Method of starting a compression ignition engine

Patent metadata

Field	Value
Publication number	US-12497939-B2
Application number	US-202318861670-A
Country	US
Kind code	B2
Filing date	Apr 28, 2023
Priority date	May 25, 2022
Publication date	Dec 16, 2025
Grant date	Dec 16, 2025

Abstract

A method of starting a compression ignition engine is provided. The method comprises using a glow plug of the compression ignition engine to perform a warm up routine to preheat the compression ignition engine. During the warm up routine, a fuel rack actuator of the fuel rack is actuated which controls the quantity of fuel to be injected into the compression ignition engine such that the fuel rack is in a start-up fuel injection position by the end of the warm up routine. Following the end of the warm up routine, the compression ignition engine is cranked until the compression ignition engine starts, wherein the fuel rack actuator maintains the start-up fuel injection position of the fuel rack until the compression ignition engine has started.

First claim

The invention claimed is:

1 . A method of starting a compression ignition engine comprising:
using a glow plug of the compression ignition engine to perform a warm up routine to preheat the compression ignition engine; during the warm up routine, actuating a fuel rack actuator of a fuel rack which controls the quantity of fuel to be injected into the compression ignition engine such that the fuel rack is in a start-up fuel injection position by the end of the warm up routine; and following the end of the warm up routine, cranking the compression ignition engine until the compression ignition engine starts, wherein the fuel rack actuator maintains the start-up fuel injection position of the fuel rack until the compression ignition engine has started.

2 . The method of starting a compression ignition engine according to claim 1 , wherein
if a predetermined time period elapses after the end of the warm up routine without the compression ignition engine starting, the fuel rack actuator is moved to a minimum fuel injection position.

3 . The method of starting a compression ignition engine according to claim 1 , wherein
prior to performing the warm up routine, the fuel rack actuator is in a minimum fuel injection position.

4 . The method of starting a compression ignition engine according to claim 1 , wherein
the fuel rack actuator comprises a solenoid.

5 . The method of starting a compression ignition engine according to claim 1 , wherein
the start-up fuel injection position of the fuel rack is a maximum fuel injection position of the fuel rack.

6 . The method of starting a compression ignition engine according to claim 1 , wherein
the method is only performed when the temperature of the compression ignition engine is detected to be below a cold-start threshold.

7 . The method of starting a compression ignition engine according to claim 6 , wherein
the cold start threshold is about 0° C.

8 . The method of starting a compression ignition engine according to claim 1 , wherein
following the start of the compression ignition engine, the fuel rack actuator position is governed by a closed loop controller.

9 . A compression ignition engine controller configured to perform a start-up routine for a compression ignition engine, the controller configured to:
commence a warm-up routine by issuing a command to cause a glow plug of the compression ignition engine to preheat the compression ignition engine; during the warm-up routine, issue a command to actuate a fuel rack actuator of a fuel rack which controls the quantity of fuel to be injected into the compression ignition engine such that the fuel rack is in a start-up fuel injection position by the end of the warm up routine; and following the end of the warm up routine, issue a command to crank the compression ignition engine until the compression ignition engine starts, wherein the controller issues a command to maintain the start-up fuel injection position of the fuel rack until the compression ignition engine has started.

10 . The compression ignition engine controller according to claim 9 , wherein
following the end of the warm up routine, the controller is configured to wait to receive an input from an operator of the compression ignition engine controller before issuing the command to crank the compression ignition engine.

11 . The compression ignition engine controller according to claim 9 , wherein
if a predetermined time period elapses after the end of the warm up routine without the compression ignition engine starting, the compression ignition engine controller issues a command to move the fuel rack actuator to a minimum fuel injection position.

12 . The compression ignition engine controller according to claim 9 , wherein
the compression ignition engine controller only performs the start-up routine if the controller receives a signal that a temperature of the compression ignition engine is below a cold-start threshold.

13 . The compression ignition engine controller according to claim 12 , wherein
the cold start threshold is about −15° C.

14 . The compression ignition engine controller according to claim 9 , wherein
following the start of the compression ignition engine, the compression ignition engine controller is configured to govern the fuel rack actuator using a closed loop control strategy.

15 . The compression ignition engine controller according to claim 9 , wherein
the compression ignition engine controller only performs the start-up routine if the controller receives a signal indicative that the engine speed is zero and a signal indicative that the oil pressure is below a predetermined threshold.

16 . A compression ignition engine comprising:
a glow plug configured to heat the compression ignition engine; a fuel rack actuator configured to control the quantity of fuel to be injected into the compression ignition engine; and a compression ignition engine controller according to claim 9 .

Assignees

• Caterpillar Inc

Inventors

• Lloyd Thomas E
• Crawford Christopher J
• Ma Qiancheng

Classifications

• F02N19/04

  by heating of fluids used in engines · CPC title

• F02M31/13

  Combustion air · CPC title

• F02N19/06 Primary

  by heating of combustion-air by flame generating means, e.g. flame glow-plugs · CPC title

• F02D41/406

  Electrically controlling a diesel injection pump (F02D41/401 takes precedence) · CPC title

• F02N2019/002

  Aiding engine start by acting on fuel · CPC title