Abstract: A combustion type power tool capable of avoiding damage to seal members and a housing to prolong a service life, and capable of enhancing operability and workability. Temperature elevation of a combustion chamber frame due to combustion of a mixture of combustible gas and air is detected by a temperature sensor disposed in a housing. If the detected temperature exceeds a preset temperature, ignition of an ignition plug is prohibited by a prohibiting unit in spite of ON operation of a trigger switch. In this state, alarming is performed by a display to notify the user of the inoperable state of the tool. Similar control can be made when the temperature sensor is disposed at a cylinder, an exhaust cover and the housing.

Abstract: A combustion-powered, fastener-driving tool includes a cylinder and a combustion chamber disposed on top of the cylinder that accommodates a gaseous mixture of existing air in the combustion chamber and fuel injected therein. A spark plug generates a spark to combust the gaseous mixture in the combustion chamber. A trigger produces the spark in the spark plug when operated. A piston is movably supported in the cylinder and driven by combustion in the combustion chamber. A driving blade is coupled to the piston for driving a fastener. A spark controller is provided for generating a plurality of sparks in succession with the spark plug.

Abstract: A combustion-type power tool having a cooling arrangement for cooling a gas canister. The tool includes a housing having a gas canister accommodating section in which a gas canister is accommodated. An air passage is defined between the gas canister accommodating section and the gas canister accommodated therein. The gas canister accommodating section is formed with an air inlet port in communication with the air passage for introducing air into the air passage. Since air flows along the gas canister, the gas canister can be cooled. If the tool is provided with a fan, the rotation of the fan causes air suction passing through the air passage.

Abstract: A combustion-type power tool having a cooling arrangement for cooling a cylinder. The tool includes a housing, a cylinder head at one end of the housing, a push lever disposed at another end of the housing, and a combustion chamber frame including a base section and a head section. The head section has a disc like connecting portion extending from an end of the base section and a sleeve like abutment section extending from the connecting portion toward a cylinder head. A fan is disposed in a combustion chamber and is fixed to a rotation shaft of a motor supported to the cylinder head. The fan has fan blades. The fan blades define a widthwise center line in the axial direction of the rotation shaft. The center line is offset from the connecting portion and toward the push lever. The fan blades define widthwise edges in confrontation with the cylinder head. The widthwise edge is positioned in alignment with the connecting portion or offset therefrom toward the cylinder head.

Abstract: A combustion type power tool having a combustion chamber in which a fan is rotatably provided and an ignition plug is exposed. A combustible gas and air are mixed together by the fan, and the mixture is ignited by a spark generated at the ignition plug. As a result of combustion, gas expansion occurs to permit a piston and a driver blade to move for driving a fastener into a workpiece. A spark energy is set in a range of from 0.04 J to 0.08 J.

Abstract: A combustion type power tool having an arrangement avoiding direct striking of a drive shaft against a cylinder head when combustion pressure is exerted. A motor is disposed at the cylinder head and includes a motor body and a drive shaft extending in an axial direction and protruding into a combustion chamber. A fan is connected to the drive shaft to be rotatable within the combustion chamber. A buffer piece made from an elastic material is supported to the cylinder head. The buffer piece is movable relative to the cylinder head in a direction substantially perpendicular to the axial direction. The buffer piece is formed with a through-hole through which the drive shaft extends.

Abstract: A combustion-chamber frame is disposed in a housing of a combustion-type power tool and is movable in a longitudinal direction in interlocking relation to a push lever. The combustion-chamber frame is abuttable on a head portion to provide a combustion chamber in cooperation with the head portion and a piston. A fan is disposed in the combustion chamber and is connected to an output shaft of a motor so as to be rotatable with the output shaft for promoting turbulent combustion of air-fuel mixture. The fan and the combustion-chamber frame define, within the combustion chamber, a high turbulent-combustion region in which the turbulent combustion is rapidly generated and a low turbulent-combustion region outside the high turbulent-combustion region. A fin is disposed at at least one of the combustion-chamber frame, the head portion, and the piston to protrude into the combustion chamber. The fin is located within the low turbulent-combustion region.

Abstract: A combustion-type nail driver uses a motor for driving a fan. A motor holder formed from plastic accommodates the motor. A cylinder head has a motor holder receiving portion in which the motor holder is slidably movably disposed. A coil spring has one end secured to the motor holder and another end secured to the cylinder head to thereby support the motor holder. Initial acceleration applied to the motor when combustion occurs can be suppressed and impact imparted upon the motor can also be suppressed by friction between the outer periphery of the motor holder and the inner periphery of the motor holder receiving portion. A heat shielding plate is interposed between the lower end surface of the motor and the cylinder head in order to prevent hot air combustion gas from entering into the motor.

Abstract: A combustion type power tool having a motor suspension arrangement capable of buffering a shock applied to a motor. An integral buffer member made from an elastic material is fixed to a head cap. The buffer member includes a motor storage section in which a motor casing is stored, and a plurality of buffer segments extending radially outwardly from the motor storage section and integrally therewith. Each radially outer end portion of each buffer segment is fixed to the head cap for floatingly supporting the motor storage section.

Abstract: A combustion type power tool having a fan capable of providing a desirable turbulence in a combustion chamber. A fan is rotatably disposed in a combustion chamber and driven by a motor. The fan has fan blades each having a leading edge and a trailing edge. An angle of the leading edge relative to a rotational plane of the fan is approximately equal to an angle of the trailing edge relative to the rotational plane, whereby high degree of turbulence is generated from the position near the leading edge.

Abstract: A combustion-powered driving tool for driving nails or other fasteners in which the starting characteristics of a motor in the tool are improved by varying the amount of voltage applied to the motor when starting the motor and during normal operations so that the motor is driven to reach the rotational speed required in normal operations quickly. Therefore, the combustion-powered driving tool does not require the use of an expensive low-inertia motor, but can use a relatively inexpensive core-type motor or the like with inferior starting characteristics, while improving the work efficiency and user-friendliness of the combustion-powered driving tool.

Abstract: A combustion-powered driving tool for driving nails or other fasteners in which the starting characteristics of a motor in the tool are improved by varying the amount of voltage applied to the motor when starting the motor and during normal operations so that the motor is driven to reach the rotational speed required in normal operations quickly. Therefore, the combustion-powered driving tool does not require the use of an expensive low-inertia motor, but can use a relatively inexpensive core-type motor or the like with inferior starting characteristics, while improving the work efficiency and user-friendliness of the combustion-powered driving tool.

Abstract: A combustion type power tool capable of avoiding damage to seal members and a housing to prolong a service life, and capable of enhancing operability and workability. Temperature elevation of a combustion chamber frame due to combustion of a mixture of combustible gas and air is detected by a temperature sensor disposed in a housing. If the detected temperature exceeds a preset temperature, ignition of an ignition plug is prohibited by a prohibiting unit in spite of ON operation of a trigger switch. In this state, alarming is performed by a display to notify the user of inoperable sate of the tool. Similar control can be made when the temperature sensor is disposed at a cylinder, an exhaust cover and the housing.