Fully Automatic Electronic Expansion Valve (EEV) Coil Assembly Line

Fully Automated Electronic Expansion Valve (EEV) Coil Assembly Line

1. Product Introduction: An Industry Benchmark for Precision Valve Coils

The SIPU Electronic Expansion Valve (EEV) Coil Assembly Line is a high-speed, fully automated manufacturing solution designed for the HVAC and electric vehicle (EV) industries. It processes raw materials such as plastic coil frames, copper wire, and metal housings into fully tested, IP67-rated stepper motor stators.

Unlike traditional winding machines that require manual assembly, this turnkey production line integrates precision winding, stator assembly, and quality inspection into a continuous workflow. It is specifically designed to meet the zero-defect standards of leading air conditioning, heat pump, and automotive thermal management system manufacturers.

The Full Assembly Line View

2. The 4-Stage Automated Manufacturing Process

This production line is not just a collection of stations; it is a synchronized ecosystem. Here is how we ensure quality at every step:

Phase 1: Precision Winding & Pin Insertion
The process begins with the automatic feeding of bobbins. Our 12-spindle winding station, equipped with active servo tensioners, winds the copper wire with consistent tension to ensure stable resistance and inductance. Simultaneously, terminal pins are inserted with micron-level accuracy, preparing the interface for connection.

Phase 2: Stator Assembly & Claw Pole Encapsulation
The wound coil is then mated with the upper and lower metal claws (yokes). The machine automatically aligns and presses the metal housing over the coil, creating the fundamental structure of the PM Stepper Motor Stator.

Phase 3: The SIPU Innovation – "Claw Pole Shaping"
This is where SIPU stands out. We have integrated a proprietary Claw Pole Shaping Station. Unlike competitors who rely on simple pressing, our machine applies multi-directional force to "shape" and lock the metal casing. This ensures perfect concentricity and mechanical rigidity, eliminating vibration noise during valve operation.

Phase 4: Automatic OK/NG Sorting

Instead of manual checking, the machine features an intelligent Sorting System.

Throughout the assembly process, sensors monitor critical parameters (e.g., servo position, assembly pressure).

Qualified Products (OK): Successfully assembled stators are automatically unloaded onto the output tray/conveyor.

Unqualified Products (NG): If any process error is detected (e.g., missing part, assembly misalignment), the machine automatically routes the unit to a separate Reject Bin, preventing defective parts from mixing with good ones.

3.Technical Specifications

6. Frequently Asked Questions: Technical and Application Consulting

Q1: Why is the "claw pole forming" process so important?

A: Standard pressing processes typically leave tiny gaps between the metal claws and the spool. Our unique forming technology applies multi-directional forces to tightly lock the metal structure. This ensures the electric vehicle stator has mechanical rigidity and vibration resistance, which is crucial for the low-noise operation of electric vehicles and air conditioning systems.

Q2: Is this production line a standard or custom model?

A: This is a fully customized solution. We design the production line structure and fixtures strictly according to your specific stator drawings and cycle time requirements.

While the core technologies (winding and forming) are general, machines specifically designed for your product ensure maximum stability and the highest yield (over 99.5%), far surpassing general-purpose machines.

Q3: What applications is this assembly line suitable for?

A: This production line is specifically designed for producing permanent magnet stepper motor stators (claw pole type). These components are widely used in:

Electric Vehicle Thermal Management: Electronic expansion valves (EEV) for battery cooling systems.

HVAC Industry: Variable frequency air conditioning valves and heat pump control valves.

Refrigeration: Intelligent control valves for commercial freezers.

Q4: How does the machine handle defective products?

A: The machine is equipped with an intelligent automatic sorting system. Sensors monitor key steps in real time (winding tension, assembly pressure). If any abnormality is detected, the machine marks the unit as "NG" (non-conforming) and automatically sends it to the scrap bin, ensuring that only 100% qualified parts reach the unloading pallet.

Q5: Can the finished stator be directly injection molded (overmolding)?

A: Yes. Our claw pole molding process ensures precise dimensional control (concentricity and outer diameter). This guarantees that the stator can be perfectly fitted into your PBT injection mold for the final overmolding process, thus preventing mold damage or flash issues.

Q6: What is the lead time for a customized EEV production line?

A: Typically, the design and manufacturing process takes 3 to 4 months. This includes mechanical design, machining, assembly, and a rigorous 72-hour no-load test using your sample materials before shipment to ensure your factory is plug-and-play ready.

Please contact us to get more informations.