News > Automotive Industry Increases Profitability with Innovative Hole Drilling Tools
Automotive Industry Increases Profitability with Innovative Hole Drilling Tools
Automotive Industry Increases Profitability with Innovative Hole Drilling Tools

Share on Facebook    Share on Twitter    Share on LinkedIn    Email a friend

Paul Best & Todd Cox
Allied Machine & Engineering

Read on the following sites:

Hole drilling plays a critical role in automotive manufacturing. Hundreds of holes must be drilled for each vehicle manufactured, including components like transmission shafts, engine blocks, air bag propellant chambers, camshafts, and other internal engine parts. In any automotive vehicle part production line, conveyor belts are running nonstop and efficient cutting tools are key to profitability. Every minute a machine spindle sits idle is a minute money is lost. Smart manufacturers know they need to embrace even seemingly small tooling design changes as they can make a huge difference in holemaking efficiency. Innovative cutting tool technology is now available that can be integrated right into a process seamlessly without shutting production down. Adopting these innovations can significantly increase profit margins for automotive companies.

Incorporating tooling into automotive manufacturing

In the past, all large, high-volume automotive metal cutting and drilling operations were performed with transfer lines on dedicated machines. These machines had set running speeds with large chains that conveyed parts between machining stations, where they waited for the operation to be performed. A set number of parts could be drilled in a day; in addition, if one machine broke down, the entire line shut down. There was no advantage in developing drills that sped up operations because the line was only able to run at its designated speed.

This antiquated approach to automobile manufacturing continued throughout the 1970s and 1980s but slowly began to change in the 1990s, with the rise of computer numerical control (CNC) machines. Today’s  automobile manufacturers are now using flexible CNC equipment; if parts can go faster on one machine, they can be sped along to the next one, perhaps gaining an advantage that ultimately translates into higher revenue. With these new CNC-operated transfer lines, manufacturers can be more flexible, making adjustments as needed and taking advantage of any new cutting tool advances that reduce cycle times. Without previous system constraints, auto makers can incorporate tooling innovations to help increase production and make more money. The cutting tool industry, therefore, is always developing new tool designs and coating that can help speed up production of the most time-consuming parts while maintaining quality so that these auto components don't hold back other operations. This increase in throughput can yield significant overall cost savings for manufacturers.

Industry trends affecting metal cutting in the automotive industry
One major factor affecting metal cutting in the last 30 - 40 years is the long term elimination of free-machine metals. With the removal of lead in metals and the replacement of cast iron with compacted graphite iron (CGI), the metals used in the automotive industry have gone from machine friendly to extremely difficult to machine. This means that tooling design must be adjusted to increase chip control in order to gain tool life and make the hole straighter. Other related industry changes that affect tooling designed for industrial hole drilling are the environmental laws in the United States limiting the use of chlorine and sulfur in hole drilling coolant systems. (The scope of this problem is different in Europe, which requires dry-machining, in which no coolant, or very little, is used, because elimination of waste coolant is prohibited by pollution laws.) The elimination of chlorine and sulfur has resulted in an increase in problems with chip build up on the cutting tool, chip sticking, and reduced tool life. Some companies are moving towards near net forging to avoid these issues, but the problems will continue, since parts will always differ from forger to forger.

The challenges created by these environmental improvements have inspired tooling manufacturers to find innovative ways to improve their tools' performance while supporting a healthier environment for manufacturing workers.

Innovative tools make older machines perform like new ones
In response to these automobile manufacturing, economic, and regulatory trends, the market is looking for innovations in boring and drilling – both machines and tooling. In effect, this innovation is what makes money for an automotive manufacturer.

For example, new turning and drilling machines are being introduced to the market with high-speed tool changing and more accurate HSK (hollow taper shank) style tool spindles. But there are also many opportunities to design tooling that makes up for deficiencies on older machines. Placing 21st century tooling on 20th century machines can significantly improve manufacturing efficiency and increase profitability, making older machines perform like brand new ones. Improving an existing capital asset can be a huge advantage to auto makers, since capital requests for major new equipment purchases can be difficult to fund. With the flexibility of new CNC machines, new tooling improvements can be integrated seamlessly – without shutting down the production line to retool.

One example is the engineering and design work that Allied Machine & Engineering performed for a Tier 1 supplier to a major automotive manufacturer on a high-volume transmission shaft made of steel alloy, a poor chip-forming material. The existing tool used a low tool pressure coolant system and small spindle tapers. It created a very large and abrasive chip, which trapped itself on the outer dimension of the drill’s holder body, laying in the bottom of the hole and not evacuating. With a poor hole surface finish, the tool could drill only 200-400 holes per insert and had a high monthly scrap of about $20,000.

Allied conducted the chip formation research investigation in its own laboratories – off the manufacturer’s production line and not on their spindle, so the tests didn't create any production downtime. The research lab, at Allied Machine, has the facilities to simulate the manufacturer’s exact machine conditions and pump pressures, ensuring that chip evacuation could be optimized.

The tool that Allied developed was an engineered special, a guided T-A® drill, which enables the tool to drill straighter for longer, produce truer holes, and wear more evenly. The replaceable insert drill includes an adjustable locating pin that increases tool precision, an increased bearing diameter on the holder, and additional coolant outlets in the brazed carbide bearing area of the triple gundrill holder. This design decreases the clearance between the holder and blade but increases the support of the wear pad.

This special engineered T-A drill was used in combination with a newly developed special insert, which reduces the built up edge. The insert provided the automotive manufacturer superior chip formation, improved tool life, a reduced spindle load, and a smoother cutting edge.

The combined special-engineered tooling technology enabled the low pressure machines to perform dramatically better, on par with modern high-pressure coolant machines. This drill generated very small and manageable chip formation, chips are evacuated down the holder flutes, and all rifling on the inner dimension of the shaft has been eliminated. The new tooling produces an excellent surface finish, eliminated about $240,000 per year in scrap, and increased tool life by 280 percent. Each insert can drill about 1200 holes – 3 to 6 times more than their previous tool.

Another example of innovation is an air bag propellant chamber hole drilling application Allied Machine recently worked on for an operation that produces 7 million units per year. The company was also having chip formation problems; the size of the chip was virtually creating a “barber pole” inside the part, leading to the need to scrap a great number of pieces.

Researchers within the Allied laboratory investigated the problem to understand the symptoms and then designed a tool specifically for the company’s operation and their material. They developed a tip precisely designed with the proper chip formation geometry that could make the optimal sized chip to be evacuated out of the hole. Using the special-engineered guided T-A drill body and the custom drilling insert, the customer saves three seconds per piece –and 7 million times 3 seconds saves a lot of time – and a lot of money.

This special-engineered tooling design has since been used in a variety of other automotive applications around the world, including one tool that is designed to manufacture the ends of crankshafts. A new thread milling tool and an innovative quick-change reaming head are other recent examples of how tooling can be used to gain an advantage.

With flexible modern CNC manufacturing equipment, any tooling improvements brought to market can be easily integrated. Avoiding a major retrofit that requires huge capital expenditures and tearing up facilities to install new equipment can save manufacturers large amounts of money and improve their bottom line.

See more automotive application case studies here.