Project achieved all goals and objectives. System requires two operators (one per cell). Manual process would have required 10-12 direct labor people per cell. System achieves required cycle time of approximately 24 seconds per side (for LH or RH control arms) and provides consistent, high-quality output. System only uses two dimensioning fixtures per cell, greatly reducing tooling certification efforts. Customer uses these multi-function robot cells to showcase their automated manufacturing capabilities.
Project Challenges
- Provide high productivity and minimize cycle time. Achieve production rate of approximately 24 seconds per part (550,000 parts per year, per cell, based on three shifts).
- Provide uniform welds. Parts are left-hand (LH) and right-hand (RH) upper and lower suspension control arms. Welded assemblies weigh approximately 4.54 kg (10 lbs) each.
- Fully automate process and minimize direct labor required.
Motoman Robotics Solution
Motoman Robotics provided two custom welding and material handling systems – one for LH parts and one for RH parts. Each system includes the following:
- (9) EA1400N “Expert Arc” welding robots with NX100 controllers; three groups of three robots in triple-robot control (TRC) configuration, one group each at two weld stations, and one tacking station.
- HP50 material handling robot with NX100 controller, equipped with double-ended mechanical gripper to handle two parts at a time.
- HP20 material handling robot with NX100 controller, equipped with single-ended mechanical gripper to handle individual parts.
- (2) HP6 inspection robots with NX100 controllers in dual-robot control (DRC) configuration, equipped with laser weld inspection systems.
- (9) Miller Auto Axcess 450 weld packages, including power source, interface, wire feeder and interface cables.
- (9) Motoman Tough Gun® Torch packages – 500-amp, air-cooled, with weld dress-out packages.
- (5) Torch reamer/sprayer nozzle cleaning stations.
- MSR-500 turntable – high-speed, AC servo-driven two-position indexer with two headstocks/tailstocks (mounted one on each side). Features: 500 kg (1,102.5-lb) capacity per side on 72" x 60" turntable with divider screen. Tooling axes are coordinated with the robot; can be rotated while indexing and between welds.
- Fixture package. Includes tack weld, weld out, inspection and marking fixtures.
- (2) Part marking stations.
- (2) Weld inspection stations with laser line scanning cameras.
- Programmable cell controller and MotoHMI.
- Complete cell guarding package that meets ANSI/RIA 15.06-1999 safety standard, including: 2.5-meter (8.2') perimeter safety fence; three access gates with positive-break safety switches; light curtains and roll-up door at positioner load station; and programming pendant hook switches. Perimeter guarding consists of aluminum posts with amber (arc-flash rated) acrylic fence panels on the top portion and steel panels below.
Fixtures/Tooling Details
Motoman Robotics provided two fixture packages: LH fixtures for one cell and RH fixtures for the other. In each cell, two hydraulically clamped tack fixtures are mounted to headstock/tailstocks on the indexing positioner (one fixture per side) for welding the bushings and tacking parts. Part-present and clamp/open-closed sensors are included. Motoman also provided part nests at final weld stations, laser weld inspection stations and part marking stations.
Ref: ACS-097