Electrode Maintenance; Count Factor And Wear Per Component; Fig. 28: Increase Of The Contact Surface Due To Electrode Wear - Bosch Rexroth PST 6 Serie Betriebsanleitung

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5.3.10

Electrode maintenance

Count factor and wear per component

5.3.10.1
Electrodes are subject to process‐related wear in the course of their life
(for information on wear, refer to section 5.3.10.1), and this becomes
noticeable by an increase in the contact surface, among other things.

Fig. 28: Increase of the contact surface due to electrode wear

To compensate this effect, the timer has
• automatic %I stepping (stepper; refer to page 285) and
• tip dressing (refer to page 285)
Both methods can be used separately as well as in combination.
Count factor
The wear of electrodes is dependent on different factors such as pro­
grammed %I value, thickness and material of the part to be welded.
As long as an electrode is used to make welds on one type of material
with one thickness and using the same %I value, it is possible to predict
after how many welds the electrode will be worn and in need of replace­
ment based on the existing experimental values. In this case, electrode
wear can be represented using a "spot counter". The spot counter is in­
cremented by the value "1" after each welding schedule performed.
If, however, an electrode is used for a mixture of materials or varying
material thicknesses, its wear will not progress constantly per spot
weld. A spot counter is not appropriate in this case.
That is why the wear of an electrode is monitored in the timer by a "wear
counter".
In this instance, the timer increments the wear counter by the "count
factor" after each welding schedule. This means that the wear counter
cannot only be incremented by the value "1" (like the spot counter) but
by random values.
The count factor that matches a spot weld can be specified for each in­
dividual program, thus ensuring that the electrode wear is recorded cor­
rectly.
Wear per component
Using the parameter "Wear/component", it is possible to enter the elec­
trode wear that occurs when a single part is welded. Based on this, the
timer can calculate the number of parts that can be welded by an elec­
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Information on this product
Wear
283 / 416