Hitachi Construction Machinery Co., Ltd.

Akihiro Narazaki

Shinji Nishikawa

Kento Kumagai

Hiroaki Amano

Shinya Imura

Yasutaka Tsuruga

Takaaki Chiba

Teruki Igarashi

Hiroaki Tanaka

Yusuke Suzuki

Genroku Sugiyama

Hiroshi Sakamoto

Katsuaki Kodaka

Hisami Nakano

Nobuei Ariga

Shinjiro Yamamoto

Kouji Ishikawa

Yasuhiko Kanari

Shuuichi Meguriya

Masamichi Ito

Shinjirou Yamamoto

Hidetoshi Satake

Kazunori Nakamura

Tsuyoshi Nakamura

Hideo Karasawa

Kazuhiko Mizoguchi

Yasuo Okano

Naoki Hagiwara

Tomoaki Kaneta

Takahiro Kobayashi

Tarou Akita

Keiichirou Anahara

Masatoshi Morikawa

Yoshihiro Shirakawa

Masamichi Itou

Daiki Itou

Ryota Kameoka

Shu Shirato

Masamichi Itoh

When a bucketis grounded on soil, an operation signal is outputted or corrected such that a relative angle of the bucketwith respect to a target surface is maintained if a distance D between the bucketand the target surfaceis equal to or less than a preset first threshold value D. When the bucketis not grounded on soil, the operation signal is outputted or corrected such that the relative angle of the bucketwith respect to the target surfaceis maintained if the distance between the bucketand the target surfaceis equal to or less than a preset second threshold value Dset smaller than the first threshold value D. As a result, control to maintain an angle of a work tool can be suitably started.

Work machine assisting operation of operator by performing semi-automatic control

A controller of a work machine computes a target velocity of a fluid pressure actuator according to an operation signal from an operation device, computes target thrust or target torque of the fluid pressure actuator on the basis of a driven state of the fluid pressure actuator, and controls a velocity of the fluid pressure actuator by a meter-out control valve on the basis of the operation signal from the operation device and controls at least one of a pump and a meter-in control valve such that a pressure on a meter-in side of the fluid pressure actuator is equal to or higher than a predetermined value when a positive or negative sign of the target velocity as a computation result is different from a positive or negative sign of the target thrust or the target torque as a computation result.

Work machine

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.

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.

A work machine includes a work implement provided to a machine body, a posture sensor that senses posture information regarding the work implement, a controller configured to compute a specific position of the work implement on the basis of the posture information, set a limited area that the work implement is prohibited from entering, compute a movable distance as a distance between the limited area and the specific position of the work implement, and limit operation of the work implement according to the movable distance to prevent the work implement from entering the limited area, and an input device for inputting to the controller input information input by an operation of an operator. The controller includes a storage device that stores boundary information related to a plurality of different kinds of shapes of limited area boundaries, and the controller is configured to select one from among the plurality of kinds of shapes of limited area boundaries included in the boundary information, on the basis of the input information input from the input device, and set a limited area boundary of the selected kind of shape.

The invention of the present application intends to provide a work machine that can improve the work performance by keeping the work state of work equipment conforming to the intention of an operator in machine control for causing the work equipment to follow an excavation target surface. For this purpose, a controller determines the work state of the work equipment on the basis of an operation input amount inputted from an operation input device and the posture of the work equipment with respect to the target surface, computes a range of an action command value of actuators in which the work state determined is kept, and corrects, within the range, the action command value of the actuators to make the distance between the work equipment and the target surface small.

An object of the present invention is to provide a work machine that can increase the operation speed of an actuator by a regenerating function while ensuring accuracy of position control of the actuator. For this purpose, a controller computes a target actuator supply flow rate by subtracting a regeneration flow rate from a target actuator flow rate, computes a target flow control valve opening amount on the basis of the target actuator supply flow rate, computes a target pump flow rate equal to or more than the sum of a plurality of the target actuator supply flow rates, controls flow control valves according to the target flow control valve opening amount, and controls a hydraulic pump according to the target pump flow rate.

The present invention intends to provide a work machine that can execute speed control of an actuator and torque control of a swing motor by a simple configuration at the time of combined operation to simultaneously drive the swing motor and the other actuator. For this purpose, a controller calculates a pump target flow rate on the basis of an actuator target flow rate and a swing target flow rate and calculates a target meter-in opening area of an actuator directional control valve on the basis of the actuator target flow rate, a pump pressure, and an actuator meter-in pressure. The controller calculates target torque of the swing motor on the basis of the input amount of operation devices and output values of posture sensors and calculates a swing target meter-out pressure on the basis of the target torque and a swing meter-in pressure. The controller calculates a target meter-out opening area of a swing directional control valve on the basis of the swing target meter-out pressure and a swing meter-out pressure.

An object of the present invention is to provide a work machine that makes it possible to perform, with a simple configuration, speed control of respective actuators and thrust control of a particular actuator that regenerates the flow of a return fluid, at the time of combined operation to simultaneously drive the particular actuator and another actuator. For this purpose, a controller calculates a target thrust that is a target value of a thrust of the particular actuator on the basis of an input amount of an operation device and an output value of a posture sensor, calculates a target meter-out pressure that is a target value of a meter-out pressure of the particular actuator on the basis of the target thrust and a meter-in pressure of the particular actuator, and calculates a regeneration control valve target opening area that is a target value of an opening area of a regeneration control valve on the basis of the target meter-out pressure and the meter-out pressure of the particular actuator.

The invention of the present application has as its object the provision of a work machine that is equipped with a function to prevent a work device thereof from going into an entry prohibited area and can satisfy both working precision and working efficiency of the work device. A controller is therefore configured to start work range limiting control to decelerate or stop an action of a machine main body or the work device when a distance between a monitor point set beforehand on the work device and the entry prohibited area decreases to a first distance, to end the work range limiting control when the distance between the monitor point and the entry prohibited area increases to a second distance greater than the first distance, and to change the second distance according to an operation amount of an operation device.

Both a control for limiting operation of a machine body and a control for raising engine speed are achieved when an obstacle is detected. To this end, a machine controller performs operation limiting control by conducting a control for reducing the speed of the engine when the machine body does not require engine speed increase control and an obstacle is sensed by obstacle sensors, and the machine controller performs supply flow rate reduction control for reducing the flow rates of the hydraulic fluid supplied to hydraulic actuators from a hydraulic pump when the machine body requires the engine speed increase control and an obstacle is sensed by the obstacle sensors.

Construction machine

A hydraulic actuator includes a control valve unit that controls a flow of a hydraulic fluid supplied from a hydraulic pump to a plurality of hydraulic actuators, a plurality of control lever devices that output a pilot pressure actuating the control valve unit, with use of a discharged pressure from a pilot pump as a source pressure, a solenoid valve unit including a plurality of solenoid pressure reducing valves connected between the plurality of control lever devices and the control valve unit, and a controller configured to calculate velocity limits for the plurality of hydraulic actuators on the basis of signals from a plurality of posture sensors and control openings of the solenoid pressure reducing valves, in which the controller is configured to control the openings of the solenoid pressure reducing valves for arm crowding and arm dumping to be larger than an opening based on the velocity limits while a boom raising operation signal is being output from the control lever devices.

Hydraulic excavator

When an operation amount of an operation lever corresponding to a boom cylinder is equal to or smaller than an operation amount of an operation lever corresponding to an arm cylinder, an estimated velocity of the arm cylinder used for region limiting control is computed on the basis of a first condition defining, in advance, a relation between the operation amount of the operation lever and the estimated velocity of the arm cylinder. When the operation amount of the operation lever corresponding to the boom cylinder is larger than the operation amount of the operation lever corresponding to the arm cylinder, the estimated velocity of the arm cylinder used for the region limiting control is computed as a velocity higher than the estimated velocity of the arm cylinder computed on the basis of the first condition. The behavior of the work device can thereby be stabilized.

A main controller generates a supplemented design face that passes through a junction or above the junction between a first design face and a second design face adjacent to each other, among a plurality of design faces, the supplemented design face having one end thereof positioned on the first design face and another end thereof positioned on the second design face, sets a curvature 1/R of the supplemented design face according to an arm operation amount of an operation lever device, and executes semi-automatic excavation control to control a boom cylinder with one of the faces included in the supplemented design face being set as the target face.

Provided is a construction machine that avoids automatic release of operation restriction involving, for example, sudden acceleration unintended by an operator even when an inclined angle of a vehicle body changes. The construction machine includes a vehicle bodyconfigured to operate, 3D sensors (obstacle detection devices), andthat detect an obstacle present around the vehicle body, an inclined angle determination device (an inclined angle detection device)that detects the inclined angle of the vehicle body, and a vehicle body controller (a controller)having an operation restriction function that performs a restriction control to restrict an operation of the vehicle bodywhen the 3D sensors (the obstacle detection devices), anddetect an obstacle. When the inclined angle of the vehicle bodyexceeds a predetermined threshold while the restriction control is not performed with the operation restriction function, the vehicle body controller (the controller)disables the operation restriction function. When the inclined angle of the vehicle bodyexceeds the predetermined threshold while the restriction control is performed with the operation restriction function, the vehicle body controller (the controller)does not disable the operation restriction function.

Growing community of inventors

Tsuchiura, Japan

Akihiro Narazaki