Turbocharger Bypass Valve Guided Toggle for Fine Initial Opening

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Solution Overview

Problem

Turbine bypass valves in turbochargers lack fine control during initial opening, leading to unsuitable transitions between two-stage and mono-stage modes, affecting engine performance and emissions control.

Innovation Solution

A bypass valve assembly with a guided toggle arrangement, featuring an articulated two-bar linkage and a non-linear, non-circular arc guide path, allows for precise control of the valve's opening phase while maintaining sealing capabilities and full-open angle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a typical turbine bypass valve design is used, then the valve can be fully closed or fully open (binary operation), but fine control during the initial opening phase cannot be achieved

Engineering Contradiction:
Improvefine control capabilityVSAvoidvalve mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by implementing a guided toggle mechanism that dynamically changes the relationship between actuator displacement and valve opening angle. The guide constrains the toggle linkage to follow a specific trajectory, creating a non-linear transmission ratio that provides fine control during initial opening while maintaining full travel capability. This dynamic mechanism allows the system to adapt its control characteristics throughout the operating range without requiring multiple valves or complex control systems.

Inventive Principle:
Principle #15Dynamics

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 smooth and controlled transitions between operating modes, enhancing engine performance and emissions management by allowing fine control over the initial opening phase of the bypass valve.

Implementation Method 1

The guided toggle arrangement comprises an articulated two-bar linkage comprising a first crank and a second crank each having a joint end and a connector end. The first and second cranks form a pivotal joint between the respective joint ends thereof, and the connector end of the first crank is fixedly connected to the valve stem

Methodology Applied
Scientific EffectMechanical linkage: Lever

Implementation Method 2

The actuator assembly is structured and arranged to advance the connector end of the second crank in one direction along a guide path lying in a plane perpendicular to the valve stem axis

Methodology Applied
Scientific EffectCam mechanism: Cam

Data Source

PatentEP4089269B1Turbocharger bypass valve and actuator assembly having guided toggle
Publication Date: 2025.01.08 GARRETT TRANSPORTATION I INC
  • EP4089269B1 patent drawingFigure 1
  • EP4089269B1 patent drawingFigure 2A~2B
  • EP4089269B1 patent drawingFigure 3A~3B

AI summary

A bypass valve assembly for a turbocharger includes a bypass valve (20) having a valve stem (24) rotatable about a valve stem axis (SA) for opening and closing the valve. The end of a first crank (C1) of an articulated two-bar linkage is connected to the valve stem. The end of a second crank (C2) of the linkage is connected to a cam follower (47) engaged with a guide cam (45,46). An actuator (42) provides motive force to the cam follower to proceed along the guide cam, which is configured to advance the cam follower along a guide path that is non-linear and non-circular arc, causing the two-bar linkage to rotate the valve stem. Valve stem angular displacement versus actuator stroke can be altered by modification of the shape of the guide path.