曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
a flow rate check as in (10).
If flow rate does not increase to rate of the ‘good’ side, then the master cylinder should
be replaced.
If flow rate increases to rate of the ‘good’ side, then the pedal assembly should be
removed and re-rigged.
END OF THE PROCEDURE
Technical report IN-062/2002
66
Copyright © 2003 SAE International
ABSTRACT
On Airbus aircraft, the undercarriage reinforcing is
attached through the lower wing skin using bolts up to 1-
inch in diameter through as much as a 4-inch stack up.
This operation typically takes place in the wing box
assembly jigs. Manual hole drilling for these bolts has
traditionally required massive drill templates and large
positive feed drill motors. In spite of these large tools,
the holes must be drilled in multiple steps to reduce the
thrust loads, which adds process time.
For the new A380, Airbus UK wanted to explore a more
efficient method of drilling these large diameter holes.
Introducing automated drilling equipment, which is
capable of drilling these holes and still allows for the
required manual access within the wing box assembly
jig, was a significant challenge. To remain cost
effective, the equipment must be flexible and mobile,
allowing it to be used on multiple assemblies.
In conjunction with Airbus UK, Electroimpact has
developed a mobile automated drilling system for the
A380 undercarriage area. The system can drill up to
1.25-inch diameter holes in one shot. Similar in design
to a five-axis post mill, the system can be transported to
multiple work zones using an adapted stacking crane.
2003-01-2940
Automated Wing Drilling System for the A380-GRAWDE
Scott Hogan, John Hartmann, Brent Thayer and Jack Brown
Electroimpact Inc, USA
Ian Moore, Jim Rowe and Mark Burrows
Airbus UK
The system has been termed the GRAWDE for Gear Rib
Automated Wing Drilling Equipment.
INTRODUCTION
The GRAWDE is a wing-drilling machine specifically
designed for operations in the gear rib area of the A380
wing. The machine drills fastener holes for the purpose
of fastening the gear rib reinforcing through the skin into
the rib spar structure matrix. Fastener holes in this area
of the wing are as large as 1 inch in diameter and 4
inches deep. Manually cutting these large holes is a
multi-step process using numerous pneumatic drill
motors and drill templates. In the assembly jig, this area
of the wing extends just below factory floor level. High
fastener density, numerous drill motors and templates,
and restricted worker access to the reinforcing area for
the workers creates a rate-limiting step in the wing
assembly process. The GRAWDE was designed to
address these challenges.
The key design features of the GRAWDE are:
1. Reduce labor and decrease production time by
replacing the multi step manual drilling process
with single step CNC drilling process.
2. Increase hole quality and significantly decrease
rework with automated drilling.
3. Maximize machine utilization by providing
functionality to move machine into multiple
parallel workzones.
4. Machine fits into an envelope, which allows
manual work access with or without the machine
in place.
5. Adaptive feedback provides real time
countersink depth compensation on faceted
surfaces.
MANUAL PROCESS
In the wing assembly jig, the A380 wing is fixtured
trailing edge down with the gear rib area extending
below factory floor level. A permanent reinforcing plate
is fastened over the lower wing skin and extends from
the aft tip of the wing box up to the rear spar. The 2
meter wide reinforcing plate provide structural support to
the main landing gear. The surface area of this region of
the wing amounts to approximately four squares meters
and contains approximately 250 fasteners; the majority
over 0.75 inches in diameter.
DRILL TEMPLATES
Figure 1 - Drill jig on A340 gear rib area
To achieve proper hole placement using manual
processes, drill jigs like the one shown in Figure 1 are
used. Each manual drill template consists of a
machined aluminum plate with various drill and fixture
bushings. The templates are located and fastened to
the wing skin through backdrilled holes. Due to the area,
size of fasteners, and size of the drill motors, the drill
templates are large, complex and labor intensive to use.
Figure 2 - Pneumatic drill and template
Fastener pitches are too close for the required drill
bushing diameters, which results in multiple templates
for a given area due to the overlap. These templates
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
航空资料1(133)
