Control devices for internal combustion engines

Abstract

An apparatus for controlling an internal combustion engine that can estimate a quantity of heat generated is provided. An arithmetic processing unit 20 can calculate PVκ variable according to a crank angle θ and dPVκ / dθ as a rate of change in PVκ. For convenience' sake, a “crank angle at which dPVκ / dθ is a maximum while PVκ is increasing” is to mean a “crank angle at a combustion proportion of 50%” and be referred to also as “θCA50”. PVκ calculated for θCA50 is to be referred to also as “PVκCA50”. In addition, for convenience' sake, a difference between PVκ (which is zero in the embodiment as shown in FIGS. 3 and 4) and PVκCA50 at a start of combustion is also referred to as ΔPVκCA50. A total quantity of heat generated Q is assumed to be twice as much as a value of ΔPVκCA50.

Description

technical field [0001] The invention relates to a control device for an internal combustion engine. Background technique [0002] Conventionally, for example, as disclosed in Japanese Patent Application Laid-Open No. 2006-144643, there is known a technique for obtaining various information on the calorific value during combustion of an internal combustion engine by calculation. The aforementioned gazette specifically discloses a technique of calculating a calorific value immediately after combustion using an output value of a cylinder internal pressure sensor, and calculating a combustion air-fuel ratio based on the calorific value. [0003] prior art literature [0004] patent documents [0005] Patent Document 1: Japanese Patent Document Laid-Open No. 2006-144643; [0006] Patent Document 2: Japanese Patent Document Laid-Open No. 2007-120392; [0007] Patent Document 3: Japanese Patent Application Laid-Open No. 2007-113396. [0008] There is known a technique for obta...

AI Technical Summary

Problems solved by technology

[0010] However, in the method that always requires the detection value of the sensor at the end of combustion, no final conclusion on the amount of heat generation can be drawn until the end of combustion

In addition, under operating conditions where the combustion end timing lags behind the usual operating conditions, the combustion end timing may be delayed to the exhaust valve opening timing.

In such a case, there will be unique disadvantages when using the output value of the cylinder internal pressure sensor

That is, in such a case, it may be difficult to clearly determine the combustion end time based on the output value of the cylinder internal pressure sensor, and it may be inappropriate to use the output value of the cylinder internal pressure sensor on the basis of the calculation of the amount of heat generated at the combustion end time. of

Images