Abstract: A driving machine capable of performing replenishment of air in a pneumatic chamber includes: a housing; a cylinder provided within the housing; a pneumatic chamber spatially connected to the cylinder; a piston reciprocally movably provided in the cylinder; a blade attached to the piston and striking a stopper; and a moving mechanism reducing an internal volume of either the pneumatic chamber or the cylinder by a motor, and the driving machine drives the stopper by repulsive force of compressed air. The driving machine has a pressure accumulating mode in which the pneumatic chamber is pressurized by the motor from a state where the pneumatic chamber communicates with outside, and a striking mode in which the piston is moved by the motor from a bottom dead point to a top dead point in the cylinder and then from the top dead point toward the bottom dead point, thereby driving the stopper.
February 19, 2016
February 8, 2018
Hitachi Koki Co., Ltd.
Yoshiichi KOMAZAKI, Mayumi UMINO, Yuki MITOMA, Shinichirou SATO
Abstract: A power tool includes a housing, a motor, an output unit, and a circuit board unit. The motor is accommodated in the housing and has a rotational axis extending in a top-bottom direction. The output unit is disposed above the motor and extends in a front-rear direction. A power cable is configured to be connected to a power source and is connected to the circuit board unit. The circuit board unit is accommodated in the housing. The circuit board unit comprises a switching element for driving the motor, and a rectifying device configured to rectify an alternating current from the power source to a direct current. The circuit board unit is disposed below the motor and extends in the front-rear direction in the housing.
Abstract: An electric working machine including: a housing to which a battery is configured to be detachably mounted, wherein the housing is configured such that a weight unit including a weight can be mounted to the housing.
Abstract: An engine is configured so that a muffler is affixed to the exhaust opening of the cylinder, and the air-cooled cylinder is cooled by a cooling fan. The engine is provided with a muffler cover for covering the muffler, and exhaust gas is discharged inside the muffler cover along the wall surface of the muffler. A second cooling air is combined with the exhaust gas flow from the upstream side thereof to be parallel thereto, and a first cooling air having been caused to flow under the muffler is caused to perpendicularly impinge against the exhaust gas flow on the downstream side thereof. Thus, the cooling airs are combined inside the muffler cover with the exhaust gas flow, and as a result the temperature of the exhaust gas is sufficiently reduced at the time when the exhaust gas is discharged from the opening of the muffler cover to the outside.
Abstract: The temperature of exhaust gas discharged from a compact air-cooled engine used as a power source for an engine-driven working machine is reduced. An engine has a muffler mounted directly to the exhaust opening of the cylinder, and a resin muffler cover covering the muffler. An exhaust gas restriction member is provided to a wall surface of the muffler, and two exhaust passages serving as outlets for exhaust gas are formed in the exhaust gas restriction member. The exhaust passages are arranged independent of each other, and the streams of discharged exhaust gas are discharged to be slightly separated from each other as the streams flow away from the exhaust openings. The separated streams of discharged exhaust gas form a negative pressure space between the streams promoting the introduction of a cooling air stream into the negative pressure portion. Thus, the temperature of the exhaust gas can be reduced.
Abstract: A brushless motor is incorporated in one of divided constituent members of a motor casing which is disassembled, and then, the divided constituent members of the motor casing which is disassembled are connected to each other into the motor casing assembled with mgachine screws screwed into machine screw holes. As this occurs, when a wiring of the brushless motor is held by a first stationary blade portion and a second stationary blade portion, the wiring is allowed to lead to an outside of an outer cylindrical portion through a gap defined between the first stationary blade portion and the second stationary blade portion.
Abstract: In the present invention, a housing having a trunk part accommodating therein a brushless motor and an output part to which a tip tool is to be connected, a handle part having one end connected to the trunk part, and an accommodation part provided at an other end of the handle part is used, and a FET serving as a switching element that supplies power to the motor is accommodated in the accommodation part from which a power supply cord is pulled out. It is possible to reduce the length of the trunk part in the front-rear direction compared to a case where the FET is disposed in the front-rear direction of the motor.
Abstract: An electric tool including: a motor configured to drive a front end tool; a control device configure to control rotation of the motor; a storage part configured to store a method of driving the motor by the control device; and a communication terminal to which a communication line for reading or writing information of the storage part is configured to be connected.
Abstract: In order to provide an electric tool with good operability that can extend the life of and suppress breakage of a switching element for controlling energization of a brushless motor, a control unit (50), after an operation switch (5) is turned off, does not immediately turn off an inverter circuit (43) (does not set the duty of a PWM signal to 0), and instead normally operates the inverter circuit (43) with a low-duty PWM signal and waits until a rotation speed of a brushless motor (6) reaches a predetermined rotation speed or less to turn off the inverter circuit (43) (to set the duty of the PWM signal to 0).
November 27, 2015
November 30, 2017
HITACHI KOKI CO., LTD.
Hironori MASHIKO, Kazutaka IWATA, Yuta NOGUCHI
Abstract: A laminar-scavenging two-cycle engine which has a high laminar-scavenging effect, includes a scavenging passage having a crankcase side portion extending along a crankcase, and a cylinder side portion extending along a cylinder and having a length larger than the sum of the diameter and stroke of the cylinder. An ambient air introducing passage for introducing leading air into the scavenging passage is connected to an intermediate portion of the scavenging passage. A notch for opening a scavenging port to the side of the crankcase when a piston is near the top dead center is formed in the piston.
Abstract: An impact tool includes a casing (13) supporting a tip tool (12), a piston (41) provided in the casing (13), an electric motor (11) provided in the casing (13), a motion converting mechanism (45) provided in the casing (13), and a vibration reducing mechanism (47) provided in the casing (13). The vibration reducing mechanism (47) has a supporting member, which is swingable with using a fixing position (J) as a supporting point and a weight (49) attached to a free end side of the supporting member. In a plane including a center line (C), the gravity center (H) of the weight (49) and the gravity center (G) of the casing (13) are disposed at mutually different locations, and the fixing position (J) is disposed on the side of the gravity center (G) relative to the center line (C).
Abstract: A portable electric cutter includes a housing 2 in which a motor 1 is accommodated, a saw blade driven to rotate by the motor, a base 6 coupled to the housing 2 and having a bottom surface slidable on a surface of a material to be cut, a fan 7 driven to rotate by the motor, a driving circuit for switching power supplied to the motor, and a control circuit for controlling the driving circuit. A circuit board 60 on which the driving circuit, the control circuit and others are mounted is provided, motor cooling air vents are provided in the housing 2 on a side opposite to the saw blade, and circuit board cooling air vents are provided in the housing 2 on the side opposite to the saw blade.
Abstract: A powered working machine (10) with which the transmission of vibrations from a housing to a control substrate can be suppressed, operates a distal tool using power from a brushless motor (30), is configured to have: a control substrate (71) that controls the brushless motor (30); a substrate case (82) that accommodates the control substrate (71); a motor housing (20) and cover (160) that support the substrate case (82); an elastic body (152) that is disposed between the substrate case (82) and the motor housing (20); and an elastic body (153) that is disposed between the substrate case (82) and the cover (160).
October 21, 2015
November 2, 2017
Hitachi Koki Co., Ltd.
Yuta NOGUCHI, Kazutaka IWATA, Kazuhiko FUNABASHI, Tomoaki SUDO, Ken INUI, Naoki TADOKORO
Abstract: An electric power tool includes: a brushless motor having a plurality of stator windings and configured to rotate in accordance with voltages applied to the plurality of stator windings, an induced voltage being generated in accordance with a rotation of the brushless motor; a rectifier circuit configured to rectify an AC voltage; a smoothing capacitor configured to smooth the AC voltage rectified by the rectifier circuit to a pulsation voltage having a maximum value larger than the induced voltage and a minimum value smaller than the induced voltage; and an inverter circuit configured to perform switching operations to output the pulsation voltage to the plurality of stator windings by rotation.