00196044-05 - sg x und x4i fse_en - 第242页

C&P20A Overview Parts Overview with Function Description S tudent Guide (FSE) SI PL ACE X Series and X4I C&P20A Edition 01/2009 EN 242 7.2.3.3 Return unit Return unit functions At zero current, the bearing fricti…

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C&P20A
Parts Overview with Function Description Overview
Student Guide (FSE) SIPLACE X Series and X4I
Edition 01/2009 EN C&P20A
241
7.2.3.2 Z axis
Z Drive Function
Legend
1. Incremental measurement system, resolution
0.5 µm
2. Linear motor, primary part, moves up and
down between the secondary parts.
3. Light barrier Z-down emits the end position
signal for the Z axis.
4. Snap jaws: The ball bearing for the DP drive is
rotated via the star axis into the jaw, allowing
the segment to be moved upwards and
downwards.
5. Z axis fixtures
The Z axis and return unit are fixed to the head as
a complete unit, with two screws, and can be
easily replaced during service work.
Legend
1. Raceway
2. Segment
3. Ball bearings
4. Light barrier down
5. Snap jaws
The jaws are installed on the primary part of
the Z motor, for mechanical docking of the
segments.
A Z down sensor is located in the placement
position, for recognition of the Z axis put down
position. This recognizes a relative movement
between the nozzle and DP segment. When
the Z axis springs into place, this sensor sends
a signal to the axis controller board. The "light
barrier down" signal is directly linked to the
measurement signal of the Z axis incremental
encoder.
C&P20A
Overview Parts Overview with Function Description
Student Guide (FSE) SIPLACE X Series and X4I
C&P20A Edition 01/2009 EN
242
7.2.3.3 Return unit
Return unit functions
At zero current, the bearing friction of the Z axis is not sufficient to protect the axis from falling down. A
pneumatic return system has been installed to protect the Z axis should the gantry be moved when the
machine is switched off. This return unit keeps the Z axis in the safe, upper position during zero current.
7.2.3.4 Component sensor
The component sensor is a standard feature on the C&P20A head and no longer an option as in the DLM
heads. Also, the function and position of the component sensor is different to that for the DLM heads.
The component sensor is in the pickup/place position and the Z axis moves during the upwards and
downwards movement of the laser beam. If the laser beam is interrupted or when it is released again,
the exact Z axis position is read out and the corresponding evaluation started.
(Before Pick up: No Component on the nozzle, After Pick up: Component on the nozzle;
Placement: Component still on the nozzle, After placement: No Component on the nozzle)
Legend
1. Pneumatic cylinder
2. Solenoid valve
3. Compressed air connection
4. Return unit fixtures
5. Z axis driver
The return unit is installed on the Z axis and is
responsible for protecting the Z axis from damage,
by moving it into a safe area in the case of
unexpected events e.g. power cuts or machine
shutdown.
The return unit is fixed with two screws and can be
easily replaced during service work.
NOTE:
The Z axis control system is designed to ensure that, should the machine power supply fail (or
be switched off), there is always enough power temporarily stored by the Z motor servo unit and
axis controller board to move the Z axis to the upper position.
Power failure is recognized by the issuance of a "Power fail" signal. This "Power fail" signal
enables the relevant function (upwards movement and activation of the return unit) on the axis
controller board.
C&P20A
Parts Overview with Function Description Overview
Student Guide (FSE) SIPLACE X Series and X4I
Edition 01/2009 EN C&P20A
243
Component Sensor Functions
Pickup Process:
When the Z axis moves downwards, the nozzle interrupts the laser beam. At this exact moment, the
Z axis position is recorded and compared to the reference value, to see whether there is still a
component on the nozzle. If the Z axis position indicates that there is a component on the nozzle,
the Z axis will be immediately stopped. An error message will be issued or the component will be
rejected. When the Z axis moves upwards again, the laser beam is released and the Z position
recorded. Based on the Z position during downwards movement, the system can now determine the
presence and height of a component.
Placement Process:
During the placement process, the system checks whether the component is at the nozzle/whether
placement has been performed on the component.
Component sensor
In its standard state, the component sensor is
installed in the pickup-placement position on
the C&P20A head.
The sensor is fixed to the head with two
screws and can be replaced as a complete unit
during service work.
Legend
1. Power/data supply cable
2. Transmitter and receiver unit
3. Laser beam
4. Fixture to housing
Legend
1. Downwards (top diagram) or upwards (bottom
diagram) movement
2. Nozzle
3. Component
4. Read out Z position, if the IR beam is
interrupted (top diagram) or has been released
again (bottom diagram).
The component sensor determines the
component and nozzle height during the
placement process.
The component sensor signal is directly linked to
the measurement signal of the Z axis incremental
encoder.