Mobile Work Machine Overload Control With State-Based Lifting Limits
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Solution Overview
Problem
Conventional overload preventing devices in mobile work machines do not maximize lifting performance based on varying operation states due to fixed switching angles dependent on outrigger states, leading to potential instability and reduced efficiency.
Innovation Solution
An overload preventing device that includes a storage unit for lifting performance data and performance region data, with adjustable switching angles based on stability calculations and strength factors for each operation state, allowing maximum utilization of the work machine's performance while ensuring stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fixed switching angles are used in conventional overload preventing devices, then the device structure is simple, but the lifting performance cannot be maximized based on varying operation states
Solution Approach 1:
The patent applies dynamics by making the switching angles adjustable rather than fixed. The control unit dynamically adjusts the switching angles based on detected operation states (boom length, work radius, slewing angle, outrigger overhanging width) to maximize lifting performance utilization. This allows the overload preventing device to adapt to varying operation conditions while maintaining safety.
Solution Approach 2:
The patent changes the parameter of switching angles based on operation states. Instead of using fixed switching angles, the system calculates and adjusts optimal switching angles according to the current operation state parameters (boom length, work radius, slewing angle, outrigger configuration). This parameter change enables the system to maximize lifting performance while ensuring stability.
2Productivity
If switching angles are adjusted based on each operation state, then lifting performance is maximized, but the calculation and control complexity increases
Solution Approach 1:
The patent implements feedback by using detection units to continuously monitor operation state parameters (boom length, work radius, slewing angle, outrigger overhanging width) and feeding this information back to the control unit. The control unit then adjusts the switching angles based on this feedback, creating a closed-loop system that maximizes lifting performance while maintaining stability through real-time monitoring.
Solution Approach 2:
The control unit serves multiple functions: it detects operation states, calculates optimal switching angles, determines lifting performance, and controls the overload prevention mechanism. This multi-functionality reduces the need for separate dedicated components for each function, managing complexity while achieving comprehensive operation state monitoring and performance optimization.
3Productivity
If maximum overhanging width performance is used in all regions, then lifting capacity is maximized, but stability is compromised in side regions
Solution Approach 1:
The patent applies local quality by setting different lifting performance levels for different performance regions (front, back, side). Instead of using maximum overhanging width performance uniformly across all regions, the system adjusts the lifting performance according to the specific region and operation state. This allows maximum lifting capacity in stable configurations while reducing capacity in less stable side regions, optimizing both productivity and stability locally.
Data Source
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AI summary
An overload preventing device is provided which, while ensuring safety, allows maximal utilization of lifting performance of a work machine depending on operation state. 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.