Multipart Punch for Hydro Piercing Apertures

Solution Overview

Problem

Conventional stepped punch systems require high pressures and calibration pressures to form large apertures in hydroformed metal members, leading to increased tooling costs and longer cycle times, and hinder the feeding of additional blank during hydroforming.

Innovation Solution

A multipart punch system comprising a first punch segment, a second punch segment, and a ram, where the ram moves the first punch segment to pierce the hydroformed member before moving the second punch segment, allowing for the formation of apertures with two or more smaller slugs that can be held captive or removed, and providing a flush surface for easy mold loading and unloading.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a stepped punch is used to form large apertures, then the aperture can be formed with two smaller slugs, but very high punch pressures and calibration pressures are required

Engineering Contradiction:

Improveaperture formationVSAvoidpunch pressure

Core Design Contradiction:

Manufacturing precisionVSStress or pressure

Solution Approach 1:

The punch is divided into two separate punch segments that can move independently relative to each other. The first punch segment forms the first aperture, and the second punch segment forms the second aperture. This segmentation allows each segment to operate with lower pressure requirements compared to a single stepped punch, while still achieving the desired aperture formation with slugs that can be held captive.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The punch segments are designed with dynamic movement capabilities, where the first punch segment can extend beyond the initial position of the second punch segment during the punching operation. This dynamic arrangement allows the punch segments to move at different rates and positions, enabling aperture formation without requiring the very high pressures needed by static stepped punch systems.

Inventive Principle:

Principle #15Dynamics

2Manufacturing precision

If a stepped punch is used to form large apertures, then the aperture can be formed with two smaller slugs, but the tooling and rams become expensive

Engineering Contradiction:

Improveaperture formationVSAvoidtooling cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The punch is divided into two separate punch segments that can move independently relative to each other. The first punch segment forms the first aperture, and the second punch segment forms the second aperture. This segmentation allows each segment to operate with lower pressure requirements compared to a single stepped punch, while still achieving the desired aperture formation with slugs that can be held captive.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The punch segments are designed with dynamic movement capabilities, where the first punch segment can extend beyond the initial position of the second punch segment during the punching operation. This dynamic arrangement allows the punch segments to move at different rates and positions, enabling aperture formation without requiring the very high pressures needed by static stepped punch systems.

Inventive Principle:

Principle #15Dynamics

3Manufacturing precision

If a stepped punch is used to form large apertures, then the aperture can be formed with two smaller slugs, but the cycle times increase

Engineering Contradiction:

Improveaperture formationVSAvoidcycle time

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The punch is divided into two separate punch segments that can move independently relative to each other. The first punch segment forms the first aperture, and the second punch segment forms the second aperture. This segmentation allows each segment to operate with lower pressure requirements compared to a single stepped punch, while still achieving the desired aperture formation with slugs that can be held captive.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The punch segments are designed with dynamic movement capabilities, where the first punch segment can extend beyond the initial position of the second punch segment during the punching operation. This dynamic arrangement allows the punch segments to move at different rates and positions, enabling aperture formation without requiring the very high pressures needed by static stepped punch systems.

Inventive Principle:

Principle #15Dynamics

4Manufacturing precision

If a stepped punch is used to form large apertures, then the aperture can be formed with two smaller slugs, but additional blank feeding is prevented

Engineering Contradiction:

Improveaperture formationVSAvoidblank feeding capability

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The punch is divided into two separate punch segments that can move independently relative to each other. The first punch segment forms the first aperture, and the second punch segment forms the second aperture. This segmentation allows each segment to operate with lower pressure requirements compared to a single stepped punch, while still achieving the desired aperture formation with slugs that can be held captive.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The punch segments are designed with dynamic movement capabilities, where the first punch segment can extend beyond the initial position of the second punch segment during the punching operation. This dynamic arrangement allows the punch segments to move at different rates and positions, enabling aperture formation without requiring the very high pressures needed by static stepped punch systems.

Inventive Principle:

Principle #15Dynamics

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 multipart punch system reduces the hydraulic force required, lowers tooling costs, and allows for easier feeding of additional blank during hydroforming, while maintaining a flush surface for efficient operation.

Implementation Method 1

a ram having a ram reaction surface to engage the reaction surface of the first punch segment and the reaction surface of the second punch segment, the ram being moveable between an initial position and an extended position

Methodology Applied

Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

a groove extending along a portion of the side of the punch segment perpendicular to the reaction surface, the groove receiving the boss and limiting the movement of the second punch segment relative to the first punch segment

Methodology Applied

Scientific EffectMechanical constraint: Mechanical Force

Data Source

PatentUS8201428B2Multipart punch for hydro piercing

Publication Date: 2012.06.19 MAGNA INTERNATIONAL INC

AI summary

A novel multipart punch and system allows apertures to be formed in hydroformed members with the slug which would otherwise result being divided into two or more smaller slugs. These smaller slugs can be folded back into the hydroformed member and held captive therein or removed if desired. The multipart punch and system provides a flush surface in the hydroforming mold when the punch is in its initial position to allow easy loading and unloading of the mold and to allow additional blank to be fed into the mold during the hydroforming operation, if desired. Also, the hydraulic ram used with the multipart punch need develop less force than an equivalent prior art stepped punch.