Control system of compression ignition type internal combustion engine

Patent metadata

Field	Value
Publication number	US-10190527-B2
Application number	US-201715591175-A
Country	US
Kind code	B2
Filing date	May 10, 2017
Priority date	May 17, 2016
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

An action of injection of the main injection fuel (QM) from the fuel injector (3) is started within a range of crank angle from 10 degree before the compression top dead center to 10 degree after the compression top dead center. A smaller amount of the auxiliary injection fuel (QN) than the main injection fuel (QM) is made to be injected from the fuel injector (3) before the main injection fuel (QM) so as to make the auxiliary injection fuel (QN) ignite by the premixed charge compression ignition. The injection timing of the auxiliary injection fuel (QN) is controlled to a timing whereby a heat generated by the premixed charge compression ignition of the auxiliary injection fuel (QN) causes the premixed charge compression ignition of the main injection fuel (QM) after the start of injection of the main injection fuel (QM).

First claim

The invention claimed is:

1. A control system of a compression ignition type internal combustion engine comprising a fuel injector arranged in a combustion chamber and an electronic control unit controlling a fuel injection action from the fuel injector, a main injection fuel injected from the fuel injector being ignited by a premixed charge compression ignition, wherein
said electronic control unit is configured to start an injection of the main injection fuel from the fuel injector within a range of crank angle from 10 degree before the compression top dead center to 10 degree after the compression top dead center and make a smaller amount of auxiliary injection fuel than the main injection fuel be injected from the fuel injector before the main injection fuel to ignite the auxiliary injection fuel by the premixed charge compression ignition,
said electronic control unit is further configured to control an injection timing of the auxiliary injection fuel to an injection timing whereby the premixed charge compression ignition of the main injection fuel is caused by a heat generated by the premixed charge compression ignition of the auxiliary injection fuel after a start of injection of the main injection fuel,
wherein a target compression ignition timing of the auxiliary injection fuel for causing the premixed charge compression ignition of the main injection fuel at a predetermined timing is set in advance between a time of the completion of injection of the main injection fuel and the compression top dead center or between a time of the start of injection of the main injection fuel and a time of the completion of injection of the main injection fuel, and
said electronic control unit is configured to determine the injection timing of the auxiliary injection fuel so that a time period from when the auxiliary injection fuel is injected to when a crank angle reaches said target compression ignition timing becomes constant.

2. The control system of a compression ignition type internal combustion engine as claimed in claim 1 , wherein the injection timing of the auxiliary injection fuel is advanced proportionally to an increase of engine speed.

3. The control system of a compression ignition type internal combustion engine as claimed in claim 1 , wherein the injection timing of the auxiliary injection fuel is advanced proportionally to an increase of the engine speed so that a rate of a premixed charge with an equivalent ratio of 1.0 to 2.0 in a premixed charge generated by the auxiliary injection fuel becomes maximum at said target compression ignition timing.

4. The control system of a compression ignition type internal combustion engine as claimed in claim 1 , wherein an exhaust gas recirculation device for recirculating exhaust gas to an intake passage is provided, and said electronic control unit is configured to control a recirculated amount of exhaust gas to control the premixed charge compression ignition timing of the auxiliary injection fuel to said target compression ignition timing.

5. The control system of a compression ignition type internal combustion engine as claimed in claim 1 , wherein cooling use fuel is injected at a predetermined crank angle after a completion of injection of the auxiliary injection fuel and before a start of injection of the main injection fuel when the engine speed is higher than a predetermined speed.

6. The control system of a compression ignition type internal combustion engine as claimed in claim 1 , wherein a swirl control device for controlling a swirl flow generated in an engine combustion chamber is provided, and the injection timing of the auxiliary injection fuel is retarded the more the swirl flow is strengthened.

7. The control system of a compression ignition type internal combustion engine as claimed in claim 1 , wherein said electronic control unit is configured to make the injection of the main injection fuel from the fuel injector be completed during a compression stroke before the compression top dead center and control the injection timing of the auxiliary injection fuel to an injection timing whereby the premixed charge compression ignition of the main injection fuel is caused by a heat generated by the premixed charge compression ignition of the auxiliary injection fuel after a completion of injection of the main injection fuel.

8. A control system of a compression ignition type internal combustion engine comprising a fuel injector arranged in a combustion chamber and an electronic control unit controlling a fuel injection action from the fuel injector, a main injection fuel injected from the fuel injector being ignited by a premixed charge compression ignition, wherein
said electronic control unit is configured to start an injection of the main injection fuel from the fuel injector within a range of crank angle from 10 degree before the compression top dead center to 10 degree after the compression top dead center and make a smaller amount of auxiliary injection fuel than the main injection fuel be injected from the fuel injector before the main injection fuel to ignite the auxiliary injection fuel by the premixed charge compression ignition,
said electronic control unit is further configured to control an injection timing of the auxiliary injection fuel to an injection timing whereby the premixed charge compression ignition of the main injection fuel is caused by a heat generated by the premixed charge compression ignition of the auxiliary injection fuel after a start of injection of the main injection fuel,
wherein a target compression ignition timing of the auxiliary injection fuel for causing the premixed charge compression ignition of the main injection fuel at a predetermined timing is set in advance between a time of the completion of injection of the main injection fuel and the compression top dead center or between a time of the start of injection of the main injection fuel and a time of the completion of injection of the main injection fuel, and
said electronic control unit is configured to control the injection timing of the auxiliary injection fuel to an injection timing at which the premixed charge compression ignition timing of the auxiliary injection fuel becomes said target compression ignition timing.

9. The control system of a compression ignition type internal combustion engine as claimed in claim 8 , wherein the injection timing of the auxiliary injection fuel is advanced proportionally to an increase of engine speed.

10. The control system of a compression ignition type internal combustion engine as claimed in claim 8 , wherein the injection timing of the auxiliary injection fuel is advanced proportionally to an increase of the engine speed so that a rate of a premixed charge with an equivalent ratio of 1.0 to 2.0 in a premixed charge generated by the auxiliary injection fuel becomes maximum at said target compression ignition timing.

11. The control system of a compression ignition type internal combustion engine as claimed in claim 8 , wherein an exhaust gas recirculation device for recirculating exhaust gas to an intake passage is provided, and said electronic control unit is configured to control a recirculated amount of exhaust gas to control the premixed charge compression ignition timing of the auxiliary injection fuel to said target compression ignition timing.

12. The control system of a compression ignition type internal combustion engine as claimed in claim 8 , wherein cooling use fuel is injected at a predetermined crank angle after a completion of injection of the auxiliary injection fuel and before a start of injection of the main injection fuel when the engine speed is higher than a predetermined

Assignees

• Toyota Motor Co Ltd

Inventors

• Shimizu Hajime
• Takada Noriyuki
• Takasu Yusuke

Classifications

• F02D2200/02

  the parameters being related to the engine · CPC title

• F02D41/401

  Controlling injection timing (F02D41/402 takes precedence) · CPC title

• F02D2041/389

  for injecting directly into the cylinder · CPC title

• F02D41/3047

  said means being a secondary injection of fuel · CPC title

• F02B9/04

  Methods of operating · CPC title