Hitachi Construction Machinery Co., Ltd.

Takaaki Chiba

Shinya Imura

Yasutaka Tsuruga

Kento Kumagai

Hidekazu Moriki

Shinji Nishikawa

Akihiro Narazaki

Hiroaki Amano

Genroku Sugiyama

Shinjiro Yamamoto

Akira Kanazawa

Hiroshi Sakamoto

Hiroyuki Yamada

Hiroaki Tanaka

Hisami Nakano

Katsuaki Kodaka

Yuho Saito

Shinjirou Yamamoto

Shiho Izumi

Manabu Edamura

Yusuke Suzuki

Masamichi Ito

Yuusuke Suzuki

Koji Shiwaku

Yusuke Imai

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.

Work machine

An overhead-view image of a work site is presented to an operator of a work machine even when the number of imaging devices at a construction site is lacking. The present disclosure provides an information presentation device for generating and outputting a terrain image relating to a construction site. The information presentation device includes a storage device that stores a program for performing a predetermined imaging process on the terrain image, and a processor for reading the program from the storage device and generating the terrain image. The processor performs: a process of using an image of the construction site acquired by at least one imaging device installed at a construction site, to acquire a first overhead-view image representing a current terrain of the construction site as viewed from above; a process of acquiring a second overhead-view image acquired by a method other than capturing by the imaging device installed at the construction site, and representing an original terrain of the construction site as viewed from above; and an image synthesis process of superimposing the first overhead-view image and the second overhead-view image to generate a first synthesized overhead-view image.

Information presentation device

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.

There is provided a work machine which can improve accuracy of control of an actuator when a pressure difference between a hydraulic pump and the actuator is large and the demanded flow rate of the actuator is small. An auxiliary flow rate controller is configured such that an opening area of a main valve changes between a maximum opening area and zero according to the opening area of a pilot variable restrictor when the opening area of the pilot variable restrictor is equal to or more than a predetermined opening area and that the opening area of the main valve is zero irrespective of the opening area of the pilot variable restrictor when the opening area of the pilot variable restrictor is less than the predetermined opening area.

To provide a work machine that enables enhancement of shaping accuracy near a boundary line between two adjacent target surfaces. A controllerextracts, from among a plurality of target surfaces, a second target surface Sthat is a target surface adjacent to a first target surface S, calculates a boundary line Lbetween the first target surface Sand the second target surface S, and, prior to a work toolpassing the first boundary line L, corrects a control signal for a posture control actuatorsuch that the angular difference Ebetween a reference line Lset on the work tooland the boundary line Lbecomes small.

A type of an object is determined and the movement direction of the object is predicted on the basis of a sensing result of the object sensed by an on-machine obstacle sensor. Information relating to the object that is the object sensed by the on-machine obstacle sensor and has been determined to have moved to the outside of a sensing range of the on-machine obstacle sensor is immediately deleted from an environment map on the basis of the type and the movement direction of the object. This can properly process information on the object that has gotten out of the sensing range, according to the cause of the object getting out of the sensing range.

A hydraulic excavatorincludes an engine, a main hydraulic pumpdriven by the engine, a plurality of hydraulic actuators driven with pressure oil discharged from the main hydraulic pump, a plurality of flow rate control valves adapted to control the flow rate of pressure oil to be supplied from the main hydraulic pumpto the respective hydraulic actuators, a pilot hydraulic pumpadapted to supply pressure oil for driving the flow rate control valves, and a controllerconfigured to control the discharge flow rate of the pilot hydraulic pump. The controllercontrols the discharge flow rate of the pilot hydraulic pumpsuch that it becomes equal to the sum of requested pilot flow rates determined in accordance with control commands for the respective flow rate control valves and a preset standby flow rate.

An operation assistance system for a work machine includes an operation assistance function and a work assistance function. Both of the operation assistance function and the work assistance function are switchable between enabled and disabled states. When the work assistance function is in an enabled state and when the work area is set outside of the stop area to surround the stop area, the operation assistance system sets the work area as the stop area such that the stop area is extended and overlaid on the work area, and automatically enables the operation assistance function when the operation assistance function is in a disabled state.

Operation assistance system for work machine having an extendable work area

A work machine includes a controller that executes a semi-automatic control to correct an operation amount indicated by an instruction given by operation devices. The controller is configured to make a compaction determination to determine whether or not a bottom surface of a bucket is being pressed against a ground; and to further correct an operation amount having been corrected by the semi-automatic control, such that a force that the bucket applies to the ground increases if the bottom surface of the bucket is determined as being pressed against the ground.

Compaction control of work machine

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.

A construction machine is provided that can cause each hydraulic actuator to accurately operate according to operation by an operator in combined operation in which a hydraulic fluid of a hydraulic pump is subjected to flow dividing and is supplied to plural hydraulic actuators. A controller, in a case of determining that combined operation is being carried out, controls a regulatorin such a manner that the delivery flow rate of a hydraulic pumpbecomes larger than the total target flow rate of plural hydraulic actuators, and, and controls the respective opening amounts of plural directional control valves, andin such a manner that the difference between the respective target flow rates of the plural hydraulic actuators and the respective inflow flow rates of the plural hydraulic actuators sensed by velocity sensorstobecomes small.

Construction machine

The hydraulic excavatorincludes a work implement, a detection device that detects an obstacle around the hydraulic excavator, and a controllerthat controls the operation of the work implement. The controllerhas a driving assistance function and a work assistance function. The work assistance function is switchable between enabled and disabled. When the work assistance function is switched to enabled, the controllersuppresses, for an obstacle detected in a monitoring range but outside of a work range, the driving assistance function in comparison with when the work assistance function is switched to disabled.

Work machinery

An hydraulic excavator calculates an estimated excavation volume Va defined by a bucket claw tip position (first position) at an excavation start, a bucket claw tip position (second position) at an excavation end set in advance, a current landform, a first target surface, and a bucket width w. A second target surface is generated at a position superior to the first target surface when the estimated excavation volume Va exceeds a limit volume Vb; and the second target surface is generated at a position at which the excavation volume defined by the first position, the second position, the current landform, the second target surface, and the bucket width is closer to the limit volume Vb. The hydraulic actuators are controlled such that an operating range of a work implement is limited on the second target surface and to an area superior to the second target surface.

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Kasumigaura, Japan

Takaaki Chiba