Abstract: According to an aspect of the invention, an oil pulse tool includes: a motor generating a driving force according to a driving voltage; an oil pulse unit driven by the driving force and generating a torque in a pulse-like shape when the motor passes a strike position on a shaft thereof; and an output shaft on which a front end tool is mounted, the output shaft being connected to the shaft, characterized in that the oil pulse tool further comprises driving adjusting means to control the driving voltage, the driving voltage is reduced during a given period including a timing when the torque is transmitted to the output shaft, and the reduced driving voltage is increased when the given period is finished.

Abstract: According to an aspect of the invention, an oil pulse tool includes: a motor generating a driving force; an oil pulse unit including a shaft, the oil pulse unit being driven by the motor and generating an impact torque on the shaft when the motor passes an impact position; and an output shaft on which a front end tool is attached, the output shaft being fixed to the shaft, wherein the oil pulse tool is provided with a rotational position detecting sensor of detecting a rotational position of the output shaft, and a torque detecting sensor of detecting generation of an impact torque, and the oil pulse tool is provided with detecting means for measuring a state required for reversely rotating the motor by generating an impact, and regularly rotating again the motor and passing a position of generating the impact, and detecting a reduction in a performance of the oil pulse unit by an aging change of the state.

Abstract: A compact battery pack with high handling ability and restraining degradation of battery cells. The battery pack includes an insertion portion to be inserted into a handle portion of a cordless power tool and an accommodation portion in which all battery cells are accommodatable. A protection board with a protection circuit that protects batteries against overcharge and over-discharge is installed in the insertion portion. A switching element is connected between the battery cells and a drive motor of the power tool. An air passage in communication with the battery pack is formed within the handle and a main housing of the cordless power tool. The switching element is positioned at the air passage.

Abstract: A drilling device includes an end cutting tool, a main housing, a motor, a transmission, and a dust collection unit. The end cutting tool processes a workpiece. The motor is provided in the main housing for generating a torque. The transmission transmits the torque to rotate the end cutting tool. The dust collection unit collects dust generated by the rotation of the end cutting tool. The dust collection unit includes a dust case for accumulating the dust therein. The dust case is detachable from the main housing and has an inlet and an outlet. The inlet and the outlet are oriented in a single direction.

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: According to an aspect of the present invention, there is provided a power tool including: a motor that generates a rotational force; a power transmission mechanism that is driven by the motor to transmit the rotational force and that is connected to a bit; and a housing that houses the motor and the power transmission mechanism therein, wherein an electric fan for cooling the power transmission mechanism or the motor is provided inside the housing, wherein the power transmission mechanism, the motor and the electric fan are arranged in this order from front, and wherein the electric fan is disposed at a rear side so as to be interposed between the motor and a back wall of the housing.

Abstract: A portable cutter has a base member, a main body, a cutting blade, a protection member, a dust collection member, and a guide member. The base member moves on a workpiece, the base member having a shaft provided in proximity to one end thereof. The main body is coupled to the base member. A posture of the main body with respect to the base member is changeable. The cutting blade is attached to the main body and driven to cut the workpiece. The cutting blade has an outer periphery. The protection member covers a part of the outer periphery of the cutting blade. The dust collection member has an inlet provided in proximity to the outer periphery of the cutting blade for drawing and collecting dust. The guide member is pivotably supported to the shaft of the base member for guiding the dust to the opening of the dust collection member.

Abstract: According to the invention, a drilling tool includes: a motor; a transmission drive unit for transmitting a rotation force of the motor to rotate a drill bit; and a dust collector for collecting dust produced from a workpiece drilled by the drill bit, wherein the dust collector is provided with a pierced portion pierced by the drill bit, a dust collection port for sucking the produced dust and its surrounding air, and a blowoff port for blowing air against a vicinity of the piercing drill bit.

Abstract: According to the invention, a drilling tool includes: a driving source; a transmission drive unit for transmitting a rotation force of the driving source; and a dust collector for collecting dust produced from a workpiece drilled by the end tool and blowing air against the workpiece, wherein a filtering means for filtering the air mixed with the collected dust and a centrifugal fan for taking in the filtered air and sending out the filtered air in a circumferential direction are provided, the centrifugal fan is disposed in a housing formed with an airflow sending port for sending a part of the air taken in to the dust collector and a discharge port for discharging a rest of the air to an outside, and a distance from the airflow sending port to the discharge port in a forward direction in a direction of rotation of the centrifugal fan is longer than the distance from the airflow sending port to the discharge port.

Abstract: A blower providing a blower mode and a vacuum mode. A casing provides a motor housing installing a motor and a fan housing installing a centrifugal fan rotationally driven by the motor. A partition is disposed and having a first surface defining a motor housing and second surface defining a fan housing. The fan includes a generally circular base plate having one surface in direct confrontation with the second surface. A plurality of base plate through-holes arrayed in an imaginary circle whose center is coincident with the rotation axis of the fan are formed in the base plate. The partition is formed with a plurality of partition through-holes arrayed in the imaginary circle and in selective alignment with the base plate through-holes in accordance with the rotation of the centrifugal fan. Each partition through-hole includes a width increasing region where a width of the partition through-hole in the circumferential direction is gradually increased toward the second surface.

Abstract: A dust collection cover capable of efficiently collecting cutting chips and residues generated as a result of cutting a workpiece. A cutter includes a motor and a rotary blade driven by the motor, and the dust collection cover is attached to the cover for covering a part of the blade. The cover is formed with a dust discharge port through which cutting chips and residues are discharged. The cover has a guide arrangement for directing the cutting chips and residues toward an interior of the cover body. The arrangement provides a blowing-out air blowing to the workpiece, or a rod-like member removing the cutting chips and residues.

Abstract: A combustion-type power tool includes a housing, a cylinder head disposed at one end of the housing, a cylinder in the housing, a piston slidably disposed in the cylinder, and a driver blade connected to the piston. A combustion-chamber is provided in the housing, a fan is disposed in the combustion chamber, and a motor having an output shaft is coupled to the fan. A motor holder accommodates the motor, and the cylinder head is formed with a motor holder receiving portion in which the motor holder is slidably movably disposed. An elastic member is disposed in a gap formed between the motor holder and the motor holder receiving portion.

Abstract: A combustion-type power tool includes a housing having one end, a head portion disposed at the one end, and a cylinder disposed in the housing, the cylinder being formed with an exhaust hole. A piston is reciprocally movable in the cylinder, and a combustion-chamber frame is disposed in the housing and movable in an axial direction of the cylinder, the combustion-chamber frame being abuttable on the head portion to provide a combustion chamber in cooperation with the head portion and the piston. A fin is disposed on the cylinder and has a portion extending in a direction slanted in relation to the axial direction and oriented toward the exhaust hole.

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 capable of restraining reduction in output power due to lowering of combustion efficiency. A specific space within a combustion-chamber frame is enlarged. The specific space contains a specific region where high turbulence occurs in a combustion chamber at which a fuel is ignited. The enlargement is made by providing an enlarged distance between a rotation shaft of the fan and an inner wall of the combustion-chamber frame. When the turbulent combustion occurring at the specific region is expanded in the combustion chamber, flame propagation contour of the turbulent combustion reaches the wall of the combustion-chamber frame and ribs at a delayed timing. Therefore, after the turbulent combustion is sufficiently promoted, the flame reaches the combustion-chamber frame and the ribs. In other words, the flame does not reach the combustion-chamber frame and the ribs at the initial stage of turbulent combustion.

Abstract: A combustion-type power tool includes a housing, a head portion, a cylinder disposed in the housing, and a push lever. A piston is reciprocally movable in the cylinder, and a combustion-chamber frame is disposed in the housing and abuttable on the head portion to provide a combustion chamber in cooperation with the head portion and the piston. A fuel supplying portion supplies the fuel into the combustion chamber, a motor is disposed at the head portion, and a fan is disposed in the combustion chamber and connected to an output shaft of the motor so as to promote turbulent combustion of an air-fuel mixture. The fan and the combustion-chamber frame define a high turbulent-combustion region and a low turbulent-combustion region, a fin of one shape is located within the low turbulent-combustion region, and another fin of another shape has a part thereof located in the high turbulent-combustion region.

Abstract: A drilling device includes an end cutting tool, a main housing, a motor, a transmission, and a dust collection unit. The end cutting tool processes a workpiece. The motor is provided in the main housing for generating a torque. The transmission transmits the torque to rotate the end cutting tool. The dust collection unit collects dust generated by the rotation of the end cutting tool. The dust collection unit includes a dust case for accumulating the dust therein. The dust case is detachable from the main housing and having an inlet and an outlet. The inlet and the outlet are oriented in a single direction.

Abstract: A combustion-type power tool includes a housing, a cylinder, a cylinder head, a combustion chamber frame, and a rotatable fan. The combustion chamber frame including a base section, a head section abuttable on the cylinder head to provide a combustion chamber when the combustion chamber frame is at a first position, and a connection portion for connecting the head section with the base section. The fan includes fan blades which define a widthwise center line and having widthwise edge portions which define a widthwise edge line at a side of the cylinder head. The widthwise center line is offset from the connection portion toward another end of the housing, and the widthwise edge line is offset from the connection portion toward the cylinder head when the combustion chamber frame is at a second position.

Abstract: A power tool includes a brushless motor, a cooling fan, and a driving unit in a housing. The brushless motor is provided in the housing and having a rotary shaft. The cooling fan is attached to the rotary shaft in the housing, and rotatable together with the rotary shaft. The driving unit is provided in the housing for driving the motor. The driving unit includes an inverter circuit having a circuit board and a plurality of switching elements mounted on the circuit board. The circuit board is positioned on an opposite side to the motor with respect to the cooling fan. The plurality of switching elements is positioned around the cooling fan in a circumferential direction about the rotary shaft.

Abstract: A combustion-type power tool includes a housing, a cylinder disposed, a piston, and a cylinder head disposed at an end of the housing and having a wall portion extending in a direction perpendicular to an axial direction, the wall portion having an opening. A motor is disposed at the cylinder head and includes a motor body and a drive shaft extending from the motor body into a combustion chamber through the opening of the wall portion of the cylinder head, a fan is connected to the drive shaft to be rotatable within the combustion chamber, and an elastic member is disposed at the opening of the wall portion and has a sleeve portion extending in the axial direction. The sleeve portion has a through-hole through which the drive shaft extends, and an inner surface of the through-hole is tapered with respect to an outer surface of the drive shaft.