Hitachi Construction Machinery Co., Ltd.

Hideki Haramoto

Shohei Kamiya

Yasushi Arai

Taku Kashu

Hidetoshi Satake

Kazuhiro Ichimura

Yukihiro Tatsuno

A fuel tank () is constructed such that a front flange portion (A) of a top surface plate (A) of a second plate () extends outside in relation to a front surface plate (B) of a first plate (). As a result, a front surplus space (A) projected in the upper and lower directions in a range of the front flange portion (A) of the top surface plate is formed in the front surface side of the front surface plate. A urea water tank () is arranged along the fuel tank () in such a manner that a rear side portion thereof enters into the front surplus space. Therefore, the rear side portion of the urea water tank can enter into the front surplus space using the front surplus space formed in the fuel tank (), thereby increasing the tank capacity without downsizing the article accommodating box ().

Construction machine

A urea water tank () is arranged in a cab () at which an operator boards, thereby making it possible to arrange urea water under a preferred temperature environment for preventing freeze and crystallization of the urea water. A water supply port (A) is provided to be opened to a left surface portion (C) of a cab box () constituting the cab () for supplying the urea water to the urea water tank () from an outside of the cab (). Therefore, even in a case of resupplying the urea water to the urea water tank (), an operator can easily resupply the urea water through a water supply hose () to the urea water tank () from the outside of the cab () without entering into the cab ().

The present invention includes: a hydraulic pumpthat is driven by a driving motor; a travel motion motorthat is driven with pressure oil supplied from the hydraulic pump; a travel motion control valvethat controls a flow rate of the pressure oil supplied from the hydraulic pumpto the travel motion motor; a means for operationwith which the travel motion control valveis operated; a means for rotation rate detectionthat detects a rotation rate N of the travel motion motor; and a means for motor over rotation preventionthat reduces the rotation rate of the travel motion motorif the means for rotation rate detectiondetects a rotation rate equal to or higher than a predetermined rotation rate upper limit Nmax.

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Kasumigaura, Japan

Hideki Haramoto