Wheelift Automated Wheeloader

US Manufacturer for heavy wheeloaders investigates using omni-directional AGVs for chassis marry-up, hot test, trim, and wheel mount for a non-synchronous stall build line providing protection for future line process and niche model introductions with a stall build line that provides protection for future line process and niche model introductions.

Click on images for larger view and captions

Continuous improvement strategies applying lean manufacturing principals drove this design of a production system consisting of manufacturing cells linked together with a functionally integrated system for inventory and production control that uses less of the key resources needed to make Wheeloaders. The 7-key areas of waste reduction include transportation, inventory, motion, waiting time, over-production, processing itself, and defective product. Those key areas are the same for all of the major wheeloader manufacturers like Caterpillar, John Deere, and Volvo, as well as Asian manufacturers like Doosan and Komatsu.

Wheeloader Assembly

The Wheeloader assembly system is typically broken into 2-zones as here; with one omni-directional AGV serving stalls 1-5 and the other AGV serving stalls 5-10. (Each also serves as a backup for the other at a reduced throughput). The AGV moves work in process (WIP) automatically in a sequential order; i.e. stall 1 to 2, 2 to 3, 3 to 4, 4 to 5, and return empty to stall 1 providing all the benefits of an in-line process. Each stall has a "Ready Button", which the operator activates once his work is completed. This signal confirms to the AGV that it can approach the stall for pickup. A call button allows an override for immediate pickup and is set up as a "keyed operation" controlled by the line supervisor. Load exchange time is 8 minutes. The sequencing time is 55 minutes, matching the line pace supporting a lean manufacturing environment. A line rhythm is established, ensuring wheeloader production moves forward as in line-process reliability, and supports the plant's requirements for an open architecture control system with real-time system monitoring and diagnostics capability.

CHALLENGE: Conform to lean manufacturing principals and Six Sigma initiatives to replace a manually driven system for assembly of wheeloaders with an automated flexible assembly system for a 2-shift operation. A new AGV system must be easy to use, reliable, and optionally operator driven to provide the ability to react to the ever changing worldwide regional market niches.

SOLUTION: Provide a Wheelift® AGV system including two LPG powered 35-ton capacity self loading AGVs serving assigned work zones.

BENEFITS:

• Increased productivity
• Safety hazards minimized in a high traffic area
• Eliminate facility and product damage
• Production staffing flexibility
• Process flexibility
  

Wheeloader Sequenced Line Build Characteristics

• Lean Manufacturing Cornerstone
• Setting a Rhythm Driving Results
• Clear Identification of Bottleneck Operations
• Clear Identification of work in progress status driving:
  • "Continuous Improvement"
  • "Status Message" to associates
  • "Line Condition" message to Supervisors
  • "Production Plan" status to Management

   

The Wheelift® chassis module provides a degree of flexibility not attainable through other technologies. Worldwide niche markets drive manufacturing flexibility for product customization and configurable work processes. Wheelift Transporters and AGVs facilitate this requirement.

While Caterpillar is yet to actually put this into practice in their wheeloader plant, they have been highly successful with implementing Wheelift transporters into their two major Solar Turbines plants (Mabank, TX and San Diego, CA) where they build and refurbish turbine generator and compressor packages.

Wheelift Transporters and AGVs are manufactured in Iowa and are custom engineered to application specific requirements. Chassis and fixtures are available with load capacities to 500+ tons and deck heights as low as 18.5". Power options include diesel, LP gas, battery, and/or umbilical cord. Computerized all electric omni-directional drives are standard with individual axle ratings of 15, 20, or 30-ton.

Wheelift® is a Doerfer Companies technology. Doerfer engineers and builds application specific manufacturing machinery and systems. Operating from four North American locations with over 700,000 sq. ft. and 500+ employees, Doerfer offers an array of engineering and manufacturing resources and is NQA-1 certified.

SUMMATION: Stall build type assembly of heavy equipment like heavy wheeloaders can take on a whole new form of flexibility with the integration of the effortless handling Wheelift transporters and AGVs when introduced to the lean manufacturing arena in far thinking Six Sigma initiatives.

TRADEMARKS

The following terms that are used through this website: Wheelift^®, Uniload^®, SynchroSteer^®, StackAxle^®, TrackAxle™ and OmniAxle^™ are all trademarks that are exclusively licensed to Doerfer Companies.