Pilot Valve Arrangement for Compact Fluid Control

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Solution Overview

Problem

Conventional valve arrangements for automatic transmissions with start/stop functions require large, expensive magnet systems due to high volume flows, making them unsuitable for compact and cost-effective implementation.

Innovation Solution

A compact valve arrangement using a small, inexpensive electromagnetic seat valve as a pilot valve, integrated within the accumulator, which utilizes a control piston and check valve configuration to manage fluid flow efficiently, eliminating the need for an additional pressure source and allowing for precise control of fluid release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a directly controlled seat valve is used to handle high volume flows, then the flow capacity is sufficient, but the magnet system becomes large and expensive

Engineering Contradiction:
Improvevolume flowVSAvoidmagnet system size
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent introduces a pilot valve as an intermediary control element that manages a small control volume flow to regulate a much larger main volume flow. The pilot valve's control piston receives a small fluid quantity from the accumulator, which then controls the check valve to release the larger stored fluid volume. This mediator approach allows precise control without requiring a large magnet system capable of handling the full flow volume.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The accumulator serves a dual function: it stores the large volume of fluid needed for start/stop operation and simultaneously provides the control volume flow to the pilot valve. The system uses its own stored resources (the control volume within the accumulator) to actuate the valve, eliminating the need for external control pressure sources and reducing overall system complexity.

Inventive Principle:
Principle #25Self-service

2Quantity of substance

If a directly controlled seat valve is used for high volume flows, then the flow requirement is met, but the valve arrangement becomes large and costly

Engineering Contradiction:
Improvevolume flowVSAvoidvalve arrangement size
Core Design Contradiction:
Quantity of substanceVSVolume of moving object

Solution Approach 1:

The pilot valve acts as a mediator that translates a small control signal into a large flow response. By controlling the check valve through a small control volume from the accumulator, the system achieves large volume flow capability with a compact valve arrangement. The pilot valve's small size contrasts with the large flow capacity it enables through the check valve mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If a pilot valve with small control volume is used, then the valve arrangement becomes compact and cost-effective, but control of high volume flow must be achieved indirectly

Engineering Contradiction:
Improvevalve arrangement simplicityVSAvoidcontrol mechanism complexity
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The invention extracts the control function from the main flow path by separating the pilot valve (handling small control volume) from the check valve (handling large main volume). This extraction allows each valve to be optimized for its specific flow range, with the pilot valve providing compact control and the check valve providing high-capacity flow management, reducing overall system complexity despite the indirect control mechanism.

Inventive Principle:
Principle #2Taking out (Extraction)

4Volume of moving object

If integrated parts in accumulator are used, then compactness is achieved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvevalve arrangement compactnessVSAvoidintegration precision
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The patent merges the valve arrangement components (pilot valve, check valve, control piston) with the accumulator by integrating them into the base plate. This consolidation achieves compactness by eliminating separate mounting structures and reducing overall system volume. The integration into a single base plate structure simplifies assembly while maintaining functional separation of the valve components.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables a compact, cost-effective valve arrangement that can handle high volume flows without the need for a large magnet system, providing efficient and reliable fluid management for automatic transmissions.

Implementation Method 1

a very small and therefore inexpensive electromagnetic seat valve, preferably a microvalve, can be used as a pilot valve

Methodology Applied
Scientific EffectElectromagnetic force: Electromagnet

Implementation Method 2

the smaller amount of fluid flows through the seat valve. It has also been recognized that the required control volume flow can be taken from the memory itself

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 3

A needle could be accommodated in the main piston, which abuts against a spring-loaded ball of the check valve

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP2565468B1Valve assembly
Publication Date: 2015.07.29 CARL FREUDENBERG KG
  • EP2565468B1 patent drawingFigure 1
  • EP2565468B1 patent drawingFigure 2
  • EP2565468B1 patent drawingFigure 3

AI summary

The valve array has reservoir (1) containing a pressurized fluid, a non-return valve (3), and a seat valve (2) that is actuatable so as to allow the fluid to flow out of the reservoir. The seat valve is configured as a pilot control valve connected to the reservoir such that in an open condition of the seat valve a smaller amount of the fluid flows out of the reservoir via the seat valve and a larger amount of the fluid flows out of the reservoir via the non-return valve.