The fully automatic tube bending unit combines upstream and downstream processes, combining fast, error-free processing, repeatability and safety.While this integration could benefit any manufacturer, it is especially attractive for those in the nascent but competitive field of electric vehicle production.
Electric vehicles (EVs) are nothing new.In the early 1900s, with the advent of electric, steam, and gasoline-powered vehicles, electric vehicle technology was more than a niche market.While gasoline-powered engines have won this round, battery technology has returned and is here to stay.With many cities around the world announcing future bans on fossil fuel-powered vehicles and many countries announcing their intention to ban the sale of such vehicles, alternative powertrains will dominate the automotive industry.It’s just a matter of time.
Sales figures show that vehicles based on alternative fuels have been gaining ground for years.According to the Environmental Protection Agency, the U.S. market for electric vehicles, plug-in hybrid electric vehicles (PHEVs), fuel cell vehicles, and hybrids other than PHEVs accounted for 7% of the total in 2020.This market barely existed 20 years ago.The figures from the German Federal Motor Transport Authority speak for themselves: The share of vehicles with alternative powertrains of all newly registered vehicles in Germany between January 2021 and November 2021 is close to 35%.During this period, the share of newly registered BEVs was around 11%.From the perspective of passenger cars, the growth of new electric vehicles in Germany is particularly pronounced.In this segment, the EV share of all newly registered passenger vehicles for the full year 2020 was 6.7%.From January to November 2021, this share has risen sharply to more than 25%.
This shift brings dramatic changes to automakers and their entire supply chain.Lightweight construction is a theme – the lighter the vehicle, the less energy is required.This also increases range, which is crucial for electric vehicles.This trend has also led to changes in pipe bending requirements, with a growing demand for compact and high-performance components, especially thin-walled pipes made of high-strength materials.However, lightweight materials such as aluminum and carbon fiber-reinforced plastics are often more expensive and more challenging to process than traditional steel.Related to this trend is the dramatic increase in the use of shapes other than round.Lightweight structures increasingly require complex, asymmetrical shapes with different cross-sections.
A common automotive manufacturing practice is to bend round tubes and hydroform them into their final shape.This works for steel alloys, but can be problematic when using other materials.For example, carbon fiber reinforced plastic cannot bend when it is cold.Complicating matters is the tendency of aluminum to harden with age.This means that aluminium tubes or profiles are difficult or impossible to bend only a few months after they are manufactured.Also, if the desired cross-section is not circular, it is much more difficult to adhere to predefined tolerances, especially when using aluminum.Finally, replacing traditional copper cables with aluminum profiles and rods to carry current is a growing trend and a new bending challenge, as parts have insulation that won’t be damaged during bending.
The shift to electric vehicles is causing changes in tube bender design.Traditional standard tube benders with predefined performance parameters are giving way to product-specific machines that can be tailored to manufacturers’ needs.Bend performance, geometric measurements (such as bend radius and tube length), tooling space and software are all adjusted to better match the manufacturer’s specific process and product requirements.
This shift is already underway and will only intensify.For these projects to come to fruition, the system supplier needs the necessary expertise in bending technology as well as the necessary knowledge and experience in tool and process design, which must be integrated from the very beginning of the machine design phase.For example, complex tool shapes are required to produce aluminium profiles with various cross-sections.Therefore, the development and optimized design of such tools becomes increasingly important.Additionally, bending CFRP requires a mechanism that applies a small amount of heat.
Growing cost pressures sweeping the auto industry are also being felt across the supply chain.Short cycle times and extreme precision are now more important than ever.Companies aiming to remain competitive need to use resources efficiently.This includes not only time and material resources, but also human resources, especially core employees in manufacturing.In this field, user-friendly and reliable processes are a key factor in improving cost-effectiveness.
Tube manufacturers and OEMs that handle tube fabrication in-house may respond to relentless cost pressures and other pressures by seeking high-performance machines that precisely meet their needs.Modern press brakes must use a multi-stage technology strategy that includes features such as customizable multi-radius bending tools that facilitate easy and precise bends with very short tubes between bends.This development in bending technology shines in the manufacture of tubular components with multiple radii, in the manufacture of bend-in-bend systems, or in the manufacture of other complex tube systems.Machines for handling complex bends can reduce cycle times; for high-volume manufacturers, even a few seconds saved per component can have a huge positive impact on production efficiency.
Another key component is the interaction between the operator and the machine.The technology must support users as much as possible.For example, the integration of bending die retraction – a situation where the bending die and swing arm operate separately – allows the machine to adjust and position various tube geometries during the bending process.Another programming and control concept begins to prepare the shaft for the next bend, while the current bend is still in progress.While this requires a controller to continuously and automatically monitor the interaction of the axes to coordinate their movements, the programming effort yields huge benefits, reducing cycle times by 20 to 40 percent depending on the components and desired tube geometry.
Given the shift to alternative powertrains, automation is more important than ever.Tube bender manufacturers need to focus on extensive automation and the ability to integrate workflows beyond bending.This applies not only to pipe bends in large-scale series production, but also increasingly to very small series production.
Modern press brakes for high-volume manufacturers, such as the CNC 80 E TB MR from Schwarze-Robitec, are ideal for the requirements of manufacturers in the automotive supply chain.Attributes such as short cycle times and high resource efficiency are critical, and many manufacturers rely on options such as weld inspection, built-in cut-off and robotic interfaces.
In fully automatic tube processing, the various stages of the process must be reliable, error-free, repeatable and fast to ensure consistent quality of the bending results.Upstream and downstream processing steps must be integrated into such a bending unit, including cleaning, bending, assembly, end forming and measuring.
Handling equipment such as robots and additional components such as pipe handlers must also be integrated.The main task is to determine which processes are most suitable for the relevant application.For example, depending on the manufacturer’s requirements, a belt loading store, chain store, lift conveyor or bulk material conveyor may be the right system for a tubular feeder.Some press brake manufacturers make integration as easy as possible by offering proprietary control systems that work in conjunction with the OEM’s enterprise resource planning system.
Although each additional step makes the process chain longer, the user does not experience any delay as the cycle time generally remains the same.The biggest difference in the complexity of this automation system is the stringent control requirements required to integrate the bending unit into the existing production chain and company network.For this reason, pipe benders should be ready for Industry 4.0.
Overall, integration is the most important.It is critical that OEMs work with machine builders who have extensive experience in developing machines that are compatible with the various subsystems in a fully automated manufacturing process.
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