Piston Production via Pre-Shaped Forging and Welding

Solution Overview

Problem

The existing method for producing pistons for internal combustion engines is time-consuming and costly due to the need for extensive cutting machining processes on both the upper and lower piston parts after separation.

Innovation Solution

The method involves pre-shaping the piston blank during forging to match the upper and lower parts, introducing pin bores, and finish-machining the lower part before welding, reducing the need for extensive cutting on both parts and simplifying the production process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If both upper and lower piston parts are extensively machined after separation, then manufacturing precision is achieved, but production time and costs increase significantly

Engineering Contradiction:

Improvepiston part precisionVSAvoidproduction time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The piston blank is pre-shaped during the forging process to closely match the final geometry of both upper and lower piston parts. This preliminary forming reduces the amount of material removal needed later, significantly decreasing machining time while maintaining precision requirements. The blank is prepared in advance with near-net shape dimensions before separation into upper and lower parts.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The piston production is divided into distinct stages: forging the blank with pre-shaping, separating into upper and lower parts, and then performing minimal finish machining only where necessary. This segmentation allows the bulk of material removal to be avoided by doing the work during forging, while post-separation machining is limited to precision finishing operations.

Inventive Principle:

Principle #1Segmentation

2Manufacturing precision

If both upper and lower piston parts undergo extensive cutting machining, then required precision is achieved, but production costs increase

Engineering Contradiction:

Improvepiston part precisionVSAvoidproduction cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The piston blank is pre-shaped during the forging process to closely match the final geometry of both upper and lower piston parts. This preliminary forming reduces the amount of material removal needed later, significantly decreasing machining time while maintaining precision requirements. The blank is prepared in advance with near-net shape dimensions before separation into upper and lower parts.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The piston production is divided into distinct stages: forging the blank with pre-shaping, separating into upper and lower parts, and then performing minimal finish machining only where necessary. This segmentation allows the bulk of material removal to be avoided by doing the work during forging, while post-separation machining is limited to precision finishing operations.

Inventive Principle:

Principle #1Segmentation

3Manufacturing precision

If the piston blank is extensively machined after forging, then the required geometric precision is achieved, but the complexity of the production process increases

Engineering Contradiction:

Improvegeometric precisionVSAvoidproduction process complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The piston blank is pre-shaped during the forging process to closely match the final geometry of both upper and lower piston parts. This preliminary forming reduces the amount of material removal needed later, significantly decreasing machining time while maintaining precision requirements. The blank is prepared in advance with near-net shape dimensions before separation into upper and lower parts.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The piston production is divided into distinct stages: forging the blank with pre-shaping, separating into upper and lower parts, and then performing minimal finish machining only where necessary. This segmentation allows the bulk of material removal to be avoided by doing the work during forging, while post-separation machining is limited to precision finishing operations.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS8631572B2Method for the production of a piston for an internal combustion engine

Publication Date: 2014.01.21 MAHLE INT GMBH

AI summary

A method for the production of a piston for an internal combustion engine, in which a piston blank is forged, which is subsequently separated into two parts, to form an upper piston part and a lower piston part, after which the lower piston part and the upper piston part are machined and then welded to one another. Subsequently, the piston is finished. During forging of the piston blank, the top of the piston blank is partly given the shape of the underside of the upper piston part, and the underside of the piston blank is given the shape that corresponds to the interior of the lower piston part. After forging of the piston blank and before separation of the upper piston part from the lower piston part, the top of the piston blank is given the finished shape of the underside of the upper piston part by a cutting machining method.