Vision Measuring Machine for New Energy Vehicle Parts: Value in Geometric Dimension Measurement for Tolerance Control

As the new energy vehicle (NEV) industry accelerates toward high integration and lightweight design, dimensional tolerances of components have tightened from the traditional hundred-micron level to the micron level. The sealing safety of battery systems, efficient operation of electric drive systems, and precision assembly of body structures all depend heavily on accurate geometric dimension measurement. Meeting these increasingly strict tolerance requirements in mass production has become a critical challenge for the EV supply chain. Sinowon’s self-developed fully automatic vision measuring machine, based on high-precision optical dimensional measurement technology, provides a reliable quality control solution for NEV components.

What is Dimensional Measurement and How Does a Vision Measuring Machine Work?

Dimensional measurement refers to the quantitative evaluation of linear dimensions (length, width, height, hole diameter, etc.) and geometric tolerances (flatness, position, concentricity, etc.) of workpiece features. A fully automatic vision measuring machine uses optical imaging principles: a high-resolution camera captures 2D or 3D images of the part, combined with sub-pixel edge extraction algorithms and computer graphics processing, to achieve non-contact high-accuracy measurement. Compared with traditional contact gauges, the vision measuring machine avoids the risk of scratching the part surface and delivers higher efficiency for batch inspection of complex geometric features.

What Can Sinowon’s Fully Automatic Vision Measuring Machine Measure for EV Parts?

Sinowon’s fully automatic vision measuring machine precisely measures points, lines, circles, arcs, length, width, height, as well as geometric tolerances including straightness, flatness, profile, parallelism, inclination, perpendicularity, symmetry, concentricity, coaxiality, and position. Below are five major application categories:

1. Battery System Components

The safety and sealing of EV battery packs directly depend on component dimensional accuracy. Sinowon’s vision measuring machine accurately measures key parameters such as battery housing dimensions, electrode spacing, and seal inner/outer diameters, helping ensure assembly sealing and safety. Specifically, it measures flatness across the entire length of the battery housing (ensuring sealing surface flatness to meet IP67/IP68 requirements), position of mounting holes (avoiding assembly misalignment), and groove profiles. For electrode tabs, burr length and width can be inspected with accuracy up to ±1 μm.

2. Motor and Electric Drive System Components

Motor housings, stator and rotor assemblies require strict position tolerances and concentricity of holes and shafts. Sinowon’s cantilever-type fully automatic vision measuring machine (MVS series) has been applied at several NEV manufacturers, mainly for batch inspection of motor cones, miniature shafts, and similar parts. The system automatically recognizes circle centers, measures hole diameters and distances from holes to edges, and calculates multi-hole position tolerances – significantly reducing the risk of screw mismatches during assembly.

3. Die-Cast Aluminum Alloy and Lightweight Structural Parts

NEVs widely use aluminum die-castings for lightweighting, but these parts are prone to burrs, porosity, and complex geometries with tight tolerances. Sinowon’s vision measuring machine uses ring light and coaxial light with multiple illumination angles to achieve sharp edge imaging for parts such as engine brackets, transmission housings, and steering knuckles. Specific measurement capabilities include:

• Flatness/parallelism (cylinder block mating surfaces)
• Position/concentricity analysis (bearing bore systems)
• Perpendicularity inspection (mounting reference planes)
• Bore/shaft diameter measurement (tolerance ±2 μm)
• Center distance inspection
• Profile evaluation

A case study: after adopting Sinowon equipment, an automotive parts supplier reduced single-part inspection time from 45 minutes to 15 minutes, with repeatability of hole position ≤ ±3 μm.

4. Seals and Assembly Components

Sealed aluminum covers and sealing rings are critical for battery packs and motor housings. Sinowon’s vision measuring machine can perform:

• Length, width, height measurement
• Inner/outer diameter measurement
• Flatness, roundness, parallelism evaluation
• Edge shape and edge sharpness inspection
• Surface crack, scratch, and pit detection
• Assembly dimension measurement to improve fit reliability
• Shape comparison between measurement results and design files to evaluate manufacturing accuracy and consistency

5. Stamped Sheet Metal and Structural Parts

For large stamped parts such as battery trays, Sinowon’s large-travel fully automatic vision measuring machine uses a granite gantry moving structure with travel up to several thousand millimeters, enabling single-position setup and full-area measurement. The system automatically collects hundreds of height data points across the entire surface, generates a color 3D flatness cloud map with micron-level quantification, measures the profile of complex irregular edges, inspects cutting machine accuracy, and automatically judges whether dimensions meet standards.

Solving Four Common Challenges in NEV Parts Inspection

Challenge 1: Tightening Tolerances Exceed the Limits of Manual Tools

With electric drive systems requiring dimensional tolerances ≤5 μm, traditional calipers and micrometers are insufficient. Sinowon’s fully automatic vision measuring machine is equipped with high-precision linear scales and sub-pixel edge extraction algorithms, achieving micron-level repeat accuracy (tested per ISO 10360) and meeting the automotive industry’s IATF 16949 requirement for measurement system capability (GR&R ≤10%).

Challenge 2: High Volume and Wide Variety Demand Efficiency

NEV parts come in many types, shapes, and sizes with large batch volumes. Sinowon’s vision measuring machine supports CNC fully automatic programming and “one-click measurement.” Once a program is set, operators need only simple training – pressing start triggers automatic movement, automatic focusing, and automatic OK/NG judgment. Since 2021, one NEV company has continuously purchased Sinowon MVS series and iMS-3020 equipment, significantly improving inspection efficiency and reducing rework rates.

Challenge 3: Large Parts Are Difficult to Fully Measure

Large components like battery trays (several meters long) and drive housing cannot be adequately measured with traditional segmented methods or tape measures, risking missed detection of critical deformation zones. Sinowon’s large-travel vision measuring machine provides a one-piece full-size coverage solution, effectively reducing the miss rate of defective parts.

Challenge 4: Data Traceability Gaps – Incomplete Quality Loops

Every measurement is automatically archived. With SPC software, historical records can be reviewed at any time to analyze process capability and support process improvement. The system automatically generates inspection reports compliant with IATF 16949, enabling full traceability of quality data throughout the process.

Conclusion

In the “micron-level race” of dimensional tolerance control for NEV components, Sinowon’s fully automatic vision measuring machine delivers high accuracy, high efficiency, and non-contact measurement across all major inspection needs – from battery housings, motor parts, and die-cast structural components to seals and large sheet metal parts. Sinowon continues to advance vision measurement technology, helping the NEV industry move from sampling inspection to full inspection, and from millimeter to micron quality levels.

Visit our official website www.sinowon.com for more product details and to obtain geometric dimension measurement solutions for NEV parts.