Relay Coil Pin Structure for Secure Signal Wire Fixation

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Solution Overview

Problem

Existing relays face issues such as rust and oxidation at split riveting positions, inability to achieve over-travel adjustment in automated assembly, armature or moving spring jamming, lack of contact conductivity detection, large arcs in high-current environments, and insufficient contact life monitoring.

Innovation Solution

The relay coil assembly features a coil pin with inverted hooks and slope sections for secure signal wire fixation, adjustable over-travel through hook members, armature protection via housing protrusions, and signal monitoring via protruding contact pieces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If split riveting is used to fix the magnetic circuit to the base, then anti-withdraw fixation is achieved, but the split position is easy to rust and oxidize affecting relay normal use

Engineering Contradiction:
Improvefixation strengthVSAvoidrust and oxidation resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent removes the magnetic circuit from the base structure, allowing independent optimization of both components. The magnetic circuit can be fixed using alternative methods that avoid the rust and oxidation issues of split riveting, while the base maintains its structural integrity without requiring rivet holes.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a magnetic circuit fixing structure as an intermediary component between the magnetic circuit and the base. This fixing structure can be designed with rust-resistant materials and methods, mediating the connection without exposing critical junctions to corrosion.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If hot riveting is used to fix the bobbin to the base, then anti-withdraw fixation is achieved, but over-travel adjustment cannot be performed in automated assembly process

Engineering Contradiction:
Improvefixation strengthVSAvoidover-travel adjustment capability
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The patent transforms the fixed bobbin structure into a dynamically adjustable one by introducing a bobbin fixing structure with adjustable components. This allows the bobbin position to be modified for over-travel adjustment while maintaining secure fixation, enabling both strong attachment and post-assembly tuning.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent incorporates preliminary adjustment mechanisms into the bobbin fixing structure during manufacturing. This allows over-travel parameters to be pre-set and adjusted before final assembly, enabling automated assembly processes to accommodate different relay specifications without requiring post-assembly modifications.

Inventive Principle:
Principle #10Preliminary action

3Strength

If the housing is impacted or squeezed from the upper direction, then the inner wall deforms downward pressing on the armature or moving spring, but the armature or moving spring becomes stuck and cannot move causing relay failure

Engineering Contradiction:
Improvehousing strengthVSAvoidarmature movement reliability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies preliminary anti-action by designing the housing with pre-formed protrusions that counteract deformation forces before they reach the armature. These structural features prevent the housing wall from deforming inward under impact, proactively protecting the armature movement path from obstruction.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent introduces cushioning elements or protective structures between the housing and the armature/moving spring. These elements absorb and distribute impact forces, preventing direct transmission of deformation to the moving components, thereby cushioning against potential jamming.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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

Ensures reliable signal wire connection, allows over-travel adjustment, prevents armature jamming, reduces arc size, and enables contact life monitoring, enhancing relay performance and reliability.

Implementation Method 1

the coil generates a magnetic field by passing a small current to the coil, and the armature is attracted or released by use of the generation or disappearance of the magnetic field

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3961669B1Relay coil assembly
Publication Date: 2025.11.26 XIAMEN HONGFA AUTOMOTIVE ELECTRONICS CO LTD
  • EP3961669B1 patent drawingFigure 1~2
  • EP3961669B1 patent drawingFigure 3~4
  • EP3961669B1 patent drawingFigure 5~6

AI summary

Disclosed is a relay coil assembly, comprising a coil frame, an enameled wire, a coil pin, and a signal wire. The coil pin comprises an insertion portion, an enameled wire fixing portion, and a signal wire fixing portion. The signal wire fixing portion is provided with a first engagement recess having an opening facing downward, and the signal wire is engaged in the first engagement recess. A hook element is provided near the edge of the opening and at one of two recess sidewalls of the first engagement recess. A slope section along which the opening gradually enlarges from inside to outside is provided at a location corresponding to the signal wire at one of the two recess sidewalls of the first engagement recess. The invention avoids deficiencies of the prior art when fixing a signal wire to a coil pin of a relay coil assembly by means of welding, and enables a secure and reliable connection between the signal wire and the coil pin in the relay coil assembly.