Work machine

Patent metadata

Field	Value
Publication number	US-12371874-B2
Application number	US-202118022812-A
Country	US
Kind code	B2
Filing date	Nov 12, 2021
Priority date	Dec 7, 2020
Publication date	Jul 29, 2025
Grant date	Jul 29, 2025

Abstract

A working status indicating a status related to the present work of a hydraulic excavator 1 is determined on the basis of operation signals output from a control lever 24 , posture information output from inertial measuring devices 27 to 30 , load information output from pressure sensors 32 and 33 , and a work area set by a display input device 26 , an operation form indicating contents of an operation in operation correction control of a front work implement 12 is decided from a plurality of operation forms set in advance, according to the determined working status, and the operation correction control is performed such that the front work implement moves according to the operation form. Thus, an appropriate assisting operation can be performed in machine control, so that the work accuracy can be improved.

First claim

The invention claimed is:

1. A work machine comprising:
a lower track structure;
an upper swing structure that is swingable with respect to the lower track structure;
an articulated front work implement that is attached to the upper swing structure and includes a plurality of front implement members rotatably coupled together;
an operation device that outputs operation signals for operating the upper swing structure and the front work implement according to amounts of operations made by an operator;
a plurality of front work implement actuators that individually drive the plurality of front implement members on a basis of driving signals generated according to the operation signals output from the operation device;
a swing actuator that swing-drives the upper swing structure on a basis of the operation signal output from the operation device;
a posture information sensor that senses posture information as information regarding postures of the upper swing structure and the front work implement; and
a controller that performs operation correction control to output a driving signal to at least one of the plurality of front work implement actuators such that the front work implement is set in a predetermined position or posture on a predetermined target surface and within one area with respect to the target surface, on a basis of the operation signals output from the operation device and the posture information sensed by the posture information sensor,
the work machine further including a load information sensor that senses load information as information regarding a load on at least one of the plurality of front work implement actuators, and
a display input device that displays information and receives an instruction from the operator,
the controller is configured to:
set a work area over the target surface based on the instruction from the operator inputted to the display input device,
determine a working status indicating a status related to present work of the work machine, on a basis of the operation signals output from the operation device, the posture information sensed by the posture information sensor, the load information sensed by the load information sensor, and the work area set by the controller based on the instruction,
decide an operation form indicating contents of an operation in the operation correction control of the front work implement, from a plurality of operation forms set in advance, according to the determined working status, and
perform the operation correction control such that the front work implement moves according to the operation form.

2. The work machine according to claim 1 , wherein
the controller is configured to determine the working status on a basis of a work type and a work tool state, the work type being a classification that indicates a state of work performed by the work machine and being set on a basis of a position, an operation direction, and the work area of the front work implement, the work tool state being a classification that indicates a state of a work tool that is one of the plurality of front implement members provided to a distal end of the front work implement and being set on a basis of a posture of the work tool with respect to the target surface and a load on the front work implement.

3. The work machine according to claim 2 , wherein
the controller is configured to:
define in advance, as the work type, extra-target work that indicates a state in which the front work implement operates outside the work area, target approaching work that indicates a state in which the front work implement moves from an outside of the work area to an inside of the work area and approaches the target surface, target vicinity work that indicates a state in which the front work implement operates within the work area, and target leaving work that indicates a state in which the front work implement separates from the target surface and moves from the inside of the work area to the outside of the work area, and
determine the work type on a basis of a positional relation between the front work implement and the target surface, the operation direction of the front work implement with respect to the target surface, and the work area.

4. The work machine according to claim 2 , wherein
the front work implement includes the work tool that is one of the plurality of front implement members provided to the distal end of the front work implement and that is capable of being filled with soil, and
the controller is configured to:
define in advance, as the work tool state, a work tool soil filled state that indicates whether or not soil is present within the work tool and a work tool posture state that indicates whether or not an angle of the work tool with respect to the target surface is within a range of a predetermined relative angle, and
determine the work tool state on the basis of the posture of the work tool with respect to the target surface and the load on the front work implement.

5. The work machine according to claim 1 , wherein
the front work implement includes a work tool that is one of the plurality of front implement members provided to a distal end of the front work implement and that is capable of being filled with soil, and
the controller is configured to:
define in advance, as a mode of the operation form, a posture maintaining mode in which a posture of the work tool with respect to the target surface is maintained to be a present posture, a horizontal maintaining mode in which the posture of the work tool with respect to the target surface is maintained to be horizontal, and a position designating mode in which a position of the work tool is made to coincide with the target surface, and
perform the operation correction control such that the front work implement moves according to the operation form.

Assignees

• Hitachi Construction Mach Co

Inventors

• Nakamura Satoshi
• SHIWAKU Kouji
• Imura Shinya

Classifications

• E02F9/262 Primary

  with follow-up actions to control the work tool, e.g. controller · CPC title

• E02F9/2296

  Systems with a variable displacement pump · CPC title

• E02F9/2292

  Systems with two or more pumps · CPC title

• E02F9/2285

  Pilot-operated systems · CPC title

• E02F9/2203

  Arrangements for controlling the attitude of actuators, e.g. speed, floating function · CPC title