Crane Luffing Aid Device for Heavy Boom Raising
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Solution Overview
Problem
Lattice boom cranes face limitations in raising long or heavy booms, as the existing bracing and retraction mechanisms reach their load-bearing capacity, requiring external aids like auxiliary cranes to avoid overloading.
Innovation Solution
A luffing aid device with a variable-length traction element and auxiliary arm is integrated into the crane, providing additional torque to assist in raising the boom, which can be actively controlled to support the initial lifting and serve as a fall-back support at steeper angles, preventing overloading of the bracing and retraction mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the bracing and retraction mechanism are used to raise the boom, then the existing system can support the boom, but the load-bearing capacity is exceeded when raising long or heavy booms
Solution Approach 1:
The raising function is segmented into two independent systems: the original bracing frame system and the new luffing aid device with auxiliary arm and traction element. This allows the original system to handle normal operations while the aid device handles the additional load of long/heavy booms, preventing overload of any single system.
Solution Approach 2:
The luffing aid device acts as an intermediary system between the ground and the boom during the raising process. The auxiliary arm and traction element provide an additional force path that supplements the bracing system, enabling the raising of booms that would otherwise exceed the bracing system's load-bearing capacity.
2Productivity
If the bracing system is used alone to raise heavy booms, then the system structure remains simple, but the retraction mechanism is overloaded beyond its load-bearing capacity
Solution Approach 1:
The lifting function is divided between two independent systems: the bracing system with retraction mechanism and the luffing aid device with auxiliary arm and traction element. This segmentation allows the retraction mechanism to operate within its safe load-bearing capacity while the aid device handles the additional weight of heavy booms.
Solution Approach 2:
The luffing aid device provides partial action by supplementing the bracing system only when needed for heavy or long booms. The aid device shares the loading responsibility, ensuring the retraction mechanism is never overloaded beyond its design capacity while still enabling the raising of heavier booms.
3Reliability
If external aids like auxiliary cranes are used to raise the boom, then the boom can be raised safely, but the device complexity and operational requirements increase
Solution Approach 1:
The luffing aid device is merged with the existing crane structure, with the auxiliary arm integrated onto the upper carriage and the traction element connecting to the boom. This integration eliminates the need for separate external auxiliary equipment while maintaining safety, reducing both device complexity and operational requirements compared to using external aids.
Solution Approach 2:
The auxiliary arm and luffing aid device are designed to be universally applicable to the crane's boom system, serving multiple functions: providing additional raising torque for heavy/long booms, supporting the boom during initial raising from flat position, and potentially serving as a fall-back support at steeper angles. This multi-functionality replaces the need for specialized external equipment.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables the safe and efficient raising of longer and heavier booms without external aids, by distributing the torque and reducing the load on the bracing and retraction mechanism, allowing for continuous operation without complex conversions.
Implementation Method 1
The traction element is thus arranged between the auxiliary arm and the boom designed to exert a tractive force on the boom in the direction of the auxiliary arm
Implementation Method 2
The luffing aid device comprises an auxiliary arm, which, on the one hand, is pivotably mounted on the upper carriage
Implementation Method 3
the bracing frame can be pivoted about its pivot axis by winding and unwinding a bracing cable onto and off of a cable winch on the upper carriage, thereby luffing the boom up and down
Implementation Method 4
This arrangement generates a torque that raises the boom in a vertical direction
Data Source
AI summary
The disclosure relates to a crane and a method for luffing the boom of a crane, in particular a mobile lattice boom crane, having an upper carriage and a boom articulated to the upper carriage so as to pivot about a horizontal axis. The boom is braced via a bracing frame mounted on the upper carriage and can be luffed up and down by pivoting the bracing frame. The crane comprises a luffing aid device, which can exert a torque acting in addition to the bracing on the boom for luffing the boom in a flat boom position. The luffing aid device comprises an auxiliary arm pivotably mounted on the upper carriage and connected to the upper carriage via a retaining element and to the boom via a variable-length traction element. The traction element exerts a tractive force on the boom in the direction of the auxiliary arm.