Real-time contact free examination of internal threads

The optical measuring system is able to examine the entire internal thread. Examination normally takes place using four inspection windows which check the entire thread length and are spaced every 90° around the thread circumference.
The examination checks the completeness and the regularity of the thread.
If necessary, the position and the number of inspection windows can be adjusted to suit special requirements.
The image shows a flawless thread on a wheel flange. All five threaded holes in the flange (M14 x 12 mm) were examined in real time while the flange was turning. The image shows a single threaded hole with four inspection windows and the associated four analysis windows. The camera software analyzes the optical data in real time and displays the results in the middle of the image. Galvanically-isolated outputs allow the result data to be passed on to production control equipment.


Features
- Real-time thread analysis using an intelligent CCD camera without interrupting the production process
- The image processing software is integrated in the camera - no external PC required.
- Galvanically-isolated inputs and outputs for interfacing to existing production control equipment.
- Includes compact optical measurement head with special lens and illumination.
- Easy to integrate in existing test and manufacturing equipment.
- The image processing software can detect the following thread faults:
       Thread not present
       Thread not complete
       Thread not regular (incorrect spacing between the crests)
- The complete thread is checked and scanned at regular intervals
- The system can check the bottom of blind threads for cracks, metal chips, rust etc.
Example of a faulty thread, M14 x 12 mm

Thread flanks missing completely or partly missing
Faulty thread on a wheel flange
Example of a blind hole with thread, M4 x 4.5 mm Example of a blind hole with thread, M4 x 4.5 mm
Faulty thread without proper flanks Correct number of thread flanks detected by the inspection windows - thread is OK
Example of a blind hole with thread, M4 x 4.5 mm Optical measuring equipment for thread sizes M4 - M6, 2 - 5 mm long.
Metal chip detected - thread is faulty Equipment for optical control of the internal threads and the component height


Advantages:
- Conventional optical systems only look sideways into the hole. Flaws at the beginning and end of the thread can be overlooked.
- The number of inspection windows (normally four) can be increased if necessary.
- Due to the small size, the system can be easy retrofitted to existing manufacturing equipment.
- The examination can take place during running test and production processes.
- Statistical information such as the number of rejects and the reject frequency can be shown on the screen.
Examples of use:
- Examination of through-threaded holes, e.g. on wheel flanges, threaded inserts and special section tubes.
- Examination of blind threads, e.g. on cylinder heads and gearbox components.
- The system is normally configured for thread sizes from M8 to M14, 4 - 15 mm long; other thread sizes are available on request.