	Value
Publication number	US-9896988-B2
Application number	US-201615281545-A
Country	US
Kind code	B2
Filing date	Sep 30, 2016
Priority date	Dec 10, 2015
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

A three-way catalytic control method for reducing fuel consumption is provided. The method includes determining whether oxygen storage capacity of the three-way catalyst is under condition of increasing oxygen, when condition of performing O 2 purge control for the three-way catalyst is detected and performing O 2 purge control by applying a predetermined O 2 purge time period to which a set initial value of oxygen of OSC is applied, when the OSC is not under the condition of increasing oxygen. The O 2 purge control is performed by applying O 2 purge time period for a deteriorated product based on an oxygen sensor or O 2 purge time period for on board diagnosis, when an increase amount of the calculated O 2 purge time period is equal to or greater than the O 2 purge time period for the deteriorated product during the O 2 purge control.

First claim

What is claimed is:

1. A three-way catalytic control method for reducing fuel consumption, comprising:
determining, by a controller, whether Oxygen Storage Capacity (OSC) of the three-way catalyst is under a condition of increasing oxygen, when a condition of performing oxygen gas (O 2 ) purge control for the three-way catalyst is detected;
performing the O 2 purge control, by the controller, by applying a predetermined O 2 purge time period to which a set initial value (A) of oxygen of OSC is applied, when the OSC is not under the condition of increasing oxygen, and a calculated O 2 purge time period which is greater than the predetermined O 2 purge time period by applying an oxygen increase amount of OSC to the set initial value (A) of oxygen of OSC, when the OSC is under the condition of increasing oxygen; and
performing the O 2 purge control, by the controller, by applying an O 2 purge time period for a deteriorated product based on an oxygen sensor or an O 2 purge time period for On Board Diagnosis (OBD), when an increase amount of the calculated O 2 purge time period is equal to or greater than the O 2 purge time period for the deteriorated product during the O 2 purge control.

2. The method of claim 1 , wherein the condition of increasing oxygen of OSC is determined based on cycle variation of signal generated by the oxygen sensor disposed at a rear end side of the three-way catalyst and a frequency number that temperature of the catalyst, detected by a temperature sensor disposed in the three-way catalyst, exceeds a specific temperature.

3. The method of claim 1 , wherein the set initial value (A) of oxygen of OSC is greater than a predetermined amount of oxygen of OSC, in which OBD is reflected, for OBD monitoring of the three-way catalyst and less than an oxygen storage amount of OSC in a deteriorated product due to deterioration of the three-way catalyst.

4. The method of claim 1 , wherein the oxygen increase amount of OSC detects O 2 purge time period (x) reflecting deterioration based on the condition of increasing oxygen of OSC, calculates an oxygen increase amount (B) of OSC, to which the O 2 purge time period (x) reflecting deterioration is applied, calculates the current oxygen storage value (K) of OSC, to which the oxygen increase amount (B) of OSC is applied, compares an oxygen storage value (D) of OSC in a deteriorated product with the current oxygen storage value (K) of OSC during an O 2 purge time period (a) for a new product, an O 2 purge time period (b) for a deteriorated product, and an O 2 purge time period (c) for OBD, the new product and the deteriorated product indicating a degree of deterioration of the three-way catalyst, and calculates the O 2 purge time period using the current oxygen storage value (K) of OSC when the current oxygen storage value (K) of OSC is less than the oxygen storage value (D) of OSC in the deteriorated product.

5. The method of claim 4 , wherein the O 2 purge time period (x) reflecting deterioration is less than the O 2 purge time period (a) for the new product and greater than the O 2 purge time period (b) for the deteriorated product.

6. The method of claim 4 , wherein the increase amount (B) of oxygen of OSC is defined as B, B=(x−b)/(a−b)*A, wherein a is O 2 purge time period for the new product, b is O 2 purge time period for the deteriorated product, and A is a set initial value of oxygen of OSC.

7. The method of claim 4 , wherein the current oxygen storage value (K) of OSC is a value obtained by adding the set initial value (A) of oxygen of OSC to the oxygen increase amount (B) of OSC.

8. The method of claim 4 , wherein when the current oxygen storage value (K) of OSC is greater than the oxygen storage value (D) of OSC in the deteriorated product, the current oxygen storage value (K) is applied as the oxygen storage value (D) of OSC in the deteriorated product.

9. The method of claim 4 , wherein when the condition that the O 2 purge time period (x) reflecting deterioration is greater than the O 2 purge time period (b) for the deteriorated product and shorter than the O 2 purge time period (a) for the new product is not satisfied, or the current oxygen storage value (K) of OSC is greater than the oxygen storage value (D) of OSC in the deteriorated product and thus is applied to the oxygen storage value (D) of OSC in the deteriorated product, the O 2 purge time period (x) reflecting deterioration is compared with the O 2 purge time period (c) for OBD and then the O 2 purge time period for the deteriorated product or the O 2 purge time period for OBD is applied.

10. The method of claim 9 , wherein the O 2 purge time period for the deteriorated product is applied when the condition that the O 2 purge time period (x) reflecting deterioration is greater than the O 2 purge time period (c) for OBD and less than the O 2 purge time period (b) for the deteriorated product is satisfied.

11. The method of claim 1 , wherein the calculated O 2 purge time period is less than or equal to the O 2 purge time period for the deteriorated product, while the O 2 purge time period for the deteriorated product is greater than the O 2 purge time period (c) for OBD.

12. The method of claim 1 , wherein the O 2 purge control is performed when engine is idling after fuel-cut.

13. The method of claim 1 , wherein when the O 2 purge time period for OBD is applied, a warning light is turned on.

14. A three-way catalytic control system, comprising:
a controller including an oxygen gas (O 2 ) purge map allowing O 2 purge control for a three-way catalyst to apply a predetermined O 2 purge time period to which a set initial value (A) of oxygen of OSC (Oxygen Storage Capacity) is applied, when the OSC is not under the condition of increasing oxygen; to apply a calculated O 2 purge time period greater than the predetermined O 2 purge time period by applying an oxygen increase amount of OSC to the set initial value (A) of oxygen of OSC, when the OSC is under the condition of increasing oxygen; and to apply an O 2 purge time period for a deteriorated product based on an oxygen sensor or an O 2 purge time period for On Board Diagnosis (OBD), when an increase amount of the calculated O 2 purge time period is equal to or greater than the O 2 purge time period for the deteriorated product,
wherein the O 2 purge map is established as map data of information regarding oxygen storage of OSC based on a degree of deterioration of the three-way catalyst.

15. A vehicle, comprising:
a three-way catalytic control system in which oxygen gas (O 2 ) purge control for a three-way catalyst applies:
a predetermined O 2 purge time period to which a set initial value (A) of oxygen of Oxygen Storage Capacity (OSC) is applied, when the OSC is not under the condition of increasing oxygen;
a calculated O 2 purge time period which is greater than the predetermined O 2 purge time period by applying an oxygen increase amount of OSC to the set initial value (A) of oxygen of OSC, when the OSC is under the condition of increasing oxygen; and
an O 2 purge time period for a deteriorated product based on an oxygen sensor or an O 2 purge time period for On Board Diagnosis (OBD), when an increase amount of the calculated O 2 purge time period is equal to or greater than the O 2 purge time period for the deteriorated product,
wherein the three-way catalytic control system is connected with exhaust pipes through which exhaust gas emitted from an engine flows.

16. The vehicle of claim 15 , wherein the engine is a gasoline engine.

Assignees

• Hyundai Motor Co Ltd

Inventors

• Lee Sang Min

Classifications

• F01N3/22

  Control of additional air supply only, e.g. using by-passes or variable air pump drives · CPC title

• F01N3/101

  Three-way catalysts · CPC title

• F01N2560/025

  for measuring or detecting O2, e.g. lambda sensors · CPC title

• F01N3/0864

  Oxygen · CPC title

• F01N9/00 Primary

  Electrical control of exhaust gas treating apparatus (monitoring or diagnostic devices for exhaust-gas treatment apparatus F01N11/00; conjoint electrical control of two or more combustion engine functions F02D43/00) · CPC title