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Pursuing automation

Press automation helps manufacturers exceed production goals

Today, manufacturers, including those in the automotive industry, have numerous press automation requirements and options, with more on the horizon. Some automation requirements are well-defined and documented, and others haven’t yet been identified. Or they might be recognized, but manufacturers are uncertain about what automation solution to pursue.

To help sort it all out, Greenerd Press & Machine C5o. has a decades-long history of providing integrated press automation solutions for a range of manufacturers. The goal for Greenerd is to refine press designs to meet customers’ needs today as well as build in custom options that make expanding automation in the future much easier.

Recently, Greenerd received Tier 1 Authorized Integrator status with Fanuc to provide customers with a team approach (Greenerd together with Fanuc) for automation projects that require robotic handling of material and products.

Greenerd Press & Machine received Tier 1 Authorized Integrator status with Fanuc to provide a team approach for automation projects.

Automation needs

When customers approach new press projects, it is vital to understand their goals to offer press solutions that work. The challenge is to identify the proper size and scale of the automation solution to be able to address today’s and tomorrow’s production needs – all  while keeping within the project budget. As such, tailoring automation offerings to fit any application is important. This includes everything from basic press automation, such as electrically integrating a material feeder to the press, to large multi-press or multi-robot autonomous working cells.

Even in cases where manufacturers may not require automation today, it is helpful to incorporate no-cost automation pieces (“hooks,” if you will) in the press design to accommodate potential automation capabilities if needed in the future. Such options may include extra inputs and outputs on a press controller to integrate with future equipment, Ethernet communications connectivity for future press data collection or potential robotic integration, and extra controller programmable memory to expand functionality.

In instances where a manufacturer may already have one or multiple Greenerd presses, Greenerd can assist by defining current and future automation needs. Automation may be a new concept, so it might be a challenge to know where to start or what options and functionality are available for a particular application. In these cases, technical expertise is key to get projects moving in the right direction.

There are many reasons manufacturers may decide to automate their presses. Most of the time, it’s not because the press is running slow, but is a result of other factors, some of them surprising:

  • Parts demand has increased beyond the capacity/capability of manual labor
  • Personnel resources in the area are depleted
  • Press operator manpower is required in other areas of the facility
  • It’s more cost effective to automate an underutilized press than to purchase another new or used one
  • Need for more consistent product quality and quantity
  • Parts may have sharp edges, become hot or are otherwise delicate to handle

Options to meet these challenges include providing engineering support by presenting potential automation solutions, detailed floor plan layouts, targeted achievable future cycle rates and different pricing options for each. After acceptance and installation, providing on-site startup, operator and maintenance training is crucial to bring the automation solution successfully into production.

There are many ways to automate a press, from the very simple to the very complex. Examples include:

  • Adding operator production indicators for proper part loading feedback, stuck parts and part quality reporting
  • Adding a raw material feeder, controlled by the press
  • Integrating a scrap removal system or rewinder system
  • Adding automatic die loading and unloading controls
  • Installing product transport conveyors/mechanisms to load and unload the press
  • Installing load and unload robots, both large and small
  • Installing collaborative robots that work side by side with operators to perform cumbersome or repetitive tasks without any guarding
  • Adding automated inspection systems (sensors, cameras)
  • Pushing recipes (setup parameters) to a press from a remote production control system; sometimes this includes pushing production data from a press to a remote data analyzer, as well
  • Integrating multiple presses in a fully automated working cell
  • Designing and adding custom parts handling systems

Operators first

No matter the type of automation, when a manufacturer goes though the delicate process of introducing automation to a plant floor for the first time, some resistance may be encountered. The rollout of automation must be managed properly as the impact is felt throughout the organization, from human resources to accounting to IT and other parts of the front office, but it particularly impacts the production floor.

Greenerd designed and manufactured this custom 750-ton, double-moving platen deep draw hydraulic press, fully integrated with two six-axis Fanuc robots that in addition to loading/unloading, prompt the press to perform multiple operations required to produce a heavy-duty high-pressure cylinder tank.

Operators must be onboard with the change. They need to know that automation is coming to free them up to perform more important tasks – not to replace their jobs.

Most often, companies pursue automation because production needs have increased significantly beyond their current rates, and today’s historically low unemployment rates have made it difficult to hire and retain operators. It is vital that operators understand the reasons behind the need for automation.

Simply put, straight-forward, upfront communication is key. This approach has been very successful at getting people on board with the change, alleviating fear and avoiding potential backlash.

Other advancements

Today’s hydraulic presses have other features and advancements beyond automation. New hydraulic pump designs and electrical controls allow Greenerd hydraulic presses to run quieter, cooler and use less horsepower. This can be accomplished by controlling the flow and pressure on and in the pump and removing any other heat producing valves in the system. It drastically reduces the number of parts in the hydraulic system and simplifies the design, making it easier to maintain and keeping heat buildup to a minimum. In turn, this reduces horsepower and energy consumption.

Greenerd’s R&D group recently introduced new electronic flow and oil temperature sensors in its press designs. These sensors allow for more accurate control system pressures and measurement of oil temperatures. The sensor is placed at the ideal position to measure flow and heat at the same time. The benefits are faster cycle times, more precise tonnage control, and more accurate and predictable oil temperatures, all of which produces higher quality and more consistent parts.

The R&D group also introduced a new servo-hydraulic press design that incorporates an upgraded user interface that allows operators to choose press functionality by selecting simple icon-based cycle profiles. After the operator selects a profile and answers a few questions, the press automatically sets itself up for the selected operation. These custom press cycles can then be stored in more than 1,000 different recipes and recalled in an instant with the use of an optional barcode reader.

The new servo system controls the hydraulic pumps directly with a sophisticated servo motor and controller. This translates to significant reductions in energy consumption, especially in long dwell or long idle time applications and in system noise and increased platen position repeatability (less than 0.001 in.).

This can also translate into reduced costs in tool designs. With the positional accuracy of any Greenerd press, and specifically the servo-hydraulic press, manufacturers no longer need to have stop blocks built into their tool.

Part of the challenge of developing an automation solution is identifying the proper size for the equipment.

Also included with every servo-hydraulic press is the ability to constantly adjust horsepower levels to meet the requirements of the selected cycle profile with the lowest possible energy, particularly when the cycle requires long dwells under load (tonnage) or when there is a large percent of idle time between strokes. This can translate into more energy savings.

What’s in a press?

Overall, manufacturers want to buy the most reliable press they can get for their investment. Rugged construction of the frame is extremely important. Greenerd uses finite element analysis to design their frames to ensure that they can handle the cyclic loading.

Hydraulic circuits must be designed to minimize the shock that occurs whenever blanking, punching and performing other applications that cause shock. Redundant functions and components allow for a safer running machine today than in the past.

Programmable logic controllers (PLC) allow for complex programs to be written, which makes it much easier for press operators to set up specific part programs and have the PLC coordinate all the necessary valve shifts and changes to complete the cycle.

Safety light curtains with physical guarding around the work area are important. Floor scanners can also be used for mobile applications such as a gantry-style press. Safety floor mats have been used in applications where, due to the design of the press, areas outside of the actual work area of the press require guarding.

Greenerd designs and builds different styles of presses including C-frame (open gap), 4-post, gib guided, straight side, straightening and many custom designed machines to handle specific applications. Generally, the C-frame press is the most economical. This general-use press has minimal deflection concerns.

The 4-post press, however, is much better for work such as deep drawn parts, compression molding, forming, punching and other applications. The 4-post press provides superior guiding of the slide compared to the C-frame press.

Straight side presses are available in a post-guided or gib-guided slide configuration. Typically, the gib-guided version is reserved for off-center load work such as a progressive die or a part where the load can’t be centered due to the shape or design of the part.

The straight side press is also the most rugged design and generally has a much heavier build that can withstand severe loads. It is used on applications where the tool clearances in the dies are minimal, which requires an extremely precise action of the press slide to prevent damage to the tooling.

However, most of Greenerd’s presses are custom designed. This process involves starting communication with the customer to understand their needs and gather as much information about the application as possible. The company seeks to understand what the customer intends to use the press for and asks specific questions to build a detailed application specific quotation. Then, after the order is placed, the press is designed and built to not only meet these exacting needs, but exceed them by having simplified product changeovers and an easy-to-use graphical interface with their most used parameters readily accessible.

Specific customization includes designing the hydraulics and controls to achieve specific operations. For instance, manufacturers that require a high number of strokes per minute will require a completely different hydraulic circuit than one performing compression molding. Or perhaps the operation requires a high flow of oil or only a few drops of oil. Motor horsepower can be manipulated to minimize utility costs on many designs. The most important aspect, however, is building a high-quality robust system that will stand the test of time.

Greenerd Press & Machine Co.