Closure Drive Brake Layout for High-Load Tailgate Operation

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Solution Overview

Problem

Existing drive arrangements for motor vehicle closure elements, such as tailgates and doors, face challenges with increased loads, leading to potential overload and disconnection due to enhanced braking forces, necessitating powerful and costly motors to manage snow loads and other additional weights.

Innovation Solution

The drive arrangement incorporates a load-dependent brake design that reduces braking effect with increasing load, allowing smaller, more cost-effective motors to be used by maintaining full braking effect during holding functions and reducing braking force during opening and closing operations, featuring a spindle-spindle nut gear and an overload clutch for protection against overload.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a powerful motor is used to overcome the increased braking force under load, then the drive arrangement can handle higher loads, but the production cost increases

Engineering Contradiction:
Improvemotor powerVSAvoidproduction cost
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

Instead of using a continuously powerful brake, the system employs a dynamic brake that adapts its braking force to the operational requirements. This allows a smaller, less expensive motor to be used since the brake does not continuously apply maximum force, only when needed for holding the closure element open.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The brake system is designed to automatically adjust its braking force based on the operational state without external control. The mechanical arrangement of brake components (lever arms, springs, lining pressure) causes the brake to self-regulate, providing high braking force for holding and low braking force for opening/closing operations.

Inventive Principle:
Principle #25Self-service

2Reliability

If full braking effect is applied during opening and closing operations, then the closure element can be held securely, but the motor requires higher power to overcome the braking force

Engineering Contradiction:
Improvesecure holdingVSAvoidmotor power requirement
Core Design Contradiction:
ReliabilityVSPower

Solution Approach 1:

The brake system applies different braking characteristics to different operational states. Full braking effect is locally applied only when the closure element needs to be held open (stationary position), while minimal braking effect is present during opening and closing movements. This spatial and temporal differentiation of braking quality optimizes both holding security and motor power requirements.

Inventive Principle:
Principle #3Local quality

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

This design enables reliable and cost-effective operation of closure elements under higher loads, including snow weights, by using smaller motors and preventing overload disconnection, thus reducing production costs and ensuring uniform movement.

Implementation Method 1

the braking effect of the brake is reduced with an increasing load in the drive train (8)

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

a spring arrangement (14) which is subjected to a greater tension, the friction surface (12a) of the rotatable component (16) moves away from the, in particular stationary, friction surfaces (12b) of the housing (1a)

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP3488064B1Drive arrangement of a closure element arrangement
Publication Date: 2024.10.09 BROSE FAHRZEUGTEILE GMBH & CO KG
  • EP3488064B1 patent drawingFigure 1
  • EP3488064B1 patent drawingFigure 2
  • EP3488064B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a drive arrangement of a closure element arrangement (2) of a motor vehicle (3), wherein the drive arrangement (1) has a drive motor (5) and a feed gear mechanism (6) arranged downstream of the drive motor (5) for generating linear driving movements along a geometric drive axis (7), wherein the drive motor (5) and the feed gear mechanism (6) are arranged in a drive train (8) of the drive arrangement (1) and the drive train (8) extends between two mechanical drive connections (9, 10) for channelling out driving movements and wherein the drive arrangement (1) has a brake (11) for braking at least one part of the drive train (8). It is proposed that the brake (11) is designed in such a way that the braking action of the brake (11) is reduced with an increasing load in the drive train (8).