Method for operating an internal combustion engine

Patent metadata

Field	Value
Publication number	US-11519328-B2
Application number	US-201716954078-A
Country	US
Kind code	B2
Filing date	Dec 20, 2017
Priority date	Dec 20, 2017
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

The invention relates to a method ( 100 ) for operating an internal combustion engine ( 2 ), such as an internal combustion engine of a vehicle ( 1 ), the engine ( 2 ) comprising an engine cylinder ( 3 ) at least partly defining a combustion chamber ( 4 ) and a reciprocating piston ( 5 ), a number of inlet valves ( 20 ) in fluid communication with the combustion chamber and a number of exhaust valves ( 30 ) in fluid communication with the combustion chamber, wherein any one of the inlet valves and the outlet valves comprises at least one flow control valve. The method comprises the following steps: opening ( 105 ) at least one of the inlet valves and introducing the incoming fluid medium into the cylinder ( 3 ) of the engine by performing an intake stroke (S 1 ); compressing ( 110 ) the trapped incoming fluid medium in a first compression stroke (CS 1 ) of the cylinder ( 3 ), while having the number of the inlet valves and the number of the exhaust valves in a closed state; injecting ( 115 ) a quantity of fuel into the cylinder ( 3 ) and combusting said injected fuel; performing ( 120 ) a first work stroke (WS 1 ) to produce power to a crank shaft of the engine, while controlling said flow control valve to partly exhaust burnt gases at the end of the work stroke; additionally compressing ( 125 ) remaining fluid medium in an additional compression stroke (CS 2 ) of the cylinder ( 3 ), while having the number of the inlet valves and the number of the exhaust valves in a closed state; additionally injecting ( 130 ) an additional quantity of fuel into the cylinder ( 3 ); additionally performing ( 135 ) an additional work stroke (WS 2 ) to produce power to the crank shaft of the engine, while controlling said flow control valve to partly exhaust burnt gases at the end of the additional work stroke; and opening ( 180 ) at least one of the exhaust valves and permitting partly burnt gases to expel from the cylinder via said at least one exhaust valve by performing an exhaust stroke (ES).

First claim

The invention claimed is:

1. A method for operating an internal combustion engine such as an internal combustion engine of a vehicle, the engine comprising an engine cylinder at least partly defining a combustion chamber and a reciprocating piston operable between a bottom dead center and a top dead center, a number of inlet valves in fluid communication with the combustion chamber and configured to regulate the supply of an incoming fluid medium to the combustion chamber and a number of exhaust valves in fluid communication with the combustion chamber and configured to regulate the evacuation of exhaust gases from the combustion chamber, wherein any one of the inlet valves and the outlet valves comprises at least one flow control valve adapted to regulate the flow of a fluid medium passing through the flow control valve, characterized by the method comprising the following steps:
opening at least one of the inlet valves and introducing the incoming fluid medium into the cylinder of the engine by performing an intake stroke;
compressing the trapped incoming fluid medium in a first compression stroke of the cylinder, while having the number of the inlet valves and the number of the exhaust valves in a closed state;
injecting a quantity of fuel into the cylinder and combusting said injected fuel, resulting in burnt gases and remaining fuel medium;
performing a first work stroke to produce power to a crank shaft of the engine, while controlling said flow control valve to partially exhaust the burnt gases at the end of the work stroke, thereby reducing the pressure in the cylinder, resulting in an exhausted first portion of the burnt gases and a remaining second portion of the burnt gases;
compressing the remaining fluid medium in an additional compression stroke of the cylinder, while having the number of the inlet valves and the number of the exhaust valves in a closed state;
injecting an additional quantity of fuel into the cylinder, resulting in a mixture of the additional quantity of fuel, the remaining fluid medium, and the remaining second portion of the burnt gases;
combusting the mixture of the additional quantity of fuel, the remaining fluid medium, and the remaining second portion of the burnt gases;
performing an additional work stroke to produce power to the crank shaft of the engine, while controlling said flow control valve to partially exhaust burnt gases due to combustion of the mixture at the end of the additional work stroke, thereby reducing the pressure in the cylinder;
repeating the steps of additionally compressing remaining fluid medium in an additional compression stroke of the cylinder, while having the number of the inlet valves and the number of the exhaust valves in a closed state, additionally injecting an additional quantity of fuel into the cylinder, and additionally performing an additional work stroke to produce power to the crank shaft of the engine, while controlling the flow control valve to partly exhaust burnt gases at the end of the additional work stroke, thereby reducing the pressure in the cylinder, until the quantity of the remaining fluid medium in the cylinder is below a threshold value; and
opening at least one of the exhaust valves and permitting partly burnt gases to expel from the cylinder via said at least one exhaust valve by performing an exhaust stroke.

2. Method according to claim 1 , characterized by the step of partly exhausting burnt gases at the end of the work stroke being performed close to or at the bottom dead center.

3. Method according to claim 1 , characterized by using said burnt gases in said step to propel a turbo charger.

4. Method according to claim 1 , characterized by the step of partly exhausting burnt gases at the end of the work stroke being performed by controlling a valve parameter relating to any one of valve opening size, valve opening timing, valve opening duration, flow area, flow time, valve lift or a combination thereof.

5. Method according to claim 1 , characterized by the step of partly exhausting burnt gases at the end of the work stroke being performed by utilizing only one flow control valve of the group of the exhaust valves and the group of intake valves.

6. Method according to claim 1 , characterized by each one of the valves of the group of exhaust valves being a flow control valve, said step of partly exhausting burnt gases at the end of the work stroke being performed by utilizing each one of the flow control valves in the group of the exhaust valves.

7. Method according to claim 1 , characterized by the flow control valve being any one of an electro-magnetic flow control valve, a pneumatic flow control valve, an electro-pneumatic flow control valve, a hydraulic flow control valve, an electro-hydraulic flow control valve or the like.

8. Method according to claim 1 , characterized by the step of partly exhausting burnt gases at the end of the work stroke being performed by controlling an actuator operatively connected to a valve member of said flow control valve, said valve member being adapted to regulate a valve opening upon a signal from said actuator.

9. Method according to claim 8 , characterized by said valve member being any one of a rotational valve member and a lift valve member.

10. Method according to claim 1 , characterized by said intake stroke comprising the step of displacing said piston from the top dead center of the cylinder to the bottom dead center of the cylinder, while maintaining at least one inlet valve open during at least a part of the time the piston being displaced from the top dead center to the bottom dead center.

11. Method according to claim 1 , characterized by said step of compressing the trapped incoming fluid medium in said first compression stroke of the cylinder being performed by displacing said piston from bottom dead center of the cylinder to top dead center of the cylinder.

12. An internal combustion engine comprising a control unit for controlling said internal combustion engine, characterized in that the control unit is configured to perform the steps of the method according to claim 1 .

13. A vehicle comprising an internal combustion engine and a control unit according to claim 12 .

14. A computer program comprising program code means for performing the steps of claim 1 when said program is run on a computer.

Assignees

• Volvo Truck Corp

Inventors

• Lassesson Bengt
• Rahm Fredrik

Classifications

• F02B75/021 Primary

  having six or more strokes per cycle · CPC title

• F02B2075/028

  five · CPC title