Automatic testing and sorting machines and special devices for the bearing industry

Hardness Tester Autonomous MultiFrequency
– HTA MF

is an automatic independent testing and sorting machine for non-destructive examination of the hardness of steel balls.

The Hardness Tester Autonomous is intended for the automatic non-destructive examination of the hardness of steel balls. The machine sorts out the balls on the good and the bad balls from the point of view of their hardness or material. This machine has an entry hopper.

The automatic control machines type HTA MF are intended for the examination of the hardness of steel balls of diameter from range 3.0 – 6.35 mm. The HTA MF machines for checking the balls of diameter smaller than 3.0 mm and greater 6.350 mm are supplied only following a special agreement with the customer.

The machines of type HTA MF employ an induction method to test both the ball's surface and its material, they equipped with several coils (normally four coils). The device uses a method of measurement of the electrical parameters of the balls as they pass through a coil, which presents a picture of the chemical and crystalographic composition of the structure of the ball’s surface. Each coil operates at a different frequency. Each coil has its own monitoring and assessment system. Through the comparison with known, previously monitored calibration balls, the automatic machine is then able to sort balls with the precision of ±2 HRC from the calibration samples.

The machines are referred to in the document as HTA MF (MF = multifrequency) and they are supplied:

  • equipped with Hopper and Pre-Sorter for deviating diameters
  • equipped with Hopper and without Pre-Sorter for deviating diameters

The balls are fed through the machine in the following way: From the entry hopper the balls are transported through the feeder or through the pre-sorter for balls of deviating diameters (if the machine is equipped with one) and further on into the intermediate container, where their movement is regulated in such a way as to ensure that they roll singly at regular intervals through the centre of up to four monitoring coils in linear series.

According to the results of the hardness check the balls are then directed to the

  • "OK"/“UNK“ (acceptable/unknown) exit or
  • "BAD" (unacceptable) exit.

The operator can set the level of exactitude of the examination if it is necessary.

The hopper is composed of a plastic housing with an integrated ball loader and with a chute. The balls may be delivered to the entry hopper directly from customer´s boxes, containers. From the hopper the balls move to the feeder with separator which separates the individual balls. In the case of the HTA 0306 MF the balls move from the hopper through the pre-sorter for balls of deviating diameters (if the machine is equipped with one) into the intermediate container and further on to the feeder with separator which separates the individual balls.

From here the balls run through the monitoring module with four coils. Each coil has its own adjusting and testing system. The central control and monitoring unit CU TS then sorts the balls into BAD and OK/UNK. exits using the comparison of the test results with the control values (obtained previously by the monitoring of calibration balls). The OK/UNK. exit leads to the ball batcher and only in the case that the full batch of OK balls is complete and duly examined the balls are sorted as OK. In case of discrepancy (e. g. error in the number of balls etc.) the balls are sorted as ‚unknown‘ – UNK and it is possible to start the sorting process again. Balls are sorted out into the „BAD“ exit, if they were indicated as minimally unsatisfactory by one or more coils compared to the calibration samples in term of their hardness or difference of material.

The HTA MF is delivered in a left-hand configuration (the balls are fed in from the left) in the following types and ranges:

  • HTA MF : HTA 0306 MF

HTA MF are supplied as standard with the central control unit type CU TS including a graphical display of the monitoring results. The CU TS uses touch-screen controls (functions with a finger touch on the screen). The CU TS includes as standard the possibility of a printout enabling the print of an Output Protocol (i. e. a monitoring report).

The difference between the HTA MF and the HT MF is that the HTA MF is not equipped with the elevator for transportation of balls from below the base plate into the entry hopper.

Note: Packaging in wooden crates is standard for overseas shipping but can be carried out on the wish of any customer.

KROB SCANNERS s.r.o., Drahkov 52, 415 01 Teplice, Czech Republic, EUROPE >>> | Version 2006 |
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