Eddy Current Non-destructive Inspection device ECNI-II

1. Product summary

The quality of surface treatments such as heat treatment and shot peening is controlled by process control and sampling inspection in the processing equipment, but the current situation is that the shipped products themselves cannot be inspected. For this reason, there is a demand for non-destructive inspection technology that can inspect surface-treated products non-destructively and that anyone can handle, and the eddy current non-destructive inspection device ECNI-II meets this demand.

This product is a non-destructive inspection device that inspects the inside of a surface-treated product without destroying it by a method using magnetic force called the eddy current method. By quantifying the state of the surface treatment, even an inexperienced field worker can determine whether the surface treatment is good or bad. In addition, since it can be incorporated into the production line, in-line all-point inspection is mainly performed by this product on the production line of automobile gears. It is also used not only for surface treatment abnormality inspection, but also for material discrimination inspection before treatment.

Fig. 1 Eddy current non-destructive inspection device ECNI-II.

2. Product content

2.1 About the eddy current method
Fig. 2 shows a schematic diagram in which eddy currents are generated. The eddy current is a current generated by irradiating a conductor such as a steel material with a magnetic field that changes with time. When a conductor is placed inside the coil, an eddy current flows on the side surface of the conductor surrounded by the coil. When the strain such as elastic strain or plastic strain of the metal structure changes due to the surface treatment or when the phase transformation occurs, the electromagnetic characteristics of the conductor change. Since the reaction of eddy current changes due to changes in electromagnetic characteristics, it is possible to inspect surface-treated products. In addition, since the depth of eddy current permeating the conductor changes depending on the frequency of the irradiating magnetic field, it is possible to inspect the inside of the surface-treated product non-destructively.

Fig. 2 Schematic diagram of eddy current generation (left) and Image of measurement results (right).

2.2 Product features
This product consists of an eddy current sensor that measures a subject and application software that has sensor control and judgment functions. Further, the sensor is composed of a probe for arranging the subject and an amplifier for controlling the probe. The measurement is performed by placing the subject on the coil provided on the probe. The measurement method is the frequency sweep eddy current method, which is a measurement that sweeps the frequency of the magnetic field in one measurement. Using the frequency sweep information before processing stored in advance as a reference condition, the reaction intensity of the eddy current according to the surface treatment state is quantified by the ratio with the measurement result of the target. The right figure in Fig. 2 is an image diagram of a graph displayed by the frequency sweep result.
A measurement example is shown in Fig. 3. Shot peening (SP), which is a surface treatment, was used as the measurement sample, and a sample in which the depth of the treatment layer was changed was used. As the reference condition, the frequency sweep information before shot peening was saved. The vertical axis is the reaction intensity of the eddy current, and the horizontal axis is the value obtained by converting the frequency of the magnetic field into the penetration depth of the eddy current. As shown in Fig. 3, by quantifying the eddy current reaction with this product, it is possible to visualize the difference in the sample processing layer by shot peening.

Since the coil shape is cylindrical, an axisymmetric component such as a gear or a shaft capable of irradiating a uniform magnetic field is desirable as a measurement target.

Fig. 3 Measurement example.

3. Sales performance

In recent years, there has been an increasing demand for labor-saving and automation measures for production lines caused by coronavirus. The number of units sold in Japan is about 20, but we believe that the needs for digitization and IoT utilization with the goal of line automation will increase in the future.


Corporate Member,180-1, Komaki, Ohgi-cho, Toyokawa,Aichi, 441-1205