Hitachi Koki Co., Ltd.

Koki Holdings Co., Ltd.

Atsuyuki Kikuchi

Masato Sakai

Takeshi Taniguchi

Hitoshi Tsuzuki

Tsukasa Suzuura

Shingo Yamazaki

Akihisa Yahagi

Kuniaki Kanbe

Shinichi Kakefuda

Tomoyuki Kawahara

Hiroyuki Hasegawa

Hideyuki Hashimoto

Hiroshi Haga

Mutsuo Harada

Satoshi Abe

Tomoya Ikeda

Daijiro Tanabe

Takahiro Ookubo

Takehiro Ookubo

Sinki Ohtsu

An electric power tool has a brushless motor for driving a tip tool, and a motor case is at least partly covered by a motor housing made of aluminum alloy and exposed to an outside. A control board provided with a control circuit for controlling the rotation of the brushless motor is disposed adjacent to the motor housing. The brushless motor and a control board are cooled by cooling air generated by a fun, thereby enhancing the cooling characteristics of the motor control circuit.

Power-actuated tool

Provided is an impact tool which can perform control in accordance with working situations. The impact tool converts a torque of a brushless motor into a striking force and applies it to a tip tool. The impact tool includes: a motor control unit which makes detection about whether the tip tool is pressed against an object during the rotation of the brushless motor; and a motor control unit which performs speed increase control for increasing the rotational speed of the brushless motor when a state of pressing the tip tool against the object has been detected continuously for a predetermined time.

Impact tool

Hammer

A reciprocating tool () includes a housing (), a driving source (), a reciprocation conversion unit (), &#x2014;and a vibration reduction mechanism (). The driving source is accommodated in the' housing. The reciprocation conversion unit () is supported by the housing and is configured to convert a driving force of the driving source into a reciprocating motion for providing a tool bit () movably supported to the housing with a reciprocating motion. The vibration reduction mechanism () includes a shaft (), a weight (), a support member (), and a urging portion (). The shaft i()s supported by the housing and extending in a direction perpendicular to directions of the reciprocating motion of the tool bit () t and has an axis. The weight () is located away from the shaft () and is swingable in a swinging direction. The support member () swingably supports the weight () about the axis of the shaft (). The urging portion () urges the weight () toward a prescribed position of the weight in the swinging direction with respect to the housing.

Reciprocating tool

An elastic unit includes a transatory unit including a first elastic support member, a second elastic support member and not-shown four round bar-shaped elastic bodies made of rubber. A rotation urging unit is composed of a Neidhart spring including an outer frame, a shaft, a rotary member, and four rubber rods. The rotary member is in a state where it is rotated at 10&#xb0; counterclockwise from an initial state. Therefore, the rubber rod deforms upon reception of rolling friction from the outer frame and the rotary member, and the rotation urging unit gives the handle portion the urging power by which the handle portion is rotated so that one end of the handle portion is spaced away from a gear housingin the direction of the handle portion.

Power tool

Portable electric hammer drill

Portable electric hammer

A projected portion provided at a cylinder and projected in a radius direction is formed at an end face thereof on a side of a tool holding portion, and a holding portion on one side of holding portions for holding an outer periphery of the cylinder by at least two portions remote from each other in an axial direction to position in the radius direction of the cylinder is configured by a guide face having an inner diameter of a dimension substantially the same as an outer diameter of the projected portion and extended over to a contact face brought into contact with the projected portion from an end face of a cylinder case on a side of the tool holding portion.

Striking tool

In a percussion tool such as an electric hammer or a hammer drill in which the axial direction of a motoris substantially perpendicular to that of a tool bitattached to a tool holder, a motor housingis made of a hard material such as aluminum, and a tail coveris disposed on the lower end of the motor housing, projectionsandwhich project beyond the tail coverare disposed.

Percussion tool

A hammer holder, provided between a retainer sleeve and a cylinder, slidably holds an intermediate member in an axial direction. A predetermined clearance is maintained between the hammer holder and the retainer sleeve. The hammer holder has a recessed portion which is engageable with a flange of the intermediate member so as to restrict the slide movement of the intermediate member. A cushioning member receives a percussion force when the flange is stopped by the recessed portion. The clearance restricts a compression amount of the cushioning member so that a predetermined life of the cushioning member is assured.

Growing community of inventors

Ibaraki, Japan

Atsuyuki Kikuchi