Koki Holdings Co., Ltd.

Hitachi Koki Co., Ltd.

Toshinori Yasutomi

Takashi Ueda

Yoshiichi Komazaki

Kenji Kobori

Yutaka Ito

Shinichiro Sato

Jyun Enta

Shinki Ohtsu

Junichi Kamimura

Sotaro Aizawa

Yuki Mitoma

Kazuhiko Funabashi

Hironori Mashiko

Shigetoshi Ishida

Seiichi Kodato

Shinichirou Satou

Koji Shioya

Jun Enta

Tatsuhiro Tago

A driver including: an ejection part to which a fastener is supplied; a driver blade which moves from a first position toward a second position and drives the fastener into a driven member; and a rack provided to the driver blade. The driver further includes: a rotary component engaging with the rack and moving the driver blade from the second position to the first position; and a lock plate engaging with the rack. The driver blade moves from the second position to the first position while the rotary component rotates once, the rotary component is released from engaging with the rack after the driver blade moves from the second position to the first position, and moves from the first position to the second position, and the lock plate is engageable with the rack when the driver blade stops before reaching the second position from the first position.

Driver

In a driver machine, a blank firing prevention mechanismhas a feeder position sensorthat detects the prohibition position of a feederof a magazine. When a control unitdetects the prohibition position of the feederon the basis of a detection signal from the feeder position sensor, the control unitprohibits driving of a motor. Thus it is possible to prevent blank firing of a striking part. The feeder position sensoris provided to an ejection part. Thus it is unnecessary for a wire, which connects the control unitand the feeder position sensor, to be extended to the outside of a housing, in comparison with a structure in which the feeder position sensoris provided in a magazine caseof the magazine

Work machine

A driving device capable of reducing the load in any of the plurality of engaging members is provided. The driving device includes an ejection unit to which a fastener is supplied, a striking unit configured to strike the fastener, a rack provided on the striking unit, a wheel provided rotatably, and a plurality of pins provided on the wheel and engaged with and released from the rack, wherein the plurality of pins can change positions in the wheel, and the plurality of pins include a pin located at a first position where the pin can be engaged with the rack and a pin which is located behind the pin in a rotation direction of the wheel and located at a second position where the pin cannot be engaged with the rack when the striking unit is actuated in the direction of striking the fastener.

Driving device

A working tool includes a magazine unit in which a plurality of connected fasteners are stored in a rolled shape, an ejection unit to which the fastener is fed, a driver blade configured to strike the fastener held in the ejection unit to one side in a first direction, an electric motor configured to drive the driver blade by receiving an electric power, a feeder unit capable of moving in a second direction crossing the first direction and configured to feed the fastener stored in the magazine unit to the ejection unit by moving to one side in the second direction, a solenoid configured to drive the feeder unit by receiving an electric power, and a control unit configured to allow the solenoid to drive when a load of the electric motor satisfies a first condition.

Working tool

A driving tool includes: a striking unit striking a fastener by being actuated in a first direction; a rack on the striking unit; a wheel; and a second transmission portion on the wheel and capable of being engaged with and released from the rack. The striking unit can be actuated in a second direction when the second transmission portion is engaged with the rack, and the striking unit can be actuated in the first direction when the second transmission portion is released from the rack. The second transmission portion includes: a tooth portion arranged along a rotation direction of the wheel and turned in a predetermined direction to be engaged with and released from the rack; and a movable piece actuated in the predetermined direction to be engaged with the rack and actuated in a different direction from the predetermined direction to be released from the rack.

Driving tool with rotating member to move striking unit

A driver capable of achieving favorable workmanship at the time of driving of a fastener into a workpiece to be driven is provided. In a driver having a striking unit; a first bias unit causing the striking unit to strike a fastener; a first operational unit and a second operational unit, and a control unit moving the striking unit in a first direction, the control unit can select a first driving mode, a second driving mode and a limitation mode, the first driving mode moving the striking unit in the first direction so that the fastener is struck when the first operational unit is operated after the second operational unit is pressed against the workpiece to be driven, the second driving mode moving the striking unit in the first direction so that the fastener is struck when the control unit detects the operation of the first operational unit and the pressing of the second operational unit against the workpiece to be driven, and the limitation mode limiting the second driving mode on the basis of a movement state of the striking unit.

A driver includes a pressure chamber, a striking portion, an operation member, and a contact member, and can select a first mode and a second mode. The driver further includes a first ventilation passage, a second ventilation passage, and opening/closing mechanisms. The opening/closing mechanisms have a first state to open the first ventilation passage and close the second ventilation passage in the first mode, a second state, when an operation force is applied to the operation member within a time from when the second mode is selected and the contact member contacts a workpiece, to close the first ventilation passage and open the second ventilation passage, and a third state, when an operation force is applied to the operation member within a time from when the second mode is selected and the contact member is separated from the workpiece, to close the second ventilation passage.

A fastener driving machine provided with a mechanism to lubricate pins or racks is realized. A fastener driving machine includes a driver blade, pins, and a lubricant feeding mechanism. The driver blade can reciprocate in a first direction and a second direction opposite to each other, and hits a fastener when the driver blade moves in the first direction. The pins respectively engage with racks provided on the driver blade to move the driver blade in the second direction. The lubricant feeding mechanism supplies lubricant to the racks and the pins.

Fastener driving machine

To provide a driver that can be reduced in the amount of gas to be injected into a pressure chamber. The driver has: an impactor configured to hit a stopper by moving from a first position toward a second position; a pressure chamber to be filled with gas for moving the impactor from the first position toward the second position; a control mechanism configured to move the impactor from the second position toward the first position; and a gas injection portion configured to inject gas into the pressure chamber, wherein the impactor is capable of taking a standby position between the second position and the first position, and the control mechanism is configured to stop the impactor at an adjustment position closer to the second position than the standby position before gas is injected into the pressure chamber.

An engine-driven work machine including: a two-cycle engine including a piston which is configured to reciprocally move inside a cylinder to which an exhaust port is formed; and a front end tool configured to be driven by the engine, wherein an expansion chamber is connected to the exhaust port via a connection duct, wherein the connection duct includes a first end and a second end, and the connection duct extends from the first end in an axial direction of the exhaust port, is bent in a direction away from an axis of the exhaust port and is connected to the expansion chamber at the second end, and wherein a housing of the expansion chamber is disposed at an inner side of the connection duct and an engine block including the cylinder and a crank case.

Muffler and engine-driven work machine

The invention provides a two cycle engine which effectively suppresses an intrusion of a combustion gas into a crank chamber. Further, the invention provides a two cycle engine tool provided with the two cycle engine mentioned above. An engine is provided with a cylinder having two scavenge air ports at different positions in a cylinder circumference direction, and scavenge air inflow ports communicating individually with these two scavenge air ports via a scavenge air passage, and a piston in which two scavenge air communication ports are formed at positions corresponding to the scavenge air inflow ports, and is structured to swirl the gas flowing into the piston from the cylinder through the scavenge air passage, in an upper portion of the internal space of the piston, and retains the gas in the upper portion of the internal space of the piston.

Two cycle engine and two cycle engine tool

A two cycle engine has an exhaust port provided in a side portion of a cylinder, and a scavenge air port provided in the side portion of the cylinder so as to be symmetrical with a plane passing through a center in a cylinder circumference direction of the exhaust port and an axis extending to inside of the cylinder, the scavenge air port is structured such that an axis extending to inside of the cylinder from an opening of the scavenge air port extends in such a direction as to be away from the exhaust port of the cylinder, and is divided in a cylinder axis direction by a dividing portion.

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Ibaraki, Japan

Toshinori Yasutomi