Hitachi Construction Machinery Co., Ltd.

Agency of Industrial Science and Technology Ministry of International

Hiroki Takeuchi

Shuuichi Meguriya

Shiho Izumi

Ryu Narikawa

Kouji Ishikawa

Teruki Igarashi

Tarou Akita

An articulated-type front work implement has a boom, an arm, and a bucket that are driven members coupled to each other; a boom cylinder, an arm cylinder and a bucket cylinder that are hydraulic actuators each of which drives a corresponding one of the plurality of driven members on the basis of an operation signal; a plurality of operation members each outputting the operation signal to one of the hydraulic actuators; and a controller that outputs the operation signal to at least one of the plurality of hydraulic actuators or executes area limiting control of correcting the output operation signal such that the front work implement moves on a target surface preset for a work target of the front work implement or within an area above the target surface, and corrects the operation signal on the basis of information related to operation of the hydraulic actuator.

Work machine

Provided is a work machine that can operate a front work implement at a speed according to an operator's lever operation while securing the accuracy of work by machine control. A hydraulic excavatorincludes a controllerthat sets a target surface for a bucketand controls the operation of a front work implementB in such a manner that the bucket does not penetrate to below the target surface. The controller sets a speed correction region on an upper side of the target surface, varies a width R of the speed correction region in accordance with an operation amount of an operation deviceA orC, and controls the operation of the front work implement in such a manner that the work tool does not penetrate into the speed correction region.

A controller outputs a first velocity (first limiting velocity) as a limiting velocity for a boom cylinder when a boom lowering operation amount is smaller than a first operation amount, and outputs a second velocity when the boom lowering operation amount is equal to or larger than the first operation amount. The first velocity is set to decrease according to a decrease in a target surface distance. The second velocity is defined by a weighted average of the first velocity and a third velocity (second limiting velocity) set to change according to one of the target surface distance and the boom lowering operation amount of the operation device, and is set such that an increase in the boom lowering operation amount reduces a weight for the first velocity while increasing a weight for the third velocity.

A work machine includes: control valves that control flows of a hydraulic operating oil supplied to actuators; operation lever devices that generate hydraulic signals to be output to the corresponding control valves according to an operation; solenoid proportional valves that reduce pressure of the hydraulic signals generated by the corresponding operation lever devices; and a front implement control section that controls the solenoid proportional valves. The work machine further includes: operation signal lines connected to the operation lever devices; signal input lines connected to the control valves; pressure reducing lines provided with the solenoid proportional valves; and selector valves that have a first position that interrupts connection of the operation signal lines and the pressure reducing lines and directly connects the operation signal lines to the signal input lines, and a second position that connects the operation signal lines to the signal input lines via the pressure reducing lines.

A work machine including a front control section configured to calculate a limit command value for restricting an operation of a front work implement includes: for example, a bypass line that bypasses, for example, the proportional solenoid valve in, for example, the pilot line; for example, a bypass valve disposed in, for example, the bypass line; a switch configured to output a signal to turn on or off control by the front control section; an on/off determining part configured to determine whether the signal from the switch is an on signal that brings front control into an on state or an off signal that brings the front control into an off state; an open/close command part configured to generate an open/close command signal to open the bypass valve when the signal is determined to be the off/off signal.

A multi-legged walking apparatus includes a first plurality of legs having a large weight support capacity and a second plurality of legs providing a large thrust force. The first plurality of legs provide a smaller thrust force than the thrust force of the second plurality of legs, and the second plurality of legs have a smaller weight support capacity than the weight support capacity of the first plurality of legs. The overall weight of the apparatus is supported substantially by the first plurality of legs, and the overall thrust of the apparatus is provided substantially by the second plurality of legs.

Growing community of inventors

Tsukuba, Japan

Hiroki Takeuchi