Vehicle Door Assistance Device with Spiral Spring and Counterweight

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Solution Overview

Problem

Existing motor vehicle opening systems require significant user effort for opening and closing, with assistance devices like balancers being complex, costly, and bulky, and automatic closing is inconvenient, leading to poor locking of the leaf in the closed position.

Innovation Solution

A compact and reliable assistance device with a spiral spring and drive mechanism, allowing the sash to open automatically under the sole action of the jack and close under gravity, featuring a bistable drive mechanism and amplitude limiting means to optimize the lever arm and force efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If assistance devices like balancers are used to enable automatic opening, then user effort for opening is reduced, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improveuser effort for openingVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent employs a mechanical counterweight system where a lever arm with adjustable counterweight balances the sash weight. The counterweight compensates for the sash weight through gravitational force, enabling automatic opening without complex motorized assistance devices. The balance is achieved by positioning the counterweight at a specific distance from the rotation axis, creating a moment that offsets the sash weight moment.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The patent introduces dynamic adjustability through an adjustable counterweight position and a movable anchor point for the assistance cylinder. These dynamic elements allow the system to adapt to different sash weights and opening requirements, providing flexible assistance without requiring complex electronic control systems or multiple fixed configurations.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If assistance devices like balancers are used to enable automatic opening, then user effort for opening is reduced, but manufacturing cost increases

Engineering Contradiction:
Improveuser effort for openingVSAvoidmanufacturing cost
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The patent employs a mechanical counterweight system where a lever arm with adjustable counterweight balances the sash weight. The counterweight compensates for the sash weight through gravitational force, enabling automatic opening without complex motorized assistance devices. The balance is achieved by positioning the counterweight at a specific distance from the rotation axis, creating a moment that offsets the sash weight moment.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The patent replaces expensive, complex motorized assistance devices with simple, inexpensive mechanical components including a lever arm, counterweight, and assistance cylinder. These basic mechanical elements are much cheaper to manufacture and install while achieving the same functional effect of automatic opening through pure mechanical advantage and gravitational balance.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Device complexity

If assistance devices are made compact and simple, then integration into vehicle is easier, but assistance performance may be reduced

Engineering Contradiction:
Improvedevice complexityVSAvoidassistance performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces dynamic adjustability through an adjustable counterweight position and a movable anchor point for the assistance cylinder. These dynamic elements allow the system to adapt to different sash weights and opening requirements, providing flexible assistance without requiring complex electronic control systems or multiple fixed configurations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent utilizes parameter changes in the form of adjustable geometric relationships - the counterweight distance from the rotation axis and the anchor point position of the assistance cylinder can be modified to optimize performance. This allows the same simple mechanical structure to provide reliable assistance across different vehicle configurations and sash weights.

Inventive Principle:
Principle #35Parameter changes

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 automatic opening and partially automatic closing of the vehicle opening, improving user convenience and reliability with a simple, mechanical solution that integrates seamlessly into vehicle architecture without additional motorization or complex components.

Implementation Method 1

The assistance device includes a spring between the first structure and the second structure. The spring is a spiral spring.

Methodology Applied
Scientific EffectSpring energy storage: Spring

Implementation Method 2

so that the opening closes, under the sole action of the force of gravity on the opening

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP3477030B1Assistance device for a door leaf of a vehicle
Publication Date: 2020.12.30 RENAULT SA
  • EP3477030B1 patent drawingFigure 1
  • EP3477030B1 patent drawingFigure 2~3
  • EP3477030B1 patent drawingFigure 4~5

AI summary

Assistance device (100) for an opening (20) of a motor vehicle (1), characterized in that it comprises: - a first structure (110) intended to be fixed to a body (10) or to an opening (20) of a motor vehicle (1), and - a second structure (120) comprising an anchor point (124) intended to be fixed to a cylinder (30) for assisting the closing and/or opening of an opening (20), the second structure (120) being movable relative to the first structure (110).