Hydraulic press technology has advanced steadily over the years, but in small steps rather than leaps and bounds. The technology focused on improving energy efficiency, availability, automation and user-friendliness. These technological developments make hydraulic presses adaptable and flexible in a stamping environment.
As the market emphasizes clean energy, an increasing number of stamping manufacturers are now focusing on using energy-efficient equipment. Technologies such as variable frequency drives, which consume power on demand during the forming process, generate energy savings while reducing noise generation. Pneumatic timing circuits are commonly used to reduce power consumption during long timing cycles by monitoring and adjusting pressure via a pneumatic pump.
The higher the operating cost of your equipment, the more directly it affects your return on investment. Stampers are turning to the field of energy efficiency not only for financial reasons, but also for a cleaner environment.
Availability via machine monitoring
In the newspaper industry, increasing uptime is essential for on-time production. Stampers seek presses equipped with features that focus on proactive monitoring of critical press components and systems, including oil health, lubricant, pumps and motors, to minimize downtime unforeseen. Having advanced warning systems allows stampers to schedule maintenance during off-peak hours.
Automation of material handling
As the labor market tightens, more and more stamping manufacturers are turning to automated equipment. Over the past 10 years, automation has become more cost effective, pushing the industry towards fully automated work cells.
Automation can be as simple as a shuttle system or as complex as a fully automated cellular environment with robotic machine monitoring, waste disposal systems and quick tool change systems.
In a fully automated work cell, stampers can form the part completely in a cell rather than assembling it on a machine and then sending it through the facility for secondary finishing. A fully automated cell allows stampers to start with a blank and end with a complete part in one area of the plant.
Automation not only reduces the need for labor, it improves speed, throughput, part quality, and operator safety.
Simpler controls for usability
One of the greatest advances in hydraulic press technology is modern and improved controls. Previously, stamping manufacturers had to rely on skilled operators to produce consistent parts. Now, improved controls have turned the operation of a hydraulic press from an art to a science. Modern controls are programmed to be operator friendly, while maximizing part quality and repeatable forming.
With these new control systems, operations are simplified using recipe parameters that can be fully customized for each forming process. Once a recipe is created, operators have the option of entering their part number into the HMI or scanning barcodes or radio frequency identification (RFID) tags on their tooling. RFID tags use radio frequencies to search, identify, track and communicate part information to the operator. With these technologies, operators simply load the blank into the press and press the cycle start button; the equipment does the rest.
Standard hydraulic presses
While a press tailored to a stamper’s exact needs improves overall process efficiency, recent market conditions have prompted many OEMs to develop standardized hydraulic press lines. Stampers often cannot wait six months or more for a custom press due to internal goals and pressures. Purchasing a pre-engineered design increases production time and reduces upfront costs, two important factors in today’s just-in-time manufacturing landscape. On these standard lines, OEMs can pre-configure presses with varying tonnages and forming areas to work for multiple applications and industries. While some processes will always require customization, many others can be done on standard machines.
Growing industries: electric vehicles and space
With new hydraulic trends comes expansion into new industries and applications. The space and electric vehicle industries are growing rapidly, accompanied by an increased need for high-precision machinery and equipment.
In the space industry, companies use vertical integration because of the size of the components. It is rare to find suppliers with the capability to manufacture large components for rockets, so space companies source large forming equipment to manufacture their parts in-house. Production volume in the space industry is low, with around 30 parts per year formed in many cases.
In the electric vehicle industry, companies are researching and designing new propulsion systems and new batteries to accommodate fully electric cars with long-range capabilities. This includes solid-state battery suppliers who need flexible equipment to take their R&D efforts to production.
Electric servo as an alternative?
For some hydraulic press applications requiring less than 200 tons, a newly developed servo-electric press can be a good alternative.
Precision and accuracy are the main reasons why manufacturers switch to electric presses. Over the past decade, hydraulic presses have advanced in precision but still cannot compete with the precision offered by servo-electric presses. A servo-electric press maintains a position tolerance of +/- 0.0005 in. and a force tolerance of +/- 0.5%. A hydraulic press can approximate these position and force tolerances using add-ons such as proportional valves and delta motion controllers, but still cannot achieve the precise tolerances of a servo electric.
Another advantage of servo-electric presses is reduced maintenance. These presses use an electric actuator to create pressure, so the hydraulic power unit (HPU) is eliminated. Stampers don’t have to worry about pump failures, oil leaks or malfunctioning hoses on a hydraulic press or costly crankshaft and flywheel repairs on a mechanical press. Servo-electric presses can last millions of cycles before maintenance is required. Without HPU, electric presses are also quieter, cleaner and more energy efficient.
Stampers looking to switch from hydraulic to servo-electric actuation also have the option of retrofitting existing machines, reducing costs and time compared to a new press.
The limitation of servo-electric press technology is tonnage capacity. Generally the force is capped at 200 tons due to the cost of the actuators. Any application requiring more than 200 tons is currently better suited to a hydraulic press. Or if auxiliary operations require multiple cylinders, a hydraulic press is more cost effective because one HPU is capable of powering all the cylinders.
Some things never change
The main advantage of a hydraulic press remains its flexibility. Stampers have ultimate control over press tonnage, speed, cycle settings, and more. For example, if a stamper must reach full tonnage over the entire stroke to control material flow during a deep drawing cycle, he cannot use a mechanical press, which only reaches full tonnage at the bottom of the stroke. the race. Hydraulic presses are suitable for applications such as deep drawing which require flexibility and adaptability.
With all of the modernized technological advancements available on hydraulic presses today (e.g., user-friendly controls, recipe management, automation, and press monitoring systems), their forming flexibility is hard to beat.