Press Line Split-Die Forming for Standing Wall Tolerance

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Solution Overview

Problem

The existing press-formed article manufacturing method is sensitive to the protruding amount of the punch-side pad, leading to a narrow tolerance range for the standing wall dimension and increased complexity and cost due to the use of pads in both the punch and die, which complicates the pressing apparatus and increases facility restrictions.

Innovation Solution

A press line with a tandem press line configuration using a series of pressing apparatuses connected by conveying devices, where the second pressing apparatus employs a split die to adjust the protruding amount of a convex portion from the punch, allowing for a wider tolerance range and simplifying the apparatus structure by eliminating the need for pads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the protruding amount of the punch-side pad is increased to suppress springback, then the springback is reduced, but the standing wall dimension becomes highly sensitive to protruding amount changes and the tolerance range narrows

Engineering Contradiction:
Improvespringback suppressionVSAvoidstanding wall dimension tolerance
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The invention extracts and eliminates the punch-side pad from the pressing apparatus. By removing this component that causes the technical contradiction, the patent achieves springback suppression through alternative means (punch shape design and pressing force control) without the harmful sensitivity to protruding amount adjustments.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the controlling parameters from pad protruding amount to punch shape geometry and pressing force magnitude. This parameter transformation allows springback control while maintaining dimensional stability and expanding the effective tolerance range for standing wall dimensions.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If pads are included in both the punch and die to form the press-formed article, then the springback is suppressed, but the apparatus structure becomes complicated and manufacturing cost increases

Engineering Contradiction:
Improvespringback suppressionVSAvoidpressing apparatus structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the punch-side pad component from the pressing apparatus. This removal simplifies the apparatus structure, reduces manufacturing cost, and maintains springback suppression capability through alternative design approaches using the punch geometry and pressing force control.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The punch structure is designed to perform multiple functions: forming the standing wall, controlling springback through its geometry, and eliminating the need for a separate pad component. This multi-functionality reduces the overall number of components and simplifies the apparatus.

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

3Manufacturing precision

If the protruding amount of the punch-side pad is accurately adjusted to maintain standing wall dimension within tolerance, then the manufacturing precision is improved, but the productivity decreases due to complex adjustment requirements

Engineering Contradiction:
Improvestanding wall dimension accuracyVSAvoidproduction efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

By removing the adjustable pad component, the invention eliminates the complex adjustment mechanism and associated productivity losses. The fixed punch structure requires no adjustment while maintaining dimensional accuracy through its geometric design.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The punch structure is designed to automatically maintain the standing wall dimension within tolerance through its inherent geometry and the pressing force applied, without requiring external adjustment mechanisms or operator intervention for calibration.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3636362B1Press-molded article manufacturing method and press line
Publication Date: 2024.11.27 NIPPON STEEL CORPORATION
  • EP3636362B1 patent drawingFigure 1
  • EP3636362B1 patent drawingFigure 2
  • EP3636362B1 patent drawingFigure 3

AI summary

Provided is a press-formed article manufacturing method including a first step of pressing a blank with the first pressing apparatus to form a first intermediate formed article having a pair of bent portions that is bent to one side in the plate thickness direction and having a spacing between the bent portions that is narrower than the width of the top plate and equal to or more than the width of the top portion of the convex portion, and a second step of moving the second die relative to the second punch side punch with respect to the die pad and the second punch and forming a second intermediate formed article, having the standing wall formed therein, with the second die and the second punch, in a state where a portion between the bent portions is sandwiched between the die pad protruding from the second die to the second punch side punch, and the convex portion, with one side of the first intermediate formed article in the plate thickness direction as the convex portion side of the second pressing apparatus.