Hitachi Construction Machinery Co., Ltd.

Shinji Nishikawa

Shinya Imura

Kouji Ishikawa

Hiroaki Amano

Hidetoshi Satake

Akihiro Narazaki

Takatoshi Ooki

Kento Kumagai

Shiho Izumi

Yasutaka Tsuruga

Takaaki Chiba

Manabu Edamura

Masafumi Hita

Tomoaki Kaneta

Genroku Sugiyama

Shinji Ishihara

Shinjiro Yamamoto

Masatoshi Morikawa

Seiji Hijikata

Hiroaki Tanaka

Kouichi Shibata

Takenori Hiroki

Shinjirou Yamamoto

Ryouhei Yamashita

Masatoshi Hoshino

Hidekazu Moriki

Katsuaki Kodaka

Kazuhiko Mizoguchi

Naoki Hagiwara

Keiichiro Nakamura

Toshihiko Ishida

Manabu Sugiura

Keiichirou Anahara

Taiki Aizawa

Ryousuke Itou

Satoshi Iwasaki

Ryota Kameoka

Shingo Sawada

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 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.

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 is capable of flexibly setting an entry-prohibited area for a work device according to an operator's intention. To achieve this, a controllersets, as a first position, the position of a work toolthat is located when a setting switchis operated, and sets, as a second position, the position of the work toolthat is located when the setting switchis operated after the setting of the first position. Further, the controllersets, as a boundary surface of an entry-prohibited area, a planethat passes through a first reference point A and a second reference point B and that is perpendicular to a ground contact surface of a lower track structure. The first reference point A is one of a plurality of reference pointsL andR on the work toollocated at the first position, the plurality of reference pointsL andR being preset on the work tool. The second reference point B is one of the plurality of reference pointsL andR on the work toollocated at the second position.

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.

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

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.

A work machine that can keep the control accuracy of actuators irrespective of temperature variation of a hydraulic operating fluid that passes through flow rate controllers that control the flow rates of supply to the actuators is provided. For this purpose, the flow rate controllers each have a valve body that is disposed on a main hydraulic line connecting a delivery line of a hydraulic pump and the actuator and that moves according to an operation pressure from a solenoid proportional pressure reducing valve, a sampling hydraulic line that branches from the main hydraulic line, and a temperature sensor set on the sampling hydraulic line. The controller is configured to correct a command electrical signal to the solenoid proportional pressure reducing valve according to a signal from the temperature sensor.

The invention of the present application intends to provide a work machine that can ensure high operability by preventing abrupt actuation of an actuator and a shock to a machine body by use of a bleed-off function at the time of starting of the actuator and that can improve the energy-saving performance by reducing a bleed-off flow rate after the starting of the actuator. For this purpose, a controller opens a bleed-off valve at a timing at which an operation device is being operated and before a flow rate of a hydraulic pump starts increasing, and closes the bleed-off valve at a timing at which the operation device is being operated and after the flow rate of the hydraulic pump has started increasing.

In a hydraulic excavator including a machine body and a front work device, when an object is detected by sensors for detecting an object around the machine body when operation limiting control for limiting the operation of at least one of the machine body and the front work device is enabled, or when an operation device is operated, the detection of the object is notified to an operator by a first state warning, and when the operation limiting control is enabled and when the operation device is not operated, the detection of the object is notified to the operator by a second state warning that is weaker in warning intensity than the first state warning. Accordingly, the botheration for the operator can be suppressed while securing the effectiveness of an alarm in periphery monitoring, and the safety performance can be enhanced.

Work machine and periphery monitoring system

Provided is a construction machine which can promptly adjust the rotational speed of a swing motor to a target rotational speed. A controller calculates a target rotational speed of the swing motor based on input from an operation device, calculates a degree of deviation of a rotational speed detected by a rotational speed sensor from the target rotational speed, sets a target driving pressure of the swing motor according to a moment of inertia about a swing axis of a swing structure and a work device and controls a pressure adjusting device in such a manner as to reduce a difference between a driving pressure detected by a pressure sensor and the target driving pressure, when the degree of deviation is larger than a predetermined value, and controls the pressure adjusting device in such a manner as to reduce a difference between the rotational speed detected by the rotational speed sensor and the target rotational speed, when the degree of deviation is equal to or smaller than the predetermined value.

Provided is a work machine which can increase the operation speed of an actuator by a regeneration function while securing the position control accuracy of the actuator. A controller is configured to calculate a regeneration flow rate on the basis of an input amount of an operation lever and a target actuator flow rate, subtract the regeneration flow rate from the target actuator flow rate to calculate a target actuator supply flow rate, calculate a target flow rate control valve opening amount on the basis of the target actuator supply flow rate, calculate a target pump flow rate that is equal to or higher than a total target actuator supply flow rate, control a selector valve on the basis of the input amount of the operation lever, control a flow rate control valve according to the target flow rate control valve opening amount, and control a hydraulic pump according to the target pump flow rate.

There is provided a construction machine that draws attention from the surroundings of the machine body when the prime mover is started and that can have the operator reliably confirm the surroundings of the machine body before the prime mover is started. An engine start control sectionof a main controllerinhibits an enginefrom starting when a key switchis operated while a horn switchis not operated, inhibits the enginefrom starting when the key switchis operated for the duration until a first set time Telapses after the operation of the horn switchhas been finished, permits the engineto start in a case the key switchis operated for the duration until a second set time Telapses after the first set time Thas elapsed, and inhibits the engineagain from starting when the key switchis operated if the engineis not started for the duration until the second set time Telapses.

Provided is a work machine which can achieve both of excellent operability when an operator manually operates a machine body or a work device and an accuracy of control of the machine body or the work device when a controller performs automatic control. The controller is configured to, in a case where the automatic control function selector switch gives an instruction to disable the automatic control function, adjust an opening amount of a bleed-off valve to a maximum opening amount or an opening amount corresponding to input amounts of control levers, and in a case where the automatic control function selector switch gives the instruction to enable the automatic control function, adjust the opening amount of the bleed-off valve, in at least part of an operation region of the control levers, so as to be smaller than the opening amount with the instruction to disable the automatic control function being given.

Growing community of inventors

Kasumigaura, Japan

Shinji Nishikawa