00196044-05 - sg x und x4i fse_en - 第438页
Modular Conveyor Function Description Width Adjustment S tudent Guide (FSE) SI PL ACE X Series and X4I Modular Conveyor Edition 01/2009 EN 438 1 1.1.3 Wid th Adjustment The width is adjusted b y means of a motor as prog …
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.
Modular Conveyor
Lifting table Function Description
Student Guide (FSE) SIPLACE X Series and X4I
Edition 01/2009 EN Modular Conveyor
439
11.1.6 Lifting table
Depending on the version (single/dual conveyor), one or two independent lifting tables are used in each
placement area. The lifting table drive works indirectly via a pneumatic cylinder controlled by a 5/3-way
valve. PCBs of different thicknesses will automatically be compensated for. The PCB is guided in the Z
direction at four points on the lifting table plate. The lifting path is determined via a distance measuring
system.
The top position of the lifting table is identified by the position measuring system and a fork light barrier
for lane A and B. The check for the upper lifting table position and with that the correct clamping of the
PCB board is performed via current consumption, by approaching the conveyor motors. The lowest lifting
table position is detected by the incremental measuring system and an end position BERO on the
pneumatic cylinder. The default clearance under the PCB is 40 mm.
If you use a dual conveyor as a single conveyor you must couple both lifting tables with one another.
11.1.7 "Long Board" Option
The long boards have to be clamped twice per placement area so that each head type (C&P and Twin
head) can place components over the whole board.
The hardware is mounted on the fixed conveyor side.
Mechanical stopper
Programmable ultrasound sensor
This is mounted at one position on the fixed conveyor side of the intermediate and output conveyors.
The ultra sonic sensor is programmed for PCB recognition by placing a PCB above the sensor and
pressing the programming switch for 3 sec.
With this option the standard conveyor light barriers and lasers remain active!
11.1.8 "Alignment Pin" Option
This option is for unfavorable length/width relationship, for cut outs at the leading edge at a PCB board
or for wide and short boards. Mechanical stopper pins are mounted on the flexible conveyor side and on
the lifting table. If the jumper set for this option on the transport interface, The clamping height is learnt
with the first board, so that the pins reach the height of the board. The laser recognize the PCB board
and the conveyor stops after a defined time and the clamping is completed. The clearance under the
PCB board is reduced to 25mm.
NOTE:
To avoid board vibration during placement, use the black PCB supports (94 mm).
NOTE: X4I
This option is not available for the X4I.
NOTE: X4I
This option is not available for the X4I.