Compact Trailer Park Release Valve Design
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Solution Overview
Problem
Existing parking release valves for trailer vehicles with pneumatic brake systems are complex and lack a compact design, often leading to unintentional release of spring-loaded brakes during transition to a driving position, and fail to prevent unwanted pressure equalization between reservoir pressure and supply pressure connections.
Innovation Solution
A compact park release valve with a control piston and piston slide, allowing movement between three positions (release, driving, and parking) to prevent unintentional release, featuring a locking slide for additional safety and a modular design with check valves to prevent air flow from the reservoir into regions with reduced pressure, ensuring the spring-loaded brakes are only aerated when intended.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a compact park release valve design is implemented, then device complexity is reduced and ease of manufacture is improved, but reliability may worsen due to potential unintentional release during position transitions
Solution Approach 1:
The valve is divided into functionally independent components: a control piston for position control and a locking slide for safety locking. This segmentation allows each component to perform its specific function reliably while keeping the overall structure compact. The control piston manages the three positions (parking, driving, release), while the locking slide provides independent safety locking during transitions, preventing unintentional release.
Solution Approach 2:
The locking slide acts as an intermediary safety mechanism between the control piston and the brake system. During position transitions, the locking slide engages to prevent unintended brake release even if the control piston moves unexpectedly. This intermediary component ensures reliability without adding significant complexity to the valve structure.
2Reliability
If pressure isolation between reservoir and supply pressure connections is implemented, then reliability is improved by preventing unwanted pressure equalization, but device complexity increases
Solution Approach 1:
The valve internal structure is segmented into distinct pressure zones separated by sealed surfaces on the control piston and locking slide. These segmented zones isolate reservoir pressure from supply pressure connections, preventing unwanted pressure equalization. Each seal creates an independent pressure boundary, maintaining reliability without requiring complex additional components.
3Reliability
If check valves are added to prevent air flow from reservoir to reduced pressure regions, then reliability is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The check valve function is merged into the existing control piston and locking slide structure rather than being implemented as separate components. The sealed surfaces and pressure zones created by these components inherently prevent air flow from the reservoir to regions with reduced pressure. This integration maintains reliability while simplifying manufacturing compared to adding discrete check valves.
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, high-functionality valve that prevents unintentional release of spring-loaded brakes and ensures safe operation by maintaining pressure isolation between reservoir and supply pressure connections, enhancing safety and operational reliability.
Implementation Method 1
a control piston and a piston slide, b) a connection for reservoir pressure, a connection for reservoir pressure, an outlet for venting, a connection as pressure outlet
Implementation Method 2
In the driving position, the piston valve is acted upon by reservoir pressure and presses against the control piston in such a way that the control piston is restricted in its movement
Implementation Method 3
a special park-release valve is provided for this purpose, which, in a release position, aerates the spring-loaded brake cylinders with compressed air from the reservoir (of the trailer vehicle) and thus releases them
Implementation Method 4
The spring-loaded brakes are activated when the trailer vehicle is parked and separated from the towing vehicle because the spring-loaded brake cylinders are vented
Data Source
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AI summary
Parking release valve (23) for a trailer with pneumatic brake system and comprising: a control piston (69) and a piston valve (75), a connection for reservoir pressure (56), a connection for reservoir pressure (57), a venting outlet (73) and a pressure outlet connection (55).The control piston (69) is movable between three different positions: a release position, in which the connection for reservoir pressure (57) is connected to the connection as pressure outlet (55); a driving position, in which the connection for reservoir pressure (56) is connected to the connection as pressure outlet (55) or to the connection for reservoir pressure (57) and to the connection as pressure outlet (55); a parking position, in which the connection as pressure outlet (55) is connected to the outlet for venting (73); in the driving position, the piston valve (75) is pressurized with reservoir pressure (56) and presses against the control piston (69), such that the control piston (69) is restricted in its movement and cannot assume a release position.