Product Description

An automotive OEM parts supplier required an automated end-of-line production test system to provide an accurate metered air flow supply through a new generation of automotive engine throttle chambers. This workstation provided the final quality control checkpoint for 100% of all manufactured units, so accuracy, repeatability, throughput and availability were critical elements in the design of the test system.

System Requirements

• Vacuum Flow at Two Discrete, widely separated Nominal Flow Rates
• Automated Control of Throttle Body valve motor positioning
• Part Fixturing, including air flow inlet section and Unit Under Test mechanical/electrical mating connector
• Database for all setup and calibration data, as well as for all production test results data
• Meet Production Line Cycle Time Goals of 1 part every 30 second
• Expandable and Flexible Data Acquisition and Control sub-system
• Expandable Air-Flow metering system and Instrumentation
• Operator Safety Interlock devices to comply with all regulatory requirements
• User-friendly Test System Controller Software for Operator, Maintenance and Engineering personnel

Solution Description

Flow Systems designed and manufactured an air flow test system that employed two sonic nozzles (also called “critical flow venturis” or “critical flow nozzles”) housed in a plenum to meter the air flow through each throttle chambers. The air flow plenum design featured a unique by-pass valving arrangement for the smaller nozzle. This reduced the mass flow stabilization time by significantly decreasing the system volume. This design ensured that cycle time requirements could be met or exceeded.

Flow Systems also designed custom Unit Under Test part-placement fixturing, including the design of the mechanical/electrical connector that automatically mates with the Unit Under Test to provide the necessary (electrical) motor control signals.

Operator safety issues were addressed through the use of thumb-activated switches to start each test cycle, and the use of “light-curtain” technology to ensure point-of–operation work area guarding.

System Specifications

• Flow Elements: Two Critical Flow Venturis (Sonic Nozzles), 1 spare position for expansion.
• Flow Range: 15 & 385 (actual) liters per minute
• Accuracy: 0.5 % of reading, traceable to NIST standards
• Repeatability: 0.2 % or better (20 successive measurements)
• Cycle Time: < 28 sec.

System Customization

This product is an example of a custom system developed and manufactured by Flow Systems. System hardware, controller software, fixtures, and facility requirements can all be configured to meet specific customer requirements. Custom test stands manufactured by Flow Systems are built using industry standard Commercial Off-The-Shelf (COTS) components utilize flow meters which are traceable to National Institute of Standards and Technology (NIST).

Photos & Schematics

The following are pictures and schematics of the Throttle Body/Chamber: Production System.

Production System