Automotive cables, as the "blood vessels" of the entire vehicle's electrical system, must maintain insulating properties under complex working conditions, and abrasion resistance is one of their key indicators. Combined with the requirements of "Resistance to abrasion" in the ISO 6722 standard, this article systematically analyzes the scope of application, equipment composition, test process and technical points of automotive wire scrape abrasion tester.

1. Scope of Application: Definition of Conductor Cross-Sectional Area

According to clause 9.1 of the ISO 6722 standard, the abrasion resistance test is only applicable to automotive cables with a conductor cross-sectional area ≤ 6 mm². If the conductor cross-sectional area is > 6 mm², this test is not required. For cables that meet the test conditions, the customer and supplier shall agree to select one of the test methods: sandpaper abrasion (clause 9.2) or scrape abrasion (clause 9.3). This article focuses on the equipment and process corresponding to scrape abrasion.

2. Equipment Composition: Core Parameters of Scrape Abrasion Tester

The scrape abrasion tester must meet the technical requirements of clause 9.3.2 and figure 7 of ISO 6722. And is mainly composed of a sample clamping system, scrape actuator, and cycle control unit. The specific parameters are as follows:

2.1. Scrape Needle

● Diameter: Two specifications are optional, (0.25±0.01)mm or (0.45±0.01)mm. Determined by the customer and supplier through negotiation.

● Material: Polished spring steel wire that complies with the ISO 6931-1 standard.

2.2. Motion and Force Control System

● Cycle Frequency: (55±5) cycles per minute (one cycle refers to one reciprocating movement of the scrape needle);

● Scrape Displacement: (20±1)mm;

● Scrape Length: (15.5±1)mm;

●   Vertical Load: Apply a total vertical force of (7±0.05)N to the sample during the test;

2.3. Cycle Control and Shutdown Mechanism

The equipment must have cycle counting and automatic shutdown functions: when the scrape needle wears through the insulation layer and makes contact with the conductor, the machine shall automatically stop operating. The number of cycles at this point is the abrasion resistance performance data of the sample.

3. Test Process: From Sample Preparation to Result Determination

3.1. Sample Preparation (Clause 9.3.1)

Prepare a wire sample with a length of 1 m and remove 25 mm of insulation from one end for subsequent test operations.

3.2. Test Procedure (Clause 9.3.3)

Install the sample on the equipment and apply a vertical force of (7±0.05)N;

After each reading, move the sample 100 mm along the axial direction, rotate it clockwise by 90°, and replace it with a new scrape needle before continuing the test.

3.4. Result Requirement (Clause 9.3.4)

The number of cycles for abrasion resistance shall be agreed upon by the customer and supplier. It usually needs to meet the wear-resistant design requirements of the entire vehicle's electrical system, and this data can serve as a key verification indicator for the insulation reliability of automotive wires.

4. Significance of the Equipment: Ensuring the Reliability of the Automotive Electrical System

During the assembly and long-term use of the entire vehicle, automotive wires are prone to friction with surrounding components (such as body sheet metal, other wire harnesses, etc.). The scrape abrasion tester verifies the durability of the wire insulation layer under mechanical wear by simulating such friction conditions. It is one of the core testing equipment to ensure that the automotive electrical system has no short-circuit and no leakage risks, and is of great significance for improving the electrical safety and service life of the entire vehicle.

In conclusion, the automotive cables scrape abrasion tester based on the ISO 6722 standard, provides a scientific and reproducible verification method for the abrasion resistance of automotive cables. It is a key equipment in the R&D, production, and quality control of automotive wires, and also a "gatekeeper" to ensure the reliability of the automotive electrical system.