Nested Piston Park Release Valve for Trailer Pneumatic Brakes
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Solution Overview
Problem
Existing park release valves for trailer vehicles with pneumatic brake systems are complex and prone to unwanted pressure equalization between reservoir pressure and supply connections, lacking a compact and high-functional design.
Innovation Solution
A park release valve with an outer and inner control piston, allowing movement between three positions, including a release position, driving position, and parking position, with spring-loaded detents for secure positioning, and featuring a non-return valve to prevent air flow from the reservoir into reduced pressure regions, ensuring compactness and functionality while preventing pressure equalization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a park release valve with combined functionalities is designed to be compact, then the device complexity is reduced and space is saved, but the reliability may worsen due to potential unwanted pressure equalization between reservoir pressure and supply connections
Solution Approach 1:
The valve is divided into two separately operable valve units: a first valve unit with a first control piston for controlling pressure to spring brake cylinders, and a second valve unit with a second control piston for controlling pressure to service brake cylinders. This segmentation allows each valve unit to independently control different pressure circuits, preventing unwanted pressure equalization while maintaining a relatively compact overall structure.
Solution Approach 2:
The first control piston is arranged inside the second control piston, creating a nested configuration. The first control piston has a smaller diameter and is positioned coaxially within the second control piston. This nesting arrangement allows both valve units to occupy the same spatial envelope, achieving compactness without compromising the independence of pressure control for each brake system.
2Reliability
If separate lines for reservoir pressure and supply pressure are used, then the reliability of pressure control is improved, but the device complexity increases
Solution Approach 1:
Both valve units share a common valve body and operate within the same housing structure. The first and second control pistons are arranged coaxially within the same cylindrical space, with the first piston nested inside the second piston. This merging of structural elements into a unified valve assembly reduces overall device complexity while maintaining separate pressure control lines through the distinct control piston mechanisms.
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 solution provides a compact and high-functional park release valve that effectively manages pressure transitions, preventing unwanted equalization and ensuring reliable operation of spring-loaded brake cylinders, enhancing the maneuverability and safety of trailer vehicles.
Implementation Method 1
the inner control piston is acted upon by reservoir pressure and presses against the outer control piston
Implementation Method 2
featuring a non-return valve to prevent air flow from the reservoir into reduced pressure regions
Data Source
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AI summary
The invention relates to a parking/release valve for a trailer with a pneumatic braking system and for controlling the pressure in spring-applied brake cylinders. It includes an outer control piston, an inner control piston, a connection for reservoir pressure, a connection for venting, and a pressure outlet. The outer control piston is movable between three positions: a release position, a driving position, and a parking position. In the driving position, the inner control piston is pressurized with reservoir pressure and presses against the outer control piston, such that the movement of the outer control piston is restricted and the outer control piston cannot assume a release position.