Four-stroke internal combustion engine and method of operating four-stroke internal combustion engine

Patent metadata

Field	Value
Publication number	US-11835010-B2
Application number	US-202017431186-A
Country	US
Kind code	B2
Filing date	Feb 17, 2020
Priority date	Feb 20, 2019
Publication date	Dec 5, 2023
Grant date	Dec 5, 2023

Abstract

Disclosed is a four-stroke direct injection engine comprising a camshaft, and exhaust valve, and a control system. The control system is configured to change the timing of the camshaft to advance a closing of the exhaust valve, control a first fuel injection step during a compression stroke of the piston, control a second fuel injection step during a power stroke of the piston, and control a third fuel injection step, after the second fuel injection step, during the power stroke of the piston.

First claim

The invention claimed is:

1. A method of controlling operation of a four-stroke direct injection internal combustion engine during regeneration of a particulate filter of an exhaust gas treatment system connected to the internal combustion engine, wherein said internal combustion engine comprises at least one cylinder arrangement, a crankshaft, and a camshaft, the cylinder arrangement comprising a combustion chamber, a fuel injector, an exhaust valve, a cylinder bore, and a piston configured to reciprocate in the cylinder bore and being connected to the crankshaft, wherein the camshaft is configured to control the opening and closing of the exhaust valve, wherein a timing of the camshaft is controllable, and wherein the method comprises the steps of:
a) adjusting the timing of the camshaft to advance a closing of the exhaust valve at least sixty (60) crankshaft angle degrees;
b) controlling the fuel injector to inject fuel into the cylinder bore during a compression stroke of the piston within a range of −40 to −15 crankshaft angle degrees in relation to zero (0) crankshaft angle degrees being at top dead center fire; and
c) controlling the fuel injector to inject fuel into the cylinder bore three separate instances during a power stroke of the piston as follows:
controlling the fuel injector to inject fuel into the cylinder bore at a first instance after the power stroke of the piston has been initiated;
controlling the fuel injector to inject fuel into the cylinder bore at a second instance after the first instance and within a range of 30 to 50 degrees crankshaft angle in relation to zero (0) crankshaft angle degrees being at top dead center fire; and
controlling the fuel injector to inject fuel into the cylinder bore at a third instance after the second instance and after an opening of the exhaust valve during the power stroke,

wherein the combination of controlling the fuel injector to inject fuel at steps b) thru c), while controlling the timing of the camshaft to advance closing of the exhaust valve in step a) thereby causes at least one of an increase in: (i) a temperature of an exhaust gas exiting the internal combustion engine, or (ii) a content of nitrogen oxide in the exhaust gas.

2. The method according to claim 1 , wherein step b) comprises controlling the fuel injector to perform at least one additional fuel infection during the compression stroke of the piston.

3. The method according to claim 1 , wherein the internal combustion engine comprises an exhaust gas aftertreatment system, which comprises a first selective catalytic reduction device and downstream thereof a particulate filter, and wherein the method further comprises:
refraining from injection of urea or ammonia into the first selective catalytic reduction device.

4. A four-stroke direct injection internal combustion engine comprising at least one cylinder arrangement, a crankshaft, a camshaft, and a control system, wherein the cylinder arrangement comprises a combustion chamber, a fuel injector, an exhaust valve, a cylinder bore, and a piston configured to reciprocate in the cylinder bore and being connected to the crankshaft, wherein the fuel injector is controllable by the control system, wherein the camshaft is configured to control the opening and closing of the exhaust valve, wherein a timing of the camshaft is controllable by the control system, and wherein the control system is configured to perform the following steps during regeneration of a particulate filter of an exhaust gas treatment system connected to the internal combustion engine:
a) adjust the timing of the camshaft to advance a closing of the exhaust valve at least sixty (60) crankshaft angle degrees;
b) control the fuel injector to inject fuel into the cylinder bore during a compression stroke of the piston within a range of −40 to −15 crankshaft angle degrees in relation to zero (0) crankshaft angle degrees being at top dead center fire; and
c) control the fuel injector to inject fuel into the cylinder bore three separate instances during a power stroke of the piston as follows:
control the fuel injector to inject fuel into the cylinder bore at a first instance after the power stroke of the piston has been initiated;
control the fuel injector to inject fuel into the cylinder bore at a second instance after the first instance and within a range of 30 to 50 degrees crankshaft angle in relation to zero (0) crankshaft angle degrees being at top dead center fire; and
control the fuel injector to inject fuel into the cylinder bore at a third instance after the second instance and after an opening of the exhaust valve during the power stroke,

wherein the combination of controlling the fuel injector to inject fuel at steps b) thru c), while controlling the timing of the camshaft to advance closing of the exhaust valve in step a) thereby causes at least one of an increase in: (i) a temperature of an exhaust gas exiting the internal combustion engine, or (ii) a content of nitrogen oxide in the exhaust gas.

5. The internal combustion engine according to claim 4 , wherein step b) controlling the fuel injector to perform at least one additional fuel injection during the compression stroke of the piston.

6. The internal combustion engine according to claim 4 , comprising an exhaust gas aftertreatment system, which comprises a first selective catalytic reduction device and downstream thereof a particulate filter, and wherein the control system is further configured to refrain from injection of ammonia into the first selective catalytic reduction device.

7. A vehicle comprising a four-stroke direct injection internal combustion engine comprising at least one cylinder arrangement, a crankshaft, a camshaft, and a control system, wherein the cylinder arrangement comprises a combustion chamber, a fuel injector, an exhaust valve, a cylinder bore, and a piston configured to reciprocate in the cylinder bore and being connected to the crankshaft, wherein the fuel injector is controllable by the control system, wherein the camshaft is configured to control the opening and closing of the exhaust valve, wherein a timing of the camshaft is controllable by the control system, and wherein the control system is configured to perform the following steps during regeneration of a particulate filter of an exhaust gas treatment system connected to the internal combustion engine:
a) adjust the timing of the camshaft to advance a closing of the exhaust valve at least sixty (60) crankshaft angle degrees;
b) control the fuel injector to inject fuel into the cylinder bore during a compression stroke of the piston within a range of −40 to −15 crankshaft angle degrees in relation to zero (0) crankshaft angle degrees being at top dead center fire; and
c) control the fuel injector to inject fuel into the cylinder bore three separate instances during a power stroke of the piston as follows:
control the fuel injector to inject fuel into the cylinder bore at a first instance after the power stroke of the piston has been initiated;
control the fuel injector to inject fuel into the cylinder bore at a second instance after the first instance and within a range of 30 to 50 degrees crankshaft angle in relation to zero (0) crankshaft angle degrees being at top dead center fire; and
control the fuel injector to inject fuel into the cylinder bore at a third instance after the second instance and after an opening of the exhaust valve during the power stroke,

wherein the combination of controlling the fuel injector to inject fuel at steps b) thru c), while controlling the timing of the camshaft to advance closing of the exhaust valve in step a) thereby causes at least one of an increase in: (i) a temperature of an exhaust gas exiting the internal combustion engine, or (ii) a

Assignees

• Scania Cv Ab

Inventors

• Dahl Andreas
• Vallinder Michael

Classifications

• F02D41/402 Primary

  Multiple injections · CPC title

• F02D13/0249

  changing the valve timing only · CPC title

• F02D41/009

  using means for generating position or synchronisation signals · 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

• F01N3/023 Primary

  using means for regenerating the filters, e.g. by burning trapped particles · CPC title