Internal combustion engine system

Patent metadata

Field	Value
Publication number	US-9909519-B2
Application number	US-201514750317-A
Country	US
Kind code	B2
Filing date	Jun 25, 2015
Priority date	Jun 27, 2014
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

An internal combustion engine system includes: an in-cylinder pressure sensor; a crank angle sensor; and a seal portion that seals a space between an outer face of a housing and a wall surface of a cylinder head. A slope that is a ratio of the amount of decrease in a heat release amount relative to the amount of increase in a crank angle is calculated in a period during an expansion stroke from a combustion end point until an opening timing of an exhaust valve. The existence or nonexistence of an abnormality in the sealing function of the seal portion is determined based on whether or not a ratio of the amount of decrease in the slope to the amount of increase in an engine speed is greater than a threshold value.

First claim

The invention claimed is:

1. An internal combustion engine system, comprising:
an in-cylinder pressure sensor that includes: a housing that is formed into a cylindrical shape; a pressure receiving member that is provided at one end of the housing and configured to receive an in-cylinder pressure, the in-cylinder pressure being a pressure of a gas inside a combustion chamber; and a pressure detecting element that is arranged inside the housing and into which a compressive load that is based on the in-cylinder pressure configured to be input from the pressure receiving member, the pressure detecting element being configured to emit an output in accordance with the input compressive load;
a crank angle sensor configured to detect a crank angle;
a seal portion configured to, at a position that is further on the combustion chamber side than the pressure detecting element in an axial direction of the housing, seal a space between an outer face of the housing and a wall surface of the combustion chamber that surrounds the housing; and
a controller, the controller programmed to:
calculate a heat release amount in a cylinder that is an amount of heat released by combustion, based on in-cylinder pressure data that is data regarding an in-cylinder pressure that is detected by the in-cylinder pressure sensor;
calculate a first ratio that is a ratio of an amount of decrease in a heat release amount relative to an amount of increase in a crank angle in a period during an expansion stroke from an crank angle at which a calculated heat release amount exhibits a maximum value until an opening timing of an exhaust valve; and
determine existence or nonexistence of an abnormality in a sealing function of the seal portion based on the first ratio and an engine speed,
wherein, when a second ratio that is a ratio of an amount of decrease in the first ratio relative to an amount of increase in an engine speed is greater than a first threshold value, the controller determines that the sealing function of the seal portion is abnormal,
wherein the controller calculates a mass fraction burned and calculates an ignition delay period using a spark timing and a calculated mass fraction burned,
wherein the controller corrects a calculated ignition delay period in accordance with a size of the second ratio, and
wherein the controller adjusts at least one of a fuel injection amount, an intake air amount and an ignition energy to eliminate a difference between a calculated ignition delay period and a target value of the ignition delay period.

2. The internal combustion engine system according to claim 1 , wherein the controller makes a determination with respect to an abnormality in the sealing function of the seal portion at a time that an internal combustion engine is operating under a stoichiometric air-fuel ratio.

3. An internal combustion engine system, comprising:
an in-cylinder pressure sensor that includes: a housing that is formed into a cylindrical shape; a pressure receiving member that is provided at one end of the housing and configured to receive an in-cylinder pressure, the in-cylinder pressure being a pressure of a gas inside a combustion chamber; and a pressure detecting element that is arranged inside the housing and into which a compressive load that is based on the in-cylinder pressure configured to be input from the pressure receiving member, the pressure detecting element being configured to emit an output in accordance with the input compressive load;
a crank angle sensor configured to detect a crank angle;
a seal portion configured to, at a position that is further on the combustion chamber side than the pressure detecting element in an axial direction of the housing, seal a space between an outer face of the housing and a wall surface of the combustion chamber that surrounds the housing; and
a controller, the controller programmed to:
calculate a heat release amount in a cylinder that is an amount of heat released by combustion, based on in-cylinder pressure data that is data regarding an in-cylinder pressure that is detected by the in-cylinder pressure sensor;
calculate a first ratio that is a ratio of an amount of decrease in a heat release amount relative to an amount of increase in a crank angle in a period during an expansion stroke from an crank angle at which a calculated heat release amount exhibits a maximum value until an opening timing of an exhaust valve; and
determine existence or nonexistence of an abnormality in a sealing function of the seal portion based on the first ratio and an engine speed,
wherein, when a second ratio that is a ratio of an amount of decrease in the first ratio relative to an amount of increase in an engine speed is greater than a first threshold value, the controller determines that the sealing function of the seal portion is abnormal,
wherein the controller calculates a mass fraction burned and calculates a combustion center based on a calculated mass fraction burned,
wherein the controller corrects a calculated combustion center in accordance with a size of the second ratio, and
wherein the controller adjusts a spark timing to eliminate a difference between a calculated combustion center and a target combustion center.

4. An internal combustion engine system, comprising:
an in-cylinder pressure sensor that includes: a housing that is formed into a cylindrical shape; a pressure receiving member that is provided at one end of the housing and configured to receive an in-cylinder pressure, the in-cylinder pressure being a pressure of a gas inside a combustion chamber; and a pressure detecting element that is arranged inside the housing and into which a compressive load that is based on the in-cylinder pressure configured to be input from the pressure receiving member, the pressure detecting element being configured to emit an output in accordance with the input compressive load;
a crank angle sensor configured to detect a crank angle;
a seal portion configured to, at a position that is further on the combustion chamber side than the pressure detecting element in an axial direction of the housing, seal a space between an outer face of the housing and a wall surface of the combustion chamber that surrounds the housing; and
a controller, the controller programmed to:
calculate a heat release amount in a cylinder that is an amount of heat released by combustion, based on in-cylinder pressure data that is data regarding an in-cylinder pressure that is detected by the in-cylinder pressure sensor;
calculate a first ratio that is a ratio of an amount of decrease in a heat release amount relative to an amount of increase in a crank angle in a period during an expansion stroke from an crank angle at which a calculated heat release amount exhibits a maximum value until an opening timing of an exhaust valve; and
determine existence or nonexistence of an abnormality in a sealing function of the seal portion based on the first ratio and an engine speed,
wherein when the first ratio is greater than a second threshold value that corresponds to an engine speed in a cycle in which in-cylinder pressure data that serves as a basis for calculation of the first ratio is acquired, the controller determines that the sealing function of the seal portion is abnormal,
wherein the second threshold value is set so as to become smaller when the engine speed is high in comparison to when the engine speed is low,
wherein the controller calculates a mass fraction burned and calculates an ignition delay period using a spark timing and a calculated mass fraction burned,
wherein the controller corrects a calculated ignition delay period in accordance with a size of the first ratio, and
wherein the controller adjusts at least one of a fuel injection amount, an intake air amount and an ignition energy to eliminate a di

Assignees

• Toyota Motor Co Ltd

Inventors

• Yasuda Hiromichi

Classifications

• F02D2041/228

  Warning displays · CPC title

• F02P5/153

  dependent on combustion pressure · CPC title

• F02B77/088

  relating to tightness · CPC title

• F02D2200/101

  Engine speed · CPC title

• F02P5/151

  with means for compensating the variation of the characteristics of the engine or of a sensor, e.g. by ageing · CPC title