00196044-05 - sg x und x4i fse_en.pdf - 第437页

Modular Conveyor General Function Description S tudent Guide (FSE) SIPL ACE X Series and X4I Edition 01/2009 EN Modular Conveyor 437 1 1 Modular Conveyor 1 1.1 Function Description 1 1.1.1 General The standard SIPLACE m …

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Component Handling
Room for Your Sketches and Notes Control Unit on Tape Cutter (CAN Node Module)
Student Guide (FSE) SIPLACE X Series and X4I
Component Handling Edition 01/2009 EN
436
Modular Conveyor
General Function Description
Student Guide (FSE) SIPLACE X Series and X4I
Edition 01/2009 EN Modular Conveyor
437
11 Modular Conveyor
11.1 Function Description
11.1.1 General
The standard SIPLACE machine is equipped with a single PCB conveyor. A dual conveyor is available
as an option. Depending on your requirements, you can choose the left or right conveyor side as a fixed
conveyor side. The SIPLACE X4I is designed for high placement performance and is therefore only
supplied with a dual conveyor. The fixed conveyor side can be selected as required - left, right or both
outer conveyor sides (i-placement).
In the Processing Area (PA1 or PA2), the PCB board will be clamped from the bottom side against the
fixed holder on the conveyor system. The distance between the top of the PCB board and the placement
head is therefore always the same for each board, regardless of the board thickness. This has the
following advantages:
The placement rate is also no longer dependent on the PCB board thickness.
Furthermore, the fiducial recognition can be optimized,
The consistent space between the board upper edge and the PCB camera means that the PCB
camera is always optimally focussed on the upper side of the board. The PCB fiducial shape is
optimally imaged on the CCD chip of the PCB camera.
The machine height can be selected to allow the machines to be integrated into lines with a transport
height of 830, 900, 930 or 950 mm. Communication between the PCB conveyors of the different
machines is provided with the help of a SMEMA or (optionally) SIEMENS interface.
Movement of the PCBs in the input conveyor, intermediate conveyor and output conveyor is monitored
and controlled with light barriers, consisting of a sender module and a receiver module:
When the PCB reaches the placement area, the PCB is detected by a light barrier and the speed of
the conveyor belt is reduced.
About 100 ms later, a laser beam recognizes the front edge of the slowly approaching board, the
board is stopped and clamped into place from below.
11.1.2 Clamping
The PCB is lifted for placement of components and pressed up against the PCB clamping rail. When the
lifting table rises the PCB and the complete conveyor drive unit is lifted up to the clamping position.
Therefore the placement level is constant and independent of the thickness of the PCB.
Boards up to 450 mm (X series) or 380 mm (X4I) length are clamped in the respective placement fields.
Clamping does not take place on the input and output conveyor. Boards with a length exceeding 450 mm
(only X series up to 610 mm) lie with a length of 450 mm on the conveyor belt, when clamped, and are
supported in the placement area only by the lifting table.
NOTE: X4I
The maximum board length for the X4I is 380 mm. The "Long Board" option is not available in
this case.
Modular Conveyor
Function Description Width Adjustment
Student Guide (FSE) SIPLACE X Series and X4I
Modular Conveyor Edition 01/2009 EN
438
11.1.3 Width Adjustment
The width is adjusted by means of a motor as programmed. With the dual conveyor, different widths are
possible for the two conveyor tracks. The width adjustment is performed with a stepping motor and a
downstream electronics system for evaluating the step pulses. These then give the width of the conveyor
tracks.
The conveyor sides are fixed by means of a clamping unit on a steel strip.
The PCB width is adjusted via three adjustment units, they are fitted near the input conveyor, at
intermediate conveyor and near output conveyor.
The three adjustment units are moved synchronously by the stepping motor recirculating spindles
and toothed belt.
The three adjustment units are positioned under the conveyor side so that they can be moved to
adjust the PCB width. The precise position is detected by a proximity switch on the adjustment unit.
The conveyor side is mechanically connected to the adjustment unit by extending the pneumatically-
actuated fixing pins. This disables the conveyor side clamps (at the steel strip).
Once the new PCB width is reached, the fixing pins of the adjustment units are retracted once more.
The conveyor side is clamped again.
On the dual conveyor, the widths of the conveyor tracks have to be set one after the other (just one drive
for both conveyor tracks). The maximum and minimum PCB widths are protected by limit switches. If the
two conveyor sides of a conveyor lane are not parallel, this is automatically corrected during width
adjustment. The three adjustment units are moved under the fixed conveyor side and the flexible
conveyor side is adjusted according to the average value of the three adjustment unit positions. The
adjustment unit that reaches its position under the flexible conveyor side first fixes the conveyor side.
The movement then continues until the second and third adjustment units have reached their positions
and have also fixed the flexible conveyor side. The conveyor side is now registered and fixed with the
adjustment unit and the correct PCB width can be set.
The flexible dual conveyor can also be used as a single conveyor by moving lanes 1 or 2 together (max.
PCB format 450 x 450 mm for the X series and 380 x 450 mm for the X4I).
11.1.4 Checking the PCB Position on the Conveyor Sections
The positions of the PCBs are identified via light barriers (sender modules and receiver modules). The
transmitter is positioned below the conveyor belt, while the receiver is fitted above the belt, on the right.
The signal from the light barriers stops PCBs in the input conveyors, intermediate conveyors and output
conveyors.
In the placement area, the light barrier initiates the braking procedure via the D.C. motors, so that a
constant time interval is set in the software, for slow movement towards the laser light barrier.
A PCB moving control check the start- and arrival time at the conveyors. This is necessary because of
the PCB-information (bad mark -, PCB recognition) we transfer from PA1 to PA2. The operator is not
allowed to remove PCB’s from the intermediate conveyor.
11.1.5 Stopping the PCB
The PCB in the placement area is recognized by a laser light barrier. The laser beam looks for the front
edge of the board and stops it. This method prevents the impact against the stopper, which occurred in
previous cases. The positioning accuracy of the clamped PCB is +/-0.5 mm -precise enough for PCB
recognition.