Hitachi Construction Machinery Co., Ltd.

Shuuichi Meguriya

Shiho Izumi

Hiroki Takeuchi

Kouji Ishikawa

Teruki Igarashi

Tarou Akita

Ryu Narikawa

Yasuhiko Kanari

Ryuu Narikawa

Akihiro Narazaki

Akinori Ishii

Eiji Egawa

Takahiko Kurose

A work machine includes a work device having a boom, an arm, and work equipment and a controller that sets a target surface, and calculates a work equipment-to-target surface distance on the basis of signals from a position sensor and a posture sensor, and carries out control to decelerate the arm to keep the work equipment from excavating ground beyond the target surface when the work equipment-target surface distance has become shorter than a predetermined distance. The controller determines whether there is a possibility that the work equipment enters the target surface when operation of the arm is carried out based on the set target surface and the position sensor and posture sensor signals, and does not carry out the deceleration control when the work equipment-to-target surface distance is shorter than the predetermined distance and it is determined there is no possibility that the work equipment enters the target surface.

Work machine

A work machine includes a swing structure, a work device, a position sensor, a posture sensor and a controller that performs machine control on the basis of a target surface set on the basis of target shape data, the position information of the swing structure, and the information about the posture of the work machine. When the controller becomes unable to obtain the position information of the swing structure, the controller stores swing angle information of the swing structure, the swing angle information being sensed by the posture sensor at that time. The controller prohibits execution of the machine control when the swing structure is positioned outside a swing range; and permits the execution of the machine control when the swing structure is positioned inside the swing range and when the swing structure is positioned inside the swing range again after being positioned outside the swing range.

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.

A controllermounted on a hydraulic excavatorthat is able to perform machine control transmits work situation parameters (machine body position, hydraulic working fluid temperature, bucket weight, and target surface gradient) to a management server, receives, from the management server, control command correction values that are calculated by the management server on the basis of the work situation parameters and that represent correction values for correcting control commands, and controls hydraulic actuators, andwith corrected control commands that represent the control commands corrected on the basis of the control command correction values.

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 work machine () having a controller () that can perform area limiting control, the work machine further includes a machine control ON/OFF switch () that alternatively selects an ON position permitting execution of the area limiting control and an OFF position prohibiting execution of the area limiting control. The controller () has an engine control section () that performs automatic idling control when a predetermined period of time (T1) has elapsed after a point in time when all of operation levers () have attained a neutral state. The engine control section () is configured to execute the automatic idling control during when the switch () is in the OFF position and not to execute the automatic idling control during when the switch () is in the ON position.

Hydraulic excavator with area limiting control function

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 work machine has a controller which has an area limiting control section correcting the pilot pressures of pilot lines, a regeneration control section adjusting the flow rate of the hydraulic fluid caused to flow from a tank side line of an arm cylinder into a pump side line thereof between zero and a predetermined upper limit value, and a regeneration control switching section that issues an order to the regeneration control section to set the predetermined upper limit value to a first set value when the function of the area limiting control section is invalid and that issues an order to the regeneration control section to set the predetermined upper limit value to a second set value that is smaller than the first set value when the function of the area limiting control section is effective.

An area limiting excavation control system for construction machines including a control unit () that performs area limiting control by controlling at least one of a plurality of hydraulic cylinders () on the basis of a posture and a position of each of a boom (), an arm (), and a bucket (). The control system includes an angle sensor group () that detects rotational angles of the boom (), the arm (), and the bucket (), and a tilting angle sensor group () that detects ground angles of the boom (), the arm (), and the bucket (). The control unit () selects, from among the angle sensor group () and the tilting angle sensor group (), a sensor to be used for calculating a posture and a position of each of the boom (), the arm (), and the bucket () in accordance with a magnitude of speed of at least one of the boom (), the arm (), and the bucket ().

Area limiting excavation control system for construction machines

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.

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Ishioka, Japan

Shuuichi Meguriya