To provide a method for determining hardening of an adhesive that determines the hardening of the adhesive based on an adhesive for sticking parts to be stuck incorporated in an actual product, and determines the hardening of the adhesive for each part of the product.
This method comprises a first step S1 of detecting the sound velocity of ultrasonic wave in the adhesive and the amplitude of ultrasonic wave having passed the adhesive by oscillating the ultrasonic wave toward the adhesive 7, and a second step S2 of determining whether the sound velocity or the amplitude detected in the first step S1 varies by a predetermined rate or more from a reference value as the sound velocity or the amplitude before the hardening of the adhesive, and, when it varies by the predetermined rate or more determining the hardening of the adhesive. Until the hardening of the adhesive is determined in the second step S2, the first step S1 and the second step S2 are repeated.
YAMASHITA SEIKI
Yasuharu Nakasone
Toshihiro Nomura