System for automatically detecting and evaluating early fatigue damage of remanufactured front crankshaft

Abstract

The invention discloses a system for automatically detecting and evaluating early fatigue damage of a remanufactured front crankshaft and belongs to the field of nondestructive testing. According to the system, a probe is arranged in a probe clamp; a detection probe is driven by a portal frame to move over a journal of a connecting rod to be detected, the phase is adjusted to be consistent with the journal of the connecting rod to be detected, and the detection probe is tightly attached to the surface of the journal of the connecting rod; the crankshaft rotates at a constant speed around a center line of a main journal, the journal of the connecting rod eccentrically rotates, the detection probe follows up and rotates at a constant speed round the circumference of the journal of the connecting rod, and a signal acquisition instrument begins to acquire signals; after rotating a circle, the crankshaft is automatically stopped, the signal acquisition instrument stops acquiring signals and uploads the signals; and an industrial personal computer analyzes the data of the signals and gives the fatigue damage degree of the journal of the connecting rod and can save the detection signal. By the system, a complex shape at an R angle of the journal of the connecting rod of the crankshaft can be matched, three damage signals in potential directions at the R angle on two sides of the journal of the connecting rod where fatigue easily occurs can be acquired at the constant speed, and the damage signals of the journal of each connecting rod of the whole crankshaft can be detected.

Description

technical field [0001] The invention relates to an automatic detection and evaluation system for early fatigue damage of a crankshaft before remanufacturing, and belongs to the technical field of nondestructive testing. Background technique [0002] The crankshaft is an important working part of the engine. Its structure and shape are complex and its service conditions are harsh. During operation, there is a strong stress concentration at the transition corner between the journal and the crank arm - the R corner, which is likely to cause fatigue damage to the crankshaft. [0003] Due to the harsh working conditions, the quality requirements of the crankshaft are high, and the remanufacturing value is high. Therefore, crankshaft remanufacturing is an important task for automobile remanufacturing companies. Before remanufacturing, it is first necessary to evaluate the life of the remanufactured crankshaft blank (that is, the used crankshaft) to determine its remanufacturing va...

AI Technical Summary

Problems solved by technology

All the Chinese invention patents listed above require manual operation to replace the connecting rod journal to be tested. Manual operation determines the starting point of detection and detection to ensure that the phase of the detected connecting rod journal is the same; all patents are only for the magnetic memory signal of the R angle of the connecting rod journal. The damage evaluation criteria are not given; all patents use single-point probes, which can only detect the R angle of one side of the connecting rod journal each time, the detection efficiency is low, the detection range is small, and it cannot be completely detected. Cover all possible fatigue cracks at the R corner of the connecting rod journal, which may easily cause missed inspections

Cannot adapt to the requirements of automatic, fast and efficient testing and evaluation of remanufacturing factories

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