Rail Vehicle Seat Exhaust Flow Path Noise Reduction
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Solution Overview
Problem
Existing rail vehicle air-conditioning ventilator systems face challenges in preventing foreign matter entry into the exhaust air flow path and reducing noise transmission from the air-conditioning ventilator, with existing solutions either requiring excessive space for sound absorption materials or failing to effectively address low-frequency noise.
Innovation Solution
A rail vehicle design featuring a seat base with an opening or notch, an exhaust air flow path under the floor, an exhaust port communicating with the interior cabin, a lower tube portion, and an upper tube portion forming a return flow path structure where air flows between the outer and inner peripheries of these tubes, with a seat sound absorbing member to redirect airflow and absorb noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If sound absorbing material is attached to the cover of the exhaust port to reduce noise transmission, then noise reduction effect is improved, but the required thickness of the cover increases causing space conflict in the vehicle cabin
Solution Approach 1:
The patent combines multiple functions into the seat structure: the seat base opening serves as both a structural component and a noise absorption chamber. The space between the seat base and interior floor is utilized as an integrated sound absorption cavity, eliminating the need for separate thick sound absorbing covers while maintaining noise reduction effectiveness for low-frequency noise.
2Device complexity
If the exhaust port is positioned directly below seats to simplify structure, then device complexity is reduced, but foreign matter can easily enter the exhaust air flow path damaging the air-conditioning ventilator
Solution Approach 1:
The patent introduces the seat base structure as an intermediary protective element between the exhaust port and the vehicle cabin environment. The opening in the seat base acts as a controlled interface that allows exhaust air passage while the seat base itself serves as a protective barrier, preventing direct access of foreign matter to the exhaust port while maintaining the simplified structural arrangement.
3Manufacturing precision
If the exhaust air flow path is made linear to prevent fluid noise, then manufacturing precision is improved, but the ability to reduce low-frequency noise from the air-conditioning ventilator is compromised
Solution Approach 1:
The patent addresses low-frequency noise reduction by introducing a vertical dimension through the seat base opening structure. Instead of relying solely on horizontal flow path alignment, the invention creates a vertical sound absorption cavity between the seat base and interior floor, adding a dimensional approach to noise control that complements the linear flow path design and effectively targets low-frequency noise components.
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 effectively prevents foreign matter entry and reduces noise transmission from the air-conditioning ventilator, improving upon existing solutions by enhancing noise absorption, particularly for low-frequency sounds, while maintaining a simple and cost-effective structure.
Implementation Method 1
a seat sound absorbing member provided on a lower surface of a seat surface portion of the seat is disposed in a manner of facing the exhaust port
Implementation Method 2
when air flows from the inside of the vehicle cabin to the exhaust port via the return flow path structure, a direction of a flow passing between an outer periphery of the lower tube portion and an inner periphery of the upper tube portion is opposite to a direction of a flow passing through an inner side of the lower tube portion
Data Source
AI summary
A rail vehicle has a return flow path structure formed by a lower tube portion, an upper tube portion, a seat, and an opening or a notch of a seat base. When air flows from the inside of a vehicle cabin to an exhaust port connected to an exhaust air flow path under a floor via the return flow path structure, a direction of a flow passing between an outer periphery of the lower tube portion and an inner periphery of the upper tube portion is opposite to a direction of a flow passing through an inner side of the lower tube portion.