Motor Vehicle Door Unit Slipping Clutch Speed Control
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Solution Overview
Problem
Existing door units for motor vehicles lack a structurally simple mechanism to enable smooth movement of the door leaf while allowing it to be fixed when necessary, preventing collisions with obstacles during opening.
Innovation Solution
A door unit with a slipping clutch mechanism, where the clutch is triggered based on the rotational speed of the drive shaft, utilizing friction elements with a variable wrap cross section that can be adjusted by an actuating element to engage or disengage depending on the speed, allowing the door leaf to move freely at high speeds and be blocked at lower speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring-loaded coupling device with variable closing force is implemented to prevent collisions, then the door leaf can be fixed when required, but the structural complexity increases
Solution Approach 1:
The friction element is designed with a variable cross-sectional area that changes dynamically based on drive shaft rotational speed. At low speeds, the cross-sectional area is larger to provide high friction force for collision prevention. At high speeds, the cross-sectional area reduces to minimize friction and allow smooth door movement. This dynamic adaptation resolves the contradiction by making the safety mechanism active only when needed.
Solution Approach 2:
The invention changes the physical parameter of the friction element's cross-sectional area in response to rotational speed changes. The actuating element modifies the wrap angle or contact surface area of the friction element with the drive shaft based on speed thresholds, thereby adjusting the friction force parameter to match operational requirements without adding complex control systems.
2Reliability
If a friction brake device is used to dampen door movements, then the door leaf can be fixed when required, but the ease of operation deteriorates due to increased resistance
Solution Approach 1:
The friction element's cross-sectional area dynamically adapts to operational conditions: it is larger at low speeds to provide positioning force, and smaller at high speeds to reduce resistance during normal door operation. This dynamic behavior ensures the door moves smoothly during opening/closing while maintaining reliable positioning when needed.
Solution Approach 2:
The friction brake engages and disengages periodically based on rotational speed thresholds. During normal operation at high speeds, the friction element disengages to allow smooth movement. When the door approaches the closed position and speed decreases, the friction element engages to dampen movement and ensure precise positioning, creating a periodic engagement pattern that balances operation smoothness with positioning reliability.
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 allows the door leaf to move freely when the drive shaft exceeds a certain rotational speed, reducing resistance, and engages the clutch to block the door leaf when the speed decreases, effectively preventing collisions while maintaining a simple and cost-effective design without additional mechanical or electrical components.
Implementation Method 1
the friction element interacts with an actuating element to change its wrapping cross-section
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a door unit, in particular motor vehicle door unit, with a movement transmission element (3, 4) which is connected to a door wing (1) and has a drive shaft (4), and with a coupling element (5) which is acted upon by the drive shaft (4) with a variable closing force, wherein the coupling element (5) is designed as a sliding clutch (5) which can be triggered depending on the rotational speed of the drive shaft (4).