Electromechanical Valve Device for Compressed-Air Brake Systems

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Solution Overview

Problem

Conventional valve devices for compressed air systems in motor vehicles, particularly in commercial vehicles, face challenges such as large size, noise generation, high drive energy requirements, and non-linear control due to solenoid valves, which are inadequate for fast anti-lock braking systems (ABS) and anti-slip control (ASR) applications.

Innovation Solution

A valve device with an electromechanical linear drive, featuring a valve piston and a separate ventilation piston with a prestressing device, operates as a three-point valve with large cross-sectional openings, minimizing drive energy and noise, and using an electromagnet or linear actuator for precise pressure control without pneumatic components, allowing for compact design and efficient energy use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If solenoid valves are used for pressure control in compressed air systems, then electrical control capability is achieved, but device size increases and noise is generated

Engineering Contradiction:
Improveelectrical control capabilityVSAvoiddevice size
Core Design Contradiction:
Extent of automationVSVolume of moving object

Solution Approach 1:

The patent extracts the pneumatic control components (solenoid valves, pilot devices, air volume-boosting valves) from the system and replaces them with a direct electromechanical linear drive. This removes the source of noise and reduces device size while maintaining electrical control capability through the linear motor that directly actuates the valve piston.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the pneumatic-mechanical control system (solenoid valves controlling pilot pressure controlling air volume-boosting valves) with a direct electromechanical system. The linear motor with voice coil motor technology provides direct electrical-to-mechanical conversion, eliminating intermediate pneumatic components and reducing overall device size.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Power

If solenoid valves with large effective areas are used to control brake pressure, then pressure control capability is improved, but drive energy requirements increase

Engineering Contradiction:
Improvepressure control capabilityVSAvoiddrive energy
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic pressure balancing on the valve piston through the second pneumatic connection that equalizes pressure between the first and second pneumatic spaces. This dynamic balancing reduces the net force required from the linear motor, lowering drive energy consumption while maintaining the ability to control large brake pressures.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the pressure parameters in the pneumatic spaces to achieve balance. By adjusting the pressure distribution across the valve piston surfaces through the pneumatic connections, the system reduces the force requirement on the linear motor without compromising pressure control capability.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If conventional proportional valves are used in compressed air systems, then system simplicity is maintained, but control precision for fast ABS and ASR is insufficient

Engineering Contradiction:
Improvesystem simplicityVSAvoidcontrol precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces conventional proportional valves with an electromechanical linear drive system that provides direct electrical control of the valve piston position. This substitution enables precise control for fast ABS and ASR applications while maintaining relative system simplicity through direct actuation without complex pneumatic control circuits.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The linear motor serves multiple functions: it provides precise positioning control for the valve piston, enables fast response for ABS and ASR, and can be controlled through simple electrical signals. This multi-functionality achieves high control precision without requiring separate control mechanisms.

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

4Adaptability or versatility

If valve pistons with large effective areas exposed to fluctuating pressures are used, then pressure control range is expanded, but non-linearity increases making current adjustment challenging

Engineering Contradiction:
Improvepressure control rangeVSAvoidcontrol linearity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements feedback through the second pneumatic connection that continuously equalizes pressure between the first and second pneumatic spaces. This feedback mechanism compensates for the non-linear effects of fluctuating pressures on the valve piston, maintaining control linearity across the full pressure control range.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent creates equipotential conditions by equalizing the pressure in the first and second pneumatic spaces through the second pneumatic connection. This eliminates pressure differences that would cause non-linear forces on the valve piston, resulting in more linear control characteristics across the operating range.

Inventive Principle:
Principle #12Equipotentiality

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, energy-efficient, and low-noise valve device capable of precise pressure control, reducing installation space and heat generation, while maintaining high flow capacity and durability, suitable for advanced braking systems like ABS and ASR.

Implementation Method 1

an electromechanical linear drive (41) which linearly drives the valve piston (12) for controlling pressures prevailing at the pressure medium outlet (46) as a function of an electrical control signal supplied to the linear drive (41)

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

using an electromagnet or linear actuator for precise pressure control

Methodology Applied
Scientific EffectElectromagnetism: Electromagnet

Data Source

PatentEP3218239B1Valve device for a compressed-air system, pressure control module having such a valve device, and motor vehicle equipped therewith
Publication Date: 2020.08.05 ZF CV SYST HANNOVER GMBH
  • EP3218239B1 patent drawingFigure 1
  • EP3218239B1 patent drawingFigure 2

AI summary

The invention relates to a valve device (2) for a compressed-air system, comprising a pressure-medium inlet (50) that can be connected to a pressure-medium source, at least one pressure-medium outlet (46) that can be connected to a consumer, and at least one vent (48) leading to the atmosphere. The valve device (2) also has a valve piston (12), which is movably arranged in a housing (4) and which moves an aeration piston (24) arranged separate from the valve piston (12) in order to open and close an inlet valve (38). The valve piston (12) is moved by means of an electromechanical linear drive (41), which linearly drives the valve piston (12) in accordance with an electrical control signal fed to the linear drive (41) in order to control pressures present at the pressure-medium outlet (46), e.g., brake pressures in a brake system. The invention further relates to a pressure control module for a compressed-air system of a motor vehicle having at least one valve device (2), and a motor vehicle, e.g., utility vehicle, having at least one valve device (2) and/or at least one pressure control module.