A neat-fuel direct-injected compression ignition engine having a thermal barrier coated combustion chamber, an injection port injects fuel that satisfies a stoichiometric condition with respect to the intake air, a mechanical exhaust regenerator transfers energy from exhaust gas to intake compression stages, an exhaust O.sub.2 sensor inputs to a feedback control to deliver quantified fuel, a variable valve actuation (VVA) controls valve positions, an exhaust gas temperature sensor controls exhaust feedback by closing the exhaust valve early according to the VVA, or recirculated to the chamber with an exhaust-gas-recirculation (EGR), heat exchanger, and flow path connecting an air intake, a load command input, and a computer operates the EGR from sensors to input exhaust gas according exhaust temperature signals and changes VVA timing, the load control is by chamber exhaust gas, the computer operates a fuel injector to deliver fuel independent of exhaust gas by the O.sub.2 signals.

A neat-fuel direct-injected compression ignition engine having a thermal barrier coated combustion chamber, an injection port injects fuel that satisfies a stoichiometric condition with respect to the intake air, a mechanical exhaust regenerator transfers energy from exhaust gas to intake compression stages, an exhaust O.sub.2 sensor inputs to a feedback control to deliver quantified fuel, a variable valve actuation (VVA) controls valve positions, an exhaust gas temperature sensor controls exhaust feedback by closing the exhaust valve early according to the VVA, or recirculated to the chamber with an exhaust-gas-recirculation (EGR), heat exchanger, and flow path connecting an air intake, a load command input, and a computer operates the EGR from sensors to input exhaust gas according exhaust temperature signals and changes VVA timing, the load control is by chamber exhaust gas, the computer operates a fuel injector to deliver fuel independent of exhaust gas by the O.sub.2 signals.

The invention provides an exhaust purification device capable of suppressing the temporal decrease in NOx catalyst removal efficiency due to soot accumulation. The invention provides an exhaust purification device using an air injection nozzle to inject pressurized air into a casing of a catalyst reactor containing an NOx catalyst as a catalyst and removing soot adhering to the NOx catalyst, wherein it is determined and externally notified that there is abnormal deterioration in the NOx catalyst when the pressure difference P in exhaust between the upstream and downstream sides of the NOx catalyst has increased by at least a first reference pressure difference increase Pt1, which is the allowable amount of pressure difference increase, above the pressure difference Pi in exhaust between the upstream and downstream sides of the catalyst in the initial state at the same exhaust flow rate Ve.

A neat-fuel direct-injected compression ignition engine having a thermal barrier coated combustion chamber, an injection port injects fuel that satisfies a stoichiometric condition with respect to the intake air, a mechanical exhaust regenerator transfers energy from exhaust gas to intake compression stages, an exhaust O.sub.2 sensor inputs to a feedback control to deliver quantified fuel, a variable valve actuation (VVA) controls valve positions, an exhaust gas temperature sensor controls exhaust feedback by closing the exhaust valve early according to the VVA, or recirculated to the chamber with an exhaust-gas-recirculation (EGR), heat exchanger, and flow path connecting an air intake, a load command input, and a computer operates the EGR from sensors to input exhaust gas according exhaust temperature signals and changes VVA timing, the load control is by chamber exhaust gas, the computer operates a fuel injector to deliver fuel independent of exhaust gas by the O.sub.2 signals.

A neat-fuel direct-injected compression ignition engine having a thermal barrier coated combustion chamber, an injection port injects fuel that satisfies a stoichiometric condition with respect to the intake air, a mechanical exhaust regenerator transfers energy from exhaust gas to intake compression stages, an exhaust O.sub.2 sensor inputs to a feedback control to deliver quantified fuel, a variable valve actuation (VVA) controls valve positions, an exhaust gas temperature sensor controls exhaust feedback by closing the exhaust valve early according to the VVA, or recirculated to the chamber with an exhaust-gas-recirculation (EGR), heat exchanger, and flow path connecting an air intake, a load command input, and a computer operates the EGR from sensors to input exhaust gas according exhaust temperature signals and changes VVA timing, the load control is by chamber exhaust gas, the computer operates a fuel injector to deliver fuel independent of exhaust gas by the O.sub.2 signals.

A neat-fuel direct-injected compression ignition engine having a thermal barrier coated combustion chamber, an injection port injects fuel that satisfies a stoichiometric condition with respect to the intake air, a mechanical exhaust regenerator transfers energy from exhaust gas to intake compression stages, an exhaust O.sub.2 sensor inputs to a feedback control to deliver quantified fuel, a variable valve actuation (VVA) controls valve positions, an exhaust gas temperature sensor controls exhaust feedback by closing the exhaust valve early according to the VVA, or recirculated to the chamber with an exhaust-gas-recirculation (EGR), heat exchanger, and flow path connecting an air intake, a load command input, and a computer operates the EGR from sensors to input exhaust gas according exhaust temperature signals and changes VVA timing, the load control is by chamber exhaust gas, the computer operates a fuel injector to deliver fuel independent of exhaust gas by the O.sub.2 signals.

The invention provides an exhaust purification device capable of suppressing the temporal decrease in NOx catalyst removal efficiency due to soot accumulation. The invention provides an exhaust purification device using an air injection nozzle to inject pressurized air into a casing of a catalyst reactor containing an NOx catalyst as a catalyst and removing soot adhering to the NOx catalyst, wherein it is determined and externally notified that there is abnormal deterioration in the NOx catalyst when the pressure difference P in exhaust between the upstream and downstream sides of the NOx catalyst has increased by at least a first reference pressure difference increase Pt1, which is the allowable amount of pressure difference increase, above the pressure difference Pi in exhaust between the upstream and downstream sides of the catalyst in the initial state at the same exhaust flow rate Ve.