Hitachi Koki Co., Ltd.

Tomoyoshi Yokota

Kenichi Matsunaga

Seiichi Kodato

Shinichi Sakamoto

Katsuhiro Oomori

Chikai Yoshimizu

Hiroki Kitagawa

Masahiro Miura

Tadayoshi Mineta

Kenichi Kato

Tomomasa Nishikawa

Shingo Kosugi

Shinji Kuragano

Teruo Imai

Yoshimi Takahashi

Satoru Gunji

Masanori Okada

Hideyuki Tanimoto

Kazutaka Iwata

Shinichi Kakefuda

Atsushi Nakagawa

Kenichirou Yoshida

Naoto Ichihashi

Kenji Niwa

Kazuhiro Segawa

Hirokazu Yoshida

Tetsuo Ebata

An air compressor comprising: a tank (), a compression mechanism (), a motor () and a control circuit (). The control circuit () includes a CPU () and a storing unit () which stores a control program, the compressor operation history and a plurality of operation modes. Each of the operation modes is defined by two setting values: a reference restart pressure value and a motor rotational speed value, at least one of these values being different from among the plurality of modes. The control circuit () executes one of the plurality of modes as a target mode in which the control unit controls the motor to restart by comparing the pressure in the tank with the reference restart pressure and rotates the motor at the rotational speed of the target mode. The control circuit changes the target mode from the one of the plurality of modes to another one of the plurality of modes based on the compressor operation history.

Air compressor

An air compressor includes a compression unit, a drive unit, a tank unit, and a control circuit unit. The compression unit is configured to generate a compressed air and provided with a handle positioned above a center of gravity of the air compressor. The drive unit is configured to drive the compression unit. The tank unit is disposed below the compression unit and includes a plurality of air tanks configured to reserve the compressed air. The compressed air reserved in the tank unit has a pressure value. The control circuit unit is configured to detect the pressure value of the compressed air reserved in the tank unit and to control the drive unit to drive the compression unit.

A portable cutter has a base member, a main body, a cutting blade, a protection member, a dust collection member, and a guide member. The base member moves on a workpiece, the base member having a shaft provided in proximity to one end thereof. The main body is coupled to the base member. A posture of the main body with respect to the base member is changeable. The cutting blade is attached to the main body and driven to cut the workpiece. The cutting blade has an outer periphery. The protection member covers a part of the outer periphery of the cutting blade. The dust collection member has an inlet provided in proximity to the outer periphery of the cutting blade for drawing and collecting dust. The guide member is pivotably supported to the shaft of the base member for guiding the dust to the opening of the dust collection member.

Portable cutter

An air compressor includes a motor, an air compression mechanism driven by the motor, a rotation shaft rotatable integrally with a rotor of the motor, a fan rotatable integrally with the rotation shaft, a plurality of air tanks for reserving compressed air generated by the air compression mechanism, and a control unit for controlling the motor. The plurality of air tanks are juxtaposed with each other and arrayed in an array direction. The plurality of air tanks includes an endmost air tank and an adjacent air tank adjacent to the endmost air tank. The control unit is disposed adjacent to and opposite to the adjacent air tank relative to the endmost air tank. The control unit is disposed adjacent to and in confrontation with an outer circumference of the fan.

According to the invention, an air compressor includes: one pair of air tanks arranged parallel to each other by being separated from each other in a constant interval, for storing thereinto compressed air; a compressing unit that compresses air sucked from an external space so as to supply the compressed air to the air tanks; and a motor coupled to the compressing unit so as to drive the compressing unit, while the motor and the compressing unit are arranged above the one pair of air tanks; wherein: a cooling fan that generates cooling wind is provided on one end of a rotation shaft of the motor; and a control circuit unit that drives the motor is arranged above the one pair of air tanks and at a position which is overlapped with an axial direction projection area of the cooling fan.

When an air pressure in a tank part () drops from a maximum set pressure value (A) to or below at least one restart set pressure value defined to lie in a range between the maximum set pressure value and a minimum set pressure value, a control circuit part () operates an electric motor () at a predetermined revolving speed. When the air pressure in the tank part () drops from the restart set pressure value to or below the minimum set pressure value, the control circuit part () operates the electric motor () at the predetermined revolving speed or a revolving speed lower than Nuntil the air pressure in the tank part () reaches the maximum set pressure value.

A first coil includes a first inner-coil bundle and a first outer-coil bundle. The first outer-coil bundle is positioned radially outwardly of the first inner-coil bundle in a radial direction of a stator core. A second coil includes a second inner-coil bundle and a second outer-coil bundle. The second outer-coil bundle is positioned radially outwardly of the second inner-coil bundle. A first inner-coil end and a first outer-coil end form a gap and a groove. A second inner-coil end and a second outer-coil end also form a gap and a groove.

Electric tool having electric motor with first and second coils having first and second coil bundles of different innermost peripheral length

A power tool has a handle holder portion having a semispherically bulging outer circumference, and an arm portion enclosing the handle holder portion and having a semispherically recessed inner circumference. The bulging outer circumference of the handle holder portion is fitted in the recessed inner circumference of the arm portion. An elastic member is clamped between a power tool body and a handle around the handle holder portion in the radial direction perpendicular to the center axis of the protruding direction of the handle holder portion. A bulging portion for limiting the sliding range of the arm portion is disposed at the leading end of the handle holder portion.

Power tool

A commutator motor includes a stator and a rotor, and the stator includes a stator yoke and a field magnet. The field magnet is fixed onto the inner peripheral surface of the substantially cylindrical stator yoke. The stator yoke is configured by coaxially stacking a plurality of plate-like annular bodies, and the annular bodies are fixedly connected to each other by caulking at a caulking portion disposed on the annular body. In manufacture, the length of the stator yoke in the axial direction can be arbitrarily changed with the thickness of the annular body in the axial direction as a minimum unit. In case of manufacturing various stator yokes that are different in the axial length, the necessity of replacing a manufacturing machine is eliminated, thereby providing a commutator motor having the stator yoke which is low in the manufacturing costs.

Commutator motor

In a circular saw, an end plate provided on an end of a rotor core has a cylindrical shaft insulator and a plate extending radially from the shaft insulator. The plate is disposed at a position separated from the end of the rotor core. The plate includes slot parts, and air holes that penetrate the plate in the axial direction of the rotor shaft at areas adjacent to the rotor shaft. Protruding parts are provided on the shaft insulator on both sides of each air hole, extending in the axial direction of the rotor shaft and protruding radially outward with respect to the rotor shaft. The shaft insulator has an outer diameter Dthat is smaller than a diameter Dof the plate in the slot parts adjacent to the rotor shaft.

Electric motor and electric tool having the motor

In the portable electrical circular saw (electrical tool) in which a commutator motor (permanent magnet motor) is mounted in a motor case (housing) which is integrally formed in a tube shape, the commutator motor includes a stator fixed to an inner circumferential surface of the motor case and a rotor which is rotatably disposed in the stator, and a plate having a plurality of protrusions is disposed on at least one of the both axial ends of a rotor core of the rotor, an outer diameter of at least two protrusions of the plate is larger than an outer diameter of the rotor core and smaller than an inner diameter of the stator.

Electrical tool

A power tool includes a brushless motor, a cooling fan, and a driving unit in a housing. The brushless motor is provided in the housing and having a rotary shaft. The cooling fan is attached to the rotary shaft in the housing, and rotatable together with the rotary shaft. The driving unit is provided in the housing for driving the motor. The driving unit includes an inverter circuit having a circuit board and a plurality of switching elements mounted on the circuit board. The circuit board is positioned on an opposite side to the motor with respect to the cooling fan. The plurality of switching elements is positioned around the cooling fan in a circumferential direction about the rotary shaft.

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Hitachinaka, Japan

Tomoyoshi Yokota