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Direct injection type engine

Imported: 24 Feb '17 | Published: 06 Jan '04

Hiroki Murata, Shizuo Sasaki, Kohei Igarashi

USPTO - Utility Patents

Abstract

A direct injection type engine comprising a variable speed transmission. Engine control lines indicating the relationship between the engine rotational speed and required torque necessary for obtaining a required output are comprised of a first control line and a second control line at the high torque side and low speed side of the first control line. When the degree of activation of the exhaust gas purification device is low, the required torque and the engine rotational speed are made ones on the first control line in accordance with the required output, while when the degree of activation is high, the required torque and the engine rotational speed are made ones on the second control line in accordance with the required output.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may be more fully understood from the description of the preferred embodiments of the invention set forth below together with the accompanying drawings, in which:

FIG. 1 is an overall view of a compression ignition type engine;

FIG. 2 is a side sectional view of the engine body;

FIG. 3 is an overall view of another embodiment of a compression ignition type engine;

FIGS. 4A and 4B are views of maps of the target amount of intake air;

FIG. 5 is a view of a map of the predicted reference opening degree;

FIGS. 6A and 6B are views of a particulate filter;

FIGS. 7A and 7B are views for explaining an oxidation action of particulate;

FIGS. 8A to

8C are views for explaining a deposition action of particulate;

FIG. 9 is a view of the relationship between the amount of particulate removable by oxidation and the temperature of the particulate filter;

FIG. 10 is a view of a particulate and NO

x simultaneous processing region;

FIG. 11 is a view of a required torque;

FIG. 12 is a view of engine control lines;

FIG. 13 is a flow chart of the control of a changeover flag;

FIG. 14 is a flow chart of operational control;

FIG. 15 is a view of the required torque;

FIG. 16 is a view of gear boundary lines;

FIG. 17 is a flow chart of operational control;

FIG. 18 is a view of a map of the amount of NO

x absorption;

FIG. 19 is a flow chart of processing for NO

x and SO

x release flags;

FIG. 20 is a flow chart of processing for release of NO

x and SO

x;

FIG. 21 is a flow chart of acceleration/deceleration processing; and

FIG. 22 is a view of the output torque of an electric motor.

Claims

1. A direct injection type engine provided with an exhaust passage, comprising:

2. A direct injection type engine as set forth in claim 1, wherein said exhaust gas purification device is comprised of a particulate filter able to remove by oxidation particulate in an exhaust gas and having the function of absorbing NO

x in the exhaust gas when the air-fuel ratio of the inflowing exhaust gas is lean and releasing the absorbed NO

x when the air-fuel ratio of the inflowing exhaust gas is the stoichiometric air-fuel ratio or rich, and it is judged that the extent of activation of the exhaust gas purification device is high when it is estimated that an amount of particulate deposited on the particulate filter is less than a predetermined amount and a temperature of the particulate filter is in a temperature range giving an NO

x absorption rate of more than a certain value.

3. A direct injection type engine as set forth in claim 2, wherein as said particulate filter, use is made of a particulate filter able to remove by oxidation any particulate in the exhaust gas flowing into the particulate filter without emitting a luminous flame when an amount of discharged particulate discharged from the combustion chamber per unit time is smaller than an amount of particulate which can be removed by oxidation without emitting a luminous flame per unit time on the particulate filter.

4. A direct injection type engine as set forth in claim 3, wherein a precious metal catalyst is carried on the particulate filter.

5. A direct injection type engine as set forth in claim 4, wherein an active oxygen release agent, taking in oxygen and holding the oxygen when excess air exists in the surroundings and releasing the held oxygen in the form of active oxygen when a concentration of oxygen in the surroundings falls, is carried on the particulate filter, and active oxygen is released from the active oxygen release agent when particulate deposits on the particulate filter, particulate deposited on the particulate filter being oxidized by the released active oxygen.

6. A direct injection type engine as set forth in claim 3, wherein the air-fuel ratio of the exhaust gas flowing into the particulate filter is made temporarily rich when NO

x should be released from the particulate filter.

7. A direct injection type engine as set forth in claim 6, wherein the air-fuel ratio of the exhaust gas flowing into the particulate filter is made rich over a longer time than a time of release of NO

x from the particulate filter when SO

x should be released from the particulate filter.

8. A direct injection type engine as set forth in claim 1, wherein judging means is provided for judging if particulate has deposited to more than a certain extent on the particulate filter, said control means changing the control of the torque generated by the engine and the gear ratio of the variable speed transmission from control based on the second control line to control based on the first control line when it is judged that the particulate has deposited to more than a certain extent on the particulate filter when controlling the torque generated by the engine and the gear ratio of the variable speed transmission based on the second control line.

9. A direct injection type engine as set forth in claim 8, wherein intake air amount control means for controlling the amount of intake air to a target amount of intake air is provided, and an exhaust gas recirculation control valve for controlling the amount of recirculated exhaust gas recirculated in the intake passage of the engine is provided, said judging means judging that the particulate on the particulate filter has deposited to more than a certain extent when an opening degree of the exhaust gas recirculation control valve has become smaller than a predetermined opening degree when an amount of intake air is controlled to the target amount of intake air.

10. A direct injection type engine provided with an exhaust passage, comprising:

11. A direct injection type engine as set forth in claim 10, wherein the fuel economy is better, but the amount of harmful components in the exhaust gas becomes greater when changing the speeds at the second boundary lines than when changing the speeds at the first boundary lines.

12. A direct injection type engine as set forth in claim 10, wherein said exhaust gas purification device is comprised of a particulate filter able to remove by oxidation particulate in the exhaust gas and having the function of absorbing NO

x in the exhaust gas when the air-fuel ratio of the inflowing exhaust gas is lean and releasing the absorbed NO

x when the air-fuel ratio of the inflowing exhaust gas is the stoichiometric air-fuel ratio or rich, and it is judged that the extent of activation of the exhaust gas purification device is high when it is estimated that an amount of particulate deposited on the particulate filter is less than a predetermined amount and a temperature of the particulate filter is in a temperature range giving an NO

x absorption rate of more than a certain value.

13. A direct injection type engine as set forth in claim 12, wherein as said particulate filter, use is made of a particulate filter able to remove by oxidation any particulate in the exhaust gas flowing into the particulate filter without emitting a luminous flame when an amount of discharged particulate discharged from the combustion chamber per unit time is smaller than an amount of particulate which can be removed by oxidation without emitting a luminous flame per unit time on the particulate filter.

14. A direct injection type engine as set forth in claim 13, wherein a precious metal catalyst is carried on the particulate filter.

15. A direct injection type engine as set forth in claim 14, wherein an active oxygen release agent, taking in oxygen and holding the oxygen when excess air exists in the surroundings and releasing the held oxygen in the form of active oxygen when the concentration of oxygen in the surroundings falls, is carried on the particulate filter, and active oxygen is released from the active oxygen release agent when particulate deposits on the particulate filter, particulate deposited on the particulate filter being oxidized by the released active oxygen.

16. A direct injection type engine as set forth in claim 12, wherein the air-fuel ratio of the exhaust gas flowing into the particulate filter is made temporarily rich when NO

x should be released from the particulate filter.

17. A direct injection type engine as set forth in claim 16, wherein the air-fuel ratio of the exhaust gas flowing into the particulate filter is made rich over a longer time than a time of release of NO

x from the particulate filter when SO

x should be released from the particulate filter.