Overload preventing device

Patent metadata

Field	Value
Publication number	US-10919739-B2
Application number	US-201816635926-A
Country	US
Kind code	B2
Filing date	Aug 1, 2018
Priority date	Aug 8, 2017
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

This overload preventing device is mounted on a mobile work machine, and is provided with: a storage unit which stores lifting performance data in which lifting performance is configured for each operation state, and performance region data in which switching angles are configured that define performance regions, including a front region, a back region, and a side region; and a work machine control unit which controls operation of the mobile work machine on the basis of the actual load and the lifting performance corresponding to the present operation state of the mobile work machine. The lifting performance includes a maximum deployment width performance configured for the front region and the back region, and the switching angles are configured for each operation state on the basis of stability calculations and strength factors such as jack strength.

First claim

The invention claimed is:

1. An overload preventing device which is mounted in a mobile work machine which includes a travelling body which travels freely, a slewing base disposed on the travelling body to slewing horizontally, a boom disposed on the slewing base to be derricked, and a plurality of outriggers capable of setting an overhanging width in plural stages, the overload preventing device comprising:
a storage unit which stores lifting performance data in which a lifting performance is set for each operation state and performance region data in which a switching angle is set to define a performance region which includes a front region, a back region, and a side region; and
a work machine control unit which controls an operation of the mobile work machine on the basis of the lifting performance corresponding to a present operation state of the mobile work machine and an actual load, wherein
the performance region is set corresponding to a slewing state of the slewing base within a horizontal plane,
the front region is a performance region in front of the mobile work machine within the horizontal plane,
the back region is a performance region on a rear side of the mobile work machine within the horizontal plane,
the side region is a performance region other than the front region and the back region within the horizontal plane,
the lifting performance includes a maximum overhanging width performance which is set to the front region and the back region, and
the switching angle is set on the basis of a stability in all circumferential directions within the horizontal plane when the maximum overhanging width performance is loaded for each operation state.

2. The overload preventing device according to claim 1 ,
wherein the work machine control unit switches the performance region according to the operation state of the mobile work machine.

3. The overload preventing device according to claim 1 ,
wherein the operation state includes a boom length of the boom, a weight of a counter weight which is attached to the slewing base, and a type of an attachment device which is attached to the slewing base.

4. The overload preventing device according to claim 1 ,
wherein the maximum overhanging width performance includes a first performance which is set to all circumferential directions, and a second performance which is larger than the first performance, and
the switching angle includes a switching angle within a region where a first performance region in which the first performance is set in the front region or the back region, and a second performance region in which the second performance is set are defined.

5. The overload preventing device according to claim 1 , further comprising:
a display control unit which displays information related to the operation state to a display unit of the mobile work machine,
wherein the display control unit three-dimensionally displays a lifting performance chart generated on the basis of the lifting performance data and the performance region data using a cylindrical coordinates system in which a work radius is a radius direction, a slewing angle is a circumferential direction, and the lifting performance is an axial direction.

Assignees

• Tadano Ltd

Inventors

• Furuichi Kazuhiro

Classifications

• B66C23/78

  Supports, e.g. outriggers, for mobile cranes · CPC title

• B66C23/905 Primary

  electrical · CPC title

• B66C23/42

  with jibs of adjustable configuration, e.g. foldable · CPC title

• B66C23/90

  Devices for indicating or limiting lifting moment · CPC title

• B66C2700/0371

  on a turntable · CPC title