Stroke determination method of four cycle internal combustion engine and device thereof

A stroke determination method of a four cycle internal combustion engine, in which a section where a crank shaft of a four cycle internal combustion engine makes one rotation from a position corresponding to a top dead point of a piston of a specified cylinder is taken as a determination object section and each determination object section is determined whether said determination object section is a section where an intake stroke and a compression stroke are performed at said specified cylinder or a section where a combustion stroke and an exhaust stroke are performed, comprising the steps of:

• providing sample timing signal generating means for generating a sample timing signal plural times in each determination object section and a reference signal generator for generating a reference signal at the reference rotational angle position set at a specified rotational angle position of the crank shaft of said internal combustion engine;
• sampling an intake air pressure, in which a change in a stroke to be performed by said specified cylinder is reflected every time when said sample timing signal is generated, of said internal combustion engine;
• detecting each determination object section based on said reference signal;
• finding a difference between an intake air pressure sampled one time before and an intake air pressure sampled this time as a determination object variable every time when said intake air pressure is sampled so that a maximum value in each determination object section of the determination object variable at the time when an inclination of the intake air pressure is negative is found as a determination object value;
• and
• determining each determination object section to be the section where the intake stroke and the compression stroke are performed at said specified cylinder, when said determination object value found in each determination object section is larger than the determination object value found in the determination object section which is one section before each determination object section.

A stroke determination method of a four cycle internal combustion engine, in which a section where a crank shaft of the four cycle internal combustion engine makes one rotation from a position corresponding to a top dead point of a piston of a specified cylinder is taken as a determination object section and each determination object section is determined whether said determination object section is a section where an intake stroke and a compression stroke are performed at said specified cylinder or a section where a combustion stroke and an exhaust stroke are performed, comprising the steps of:

• providing sample timing signal generating means for generating a sample timing signal plural times in each determination object section and a reference signal generator for generating a reference signal at the reference rotational angle position set at a specified rotational angle position of the crank shaft of said internal combustion engine;
• sampling an intake air pressure, in which a change in a stroke to be performed by said specified cylinder is reflected, of said internal combustion engine every time when said sample timing signal is generated;
• detecting each determination object section based on said reference signal;
• finding a difference between an intake air pressure sampled one time before and an intake air pressure sampled this time as a determination object variable every time said intake air pressure is sampled and, at the same time, finding a cumulative value of the determination object variable found in each determination object section as the determination object value;
• and
• determining each determination object section to be the section where the intake stroke and the compression stroke are performed at said specified cylinder when said determination object value found in each determination object section is larger than the determination object value found in the determination object section which is one section before each determination object section.

A stroke determination method of a four cycle internal combustion engine, in which a section where a crank shaft of the four cycle internal combustion engine makes one rotation from a position corresponding to the top dead point of a piston of a specified cylinder is taken as a determination object section and each determination object section is determined whether said determination object section is a section where an intake stroke and a compression stroke are performed at said specified cylinder or a section where a combustion stroke and an exhaust stroke are performed, comprising the steps of:

• providing sample timing signal generating means for generating a sample timing signal plural times in each determination object section and a reference signal generator for generating a reference signal at the reference rotational angle position set at a specified rotational angle position of the crank shaft of said internal combustion engine;
• sampling an intake air pressure, in which a change in a stroke to be performed by said specified cylinder is reflected, of said internal combustion engine every time when said sample timing signal is generated;
• detecting each determination object section based on said reference signal;
• finding a difference between an intake air pressure sampled one time before and an intake air pressure sampled this time as a determination object variable every time said intake air pressure is sampled and, at the same time, finding an average value of the determination object variable found in each determination object section as the determination object value;
• and
• determining each determination object section to be the section where the intake stroke and the compression stroke are performed at the specified cylinder, when said determination object value found in each determination object section is larger than the determination object value found in the determination object section which is one section before each determination object section.

A stroke determination device of a four cycle internal combustion engine, in which a section where a crank shaft of the four cycle internal combustion engine makes one rotation from a position corresponding to the top dead point of a piston of a specified cylinder is taken as a determination object section and each determination object section is determined whether said determination object section is a section where an intake stroke and a compression stroke are performed at said specified cylinder or a section where a combustion stroke and an exhaust stroke are performed, comprising:

• sample timing signal generating means for generating a sample timing signal plural times in each determination object section;
• a reference signal generator for generating a reference signal at the reference rotational angle position set at a specified rotational angle position of the crank shaft of said internal combustion engine;
• determination object section detection means for detecting each determination object section based on the generating position of said reference signal;
• intake air pressure sampling means for sampling the intake air pressure, in which the change in the stroke to be performed by said specified cylinder is reflected, of said internal combustion engine every time when the sample timing signal is generated;
• determination object variable maximum value arithmetical operation means for finding the absolute value of the difference between the intake air pressure sampled one time before and the intake air pressure sampled this time as the determination object variable every time when the intake air pressure is sampled and, at the same time, finding the maximum value in each determination object section of said determination object variable at the time when the inclination of the change in said intake air pressure is negative as the determination object value;
• and
• determination means for determining each determination object section to be the section where the intake stroke and the compression stroke are performed at said specified cylinder when the determination object value in each determination object section found by said determination object variable maximum value arithmetical operation means is larger than the determination object value found in the determination object section which is one section before each determination object section.

A stroke determination device of a four cycle internal combustion engine, in which a section where a crank shaft of the four cycle internal combustion engine makes one rotation from a position corresponding to the top dead point of a piston of a specified cylinder is taken as a determination object section and each determination object section is determined whether said determination object section is a section where an intake stroke and a compression stroke are performed at said specified cylinder or a section where a combustion stroke and an exhaust stroke are performed, comprising:

• sample timing signal generating means for generating a sample timing signal plural times in each determination object section;
• a reference signal generator for generating a reference signal at the reference rotational angle position set at a specified rotational angle position of the crank shaft of said internal combustion engine;
• determination object section detection means for detecting each determination object section based on the generating position of said reference signal;
• intake air pressure sampling means for sampling the intake air pressure, in which the change in the stroke to be performed by said specified cylinder is reflected, of said internal combustion engine every time when the sample timing signal is generated;
• determination object variable cumulative value arithmetical operation means for finding the difference between the intake air pressure sampled one time before and the intake air pressure sampled this time as the determination object variable every time when the intake air pressure is sampled and, at the same time, finding the cumulative value of the determination object variable found in each determination object section as the determination object value;
• and
• determination means for determining each determination object section to be the section where the intake stroke and the compression stroke are performed at the specified cylinder when said determination object value found in each determination object section is larger than the determination object value found in the determination object section which is one section before each determination object section.

A stroke determination device of a four cycle internal combustion engine, in which a section where a crank shaft of the four cycle internal combustion engine makes one rotation from a position corresponding to the top dead point of a piston of a specified cylinder is taken as a determination object section and each determination object section is determined whether said determination object section is a section where an intake stroke and a compression stroke are performed at said specified cylinder or a section where a combustion stroke and an exhaust stroke are performed, comprising:

• sample timing signal generating means for generating a sample timing signal plural times in each determination object section;
• a reference signal generator for generating a reference signal at the reference rotational angle position set at a specified rotational angle position of the crank shaft of said internal combustion engine;
• determination object section detection means for detecting each determination object section based on the generating position of said reference signal;
• intake air pressure sampling means for sampling the intake air pressure, in which the change in the stroke to be performed by said specified cylinder is reflected, of said internal combustion engine every time when the sample timing signal is generated;
• determination object variable average value arithmetical operation means for finding the difference between the intake air pressure sampled one time before and the intake air pressure sampled this time as the determination object variable every time when the intake air pressure is sampled and, at the same time, finding the average value of the determination object variable found in each determination object section as the determination object value;
• and
• determination means for determining each determination object section to be the section where the intake stroke and the compression stroke are performed at the specified cylinder when said determination object value found in each determination object section is larger than the determination object value found in the determination object section which is one section before each determination object section.