Variable-Length Connecting Bar for Synchronized Steering in Tilting Forecarriages
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Solution Overview
Problem
Three-wheeled tilting motor vehicles experience uneven up-and-down movements of the front steered wheels, leading to potential steering discrepancies due to kinematic steering mechanisms, which can be perceived as defects by drivers during certain driving conditions.
Innovation Solution
A forecarriage design with a four-bar linkage and a variable-length first connecting bar, along with a fixed-length second connecting bar, that allows independent up-and-down movements of the front wheels while maintaining synchronized steering, preventing differentiated steering movements caused by unequal wheel movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a kinematic steering mechanism connects the two steered wheels to ensure synchronized steering, then steering synchronization is improved, but steering discrepancies occur when the wheels experience unequal up-and-down movements
Solution Approach 1:
The first connecting bar is made variable in length to dynamically adapt to unequal up-and-down movements of the two front wheels. This allows the connecting bar to change its length in response to wheel position changes, preventing the transmission of differential movements to the steering mechanism while maintaining steering synchronization.
Solution Approach 2:
The length parameter of the first connecting bar is changed dynamically based on the relative positions of the two front wheels. By adjusting this parameter (length) in response to wheel movements, the system absorbs differential movements without affecting steering synchronization.
2Device complexity
If a fixed-length connecting bar is used to connect the supporting members, then structural simplicity is improved, but steering discrepancies arise due to unequal wheel movements
Solution Approach 1:
The first connecting bar transitions from a fixed-length structure to a variable-length structure. This dynamic capability allows it to accommodate unequal vertical movements of the supporting members without inducing steering errors, while the second connecting bar maintains fixed length for structural simplicity where needed.
Solution Approach 2:
The connecting bar system is segmented into two distinct components: a first connecting bar with variable length that handles vertical movement compensation, and a second connecting bar with fixed length that provides structural stability. This segmentation allows each component to optimize its function independently.
Data Source
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AI summary
The forecarriage comprises: a forecarriage frame (111); a steering column tube (3), connected to the forecarriage frame (111); a four-bar linkage (17) connected to the forecarriage frame (111) which supports, by means of a first supporting member (31') and a second supporting member (31"), respectively a first front wheel (13') and a second front wheel (13"); a steering column (5) rotatingly housed in the steering column tube (3) and connected to a first connecting bar (41) which connects the first supporting member (31') and the second supporting member (31") to one another; a suspension system (51; 51'; 51") which allows a up-and-down movement of the first front wheel (13') and of the second front wheel (13") with respect to the four-bar linkage (17). The first connecting bar (41) has a variable length. A second connecting bar (71) connects the first supporting member (31') and the second supporting member (31") to one another. The second connecting bar (71) is connected at points which are neutral with respect to the up-and-down movements of the first front wheel (13') and the second front wheel (13").