Vehicle Occupant Restraint with Pre-Collision Gap Enlargement
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Solution Overview
Problem
Existing occupant restraining devices for vehicles face challenges in effectively managing the kinetic energy of vehicle occupants during front collisions, particularly when collision velocity, occupant mass, or kinetic energy is high, leading to insufficient energy absorption.
Innovation Solution
An occupant restraining device that includes a seatbelt, a collision predicting sensor, a gap enlarging section, and an actuator, which enlarges the gap between the occupant and the seatback and rapidly retracts the seatbelt using an explosive-type pretensioner and electric motor before a collision, maintaining deceleration and restraining the occupant until the initial stage of the collision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the distance between the vehicle occupant and the steering wheel is increased at the time of advance sensing of a collision, then the occupant protection is improved, but in a case in which the vehicle collision velocity or the vehicle occupant mass or the like is large and the kinetic energy of the vehicle occupant is large, there is the possibility that the energy absorption will be insufficient
Solution Approach 1:
The system performs preliminary actions by enlarging the gap between the occupant and seatback, and retracting the seatbelt before the collision occurs. This preliminary preparation creates readiness for energy absorption during the collision event, allowing the seatbelt to effectively restrain the occupant from the initial stage of collision rather than waiting for contact to occur
Solution Approach 2:
The seatbelt retracting force is applied continuously from before the collision through the initial stage of the collision. This continuous application of restraining force ensures that the occupant is consistently decelerated throughout the critical energy absorption period, preventing any gap in protective action that would allow excessive kinetic energy to transfer to the occupant
2Object-affected harmful factors
If the strength of restraining a vehicle occupant by a seatbelt after a collision is controlled, then the vehicle body deceleration waveform that reduces the deceleration of the vehicle occupant appropriately is realized, but in a case in which the kinetic energy of the vehicle occupant is large, there is the possibility that the energy absorption will be insufficient
Solution Approach 1:
The seatbelt is retracted before the collision occurs, putting the occupant in a pre-restrained state. This preliminary action ensures that when the collision happens, the occupant is already being actively restrained rather than passively experiencing uncontrolled deceleration, enabling effective energy absorption from the very beginning of the collision event
Solution Approach 2:
The restraining action by the seatbelt continues uninterrupted from before the collision through the initial stage of the collision. This continuous restraining force ensures consistent energy absorption throughout the critical deceleration period, maintaining appropriate control over the occupant's deceleration waveform even when kinetic energy is large
3Loss of energy
If the gap between the vehicle occupant and the seatback is enlarged and the seatbelt is retracted before a collision, then the initial kinetic energy of the vehicle occupant is reduced, but the device complexity increases
Solution Approach 1:
The seatbelt system performs multiple functions: it acts as both a gap-enlarging mechanism (by retracting to create space between occupant and seatback) and an energy-absorbing restraining mechanism. This multi-functionality reduces the need for separate dedicated components, thereby limiting the increase in device complexity while achieving kinetic energy reduction
Solution Approach 2:
The gap enlargement and seatbelt retracting actions are performed in advance of the collision, preparing the system for optimal energy absorption. This preliminary preparation allows the existing seatbelt mechanism to be used more effectively rather than requiring additional complex energy-absorbing devices
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 device reduces the initial kinetic energy of the vehicle occupant by maintaining a decelerated state and ensuring effective energy absorption, improving occupant protection during front collisions.
Implementation Method 1
an explosive-type pretensioner and electric motor; and the control section operates the explosive-type pretensioner before a front collision of the vehicle
Implementation Method 2
an explosive-type pretensioner and electric motor; and from before the front collision at least until forward movement of the vehicle occupant starts, drives the electric motor
Implementation Method 3
enlarge the gap between the vehicle occupant and a seatback of the vehicle seat; the decelerated state, in which the ground speed of the vehicle occupant is slower than the ground speed of the vehicle
Data Source
AI summary
The occupant restraining device for a vehicle has a seatbelt, a collision predicting sensor, a braking device that enlarges a gap between a vehicle occupant and a seatback of a vehicle seat, an explosive-type pretensioner and electric motor that retract the seatbelt, and a control section that, in a case in which a front collision of the vehicle is sensed in advance by the collision predicting sensor, enlarges the gap between the vehicle occupant and the seatback by the braking device and starts retracting of the seatbelt by the explosive-type pretensioner and the electric motor, and at least until forward movement of the vehicle occupant starts after occurrence of the front collision, continues to input load to the vehicle occupant from the seatbelt and continues to move the vehicle occupant toward a vehicle rear side.