Compact Park Release Valve for Trailer Pneumatic Brakes

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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 when transitioning from a parking to a driving position, and they fail to prevent undesired pressure equalization between reservoir pressure connections.

Innovation Solution

A compact park release valve design featuring a spool and control piston that can move axially between driving and parking positions, with a blocking element and unlocking mechanism to prevent unintentional release, and an additional valve body for controlling supply pressure, ensuring safe transition and preventing pressure equalization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a compact park release valve design is used, then device complexity is reduced and ease of manufacture is improved, but reliability may worsen due to potential unintentional release of spring-loaded brakes

Engineering Contradiction:
Improvevalve design complexityVSAvoidbrake release reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies preliminary anti-action by introducing a blocking element that prevents the control piston from moving to the release position until the supply pressure line is properly connected. This blocking mechanism acts in advance to prevent unintentional brake release, addressing the reliability concern while maintaining compact design.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent implements preliminary action by requiring supply pressure to be established before the blocking element is disengaged. The system performs the necessary pressure buildup and connection verification in advance, ensuring that brakes will not release unintentionally while keeping the valve design compact.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If a compact park release valve design is used, then ease of manufacture is improved, but the ability to prevent pressure equalization between reservoir pressure connections may worsen

Engineering Contradiction:
Improvevalve manufacturing easeVSAvoidpressure equalization prevention
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies preliminary anti-action by incorporating a blocking element that prevents pressure equalization between the supply pressure connection and reservoir pressure connection before proper system setup. This blocking mechanism is integrated into the compact valve design without significantly increasing manufacturing complexity.

Inventive Principle:
Principle #9Preliminary anti-action

3Reliability

If additional safety functions are integrated into the park release valve, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvebrake system safetyVSAvoidvalve functionality complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies merging by combining the blocking element, control piston, and valve body into a single integrated compact valve assembly. The additional safety function of preventing unintentional brake release is merged with the basic park/release valve functionality, avoiding the need for separate components and minimizing overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements multi-functionality by designing the control piston to serve dual purposes: controlling brake pressure release and interacting with the blocking element to prevent unintentional release. The blocking element itself serves multiple functions by preventing both unintentional brake release and premature pressure equalization, thereby improving reliability without proportionally increasing complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 park release valve that prevents unintentional release of spring-loaded brakes and ensures safe transition from parking to driving positions by controlling pressure equalization, enhancing safety and operational efficiency.

Implementation Method 1

the control piston is biased by a slide valve with an axially acting force in one direction from the driving position to the parked position

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

When pressure is applied at the supply pressure port, an axial force acts on the slide in a direction from the parked position to the operating position of the control piston

Methodology Applied
Scientific EffectPressure force: Pressure Increase

Data Source

PatentEP3481687B1Park-loose valve for a trailer
Publication Date: 2020.02.19 WABCO EURO BVBA SPRL
  • EP3481687B1 patent drawingFigure 1
  • EP3481687B1 patent drawingFigure 2
  • EP3481687B1 patent drawingFigure 3

AI summary

The invention relates to a park release valve for a trailer vehicle having a pneumatic brake system, and for controlling the pressure in spring-loaded brake cylinders, and having the following features: a) a connection for supply pressure, a connection for reservoir pressure, an output for ventilation, a connection as pressure output, b) a control piston for opening and blocking a connection from the connector for reservoir pressure to the connector as pressure output and for opening and blocking a connection from the output for ventilation to the connection as pressure output, c) the control piston is movable by an operating element between a travel position and a park position, wherein in the park position the connection from the output for ventilation to the connection as pressure output is opened and the connection from the connection for reservoir pressure to the connection as pressure output is blocked, d) the control piston is loaded in the park position and without pressure on the connector for supply pressure by a slider having an axially acting force in a direction from the travel position to the park position, e) in the event of pressure on the connector for supply pressure an axial force acts on the slider in a direction from the park position to the travel position of the control piston.