Method and apparatus for assessing the quality of spot welds

• US 20040245315A1
• Filed: 06/04/2003
• Published: 12/09/2004
• Est. Priority Date: 06/04/2003
• Status: Active Grant

• Current Assignee: FCA US LLC (Stellantis NV)
• Original Assignee: Chrysler Group LLC (Stellantis NV)
• Inventors: Maev, Roman Gr., Maeva, Elena Yu, Ewasyshyn, Frank J., Paille, John M., Seviaryn, Fedar M., Denisov, Alexey A., Titov, Serguei A.
• Granted Patent: US 7,789,286 B2
• Time in Patent Office: Days
• US Class Current: 228/8
• CPC Class Codes: G01N 2291/02827 Elastic parameters, strength or force
• CPC Class Codes: G01N 2291/02854 Length, thickness
• CPC Class Codes: G01N 2291/044 Internal reflections (echoes), e.g. on walls or defects
• CPC Class Codes: G01N 2291/106 one or more transducer arrays
• CPC Class Codes: G01N 2291/2672 Spot welding
• CPC Class Codes: G01N 29/262 by electronic orientation or focusing, e.g. with phased arrays phased arrays per se G10K11/34

Abstract

A method and apparatus for evaluating the size and/or quality of a spot weld. The apparatus includes a two-dimensional array of ultrasonic transducers arranged with a delay line for positioning adjacent a surface of a weld. A layer of gel is placed between the delay line and the weld surface. The array of transducers emit ultrasonic waves that pass into the weld. The reflected waves are received by the transducers and relayed to a central processing unit that analyzes the time delay, amplitude, and amplitude attenuation to calculate the border of the weld nugget, the thickness of the welded material, the thickness of the gel layer, and other factors contributing to weld quality.

Claims

1. A system for detecting the structure of a weld, comprising:

a plurality of transducers for generating a series of periodic ultrasonic waves for transmission into a welded body, the plurality of transducers being arranged in a two-dimensional array;

a multiplexing apparatus for directing transmission of an ultrasonic wave from each of the plurality of transducers and for receiving return signals from the transducers;

a hard delay line adapted to contact a surface of a welded body in a known manner and with a known orientation;

a computer control system for directing the transmission of ultrasonic waves, and for receiving and interpreting data received from the transducers; and

a display unit for visually indicating interpreted data from the computer control system.

2. The system of claim 1, further comprising a computer server architecture adapted to receive interpreted data from the computer control system and adjust a control program for a spot welding system.

3. The system of claim 1, further comprising a memory module for recording a received data set representing a detected weld structure, the data set including at least one of a nugget size, a depth of indentation, and a presence of inclusions in the weld.

4. The system of claim 3, further comprising an automated component for spot weld image analysis, including identification of weld nugget, stick bonded zone and delamination zone

5. The system of claim 1, further comprising an automated component for spot weld image analysis, including identification of weld nugget, stick bonded zone and delamination zone.

6. The system of claim 1, wherein the data received from the transducers is processed to determine indentation mark depth under each transducer from both sides of the weld for reconstruction of indentation mark shape and calculation of a transducer tilt value for each transducer.

7. The system of claim 6, wherein the data received is interpreted to obtain two-dimensional spatial distributions of amplitudes and attenuation factors for the reflected wave, correcting this data according to an estimated surface and transducer tilt value, and the display unit visually indicates the interpreted data as gray-scale or pseudo-color images.

8. The system of claim 1, further comprising a manual control mechanism adapted for adjusting the position of the plurality of transducers with respect to the welded body.

9. The system of claim 1, wherein the computer control system is adapted to interpret data received by comparison to calibration relationships obtained from correlation of ultrasonic measurement datasets with destructive testing.