Makita Corporation

Itsuku Kato

Yuki Kawai

Hitoshi Suzuki

Katsuna Hayashi

Tomoyuki Kondo

Tokuo Hirabayashi

Motohiro Omura

Akira Tomonaga

Kouichi Takeda

Yasutaka Hotta

Hidenori Nagasaka

Takeshi Kamiya

Yasuhito Kawai

Goshi Ishikawa

Akihiro Nakamoto

Jiro Suzuki

Seitaro Hayashi

Masayuki Okamura

Dai Suzuki

An electric working machine in one aspect of the present disclosure calculates an estimated heat value based on an electric current value and a parameter. The estimated heat value corresponds to an estimated heat generation amount of a motor. The electric current value corresponds to a magnitude of an electric current delivered from a power source to the motor. The electric work machine varies the parameter based on a load time. The load time corresponds to a time period during which a first load is continuously imposed on the motor. The first load has a specified magnitude or more. The electric work machine performs a protective operation for over temperature protection of the motor based on the estimated heat value having reached a heat threshold.

Technique for protecting motor in electric work machine from over temperature

An electric work machine according to one aspect of the present disclosure includes a motor, a first connector, a second connector, an energizing circuit, a manual switch, and a controller. The controller outputs a first control signal to the energizing circuit to electrically connect the first connector to the motor, increases an actual rotational speed of the motor at a first rate, outputs the first control signal to the energizing circuit to electrically connect the second connector to the motor, and increases the actual rotational speed at a second rate. The second rate is less than the first rate.

Electric work machine

The electric work machine in one aspect of the present disclosure includes an output shaft, a motor, a current measuring circuit, and a controller. The current measuring circuit measures a current value, the current value corresponding to a magnitude of a drive current flowing through the motor. The controller sets a maximum value and a threshold. The controller calculates the correction value less than or equal to the maximum value so that the drive current decreases, in response to the current value having reached the threshold. The controller subtracts, from the control parameter, the correction value calculated, thereby correcting the control parameter. The controller drives the motor based on the control parameter corrected.

An electric work machine includes a motor, a first connector, a second connector, an energizing circuit, a manual switch, and a controller. The controller electrically disconnects the first connector from the motor based on a first voltage value below a first threshold at a start of motor rotation. The controller maintains an electrical connection of the first connector to the motor based on the first voltage value below the first threshold and equal to or greater than a second threshold during discharge of the first battery.

An electric work machine (), such as a power tool, includes a motor () having a rotor, a drive part () that supplies electric currents to drive the motor, a rotational-direction selection part (), and a motor-control part (). The rotational-direction selection part is configured for manually setting (selecting) the rotational direction of the rotor and outputs first and second setting signals that each indicate the set (selected) rotational direction. The motor-control part controls the drive part such that the rotor rotates in the rotational direction indicated by the first setting signal and/or the second setting signal. In response to a determination that the rotational directions indicated by the first and second setting signals are inconsistent, the motor-control part stops or prevents the drive of the motor.

An electric power tool in one aspect of the present disclosure includes a motor, an impact mechanism, an impact detector, and a control circuit. The control circuit controls a motor current based on a drive duty ratio in a first driving term. The first driving term corresponds to a time period from when the motor is started until impact is detect. The drive duty ratio corresponds to a sum of a basic duty ratio and a proportional duty ratio. The control circuit controls the motor current so that an actual rotational speed of the motor is consistent with a target rotational speed after elapse of the first driving term.

Electric power tool, and method for controlling motor of electric power tool

An electric power tool in one aspect of the present disclosure includes a motor, an impact mechanism, and a control circuit. The control circuit executes a motor control process. The motor control process includes limiting an output of the motor in response to establishment of a preset condition. The preset condition is based on a load applied to the motor.

Electric power tool

An interlocking adapter in one aspect of the present disclosure includes a current path, an electric load, a switch, and a controller. The controller turns on and off the switch in synchronization with a change of an alternating-current voltage received from an electric outlet of an electric apparatus in response to reception of an interlocking command signal from a working machine so as to supply a load current from the electric outlet to the electric load. The controller turns on and off the switch at a specified ratio of a time every &#xbd; cycle of the alternating-current voltage.

Interlocking adapter, and method for operating electric apparatus in interlocking manner with working machine

An electric working machine according to one aspect of the present disclosure comprises a motor, a rectifier circuit, a capacitor, a series switching element, a resistive element, a drive circuit, a peak voltage value acquirer, and a controller. The capacitor smooths power rectified by the rectifier circuit. The series switching element is coupled in series with the capacitor. The resistive element is coupled in parallel with the series switching element. The controller brings the series switching element into conduction in a case where AC power is inputted to the rectifier circuit and where a specified conducting condition based on a peak voltage value acquired by the peak voltage value acquirer is satisfied.

Electric working machine and method for smoothing AC power supplied thereto

An electric working machine in one aspect of the present disclosure includes: a motor; a controller for controlling driving of the motor; a first setter; and a second setter. The first setter is operated for setting, as a control method for the motor, which is usable by the controller, one of control methods preliminarily registered. The second setter is operated for setting, as a control method for the motor, which is usable by the controller, at least one of the control methods settable via the first setter.

Electric working machine

An electric working machine in one aspect of the present disclosure includes: a motor, a manipulator, a setter, and a controller. The setter sets first control characteristics preliminarily registered. The first control characteristics are set to achieve a rotational speed of the motor from a minimum rotational speed to a maximum rotational speed with a manipulating range of the manipulator, which is 50% or less of an effective manipulating range thereof.

Electric working machine and method for controlling motor of electric working machine

An electric power tool may include a three-phase brushless motor configured to drive a tool, a gear reducer provided between the motor and the tool. The gear reducer is configured to selectively change a reduction ratio from the motor to the tool between a first reduction ratio and a second reduction ratio. The electric power tool may further include a motor controller configured to drive the motor with rectangular waves. The motor controller is configured to selectively change a conduction angle of each rectangular wave between at least a first conduction angle and a second conduction angle.

A push cart includes a wheel, a motor, an obstacle detector, and a controller. The motor is configured to generate a rotational force that rotates the wheel. The obstacle detector is configured to detect an obstacle. The controller is configured to execute, in response to detection of the obstacle by the obstacle detector, avoidance control to control driving of the motor such that a movement of the push cart is limited. The controller is configured to disable execution of the avoidance control in response to a determination that a specified disabling condition is satisfied.

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Anjo, Japan

Itsuku Kato