Automotive Lid Force Balancer Roller Abutment Design

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Heavy force balancers used in vehicles with retractable roofs cause deformation of the door sash, leading to misalignments and appearance defects, making it difficult to close the door, and oversizing the arms to counteract these forces results in a bulky device that may not fit within the vehicle's trunk.

Innovation Solution

A device with a force balancer featuring a roller secured to the mobile end and an abutment on the vehicle, which includes a raceway with an inclined rectilinear and arcuate portion to manage the forces exerted by the balancer, ensuring proper alignment and minimizing deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the arms of the opening device are oversized to counteract the forces of the force balancer, then the deformation of the sash is reduced, but the device becomes bulky and may not fit within the available trunk volume

Engineering Contradiction:
Improvesash deformationVSAvoidopening device volume
Core Design Contradiction:
Stability of the object's compositionVSVolume of moving object

Solution Approach 1:

A roller is introduced as an intermediary element between the force balancer and the sash structure. The roller transmits the force from the balancer while concentrating it on a small contact area with the abutment, avoiding the need to oversized the entire arm structure. This mediator allows force transmission without requiring large structural dimensions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The design changes the geometric parameters of the force transmission path by introducing a curved raceway with specific radius R. This parameter optimization allows the roller to follow a controlled trajectory that minimizes deformation while maintaining compact arm dimensions, resolving the contradiction between stability and volume.

Inventive Principle:
Principle #35Parameter changes

2Force

If the force balancer exerts high forces to compensate for the heavy opening, then the opening can be facilitated, but the sash experiences deformation and misalignment of lock elements

Engineering Contradiction:
Improveforce balancer effortVSAvoidsash alignment
Core Design Contradiction:
ForceVSManufacturing precision

Solution Approach 1:

The abutment features a curved raceway with radius R instead of a straight or angular path. This curvature allows the roller to follow a smooth arc that naturally guides the force application point, maintaining sash alignment while the force balancer exerts its compensating force. The curved path prevents misalignment of lock elements by ensuring proper geometric relationship throughout the motion.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Ease of operation

If the arms are made with curved gooseneck shapes to ensure retention trajectory, then the opening motion is facilitated, but the required arm size increases significantly

Engineering Contradiction:
Improveopening motionVSAvoidarm volume
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The roller acts as a mediator that separates the gooseneck shape function from the structural arm dimensions. The roller follows the curved trajectory required for proper retention while being much smaller than the arm itself, allowing the arm to maintain a compact size without sacrificing the beneficial gooseneck motion characteristics.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution effectively limits door sash deformation, allowing for proper closure and maintaining a compact opening device design compatible with the vehicle's volume.

Implementation Method 1

a force balancer such as a jack including a spring which compresses or expands when the door is closed

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a roller rigidly secured to the mobile end of the force balancer, and an abutment secured to a fixed part of the vehicle and against which the roller comes to bear

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP1914099B1Device for opening a lid of an automobile
Publication Date: 2011.01.12 PEUGEOT CITROEN AUTOMOBILES SA
  • EP1914099B1 patent drawingFigure 1~4
  • EP1914099B1 patent drawingFigure 2~3
  • EP1914099B1 patent drawingFigure 5~6

AI summary

The device has a force stabilizer (2) in the form of a jack comprising a spring that is compressed/expanded during closing of a casement (1). The stabilizer has a fixed end (6) integrated to a fixed part of a vehicle, and a mobile end (7) integrated to the casement. A roller (9) is integrated to the mobile end, and a stop (8) integrated to the fixed part. The roller is supported on the stop when the casement is closed. The stabilizer exerts force to maintain the roller on the stop. The stop has a roller track (11) comprising a portion in the shape of a circular arc.