Automation and Control Upgrade of In-Line Production Test

The Challenge

This global manufacturer of diesel engines is committed to continuous improvement. The company constantly fine-tunes its assembly line to improve throughput.

In-line engine production quality leak testing was only able to test two engines at a time, bottlenecking the engine production line. ACS engineers were tasked with developing a way to run more simultaneous production quality in-line tests.

In modifying the line for more testing, engineers had to carefully optimize the work flow around the line. The large diesel engines are moved down the line via forklift, so it was important to leave enough space for forklifts to pick up, drop off, and transport engine pallets quickly and safely.

The Solution

The first thing ACS did was double the number of production quality in-line tests that could run at a time, from two to four. Engineers then went a step farther. To reduce idle time, they configured the in-line test so while four engines are being tested, the next four are being hooked up to the testing apparatus. As soon as one set of tests ends, the next can begin with no lag time.

To accomplish this, ACS designed four boom arms. Each retractable arm hangs over an engine in testing and includes all of the tools needed for the test. The design improves efficiency by eliminating the need for operators to fetch and return tools from a central location. Engine production quality leak testing involves heavy air tools, so the boom-mounted tool trolleys and balancers promote worker safety and minimize fatigue.

“As soon as the engine is there, the operator slides it over. All the tools the operator needs hang inches away from where they hook up on the engine, so everything is within reach. Operators don’t have to get tools from stations or anything like that,” said Andrew Harris, ACS Instrumentation Control Engineer.

ACS also integrated a safety PLC for automation of the in-line production test and control of the devices. Once the operator has the engine in place, automated traffic lights indicate to forklift drivers that the bay is closed. When the test finishes and the testing apparatus is removed, the traffic lights change so drivers know the engine is ready to pick up and move to the next area of the line.

In the previous engine production quality leak test, engines were moved from a conveyor to a chain hoist that pulled them through the leak test before they were palletized and moved to the next station. The new system palletizes them right off the conveyor, so the leak testing integrates seamlessly into the next phase of the line. This simple swap yields cost and time efficiency.

The entire project was installed, integrated with the existing leak testing equipment, and verified during the manufacturer’s regularly scheduled two-week shutdown over the winter holidays. When operators returned to work after the break, the system was ready to go.

Outcome

Three years after its installation, the four-bay in-line testing system has had zero faults and zero downtime. With engines moving through production quality in-line testing more than twice as fast, the manufacturer was able to turn its attention to more complex challenges slowing down the line.

Key Features

• Master Control Cabinet (MCC) to house the Siemens PLC for safety and control of devices integrated into the automated leak test process
• “T” shaped boom arms include tool trolleys mounted on the booms and tool balancers to promote operator safety and minimize fatigue
• Integration of leak test equipment to improve takt time

ACS Services

• Designed and built custom boom arms
• Integration of leak test equipment, controls, mechanical systems
• Oversaw installation by client’s skilled trades
• Factory Acceptance Testing (FAT) of the integrated system (leak testers, controls, scheduling software, and MCC)