Core Process Principles and Scope of Application

The core logic of ferrule crimping is the "Cold Weld" effect. High-intensity pressure induces plastic deformation in the terminal’s metal sleeve, binding multi-stranded flexible wires into a compact, confined space.

• Physical Essence: The crimping force expels air from between the wire strands, allowing the contact surfaces to achieve atomic-level proximity, which effectively prevents oxidation.
• Applicable Scenarios: Primarily used for stranded wires.
• Key Advantages: It solves the common issues encountered when inserting flexible wires directly into screw terminals, such as wire breakage, high contact resistance, and loosening caused by thermal cycling.

Pre-Crimping Preparation: Materials, Tools, and Pre-processing

Process Segment	Key Requirements
Material Matching	Must follow the 1:1:1 Rule: Wire Gauge = Terminal Specification = Die Specification.
Equipment Selection	Prioritize the use of Quadrilateral (4-point) or Hexagonal (6-point) crimping tools.
Wire Inspection	Verify that conductors are free of oxidation (blackening) and broken strands, and that the insulation layer has no cracks.

Standard Crimping Workflow (Automation Upgrade)

In the manual era, stripping and crimping were separate tasks. In an automated workflow, these two steps are highly integrated to prevent strand splaying and oxidation.
Example Case: TM-E140 Pre-insulation Ferrule Terminal Strip And Crimp Machine

1.Parameter Setting & Pre-check
Equipment Initialization
Adjust the stripping depth and crimping stroke of the TM-E140 based on the wire gauge. Ensure the ferrule specifications (e.g., E1508) in the vibratory bowl feeder perfectly match the current wire being processed.

2.Wire Feeding
Sensor Trigger
Feed the wire horizontally into the machine’s inlet. Automated machines are typically equipped with sensors that automatically trigger the stripping action once the wire reaches the preset position.

3.Precision Stripping
Zero-damage Core Protection
The machine utilizes V-shaped stripping blades to precisely cut the insulation. Unlike manual stripping, the integrated stripping-crimping machine ensures a constant strip length and prevents secondary twisting or splaying because the crimp happens instantaneously.

4.Instant Twisting
Preparation for Insertion
Immediately after stripping, the machine automatically performs a wire twisting motion. This keeps the strands tight and aligned, preparing them for smooth insertion into the ferrule.

5.Ferrule Positioning & Insertion
Automated Feeding
The vibratory bowl feeder aligns and pushes the terminals to the crimping station. The internal mechanism then guides the stripped wire core precisely into the bell-mouth of the ferrule.

6.High-Precision Crimping
Inverter Motor Driven
The TM-E140 employs inverter control, providing a more stable pressure curve than pneumatic or manual tools. This ensures perfect plastic deformation of the metal sleeve, achieving the "Cold Weld" effect.

7.Quality Inspection
Real-time Monitoring
Examine the finished product. Check for a slight protrusion of the wire core (0–0.5 mm) from the front of the ferrule and ensure the wire insulation is perfectly encased by the terminal's collar.

8.Pull-out Force Sampling
Physical Verification
Periodically take samples from the production line for tensile testing (per IEC 60352-2 standard) to ensure the machine maintains stable pressure output during long-term operation.

Quality Enhancement through Automation
By implementing automated crimping machines, you can achieve technical improvements across the following three dimensions:

• Pressure Consistency: The inverter-driven motor eliminates the inconsistent force typically caused by operator fatigue in manual crimping processes.
• Space Efficiency: The cross-section after automated crimping is extremely dense (void rate < 5%), ensuring smoother insertion of terminals into compact PLC modules.
• Material Savings: An exceptionally high success rate reduces the waste of terminals and expensive cables caused by crimping defects.

Quality Acceptance Standards (National & International Standards)

4.1 Core Standards & References
National Standards (GB): GB/T 14315-2008 (Crimping terminals for power cables); GB/T 18290.2-2015 (Equivalent to IEC 60352-2).
International Standards: IEC 60352-2:2024 (Solderless connections - General requirements); UL 486A/B (Standard for Safety for Wire Connectors).

4.2 Acceptance Indicators

Dimension	Acceptance Criteria	Inspection Tools
Appearance	No cracks, bulges, or burrs in the crimping zone; no exposed core strands; no damage to the insulation layer.	Visual Inspection + Caliper
Mechanical Performance	Tensile Test: $\ge 50N$ for $1.5mm^2$ wire; zero relative displacement between terminal and conductor.	Pull Force Tester
Electrical Performance	Contact Resistance: $\le 1.1\times$ the resistance of an equivalent length of wire; Insulation Resistance: $\ge 1M\Omega$ (tested at 500V).	Micro-ohmmeter, Megohmmeter
Dimensional Accuracy	Outer diameter deviation after crimping $\le \pm5\%$; indentation depth must conform to die specifications.	Digital Caliper

Common Issues and Solutions

Issue Type	Typical Manifestation	Root Cause	Solution
Loose Connection	Overheating after power-on; resistance exceeds standards.	Wire core not fully inserted; crimping height is too high.	Recalibrate stripping length; adjust crimp parameters; re-crimp and re-test resistance.
Core Breakage	Wire breaks during tensile test; terminal falls off.	Over-crimping; insufficient stripping length.	Adjust crimping height to 70%–80% of original diameter; standardize stripping to avoid core damage.
Crimping Cracks	Visible cracks on terminal; open circuit after power-on.	Incorrect parameter settings; crimping speed is too fast.	Readjust parameters; ensure steady and uniform pressure application.
Poor Contact	Signal fluctuation; intermittent power loss.	Conductor oxidation; lack of conductive paste.	Clean oxidation layer from core; apply electrical joint compound; re-crimp.
Insulation Damage	Leakage; risk of short circuit.	Stripping length too long; insulation damaged during crimping.	Precisely control stripping length; use appropriate stripping machines; avoid excessive force.

Operational Precautions & Safety Standards

• Equipment Maintenance: Periodically calibrate the crimping machine. Inspect and clean worn components to prevent mechanical wear from compromising crimping quality.
• Environmental Requirements: Operate in a dry, dust-free environment. Avoid high-humidity or corrosive atmospheres to prevent terminal oxidation.
• Safety Protocols: Perform operations only after power-off verification. Wear insulated gloves and strictly prohibit touching energized terminals with bare hands.
• Batch Quality Control: Conduct random sampling (10%) for each batch. If any defect is found, perform a 100% inspection to ensure consistent process quality.

Summary

High-quality ferrule crimping is the cornerstone of industrial electrical automation. The essence of mastering this technology lies in the professionalization of tools and the standardization of workflows. By strictly implementing the "Seven-Step Method" and standardized acceptance procedures, over 95% of potential electrical connection hazards can be eliminated.