摘要:
A fuel supply apparatus for an engine in which calculation of a manipulated variable of a fuel pump in response to a deviation between a fuel pressure detected by a fuel pressure sensor and a target value is carried out, is configured in a manner such that when the fuel pressure sensor is failed, a change in the fuel pressure is estimated based on a required fuel flow amount of an engine, a discharge amount of the fuel pump and a fuel pressure detected immediately before the fuel pressure sensor is failed, so that deciding of the manipulated variable of the fuel pump is made, based on the estimation value. A method of controlling the fuel supply apparatus to realize the controlling of the fuel pump based on the manipulated variable is also disclosed.
摘要:
Predicting of starting of an engine is performed in advance before starting of the engine. When the starting of the engine is predicted, a failure diagnosis of a device such as a heater, a pump and so forth, which are attached to the engine and to be operated before starting of the engine, is made. When the heater and the pump are determined to be normal from the result of the diagnosis, the heater and the pump are operated before the engine is started. With this, the temperature of the heater can be increased and the pressure of a fluid carried by the pump can be increased before starting the starting of the engine.
摘要:
A leak diagnosing technology in which a diagnostic space capable of being closed is defined which includes therein a fuel tank and a canister, the closed diagnostic space being pressurized by an air pump to diagnose of presence or absence of a leak in the diagnostic space based on whether or not a pressure in the diagnostic space indicates a predetermined pressure change. When the diagnosis is completed, the air pump is reversely rotated to cause a reduction in the pressure in the diagnostic space to thereby quickly return the pressure to a target pressure in a steady state.
摘要:
In a fuel supply apparatus for an engine, which is provided with a relief valve for returning fuel in a fuel pipe into a fuel tank when a fuel pressure exceeds a threshold, and also feedback controls a discharge amount of a fuel pump so that the fuel pressure detected by a pressure sensor approaches a target pressure, when the pressure sensor is failed, a duty of a PWM signal for the fuel pump is fixedly maintained at a predetermined value, and fuel injection pulse width is calculated on the assumption that the fuel pressure is held at the threshold.
摘要:
Factors affecting the response time of a transfer system from the combustion of injected fuel to the detection of its oxygen concentration include a stroke delay time due to an engine speed, the dependence of an LAF sensor response time on an exhaust gas flow rate, a response time change of the LAF sensor due to its deterioration with time, and the like. If a hyperplane of the sliding mode is fixed without considering the above-mentioned factors affecting the response time of the transfer system, an overshoot or oscillation of a feedback system may occur at low speeds of the engine even if preferable feedback responsiveness can be achieved, for example, at high speeds of the engine. This results in aggravated exhaust emissions, degraded drivability due to torque fluctuations, and fluctuations in idle speed.A hyperplane used in a control system for providing feedback control of an air-fuel ratio through sliding mode control is varied based on the factors affecting the response time of the control system within a range in which the control system can be stabilized.
摘要:
In a fuel supply apparatus for an engine, which is provided with a relief valve for returning fuel in a fuel pipe into a fuel tank when a fuel pressure exceeds a threshold, and also feedback controls a discharge amount of a fuel pump so that the fuel pressure detected by a pressure sensor approaches a target pressure, when the pressure sensor is failed, a duty of a PWM signal for the fuel pump is fixedly maintained at a predetermined value, and fuel injection pulse width is calculated on the assumption that the fuel pressure is held at the threshold.
摘要:
A leak diagnosing technology in which a diagnostic space capable of being closed is defined which includes therein a fuel tank and a canister, the closed diagnostic space being pressurized by an air pump to diagnose of presence or absence of a leak in the diagnostic space based on whether or not a pressure in the diagnostic space indicates a predetermined pressure change. When the diagnosis is completed, the air pump is reversely rotated to cause a reduction in the pressure in the diagnostic space to thereby quickly return the pressure to a target pressure in a steady state.
摘要:
Predicting of starting of an engine is performed in advance before starting of the engine. When the starting of the engine is predicted, a failure diagnosis of a device such as a heater, a pump and so forth, which are attached to the engine and to be operated before starting of the engine, is made. When the heater and the pump are determined to be normal from the result of the diagnosis, the heater and the pump are operated before the engine is started. With this, the temperature of the heater can be increased and the pressure of a fluid carried by the pump can be increased before starting the starting of the engine.
摘要:
In an engine of a vehicle provided with a normally-closed solenoid valve in a fresh air induction port of a canister, in the case where a refueling cap is open when the engine is stopped, a control module operates in a usual-power consumption mode, and forces closing of the solenoid valve. In the case where the refueling cap is closed, the control mode shifts to a low-power consumption mode, and maintains the solenoid valve in the closed condition.
摘要:
In an engine of a vehicle provided with a normally-closed solenoid valve in a fresh air induction port of a canister, in the case where a refueling cap is open when the engine is stopped, a control module operates in a usual-power consumption mode, and forces closing of the solenoid valve. In the case where the refueling cap is closed, the control mode shifts to a low-power consumption mode, and maintains the solenoid valve in the closed condition.