Kustomisasi konektor presisi ultra-panjang untuk produsen peralatan industri AS: Mengatasi tantangan ulir ramping 180mm dan knurling

Core products: "Industrial-grade indicators" of high-precision slender rod connectors for high-pressure environments

The customized product is a 304 stainless steel high-pressure connector , with core technical parameters:

1. Overall dimensions: total length 180mm, rod diameter 6mm (length-to-diameter ratio 30:1), one end M5 × 0.8 fine thread (matching hydraulic quick connector), thread effective length 10mm, tolerance ± 0.02mm;
2. Surface treatment: knurling in the middle 155mm area (pitch 0.6mm, depth 0.25mm, surface hardness HV <000000>ge; 220), meeting the anti-slip requirements of wearing protective gloves in industrial scenarios;
3. Sealing system: A customized nitrile rubber ring (Shore hardness 80A) is embedded in the groove between the knurled end and the threaded end, which needs to pass the 15MPa water pressure test and -20 ℃ ~80 ℃ temperature resistance cycle test.

• Insufficient rigidity and machining deformation of slender rods:

  • Slender rods with a length-to-diameter ratio of 30:1 are prone to bending due to vibration during cutting. The traditional machining straightness error is 0.2mm, far exceeding the customer's requirement of 0.05mm;

• Fine thread accuracy and high-pressure sealing:

  • The tolerance band of the M5 × 0.8 thread mid-diameter is only 0.04mm. If the accuracy is insufficient, it will cause hydraulic joint leakage (the original supplier's missed detection rate is 15%), which directly affects the safety of equipment operation;

• Wear resistance consistency of the extra-long knurled area:

  • Frequent plugging and unplugging in industrial operations can easily lead to knurl wear. The original solution has a 30% attenuation of the end knurl depth, and the surface roughness exceeds the customer's requirement of Ra <000000>le; 1.6 μ m.

Manufacturing process: full-process solution for industrial-grade precision machining

1. High-precision machining and rigidity enhancement of slender rods

• Equipment and tooling upgrade: Use precision CNC lathes imported from Japan, with t hree-point elastic center frame (support points set every 60mm), 5 passes (single cutting depth <000000>le; 0.08mm), and install vibration dampers on the tool handle;
• Material processing: After rough machining, tempering treatment (850 ℃ quenching + 600 ℃ tempering) is performed to improve material rigidity. After fine machining, the straightness is controlled at 0.03mm, and the roundness error is <0.01mm.

2. M5 × 0.8 high-pressure thread processing technology

• Customized coated taps: German Cobalt-containing taps (TiCN coating) are selected, with high-pressure internal cooling cutting fluid (pressure 5MPa), spindle speed 150rpm during processing, synchronous feed to ensure pitch error <0.008mm;
• Full-size inspection: Use thread comprehensive measuring machine to detect the middle diameter, pitch, and tooth angle, the size is controlled at 4.675 ± 0.015mm (better than customer tolerance requirements), and pass the 15MPa air pressure sealing test (no leakage after 30 minutes of pressure maintenance).

3. Development of ultra-long wear-resistant knurling process

• Segmented carbide knurling wheel: Design of stepped knurling wheel (front guide section, middle reinforcement section, end calibration section), using YG8 carbide (hardness HRA90), the tooth shape is formed by precision grinding, and the pitch accuracy is ± 0.01mm;
• Constant pressure knurling technology: During the knurling process, the pressure sensor is used for real-time feedback, and the axial pressure (2.5-3.5 tons) is automatically adjusted to ensure that the uniformity error of the 155mm knurling depth is less than 0.03mm. The surface hardness is increased to HV230 after heat treatment, and the wear resistance life is increased by 50% compared with the traditional process.

4. Customized development of high-pressure sealing rubber rings

• Working condition adaptation design: According to the customer's hydraulic system parameters (15MPa pressure, mineral oil medium, 80 ℃ high temperature), high wear-resistant nitrile rubber (NBR-70) is selected, and the inner diameter of the rubber ring is designed to be 6.3mm (interference fit 0.1mm) through compression molding + secondary vulcanization process, and the compression rate is controlled at 18%;
• Strict test verification: Complete 1000 plug-in fatigue tests, 100 hours high temperature aging test (80 ℃ ) and 15MPa water pressure pulse test (5000 cycles without leakage), and the missed detection rate is reduced to 0.

• Performance breakthrough: "The 180mm long connector has zero leakage under 15MPa pressure, and the knurled part can be stably operated even with thick gloves, which completely exceeds our expectations for long-size precision processing." - Mr. Davis, Chief Engineer of IT
• Delivery and production capacity: The first sample delivery cycle is 25 days (the industry average is 40 days), the batch production yield is 98.2%, and the annual production capacity is 100,000 pieces, meeting the scale needs of multiple hydraulic system projects of customers.

This cooperation not only solved the customer's short-term delivery problem, but also set a benchmark for the long-size customization of high-pressure fluid system components through breakthroughs in industrial-grade precision machining technology. In the industrial equipment supply chain, when "conventional machining" cannot meet the needs of extreme working conditions, only by focusing on the full-chain innovation of materials, processes, and testing can we become the core technology partner of high-end manufacturing companies.