Bistable Valve for Automotive Articulation Locking

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Solution Overview

Problem

Existing towable road motor vehicles face safety issues due to power failures affecting the controllable locking mechanism, leading to unintended changes in road holding and handling difficulties when detached or part of a convoy.

Innovation Solution

A road motor vehicle equipped with a bistable valve mechanism that maintains its locked or unlocked position without consuming energy, ensuring stability even in the absence of electrical power, thus preventing accidental changes in articulation and maintaining vehicle control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a controllable locking mechanism is used to maintain locked or unlocked position, then the vehicle can be securely attached or detached, but the mechanism requires permanent power supply which causes safety issues during power failure

Engineering Contradiction:
Improvelocking mechanism stabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The locking mechanism transitions from a continuously powered system to a bistable system that dynamically maintains one of two stable states (locked or unlocked) without continuous energy input. The mechanism uses spring elements and lugs that engage with corresponding features on the piston to create self-sustaining stable positions, eliminating the need for permanent power supply while maintaining reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The mechanism uses periodic or intermittent action through the bistable valve that switches between two stable states. Once switched to a desired state (locked or unlocked), the mechanism remains in that state without requiring continuous power, as the bistable design inherently maintains the position through mechanical means until another switching action occurs.

Inventive Principle:
Principle #19Periodic action

2Ease of operation

If the locking mechanism is permanently powered to maintain position, then the vehicle handling is controlled, but power failure causes accidental position changes leading to safety problems

Engineering Contradiction:
Improvevehicle handling controlVSAvoidpower failure impact
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The bistable mechanism incorporates mechanical cushioning through spring elements and lugs that prepare the system to maintain position even when power fails. The springs are pre-loaded to provide restoring force that keeps the piston in its current stable position, cushioning against any disturbances that might occur during power failure and preventing accidental position changes.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The locking mechanism becomes self-sustaining in each stable state, using its own mechanical components (springs, lugs, pistons) to maintain the locked or unlocked position without external power. The system serves itself by using the stored mechanical energy in the springs to counteract disturbances and maintain the desired state autonomously during power failures.

Inventive Principle:
Principle #25Self-service

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 ensures continued safe handling and road holding whether the vehicle is detached or hitched, as the locking mechanism remains stable without energy consumption, preventing accidents and handling difficulties during power failures.

Implementation Method 1

a controllable locking mechanism capable of switching, alternately, between: a locked position, in which it locks the joint in a position where the front and rear parts of the vehicle frame are aligned with each other, and an unlocked position, in which the front and rear parts are free to pivot, relative to each other, in rotation around the articulation axis, as long as the front hitch of this vehicle is hitched, this mechanism comprising for this purpose a cylinder interposed between the front and rear parts, this cylinder comprising a cylinder and a piston mounted to slide inside the cylinder along a longitudinal axis, this piston dividing the cylinder into a front chamber and a rear chamber each filled with an actuation fluid

Methodology Applied
Scientific EffectBistable mechanism: Metastability

Implementation Method 2

a controllable locking mechanism capable of switching, alternately, between: a locked position, in which it locks the joint in a position where the front and rear parts of the vehicle frame are aligned with each other, and an unlocked position, in which the front and rear parts are free to pivot, relative to each other, in rotation around the articulation axis, as long as the front hitch of this vehicle is hitched, this mechanism comprising for this purpose a cylinder interposed between the front and rear parts, this cylinder comprising a cylinder and a piston mounted to slide inside the cylinder along a longitudinal axis, this piston dividing the cylinder into a front chamber and a rear chamber each filled with an actuation fluid

Methodology Applied
Scientific EffectHydraulic actuation: Hydraulic Press

Data Source

PatentEP3642059B1Couplable automotive road vehicle
Publication Date: 2021.04.28 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP3642059B1 patent drawingFigure 1A~2
  • EP3642059B1 patent drawingFigure 3~6

AI summary

The claimed couplable automotive road vehicle comprises a controllable mechanism (50) for locking a joint between the rear and front parts of the vehicle, the mechanism (50) comprising a bitstable distributor (120) movable, in response to a command, between: - a first stable state (122) in which it stops the circulation of an actuation fluid to achieve a locked position of the locking mechanism, and - a second stable state (124) in which it allows the actuation fluid to flow into and out of, alternatingly, the front chamber (102) and rear chamber (104) of an actuator (80) in order to achieve an unlocked position of the locking mechanism, it being possible for the first and second stable states (122, 124) to be maintained without consuming energy.