Flush Vehicle Door Handle Ratchet for Cable Slack Compensation
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Solution Overview
Problem
Conventional vehicle door handles protrude outward when not in use, leading to aerodynamic inefficiencies and potential issues with cable stretch over time, which can result in inconsistent deployment and reduced usability.
Innovation Solution
A door handle assembly with a recessed non-use position and a deployed use position, actuated by an electrically operated mechanism via a connection cable and ratchet design, which accommodates cable stretch and maintains tension, allowing the handle to be flush with the door when not in use and easily accessible when needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the door handle protrudes outward when not in use, then the handle is easily accessible and graspable by users, but it creates aerodynamic inefficiencies and increases air drag
Solution Approach 1:
The door handle is designed to dynamically change its position between a recessed state (when not in use) and a deployed state (when needed). The actuator mechanism enables the handle to move from the recessed position within the door surface to an extended position that protrudes outward, allowing users to grasp it. This dynamic positioning resolves the contradiction by having the handle protrude only when necessary for operation, minimizing aerodynamic drag during normal vehicle operation while maintaining ease of access when required.
2Device complexity
If a conventional cable connection is used without tension compensation, then the device complexity is reduced, but cable stretch over time leads to inconsistent handle deployment and reduced reliability
Solution Approach 1:
The connection mechanism incorporates a self-adjusting feature where the actuator is capable of detecting cable slack and automatically compensating for it. The system includes a tensioning mechanism that can take up slack in the cable over time, maintaining proper tension without requiring manual intervention. This self-service capability ensures reliable and consistent handle deployment throughout the vehicle's lifetime, resolving the reliability issue while keeping the overall system relatively simple.
Solution Approach 2:
The connection mechanism incorporates a feedback loop where the actuator monitors the tension and position of the cable-connected handle. Sensors detect when the handle is in the correct deployed or recessed position and when cable slack exceeds acceptable thresholds. Based on this feedback, the actuator automatically adjusts cable tension or triggers handle repositioning to maintain optimal operation, ensuring deployment consistency without significantly increasing device complexity.
3Object-affected harmful factors
If the handle is recessed when not in use, then aerodynamic performance is improved and air drag is reduced, but the handle becomes less accessible and harder for users to grasp
Solution Approach 1:
The door handle system dynamically transitions between recessed and deployed states based on user interaction or automated detection. When the vehicle is in motion or during normal operation, the handle remains recessed within the door surface to minimize aerodynamic drag and improve fuel efficiency. Upon detection of user approach (via sensors) or actuation signal, the handle quickly deploys to an accessible position that protrudes outward for easy grasping. This dynamic behavior resolves the contradiction by optimizing aerodynamics during non-use while ensuring ease of operation when needed.
Solution Approach 2:
The system performs preliminary actions by anticipating user needs through sensor detection (such as proximity sensors detecting a hand or body near the door). Before the user actually attempts to grasp the handle, the system preemptively deploys the handle from its recessed position to an accessible position. This preliminary action ensures the handle is already in the optimal graspable position when the user arrives, eliminating any delay or difficulty in operation while maintaining aerodynamic efficiency until the moment of use.
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 reduces air drag, enhances aerodynamic performance, and ensures consistent and reliable deployment of the handle over the vehicle's lifetime by maintaining cable tension, improving user accessibility and fuel efficiency.
Implementation Method 1
The connection mechanism includes a biasing element that biases the connection mechanism in a second direction to move the handle portion toward the recessed position when the actuator releases the cable. Responsive to tension in the cable being reduced by a threshold amount, the connection mechanism adjusts to increase tension in the cable.
Data Source
AI summary
A vehicular exterior door handle assembly includes a base, a handle movable relative to the base between recessed and deployed positions, an actuator that is operable to move the handle between the positions, and a connection mechanism that pivots relative to the base to move the handle between the positions. The actuator operates to pull and release a cable to pivot the connection mechanism to move the handle. The connection mechanism, when the actuator is operated to pull the cable, pivots in a first direction to move the handle from the recessed toward the deployed position. A biasing element of the connection mechanism biases the connection mechanism in a second direction to move the handle toward the recessed position when the actuator releases the cable. Responsive to cable tension being reduced by a threshold amount, the connection mechanism adjusts to increase tension.