Komatsu Corporation

Takumi Nagahara

Satoru Nishimura

Mitsuhiro Shimazu

Masamichi Ueda

Takanori Hata

It is a subject of the present invention to provide a hydraulic shovel concurrently used for crane operations in which an operator may immediately be ascertained of conditions during crane operations as well as dangerous conditions occurring on the implement or the vehicle body so that operations may be performed in a stable and rapid manner, this being achieved by a hydraulic shovel concurrently used for crane operations which comprises an implement including a boom, an arm, a bucket and a hook for enabling crane operations, which further comprises a monitor device including a monitor screen, wherein a parameter display portion for displaying parameters related to load factors of safe-working load, an engine condition display portion for displaying engine conditions and an alarm information display portion for displaying alarm information are provided on the monitor screen during crane operations, wherein a plurality of display items of the alarm information display portion may be sequentially switched and displayed, and wherein the parameter display portion is turned into an alarm color when the load factor for safe-working load is within a dangerous area.

Hydraulic shovel concurrently used for crane operations

A hoisting hook is arranged on a stick boom top pin for attaching a bucket to a distal end of a stick boom and hung at a bucket scooping face side. A bucket fall prevention valve is provided at least on a head side of a bucket cylinder for maintaining the cylinder inner pressure in order to prevent the bucket from free fall. A crane work by the hoisting hook is performed with the bucket dumped to the stick boom back side to the maximum extent. During the crane work, even if the hydraulic oil hose connected to the bottom side of the oil chamber of the hold pressure generation side of the bucket cylinder is broken by an external force, the bucket fall prevention valve acts instantaneously, cuts off the head side oil chamber from the exterior oil passage completely, and maintains the hold pressure of the head side oil chamber, so that the bucket is prevented from rotating suddenly downward. There is provided a hydraulic shovel allowing to perform a good crane work with an improved visibility of an operator, the bucket is prevented from free fall due to the lifted load, by securing the bucket cylinder hold force, and the crane work safety is improved.

Hydraulic shovel with hoisting hook

A speed control apparatus and method of a working vehicle which can reduce a working speed and a traveling speed of the vehicle to a desired speed range in correspondence to a change of working conditions at a time of a vehicle crane operation. A controller sets an optional hydraulic pump absorbing curve when an operator selects the crane operation mode. When the speed is adjusted by the operator, a pump tilt and rotation angle is automatically controlled to a pump absorbing torque in correspondence to the crane working speed along the optional pump absorbing torque curve.

Speed control apparatus of working vehicle and speed control method thereof

Various work machines in which safety of operation and operation efficiency can be enhanced in accordance with variation in the kind of operation and operation condition when operation is carried out based on a previously set operation mode of an operation machine, and operation speed of the operation machine or running speed of the work machine can finely be adjusted is provided. The work machine comprises mode switching means having a mode switching switch and the like of operation modes of one or more operation machines. A speed finely-adjusting switch is disposed for finely adjusting an operation speed and/or a running speed to values out of range set in each mode by manual operation. An engine, a pump, a flow rate adjusting valve disposed in a driving circuit of one or more operation machine and running motor and the like are operated by a signal output by operating the speed finely-adjusting switch, and the engine revolution number and the pump discharge amount are adjusted. Even under an environment in which operation range is changed or an obstruction may exist, it is possible to effectively obtain optimal operation mode of the operation machine suitable for the kind of operation which is carried out and operation condition and skill of an operator, and stable running performance and operability of the operation machine can be realized.

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Hirakata, Japan

Takumi Nagahara