Work machine and method for controlling work machine

Patent metadata

Field	Value
Publication number	US-12454444-B2
Application number	US-202017609434-A
Country	US
Kind code	B2
Filing date	May 14, 2020
Priority date	May 17, 2019
Publication date	Oct 28, 2025
Grant date	Oct 28, 2025

Abstract

When a slewing motor is at a stop, a first slewing control unit of a controller that controls an operation of the slewing motor sets a first monitoring area that is set with respect to a slewing body as a designated area, and then controls, depending on whether an obstacle is detected in the first monitoring area, whether to prohibit or allow start of the slewing motor in response to a drive manipulation. Furthermore, a second slewing control unit of the controller sets one or more second monitoring areas that are set at places remoter from the slewing body than the first monitoring area as the designated area, and then controls, depending on whether the obstacle is detected in the second monitoring area(s), whether to limit the operation of the slewing motor in response to the drive manipulation after the start of the slewing motor is allowed.

First claim

The invention claimed is:

1. A work machine comprising:
a lower base;
a slewing body slewably located on an upper part of the lower base and coupled with a boom that supports a rope that suspends a hoist load;
a slewing motor that drives the slewing body;
an obstacle detection device located in the slewing body and detecting an obstacle existing in a designated area set within a unique monitoring range;
a slewing manipulation device including a slewing lever that receives a drive manipulation instructing the slewing motor to operate;
a controller that controls an operation of the slewing motor in response to the drive manipulation;
a hook for hanging the hoist load, the hook being supported by the rope; and
a winch configured to cause the hook to move up and down by winding or unwinding the rope,
wherein the work machine is a crane,
wherein the controller is configured to execute first monitoring control and second monitoring control,
in the first monitoring control, the controller is configured to set a first monitoring area that is set with respect to the slewing body as the designated area when the slewing motor is at a stop, when the obstacle is detected in the first monitoring area, the controller is configured to prohibit start of the slewing motor in response to the drive manipulation; and
in the second monitoring control, the controller is configured to set one or more second monitoring areas that are set at places remoter from a slewing center of the slewing body than the first monitoring area as the designated area, when the obstacle is detected in the one or more second monitoring areas, the controller is configured to set an operation limitation of the slewing motor, and start, with the operation of the slewing motor limited, the slewing motor in response to the drive manipulation,
wherein the first monitoring area is an area where the upper slewing body is configured to pass when the upper slewing body slews, and an area for detecting the obstacle that is configured to come into contact with the upper slewing body when the upper slewing body slews,
wherein the one or more second monitoring areas are areas where the upper slewing body does not pass when the upper slewing body slews, and areas for detecting the obstacle existing at a position where the obstacle does not come into contact with the upper slewing body when the upper slewing body slews.

2. The work machine according to claim 1 , wherein when the obstacle is detected in the one or more second monitoring areas, the controller performs speed limiting processing that is processing for limiting a rotation speed of the slewing motor, and
in the speed limiting processing, the controller is configured to operate the slewing motor in response to the drive manipulation within a range that does not exceed a predetermined speed limit.

3. A work machine comprising:
a lower base;
a slewing body slewably located on an upper part of the lower base and coupled with a boom that supports a rope that suspends a hoist load;
a slewing motor that drives the slewing body;
an obstacle detection device located in the slewing body and detecting an obstacle existing in a designated area set within a unique monitoring range;
a slewing manipulation device including a slewing lever that receives a drive manipulation instructing the slewing motor to operate; and
a controller that controls an operation of the slewing motor in response to the drive manipulation,
wherein the controller is configured to execute first monitoring control and second monitoring control,
in the first monitoring control, the controller is configured to set a first monitoring area that is set with respect to the slewing body as the designated area when the slewing motor is at a stop, when the obstacle is detected in the first monitoring area, the controller is configured to prohibit start of the slewing motor in response to the drive manipulation; and
in the second monitoring control, the controller is configured to set one or more second monitoring areas that are set at places remoter from a slewing center of the slewing body than the first monitoring area as the designated area, when the obstacle is detected in the one or more second monitoring areas, the controller is configured to set an operation limitation of the slewing motor, and start, with the operation of the slewing motor limited, the slewing motor in response to the drive manipulation,
wherein the one or more second monitoring areas include one second monitoring area that is set to correspond to a left slewing direction of the slewing body, and another second monitoring area that is set to correspond to a right slewing direction,
the obstacle detection device is configured to detect the obstacle individually in the one second monitoring area and the other second monitoring area,
the controller performs direction limiting processing,
in the direction limiting process, when the obstacle is detected in the one second monitoring area, the controller is configured to prohibit the operation of the slewing motor that slews the slewing body in the left slewing direction, and allow the operation of the slewing motor that slews the slewing body in the right slewing direction, and
in the direction limiting processing, when the obstacle is detected in the other second monitoring area, the controller is configured to prohibit the operation of the slewing motor that slews the slewing body in the right slewing direction, and allow the operation of the slewing motor that slews the slewing body in the left slewing direction.

4. The work machine according to claim 1 , wherein when the slewing motor starts with the operation of the slewing motor limited in the second monitoring control, the controller releases the limitation on the operation of the slewing motor on condition that the slewing motor stops, finished the second monitoring control, and then executes the first monitoring control.

5. The work machine according to claim 1 , wherein
the obstacle detection device is configured to be able to detect a position of the obstacle in the designated area,
the work machine further comprises:
a display device configured to display an image,
the controller is configured to set an invalid area when a predetermined invalid setting manipulation is detected under circumstances where the obstacle is detected in the designated area when the slewing motor is at a stop and a monitoring image of the designated area in which the obstacle is detected is displayed on the display device, the invalid area being an area including the position of the obstacle detected in the designated area corresponding to the monitoring image displayed on the display device,
the controller is configured not to execute control for prohibiting the start of the slewing motor in response to the detection of the obstacle in the invalid area when the invalid area is set, and the controller is configured not to execute control for limiting the operation of the slewing motor in response to the detection of the obstacle in the invalid area when the invalid area is set, and
the controller releases the setting of the invalid area when a predetermined invalidation release condition is satisfied.

6. The work machine according to claim 5 , further comprising:
a boarding and alighting cutoff device including a boarding and alighting cutoff lever that receives a preparatory manipulation of instructing the slewing motor to prepare for the operation and a predetermined suspend manipulation; and
a pilot pressure valve or a power supply cutoff circuit,
wherein the pilot pressure valve or the power supply cutoff circuit is configured to be able to shift a state of the slewing motor in response to the preparatory manipulation from a suspended state whe

Assignees

• Kobelco Constr Mach Co Ltd

Inventors

• Nakamura Arisa
• Teranishi Kentaro
• Sasai Shintaro

Classifications

• E02F9/264

  Sensors and their calibration for indicating the position of the work tool · CPC title

• E02F9/24

  Safety devices {, e.g. for preventing overload (E02F9/226 takes precedence)} · CPC title

• E02F9/2033

  Limiting the movement of frames or implements, e.g. to avoid collision between implements and the cabin (sub-groups of E02F3/431 of E02F3/435 take precedence; for turntables E02F9/123) · CPC title

• E02D13/06

  for observation while placing · CPC title

• B66C23/94

  for limiting slewing movements · CPC title