Lost Pattern Assembly Using Gauge to Prevent Glue Beads

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Solution Overview

Problem

The existing methods for assembling lost models in foundry molding, particularly for complex shapes like engine cylinder heads, often result in the formation of glue beads at interface zones between strata, which can alter the shape and hinder the insertion of components or fluid circulation due to geometric modifications.

Innovation Solution

A method involving the use of a gauge inserted into the cavity of the lower stratum before assembly, which is sized to fill the cavity and prevents glue accumulation, combined with a non-stick silicone sleeve and actuator for precise positioning and easy removal, ensuring a bead-free interface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If strata are assembled by gluing without a gauge, then the assembly process is simple and quick, but glue beads form in the cavity interfaces between strata

Engineering Contradiction:
Improveassembly process simplicityVSAvoidcavity geometry accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

A gauge is inserted into the cavity portion of the lower stratum before the upper stratum is glued onto it. This preliminary placement of the gauge prevents glue from entering the cavity during the assembly process, thereby eliminating glue beads while maintaining assembly simplicity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The gauge acts as an intermediary object that temporarily occupies the cavity space during assembly. It mediates between the gluing process and the cavity, preventing direct contact between glue and cavity while allowing the strata to be bonded effectively

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If glue is applied generously to ensure strong bonding, then bonding strength increases, but glue beads accumulate in the cavity

Engineering Contradiction:
Improvebonding strength between strataVSAvoidcavity shape accuracy
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The gauge serves as a physical barrier that prevents glue from entering the cavity while allowing adequate glue to be applied for strong bonding. The gauge mediates between the need for strong adhesion and the need to maintain precise cavity geometry

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

By placing the gauge before applying glue, the system prepares the cavity space in advance to receive and contain the glue outside the cavity, ensuring both strong bonding and precise cavity shape

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If the cavity geometry is modified by glue beads, then the component insertion becomes difficult, but removing the gauge adds an extra step

Engineering Contradiction:
Improvecomponent insertion easeVSAvoidassembly process complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The gauge is removed after the glue has effectively bonded the strata together. This timing ensures that the cavity geometry is preserved without glue beads, making component insertion easy, while the gauge itself is simple enough that its temporary presence does not significantly complicate the assembly process

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

This approach effectively minimizes and eliminates glue beads at the interface between strata, maintaining the desired geometry and dimensions of the casting, ensuring accurate component fitment and unobstructed fluid circulation.

Implementation Method 1

In contact with the molten metallic material, the sublimable material is sublimated to give way to the metallic material

Methodology Applied
Scientific EffectSublimation: Sublimation

Implementation Method 2

The lower face 14a of the upper stratum 14 is glued then laid on the upper face of the lower stratum 13

Methodology Applied
Scientific EffectAdhesive bonding: Adhesive

Data Source

PatentEP2949409B1Method for producing a lost pattern for use in foundry
Publication Date: 2018.09.12 PSA AUTOMOBILES SA
  • EP2949409B1 patent drawingFigure 1~5
  • EP2949409B1 patent drawingFigure 6~8c

AI summary

The invention relates to a method for making a lost model comprising a stack of layers, such that the lost model includes a cavity opening (16') through an opening to the outside of the model and which is jointly defined by two portions of cavity belonging respectively to two successive layers (13, 14), respectively called lower layer (13) and upper layer (14) in the stack, the method comprising the following successive steps: - a gauge (18) is inserted into the portion of cavity belonging to the lower layer (13) before assembly of the latter, the gauge being dimensioned to fill the majority of the complete cavity, - the lower face of the upper layer (14) intended to be assembled to the lower layer is glued,- The upper layer (14) is placed on the lower layer (13) so as to complete the cavity portion of the lower layer (13) with the cavity portion belonging to the following layer (13) to constitute the cavity, - the template (18) is removed after the two successive layers (13,14) have effectively bonded together.