Valve Latching Mechanism for Power Failure Position Stability

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Solution Overview

Problem

Electromagnetically controllable valves in safety-critical applications face reliability issues due to potential unwanted changes in switching position during electrical faults or power failures, posing safety risks.

Innovation Solution

A valve design featuring a magnetic separation point between the actuating magnet's armature and adapter, with a latching device and sealing ring, ensures the control slide remains in a defined position even during power failures, utilizing a combination of 'pushing' and 'pulling' magnets and a locking mechanism with spring-loaded detent balls to maintain position stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If an electromagnetically controllable valve is used in safety-critical applications, then the valve can be controlled remotely and quickly, but the valve may change switching position unintentionally during electrical faults or power failures

Engineering Contradiction:
Improveresponse speedVSAvoidswitching position stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The latching device is pre-configured with detent balls and locking notches that automatically engage to hold the control slide in its current position. This preliminary mechanical locking arrangement ensures that when electrical power is lost or a fault occurs, the valve maintains its last valid switching position without requiring active power to maintain position, thus preventing unintended position changes during electrical faults

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces the purely electromagnetic holding mechanism with a mechanical latching system. The detent balls and locking notches create a mechanical memory function that substitutes for continuous electrical power, allowing the valve to maintain its switching position through mechanical means rather than requiring continuous electromagnetic force, thereby improving reliability during power failures

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

2Reliability

If a latching device is added to hold the control slide in position during power failures, then safety is improved, but the device complexity increases

Engineering Contradiction:
ImprovesafetyVSAvoidvalve structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The latching device is integrated into the existing valve body structure, combining the locking function with the valve housing rather than adding a separate external mechanism. The detent balls are housed within recesses in the valve body, and the locking notches are formed directly on the control slide or valve components, merging multiple functions into a unified structure that minimizes additional complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The latching device operates automatically without requiring external control or additional components. The spring-loaded detent balls automatically engage with the locking notches when the control slide reaches a terminal position, and the mechanism self-actuates through the normal valve operation movements, eliminating the need for separate actuators or control systems

Inventive Principle:
Principle #25Self-service

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 enhances operational reliability by preventing unsafe changes in valve state during electrical faults, ensuring safety in applications like gear shifting and pilot control, and can be retrofitted for existing valves to improve overall hydraulic circuit safety.

Implementation Method 1

electromagnetic actuation of valves that can be set in defined valve positions

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Implementation Method 2

actuating magnet has two separately energizable coils arranged next to one another in the axial direction of the associated armature, which, when energized, enable the movement of the armature

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

locking device with spring-loaded detent balls to maintain position stability

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP3067572B1Valve
Publication Date: 2017.10.04 HYDAC FLUITECHNIK GMBH
  • EP3067572B1 patent drawingFigure 1~3
  • EP3067572B1 patent drawingFigure 2

AI summary

2. A valve with a control spool (22) which is longitudinally movable in a valve housing (24) and which selectively connects or separates several fluid connection points (P, A, B, T) in the valve housing (24) in a fluid-carrying manner, and which can be actuated by means of at least one actuating magnet (2), is characterized in that a detent device (48, 54, 56) is provided such that, in the event of failure of the actuating magnet (2), the control spool (22) is held in a defined position.