Work machine

Patent metadata

Field	Value
Publication number	US-11168459-B2
Application number	US-201716344367-A
Country	US
Kind code	B2
Filing date	Nov 8, 2017
Priority date	Mar 15, 2017
Publication date	Nov 9, 2021
Grant date	Nov 9, 2021

Abstract

Provided is a hydraulic excavator (1) that performs work by operating an arm (9) after moving a bucket (10) to a work start position. An operation determination section (81c) determines, based on an operation performed on an operation device, whether a front work device (1A) is engaged in a work preparation operation for moving the bucket to the work start position. When the operation determination section determines that the front work device is engaged in the work preparation operation at the time of operation of the operation device, an actuator control section (81) controls a bucket cylinder (7) such that the angle of a work tool with respect to a target surface coincides with a preset target angle (θTGT).

First claim

The invention claimed is:

1. A work machine that performs work by operating an arm after moving a work tool to a work start position, the work machine comprising:
a work device that includes a boom, the arm, and the bucket;
a plurality of hydraulic actuators that drive the work device;
an operation device that instructs the work device to operate in accordance with an operator's operation;
a target surface setting device that sets a target surface indicative of a target shape of a work target for the work device;
a target angle setting device that sets a target angle of the bucket; and
a control device configured to:
perform bucket angle control as machine control to control a hydraulic actuator related to the bucket among the plurality of hydraulic actuators such that an angle of the bucket coincides with the target angle, and
perform boom raising control as the machine control to control a hydraulic actuator related to the boom rising operation among the plurality of hydraulic actuators, based on a position of the target surface, a posture of the work device, and an operation amount of the operation device, such that a claw tip of the bucket is positioned on or above the target surface, wherein

the control device further configured to:
determine, based on the operation performed on the operation device, whether the work device is engaged in a work preparation operation for moving the bucket to the work start position,
when it is determined that the work device is engaged in the work preparation operation at the time of operation of the operation device, perform the bucket angle control and the boom raising control as the machine control, and
when it is determined that the work device is not engaged in the work preparation operation at the time of operation of the operation device, perform the boom raising control as the machine control without performing the bucket angle control.

2. The work machine according to claim 1 , wherein
the control device further configured to perform the bucket angle control when the work device is determined to be engaged in the work preparation operation at the time of operation of the operation device and a distance between the target surface and the bucket is equal to or smaller than a predetermined value.

3. The work machine according to claim 1 , wherein
when a pivot speed of the arm is equal to or lower than a predetermined value or a component of a speed vector of the arm or of the bucket, the component being vertical to the target surface, is oriented toward the target surface, the control device determines that the work device is engaged in the work preparation operation.

4. The work machine according to claim 1 , further comprising:
a control selection device that selectively enables or disables the machine control to be provided by the actuator control section.

5. The work machine according to claim 1 , wherein
the actuator control section executes the machine control such that the angle of the work tool with respect to the target surface coincides with the target angle at a desired position referenced to the target surface.

6. A work machine that performs work by operating an arm after moving a work tool to a work start position, the work machine comprising:
a work device that includes a boom, the arm, and the work tool;
a plurality of hydraulic actuators that drive the work device;
an operation device that instructs the work device to operate in accordance with an operator's operation; and
a control device that includes an actuator control section for controlling at least one of the hydraulic actuators under predetermined conditions at a time of operation of the operation device is operated, wherein
the control device further includes an operation determination section that determines, based on an operation performed on the operation device, whether the work device is engaged in a work preparation operation for moving the work tool to the work start position,
when the pivot speed of the arm is zero, the operation determination section determines that the work device is engaged in the work preparation operation, and
when the operation determination section determines that the work device is engaged in the work preparation operation at the time of operation of the operation device, the actuator control section executes machine control to control a target hydraulic actuator such that an angle of the work tool with respect to a target surface indicative of a target shape of a work target for the work device coincides with a preset target angle, the target hydraulic actuator being one of the hydraulic actuators and related to the work tool.

7. A work machine that performs work by operating an arm after moving a work tool to a work start position, the work machine comprising:
a work device that includes a boom, the arm, and the work tool;
a plurality of hydraulic actuators that drive the work device;
an operation device that instructs the work device to operate in accordance with an operator's operation; and
a control device that includes an actuator control section for controlling at least one of the hydraulic actuators under predetermined conditions at a time of operation of the operation device is operated, wherein
the control device further includes an operation determination section that determines, based on an operation performed on the operation device, whether the work device is engaged in a work preparation operation for moving the work tool to the work start position
when a pivot speed for a dumping operation of the arm is equal to or lower than a predetermined value, or when the pivot speed of the arm is equal to or lower than the predetermined value and a lowering operation of the boom is performed, the operation determination section determines that the work device is engaged in the work preparation operation, and
when the operation determination section determines that the work device is engaged in the work preparation operation at the time of operation of the operation device, the actuator control section executes machine control to control a target hydraulic actuator such that an angle of the work tool with respect to a target surface indicative of a target shape of a work target for the work device coincides with a preset target angle, the target hydraulic actuator being one of the hydraulic actuators and related to the work tool.

Assignees

• Hitachi Construction Mach Co

Inventors

• Narikawa Ryu
• Edamura Manabu
• Sakamoto Hiroshi
• Izumi Shiho
• Moriki Hidekazu

Classifications

• E02F3/437

  providing automatic sequences of movements, e.g. linear excavation, keeping dipper angle constant · CPC title

• E02F9/22

  Hydraulic or pneumatic drives {(for dipper or bucket arm position control E02F3/43, for blade position control for graders E02F3/844; for turntables E02F9/121; for fork-lift trucks B66F9/22)} · CPC title

• E02F9/262

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

• E02F3/439 Primary

  Automatic repositioning of the implement, e.g. automatic dumping, auto-return (E02F3/438 takes precedence) · CPC title

• E02F3/431 Primary

  for bucket-arms, front-end loaders, dumpers or the like · CPC title