Piezoelectric Three-Way Valve Actuator for High-Pressure Fuel Injection

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Solution Overview

Problem

Existing electrically or electromagnetically actuated control valves with three mouths and three operating positions face challenges in dynamic behavior control due to varying pressure environments, leading to increased actuator size and switching times, which are inadequate for high-speed response applications.

Innovation Solution

The valve design incorporates a piezoelectric or magnetostrictive actuator replacing the traditional solenoid actuator, allowing for adjustable motion of valve elements and reduced switching times by varying the actuation force, thereby minimizing the impact of pressure differences on the valve's moving elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If the electromagnet is sized to overcome maximum pressure forces, then the valve can operate under high pressure conditions, but the actuator dimensions and costs increase

Engineering Contradiction:
Improveoperating pressureVSAvoidactuator dimensions
Core Design Contradiction:
Stress or pressureVSVolume of moving object

Solution Approach 1:

The valve system is divided into two independent control valves instead of one valve with complex internal moving elements. Each valve handles a specific function (diverting flow to outlet 1 or outlet 2), simplifying the actuator requirements for each individual valve while maintaining overall system capability under high pressure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a variable stiffness mechanism that dynamically adjusts the mechanical feedback force based on operating conditions. This allows the actuator to overcome pressure forces only when necessary, reducing the required actuator size while maintaining high-pressure operation capability

Inventive Principle:
Principle #15Dynamics

2Stress or pressure

If the electromagnet is sized to overcome maximum pressure forces, then the valve can operate under high pressure conditions, but the switching times increase

Engineering Contradiction:
Improveoperating pressureVSAvoidswitching times
Core Design Contradiction:
Stress or pressureVSLoss of time

Solution Approach 1:

By separating the control functions into two independent valves with simpler actuators, each valve can switch faster than a single complex valve would require. The segmented architecture eliminates the need for oversized actuators, reducing switching times while maintaining high-pressure operation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The variable stiffness mechanism provides mechanical feedback that assists the actuator during switching, reducing the time required to overcome pressure forces. The dynamic adjustment of stiffness allows faster response during transient switching events

Inventive Principle:
Principle #15Dynamics

3Device complexity

If traditional solenoid actuator is used, then the valve structure is simple, but the response time is too slow for high-speed applications

Engineering Contradiction:
Improvevalve structureVSAvoidresponse time
Core Design Contradiction:
Device complexityVSSpeed

Solution Approach 1:

The variable stiffness mechanism with mechanical feedback dynamically adjusts the force characteristics during actuation, enabling faster response times compared to traditional solenoid actuators. This dynamic approach achieves high-speed response without significantly complicating the overall valve structure

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent replaces the purely electromagnetic solenoid actuation with a hybrid system that incorporates mechanical feedback elements. This substitution provides faster and more controllable response characteristics while maintaining structural simplicity

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

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

This design enables the valve to operate efficiently across different pressure environments with reduced actuator size and switching times, ensuring fast response times suitable for high-pressure applications, such as anti-lock braking systems and fuel injection systems.

Implementation Method 1

The control valve (1) is provided with an actuator member (AM) constituted by a stack of piezoelectric elements (PZ)

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

The valve design incorporates a piezoelectric or magnetostrictive actuator replacing the traditional solenoid actuator

Methodology Applied
Scientific EffectMagnetostriction: Magnetostriction

Data Source

PatentEP2806195B1Three-way three-position control valve having a piezoelectric or magnetostrictive actuator, and fuel injection system comprising this valve
Publication Date: 2015.10.28 CENTRO RICERCHE FIAT SCPA
  • EP2806195B1 patent drawingFigure 1A
  • EP2806195B1 patent drawingFigure 1B~1D
  • EP2806195B1 patent drawingFigure 2A~2B

AI summary

Described herein is an electrically actuated control valve (1) comprising three mouths (2, 4, 6) and three operating positions (P1, P2, P3), in which the three mouths (2, 4, 6) comprise: - a first mouth (2) for inlet of a working fluid, and - a second mouth (4) and a third mouth (6) for outlet of the working fluid, and wherein the three operating positions (P1, P2, P3) comprise: - a first operating position (P1) in which a passage of fluid from the first mouth (2) to the second mouth (4) and the third mouth (6) is enabled, - a second operating position (P2) in which a passage of fluid from the first mouth (2) to only one (6) of said second and third mouths (4, 6) is enabled, and - a third operating position (P3) in which the passage of fluid from the first (2) to the second mouth (4) and the third mouth (6) is disabled. The control valve (1) further comprises an electric or electromagnetic actuator (8), which can be controlled for causing a switching of the operating position (P1, P2, P3) and a moving element comprising a first valve element (12) and a second valve element (14) designed to co-operate, respectively, with a first valve seat (A1) and a second valve seat (A2) for controlling the passage of fluid from the first mouth to the second and third mouths providing the aforesaid three operating positions (P1, P2, P3). The electric actuator is of a type chosen between a piezoelectric actuator and a magnetostrictive actuator.