PRELIMINARY DATA IN-PROCESS BALL GAUGE

PRELIMINARY DATA IN-PROCESS BALL GAUGE

The In-process ball gauge provides ball manufacturers the ability to continuously monitor ball diameter during the production process. Outputs are available to signal the current diameter zone of the parts in the grinding process. The system eliminates the need for continuous sample lot inspection by the operator as well as scrapped lots resulting from grinding past the desired diameter. The process can be optimized by means of contact outputs to the grinder control unit to allow full control of cut rate throughout the ball grind cycle.

The unit is supplied as a pedestal mount unit anchored to the floor in a position which will allow the feed/gauge mechanism to capture balls from the grinder tub. The system instrumentation and control electronics are provided in a sealed NEMA enclosure which is mounted to the pedestal as well.

The unit feed mechanism is linearly settable over the tooled diameter range of the gauging system. The device will automatically pick up a ball from the mass of balls in the grinder tub and present it to the gauge mechanism. Once the ball has been gauged the feed mechanism will return it to the tub and retrieve another one to be gauged.

The gauge mechanism consists of a precision carbide Vee equipped with an opposing LVDT measuring probe. The probe is of a sealed type equipped with a positive pressure air supply to minimize contamination by the process coolant mist. During a measurement cycle a fixed pressure pusher will push the part against the movable anvil. The moveable anvil is controlled by a stepping motor which allows for moving the ball past the measuring probe at a known increment per step. For each increment the LVDT is read until a maximum reading is encountered. A number of readings are then taken past this maximum and the data set is then fit to a best fit quadratic. This equation is then solved for it’s maximum and this value becomes the diameter reading for the part for that cycle. A part at the gauge position may be measured again any number of times with the overall average of the measurement used as a single diameter measurement. This measurement is further compensated for the process tub temperature as well as the gauge fixture temperature from the time of calibration to a master.

During operation the overall average of the last N measurements are formed and this value is applied to preset limits which in turn activate one of the four contact outputs to the grinder control unit as an indication of the process progress.

SPECIFICATIONS:
Mounting:…………………………………………………………Pedestal Type Floor Mount
Foot Print:………………………………………….………………1’ X 2’ X 5’ Max. Height
Power Requirement:……………………………………………………115VAC, 60HZ, @2A
Pneumatics:……………………………….…………………Shop Air @60PSI, 1SCFM Max.
Cycle Time:……………………………….………………6 Seconds/Part Max. (user settable)
Part Range:………………………………………………………………Two Tooled Ranges

(range 1:1/8”-1/2” diameter)

(range 2:1/2”-2” diameter)
Sensor:………………………………………………………………………Precision LVDT
Repeatability:……………………………………………………………………..+/-.000002”
Accuracy @ Final Size:…………………………………………………..……..+/-.0000004”
Features:…………..Temperature compensated for process temperature and fixture temperature
Display:…………………………………Four line X sixteen line Alphanumeric LCD display
Keypad:……………………………………………………Sealed membrane alphanumeric type
Outputs:……………..………..Four contacts for current diameter feedback to grinder controller