The TCO Check for Joining Processes: Electromechanical Joining Systems

The TCO Check for Joining Processes:  Electromechanical Joining Systems

By Alexander Müller, Product Manager, Kistler

Throughout the industry, the Total Cost of Ownership (TCO) principle is a critical factor in decisions on procuring new machinery or plant. A consideration based solely on the acquisition cost as such has long since ceased to be adequate when the intention is to produce competitively in the long term. What is needed here is a TCO analysis: to obtain a complete overview of costs, this includes all direct and indirect costs incurred before, during and after the procurement of a plant or product. In addition to the actual acquisition costs, TCO includes items such as costs of maintenance and energy consumption. For example, the annual energy saving opportunities in the U.S. economy are estimated at US $130 billion.

By incorporating TCO into the purchasing decision, the most favorably priced and profitable solutions can be identified –and this principle also holds true for industrial manufacturing with joining and press-fit processes. In terms of energy balance as well as expenditure on maintenance and costs of rejects, electromechanical joining systems can be many times more cost-efficient in the long term than classical hydraulic and pneumatic technologies.

Cutting Energy Costs

The results of a university study that compares the energy efficiency of hydraulic, pneumatic and electromechanical processes emphasize the savings potential of electromechanical joining systems. With classical hydraulic applications, the energy required is 4.4 times more than for electromechanical technology – and pneumatic processes can even use up to ten times more energy. With an electromechanical solution, savings of 77 percent are possible as compared to hydraulic systems; in relation to pneumatic applications, as much as 90 percent can be saved.

These savings are possible because electromechanical systems deliver higher efficiency than pneumatic or conventional hydraulic processes. In pneumatic processes, the overall efficiency (without optimization) of a compressed air system is less than 10 percent, so processes of this sort are not energy-efficient. In many application areas, electromechanical systems offer an alternative that makes economic sense, and one that is also advisable in terms of energy consumption.

Cost Advantages During Operation

Maintenance and servicing outlay on electromechanical joining systems is minimal. This translates into increased production time, which means that the plant is more productive. With electromechanical technology, there is no need to change or dispose of the hydraulic oil – tasks that are, of course, necessary with hydraulic systems. Moreover, there is no risk of potential leaks, of the sort that occur during pneumatic processes: in the case of compressed air applications, such incidents can cause high additional costs. A leak measuring just one millimeter can cost a manufacturer US $1,100 per year. Users of electromechanical joining systems can save the costs of oil and compressed air. Low maintenance and follow-up costs mean that the investment is quickly amortized – in less than two years, depending on the specific application case.

Increased Production Efficiency

Thanks to the servo amplifier, the process can be controlled very accurately – exact positioning, constant and accurate speeds, and precisely definable press-in forces make the process measurable and reproducible. These benefits also enhance safety and reliability, and they can significantly reduce the reject rate. Electromechanical systems that make it possible to visualize and evaluate production processes are used for consistent, process-integrated quality assurance. The benefits: errors are detected in good time and the relevant product parts are separated out at an early stage. Defective parts do not undergo any further processing. In all these ways, electromechanical systems boost production efficiency across the board.

Avoiding Additional Investment Costs

More and more often, manufacturers are opting for joining systems that have the ability to perform different joining steps on one and the same plant. Here too, electromechanical applications deliver substantial benefits: they can be set up quickly and adapted flexibly to different measuring ranges, so different components can be produced on one single machine. The benefits: fewer assembly machines are needed, and investment costs for additional machines are saved.

Fit for the Future

So that manufacturers can take full advantage of the savings potentials outlined above, Kistler offers coordinated electromechanical NC joining systems with integrated force sensors and high-performance force-displacement evaluation – for end-to-end monitoring and documentation of all measured values. Manufacturers can optimize their production by detecting defective parts at an early stage. maXYmos NC evaluates and documents XY profiles for joining and press-fit processes, in conjunction with the NC joining modules and the IndraDrive servo amplifier that is included in the system. Process monitoring allows a high degree of control, so optimal cycle times can be achieved and process repeatability can be maximized. Exact positioning ensures consistently precise results.

When it comes to energy efficiency and cost-effectiveness, electromechanical systems have become the latest standard. Especially in the automobile industry and the automotive supply sector, NC joining systems from Kistler are used to minimize the inclusion of defective parts.  Twenty years ago, hydraulic, pneumohydraulic or pneumatic joining modules and drive cylinders were at the forefront of technology; but nowadays, taking Total Cost of Ownership considerations into account, electromechanical joining systems from Kistler score high marks as sustainable investments that are designed to cope with future challenges.

About the Author

Alexander Müller, Product Manager in the Electromechanical NC Joining Systems Business Field at the Lorch facility in Germany, has many years' experience of developing and using NC joining systems in the automotive industry.