Compression ignition engine with supercharger

Patent metadata

Field	Value
Publication number	US-11111865-B2
Application number	US-201916675508-A
Country	US
Kind code	B2
Filing date	Nov 6, 2019
Priority date	Dec 26, 2018
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

A compression ignition engine with a supercharger is provided, which includes one or more valves configured to switch a state between a first state where intake air is boosted by the supercharger and a second state where it is not boosted, a fluid temperature adjuster configured to adjust a temperature of engine coolant to be supplied to a radiator from an engine body, and a controller. When the engine operates in a high-load range, the controller controls the combustion mode to be in a compression ignition combustion mode, and causes the valve(s) to be in the first state, and in a low-load range, the controller causes the valve(s) to be in the second state. In the high-load range, the controller outputs a control signal to the fluid temperature adjuster so that a target temperature of the engine coolant is lowered than that in the low-load range.

First claim

What is claimed is:

1. A compression ignition engine with a supercharger, comprising:
an engine body having a cylinder where a combustion chamber is formed;
the supercharger, configured to boost intake air to the combustion chamber of the engine body;
one or more valves configured to switch a state between a first state in which the intake air is boosted by the supercharger and a second state in which the intake air is not boosted by the supercharger;
a fluid temperature adjuster comprising a grille shutter provided in front of a radiator and configured to adjust a temperature of engine coolant configured to be supplied to the radiator from the engine body to cool the engine body, the grille shutter comprising a plurality of flappers which rotate on respective axes extending in a vehicle width direction; and
a controller comprised of circuitry, configured to control operation of the engine body including operations of the one or more valves and the fluid temperature adjuster,
wherein when the controller determines that an operating state of the engine body is in a high-load operating range where an engine load is more than a given load, the controller controls a combustion mode of the engine body to be in a compression ignition combustion mode in which an unburnt mixture gas is self-ignited during flame propagation combustion of a mixture gas caused by jump-spark ignition inside the combustion chamber,
wherein when the controller determines that the operating state of the engine body is in the high-load operating range, causing the one or more valves to be in the first state, while when the operating state of the engine body is in a low-load operating range in which the load is lower than the given load, causing the one or more valves to be in the second state,
wherein when the controller determines that the operating state of the engine body is in the high-load operating range, the controller outputs a control signal to the grille shutter so that an opening of the grille shutter becomes larger, compared with the opening of the grille shutter when the operating state of the engine body is in the low-load operating range,
wherein the fluid temperature adjuster comprises the grille shutter and a radiator fan configured to adjust an amount of air passing through the radiator, the radiator fan provided rearward of the radiator,
wherein when the operating state of the engine body is in the high-load operating range, the controller increases a rotational speed of the radiator fan, compared with the rotational speed of the radiator fan when the operating state of the engine body is in the low-load operating range, and
wherein the controller controls the grille shutter and the radiator fan such that:
a detection result of a fluid temperature sensor becomes a first fluid temperature when the operating state of the engine body is in a low-speed operating range and in the low-load operating range, and
the opening of the grille shutter is fully closed and the rotational speed of the radiator fan is set to zero when the detection result of the fluid temperature sensor is below the first fluid temperature.

2. The compression ignition engine of claim 1 ,
wherein the supercharger is a mechanical supercharger disposed in an intake passage connected to the engine body.

3. The compression ignition engine of claim 2 ,
wherein the intake passage is provided with a bypass passage bypassing the mechanical supercharger, and
wherein the compression ignition engine further includes a clutch configured to intercept and permit transmission of a driving force to the mechanical supercharger, and the one or more valves include an air bypass valve configured to open and close the bypass passage.

4. The compression ignition engine of claim 1 ,
wherein the supercharger is a turbocharger having a turbine disposed in an exhaust passage connected to the engine body, and a compressor disposed in an intake passage connected to the engine body and configured to be driven by the turbine.

5. The compression ignition engine of claim 4 ,
wherein the exhaust passage is provided with a turbine bypass passage bypassing the turbine, and the intake passage is provided with a compressor bypass passage bypassing the compressor, and
wherein the one or more valves include a waste gate valve configured to open and close the turbine bypass passage, and a compressor bypass valve configured to open and close the compressor bypass passage.

6. The compression ignition engine of claim 1 ,
wherein the controller controls the grille shutter such that an angle at an acute angle side of the flappers with respect to a vertical direction of the grille shutter is adjusted to be in a range below 30° to thereby maintain the temperature of the engine coolant above the first fluid temperature, when the operating state of the engine body is in the low-speed operating range and in the low-load operating range.

7. The compression ignition engine of claim 1 ,
wherein the controller controls the grille shutter and the radiator fan such that the grille shutter is opened and the radiator fan is started when the operating state of the engine body is in a high-speed operating range and in the low-load operating range, even when the detection result of the fluid temperature sensor is below the first fluid temperature, and the opening of the grille shutter and the rotational speed of the radiator fan are controlled so that the detection result of the fluid temperature sensor is below the first fluid temperature and above a second fluid temperature.

8. The compression ignition engine of claim 7 ,
wherein the controller controls the grille shutter such that an angle at an acute angle side of the flappers with respect to a vertical direction of the grille shutter is adjusted to be in a range above 30° and below 60° when the operating state of the engine body is in the high-speed operating range and in the low-load operating range.

9. The compression ignition engine of claim 1 ,
wherein the controller controls the grille shutter and the radiator fan such that the grille shutter is opened and the radiator fan is started when the operating state of the engine body is in the high-load operating range, even when the detection result of the fluid temperature sensor is below the first fluid temperature, and the opening of the grille shutter and the rotational speed of the radiator fan are controlled so that the detection result of the fluid temperature sensor becomes a second fluid temperature.

10. The compression ignition engine of claim 9 ,
wherein the controller controls the grille shutter such that an angle at an acute angle side of the flappers with respect to a vertical direction of the grille shutter is adjusted to be in a range above 60° and below 90° when the operating state of the engine body is in the high-load operating range.

Assignees

• Mazda Motor

Inventors

• Hikitani Shinichi
• Umehara Hajime
• Nagano Naoki
• Kusunoki Tomokuni
• Takahata Tatsuya
• Watanabe Shinji
• Koutoku Masanobu
• Ueno Toshinori
• Murakami Katsuya
• Yokoyama Nobuhiko

Classifications

• F01P7/164

  by varying pump speed · CPC title

• F02B1/12

  with compression ignition (with fuel-air charge ignited by compression ignition of an additional fuel F02B7/00) · CPC title

• F01P7/048

  using electrical drives · CPC title

• F02M31/042

  Combustion air · CPC title

• F01P7/10

  by throttling amount of air flowing through liquid-to-air heat exchangers · CPC title