Abstract: Based on respective signals from the combustion pressure sensor and a crank angle sensor, heat generation amount data in which a heat generation amount and a crank angle are related to each other is generated, and an estimated heat generation amount is calculated based on a fuel amount in the combustion cycle. When a final value of a heat generation amount in the combustion cycle is smaller than the estimated heat generation amount, the combustion state parameter is calculated based on the heat generation amount data to a crank angle corresponding to the final value of the heat generation amount. When the final value of the heat generation amount is equal to or larger than the estimated heat generation amount, the combustion state parameter is calculated based on the heat generation amount data to a crank angle at which the heat generation amount reaches the estimated heat generation amount.

Abstract: A cooling device for an internal combustion engine includes a pump portion, a circulation water passage, a thermostat configured to switch between a state where the coolant is circulated to a heat exchange water passage on which a radiator is disposed and a state where the coolant is not circulated to the heat exchange water passage, and a control unit configured to control the pump portion. The control unit is configured to control a three-way valve such that a first pump and a second pump are connected in parallel when the thermostat switches to the state where the coolant is circulated to the heat exchange water passage and controls the three-way valve such that the first pump and the second pump are connected in series when the thermostat switches to the state where the coolant is not circulated to the heat exchange water passage.

Abstract: A cooling device for an internal combustion engine includes a pump portion, a circulation water passage, a thermostat configured to switch between a state where the coolant is circulated to a heat exchange water passage on which a radiator is disposed and a state where the coolant is not circulated to the heat exchange water passage, and a control unit configured to control the pump portion. The control unit is configured to control a three-way valve such that a first pump and a second pump are connected in parallel when the thermostat switches to the state where the coolant is circulated to the heat exchange water passage and controls the three-way valve such that the first pump and the second pump are connected in series when the thermostat switches to the state where the coolant is not circulated to the heat exchange water passage.

Abstract: A rough road determination device (100) is mounted on a vehicle (1) that is equipped with an internal combustion engine (10) having a crank angle sensor (31). This rough road determination device is equipped with determination means (20) for determining whether or not a road on which the vehicle travels is a rough road, by comparing a first amplitude fluctuation amount as an amplitude fluctuation amount of one pulse of an output of the crank angle sensor, which is determined in advance on the basis of a rotational speed of the internal combustion engine, with a second amplitude fluctuation amount as an amplitude fluctuation amount of one pulse that is actually output from the crank angle sensor.

Abstract: Based on respective signals from the combustion pressure sensor and a crank angle sensor, heat generation amount data in which a heat generation amount and a crank angle are related to each other is generated, and an estimated heat generation amount is calculated based on a fuel amount in the combustion cycle. When a final value of a heat generation amount in the combustion cycle is smaller than the estimated heat generation amount, the combustion state parameter is calculated based on the heat generation amount data to a crank angle corresponding to the final value of the heat generation amount. When the final value of the heat generation amount is equal to or larger than the estimated heat generation amount, the combustion state parameter is calculated based on the heat generation amount data to a crank angle at which the heat generation amount reaches the estimated heat generation amount.

Abstract: A rough road determination device (100) is mounted on a vehicle (1) that is equipped with an internal combustion engine (10) having a crank angle sensor (31). This rough road determination device is equipped with determination means (20) for determining whether or not a road on which the vehicle travels is a rough road, by comparing a first amplitude fluctuation amount as an amplitude fluctuation amount of one pulse of an output of the crank angle sensor, which is determined in advance on the basis of a rotational speed of the internal combustion engine, with a second amplitude fluctuation amount as an amplitude fluctuation amount of one pulse that is actually output from the crank angle sensor.

Abstract: An internal combustion engine control device includes: detection means (216, 110) for detecting crank angle speed of the internal combustion engine (200); calculation means (120) for calculating a combustion state index value (MI) for indicating a combustion state of the internal combustion engine based on the crank angle speed detected by the detection means; and first determination means (130) for determining whether or not white smoke is generated from the internal combustion engine and whether or not misfire of the internal combustion engine occurs by comparing the combustion state index value calculated by the calculation means with a specified first threshold (A) and a specified second threshold (B) larger than the first threshold.