Outside Joint Member Forging for Precise Spline Teeth

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Solution Overview

Problem

Existing methods for manufacturing outside joint members in constant-velocity joints are time-consuming and require multiple steps, including separate shaping and heat treatment processes, which prolong the cycle time and increase costs.

Innovation Solution

A method involving simultaneous forging of the cup and spline shaft portions using a specialized forging die that shapes the spline teeth and regulates material displacement, allowing for warm forging and reducing the need for separate shaping and heat treatment steps, thereby shortening the manufacturing cycle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If separate shaping and heat treatment processes are used for the spline shaft, then manufacturing precision can be improved, but cycle time increases

Engineering Contradiction:

Improvespline teeth forming precisionVSAvoidmanufacturing cycle time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent combines the shaping of the spline shaft and heat treatment into a single integrated forging process. The forging die includes heating sections that directly heat and form the spline teeth in one operation, eliminating the need for separate shaping and heat treatment steps while maintaining manufacturing precision through controlled thermal-mechanical processing.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent performs preliminary heating of the forming material before forging. The heating sections preheat the material to optimal temperatures for plastic deformation, which improves formability and reduces the force required during forging, thereby enabling precise spline teeth formation while shortening the overall cycle time by preparing the material in advance.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If multiple separate manufacturing steps are used, then manufacturing precision can be maintained, but device complexity increases

Engineering Contradiction:

Improveoverall manufacturing precisionVSAvoidnumber of manufacturing steps

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges multiple manufacturing functions into a single integrated forging die. The die includes forming sections for the cup portion, shaft portion, and spline teeth, as well as heating sections positioned to heat specific areas during the forging process. This integration maintains precision by controlling each feature's formation in its optimal thermal state while reducing the number of separate devices and steps required.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The forging die performs multiple functions simultaneously: it shapes the cup portion, forms the shaft portion, creates spline teeth, and provides localized heating all in one operation. This multi-functional die design reduces device complexity by eliminating the need for separate shaping tools, heat treatment equipment, and multiple setup operations while maintaining comprehensive manufacturing precision.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If separate shaping of spline shaft is performed, then manufacturing flexibility is improved, but productivity decreases

Engineering Contradiction:

Improvemanufacturing flexibilityVSAvoidproduction efficiency

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent combines the shaping of all components (cup portion, shaft portion, and spline teeth) into a single forging operation using an integrated die. This merging of operations maintains manufacturing flexibility because the die can be designed to accommodate various geometries and the process can adapt to different material states through controlled heating, while simultaneously improving productivity by producing the entire component in one step rather than through multiple sequential operations.

Inventive Principle:

Principle #5Merging (Combining)

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 significantly reduces the cycle time, improves precision in forming spline teeth, and decreases the number of heating processes, leading to cost savings and enhanced processing efficiency.

Implementation Method 1

a heating step (S1) in which a forming material B to form the outside joint member 10 is heated

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 2

a forging step (S2) in which the forming material B that has been heated is forged

Methodology Applied

Scientific EffectPlastic deformation: Plasticity

Data Source

PatentUS11440084B2Method of manufacturing outside joint member

Publication Date: 2022.09.13 JTEKT CORP

AI summary

A method of manufacturing an outside joint member, the outside joint member including a cup portion in a bottomed tubular shape and a shaft portion that is a shaft-like portion extending from a bottom portion of the cup portion and that has a spline shaft having an outer peripheral surface on which spline teeth are formed, includes forging a forming material to form a shape of the cup portion and a shape of the spline shaft on the shaft portion simultaneously using a forging die.