PART QUALITY ASSURANCE TUTORIAL

This system will allow selection of a distance window in which the assembly force will be monitored. A good part or bad part output will be displayed on the operator interface. If a press cycle does not fall into the parameters stored in the controller, the operator will have to acknowledge this before starting a new cycle.

Incorporates an O.I. (Operator Interface) and allows part status detection and numeric or alpha/numeric programming, storage and retrieval of the following parameters:
1) The Top Stop distance (top of stroke position)
2) The position in the stroke where the RAM switches to the pressing speed (slow-down position)
3) The distance that the RAM is to travel (bottom of stroke position)
4) The maximum RAM over travel allowed
5) The force band for an acceptable part (minimum/maximum)

Additional hardware included in this package:
1) O.I. (Operator Interface) – Allen Bradley PanelView Series
2) Upgraded PLC Allen Bradley Family of controllers
3) Load cell or Pressure transducer tonnage feedback (Dependent on accuracy needed for application)
4) Linear transducer ram position feedback

Numerous set-up recipes can be stored with this system. This system allows the operator to key in minimum and maximum force set point values and the distance window that these figures will be evaluated within. The assembly has its own force and distance feedback plus its own individual set points.

Optional Equipment

1. Statistical Process Control (SPC) Data Output – Data for one cycle can be stored in the PLC memory. After each cycle the data will then be sent to the customer’s SPC computer where it can be stored in an Excel spreadsheet format. System will generate approximately 20 force/distance data points per cycle and also give a part status bit (good/bad). Customer will need to supply all connection cabling from PC to PLC and will need to install supplied Allen-Bradley RSLinx and Excel Reporter software on their PC. RSLinx will allow connection of one PC to one PLC.

FORCE/DISTANCE MONITOR SETUP

MONITOR

The display handles the force and distance data entry. It also reports any alarms regarding the force/distance detection. The default screen at power up is shown at right:

The “GOTO” buttons will take the display to the panel indicated on the button face and are explained below. Forces determined to be too high or too low will be indicated on the image of the part by displaying the word “HI” or “LO”. In addition, the “ready” button will flash red and ask for acknowledgement before the press may be cycled again.

SETUP

The setup screen is used to enter the force and position data needed to monitor the insertion process.

The position window ON/OFF buttons indicate where the force monitoring begins and ends respectively as the assembly is made. The values entered are the amount the part engagement. As seen in the above picture, zero is where the leading edge of the bushing enters the machined bore. The GOOD PART FORCE MIN/MAX buttons are used to enter the minimum and maximum allowable forces for the good part window.

The part monitoring functions as follows: The force necessary to press a part in is monitored while the leading edge of the part is between the position window on and off points. If the force should rise above or fall below the force min. and max. values at any time between the position window points, a fault will be set and the machine will not run another cycle until the fault is acknowledged.

PREVIOUS CYCLE DATA

The data displayed here are the forces that were detected being applied to the parts at the position window on point (entry) and the position window off point (exit). This data would indicate how much the force was above or below the good part window parameters.

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