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EP-4279730-B1 - ENGINE CONTROL DEVICE

EP4279730B1EP 4279730 B1EP4279730 B1EP 4279730B1EP-4279730-B1

Inventors

  • INOUE, YOSHIYA
  • ASAKURA, Ryota
  • NAKADA, Ryota
  • SHIROTA, TAKAYUKI
  • IIZUKA, Sho
  • KURATA, KAZUO

Dates

Publication Date
20260506
Application Date
20210329

Claims (4)

  1. A control device (20) for controlling an engine (10), the control device (20) comprising: main-chamber injecting means (1, 3) that supplies a main chamber (8) with fuel; sub-chamber injecting means (2) that supplies a sub chamber (5) with fuel after the main chamber injecting means (1, 3) supplies the fuel; estimating means (21) that estimates a degree (N) of knocking serving as indices of an intensity of the knocking and an occurrence frequency of the knocking; fuel controlling means (22) that carries out reduction control that reduces a sub-chamber fuel amount representing an amount of fuel supplied by the sub-chamber injecting means(2); and ignition controlling means (23) that carries out ignition retarding control that retards an ignition timing, wherein when the degree (N) of the knocking is a first predetermined value (N 1 ) or more and is also less than a second predetermined value (N 2 ) larger than the first predetermined value (N 1 ), the reduction control of the sub-chamber fuel amount is carried out by the fuel controlling means (22) first, and then the ignition retarding control is carried out by the ignition controlling means (23).
  2. The control device (20) according to claim 1, wherein when the degree (N) of the knocking is the second predetermined value (N 2 ) or more, the ignition controlling means (23) carries out the ignition retarding control first, and then the fuel controlling means (22) carries out the reduction control.
  3. The control device (20) according to claim 1 or 2, wherein the ignition controlling means (23) retards the ignition timing and then gradually reduces a retarding amount.
  4. The control device (20) according to any one of claims 1 to 3, wherein when the degree (N) of the knocking is less than a third predetermined value (N 3 ) smaller than the first predetermined value (N 1 ), the fuel controlling means (22) carries out fuel control that increases the sub-chamber fuel amount.

Description

[Technical Field] The present invention relates to a control device for controlling an engine having a main chamber and a sub chamber in a combustion chamber. [Background Technique] Conventionally, a divided-combustion-chamber engine has been known in which a main chamber (main combustion chamber) and a sub chamber (sub combustion chamber) communicating with each other are formed in a combustion chamber and an ignition plug electrode is arranged inside the sub chamber. In this engine, a flame generated inside the sub chamber is formed so as to be ejected toward the main chamber in a torch-like form. This makes it possible to, even if the air-fuel ratio in the main chamber is leaner than the stoichiometric air-fuel ratio, efficiently combust the fuel-air mixture (see Patent Document 1). [Prior Art Reference] [Patent Document] [Patent Document 1] Japanese Laid-open Patent Publication No. 2018-105171 WO2014049646A1 discloses an internal combustion engine with pre-chamber fuel injection, pre-chamber spark ignition and knock control. [Summary of Invention] [Problems to be Solved by Invention] A divided-combustion-chamber engine needs to supply an adequate amount of fuel to the interior of the sub chamber and therefore the injection period during which fuel injection to the sub chamber is performed is more likely to be restricted as compared to other engines. In addition, since the correlation between an injection period and an ignition timing of fuel is important, the range of the proper ignition timing is narrower than that of other engines. For the above, a divided-combustion-chamber engine has a difficulty in significantly changing the ignition timing to deal with inconvenience such as knocking or combustion failure and in consequently stabilizing the combustion state thereof. With the foregoing problems in view, one of the objects of the present embodiment is to enhance the combustion state of a divided-chamber combustion engine. In addition to this object, influences and effects which are derived from each configuration of "an embodiment to carry out the invention" to be described below and which conventional technique does not attain can be regarded as other objects of the present disclosure. [Means to Solve the Problem] The invention is defined by the control device according to claim 1. According to the present embodiment, a control device for controlling an engine includes main-chamber injecting means that supplies a main chamber with fuel; sub-chamber injecting means that supplies a sub chamber with fuel after the main chamber injecting means supplies the fuel; estimating means that estimates a degree of knocking serving as indices of an intensity of the knocking and an occurrence frequency of the knocking; fuel controlling means that carries out, when the degree of the knocking is a first predetermined value or more, fuel control that reduces a sub-chamber fuel amount representing an amount of fuel supplied by the sub-chamber injecting means; and ignition controlling means that carries out ignition control that retards an ignition timing. When the degree of the knocking is the first predetermined value or more after the fuel control is carried out by the fuel controlling means, the ignition control is carried out. [Effect of Invention] The control device for controlling an engine of the present embodiment can enhance the combustion state of a divided-combustion-chamber engine. [Brief Description of Drawings] [FIG. 1] FIG. 1 is a diagram schematically showing the configuration of an engine adopting a control device according to an embodiment.[FIG. 2] FIG. 2 is a diagram schematically showing the configuration of another engine adopting the control device according to the embodiment.[FIG. 3] FIG. 3 is a map to set a first index value related to a degree of knocking.[FIG. 4] FIGs. 4(A) and 4(B) maps to set a second index value and a third index value related to a degree of knocking, respectively.[FIG. 5] FIG. 5 is a schematic diagram showing relationship between a degree of knocking and types of control.[FIG. 6] FIG. 6 is a flow diagram showing the details of control.[FIG. 7] FIG. 7 is a flow diagram showing the details of control.[FIG. 8] FIG. 8 is a flow diagram showing the details of control. [Embodiment to Carry out Invention] [1. Structure] FIGs. 1-8 are diagrams showing a control device for controlling an engine 10 (internal combustion engine) mounted on a vehicle. Both FIG. 1 and FIG. 2 schematically illustrate the structure of a passive-type divided-combustion-chamber engine 10 in which a main chamber 8 (main combustion chamber) and a sub chamber 5 (sub combustion chamber) communicating with each other are formed in a cylinder. FIG. 1 illustrates an example of the structure of the engine 10 that is separately provided with an injection valve (sub-chamber injection valve 2) that supplies a sub chamber 5 with fuel and an injection valve (port injection valve 1, cylinder injection valve 3) that supp