Steering Column Through Hole Stress Reduction
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Solution Overview
Problem
Existing steering devices with steering lock devices face stress concentration issues around through holes in columns made of aluminum alloy, leading to potential cracking under clamping force and torque application.
Innovation Solution
A steering device design featuring a flange section with a through hole providing clearance for the lock pin, a guide groove to guide the engaging convex part, and a bolt clamping system that reduces stress on the through hole by distributing the force through the flange section and ribs, allowing a smaller cross-sectional area for the through hole and increasing column strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the housing is clamped to the flange section using bolts, then the mounting rigidity between the column and the housing is enhanced, but the clamping force applied to around the through hole causes the column to be cracked
Solution Approach 1:
The guide groove acts as an intermediary structure between the engaging convex part and the through hole. It redirects the clamping force from the bolts away from the through hole area, transferring the load to the flange section instead, thus preventing stress concentration at the through hole while maintaining mounting rigidity.
2Manufacturing precision
If the engaging convex part is tightly fitted in the through hole, then the positioning accuracy of the steering lock device is improved, but the bending moment applied to the lock pin causes large stress to be applied to around the through hole to possibly crack the column
Solution Approach 1:
The guide groove serves as a mediator that guides the engaging convex part into proper alignment without requiring a tight fit in the through hole. This reduces the transmission of bending moments to the through hole area while maintaining sufficient positioning accuracy for the steering lock device.
Solution Approach 2:
The guide groove provides localized guidance and support in a specific region, allowing the engaging convex part to be positioned accurately without requiring the entire through hole area to bear the loading forces. This local quality approach distributes stress more favorably.
Data Source
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AI summary
In a steering device having a steering lock device, the stress applied to around a through hole formed in a column to which the steering block device is attached is reduced. Since there is a slight clearance formed, in the vehicle height direction, between the outer periphery of the lock pin (66) and the through hole (45) and also between the guide groove (46) and the engaging convex part (65), the clamping force is born by the flange section (43) and ribs (432) and (433) and also by the flange section (44) and ribs (442) and (443) without any force applied to the through hole (45). The engaging convex part (65) is not fitted in the through hole (45), so that the through hole (45) is only required to be large enough to allow the lock pin (66) whose cross-sectional area is smaller than that of the engaging convex part (65) to come in and out. This makes it possible to reduce the cross-sectional area of the through hole (45) and thereby increase the strength of the outer column (4).