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Smart Press Shop Live

Smart Press Shop Live

Schuler offers a variety of digitalization and networking solutions for forming technology – Now, the technology and global market leader in the field of forming technology offers specific solutions for the age of Industry 4.0, also known as the Industrial Internet of Things (IIOT) – like the new  MSP 400 servo press. Contributed by Schuler

The 400 ton machine is still made of genuine iron and steel and suitable for both progressive and transfer mode, can travel at an oscillating stroke of up to 70 strokes per minute thanks to the highly dynamic servo drives, and thus offers high performance in this price segment. But at the same time, it already features intelligent software applications like the Smart Assist and the Optimizer.

“Schuler is putting forming technology on the fast track to the digital future,” notes CEO Domenico Iacovelli. Schuler has designed the control of the MSP 400 in the style of an intuitive smartphone app: operators can select from predefined movement profiles or program them freely. This significantly reduces the inhibition threshold for exploiting the machine’s potential. Thanks to the kinematics of the knuckle-joint drive, forming at the bottom dead center is also slower in itself. This means that readjustment via the servo drive is not always necessary.

The “Smart Assist” software guides the operator step-by-step through the setup process, supported by small videos and text modules. The electronic assistant optimizes the transfer and slide profiles to maximum output depending on the clearance profiles – a complex process that used to take a lot of time.

At the Hot Stamping TechCenter in Göppingen, Schuler is currently conducting a field test in the area of condition monitoring. Image Credit: Schuler

Process Monitor Integrated In The Control Unit

The process monitor integrated in the control unit offers extensive monitoring options. This ensures overload protection across the entire course of the press force profile and the entire movement profile; a minimum and maximum force can be defined for effective protection of the die. The response times of the electronically designed overload protection device are in the range of a few milliseconds, which is faster than with a hydraulic overload protection device. The press can be used again immediately after an overload has been detected.

The short stopping distances and quick response times are only possible thanks to the low mass moments of inertia in the entire drive train, which also lead to high dynamics during forming and other machine operation. While standard presses normally reduce the force in the event of an overload and drive the slide through the bottom dead center to the upper reversing point, the MSP 400 has a “Smart Release” function: here, the slide automatically runs back over a defined path after an overload has been detected, thus relieving the strain on the die and press.

Comprehensive Condition Monitoring

The integration of additional sensors – e.g. for acceleration, oscillation or pressure – enables comprehensive condition monitoring of the system, which can be displayed in the control system’s visualization. The basis for this is frequency spectra that provide information about possible wear in the gearing, bearing or motor. This prevents unplanned downtime and increases the productivity of the system. Furthermore, the process and condition data allow for complete quality control of the produced components.

Unlike a conventional press, the pressure points of the MSP 400 are not above the slide, but instead on the outside of the actual bed area. This allows the machine to absorb very high eccentric loads, and means that around 25 percent more press force is available to both the infeed and discharge sides. It is therefore possible to form even high-strength materials in the first die stage.

The geometric arrangement also gives the slide a high mechanical tilting rigidity. In addition, the deflection of the entire system is reduced because the drive is located far to the outside of the crown. This makes it possible to achieve die-friendly forming and better component quality. The electronic coupling enables force-independent parallel control: in the event of an eccentric load, the drives are readjusted on one side without any loss of force, and the slide can thus be held parallel.

At the Hot Stamping TechCenter in Göppingen, Schuler is currently conducting a field test in the area of condition monitoring. © MICHAEL STEINERT FOTOGRAFIE, 

“More efficient production and fewer rejected parts”

“The digital transformation of the press shop is already well underway,” says Domenico Iacovelli, Schuler’s CEO since April 2018. He adds: “Both major automakers and medium-sized suppliers can use the Smart Press Shop for more efficient production and fewer rejected parts. This means that we can give them the competitive edge they need.”

Schuler has also already demonstrated its ability to fully network different production facilities with its systems for constructing large-diameter piping (“Pipe ID 4.0”) and train wheels. Among other things, this process requires the availability of data necessary for determining and increasing the overall equipment effectiveness (OEE). The data is prepared by the system so that a quick glance is all it takes for the production manager to determine the total number of parts produced, how many of these parts are acceptable, and which shift had the best performance.

The collected data also serves as a basis for functions like the tracking & tracing of safety-related parts. Among other things, the system links these parts to information about the starting material used and the material’s origin, about the system’s lubrication and drawing force, and about other production conditions. All of this makes it possible to provide a complete trail of documentation in the event of quality-related complaints.

To monitor the condition of individual components for changes, wear, or damage (a feature referred to as condition monitoring), Schuler is integrating more and more sensors into its machines; such as those which measure vibrations and temperatures, for example, so that this data can be intelligently processed and displayed. Currently, a large-scale field test is in progress in Göppingen involving a 1,600-ton hydraulic die hardening press, which produces parts for lightweight automotive construction from sheet metal heated to 930 °C.

Virtual Training For Operators Of Press Lines

The new virtual training system from Schuler’s Forming Academy serves as a basic training of the operators dealing with the real forming systems in the press shop. This takes place in virtual space while a new system is being put into operation or the production is already running. Thus, the production in the press shop is not disturbed and the operators can be optimally prepared.

These days, the most important thing a press shop is to deliver the demanded level of flexibility—for last-minute orders and smaller batch sizes—without sacrificing profitability. There is no other way to boost efficiency in the press shop than by carrying out an end-to-end optimization, one that also includes the entire flow of materials.

Optimizing the presses themselves is, of course, a key component of this process. What is referred to as overall equipment effectiveness, or OEE, can be determined by examining availability, efficiency and quality. By taking a wide range of different steps to increase OEE, press shop operators can tap into existing potential and increase productivity.

The “Smart Assist” software guides the operator step-by-step through the setup process, supported by videos and text. Image Credit: Schuler

Software Helps To Coordinate Slide And Transfer Movement Curves

One such step is to enlist the help of software. “The specialists at Schuler will then optimize the die and production parameters digitally,” says Schuler CEO Domenico Iacovelli, who also took over as head of Group technology upon being named to his current position. “With the help of software tools, we can perfectly coordinate the slide and transfer movement curves with each die, and can take full advantage of what the presses are capable of.”

In the span of an entire year, significantly increasing the stroke rate or decreasing the setup time will free up large amounts of otherwise unavailable production time. This additional time can be used to produce more parts on the same equipment or decrease batch sizes, and can also be used to perform preventative maintenance. This avoids unplanned downtime while maximizing availability and delivery capability.

A holistic view of the press shop quickly reveals widespread schools of thought, such as the notion that performing frequent setups decreases operating efficiency. After all, a wider variety of parts and larger batch sizes do in fact drive up warehouse volumes, and therefore tie up more capital. In order to reduce batch sizes, internal setup times need to decrease. Enormous amounts of untapped potential are waiting to be utilized with improved methods and preparation. Equally important is the necessity of storing dies in a well-maintained condition, so that sudden changes in the production plan can be responded to flexibly.

Full Mapping Of The Value Stream Improves Efficiency

As an equipment manufacturer and process consultant, Schuler partners with the lean management consultants at Staufen AG to offer extensive press shop analyses. These analyses are based on a quick check which illustrates the shop’s individual efficiency relative to the industry leaders. The analysis process involves a full mapping of the value stream for the flow of materials—from the time the materials are received all the way to the departure of the finished product from the shop—and provides recommendations for customized measures that can be taken to improve efficiency. Additionally, based on actual and target value streams, new ideal or real layouts for the press shop can be developed, both for new press shops (greenfield) and existing production facilities (brownfield).

When it comes to the actual optimization, the deciding factor is the ordering behavior of internal and external customers. In an ideal case, a press shop will produce in line with the customer’s own pace, and can therefore flexibly respond to demand fluctuations without the need for larger inventories. Running consecutively positioned stations as closely in sync as possible prevents an accumulation of large inventories and minimizes lead time.

As a general rule, permanent increases in efficiency will always take precedence over short-term, one-time effects. Huge untapped potential can often be found not only in production, but also in administrative areas such as production planning or container and shop-floor management. In the latter case, managers must have the ability to maintain regular communication while also using key performance indicators to manage and also to control processes. “The biggest benefit arises wherever process and management excellence are developed side-by-side,” concludes CEO Domenico Iacovelli.

 

Beyond Punching

Beyond Punching

Machine design, tooling and programming software combine to make today’s punch press capable of complex forms. By Dan Caprio, punching product sales manager at LVD Strippit

The introduction of the hydraulic press drive decades ago brought new versatility to the punch press – allowing the punch stroke to start and stop at any point along the ram path. The flexibility of the ram control coupled with automatic tool rotation technology opened the door to a broader range of punching and forming capabilities. The control and programming system’s ability to integrate special functions allowed users to take full advantage of the latest tooling designs, such as a wheel, hinge or bend tools.

Fast forward to the twenty-first century: the modern punch press is more capable than ever when it comes to forming, including the processing of complex, 3D parts. Today’s punch press can create bends in sheet metal that until recently only a press brake could produce.

Being able to form a part on a punch press can help significantly reduce parts costs. Bending is one of the most common bottlenecks in the fab shop, which is why shortening or eliminating the bending operation makes so much sense.

Not Your Conventional Punch Press

To form on a conventional turret punch press, you might have a feed clearance of only .984 inch or less. Part of that space is taken up by the form die, which raises the material slightly, and then you have the material thickness.

Some tools allow you to use a significant portion of that clearance, but as a rule, you can form reliably in a space that’s only 50 percent of the total feed clearance minus the material thickness. That’s not much.

New punch press designs, however, have clearances that take forming into account. Some systems make room for up to three inches of forming space from the lower dies to the upper punch. This allows for significant forming and bending, including the forming of flanges up to three inches high.

These punch presses don’t have the traditional turret setup, but instead use what is known as a tool-changer design. In the tool-changer-style punching machine, the lower carousel is underneath the brush table, and dies emerge and retract through a die to move down and out of the way between hits.

Bending Tools

This punch press design opens the door for more forming possibilities, and not just for ribs, louvers and other short forms, but also the kind of tall flanges that would normally be formed on a press brake. The bending punch and die in a punch press are a hybrid between a panel bender and a press brake, with some unique attributes. The punch looks like a miniature hold-down tool on a panel bender, while the die has a V geometry similar to what’s found on a press brake die.

The die body actually rotates during the bend. This rotation folds the workpiece against a stationary upper punch, and the die’s degree of rotation determines the bend angle. The radii you can achieve depends on the V-die design, which can be determined when ordering the tool from the manufacturer. Or, if you need to achieve a certain radius, such as for a profound-radius bend, the die rotates at certain degrees to bump the metal as the piece progressively moves forward. It’s bump bending, punch press-style.

Accounting For Thickness

Tolerances are extremely tight, both in the positioning accuracy of the machine and the machining accuracy of the tool, similar to the tolerances available on a modern press brake with precision tooling. Press operators also can input changes in thickness. Say one batch of material is on the lower end of the thickness tolerance window, while the next batch is at the high end, such as 0.055 inch for one batch and 0.061 inch for another batch.

This can make a difference in the bend angle, but as long as the operator checks the sheet thickness and makes the parameter change in the program, the machine can account for it. A change in the program code is made that tells the ram how far to come down before it performs its operations.

Besides the 3 inch height limitation, there are other constraints to consider. Unlike a press brake operator, a punch press can’t flip a part over, so a part with both positive and negative bends can create problems. Also, the angle of bend is usually limited to 90 degrees or less; acute bends greater than 90 degrees complementary aren’t practical, for the most part (depending on the tooling you have). And because of tonnage limitations, the material can be only so thick. This varies, depending on your punch press and tooling, but typically it is up to about 0.118 inches.

Programming Strategies

When you bend on a punch press, your programming options abound. Traditionally, you program the forming sequence at a point whether it won’t interfere with any other part. This usually means you’re forming near the end of a nest’s punching sequence, after most or all of the flat-part punching is completed.

At this point you may decide to bend all the flanges in a part at once. You cut the profile, leaving tabs connected to the nest to ensure part stability’ bend the flange, then perform the final punching to cut the tabs and release the part so it can slide down the chute. This strategy can work well if you want to evacuate the formed part from the nest as soon as possible to avoid collisions with the tools.

Alternatively, you can punch the profiles (minus the material for the tabs) on multiple parts – say, all the parts in one row – form the bends, then send them all down the chute with the final punches that cut the tabs. This strategy reduces the number of tool changes and so can reduce the cycle time, but works only if there is no danger of interference between the flanges and the tooling.

Consideration Of Tabs

Tabs keep the part stable during bending, but where exactly you put those tabs, their width, how many, and how they’re cut depend on the flange geometries. Some pieces may call for only a few or even just one tab at a flat section of the part. Other times the bending operation itself can break the tabs. This can be useful when bump bending. During such a sequence, the microtabs holding the part in place break, and after the last bump, the part breaks free and slides down the chute.

Programming also needs to take into account how exactly these parts slide down the chute. For example, if a large, heavy part with a high flange slides down the chute incorrectly, its landing may be rough enough to change its bend angles slightly or it may land on other formed parts with enough force to change their bend angles. You can overcome these problems by making changes to the program.

Software Makes A Difference

It’s possible to program these variables manually, but it can be complicated and time-consuming. There are plenty of details to consider, including which way to rotate the bend tool (the tool set rotates 360 degrees to align with the programmed bend lines); how to position and sequence everything to avoid interference; and which width of bending tool to use, depending on which tool you have in your library and the bend length you need.

In more challenging cases, manually programming may not be very efficient, and it actually may take you less time to form the flanges on the press brake, especially if those parts are heading to the brake anyway for a few remaining bends.

Determining Sequences

This is where the final piece of the puzzle comes into play: software that can automate the task of determining the punch and bend sequences. With such software, you can feed the 3-D model of the part you want to bend on the punch press to the software, and it will unfold the part and suggest strategies to punch and bend it, based on the tools available on the machine.

The offline program works similarly to offline bend programming for press brakes. It sees the interference points, knows just how the tool needs to rotate, and sequences it in an efficient way.

As a programmer, you can either accept the software’s recommendation or tweak it manually to suit your needs.

Beyond Punching

Tolerances are extremely tight, but operators can change parameters to suit different thicknesses.

Beyond Punching

When programming a punch press, taking into account how exactly the parts slide down the chute is important. A large, heavy part with a high flange may be rough enough to change its bend angles slightly.

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