The present invention is directed to perform fine low-voltage control without largely increasing the circuit layout area in a low-power consumption structure. In the case of shifting a region to a low-speed mode, a system controller outputs a request signal and an enable signal to a power switch controller and a low-power drive circuit, respectively, to turn off a power switch and to perform a control so that the voltage level of a virtual reference potential becomes about 0.2 V to about 0.3V. The region operates on voltages between a power supply voltage and a virtual reference potential, so that it is controlled in the low-speed mode.

Semiconductor Integrated Circuit Device

The evaporative emission control system for an internal combustion engine purges the vapor collection canister to the intake manifold through a purge regulator controlled by the engine ECU. The purge regulator comprises a diaphragm valve and an electronic vacuum regulator. The purge regulator functions to allow a purge flow rate correlated with a control signal from the engine ECU and manifold vacuum, to maintain the purge flow rate substantially constant in response to certain changes in the magnitude of manifold vacuum, and to re-adjust the purge flow rate in correlation with changes in the control signal from the engine ECU. The diaphragm valve comprises a tapered valve element that progressively reduces the flow restriction as the valve element is increasingly opened.

Regulated flow canister purge system

A method of measuring barometric pressure with a manifold pressure sensor (62) in a microprocessor based engine control system utilizes known engine operating conditions to interrogate the sensor. Also on engine turn-off, a power latch signal (158) is generated to delay power removal until the throttle valve (160) is driven open and the pressure sensor (62) is interrogated for its value. This value at this time is the ambient or barometric value of pressure. This value is stored in the microprocessor's (26, 28) memory (84, 86) and maintained by means of a standby voltage (80). During engine operation, the pressure sensor (62) is interrogated and value of the stored barometric pressure is changed by one unit of pressure if the stored and measured values are unequal.

Measuring barometric pressure with a manifold pressure sensor in a microprocessor based engine control system

A reactive ion etching method is described in which a silicon compound film formed on an underlying layer or a substrate is etched through a mask layer by a two-stage procedure. In the two-stage procedure, part of the silicon compound film is first etched with a gas containing a hydrogen-free carbon fluoride gas at a high etching rated and then with a gas containing a hydrogen-containing carbon fluoride gas while reducing the damage on the underlying layer or substrate. The apparatus for carrying out the method is also disclosed.

Etching method and apparatus

An internal combustion engine provided with a device for cutting fuel during deceleration and a purge system for selectively opening and closing a fuel passageway from a charcoal canister to an intake system of the engine in accordance with the operating condition of the engine. The purge system is operated so that the passageway is closed when the fuel is cut, and the purge system is operated so that the passageway is opened and closed in accordance with the operating condition of the engine when the engine is in a deceleration condition other than the particular condition where the fuel is cut.

System for controlling vaporized fuel in an internal combustion engine

PURPOSE:To precisely set a pulse motor to the specified preset position under an open loop control status by regulating the air to fuel ratio in reference to couner readings corresponding exactly to real positons of the pulse motor which drives an air/fuel ratio regulation valve. CONSTITUTION:An air/fuel ratio control unit regulates air and fuel mixture produced in a carburetor 3 by means of a control circuit 20, which receives output signals from an O2 sensor provided in an exhaust system, and sends out signals to a pulse motor 13 so that an air/fuel ratio control valve can be regulated properly. Whereupon, the control circuit 20 is so constructed, as to shift during a feedback control the information on the reference position of the pulse motor 13 stored in a memory of the control circuit 20 to a real position counter at the instant when the pulse motor 13 passes a contact point of a lead switch 23, which detects the position of the pulse motor 13. Thus the air/fuel ratio control can be attained in reference to counter readings corresponding exactly to real positions of the pulse motor 13.

Air/fuel ratio feedback control unit for internal combustion engine

PURPOSE:To simplify the construction of the above-titled device and to lower the manufacturing costs of the same, by utilizing a sensor for detecting the temperature of engine cooling water that is used for the control of air-fuel ratio also as a sensor for detecting the low temperature state of engine that is used for controlling release of vaporized fuel from a canister to the venturi section. CONSTITUTION:An air-fuel ratio controlling system shown in the drawing controls the air-fuel ratio to an aimed value by way of feedback method by controlling the opening of a fuel-air ratio controlling valve 9 by ECU20 in response to the output of an O2-sensor. A canister 40 adsorbs vaporized fuel in a float chamber 4 and a fuel tank (no whoen) and release the vaporized fuel via a release control valve 47 and a release pipe 43 appropriately according to the circumstances. The valve 47 is controlled by negative pressure delivered from conduits 45, 46. In the above arrangement, the ECU20 gives a high-temperature signal to a solenoid valve 44 when the output of a sensor (thermistor) 33 for detecting the temperature of engine cooling water exceeds a prescribed value and closes the valve 44. At the same time, atmospheric pressure is introduced into a vacuum chamber 47a of the release control valve 47, so that the valve 47 is closed.

Device employed in internal combustion engine for preventing escape of vaporized fuel

PURPOSE:To attain the best emission characteristic, by compensating the open-loop position of a pulse motor, which drives an air fuel ratio control valve, depending on the change in the atmospheric pressure. CONSTITUTION:When starting control is finished, basic air fuel ratio control is started and an ECU20 drives a pulse motor 13 on the basis of the output signal V of an O2 sensor 28, the absolute pressure PB in an intake manifold indicated by a pressure sensor 31, the speed Ne of an engine indicated by rotational frequency sensors 35, 36 and the atmospheric pressure PA indicated by an atmospheric pressure sensor 29, to control the ratio of air to fuel. The basic air fuel ration control consists of open-loop control at the time of fuel open full opening of a throttle valve, open-loop control at the time of idling, open-loop control at the time of deceleration and closed-loop control under partial load. When the closed-loop control is to be changed for the open-loop control, the ECU20 stops the pulse motor 13 in a prescribed position compensated in terms of the atmosheric pressure.

Atmospheric pressure compensator for air fuel ratio controller of internal combustion engine

PURPOSE:To abate exhaust of noxious gases at the moment of zero starting, by shifting a pulse motor for driving an air fuel ratio control valve to a given position which is from hence to be the starting point of feedback control. CONSTITUTION:A feedback controller of air fuel ratio which drives an air fuel ratio control valve of a pulse motor 13 in accordance with an O2 sensor is equipped with an air fuel ratio discriminator 204, PI control circuit 203 and pulse motor driving units 209, 211 in an EPU20. An engine revolution discriminator 205a also set to the controller for processing output of engine revolution sensors 28, 29 provides an FF205c with an output from its terminal (b), as it monitors the state of acceleration at the moment of zero starting. An output (Q) from the FF205c actuates the PI controller 203 to interrupt feedback control and put out a pulse through a comparator 210 for shifting an air fuel ratio control valve to a given position.

Acceleration controller for air fuel ratio feedback control of internal combustion engine

PURPOSE:To prevent misfire due to temporary dilution of intake mixed gas from occurring by a method wherein a shot air valve is not operated temporarily when an engine starts. CONSTITUTION:A pulse signal Ne for the number of rotation of the engine detected by sensors 35, 36 for the number of rotation undergoes shaping of wave form in a wave form shaping part A1 comprising a circuit 205 for detecting the engine condition and is converted into a corresponding voltage value by an F-V converter A2. This voltage value is compared by a comparator B with the standard voltage value corresponding to the intended number NCR of rotation of the engine. When the number Ne of rotation exceeds the number NCR of rotation, the comparator B judges an initial explosion has occurred, makes an output signal and applies it to a timer circuit C. For an intended time after this signal is supplied, the circuit C transmits the output signal to an electromagnetic valve driving gear D, the gear D opens the electromagnetic valve and brings the shot air valve (not shown) to a standstill. After a given time passes the circuit C stops occurrence of the output signal and the shot air valve commences ordinary operations.

Ootsuka Kazuo

Papers

Air/fuel ratio feedback control unit for internal combustion engine

Device employed in internal combustion engine for preventing escape of vaporized fuel

Atmospheric pressure compensator for air fuel ratio controller of internal combustion engine

Acceleration controller for air fuel ratio feedback control of internal combustion engine

Controlling device of secondary air in suction air sistem of internal combustion engine