Development of Technique to Measure Stress on Connecting Rod during Firing Operation

When measuring the stress generated on connecting rods during operation with a strain gauge there are technical problems in taking the signal wires outside of the engine. As a means to solve this problem, we have developed a wire take-out method which consists of a steel wire to hold the signal wire and a tensioner to give tension to the steel wire. The adoption of this technique made it possible to measure the stress on connecting rods at a high speed range exceeding 10,000rpm, which has been impossible before.

The results of analysis obtained by the wire take-out method revealed that speed ranges exceeding 10,000rpm generated a high frequency fluctuation due to the bending vibration of the connecting rod.