Segmented Punch Joining for Interlock Formation in Unequal-Strength Plates

Solution Overview

Problem

Conventional joining apparatuses face difficulties in forming interlock portions when the strength of the upper plate is lower than the lower plate, as the metal from the upper plate flows outward, hindering the formation process.

Innovation Solution

A joining apparatus with a punch featuring an inner and outer punch portion, allowing for the formation of a depression at the front end, which secures the metal for extrusion and enables the formation of an interlock portion even when the upper plate's strength is lower, using a die and punch configuration with a recess and annular groove.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a conventional punch without a depression is used, then the joining apparatus is simple, but the interlock portion cannot be formed when the upper plate strength is lower than the lower plate strength

Engineering Contradiction:

Improvejoint strengthVSAvoidpunch structure complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The punch is divided into an inner punch portion and an outer punch portion that are movable relative to each other. The outer punch portion forms a depression while the inner punch portion extrudes metal, allowing the formation of interlock portions even when the upper plate has lower strength than the lower plate.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The outer punch portion forms a depression at the front end of the punch before the actual joining process. This depression secures the metal from the upper plate, preventing it from flowing outward and ensuring sufficient metal is available for forming the interlock portion.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If the upper plate and lower plate are pressed toward the recess without a depression, then the process is simple, but the metal flows circumferentially outward and the interlock portion formation is hindered

Engineering Contradiction:

Improveinterlock portion formation precisionVSAvoidprocess complexity

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The outer punch portion forms a depression at the front end of the punch before the actual joining process. This depression secures the metal from the upper plate, preventing it from flowing outward and ensuring sufficient metal is available for forming the interlock portion.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The depression formed by the outer punch portion acts as an intermediary structure that temporarily holds the metal from the upper plate. This intermediary feature prevents direct circumferential flow of metal and ensures controlled metal availability for interlock portion formation.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Quantity of substance

If the inner punch portion and outer punch portion are fixed together, then the punch structure is simple, but the depression cannot be formed and metal cannot be secured

Engineering Contradiction:

Improvemetal quantity in depressionVSAvoidpunch structure complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The punch is divided into an inner punch portion and an outer punch portion that are movable relative to each other. The outer punch portion forms a depression while the inner punch portion extrudes metal, allowing the formation of interlock portions even when the upper plate has lower strength than the lower plate.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The inner punch portion and outer punch portion are configured to be movable relative to each other, allowing the outer punch portion to form a depression and the inner punch portion to subsequently extrude metal. This dynamic configuration enables controlled metal securing and extrusion.

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

Enables the successful formation of interlock portions between plate members with differing strengths, ensuring a secure joint by extruding metal from the depression, thus overcoming the limitations of conventional methods.

Implementation Method 1

the inner punch portion and the outer punch portion are moved relative to each other so as to extrude the metal in the depression by the inner punch portion

Methodology Applied

Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

the die and the punch are moved relative to each other so as to press and deform the multiple plate members toward the recess by the punch

Methodology Applied

Scientific EffectMechanical force: Mechanical Force

Data Source

PatentUS10933459B2Joining apparatus and manufacturing method for joint

Publication Date: 2021.03.02 TOYOTA JIDOSHA KK

AI summary

A joining apparatus includes: a die having a recess; and a punch disposed opposite to the recess. The punch includes an inner punch portion and an outer punch portion disposed around the inner punch portion, the inner punch portion and outer punch portion are configured to be movable relative to each other, and a depression is formable at a front end of the punch. The joining apparatus is configured such that, in a state in which the depression is formed at the front end of the punch, the punch is moved relatively so as to press and deform the multiple plate members toward the recess by the punch, and the inner punch portion is moved relatively so as to extrude a metal in the depression by the inner punch portion.