BR-102025011332-A2 - CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

Abstract

The present invention relates to a control apparatus (100) for a spark-ignition type internal combustion engine (1) to which fuel alcohol containing alcohol is supplied, which includes: a sensor (3a) configured to detect an alcohol concentration (E) of the fuel alcohol supplied to the engine (1); and an ignition timing control unit (12) configured to control an ignition timing (θ) of the engine (1) to a reference ignition timing (θ0), the reference ignition timing (θ0) being a subsequent ignition timing of a predetermined optimum ignition timing (θm) and a predetermined detonation ignition timing (θk), the predetermined detonation ignition timing (θk) being predetermined so that no detonation occurs. In a case where the alcohol concentration (E) is greater than a predetermined concentration (Ex), the ignition timing control unit (12) calculates a target delay amount (Δθ2) based on the alcohol concentration (E) and corrects the reference ignition timing (θ0) to be delayed by the target delay amount (Δθ2), when the engine (1) is operated in a predetermined region (AR).

Inventors

• Taijiro Kawamura
• Naoki Kumagai

Assignees

• HONDA MOTOR CO., LTD

Dates

Publication Date

20260310

Application Date

20250604

Priority Date

20240619

Claims (2)

1. 1. Control apparatus (100) for a spark-ignition type internal combustion engine (1) supplied with alcohol-containing fuel, characterized in that it comprises: a sensor (3a) configured to detect an alcohol concentration (E) of the alcohol fuel supplied to the engine (1); an ignition timing control unit (12) configured to control an ignition timing (θ) of the engine (1) to a reference ignition timing (θ0), the reference ignition timing (θ0) being a later ignition timing of a predetermined optimum ignition timing (θm) and a predetermined detonation ignition timing (θk), the predetermined detonation ignition timing (θk) being predetermined so that detonation does not occur, wherein in a case where the alcohol concentration (E) is greater than a predetermined concentration (Ex), the ignition timing control unit (12) calculates a target delay amount (Δθ2) based on the alcohol concentration (E), and corrects the reference ignition timing (θ0) to be delayed by the target delay amount (Δθ2), when the engine (1) is operated in a predetermined region (AR), wherein the predetermined region (AR) is an operating region on a higher load side of the that an optimal operating line where a net fuel consumption rate of the engine (1) becomes higher or an operating region where the engine output (1) becomes higher.
2. 2. Apparatus (100), according to claim 1, characterized in that the target delay amount (Δθ2) is a difference between the reference ignition time (θ0) and a predetermined limit ignition time (θe) according to the alcohol concentration (E), wherein the ignition time control unit (12) corrects the reference ignition time (θ0) to be delayed by the target delay amount (Δθ2) on the condition that the limit ignition time (θe) is delayed more than the reference ignition time (θ0).

Description

BACKGROUND OF THE INVENTION Field of Invention [001] The present invention relates to a control apparatus for an internal combustion engine. Description of the Related Technique [002] In recent years, research and development has been carried out to improve fuel efficiency, contributing to energy efficiency, in order to allow more people to have easy and reliable access to sustainable and advanced energy. As a technique related to this type of device, a device that improves fuel efficiency and, at the same time, suppresses detonation is conventionally known. For example, in the device described in JP2018-013052 A, fuel consumption is reduced by advancing the ignition point more than an optimum point within a range where detonation does not occur. Furthermore, the amount of advance is increased as the alcohol concentration in the fuel increases. [003] However, in the apparatus described in document JP2018-013052 A, even if the amount of advance is simply increased, as the concentration of alcohol in the fuel increases, it is difficult to suppress combustion noise, such as abnormal sounds due to vibrations of the crankshaft and piston and combustion sounds when the cylinder pressure level is high. SUMMARY OF THE INVENTION [004] One aspect of the present invention is a control apparatus for a spark-ignition type internal combustion engine to which alcohol-containing fuel is supplied, including: a sensor configured to detect an alcohol concentration of the fuel supplied to the engine; and an ignition timing control unit configured to control an engine ignition timing to a reference ignition timing, the reference ignition timing being a later ignition timing between a predetermined optimum ignition timing and a predetermined detonation ignition timing, the predetermined detonation ignition timing being predetermined so that detonation does not occur. In a case where the alcohol concentration is greater than a predetermined concentration, the ignition timing control unit calculates a target retard amount based on the alcohol concentration and corrects the reference ignition timing to be retarded by the target retard amount when the engine is operated in a predetermined region. BRIEF DESCRIPTION OF THE DRAWINGS [005] The objects, features and advantages of the present invention will become clearer from the following embodiments in relation to the accompanying drawings, in which: [006] Figure 1 is a block diagram that schematically illustrates an example of a general configuration of a control apparatus for an internal combustion engine according to an embodiment of the present invention; [007] Figure 2 is a diagram to describe an operating region of the motor shown in Figure 1; [008] Figure 3 is a diagram to describe the cylinder pressure during high load operation of the engine shown in Figure 1; [009] Figure 4 is a diagram to describe a cylinder depression level corresponding to Figure 3; [0010] Figure 5 is a block diagram that schematically illustrates an example configuration of the main components of the device shown in Figure 1; [0011] Figure 6 is a diagram to describe the ignition timing defined by an ignition timing control unit shown in Figure 5; [0012] Figure 7 is a diagram to describe the ignition timing settings by the ignition timing control unit shown in Figure 5; [0013] Figure 8 is a diagram to describe a second retarding quantity shown in Figure 7 defined without considering an alcohol concentration in the fuel; [0014] Figure 9 is a diagram to describe the second amount of retardation shown in Figure 7 defined in consideration of the alcohol concentration of the fuel; [0015] Figure 10 is a diagram to describe a case in which the second delay quantity shown in Figure 7 is defined as “0”; [0016] Figure 11 is a diagram relating to fuel alcohol and is similar to Figure 3; and [0017] Figure 12 is a flowchart that illustrates an example of processing performed by an ECU shown in Figure 5. DETAILED DESCRIPTION OF THE INVENTION [0018] The following will describe embodiments of the present invention with reference to Figures 1 to 12. The control apparatus for the internal combustion engine according to one embodiment of the present invention is applicable to a vehicle equipped with a spark-ignition type internal combustion engine to which fuel containing alcohol (ethanol) is supplied. [0019] Figure 1 is a block diagram that schematically illustrates an example of a general configuration of a control apparatus (hereinafter, the apparatus) 100 for an internal combustion engine, according to an embodiment of the present invention. As illustrated in Figure 1, the apparatus 100 mainly includes: an engine 1, which is a spark-ignition type internal combustion engine, mounted in a vehicle not shown; a fuel tank 2, in which the fuel to be supplied to the engine 1 is stored; and an electronic control unit (ECU) 10, which controls the engine 1. [0020] Engine 1 is equipped with an intake air quantity sensor 1a to detec