Metal Box Arc Corner Drawing Process

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Solution Overview

Problem

Existing metal box manufacturing processes face challenges in creating corrugated grooves or convex strips on side surfaces, leading to complex moulds and difficult demoulding, especially at arc corner transition portions, resulting in high defective product rates.

Innovation Solution

A two-step drawing process using first and second metal drawing moulds to form convex strips on the top and side face plates of a rectangular metal shell, improving arc corner orderliness and stress capacity while simplifying demoulding and reducing defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If one-step drawing moulding is used to manufacture a box with corrugated grooves or convex strips on side surfaces, then the manufacturing process is simplified, but the mould becomes relatively complex and demoulding becomes very difficult

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidmould complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent divides the drawing process into two separate steps: first drawing the basic box shape, then separately forming the corrugated grooves or convex strips on the side surfaces. This segmentation allows each step to use simpler, specialized moulds rather than one complex mould attempting to do everything at once.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If one-step drawing moulding is used to manufacture a box with corrugated grooves or convex strips on side surfaces, then the manufacturing process is simplified, but demoulding becomes very difficult

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoiddemoulding ease
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

By separating the drawing process into two steps, the patent ensures that the first drawing creates a smooth basic shape that demoulds easily, while the second drawing adds surface features after demoulding. This avoids the demoulding difficulties that would arise from trying to form complex surface features during the initial drawing when the material is most constrained.

Inventive Principle:
Principle #1Segmentation

3Strength

If drawing is performed at arc corner transition portions to form convex strips, then the box has attractive appearance and improved structure, but the possibility of mould clamping increases and defective products are produced

Engineering Contradiction:
Improvearc corner stress capacityVSAvoiddefective product rate
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent performs the first drawing to create the basic box shape with arc corners before attempting to form convex strips. This preliminary action prepares the material in a more favorable state for the second drawing, reducing the risk of mould clamping and defects when forming the convex strips at the arc corners.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

By dividing the formation of arc corner features into two separate drawing steps, the patent reduces the complexity and stress concentration in any single drawing operation, thereby reducing the likelihood of mould clamping and defective products while still achieving the desired arc corner strength and appearance.

Inventive Principle:
Principle #1Segmentation

4Strength

If corrugated grooves or convex strips are formed on side surfaces through one-step drawing, then the box has improved appearance and structure, but the mould becomes relatively complex

Engineering Contradiction:
Improveside surface structural strengthVSAvoidmould complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent separates the formation of side surface corrugated grooves or convex strips into a second drawing step performed after the basic box shape is formed. This allows the use of simpler, specialized moulds for each step rather than one complex mould that would be needed to form both the basic shape and surface features simultaneously.

Inventive Principle:
Principle #1Segmentation

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

The process enhances the attractiveness and durability of metal box shells by forming convex grains at arc corners, facilitates demoulding, and reduces defective products through improved stress capacity and simplified production.

Implementation Method 1

drawing by means of a first metal drawing mould a top face plate of the rectangular metal shell for the first time, so that a plurality of first convex strips are formed

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP3266532B1Drawing process for arc corner connecting rib of metal box casing
Publication Date: 2020.08.26 FEI XIAOMING
  • EP3266532B1 patent drawingFigure 1~2
  • EP3266532B1 patent drawingFigure 3~4

AI summary

The present invention discloses a drawing process of an arc corner connecting rib of a metal box shell. The drawing process comprises the following steps: preparing a rectangular metal shell whose vertex corner portions are arc corner transition portions; drawing by means of a first metal drawing mould a top face plate of the rectangular metal shell for the first time, so that a plurality of first convex strips are formed in a first area between the two arc corner transition portions of the top face plate; and drawing by means of a second metal drawing mould a side face plate and the arc corner transition portions of the rectangular metal shell obtained after the first drawing moulding for the second time, so that a plurality of second convex strips are formed in a second area between the two arc corner transition portions of the side face plate. The drawing process has beneficial effects that through two times of drawing, the arc corners can be orderly, and a stress capacity of the arc corners is improved; meanwhile, convex grain can be formed on the shell, especially at the arc corners, so that the shell is attractive and durable; especially, demoulding is facilitated in the whole manufacturing process, the production process is simplified, and the occurrence rate of defective products is reduced.