Steering Column Adjustment Drive With Slip Clutch Torque Limiting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing adjustment drives for steering columns in motor vehicles require fast adjustments over large ranges, which can lead to collisions with vehicle occupants, posing safety risks and comfort issues, especially during transitions between manual and autonomous driving modes.
Innovation Solution
An adjustment drive with a torque-transmitting slip clutch featuring friction surfaces and a preload device, including an elastic element and adjustable adjustment means, to manage the maximum drive torque and prevent collisions by slipping when the torque exceeds a defined limit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the adjustment speed is increased to achieve fast adjustment over large ranges, then the productivity is improved, but the object-affected harmful factors worsen due to potential collisions with vehicle occupants
Solution Approach 1:
The slip clutch is pre-configured with friction surfaces and pretensioning devices that establish a maximum torque limit before operation begins. This preventive mechanism ensures that when rapid adjustment is commanded, the system inherently cannot exceed the safe force threshold, cushioning against potential harm before it can occur.
Solution Approach 2:
The patent converts the potentially harmful effect of high adjustment forces into a beneficial safety feature. The slip clutch is designed to slip at a predetermined torque threshold, transforming what could be a dangerous collision force into a controlled slipping action that limits maximum force while still enabling fast adjustment movement up to that safe limit.
2Object-affected harmful factors
If the adjustment speed is reduced to minimize collision risk, then the object-affected harmful factors are improved, but the productivity deteriorates due to loss of comfort and adjustment time
Solution Approach 1:
The slip clutch enables parameter changes by allowing the adjustment speed to vary freely up to a maximum safe torque threshold. The friction-based slip clutch maintains a constant maximum force parameter while permitting speed optimization, allowing the system to operate at high speeds within safe force limits rather than requiring reduced speed for safety.
3Object-affected harmful factors
If a torque-limiting mechanism is added to prevent excessive force, then the object-affected harmful factors are improved, but the device complexity increases
Solution Approach 1:
The slip clutch acts as an intermediary element between the drive motor and the adjustment mechanism. This friction-based mediator automatically limits torque transmission through its slipping characteristic, providing torque control without requiring complex electronic sensors, control algorithms, or active regulation systems.
Solution Approach 2:
The slip clutch is a passive, self-regulating torque-limiting mechanism that automatically slips when the predetermined torque threshold is exceeded. It requires no external control systems, power supply, or active intervention to enforce the torque limit, making the adjustment drive inherently safe without adding complex control architecture.
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
The solution ensures high adjustment speed while minimizing the risk of injury by interrupting the adjustment process upon exceeding the maximum permissible force, maintaining comfort and safety during rapid adjustments.
Implementation Method 1
a pretensioning device which has an elastic element
Implementation Method 2
the slip clutch has friction surfaces which contact one another in a frictionally engaged manner
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present invention relates to an adjustment drive (5) for a steering column (1) for a motor vehicle, comprising a threaded spindle (52) which engages with an outer thread in a spindle nut (51, 61); and a drive unit (55) which is coupled to the threaded spindle (52) or the spindle nut (51) in such a way that the threaded spindle (52) and the spindle nut (51) can be driven relative to one another so as to be rotatable relative to one another. In order to ensure a higher safety level, the invention proposes that the drive unit (55) comprises a torque-transmitting slip clutch (8) which is coupled to the threaded spindle (52) or the spindle nut (51).