Dosing Valve Calibration Body Connection for Freezing Resistance

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Solution Overview

Problem

Existing metering valves for urea-water solutions in exhaust gas treatment systems are prone to freezing, which can cause structural damage and operational failures due to the expansion of frozen additives, and require expensive designs to withstand freezing temperatures.

Innovation Solution

A metering valve design featuring a valve housing with a movable valve body, a spring for maintaining a rest position, and a calibration body secured via both a press connection and a material connection, such as a welded or soldered joint, to ensure consistent spring force and prevent deformation under ice pressure, combined with a drive unit for precise control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the metering valve uses a press connection to secure the calibration body, then the assembly is simple and cost-effective, but the connection deforms under ice pressure when the additive freezes

Engineering Contradiction:
Improveassembly simplicityVSAvoidconnection stability under freezing
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The calibration body is inserted into the valve housing with a press connection before the additive can freeze. This preliminary assembly allows the components to be easily manufactured and assembled, while the subsequent material connection prevents deformation when freezing occurs during operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The connection between the calibration body and valve housing combines two different connection methods: a press connection (mechanical fit) and a material connection (welding or soldering). This composite connection approach provides both ease of assembly and resistance to deformation under ice pressure.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the metering valve is designed to withstand freezing temperatures, then it resists damage from frozen additives, but the cost of the valve increases

Engineering Contradiction:
Improvefreezing resistanceVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The metering valve is divided into separate components (valve housing, calibration body, valve body) that can be manufactured using standard, cost-effective processes. The freezing resistance is achieved through the connection method between components rather than requiring the entire valve to be made from expensive freeze-resistant materials.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The combination of press connection and material connection creates a composite structural system that provides freezing resistance. This allows the use of conventional, cost-effective materials and manufacturing processes while achieving the required durability against freezing damage.

Inventive Principle:
Principle #40Composite materials

3Manufacturing precision

If the calibration body is securely connected to prevent deformation, then consistent spring force is maintained, but the connection method becomes more complex

Engineering Contradiction:
Improvespring force consistencyVSAvoidconnection method complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The calibration body is preliminarily positioned using a press connection that allows for precise adjustment of the spring force. Once the correct position is achieved, a material connection is created to lock it in place. This preliminary positioning step enables manufacturing precision without requiring complex connection mechanisms from the start.

Inventive Principle:
Principle #10Preliminary action

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 design effectively prevents permanent deformation and ensures consistent performance by distributing forces between connections, maintaining the metering valve's functionality and cost-effectiveness even under freezing conditions.

Implementation Method 1

a spring which exerts a spring force on the valve body and thus holds the valve body in a rest position

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

a calibration body secured via both a press connection and a material connection, such as a welded or soldered joint

Methodology Applied
Scientific EffectWelding: Welding

Implementation Method 3

a calibration body secured via both a press connection and a material connection, such as a welded or soldered joint

Methodology Applied
Scientific EffectSoldering: Soldering

Implementation Method 4

the additive freezes, which can cause structural damage and operational failures due to the expansion of frozen additives

Methodology Applied
Scientific EffectFreezing: Freezing

Implementation Method 5

the expansion of frozen additives

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP2809897B1Dosing valve for additives at risk of freezing
Publication Date: 2018.10.31 CONTINENTAL AUTOMOTIVE GMBH
  • EP2809897B1 patent drawingFigure 1~2
  • EP2809897B1 patent drawingFigure 3~4
  • EP2809897B1 patent drawingFigure 5~6

AI summary

The invention relates to a dosing valve (1), at least having a valve housing (6) with a duct (7) and having a valve body (2) which is movable in order to open and close the dosing valve (1) and having a spring (3) which exerts a spring force on the valve body (2) and thus holds the valve body (2) in a rest position, wherein the spring (3) is supported on at least one calibration body (4), the valve body (2), the spring (3) and the at least one calibration body (4) are arranged in the duct (7), and the at least one calibration body (4) is fastened in the valve housing (6) at least by means of a cohesive connection (5).