Koki Holdings Co., Ltd.

Hitachi Koki Co., Ltd.

Takuya Yoshinari

Kazuhiko Funabashi

Toshiaki Koizumi

Yuji Kishima

Haruhisa Fujisawa

Hideyuki Tanimoto

Kazutaka Iwata

Takao Aradachi

Eiji Nakayama

Yoshikazu Kawano

Yasushi Nakano

Yukihiro Shima

Shinji Kuragano

Takafumi Itoh

Naoto Ichihashi

Hironori Mashiko

Takeru Kumakura

Yuki Horie

Hironori Sakai

Jyun Enta

Naoto Wakatabe

Takafumi Itho

Provided is a rotary tool. In the rotary tool, the rotating tip tool is mounted on a spindle by the fixture, and the spindle and the tip tool are rotated by a motor. The rotary tool has a switch which can switch the motor between a rotation state and a stop state, and a control device which controls the rotation of the motor corresponding to the operation of the switch. When the switch is turned off after a required time T elapses after the motor is started, the control device stops the rotary tool () by performing a common braking operation on the spindle, and when the switch is turned off before the required time T elapses after the motor is started, the control device stops the tip tool () by inertia without applying a braking force.

Rotary tool

A DC power supply device includes a first conversion unit connected to an AC power supply, a second conversion unit connected to an electric tool, and a cable connecting the first conversion unit and the second conversion unit to each other. The first conversion unit includes a power factor correction circuit, converts an AC voltage having a first voltage value, input from the AC power supply, into a DC voltage having a second voltage value higher than the first voltage value, and outputs the DC voltage having the second voltage value to the cable. The second conversion unit converts the output voltage of the first conversion unit, input via the cable, into a DC voltage having a third voltage value lower than the second voltage value, and outputs the DC voltage having the third voltage value to the electric tool.

DC power supply device

An electric tool capable of achieving inhibition of reaction due to braking in good balance with inhibition of voltage jumping due to regenerated energy is provided. A grinder () is provided with a motor (), an inverter circuit () for supplying electric current to the motor (), and a controller () for controlling the inverter circuit (). When generating an electric braking force on a motor (), the rotation speed of which exceeds a specified rotation speed, the controller () performs a first braking control of continuously turning on lower arm-side switching elements (Q-Q) of the inverter circuit (), after which the controller performs a second braking control of repeatedly turning on and off the lower arm-side switching elements (Q-Q).

Electric tool

A DC power supply device includes a housing including a wall portion, a first opening and a second opening, a circuit portion, a regulation wall portion, and a fan. The first and second openings are formed in the wall portion. The circuit portion includes first and second circuit elements those fixed within the housing. The regulation wall portion provide a first air passage in communication with the first opening, a second air passage in communication with the second opening, and a bent air passage allowing the first air passage and the second air passage to communicate with each other. The fan is configured to generate an air-flow flowing between the first air passage and the second air passage. The fan is positioned to face the first opening. The first circuit element is positioned in the first air passage. The second circuit element is positioned in the second air passage.

Provided is a DC power supply device If an electrical tool () of a rated voltage of 36 V is connected to the DC power supply device () (if the voltage of a lower positive terminal indicates the presence of a short bar), a microcomputer () performs control so as to switch a switching element (Q) on and output a DC voltage of 36 V between an upper positive terminal and the upper negative terminal. If an electrical tool () of a rated voltage of 18 V is connected to the DC power supply device () (if the voltage of the lower positive terminal indicates the absence of a short bar), the microcomputer () performs control so as to switch a switching element (Q) on and output a DC voltage of 18 V between the upper positive terminal and the upper negative terminal.

Provided is an electric tool capable of continuing work by making the electrical advance angle of a brushless motor changeable even when a load is heavy. The electric tool is provided with: a brushless motor; a controller for controlling the drive of the brushless motor; and an inverter circuit supplied with a pulsation voltage obtained by rectifying an AC power supply input in a full-wave manner and electrifying the brushless motoraccording to a control signal of the controller. The controller can change the electrical advance angle of the brushless motor. The controller detects the motor current flowing through the brushless motor and increases the electrical advance angle when the motor current reaches a predetermined threshold value.

Provided is a power tool capable of performing braking in which deterioration and breakage of elements are inhibited. In a brake control, an arithmetic unit: performs a switching control of a combination of any of upper arm side Q-Qswitching elements and any of lower arm side switching elements Q-Qwhile sequentially switching the elements; and causes a current to flow in a closed loop (a closed loop in the same direction as during driving of the power tool) in order through any of the upper arm side Q-Qswitching elements, stator coils, any of the lower arm side switching elements Q-Q, and a first diode bridge

Power tool

In order to provide an electric tool such that the capacitances of noise-suppressing film capacitors can be increased without increasing the diameter of a handle section, the housing of the electric tool comprises: a body section that stores a brushless motor, a striking mechanism part, and a portion of an output part; a handle section, whose one end is connected to the body section; and a storage section that is formed on the other end of the handle section. A pair of film capacitors for removing noise generated from an inverter circuit are mounted on a capacitor substrate and stored side by side inside the handle section. The film capacitors are connected in parallel with each other, thereby providing a capacitor having a larger total capacitance than before.

In order to provide a tool in which a motor is assuredly prevented from being restarted when power is turned on again after a power supply interruption due to a contingency, a disk grinderincludes a motorand a switchswitchable between an ON position at which the motor is driven by an operator and an OFF position at which the motor is stopped. Furthermore, first and second restart prevention meansare provided to disable driving of the motor until the switch is turned again to the ON position when power supplied to the motorfalls below or under a predetermined value.

Power Tool

A power tool includes a brushless motor, a rectifier circuit configured to rectify an AC voltage supplied from an AC power supply and output a rectified voltage, an inverter circuit configured to perform switching actions with respect to the rectified voltage to be supplied to the brushless motor, a controller configured to control the switching actions of the inverter circuit, a trigger having an operating part being operable by a user, a switch rendered ON and OFF in accordance with an operation performed in the operating part, wherein when the switch is ON, the inverter circuit is electrically connected to the AC power supply whereas when the switch is OFF, and the inverter circuit is electrically disconnected from the AC power supply, and a power supply circuit connected between the switch and the AC power supply and configured to supply a voltage to the controller.

A power tool includes: a brushless motor; a rectifier circuit; a smoothing circuit; an inverter; a controller; an operating part; and a switch. The switch is rendered ON in accordance with an operation performed in the operating part by a user to allow power to be supplied to the inverter circuit by the rectifier circuit through the smoothing circuit and rendered OFF in accordance with release of the operation by the user to interrupt the inverter circuit from the rectifier circuit to halt supplying the power to the inverter circuit. The smoothing circuit includes a first capacitor and a second capacitor connected in parallel. The controller is configured to control the switching operations of the inverter circuit to drive the brushless motor in accordance with a signal inputted in accordance with the operation performed in the operating part by the user.

A backpack-type power supply includes: a plurality of cell units () each configured of a plurality of secondary battery cell (); a case () configured to accommodate the cell units and having first and second contacts; and a harness () attached to the case, characterized by including; first connecting means () for electrically connecting the first contact and a positive terminal of each cell unit to form a first electrical path therebetween; and second connecting means () for electrically connecting the second contact and a negative terminal of each cell unit to form a second electrical path therebetween, each first electrical path and each second electrical path forming a total electrical path having a total resistance for each cell unit, the total resistance of each total electrical path being adjusted such that heat distribution is substantially uniform over the plurality of cell units in the case.

Backpack-type power supply

The backpack-type power supply includes a rechargeable battery, a case, a harness, and an operation unit. The case accommodates the rechargeable battery. A user wears the case on a back of the user by the harness. The operation unit includes at least one of a switch and a display unit. The switch is configured to enable or disable the rechargeable battery. The display unit is configured to display a battery level of the rechargeable battery.

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Hitachinaka, Japan

Takuya Yoshinari