Abstract: In a variable valve operating device for an internal combustion engine, which is capable of changing operation characteristics of an engine valve in accordance with a change in rotation speed of a camshaft, a high-speed cam (60) including a base circle portion which has the same radius as that of a base circle portion of a low-speed cam (59) and also including a high-level portion which has a protruding amount larger than that of a high-level portion of the low-speed cam (59) is supported on a camshaft (43A) having the low-speed cam (59) fixed thereto such that the high-speed cam (60) is rotatable relative to the camshaft (43A), at a position adjacent to the low-speed cam (59); a cam follower member (46) is supported by an engine main body (11) to be operable in a manner following one of the low-speed cam (59) and the high-speed cam (60); and a centrifugal clutch (61A) configured to connect the high-speed cam (60) to the camshaft (43A) while synchronizing the phase of the high-speed cam (60) with that of the

Abstract: In an apparatus for controlling a general-purpose internal combustion engine having an electronic control unit (ECU) mounted on an electronic circuit board installed near a body of the engine and being connectable to a load such as an operating machine that consumes power generated by the engine, there are equipped with a first temperature sensor installed on the board at a position remote from the body and a second temperature sensor installed on the board at a position closer to the body than the first temperature sensor. A warm-up time period is determined based on an output of the first temperature sensor and a difference between outputs of the first and second temperature sensors, and an engine speed is controlled to a predetermined operating speed when the determined warm-up time period has elapsed (S18, S22), thereby improving the fuel efficiency and preventing engine stall.

Abstract: In an apparatus for detecting condition of load connected to a general-purpose internal combustion engine, a first threshold value is compared with a sum obtained by adding a predetermined value to a detected throttle opening and changes the threshold value to the sum if the first threshold value is less than the sum and the engine is determined to be under first load condition if the throttle opening exceeds the threshold value. Next a second threshold value is compared with a difference obtained by subtracting change amounts of the engine speed and throttle opening and the engine is determined to be under second load condition if the difference exceeds the second threshold value, thereby enabling to accurately detect a condition of a load connected to the engine. Then the desired engine speed is changed in response to results of the determinations.

Abstract: In a variable valve operating device for an internal combustion engine, which is capable of changing operation characteristics of an engine valve in accordance with a change in rotation speed of a camshaft, a high-speed cam (60) including a base circle portion which has the same radius as that of a base circle portion of a low-speed cam (59) and also including a high-level portion which has a protruding amount larger than that of a high-level portion of the low-speed cam (59) is supported on a camshaft (43A) having the low-speed cam (59) fixed thereto such that the high-speed cam (60) is rotatable relative to the camshaft (43A), at a position adjacent to the low-speed cam (59); a cam follower member (46) is supported by an engine main body (11) to be operable in a manner following one of the low-speed cam (59) and the high-speed cam (60); and a centrifugal clutch (61A) configured to connect the high-speed cam (60) to the camshaft (43A) while synchronizing the phase of the high-speed cam (60) with that of the

Abstract: An oil level detecting device for detecting an oil level in an oil storing chamber formed in a crankcase of an engine includes a fan, a power generator and an oil level determination unit. The fan is rotated by an oil flow produced by dipping up oil for lubricating the engine. In response to rotation of the fan, the generator generates a corresponding amount of electric power on the basis of which the oil level determination unit determines the oil level.

Abstract: In an apparatus for controlling a general-purpose internal combustion engine having an electronic control unit (ECU) mounted on an electronic circuit board installed near a body of the engine and being connectable to a load such as an operating machine that consumes power generated by the engine, there are equipped with a first temperature sensor installed on the board at a position remote from the body and a second temperature sensor installed on the board at a position closer to the body than the first temperature sensor. A warm-up time period is determined based on an output of the first temperature sensor and a difference between outputs of the first and second temperature sensors, and an engine speed is controlled to a predetermined operating speed when the determined warm-up time period has elapsed (S18, S22), thereby improving the fuel efficiency and preventing engine stall.

Abstract: In an apparatus for detecting condition of load connected to a general-purpose internal combustion engine, a first threshold value is compared with a sum obtained by adding a predetermined value to a detected throttle opening and changes the threshold value to the sum if the first threshold value is less than the sum and the engine is determined to be under first load condition if the throttle opening exceeds the threshold value. Next a second threshold value is compared with a difference obtained by subtracting change amounts of the engine speed and throttle opening and the engine is determined to be under second load condition if the difference exceeds the second threshold value, thereby enabling to accurately detect a condition of a load connected to the engine. Then the desired engine speed is changed in response to results of the determinations.

Abstract: An oil level detecting device for detecting an oil level in an oil storing chamber formed in a crankcase of an engine includes a fan, a power generator and an oil level determination unit. The fan is rotated by an oil flow produced by dipping up oil for lubricating the engine. In response to rotation of the fan, the generator generates a corresponding amount of electric power on the basis of which the oil level determination unit determines the oil level.

Abstract: In a multipurpose engine throttle device having a throttle body disposed at an intake pipe of the engine and housing a throttle valve, a case is integrally attached to the throttle body and housing an electric motor moving the throttle valve, a speed reducer connecting an output shaft of the motor with the throttle valve, an electronic circuit board having an electronic control unit that controls operation of the motor and a connector mounted thereon, and a harness connecting the motor with the connector, thereby reducing in overall size by efficient layout of these components.

Abstract: In a multipurpose engine throttle device having a throttle body disposed at an intake pipe of the engine and housing a throttle valve, a case is integrally attached to the throttle body and housing an electric motor moving the throttle valve, a speed reducer connecting an output shaft of the motor with the throttle valve, an electronic circuit board having an electronic control unit that controls operation of the motor and a connector mounted thereon, and a harness connecting the motor with the connector, thereby reducing in overall size by efficient layout of these components.

Abstract: In a throttle device for a multipurpose internal combustion engine having a throttle valve connected to an electric motor and a carburetor, when an instruction to stop the engine is inputted, the electric motor is controlled to move the throttle valve in a fully closed position so as to stop the engine, and then to move the throttle valve in a fully opened direction. With this, throttle valve can be surely opened to facilitate restarting, and the occurrence of dieseling and run-on is prevented without providing a fuel cut valve to the carburetor. Further, a spring is provided to urge the throttle valve in an opening direction. With this, the response in opening the throttle valve is enhanced and the size of the motor is reduced.

Abstract: A control system for general-purpose spark-ignition internal combustion engine to be used for a portable generator, etc., having one or two cylinders and an actuator connected to the throttle valve to open or close the throttle value. In the system, an adaptive controller with a parameter identification mechanism is provided which receives a detected engine speed and a desired engine speed as inputs, and computes a command value to be supplied to the actuator, using an adaptive parameter identified by the parameter identification mechanism, such that the detected engine speed is brought to the desired speed. In the system, the desired engine speed is determined such that the desired engine speed per unit time is not greater than a prescribed value and the command value is determined to be within the upper and lower limits of the throttle value.

Abstract: The invention intends to downsize a general-purpose engine generator and make operability thereof easy. A backup battery (233) is provided for the generator (22). The battery supplies electricity to an electronic controlled device such as a fuel pump for starting the engine. When the engine (1) carries out a rating operation, electricity is supplied from the generator (22). When the engine speed in a low speed range, only a pump (15) is driven. When the engine speed is exceeds the low speed range, the pump (15) is stopped, and an injectors, (10) and (27) are driven to be prevented from lapping over each other. When the engine speed reaches a high-speed range, the pump (15) is again driven. Electricity consumption at a time of starting is restricted by driving the electronic controlled devices at different timings until the engine (1) operation becomes self-sustaining.

Abstract: In a throttle device for a multipurpose internal combustion engine having a throttle valve connected to an electric motor and a carburetor, when an instruction to stop the engine is inputted, the electric motor is controlled to move the throttle valve in a fully closed position so as to stop the engine, and then to move the throttle valve in a fully opened direction. With this, throttle valve can be surely opened to facilitate restarting, and the occurrence of dieseling and run-on is prevented without providing a fuel cut valve to the carburetor. Further, a spring is provided to urge the throttle valve in an opening direction. With this, the response in opening the throttle valve is enhanced and the size of the motor is reduced.

Abstract: The invention intends to downsize a general-purpose engine generator and make operability thereof easy. A backup battery (233) is provided for the generator (22). The battery supplies electricity to an electronic controlled device such as a fuel pump for starting the engine. When the engine (1) carries out a rating operation, electricity is supplied from the generator (22). When the engine speed is in a low speed range, only a pump (15) is driven. When the engine speed is exceeds the low speed range, the pump (15) is stopped, and an injectors (10) and (27) are driven to be prevented from lapping over each other. When the engine speed reaches a high-speed range, the pump (15) is again driven. Electricity consumption at a time of starting is restricted by driving the electronic controlled devices at different timings until the engine (1) executes a self-sustaining.

Abstract: A fault on the generator can be detected with the use of a simple arrangement. The output of the generator 12 which has multi-phase winding and is driven by an engine 11 is rectified and then converted by an inverter 133 into an alternating current at the frequency of a system before interconnected to the source of the system. After the engine 11 is started, the direct current voltage Vdc is monitored with a first fault monitor 40. When the direct current voltage Vdc rises up to a predetermined level, a connector relay 135 is closed. As the output of the inverter 133 is increased, the interconnection with the system source is enabled. After the interconnection, the direct current voltage and the output of the inverter are monitored with a second fault monitor 43. If the direct current voltage drops down to below the predetermined level before the output of the inverter reaches a rated level, the canceling and re-interconnection is repeated.

Abstract: A control system for general-purpose spark-ignition internal combustion engine to be used for a portable generator, etc., having one or two cylinders and an actuator connected to the throttle valve to open or close the throttle value. In the system, an adaptive controller with a parameter identification mechanism is provided which receives a detected engine speed and a desired engine speed as inputs, and computes a command value to be supplied to the actuator, using an adaptive parameter identified by the parameter identification mechanism, such that the detected engine speed is brought to the desired speed. In the system, the desired engine speed is determined such that the desired engine speed per unit time is not greater than a prescribed value. and the command value is determined to be within the upper and lower limits of the throttle value. In addition, the detected engine speed is smoothed and a gain for determining the convergence speed of the adaptive controller is determined appropriately.

Abstract: An automatic voltage-regulating system for an engine generator includes an output voltage detecting device for extracting a single-phase AC output voltage from an output winding wound around a stator to output a detection voltage, and a switching device for regularizing the output voltage to be substantially at a constant level by selectively conducting and cutting off of a field current supplied from an exciting winding wound around the stator to a field winding wound around a rotor. Depending upon whether the detection voltage is higher or lower than a predetermined value, the charged voltage of a condenser for smoothing a rectified output from the field winding is divided by a pair of voltage dividing resistors. A switch device is forcibly turned on by a detection voltage in response to the voltage at a connection point between the pair of resistors exceeding a predetermined voltage value, to thereby cause the smoothing condenser to be discharged.

Abstract: An automatic voltage-regulating system for an engine generator includes a rectifying circuit connected to an exciting winding, a smoothing condenser provided between plus-side and minus-side output terminals of the rectifying circuit, an output voltage detecting means for extracting a voltage generated in output windings to output a DC detection voltage, and a switching means provided between the other end of the field winding and the minus-side output terminal so as to enable switching between the break and conducting one from another in depending on a voltage detected by the output voltage detecting device.

Abstract: A fault on the generator can be detected with the use of a simple arrangement. The output of the generator 12 which has multi-phase winding and is driven by an engine 11 is rectified and then converted by an inverter 133 into an alternating current at the frequency of a system before interconnected to the source of the system. After the engine 11 is started, the direct current voltage Vdc is monitored with a first fault monitor 40. When the direct current voltage Vdc rises up to a predetermined level, a connector relay 135 is closed. As the output of the inverter 133 is increased, the interconnection with the system source is enabled. After the interconnection, the direct current voltage and the output of the inverter are monitored with a second fault monitor 43. If the direct current voltage drops down to below the predetermined level before the output of the inverter reaches a rated level, the canceling and re-interconnection is repeated.