80S-15贴片机 - 第315页

SIPLACE 80S/F/G Service Manual 9 Revolver Head Edition 04/97 9 - 31 "Com pon ent p rese nt / no t pr esen t" (p lac ement cycl e) The vacuu m sensor of the p lacement circuit ( see Fig. 9.5 .5) de termines the …

9 Revolver Head SIPLACE 80S/F/G Service Manual

Edition 04/97

9 - 30

The vacuum threshold value "Good nozzle contact" lies below the maximum vacuum value while the value

"Bad nozzle contact" lies above the minimum permissible vacuum value. At the same time the values

"Vacuum limit value for permissible leakages while segment closed" and "Vacuum threshold value for the

permissible contamination of the nozzle when the segment is open" are entered.

NOTE

If a nozzle is defined in the machine data file AKTUELL.MA for a segment as invalid or not present, no vac-

uum measurement will be made at that segment. This measurement is first activated in the nozzle change

menu during setting up.

9.5.4.2 Monitoring the Vacuum during Pick-Up and Placement Cycle

In the monitoring of the vacuum the actual values of the vacuum are measured during the pick-up and place-

ment cycle of the revolver head and compared with the values specified by the program or computer specified

- and which had been determined in the reference run.

If the specified values are not achieved, then the conclusion appropriate in each case will be drawn, such as

"Warning", "Closure of segment" or "Fatal error messages".

The vacuum obtaining in each case is measured by the pressure sensors of the placement and ejection

circuits as follows:

1. Vacuum sensor of the placement circuit "Component picked up / not picked up" (pick-up cycle)

"Component present / not present" (placement cycle)

"Component picked up / not picked up", measurement during the pick-up cycle

The sz axis positions itself with sensor stop upon the component which is to be picked up. Only after the end

message of the sz axis for "Nozzle is positioned on the component" is received is the nozzle opened and the

component sucked up. The vacuum is measured after the component has been picked up and after the sz

axis has moved up in revolver head position "1".

If the threshold value "good" or "bad nozzle contact" is not achieved this means that either there is no compo-

nent at the nozzle or too much air is being sucked in at the nozzle due to an incorrectly positioned component.

If no component has been picked up, the revolver head cycles the segment on to the reject station. The

revolver head here moves over the collecting container and ejects the incorrectly positioned component. The

sealing piston closes the segment. Next, the vacuum test is carried out for permissible airtightness and con-

tamination (optimized vacuum sequence). The revolver head cycles on to the pick-up and placement station

and tries once more to pick up a component. If this attempt also fails, this will be added to the "Not done" list.

If access to a component on the conveyor is unsuccessful three times in succession the conveyor is set to

"Track empty" and the track error displayed on the screen. The placement sequence will however only be

halted when the PCB is completely assembled with the exception of the missing components.

SIPLACE 80S/F/G Service Manual 9 Revolver Head

Edition 04/97

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"Component present / not present" (placement cycle)

The vacuum sensor of the placement circuit (see Fig. 9.5.5) determines the current vacuum value in revolver

head position 1 during the placement cycle of the revolver head in each case before lowering of the sz axis.

If the threshold values for "Good and bad nozzle contact" are not reached, the component at the nozzle in

question will be lost. The sz axis remains in its top end position. The revolver head cycles the segment on with

open segment to the revolver head station 3. Here the segment is closed. The lost component is added to the

"Not done" list.

NOTE

The sz axis will also stay in its top end position if a component has been sucked onto the nozzle with a CRDL

measurement error, rotating or centering error. In revolver head station 3 these components are ejected dur-

ing the ejection cycle into the rejects container.

2. Vacuum sensor of the ejection circuit:

Good or bad nozzle contact?

Nozzle clogged?

Segment sealed?

The vacuum sensor of the ejection circuit (see Fig. 9.5.5) determines for the segment in question what the

vacuum is in revolver head station 3 and compares the actual value with the setpoint vacuum value specified

in the program.

During the measurements at revolver head station 3 a distinction is made between the pick-up and placement

cycles of the revolver head, as was already done with revolver head station 1.

"Good or bad nozzle contact?" (pick-up cycle)

During the pick-up cycle of the revolver head the vacuum sensor of the ejection circuit measures the vacuum

obtained in revolver head station 3 in each case when the revolver head division position is reached. By

means of a comparison between the measured value and the value specified by the computer for "good" and

"bad nozzle contact" (see Fig. 9.5.6) the form of the picked-up component is compared with the form specified

in the program.

If the threshold values are not reached for "good" and "bad nozzle contact", the component in revolver head

station 3 will be blown off into the rejects container and added to the "Not done" list.

"Nozzle clogged? Segment sealed?", measurement during the pick-up cycle

Immediately after ejection of the component due to vacuum errors, in revolver head station 3 the nozzle will

be checked for contamination and the segment for leaks. The sealing piston then closes the segment. In this

way, when the revolver head cycles on, the vacuum in the holding circuit is maintained.

"Nozzle clogged?" (placement cycle)

The final measurement during the placement cycle of the revolver head is the "nozzle clogged?" check in

revolver head station 3 of the ejection circuit.

If there is still a component at the nozzle, this indicates CRDL measuring errors, centering or rotational errors,

which are to be found in the program. The component will be blown off by the nozzle into the rejects container.

If a nozzle arrives without a component when the segment is open, then the sealing piston will be moved

forward.

9 Revolver Head SIPLACE 80S/F/G Service Manual

Edition 04/97

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For the vacuum measurement which now follows the sealing piston is retracted - in other words, the segment

is open. If the measured vacuum value is better than the vacuum limit value for permissible contamination

with open segment specified in the MA data of the placement program (see Fig. 9.5.6), then the nozzle is

clogged. However a certain amount of contamination is permissible.

If the measured vacuum value exceeds the permissible limit value, the clogged nozzle will be segregated by

the program and the following error message displayed on the screen:

"The nozzle in the reject station for the gantry and segment is clogged."

Since the component can no longer be inserted, it will be added to the "Not done" list. If the nozzle is still

defective at the second check, the placement sequence will be aborted.

9.5.5 SZ axis

The following modules belong to the sz axis:

–

16 mm lifting slide (see Fig. 9.5.7)

–

bero: interrogation whether the sz axis has reached the top end position (see Fig. 9.5.1)

–

longitudinal guide of the lifting slide (see Fig. 9.5.7)

–

sz axis drive (see Fig. 9.5.8)

–

segment claw (see Fig. 9.5.9)

9.5.5.1 16 mm Lifting Slide

The 16 mm lifting slide slides in guide rails which are fastened to the lifting slide housing. Two deep-grooved

ball bearings roll on the sz-cam disk and thus convert the rotational movement of the sz-drive motor (see

Fig. 9.5.8) into a lifting movement of the lifting slide.

To pick up and insert components the lifting slide lowers the segment into revolver head station 1. To cycle

the revolver head on and thus to move the segments to the individual stations of the revolver head, the lifting

slide raises the segment up as far as the top end position. Once the sz axis reaches the top end position, the

tripping face (see Fig. 9.5.7) of the sz axis activates the bero "sz axis in top end position". The end

message generated by the bero signals that the revolver head can cycle on.

9.5.5.2 Longitudinal Guide of the Lifting Slide

Two rails which hold loose ball bearing cages at each end form the longitudinal guide of the lifting slide. The

rails are set in the factory to ensure the lifting slide runs without any play.

NOTE

Do not undo the yellow-painted locknuts and setting screws for the longitudinal guide of the lifting slide (see

Fig. 9.5.6), otherwise you will have to have the longitudinal guide reset in the factory.