INSPECTION OF SPOT WELD PART

• Main Authors: NITTA SHOICHIRO, WATANABE MASAO
• Format: Patent
• Language: English
• Published: 30.05.1987
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

PURPOSE:To measure the diameter of nugget at a high accuracy, by using an ultrasonic probe with a small tip diameter. CONSTITUTION:A conical and condensing type ultrasonic probe 1 is applied on the upper surface of a spot weld part on a top board 5 of an object to be detected and the spot weld part is scanned from outside a dent thereof and again to outside it passing over center line, while beaming an ultrasonic pulse from a nugget border discriminating section 26 through a contact medium 21. In this manner, the thickness of the top board 5 is measured outside the dent of the weld part with an ultrasonic thickness meter 24 and input into an acceptance decision comparator section 28 for storing. Then, the total thickness of the board 5 and bottom board 6 are measured inside the dent to be inputted into the acceptance decision comparator section 28. When no nugget is formed, the measured value will be approximate by equal to the thickness of the top board 5 and computation is performed by the acceptance decision comparator section 28 and a display or an alarm warning of defective weld is given at a decision display section 29.