Hot Coiling Machine Mandrel-Free Wire Forming

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Solution Overview

Problem

Conventional hot coiling machines require mandrels for producing coil springs with different diameters and shapes, leading to inefficient working and heat loss due to multiple roll contacts during wire transfer.

Innovation Solution

A hot coiling machine design that minimizes mandrel use by employing a center roll and feeding roll for wire transfer, with a pitch control unit and forming rolls positioned on the same plane to adjust coil pitch and diameter, and a bending actuator to guide the wire into a smooth coil shape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a mandrel is used to produce coil springs with different diameters and shapes, then the coil spring production is enabled, but the working efficiency deteriorates due to the need to prepare and select various types of mandrels

Engineering Contradiction:
Improveability to produce coil springs with different diameters and shapesVSAvoidworking efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent removes the mandrel from the coiling system entirely. Instead of using a mandrel to define the coil shape, the invention uses a series of rolls (feeding roll, center roll, and forming rolls) that guide and form the heated wire directly into coil springs of various diameters and shapes through their arrangement and movement, eliminating the need to prepare and select different mandrels for different spring specifications

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The forming rolls are designed to perform multiple functions: they guide the wire, define the coil diameter through their positioning, and control the coiling process. By adjusting the position and configuration of the forming rolls, the same set of rolls can produce coil springs with different diameters and shapes, making the system universal rather than requiring specialized mandrels for each spring type

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of operation

If multiple rolls are used to transfer the wire to the forming rolls, then the wire transfer is enabled, but heat loss increases due to multiple contacts between rolls and wire

Engineering Contradiction:
Improvewire transfer capabilityVSAvoidheat loss of wire
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent minimizes the number of roll contacts the wire must undergo during transfer. The feeding roll and center roll are positioned and configured to transfer the wire efficiently with minimal contact points, allowing the heated wire to pass through the transfer zone quickly before entering the forming rolls, thereby reducing the time for heat loss to occur

Inventive Principle:
Principle #21Skipping (Rushing through)

Solution Approach 2:

The invention positions the feeding roll, center roll, and forming rolls in a specific spatial arrangement where the wire transfer path is optimized. The rolls are positioned on the same plane and arranged to create a direct transfer path that reduces the number of contact points and minimizes the distance the wire travels through the rolling contacts, thereby reducing heat loss

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Manufacturing precision

If the wire is transferred through multiple rolls, then the wire positioning is improved, but the wire temperature decreases due to heat loss during transfer

Engineering Contradiction:
Improvewire positioning accuracyVSAvoidwire temperature
Core Design Contradiction:
Manufacturing precisionVSTemperature

Solution Approach 1:

The patent ensures that the wire transfer process is continuous and efficient, with the feeding roll, center roll, and forming rolls operating in a coordinated manner. The wire is transferred smoothly without interruptions or excessive handling, maintaining its temperature by minimizing the time spent in the transfer zone while still achieving proper positioning for coiling

Inventive Principle:
Principle #20Continuity of useful 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

Enables the production of various coil shapes and diameters with reduced heat loss and damage, allowing for precise pitch control and efficient coil spring formation without mandrels.

Implementation Method 1

the cut wire is heated to a predetermined temperature and coiled

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

the transferred wire is deformed into a coil shape by means of a forming roll

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 3

a lateral surface of the coiled wire exiting the forming roll is pushed by a separate roller so as to provide the coiled wire with a desired pitch

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP3127629B1Device for manufacturing hot-rolled coil spring
Publication Date: 2020.05.06 DAEWON KANG UP CO LTD
  • EP3127629B1 patent drawingFigure 1~2
  • EP3127629B1 patent drawingFigure 3
  • EP3127629B1 patent drawingFigure 4

AI summary

The present invention relates to a hot coiling machine, and an object of the invention is to provide a hot coiling machine that produces coil springs having various coil shapes and diameters from a heated wire without a mandrel. The present invention provides a hot coiling machine including: a center roll rotating by a drive unit; a feeding roll disposed near the center roll and facing an external surface of the center roll, the center roll being configured to move by a first positioning unit and being rotated by a drive unit thus moving a wire together with the center roll; a forming roll for forming the wire into a coil shape; and a pitch control unit disposed near the forming roll to come into contact with the coiled wire and pushing the coiled wire to provide the coiled wire with a desired pitch.