Vehicle Flap Device Shutter Noise Reduction via Stop Projections
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Solution Overview
Problem
Flap devices in motor vehicle fan units generate annoying closing noises due to the impact of shutters against stop surfaces when air flow ceases, affecting both conventional and electric/hybrid vehicles.
Innovation Solution
Incorporating stop projections on the first end of the shutter near the pivot axis, which contact the support structure at a lower velocity, reducing noise intensity by altering the impact point and potentially adding resilient deformability to the stop projections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the shutter strikes against the stop surface at the far end from the pivot axis, then the shutter achieves full opening/closing range, but the impact velocity is high generating annoying noise
Solution Approach 1:
The invention introduces stop projections at specific locations (near the pivot axis) rather than relying on the default far-end contact. This local modification changes where the impact occurs, reducing noise while preserving the shutter's full range of motion. The stop projections are strategically placed to intercept the shutter early in its closing path, before it reaches the far end where high-velocity impact would occur.
Solution Approach 2:
The stop projections act as intermediary elements between the shutter and the support structure. Instead of the shutter directly impacting the support structure at high velocity, the stop projections serve as intermediate contact points that absorb and dissipate impact energy, reducing the noise generated during closing.
2Object-generated harmful factors
If the stop projection is made resiliently deformable, then the impact noise is further reduced through energy absorption, but the manufacturing complexity increases
Solution Approach 1:
The invention allows the stop projection to be manufactured with different material properties, including resiliently deformable materials. By changing the physical parameter of the stop projection (from rigid to resilient), the impact characteristics are modified to reduce noise. The patent acknowledges this creates a trade-off with manufacturing complexity but presents it as an optional enhancement.
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 modified flap device significantly reduces noise intensity by changing the impact dynamics, making the closing noise practically negligible.
Implementation Method 1
the shutter or flap pivots from the lowered rest position towards the raised operating position under the effect of a flow of air which strikes it in this direction
Implementation Method 2
returns by gravity towards the rest position when the air flow ceases
Implementation Method 3
at least one stop projection is formed on one of the aforesaid first end of the shutter and the support structure and arranged to bear against an abutment surface formed on the other of the aforesaid first end of the shutter and the support structure when the shutter is in the rest position
Data Source
AI summary
A flap device for a heat exchanger of a vehicle has a support structure in which is formed a passage. A shutter is fitted to the passage, pivotable about an operationally horizontal axis (X-X) nearer to a first end of the shutter, between a rest position in which it closes the passage and a operating position in which it opens the passage, thereby allowing a flow of air to pass in a predetermined direction through the passage. In use, the shutter pivots from the rest position towards the operating position under the effect of a flow of air which strikes it in this direction, and returns by gravity towards the rest position when the air flow ceases. A stop projection formed on the first end of the shutter strikes an abutment surface on the structure when the shutter reaches the rest position.