Air Control Valve Over-Center Cam Mechanism
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Solution Overview
Problem
Current air control valves in automobiles require continuous power to maintain the desired position, leading to increased electrical consumption, risk of motor failure, and added weight and cost due to the need for larger motors to compensate for heat-related issues, which is inefficient and costly.
Innovation Solution
An automotive air control valve utilizing an over-center cam mechanism that biases the blade to secure it in the open or closed position when the actuator is powered down, allowing for the use of smaller, less expensive DC brush electric actuators and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If continuous power is supplied to the electric actuator to maintain the valve in the desired position, then the valve position stability is improved, but the electrical power consumption increases
Solution Approach 1:
The over-center cam mechanism enables the valve to maintain its position automatically without continuous external power input. Once the electric actuator moves the valve to the desired position, the cam mechanism's geometry creates stable equilibrium points that hold the valve in place using only the spring bias force, eliminating the need for continuous electrical power to maintain position.
Solution Approach 2:
Instead of continuous power application, the system uses periodic action where the electric actuator only needs to provide brief pulses of power to transition the valve between stable positions. The over-center cam mechanism then maintains the position between these periodic actuations, significantly reducing overall power consumption.
2Reliability
If a larger electric motor is used to compensate for heat-related issues, then the motor reliability is improved, but the device weight and cost increase
Solution Approach 1:
The over-center cam mechanism allows the electric actuator to operate in short periodic pulses rather than continuous operation. This intermittent duty cycle prevents the motor from overheating, enabling the use of smaller, lighter motors that would otherwise be unreliable under continuous load conditions.
Solution Approach 2:
The over-center cam mechanism acts as an intermediary between the electric actuator and the valve. It amplifies the brief actuator movements into stable positional states, allowing a smaller actuator to control a larger valve system without requiring the actuator to continuously overcome the full spring bias force.
3Stability of the object's composition
If the electric actuator is held in a fixed position to maintain the valve open, then the valve position is maintained, but the risk of commutator burning and brush-commutator damage increases
Solution Approach 1:
The over-center cam mechanism provides self-latching functionality that maintains valve position without requiring the electric actuator to remain powered. The mechanical geometry of the cam creates stable equilibrium positions that automatically hold the valve open or closed, eliminating continuous electrical power requirements and preventing commutator and brush damage from prolonged stationary operation.
Solution Approach 2:
Instead of using continuous electrical power to maintain position (the conventional approach), the invention inverts the approach by using mechanical geometry and spring bias to maintain position, with electrical power applied only briefly for position transitions. This inversion eliminates the harmful effects of continuous electrical operation while maintaining position stability.
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
Enables the air control valve to remain in the desired position without continuous actuator power, optimizing space, weight, and cost while minimizing power consumption, thus improving efficiency and reducing the risk of motor failure.
Implementation Method 1
a spring having a first end and a second end, the first end of the spring being attached to a distal end of the cam arm and the second end of the spring being attached to a fixed structure
Data Source
AI summary
An automotive air control valve comprises a housing, the housing defining an air flow path, a blade pivotally mounted within the housing, the blade pivotable between a closed position, wherein the blade substantially blocks air flow through the housing, and an open position, wherein air can flow through the housing, an actuator adapted to selectively pivot the blade between the open and closed positions, a first stop that provides a positive stop for the blade when rotated to the open position, a second stop that provides a positive stop for the blade when rotated to the closed position; and an over-center cam mechanism, wherein the over-center cam mechanism is adapted to bias the blade in the open position when the blade has been pivoted to the open position, and to bias the blade in the closed position when the blade has been pivoted to the closed position.