Items in this screen are used to specify how tip wear measurement is executed and how to process tip wear related alarms. Table 2, " TIP WEAR DETECTION Screen Items " lists and describes the Tip Wear Detection screen items.
Table 2. TIP WEAR DETECTION Screen Items
ITEM | DESCRIPTION |
---|---|
The following items are where details related to the 1st step (re-master) of tip wear measurement are specified. | |
Common Setup | This item allows you to access the following items for first step of tip wear measurement.. |
Pressure Schedule | Number of the pressure schedule to use for the re-master step of tip wear measurement. Do not use this schedule for other tasks or for welding (default = 98) |
Start distance Schedule | Number of the start distance schedule to use for the re-master step of tip wear measurement. Do not use this schedule for other tasks or for welding (default = 98) |
Open Gun at Restart | ENABLE/DISABLE, specifies whether the gun is opened to the start distance before retry after a mis-detection. (default = ENABLE) |
Retry times | No. of times the re-master step is re-tried when a mis-detection is observed |
The following items are where details related to the 2nd step (fixture-touch) of tip wear measurement are specified | |
Detection Type | LOAD or DO are available. The standard tip wear measurement programs assume the LOAD technique is used. DO (Digital Output) requires an external visual sensor to measure wear instead of a fixture-touch. |
Margin of Load | This is the amount of force(load) in addition to the gun friction (measured during tip wear setup/initialization) that will be applied to detect the fixture touch. This value is set automatically by the software based on the servo gun max pressure, but the user can override this value. |
Tip Speed (mm/sec) | Set by default to 30mm/sec. This is the maximum speed the tip will close to the fixture at during the fixture-touch step of a two-step measurement. The user can increase this value experimentally if needed. This value must be set before running the TW_SETUP program, so that TW_SETUP uses the same fixture touch speed that TW_UPDAT uses. Using the same tip speed for each measurement is critical for accurate results. |
The following items must be specified for each form of tip wear measurement. | |
Mis-detect toler (mm) | Set by default to 5 mm. This is how much total tip growth (both tips combined) is acceptable between the “reference tips” and the present tips (“reference tips” are the tips that were used during initialization). If a tip growth in excess of this amount is observed it will be deemed a mis-detection and the measurement will be re-tried by the number of times listed in the “Common Setup” before posting a “Tip Wear Down misdetection’ fault. Typical values are between 5-10 mm. |
Maximum Wear Down Value (gun and robot) | This item specifies the maximum wear that can be measured on either the gun tip or the robot tip before the Maximum Wear Exceeded Warning and Inform Signal [DO] is activated. Typical values are between 5 - 7 mm. |
Inform Signal (gun and robot) | This is the digital output that is turned on when the measured wear exceeds the specified Maximum Wear Down Value. |
Increased error (gun and robot) | This is the maximum tip growth that can be observed (compared to the previous tip wear measurement) before the Tip Increased Error fault is asserted. The only case where a longer tip would be expected is at tip change. When the new tip's parameter is set to 1, the tip wear amount will be compared to zero when calculating a tip increased error, not the previous tip wear measurement. Typical settings for this item are 2 - 5 mm. |