Motor Vehicle Door Lock Drive Unit Manual Reversal Mechanism

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Solution Overview

Problem

Existing drive units for automotive applications, such as motor vehicle door locks, are mechanically complex and costly due to the need for large and expansive electric motor drives, which are also heavy, especially when they fail and require manual intervention for emergency closure.

Innovation Solution

A drive unit with a manually actuated manipulation element that can be moved from a basic position to an engagement position to reverse the electric motor drive, allowing for manual operation of the drive unit without the need for a large electric motor, using a spring-loaded mechanism and a pinion engaging with a worm wheel, reducing the size and weight of the electric motor drive.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the electric motor drive is made large and expansive to ensure sufficient torque for emergency closing, then the reliability is improved, but the weight and cost increase

Engineering Contradiction:
Improveemergency closing capabilityVSAvoidelectric motor drive weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The drive system is segmented into two independent parts: a small electric motor drive for normal operation and a separate manual manipulation element for emergency closing. This segmentation allows each component to be optimized independently, with the electric motor being small and lightweight while the manual mechanism provides the necessary emergency torque.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A manipulation element with pinion and worm gear acts as an intermediary mechanism between the user's manual input and the drive system. This intermediary provides mechanical advantage through the worm gear's self-locking property, enabling a small electric motor to suffice while manual intervention can still deliver high torque when needed.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the electric motor drive is made large and expansive to handle all operations including emergencies, then the productivity is improved, but the device complexity increases

Engineering Contradiction:
Improveoperational efficiencyVSAvoiddrive unit complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The drive system is divided into a standard electric motor drive unit and a separate manual manipulation element. This segmentation allows the electric motor to be small and simple for normal operations, while the manual mechanism handles emergency cases, reducing overall system complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The manipulation element serves multiple functions: it can manually actuate the drive in case of electric motor failure, perform emergency closing operations, and potentially assist in positioning. This multi-functionality eliminates the need for oversized motors while maintaining operational efficiency.

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

3Ease of operation

If the manipulation element is connected to the output element of the electric motor drive, then the ease of operation is improved, but the electric motor drive becomes larger and bulkier

Engineering Contradiction:
Improvemanual actuation capabilityVSAvoidelectric motor drive volume
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The manipulation element is designed as a separate, integrated component rather than being connected to the electric motor output. It has its own pinion that engages with the worm gear, allowing it to independently actuate the drive without requiring a large motor.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pinion on the manipulation element acts as an intermediary that directly engages the worm gear, bypassing the need for a large motor. This intermediary mechanism provides the necessary mechanical advantage for manual operation while keeping the electric motor compact.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If a spring is added as a mechanical energy storage device to enable manual opening, then the reliability is improved, but the device complexity increases

Engineering Contradiction:
Improvemanual opening capabilityVSAvoidmechanical components quantity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The worm gear's self-locking property is utilized to maintain the drive's position without requiring additional spring mechanisms. The geometry of the worm gear naturally prevents reverse motion, providing the necessary holding function through its inherent mechanical design rather than additional components.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent removes the need for separate spring-based energy storage devices by leveraging the self-locking characteristic of the worm gear. This extraction of unnecessary components simplifies the overall mechanism while maintaining the ability to hold position during manual operations.

Inventive Principle:
Principle #2Taking out (Extraction)

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

Enables cost-effective, reduced-weight, and simplified manual reversal of the drive unit in case of electric motor failure, ensuring the motor vehicle door lock can be closed and preventing unnecessary strain on the electric motor drive, while maintaining a compact design.

Implementation Method 1

a spring (17) which forces the manipulation element (13, 14) into its home position

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

The engagement element (14) has a pinion (21) which, in the engagement position of the manipulation element (13, 14), can be engaged with an external toothing of the worm wheel (8)

Methodology Applied
Scientific EffectWorm drive: Worm Drive

Data Source

PatentEP3847328B1Drive unit for motor-vehicle applications
Publication Date: 2022.12.14 KIEKERT AG
  • EP3847328B1 patent drawingFigure 1
  • EP3847328B1 patent drawingFigure 2
  • EP3847328B1 patent drawingFigure 3

AI summary

The invention relates to a drive unit for motor-vehicle applications, in particular an electromotive opening drive unit as a component of a motor vehicle lock, preferably a motor vehicle door lock, comprising a electromotive drive (6, 7, 8) for acting on a control element (4), and comprising a manually actuatable manipulation element (13, 14) which, at least in an engaged position with the electromotive drive (6, 7, 8), is designed for reversing same, characterised in that the manipulation element (13, 14) for reversing the electromotive drive (6, 7, 8) must first be transferred from a base position into the engaged position.