Abstract: An engine includes a cylinder pressure sensor inserted into a through-hole of a cylinder head. A sealing member that seals between a hole wall surface and a body-side wall surface. A dimension relationship of D1<D3×(D4/D2) is satisfied where: D1 is a distance in a direction of a central axis from a reference position of the sealing member to a first given position; D2 is a distance between the hole wall surface and the body-side wall surface at the first given position; D3 is a distance in the direction of the central axis from the reference position to a second given position; and D4 is a distance between the hole wall surface and the body-side wall surface at the second given position.

Abstract: An engine includes a cylinder pressure sensor inserted into a through-hole of a cylinder head. A sealing member that seals between a hole wall surface and a body-side wall surface. A dimension relationship of D1<D3×(D4/D2) is satisfied where: D1 is a distance in a direction of a central axis from a reference position of the sealing member to a first given position; D2 is a distance between the hole wall surface and the body-side wall surface at the first given position; D3 is a distance in the direction of the central axis from the reference position to a second given position; and D4 is a distance between the hole wall surface and the body-side wall surface at the second given position.

Abstract: For an A/F sensor 10 equipped with a sensor element 11, a cover 12 that covers the sensor element, and a heater 13 that raises the temperature of the sensor element 11 and provided to an exhaust system of an engine, an ECU 1A has timing estimation means for estimating a timing of vaporizing and disappearing of cover condensed water that is condensed water generated inside and outside of the cover 12 and determining whether an estimated timing has come, and heater control means for supplying a current to the heater 13 so that the temperature of the sensor element 11 becomes equal to a temperature at which the sensor element 11 does not crack even if the sensor element 11 is moistened until the estimated timing estimated by the timing estimation means at which the cover condensed water vaporizes and disappears comes.

Abstract: A present exhaust purifying apparatus comprises a SCR catalyst, a urea-water injector, and a downstream air-fuel ratio sensor (an oxygen concentration sensor having a diffusion resistance layer) disposed at a position downstream of the SCR catalyst. The present apparatus, when a predetermined condition is satisfied, stops injecting the urea-water from the urea-water injector, and obtains an output value of the downstream air-fuel ratio sensor, as a first output value, in that state. The present apparatus obtains an output value of the downstream air-fuel ratio sensor when the urea-water is being injected from the urea-water injector, as a second output value. The present apparatus obtains a concentration of ammonia which flows out from the SCR catalyst based on the difference between the first output value and the second output value.

Abstract: A gas sensor is fitted to an exhaust pipe such that an end face in which a vent-hole is formed is not visible from any position of inlet portions of the exhaust pipe. Thus, it is possible to suppress entry of condensed water through the vent hole formed in the end face of the gas sensor. As a result, it is possible to minimize occurrence of a crack in the gas sensor.

Abstract: For an A/F sensor 10 equipped with a sensor element 11, a cover 12 that covers the sensor element, and a heater 13 that raises the temperature of the sensor element 11 and provided to an exhaust system of an engine, an ECU 1A has timing estimation means for estimating a timing of vaporizing and disappearing of cover condensed water that is condensed water generated inside and outside of the cover 12 and determining whether an estimated timing has come, and heater control means for supplying a current to the heater 13 so that the temperature of the sensor element 11 becomes equal to a temperature at which the sensor element 11 does not crack even if the sensor element 11 is moistened until the estimated timing estimated by the timing estimation means at which the cover condensed water vaporizes and disappears comes.

Abstract: A present exhaust purifying apparatus comprises a SCR catalyst, a urea-water injector, and a downstream air-fuel ratio sensor (an oxygen concentration sensor having a diffusion resistance layer) disposed at a position downstream of the SCR catalyst. The present apparatus, when a predetermined condition is satisfied, stops injecting the urea-water from the urea-water injector, and obtains an output value of the downstream air-fuel ratio sensor, as a first output value, in that state. The present apparatus obtains an output value of the downstream air-fuel ratio sensor when the urea-water is being injected from the urea-water injector, as a second output value. The present apparatus obtains a concentration of ammonia which flows out from the SCR catalyst based on the difference between the first output value and the second output value.

Abstract: A gas sensor is fitted to an exhaust pipe such that an end face in which a vent-hole is formed is not visible from any position of inlet portions of the exhaust pipe. Thus, it is possible to suppress entry of condensed water through the vent hole formed in the end face of the gas sensor. As a result, it is possible to minimize occurrence of a crack in the gas sensor.

Abstract: A gas sensor mounting structure (10) is provided for mounting a gas sensor (1) that has a gas sensor element (2) and a sensor cover (3) covering the gas sensor element (2), in an exhaust manifold (5). The gas sensor (1) is mounted in the exhaust manifold (5) at such an angle with respect to the gas flow direction in the exhaust manifold (5) that makes it difficult for water present in the exhaust manifold (5) to come in contact with the gas sensor element (2). Also, the gas sensor (1) is mounted in the exhaust manifold (5) such that an axis (P) of the gas sensor (1) is not generally perpendicular to the exhaust manifold (5) at the mounting position. In addition, the gas sensor (1) is mounted immediately after a bend (R) in the exhaust manifold (5).

Abstract: An internal combustion engine (1) generates power by burning a mixture of fuel and air in each combustion chamber (3). The internal combustion engine (1) is provided with an in-cylinder pressure sensor (15) disposed in the combustion chamber (3) and an ECU (20). The ECU (20) calculates control parameters each of which is a product of an in-cylinder pressure detected by the in-cylinder pressure sensor (15) and a value obtained by exponetiating an in-cylinder volume at timing of detecting the in-cylinder pressure with a predetermined index at two predetermined points during a period from opening timing of an intake valve (Vi) to closing timing thereof, and calculates a quantity of air aspirated into each combustion chamber (3) based upon a difference in the control parameter between the two predetermined points.

Abstract: An internal combustion engine (1) generates power by burning a mixture of fuel and air in each combustion chamber (3). The internal combustion engine (1) is provided with an in-cylinder pressure sensor (15) disposed in the combustion chamber (3) and an ECU (20). The ECU (20) calculates control parameters each of which is a product of an in-cylinder pressure detected by the in-cylinder pressure sensor (15) and a value obtained by exponetiating an in-cylinder volume at timing of detecting the in-cylinder pressure with a predetermined index at two predetermined points during a period from opening timing of an intake valve (Vi) to closing timing thereof, and calculates a quantity of air aspirated into each combustion chamber (3) based upon a difference in the control parameter between the two predetermined points.