Motor Vehicle Door Unit With Switchable Freewheel

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Solution Overview

Problem

Existing door units for motor vehicles are technologically complex and require increased operating forces, contradicting modern comfort requirements, while aiming to allow smooth door movement and optional fixation without causing collisions with obstacles.

Innovation Solution

A door unit with a movable switching element relative to a holding element within the freewheel unit, interacting with a damping element that changes positions based on drive shaft speed, allowing unhindered pivoting or blocking of the door leaf, utilizing a switchable freewheel unit with freewheel elements that can be stored in a cage, and actuated by the door leaf's force and speed without external drives.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a blocking mechanism is used to prevent door collisions, then safety is improved, but device complexity increases

Engineering Contradiction:
ImprovesafetyVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the blocking mechanism with the existing drive shaft and coupling member into a single integrated assembly. The coupling member with variable closing force is merged with the drive shaft, eliminating the need for separate blocking devices and reducing overall system complexity while maintaining collision prevention functionality

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The coupling member serves multiple functions: it transmits motion from the drive shaft, provides variable closing force through spring pressure, and acts as a blocking mechanism when obstacles are detected. This multi-functionality eliminates the need for separate dedicated blocking devices, reducing device complexity while improving safety

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If a blocking mechanism is used to prevent door collisions, then safety is improved, but operating forces increase

Engineering Contradiction:
ImprovesafetyVSAvoidoperating forces
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The coupling member's closing force is made variable through spring pressure that can be adjusted based on operating conditions. The spring force dynamically adapts to provide sufficient blocking capability when needed while reducing resistance during normal door operation, thereby maintaining safety without increasing overall operating forces

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of closing force from fixed to variable by using spring pressure. The spring constant and pre-compression can be optimized to provide high blocking force when obstacles are present while requiring minimal force during normal door movement, resolving the contradiction between safety and operating force requirements

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a coupling member with variable closing force is used, then door locking reliability is improved, but device complexity increases

Engineering Contradiction:
Improvedoor locking reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The coupling member with variable closing force is integrated directly into the drive shaft assembly, merging the locking mechanism with the motion transmission system. This eliminates the need for separate locking devices and reduces overall device complexity while maintaining improved door locking reliability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The coupling member simultaneously provides motion transmission from the drive shaft and variable closing force for reliable door locking. By combining these functions in a single component, the patent achieves improved locking reliability without proportionally increasing device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 provides a structurally simple and cost-effective mechanism for stepless door locking, allowing the door leaf to move freely or be blocked as needed, enhancing user comfort and reducing operational complexity.

Implementation Method 1

interacting with a damping element which, when a certain minimum/ Limit speed of the drive shaft carries out an associated movement of its housing

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Data Source

PatentEP2640918B1Door unit
Publication Date: 2018.09.19 KIEKERT AG
  • EP2640918B1 patent drawingFigure 1
  • EP2640918B1 patent drawingFigure 2
  • EP2640918B1 patent drawingFigure 3

AI summary

The invention relates to a door unit, especially a motor vehicle door unit, comprising a movement transfer member (3, 4) connected to a door leaf (1) and provided with a drive shaft (4) and a coupling member (5) acted on by the drive shaft (4) and having a variable closing force. The coupling member (5) is provided with a switchable free-wheel unit (12, 13, 15).