Vehicle Shade Constant Force Spring Guide Rail Mechanism
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Solution Overview
Problem
Existing shade devices for vehicles, such as roller blinds, often experience uneven extraction force, leading to excessive force at the start of deployment, which can cause noise and discomfort due to violent contact with the window frame, and require large spring motors to maintain extraction, resulting in excessive biasing force.
Innovation Solution
A shade device utilizing a constant force spring wound in a coil shape, with a rod guided within a guide rail, where the spring's biasing force is transmitted to the rod to maintain consistent extraction force throughout deployment, and a locking mechanism to manage the spring's energy efficiently, reducing noise and vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a spring motor with large biasing force is used to maintain extraction force at large extraction stages, then extraction force is sufficient throughout deployment, but excessive biasing force at start causes violent contact and noise
Solution Approach 1:
The patent changes the parameter of biasing force from variable (spring motor) to constant (constant force spring). The constant force spring maintains a substantially constant biasing force regardless of extraction amount, preventing both the insufficient force at large extraction stages and the excessive force at start that causes noise and violent contact.
2Power
If a spring motor is used for shade extraction, then extraction force can be generated, but the force varies with extraction stage causing inconsistent extraction performance
Solution Approach 1:
The patent replaces the spring motor with a constant force spring, changing the parameter of biasing force from variable to constant. This ensures that the extraction force remains substantially constant throughout the entire extraction process, providing consistent extraction performance regardless of the extraction stage.
3Force
If the constant force spring is allowed to expand freely, then biasing force is transmitted effectively, but the spring waves excessively causing instability
Solution Approach 1:
The patent introduces a guide rail as an intermediary component that constrains the constant force spring. The guide rail prevents excessive waving of the spring while allowing it to expand and transmit biasing force effectively, thus maintaining both force transmission and position stability.
4Device complexity
If the rod is not guided during movement, then the mechanism is simpler, but the rod and spring may contact improperly causing noise and inefficiency
Solution Approach 1:
The guide rail serves as an intermediary that properly guides the rod and constrains the constant force spring during movement. This prevents improper contact between components, eliminating noise and ensuring efficient force transmission, while adding minimal complexity to the mechanism.
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 achieves consistent and appropriate extraction force throughout the deployment process, reducing noise and discomfort, while maintaining compactness and minimizing damage to components, by efficiently transmitting the spring's biasing force and minimizing contact noise.
Implementation Method 1
a constant force spring (56) which generates force for biasing the rod (60) in the deploying direction of the shade (22) by restoring force of the constant force spring (56) returning from an expanded state to an original state
Data Source
AI summary
A shade device for a vehicle includes: a shade; a retracting mechanism attached to a base end of the shade and retracting the shade in a stored state; a stay attached to a tip end of the shade; an extractable constant force spring; a rod, its tip end portion being attached to the stay and its base end portion being connected to the constant force spring, biased in a deploying direction of the shade by biasing force of the constant force spring, and transmitting the biasing force to the stay; a guide rail that stores the rod and an extracted portion of the constant force spring in the stored state of the shade, and guides the rod when the shade shifts from the stored state to the deploying state; and a locking mechanism that locks movement of the rod in the stored state of the shade.