Rolling Joint Locking Device for Articulated Vehicle Stability
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Solution Overview
Problem
Four-wheel drive earth-moving machines with articulated frames face instability and risk of overturning, especially on steep terrain, due to the positioning of the center of gravity and variable load, which existing locking systems fail to address effectively without compromising wheel adhesion or requiring excessive space for locking devices.
Innovation Solution
A double-acting piston with a tangentially mounted cylinder and a rack-pinion mechanism at the rolling joint, controlled by an electronic unit processing signals from load sensors, allows selective locking of the pivoting direction to prevent tipping while maintaining adaptability to ground irregularities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hydraulic cylinders are mounted on frame parts to lock the rolling joint, then the vehicle stability is improved, but the space required for steering is reduced
Solution Approach 1:
The locking device is integrated directly into the rolling joint structure, merging the steering mechanism and locking mechanism into a single compact unit. The piston is received within the rolling joint housing, eliminating the need for separate hydraulic cylinders mounted on frame parts, thus preserving steering space while maintaining stability control
Solution Approach 2:
The piston and locking mechanism are nested within the rolling joint structure itself. The piston is received in a cavity formed in the housing of the rolling joint, with the pinion gear meshing with the rack on the trunnion. This nested arrangement allows the locking device to occupy minimal space within the existing steering mechanism
2Adaptability or versatility
If the rolling joint is positioned in the immediate vicinity of the vertical axis joint, then the wheel axles can adapt to ground irregularities, but the locking device requires excessive space
Solution Approach 1:
The locking mechanism is merged with the rolling joint structure, allowing the wheel axles to adapt to ground irregularities while the locking device occupies minimal space within the joint itself. The compact integration enables close positioning of the rolling joint to the vertical axis joint without space conflicts
3Reliability
If a locking system blocks pivoting movement in both directions, then vehicle tipping is prevented, but the adjustment of wheel axles to ground conditions is delayed
Solution Approach 1:
The locking action is applied selectively in only one pivoting direction at a time, rather than blocking both directions. The piston is positioned to engage the rack only when the vehicle is at risk of tipping in one direction, allowing free pivoting in the opposite direction for timely adjustment to ground conditions
Solution Approach 2:
The locking mechanism is dynamic and responsive, engaging only when needed based on vehicle stability conditions. The piston can engage the rack in one direction to prevent tipping while allowing free movement in the other direction, creating a dynamic rather than static locking system that adapts to changing terrain and load conditions
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
Ensures safety and maneuverability by locking only the pivoting direction that would cause instability, allowing free adjustment of wheel axles to ground conditions, with locking in both directions occurring only under specific load conditions, thus enhancing traction and comfort without impairing road adhesion.
Implementation Method 1
a double hydraulic circuit (C1, C2) which is connected to each other by shut-off valves (M1, M2) and check valves (Ra, Rb), said check valves being arranged so as to prevent the oil from escaping from the cylinder displacements (Va, Vb) but to allow the oil to enter in the opposite direction
Implementation Method 2
said shut-off valves (M1, M2) being connected to an electronic control unit (E)
Data Source
Figure 1
Figure 2~4
Figure 5~7a
AI summary
The device (D) has a double-acting piston (4) provided in a cylinder (3). The piston includes rack gears (4a) in a center area, where the rack gears comb with a toothed ring (11z). The toothed ring is firmly connected with a part of a roll hinge (1h). The cylinder is fixedly connected with another part (11a) of the roll hinge. Electromagnetic deflecting valves or cut-off valves are connected with an electronic control unit, and controlled by the control unit. The roll hinge is connected between parts of a hinge frame of a vehicle.