Hitachi Construction Machinery Co., Ltd.

Akinori Ishii

Mariko Mizuochi

Kunitsugu Tomita

Kenji Hiraku

Juri Shimizu

Teppei Saitoh

Jinichi Yamaguchi

Kazuo Fujishima

Hiromasa Takahashi

Kazuyoshi Hanakawa

Satoshi Nakamura

Saku Egawa

Yasuhiko Kanari

Shuuichi Meguriya

Eiji Egawa

Takashi Kusama

Takahiro Inada

A haulage vehicle includes a body, a load measurement device that measures a mounted load value of the body, a traveling electric motor, and a travel control device that outputs an electric motor command value, the travel control device sets a backward movement limiting set value to ON when it is determined that the haulage vehicle is in execution of either loading work or dumping work, and sets the backward movement limiting set value to OFF when a forward position signal and an accelerator pedal command value are inputted, an electric motor command value formed of a backward movement limiting command value is outputted to the traveling electric motor when the backward movement limiting set value is ON, and an electric motor command value formed of a normal command value is outputted to the traveling electric motor when the backward movement limiting set value is OFF.

Haulage vehicle

A work assist system for a self-propelled hydraulic excavator includes a controller () configured to determine a region in which an assumed excavation amount is obtained from an object to be excavated by one excavation operation of the hydraulic excavator () as a region to be excavated S on the basis of the assumed excavation amount in the one excavation operation of the hydraulic excavator (), and to calculate a work position Pw of the hydraulic excavator () at which the hydraulic excavator () performs a next excavation operation on the basis of the region to be excavated S. A distance Lw from the hydraulic excavator to the work position Pw is calculated by the controller () and this distance Lw is displayed on the monitor ().

Work assist system for work machine

A loadage correction system includes a loading-weight measuring unit that measures a loading weight of a work object loaded by a loader, a loadage measuring unit that measures loadage of the work object loaded on a transporter from the loader, a communication unit that performs data transfer of measurement results obtained in the loading-weight measuring unit and the loadage measuring unit, a difference calculating unit that calculates a difference between the measurement results of the loading-weight measuring unit and the loadage measuring unit input from the loading-weight measuring unit and the loadage measuring unit, a difference storing unit that stores a difference calculation result, a correction-target determining unit that determines the loading-weight measuring unit or the loadage measuring unit, the measurement result of which needs to be corrected, from the loading-weight measuring unit and the loadage measuring unit, and a correction-value calculating unit that calculates a correction value for the loading-weight measuring unit or the loadage measuring unit.

Loadage correction system

A drive control system for a work machine. A gradual stoppage command and an operation speed limitation command are calculated and output. A pilot pressure is corrected such that, upon a stoppage operation of a control lever, a drive actuator is stopped gradually; and the pilot pressure is corrected such that an operation speed of the drive actuator is limited. A supply of the pilot hydraulic fluid to the speed increasing unit is interrupted when a failure of a speed increasing solenoid proportional valve of the speed increasing unit is detected.

Drive control system for work machine

The work machine includes a stabilization control calculation unit that calculates and outputs a gradual stoppage command for making a drive actuator stop gradually and an operation speed limitation command for limiting an upper limit operation speed according to the status of stability of the work machine, a stoppage characteristic modification unit that corrects pilot pressure so as to make the drive actuator stop gradually when a stoppage operation is performed on a control lever, and an operation speed limitation unit that corrects the pilot pressure so as to limit the operation speed of the drive actuator.

Work machine

To provide a hydraulic driving device configured to smoothly extend a hydraulic cylinder. The present invention includes the open circuit E, the closed circuit A, a control device, and a control lever. The open circuit E is provided with a flow passagefor connecting an outlet port of the open circuit pumpand a head chamberof the boom cylinder, a selector valveprovided in the flow passage, a discharge flow passagefor connecting a hydraulic fluid tankand a flow passage, and a bleed-off valveprovided in the discharge flow passage. The control deviceis configured in such a manner that when a manipulate signal for extending the boom cylinderis input from the control lever, the bleed-off valveis closed, the selector valveis subsequently opened, and the open circuit pumpis controlled.

Hydraulic driving system

There is provided a driving device for a work machine, having a closed hydraulic circuit system for driving cylinders with hydraulic pumps, the driving device making the speed of operation substantially the same in both directions of piston rod extension and contraction. The driving device includes: a first hydraulic pump that has flow rate control device for controlling the flow rate and direction of hydraulic fluid to be delivered; a single rod hydraulic cylinder that is driven with the hydraulic fluid to drive one of work members of a work device on the work machine; a closed hydraulic circuit that connects the first hydraulic pump with the single rod hydraulic cylinder to form a closed circuit using flow lines through which the hydraulic fluid flows; a branch line that branches from the flow line between the first hydraulic pump and the single rod hydraulic cylinder; a first flow line of which one end is connected to the branch line; a tank to which the other end of the first flow line is connected; and a hydraulic fluid flow rate control device attached to the first flow line to control the flow rate of the hydraulic fluid flowing from the branch line to the tank or from the tank to the branch line.

Driving device for work machine and work machine equipped therewith

To provide a driving device capable of improving the operability of a plurality of single rod hydraulic cylinders. The present invention takes a construction provided with a closed circuit A in which first and third hydraulic pumpsand a boom cylinderare connected through selector valvesin a closed-circuit fashion, a plurality of open circuits E, F provided with second and fourth hydraulic pumpsand selector valvesthat switch the supply destinations of hydraulic oils flowing out from the second and fourth hydraulic pumps, and a connection passageconnected to sides of the selector valvesfrom which sides hydraulic oil flows out, and connected to the closed circuit A.

Driving device for work machine

A load detecting device that can highly accurately detect the magnitude and direction of a load whose direction of action changes regardless of the dimension of a pin is provided. Also, a working machine that is provided with this load detecting device and allows work to be performed safely and highly efficiently is provided. The load detecting device is configured with a pin-type load celland a load calculating unit. The pin-type load cellis provided with three pairs of or three strain detecting units that are placed in the circumferential direction of the pin body. The load calculating unitselects, from among the three or more pairs of or three or more strain detecting units, two pairs of or two strain detecting units that are less influenced by a change in the cross-sectional shape of the pin body, and calculates a load that acts on the pin bodyaccording to an output of these selected strain detecting units.

Load detecting device and working machine provided with same

A basic information calculator device calculates basic information for area limiting excavation control to control a construction machinery work device so that the construction machinery does not perform excavation beyond a target excavation surface. The basic information calculator includes: a storage device having stored therein three-dimensional information of the target excavation surface; a two-dimensional information extractor for obtaining the intersecting line between a reference surface that is the target excavation surface and the operational plane of the work device based on the three-dimensional information and the current positional information of the construction machinery to extract a reference line that is the intersecting line as the two-dimensional information of the reference surface in the operational plane; and a characteristic point transmitter for transmitting the Z-coordinates of characteristic points on the reference line to an area limiting excavation controller as the basic information.

Device and method for calculating basic information for area limiting excavation control, and construction machinery

A dual-arm work machine includes: a first front working machine to which a first attachment is mounted; a second working machine to which a second attachment is mounted; a first drive device that drives the first front working machine and the first attachment based on a first drive command from a first operation member; a second drive device that drives the second front working machine and the second attachment based on a second drive command from a second operation member; and a drive command output device that inputs the first and second drive commands, and generates and outputs a shared drive command that drives the first and second drive devices.

Dual-arm work machine

To provide a work machine with high stability in which a dynamic balance can be evaluated easily while the influence of a sudden stop of an travel base, an upperstructure and a work front is taken into consideration. A stabilization control calculation unit () and a command value generating unit () are provided in a control device () of the work machine. The stabilization control calculation unit () uses a sudden stop model and position information of each movable portion of the travel base and a machine body including the work front () to predict a change of stability until reaching a complete stop when a control lever () in an operating state is instantaneously brought back to a stop command position, and calculates a motion limit needed to prevent destabilization from occurring at any time instant until reaching the stop. The command value generating unit () corrects the command information to a drive actuator on the basis of the calculation result of the stabilization control calculation unit ().

Disclosed is a working machine that computes and displays moment by moment its dynamic stability and its state of contact with a ground in view of an inertia force and an external force applied to the working machine. Specifically, a working machine is provided with an undercarriage, a working machine main body mounted on the undercarriage, a front working mechanism attached pivotally in an up-and-down direction to the working machine main body, and a working attachment connected to a free end of the front working mechanism. The working machine includes a ZMP computing means for calculating coordinates of a ZMP by using position information, acceleration information and external force information on respective movable portions of the main body, which includes the front working mechanism, and undercarriage, and a stability computing means for calculating a support polygon formed by plural ground points of the working machine with a ground, and, when the ZMP is included in a warning region formed inside a perimeter of the support polygon, producing a tipping warning sound. The ZMP and the support polygon, which includes the warning region, is computed, and a display or warning is produced.

Operation machine

Disclosed is a safety system for a working machine, which allows an operator to instantaneously, readily and precisely recognize current stability during work including operations of a front working mechanism and swing operations. In a safety system for a working machine, a controller is provided with a ZMP calculating means () for calculating coordinates of a ZMP by using position information, acceleration information and external force information on respective movable portions of a main body, which includes a front working mechanism, and undercarriage, and a stability computing means () for calculating a support polygon formed by plural ground contact points of the working machine with a ground, and, when the ZMP is included in a warning region formed inside a perimeter of the support polygon, producing a tipping warning; the safety system is provided with a display () for displaying a top plan view of the working machine and a ZMP position of the working machine relative to the support polygon; the ZMP calculating means and stability computing means compute and display the ZMP position and the support polygon including the warning region therein; and the safety system produces a tipping warning when the calculated ZMP position is included in the warning region formed inside the perimeter of the support polygon.

Work machine safety device

A dual arm hydraulic excavatorhas two front work devices A and B, provided on left and right sides of a front portion of an upper swing structureand swingable in a top-bottom direction of excavator. Front work devices A and B have arms, boomsand working devices. An average of angle &#x3b8;a of the armrelative to the boomand angle &#x3b8;b of the armrelative to the boomis defined as an average arm angle &#x3b8;c. A range of the average arm angle, in which the average arm angle &#x3b8;c is larger than a predetermined threshold value &#x3b8;c, is defined as an unstable range N. A range of the average arm angle, from an inner side of the unstable range and adjacent to the unstable range, is defined as a stable state limit range M.

Growing community of inventors

Ushiku, Japan

Akinori Ishii