Hot-Press Tray Heating With Heat Storage for Thin Sheet Quenching

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In hot press-forming, materials with reduced thickness experience significant temperature drops during transportation to the press machine, leading to insufficient quenching and reduced strength of the press-formed product, as conventional methods like using a temperature-retaining cover or additional heating sources increase equipment size and costs.

Innovation Solution

A method involving a sheet-shaped heat storage member overlapping with the workpiece during heating and transportation, where they receive radiant heat from each other to maintain temperature, reducing heat transfer to the air and minimizing temperature loss, without the need for additional heat sources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a temperature-retaining cover or additional heating sources are used during transportation, then the temperature drop of the material is reduced, but the equipment size and manufacturing costs increase

Engineering Contradiction:

Improvematerial temperatureVSAvoidequipment size

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The material itself serves as the heat source for heating other materials. The first material, heated to a temperature higher than the melting point, radiates heat to the second material during transportation, eliminating the need for external heating devices or insulation covers.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The first material acts as an intermediary heat carrier between the heating device and the second material. Instead of using conventional insulation or heating sources, the system uses the thermal energy stored in the first material to maintain the temperature of the second material.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Temperature

If a temperature-retaining cover or additional heating sources are used during transportation, then the temperature drop of the material is reduced, but the operational costs increase

Engineering Contradiction:

Improvematerial temperatureVSAvoidoperational costs

Core Design Contradiction:

TemperatureVSUse of energy by stationary object

Solution Approach 1:

The system uses the thermal energy already stored in the first material to heat the second material, eliminating the need for continuous external energy input during transportation. This self-sustaining approach reduces operational energy costs.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The heat radiation from the first material to the second material continues throughout the transportation process, maintaining continuous heating without interruption or additional energy consumption, thereby reducing operational costs.

Inventive Principle:

Principle #20Continuity of useful action

3Productivity

If the material thickness is reduced, then the productivity and material efficiency are improved, but the temperature drop during transportation increases leading to insufficient quenching

Engineering Contradiction:

Improveproduction efficiencyVSAvoidmaterial temperature

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The first material serves as a portable heat source that compensates for the rapid heat loss characteristic of thin materials during transportation, enabling thin-gauge steel to maintain sufficient temperature for quenching without sacrificing productivity.

Inventive Principle:

Principle #25Self-service

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 reduces temperature drop during transportation, ensuring the material reaches the required quenching temperature for hot press-forming, thereby maintaining the strength of the press-formed product without increasing equipment size or operational costs.

Implementation Method 1

a primary heating means using dielectric heating and electrical heating, and a secondary heating means using radiant heat transmission

Methodology Applied

Scientific EffectRadiant heat transmission: Thermal Radiation

Implementation Method 2

they receive radiant heat from each other to maintain temperature

Methodology Applied

Scientific EffectRadiant heat: Thermal Radiation

Implementation Method 3

quenching is performed as the sheet is rapidly cooled by contact heat transfer to the die during press-forming

Methodology Applied

Scientific EffectContact heat transfer: Conduction (thermal)

Data Source

PatentUS20230330735A1Method of manufacturing press-formed product, and tray and hot-press manufacturing line used for manufacturing press-formed product

Publication Date: 2023.10.19 NIPPON STEEL CORPORATION

AI summary

A method of manufacturing a press-formed product includes a heating step, a transportation step, and a pressing step. At the heating step, a sheet-shaped heat storage member 5 and a sheet-shaped workpiece W1 placed above the heat storage member 5 are heated by a heating device 14 while overlapping in the direction normal to the sheet surfaces of the workpiece W1. At a first transportation sub-step, the heat storage member 5 and the workpiece W1 placed above the heat storage member 5 are transported from the heating device 14 to a lifting location while overlapping in the direction normal to the sheet surfaces of the workpiece W1. At a second transportation sub-step, the workpiece W1 placed above the heat storage member 5, when at the lifting location, is lifted upward by a transportation device 46 and transported to a pressing location on a press machine 20. At the pressing step, the workpiece W1 is processed by the press machine 20.