Crawler Crane Boom Turn Restriction and Outrigger Gap Control
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Solution Overview
Problem
Existing mobile crane safety mechanisms hinder operability and workability, especially in remote operation modes, and fail to maintain stability during outrigger extraction, leading to potential accidents due to uneven ground contact or excessive height.
Innovation Solution
A mobile crane with a boom turn restriction control system that cancels restrictions when no operator is present, allowing 360-degree rotation and an outrigger extraction control system that adjusts outrigger length to maintain a stable gap between the crane body and ground, ensuring safety and stability during operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a boom turn restriction mechanism is provided to prevent the boom from turning above the driver seat, then safety is improved by preventing collision with the operator, but operability deteriorates in remote operation mode where 360-degree rotation is needed
Solution Approach 1:
The boom turn restriction mechanism is designed to dynamically adjust its restriction function based on the detected operation mode. When remote operation mode is detected, the mechanism automatically cancels the turn restriction, allowing 360-degree rotation. When local operation mode is detected, the restriction is activated to prevent the boom from turning above the driver seat. This dynamic adaptation resolves the contradiction by making the safety mechanism context-dependent rather than fixed.
Solution Approach 2:
The system changes the operational parameter of the boom turn restriction mechanism based on the operation mode. The restriction angle range is dynamically modified: in local operation mode, the boom is restricted from turning in the angular range above the driver seat, while in remote operation mode, the restriction is completely canceled to allow full 360-degree rotation. This parameter change enables the system to adapt safety constraints to operational context.
2Stability of the object's composition
If outriggers are extracted to support the crane body horizontally, then stability is improved, but the gap between the lower traveling body and ground surface becomes difficult to control, causing either ground contact damage or crane instability
Solution Approach 1:
The system incorporates a gap detection mechanism that continuously monitors the distance between the lower traveling body and the ground surface during outrigger extraction. The detection unit provides real-time feedback to the control unit, which automatically adjusts the outrigger extraction amount to maintain the gap within a predetermined safe range. This feedback control eliminates the need for manual gap estimation and ensures optimal stability without ground contact or excessive height.
Solution Approach 2:
The outrigger extraction control system performs self-adjustment based on automatic detection of the gap condition. The control unit independently manages the extraction process by detecting the actual gap and autonomously determining the appropriate extraction amount, without requiring external intervention or complex manual coordination. This self-service capability simplifies operation while ensuring precise gap control.
Data Source
Figure 1A~1C
Figure 2
Figure 3
AI summary
A crawler crane (1) includes: a seating switch (42) that detects whether an operator is in a driver seat (3); a turn angle potentiometer (41) that detects the turn position of a boom; and a controller (30) . The controller (30) is provided with a boom turn restriction control unit (40) for performing a boom turn-restricting control whereby the boom is not allowed to turn within a predetermined angular range above the driver seat (3) on the basis of the output from the turn angle potentiometer (41). The boom turn restriction control unit (40) includes a restriction0canceling unit (40B) that cancels the boom turn-restricting control performed by a turn-restricting unit (40A) if a preset restriction-canceling condition is met. The boom turn restriction control unit (40) cancels the boom turn-restricting control if the seating switch (42) does not detect an operator. Ease of operation and work can thus be improved in a remote operation mode and the like.