Brazed Spray Tip Assembly for Pre-Orifice Insert Alignment

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Solution Overview

Problem

Current spray tip assembly processes require outside diameter grinding of pre-orifice inserts, leading to significant scrap generation and alignment issues during assembly, which can affect the desired spray pattern.

Innovation Solution

A spray tip assembly process that eliminates OD grinding by using a slip fit with a filler metal in a brazing process to secure pre-orifice inserts within the stem, allowing for different internal geometries and secure attachment without the need for precise alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If outside diameter grinding is used to secure pre-orifice inserts, then secure attachment is achieved, but significant scrap generation and alignment issues occur

Engineering Contradiction:
Improveattachment strengthVSAvoidscrap generation
Core Design Contradiction:
StrengthVSLoss of substance

Solution Approach 1:

The patent replaces the mechanical outside diameter grinding system with a brazing process that uses filler metal to create a metallurgical bond between the pre-orifice insert and the spray tip stem. This substitution eliminates the need for abrasive grinding while achieving secure attachment through the brazing joint, thereby reducing scrap generation from the grinding process.

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

Solution Approach 2:

The invention changes the attachment mechanism from mechanical (grinding and press-fit) to thermal/metallurgical (brazing). By altering the bonding parameters from mechanical force to controlled thermal processing with filler metal, the process achieves secure attachment without the material removal and scrap associated with grinding operations.

Inventive Principle:
Principle #35Parameter changes

2Strength

If outside diameter grinding is used to secure pre-orifice inserts, then secure attachment is achieved, but alignment issues during assembly occur

Engineering Contradiction:
Improveattachment strengthVSAvoidalignment precision
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent replaces the mechanical alignment and grinding system with a brazing process that is less sensitive to alignment tolerances. The filler metal acts as a buffer that accommodates minor misalignments while creating a strong metallurgical bond, thereby eliminating alignment issues that plague mechanical press-fit assemblies requiring precise OD grinding.

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

Solution Approach 2:

The filler metal serves as an intermediary material between the pre-orifice insert and the spray tip stem. This intermediary layer compensates for dimensional variations and alignment discrepancies, allowing secure attachment without the need for precision alignment that would be required in a direct mechanical press-fit arrangement.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of substance

If outside diameter grinding is eliminated using slip fit with brazing, then scrap generation is reduced, but attachment security may be compromised

Engineering Contradiction:
Improvescrap generationVSAvoidattachment strength
Core Design Contradiction:
Loss of substanceVSStrength

Solution Approach 1:

The invention changes the bonding mechanism from mechanical interference fit to metallurgical brazing. By controlling the brazing parameters (temperature, filler metal composition, atmosphere), the process achieves attachment strength that meets or exceeds traditional mechanical methods while eliminating scrap generation from grinding operations.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite joint structure consisting of the pre-orifice insert, filler metal, and spray tip stem. This composite brazed joint combines the advantages of different materials and bonding mechanisms to achieve secure attachment without the need for grinding, thereby maintaining strength while reducing scrap.

Inventive Principle:
Principle #40Composite materials

4Manufacturing precision

If traditional assembly processes are used, then alignment precision can be achieved, but device complexity and manufacturing time increase

Engineering Contradiction:
Improvealignment precisionVSAvoidassembly process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces the complex multi-step mechanical assembly process (grinding, alignment, press-fit) with a simpler brazing process. The brazing operation inherently provides alignment tolerance and secure attachment in a single step, reducing overall process complexity while maintaining or improving alignment precision through the filler metal's compensating effect.

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 approach reduces scrap generation and ensures proper alignment of pre-orifice inserts, enhancing the consistency and quality of the spray pattern produced by the spray tip.

Implementation Method 1

A spray tip assembly process that eliminates OD grinding by using a slip fit with a filler metal in a brazing process to secure pre-orifice inserts within the stem

Methodology Applied
Scientific EffectBrazing: Brazing

Data Source

PatentEP3762149B1Spray tip design and manufacture
Publication Date: 2024.10.30 WAGNER SPRAY TECH CORP
  • EP3762149B1 patent drawingFigure 1
  • EP3762149B1 patent drawingFigure 2A~2B
  • EP3762149B1 patent drawingFigure 3A

AI summary

A spray tip (30) for a fluid applicator (10) includes a stem (450) configured to be inserted into the fluid applicator (10). The stem (450) includes a stem pre-orifice portion (444) and an insert receiving portion (306). The spray tip (30) includes a pre-orifice insert (442) having an inlet and an outlet. The pre-orifice insert (442) is disposed within the insert receiving portion (306) and disposed against a rearward shoulder (447) of the stem (450).