Terminal Fitting with Fastening Caulking for Wire Connection

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Solution Overview

Problem

Existing connection structures for terminal fittings, which stack multiple fittings to connect grounding electric wires, result in increased weight and thickness, require significant space, and often necessitate costly holding mechanisms, while also risking reliability due to bolt loosening and variations in crimping strength.

Innovation Solution

A connection structure and method using terminal fittings with fastening caulking pieces and concave-convex engagement portions that allow for secure, lump connection of electric wires without stacking, eliminating the need for holding mechanisms and minimizing weight and space, while ensuring high reliability through stable crimping and adjustable terminal connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If terminal fittings are stacked to connect multiple grounding electric wires, then the number of wires that can be connected increases, but the weight and thickness of the connection structure increase

Engineering Contradiction:

Improvenumber of electric wires connectedVSAvoidweight of connection structure

Core Design Contradiction:

Quantity of substanceVSWeight of stationary object

Solution Approach 1:

The patent merges multiple terminal connection portions into a single terminal fitting body, allowing multiple electric wires to be connected to one fitting rather than stacking multiple fittings. The terminal fitting includes a body with multiple terminal connection portions extending from it, each capable of connecting to a connection terminal, thereby connecting multiple wires in a unified structure that reduces overall weight.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The terminal fitting is segmented into distinct functional parts: the terminal body and multiple terminal connection portions extending from it. Each terminal connection portion can independently connect to a connection terminal, allowing the structure to accommodate varying numbers of wires while maintaining a compact, non-stacked configuration.

Inventive Principle:

Principle #1Segmentation

2Quantity of substance

If terminal fittings are stacked to connect multiple grounding electric wires, then the number of wires that can be connected increases, but the space required above the grounding surface increases

Engineering Contradiction:

Improvenumber of electric wires connectedVSAvoidthickness of connection structure

Core Design Contradiction:

Quantity of substanceVSLength of stationary object

Solution Approach 1:

Multiple terminal connection portions are merged into a single terminal fitting body arranged substantially in one plane, eliminating the need to stack fittings vertically. This planar arrangement reduces the thickness direction dimension while allowing multiple wires to be connected simultaneously.

Inventive Principle:

Principle #5Merging (Combining)

3Strength

If connection terminals are crimped to terminal fittings, then firm connection is achieved, but variation in crimping strength occurs due to unstable postures

Engineering Contradiction:

Improveconnection strengthVSAvoidcrimping strength consistency

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The terminal connection portions are pre-formed with engagement portions (convex and concave features) that guide and stabilize the posture of connection terminals before crimping occurs. This preliminary positioning ensures consistent alignment and posture during the crimping process, reducing variation in crimping strength.

Inventive Principle:

Principle #10Preliminary action

4Ease of manufacture

If bolts are used to fasten terminal fittings, then connection is achieved, but reliability deteriorates over time due to bolt loosening

Engineering Contradiction:

Improveease of assemblyVSAvoidconnection reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces the bolt fastening mechanism with a crimping mechanism that creates a permanent deformation bond between the connection terminal and terminal fitting. The connection terminal includes fastening caulking pieces that are crimped onto the terminal connection portion, substituting the reversible mechanical fastening of bolts with an irreversible metallurgical bond that does not loosen over time.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

5Quantity of substance

If joint connectors with holding mechanisms are used to connect multiple wires, then lump connection is achieved, but the housing size increases and cost increases

Engineering Contradiction:

Improvenumber of electric wires connectedVSAvoidstructure complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent extracts the holding mechanism from the connector structure, eliminating the need for a separate housing to hold connection terminals. Instead, the terminal fitting body itself with its multiple terminal connection portions serves as both the connection and holding structure, simplifying the overall design.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The terminal fitting body performs multiple functions: it provides the grounding connection point, holds multiple connection terminals through its terminal connection portions, and eliminates the need for a separate housing. This multi-functional design reduces structural complexity and cost.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 solution enables reliable, space-efficient, and cost-effective connection of multiple electric wires of varying sizes without the need for stacking or specialized holding mechanisms, maintaining connection strength and stability across different wire configurations.

Implementation Method 1

the pair of the fastening caulking pieces are caulked with opposite side portions of a corresponding one of the terminal connection portions from outside so that the connection terminal is caulked and fastened to the terminal fitting

Methodology Applied

Scientific EffectCaulking: Mechanical Fastener

Implementation Method 2

concave-convex engagement portions are provided in opposed surfaces in which the terminal connection portion and the terminal bottom portion abut against each other

Methodology Applied

Scientific EffectMechanical interlocking: Mechanical Fastener

Data Source

PatentUS9948014B2Connection structure and connection method for terminal fitting

Publication Date: 2018.04.17 YAZAKI CORP

AI summary

A connection structure of a terminal fitting includes the terminal fitting including a terminal body, and a plurality of terminal connection portions extending from the terminal body and connection terminals connected to end portions of electric wires. Each of the connection terminals includes a pair of fastening caulking pieces which erects on opposite side portions of a terminal bottom portion. The pair of the fastening caulking pieces are caulked with opposite side portions of a corresponding one of the terminal connection portions from outside so that the connection terminal is caulked and fastened to the terminal fitting. Concave-convex engagement portions are provided in opposed surfaces in which the terminal connection portion and the terminal bottom portion abut against each other. The terminal fitting is connected to the electric wires through the connection terminals.