Spinning Forming with Opposed Induction Heating for Crack-Free Plates

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Solution Overview

Problem

Conventional spinning forming methods, particularly for titanium alloys, face challenges in achieving accurate shaping due to heat distribution issues and material cracking, as existing heating configurations either fail to provide adequate local heating or result in excessive heating of non-shaped portions, leading to deformations and cracks.

Innovation Solution

A spinning forming apparatus and method that utilize a high-frequency induction heating coil positioned opposite to the processing tool, allowing for local heating of the plate's circumference without direct contact with a shaping die, ensuring efficient and precise heating of the shaping target portion by using a receiving jig instead of a shaping die, and incorporating a control device to maintain optimal heating and shaping parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a burner is used to heat the plate extensively, then the plate can be heated uniformly, but non-shaped portions deform and already-shaped portions crack due to stress

Engineering Contradiction:
Improveplate temperatureVSAvoidshaping accuracy
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

The patent applies local quality by replacing extensive heating with localized heating. The heating device is positioned to heat only the specific region of the plate where the processing tool contacts it, rather than heating the entire plate. This localized approach maintains the necessary temperature for shaping the target portion while preventing thermal stress and deformation in non-shaped portions, thereby resolving the contradiction between achieving adequate temperature and maintaining shaping accuracy.

Inventive Principle:
Principle #3Local quality

2Temperature

If the heater is positioned between the processing tool and the plate, then local heating can be achieved, but the heater cannot be arranged at the most appropriate position and heating is insufficient

Engineering Contradiction:
Improveshaping target portion temperatureVSAvoidheater arrangement constraints
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent applies inversion by changing the heater position from between the processing tool and the plate to the opposite side of the plate. This allows the heater to be positioned at the most appropriate location for effective heating without being constrained by the processing tool's operational space. The heater can now be optimally positioned to directly heat the shaping target portion, improving thermal efficiency and eliminating the arrangement constraints that limited previous configurations.

Inventive Principle:
Principle #13The other way round (Inversion)

3Shape

If the shaping target portion contacts the mandrel, then the plate can be shaped along the mandrel shape, but heat is transferred to the mandrel and the plate temperature does not adequately increase

Engineering Contradiction:
Improveplate shapeVSAvoidplate temperature
Core Design Contradiction:
ShapeVSTemperature

Solution Approach 1:

The patent applies extraction by removing the mandrel from the shaping system. Instead of using a mandrel that the plate contacts and that absorbs heat, the invention uses a processing tool that contacts the heated plate to impart the desired shape. This extraction of the mandrel eliminates the heat sink effect, allowing the heating device to maintain adequate plate temperature without significant heat loss to the shaping die, while the shaping function is performed by the processing tool under controlled conditions.

Inventive Principle:
Principle #2Taking out (Extraction)

4Ease of manufacture

If cold spinning forming is applied to titanium alloy, then processing cost is reduced, but the material cracks due to high yield strength and low ductility

Engineering Contradiction:
Improveprocessing costVSAvoidmaterial integrity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies parameter changes by controlling the temperature parameter of the titanium alloy during processing. The heating device raises the temperature of the shaping target portion to a range where the material's yield strength decreases and ductility increases, enabling successful shaping without cracking. This temperature parameter change transforms the material properties temporarily during processing, allowing cost-effective spinning forming while maintaining material integrity that would otherwise be compromised in cold processing.

Inventive Principle:
Principle #35Parameter changes

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 enables accurate shaping of plates without deformations or cracks by ensuring appropriate heating of the target area, reducing material waste and processing costs, and improving the efficiency of the spinning forming process.

Implementation Method 1

a high frequency induction heating coil that is the heater is arranged from between a spatula that is the processing tool and a not-yet-shaped side portion of the plate toward a position where the processing tool and the plate contact each other

Methodology Applied
Scientific EffectHigh frequency induction heating: Induction Heating

Data Source

PatentEP2883629B1Spinning molding device and molding method
Publication Date: 2021.05.12 KAWASAKI JUKOGYO KK
  • EP2883629B1 patent drawingFigure 1
  • EP2883629B1 patent drawingFigure 2A~2B
  • EP2883629B1 patent drawingFigure 3

AI summary

A spinning forming apparatus (101) shapes a plate W while rotating the plate W around a rotational axis (S). The spinning forming apparatus (101) includes: a holding member (1) to which the plate (W) is attached and which rotates the plate (W) around the rotational axis (S); a processing tool (4) configured to contact a first main surface of the plate (W) to process and shape the plate (W); and a heater (5) configured to heat the plate (W). The heater (5) is arranged at the opposite side of the processing tool (4) across the plate (W). The heater (5) locally heats a position of a second main surface of the plate (W) opposite to the first main surface, the position being located on a circumference around the rotational axis (S), the circumference being defined by a position, with which the processing tool (4) contacts, of the plate (W).