Makita Corporation

Yoshitaka Ichikawa

Motohiro Omura

Kenya Yanagihara

Hirokatsu Yamamoto

Takuya Kusakawa

Ryunosuke Kumagai

Tokuo Hirabayashi

Yutaka Matsunaga

Yuki Kawai

Tadahiko Kobayakawa

Goshi Ishikawa

Akihiro Nakamoto

Katsuna Hayashi

Hayato Kano

Ying Yang

Hitoshi Suzuki

Yoshitaka Machida

Tomoyuki Kondo

Masahiro Watanabe

Yasuhito Kawai

Toru Yamada

Ryo Umemoto

Kunihisa Shima

Hiroshi Nojiri

Minoru Gyoda

Shinichi Hira

Junya Matsushita

Tatsuya Hata

A system in one aspect of the present disclosure includes a battery pack and an electric work machine. The battery pack includes a battery, a first interface, a first memory and a first controller. The first controller is configured to transmit battery data identifying a type of the battery pack. The electric work machine includes a motor, a second interface, a switching element, a manual switch, a second memory and a second controller. The second controller is configured to transmit electric apparatus data identifying a type of the electric work machine.

Technique for controlling discharge from battery pack

A battery pack is configured to supply electric power to an electric work machine, such as a power tool or outdoor power equipment. The battery pack includes a first battery-signal terminal and a second battery-signal terminal. The first battery-signal terminal outputs, to the electric work machine, a first signal indicating that discharging is to be prohibited or permitted. The second battery-signal terminal outputs, to the electric work machine, a second signal indicating that discharging is to be prohibited or permitted. Thus, two communication paths are provided for transmitting signals to permit or prohibit discharging of the battery pack.

Electric work machine and battery pack

An electric powered work machine in one aspect of the present disclosure includes a motor, a tool driver, a command receiver, a diagnosis circuit, and a result transmitter. The diagnosis circuit executes a failure diagnosis of the electric powered work machine in response to the command receiver receiving a diagnosis command signal from a diagnosis device. The result transmitter transmits a diagnosis result signal to the diagnosis device. The diagnosis result signal indicates a result of the failure diagnosis that is executed by the diagnosis circuit.

Electric powered work machine, job-site electrical system, and method of diagnosing electric powered work machine

An electric work machine (), such as a power tool, comprises a motor (), a manipulatable part () such as a trigger switch, and a control part (). The motor is energized with electric current supplied by a battery pack (). By manipulating the manipulatable part, the control part energizes the motor. The control part also acquires information concerning the state of the battery from the battery pack, and, if appropriate based on the information obtained from the battery pack, takes measures (such as limiting a discharge current) to restrain, delay and possibly avert the performance of a protection (discharge-prohibited) operation by the battery pack.

Electric work machine

An electric working machine in one aspect of the present disclosure includes a motor and a controller. The motor is configured to be electrically coupled to a battery pack and to be driven with electric power from the battery pack. The controller is configured to acquire an internal resistance information of the battery pack and to change control of the motor based on the internal resistance information acquired.

Electric working machine

An electric working machine includes an attachment portion, a motor, and a controller. Multiple types of tip tools are alternatively attached to the attachment portion. The motor drives the tip tool attached to the attachment portion. The controller has first start control and second start control. The controller is configured to execute the first start control so as to determine the type of the tip tool when not having tool type information, and configured to execute the second start control when having the tool type information.

Electric working machine capable of determining type of tip tool

One aspect of the present disclosure provides an electric working machine. The electric working machine includes a driver, a motor, and a control circuit. Attached to the driver is a selected tool. The motor drives the selected tool attached to the driver. The control circuit sets a target rotational frequency based on the selected tool. The control circuit controls the motor to rotate at the target rotational frequency.

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

An electric working machine in one aspect of the present disclosure includes two or more circuits and a control circuit. The control circuit executes two or more diagnoses one by one in order. The diagnoses at least include a first diagnosis and a second diagnosis. The first diagnosis diagnoses a first circuit. The second diagnosis diagnoses a second circuit. The control circuit executes the first diagnosis or the second diagnosis at a first diagnosis timing. The control circuit executes the first diagnosis or the second diagnosis at a second diagnosis timing. The second diagnosis timing follows the first diagnosis timing.

An electric working machine in one aspect of the present disclosure includes a motor, a controller, and a setter. The controller is configured to change a rotational state of the motor, in response to an establishment of a condition for change after the motor is initiated, from a low speed rotation to a high speed rotation. The setter is configured to set, based on a situation in the motor in the low speed rotation, a control variable of the motor in the high speed rotation and/or the condition for change.

Electric working machine and method of controlling rotational state of motor of electric working machine

An electric working machine of one aspect of the present disclosure includes a connection port, a control circuit, and/or a power supply switch. The power supply switch is provided on a power supply path extending from a battery pack connected to the connection port to the control circuit. The power supply switch maintains an ON state while a power supply permission signal is output from the battery pack to the electric working machine. The control circuit outputs an ON-command signal to the power supply switch for a specified period of time in response to loss of the power supply permission signal from the battery pack.

An electric power tool according to one aspect of the present disclosure includes a main body, a motor, a tool holder configured to hold a tool bit, a hammer, a motion converter, a rotation transmitter, a first load detector, a second load detector, and a motor controller. The first load detector detects, based on information indicating a drive state of the motor, a load imposed from a work piece to the tool bit. The second load detector detects, based on information indicating a behavior of the main body, a load imposed from the work piece to the tool bit. The motor controller sets an upper limit of rotational speed of the motor to a predetermined no-load rotational speed in response to no-load on the tool bit being detected by both the first load detector and the second load detector.

Electric power tool and method of controlling rotational speed of motor in electric power tool

An electric power tool in one aspect of the disclosure comprises an operation unit, a bridge circuit having a plurality of switching elements, and a control unit. The control unit is configured to select from the plurality of switching elements a pair of switching elements forming a current path of a motor. The control unit selectively executes one of non-complementary PWM in which one of the selected switching elements is turned on and the other turned on/off, and complementary PWM in which, in addition to the same control as that of the non-complementary PWM, a switching element connected to the same terminal of the motor as the other of the selected switching elements is turned on/off so that an on/off state of the switching element is reversed to that of the other of the selected switching elements.

Electric power tool

A work apparatus in one aspect of the present disclosure comprises a control unit, a volatile memory and a rewritable non-volatile memory. The control unit comprises an update processing unit and a writing processing unit. The writing processing unit writes history information in the volatile memory into the non-volatile memory when the writing processing unit predicts a suspension of supply of an electric power to the control unit.

Work apparatus, and method of rewriting history information thereof

An electric working machine in one aspect of the present disclosure comprises a motor, a first operation unit, a control unit, a second operation unit, and a storage unit. The storage unit stores a reference speed that is set via the second operation unit. The control unit drives the motor at a rotation speed corresponding to a drive command from the first operation unit, in accordance with a control characteristic that is set based on the reference speed stored in the storage unit.

Growing community of inventors

Anjo, Japan

Yoshitaka Ichikawa